Cannabis Grow

The increase of phosphorus in the minesoil was in line with organic matter content increase.Soil organic matter plays an important role in P sorption as the main constituent of the soil sorption complex which is responsible for binding of anions in the soil material.Phosphorus leaching can be significantly affected by soil adsorption-desorption properties,and it has been shown that application of organic fertilizers could significantly improve the soil phosphorus adsorption capacity.Mengmeng et al.found,that organic fertilization together with mineral NPK increased available phosphorus by 150 % comparing to NPK alone.Application of organic matter is also supposed to improve the soil phosphate availability by promoting microbial activity.The increase in potassium content was slowier than that of phosphorus.During the first three years,this increase was not statistically significant.It was only in 2017 that a statistically significant increase in the potassium content was noted,to the level of 95 mg kg of soil.In the last year of the experiment ,the potassium content reached the value within the norm for this element,ranging from 120 to 200 mg,reaching the value of 175 mg kg of soil.Disturbance to soil by mixing subsoil with topsoi may decrease potassium content.In the studied soil the initial amount of K was very low.On top of that it is known that potassium readily leaches from organic matter as it decomposes.found,that when staw was left on the field,most of its K content was leached during the first month of storage.That can explain the delayed increase of this element level in the course of soil remediation – even though annual potassium fertilization was used.On the other hand hemp is known to take up potassium when the element is not needed and hemp has a lower requirement for potassium than other crops.Most of the absorbed potassium absorbed by Cannabis is concentrated in the stem.

That could explain the finally observed increase of the potassium in the studied soil as this part of the plant is particularly resistant to decay due to the high content of celulose and lignins and could store the absorbed amount of potassium.It is worth noting that the content of phosphorus and potassium reached a value above the lower limit of the norm for these elements only after three and four years of soil rehabilitation respectively,cannabis grow tent despite the annual intensive fertilization with these elements.This confirms the important role of organic matter in the absorption of potassium and phosphorus in the soil.A significant increase was also observed in the case of magnesium content.In the base year,the magnesium content was below normal and amounted to 40.6 mg kg of soil.The level of macro-nutrient gradually increased and in 2017 it amounted to 92 mg / kg of soil,reaching the value of 119.2 in the last year of the study.The standard for the content of magnesium in the soil is from 61 to 100 mg kg.The rate of movement of magnesium in soil depends on soil texture,rainfall and soil pH.It is generally believed that it is easy to migrate in neutral to acidic soil and difficult to migrate in alkaline soil.That suggests that soil conditions in the course of the experiment were in favour to limit leaching of this element and as a result progressive absorption within the organic matter delivered into soil.The manganese content in the tested soil increased in the years 2015–2017 as reclamation was carried out and fell within the norm,which is from 85 to 830 mg.This increase was statistically significant.Also,comparing the base year with 2017,a significant increase in the level of manganese in the studied soil was observed.It has been reported that soil Mn was primarily found in the exchangeable and organic fractions,regardless of soil pH but solubilization of organic acids under alkaline conditions may result in increased complexation of Mn inhibiting its precipitation in the soil environment.It has been also observed that stronger bonding of manganese ions by organic matter was induced by increased soil pH.These previous observations well explain our results showing that Mn content in the soil directly followed changes in the soil pH.The boron content in the soil varied in the studied period.Its level increased significantly from 0.41 mg/kg of soil in 2014 to 0.99 mg/kg of soil in 2017.There was no significant change in the boron level between the starting year 2014 and 2015.Between 2015 and 2016,a significant increase of this micro-nutrient content was observed.Despite the increase,the content of this micro-element was below the standard for Polish soils,which ranges from 2.2 to 7.2 mg kg of the soil.

Although many investigations have been performed with the influence of certain constituents on boron behavior in soil,there is no general agreement on the role they play in B adsorption and desorption.There is general belief that organic matter plays an important role in B adsorption and its availability in the soil.Besides organic matter,also soil pH plays an important role in B behaviour in the soil environment.Gu and Lowe found that B adsorption by humic acids was strongly pH-dependent,being low and relatively constant in the pH range 3.0–6.5,increasing markedly up to a peak at near pH 9.5,and then decreasing at higher pH values.It has been concluded that complexation of B with soil organic matter should only be important at alkaline pH.Our results are in agreement with those previous observations.We have noted the increase of B content in the minesoil together with organic matter accumulation and with soil pH increase.In recent years there has been a development in many areas of plant fibre-based materials ,which has led to an ever-increasing demand for flax scutched fibres,particularly in Europe,which produces 80 % of the world production of flax and hemp.A study conducted by ADEME,the French environment agency,in 2015 predicted that it would be necessary to sow 145,951 ha of fibre crops in France by 2030 in order to meet the demand.This would represent about 1,000,000 tons of straw.In 2018,a total area of only 107,000 ha of textile flax was cultivated in Europe,including 89,000 ha in France.Due to the need for a mild and humid climate and long crop rotations with flax cultivation being repeated on the same land only once every six to seven years to avoid soil depletion and the proliferation of diseases ,the traditional flax production areas are at their maximum production capacity and cannot satisfy an ever-increasing demand for flax fibres.It is therefore necessary to find an additional crop to increase the production of high added value fibres for textile and technical applications to reach the targeted surface of 145 000 ha suggested.In the past,hemp was cultivated for such applications ,in particular for the rigging of sailing ships.A decline in its use during the 20th century led to a sharp decrease in its cultivation worldwide.Hemp cultivation in Europe rose from 15,000 ha in 2013 to 47,000 ha in 2016,of which 16,400 ha in France.A study conducted by FRD and whose results were published in an ADEME report showed that 200,000 ha of hemp is likely to be cultivated in France in the future for different end uses such as fibre,cannabidiol ,shives for building,but this work only investigates the production of long line fibres.

Indeed,unlike flax,hemp is adapted to the climatic and soil conditions of most areas of France and Europe,which allows its establishment over a large geographical area in Europe or in many places in the world such as China.However,the possibility to perform dew retting advantageously is more favourably conducted in mild and humid areas even though it was shown it can be conducted in many different European climates with increased durations for example.The textile flax production zones in Europe where the extraction capacity by scutching/hackling is already present corresponds to the most favourable zone for dew retting of flax and also for hemp.Hemp could also be favourably inserted within flax crop rotations due to its limited fertilizer and pesticide requirements and for its competition against weeds.In the 19th century,harvesting was performed mainly by hand in Europe and in China.In Europe,the first machines to perform fibre extraction using breaking rollers and beaters appeared in 1820.In Eastern Europe,hemp was mainly cultivated for textiles for its long line fibres and countries such as Hungary and Romania developed specific scutching and hackling devices to extract the fibres.These machines,however,required as input,well-retted stems.Water retting was traditionally performed prior to fibre extraction.These processing lines could process whole hemp stalks and very long line scutched fibres could be obtained.However,the resulting fibres were subsequently cut into sections of about 70 cm to be hackled on flax machines.These devices are now very old and have been decommissioned for their dependency on water retting that has been banned in most countries due to its high environmental impact and the risk for humans and animals health.Moreover,the hemp industry in Eastern Europe was labour-intensive,particularly for the harvesting stages and this negatively affects the economic sustainability of traditional value chains.Indeed,the hemp sector has not been able to draw inspiration from the mechanisation of the flax sector and there is currently no complete mechanised hemp harvesting chain for long line hemp fibre production.China,for its part,has invested considerable resources to modernise and recreate an economic sector entirely based on the flax value chain and field retting.This means using flax machinery for the management of the harvesting and fibre extraction.However,this requires that the stem length is shorter than 1 m.In the field a hemp mower,grow lights for cannabis a swath turning machine to homogenise the field retting and an adapted baling system are necessary.

A similar production system proved to be technically feasible in the early years 2000 with the “baby hemp” cultivation in Italy ,where stems were kept short by applying an herbicide when the plant was approximately 120 cm high.In China,manual labour is still used to perform dew retting management and cutting hemp stems in 1 m pieces.If in the past,the numerous attempts to develop hemp harvesters were not completely satisfactory ,suitable hemp mowers are now on the market.However,a machine to cut on the field the mown stems is still not available but this is necessary if flax turning and bailing machinery is to be used.This type of machine is under study and advanced prototypes were tested in summer 2021 with a global success even though improvements need to be completed.With the success of such a prototype,a complete value chain could be created using flax processing lines.Nowadays,hemp fibres for paper pulp,or insulation materials are extracted using hammer mills.This process is very efficient but it damages the fibre and reduces its length.Hemp fibre price,used for technical non-structural automotive applications,is generally much lower than the price of scutched textile flax.However,the mechanical properties of hemp fibres extracted using a hammer mill remain generally low.These fibres cannot be used for load-bearing applications.The possibility to obtain load-bearing grade fibres from hemp would open a complementary market to the one of flax fibres,which is globally saturated and guarantee a higher price than that for the fibres extracted using hammer mills.Ideally,this price should be lower than that of flax long line textile fibres,too expensive for numerous applications in the automotive or other industries.As mentioned above,the old East European hemp scutching and hackling lines are no longer operating,and only flax dedicated equipment are available industrially to extract long line fibres.Preliminary scutching and hackling trials of hemp stems on industrial flax lines were performed by with low scutching yields of long line fibres and high amounts of scutching tows.Vandepitte et al.also used industrial scutching facilities with some of the process parameters changed for hemp extraction purposes with a wide range of European hemp varieties.Higher levels of long fibre scutching yields were globally obtained but this one was dependant on the batches/varieties/levels of dew retting.Following scutching,hackling is generally performed to start the division of technical fibres.During this process tows may also be generated.In hemp stems,the mass of fibres represents,depending on the varieties,about 30–35 % of the mass of the stem.To value the hemp straw and particularly its fibres in the most advantageous way,it is essential to maximise the amount of long line fibres obtained at the end of the extraction process.Main objective of this work is to investigate if hemp could become a source of long line fibre for load bearing composites in complement to the flax ones.To reach this objective,this study proposes to study the long fibre yields obtained at the end of the scutching/hackling process and the quality of fibres that can be obtained.

This has implications for the development of multi—purpose cropping systems of hemp.While low quality fibre can be extracted from plants gro̶wn primarily for their seeds or chemicals derived from inflorescences,the extraction of high-quality textile fibres requires harvesting when no seeds or inflorescences are present yet.Fibres from socalled multi—purpose hemp grown for seed and fibres will thus always contain a mixture of short and long fibres.Plants of increasing height and weight in Fig.6 could represent the same plant at different moments in time,but they can also be considered different plants in a crop at the same time,because with respect to primary  and secondary fibre development,individual plant size is the key factor,not the moment a particular height or weight is reached,or the phenological stage.The stem part that is valuable for textiles,the stem part between the dotted lines in Fig.6,is located higher up along the stem with increasing plant size.It is supported by a stem base of increasing length and weight,which is unfit for yarn production due to the presence of secondary fibres.In short plants  a share of the primary fibres,though fit for yarn spinning,is lost in the stubble,which in practice is 15–20 cm.Once the secondary fibre front surpasses the stubble height  part of the primary fibres are contaminated by secondary fibres.The lower in the plant or the heavier the part of the stem above,the thicker this unwanted fibre layer is likely to be.For reasons of simplification,the inflorescences of the plants in Fig.6 have equal lengths for all plants,it could however be expected that this part becomes gradually longer with increasing plant size.However,vertical grow system no data were recorded.

Mediavilla et al. showed in a dioecious variety that the accelerated development of secondary fibres around flowering first takes place in female plants and later in male plants.This makes sense,when the increasing weight is considered the cause of secondary fibre formation.Male plants on average are longer,but the female inflorescences,where the seeds are gradually filled,are likely to have a higher weight.Bócsa and Karus  also stated that female plants have a relatively higher secondary fibre content than male plants.The proposed conceptual model  also implies that homogeneity with respect to plant size is important when growing hemp for textile uses.In stands with plants of different heights the valuable ‘middle section’ is at variable height,which would cause difficulties in harvesting and processing.The tops of the plants are the comparable parts,not the bottom parts.According to both Fig.4  and 5,secondary fibres above stubble height in Futura 75 can be avoided when the crop is cut when plants are around 1.3–1.4 m and not yet flowering.It is likely,however,that this height is different for varieties,as secondary fibre development is reported to be different between varieties.Reported differences,however,could partially be due to size differences as well.For this reason true varietal differences and differences caused by size differences should be disentangled in future experiments.A non–flowering crop with a height of 1.3–1.4 m can be grown in about two months when hemp is sown at a normal sowing date in April under Dutch growing conditions.However,a subsequent second fibre hemp crop,to compensate for the relatively low stem dry matter yield of the short crop,will be a challenge.For a first sown crop,varieties can be chosen based on excellent fibre qualities,for a possible second crop the variety should be late flowering and it should also have an inherently low secondary fibre content.Further the soil has to be prepared into a homogeneous seedbed again and in dry years irrigation might be necessary to achieve even emergence.Due to the drier summers and shorter days a second crop seems less realistic in Italy than in The Netherlands.However,even when technically possible,it should be economically sound as well,which is doubtful as yet.An advantage of a short crop is that the stems could be processed on existing flax  processing lines as the limited market for high‒quality hemp yarns as yet does not justify the development of specialised hemp scutching and hackling lines.Such systems are dimensioned for flax ribbons with a length usually between 80 and 120 cm,which is about the length of the useful middle section of the stems in our experiment.Earlier attempts in Italy to produce smaller hemp plants by stopping their growth with glyphosate at the desired plant height of 1.2 m  failed due to the environmentally unfriendly production methodology,low yields,low quality,and high costs.Westerhuis et al.,however,showed that normal amounts of scutched long fibres can be extracted from smaller plants.However,these fibres were not hackled.It is likely that the early harvested short crop that we need to avoid secondary fibre formation has relatively fine primary fibres as well.

Fibres have been reported to be finer with decreasing plant size or conditions that in general cause smaller plants,e.g.,earlier harvest or increasing sowing density.Also with respect to the unwanted lignification of the fibres an early harvest before flowering seems best.For future research on this topic it has to be considered that between individual plants of the same height or weight relatively large differences exist in the height of the secondary fibre front.This was not only caused by the fact we measured once every 10 cm stem length; in the field experiment where three cuts were made in every internode a comparable spread was observed.Differences between plants  and,e.g.,wind would co-determine the actual forces  along the stem and thus the mechano perception  inducing fibre formation.Further,we should keep in mind that countering the forces the plant is subjected to,means countering the fresh weight,not the dry weight we measured hence plant fresh weight should be measured as well.To study the effect of weight on secondary fibre formation in more detail,plant weight could be increased artificially.Cannabis sativa L. has been used for more than 6000 years as a source of food, fiber, oil and medicine, as well as for recreational or religious purposes . Cannabis has a very complex chemical composition, with around 540 reported specialized metabolites, such as cannabinoids, terpenoids, flavonoids and alkaloids. The most active of these are by far the cannabinoids, a class represented by more than 100 known terpenophenolic compounds that accumulate mainly in the resin secreted from the trichomes of female plants . Based on its use, cannabis can be technically divided into two distinct groups: marijuana and hemp. Traditionally, marijuana is almost exclusively grown in greenhouses or other controlled environment facilities, being primarily bred for its main psychoactive cannabinoid, Δ9 -tetrahydrocannabinol . On the other hand, hemp serves more as an agricultural commodity, being valued for its fibers and seeds and, more recently, for its nonintoxicating medicinal compounds, notably cannabidiol . From a legal point of view, in most European and North American countries, cannabis is classified as hemp if the crop contains less than 0.2−0.3% THC . Due to their low THC content, hemp and CBD products have recently gained an increased popularity, as their attributed medical benefits are achieved without the “high” effects of marijuana . Consequently, a wide panel of products are nowadays marketed as “full-spectrum” formulas, dietary supplements or CBD-enriched products . The presence of pesticides in hemp crops is a very challenging issue nowadays, not only for cultivators, but also for regulators, consumers or public health researchers .

Many studies have revealed there is no clear relationship between pesticide use and augmentation of cannabis yields, being repeatedly claimed that their role in weed and pest control might be actually unnecessary . Beside their concealed use during cannabis growth, other reasons for pesticide contamination might be related to the spray drift from adjacent crops or assimilation from the contaminated soil; numerous pesticides are environmentally mobile, being carried away by groundwater and rain, whilst cannabis is recognized as a robust and fast growing plant able to absorb pollutants with a great efficiency . Thence, pesticide contamination of cannabis materials has been repeatedly brought into attention . A survey of 389 cannabis products from the state of Oregon found 24 residual pesticides, with piperonyl butoxide as the most commonly retrieved contaminant. Furthermore, 12 pesticides were found in up to 50 % of the cannabis samples collected from central Californian dispensaries . Out of 26 investigated cannabis samples, 84.6 % were confirmed to be positive for pesticides from various classes, such as insecticides, miticides, fungicides or growth regulators . In addition, a multi-screening study testing for 71 residual pesticides in various cannabis products from Italy revealed that amitraz, chlorpyrifos and trifluralin were above the acceptable residual limits set at 0.010 mg/kg . Nevertheless, occupational or non-occupational exposure to residual pesticides has become an important issue due to potential adverse health effects. For example, organophosphate pesticides, mobile grow systems such as chlorpyrifos, malathion, parathion methyl, ethoprophos or coumaphos, have been found to be highly toxic, inducing neurobehavioral and cognitive disorders, teratogenicity, immunotoxicity or endocrinal and metabolic disturbances . Daminozide and paclobutrazol are two plant growth regulators that have been banned in the USA and numerous European countries, due to their carcinogenetic properties; however, both have been found as contaminants in cannabis products . In this light, more and more regulatory agencies are addressing the residual pesticides issue in cannabis products. For example, in the USA, pesticide regulations are specific to each state, mostly due to the fact that cannabis cultivation is still not yet federally legal.

Among the states, California has the most severe requirements, monitoring 66 pesticides, followed by Oregon with 59 pesticides. In comparison to these, Canada has set wider and stricter controls of pesticides in cannabis products, demanding testing for 96 pesticides, with limits of quantification usually lower than those set in the USA . From a processing point of view, cannabis derived extracts are frequently obtained using CO2-supercritical fluid extraction followed by winterization , decarboxylation , distillation and, optionally, a chromatographic-based method for the isolation of specific cannabinoid compounds . For instance, CBD purification is mostly achieved by recrystallization, conventional chromatography with solid stationary phase or liquid-liquid chromatography. LLC, better known as centrifugal partition chromatography and counter current chromatography , is a preparative separation technique where the two phases of a biphasic solvent system are used as the mobile and stationary phase. One of the two phases is kept stationary inside the column with the help of a centrifugal field, while the other one is pumped through the column . In this sense, LLC enables high column loading, while expensive solid stationary phases and time intensive column packing procedures are not required. In addition, the almost limitless variety of possible biphasic solvent systems and easy preparation of tailor-made solvent systems make LLC a very flexible, scalable, as well as selective separation technique . Taking advantage of these benefits, Hazekamp et al. showed that CBD can be separated by CPC using n-hexane/acetone/acetonitrile 5/2/3 as a biphasic solvent system, with the acetonitrile-rich phase as the stationary phase . To this end, a considerable attention has been paid either on the large-scale purification of CBD by LLC or the ultra-trace detection of residual pesticides in cannabis products, but not to the removal of the contaminating pesticides. Therefore, the aim of this study was to establish a systematic computer-aided approach for the selection of biphasic solvent systems for the simultaneous purification of CBD from hemp extracts and removal of specific-contaminating pesticides. In this sense, a predictive thermodynamic model was used for solvent system screening, guiding the user toward the design of tailor-made solvent systems for the isolation of pesticide-free CBD from a particular hemp extract using LLC. Two experimental protocols were followed in the shake-flask experiments, depending on the purpose. For the initial screening of the partition coefficient of CBD in different solvent systems, 5 mg of hemp extract were added to upper and lower phases of preequilibrated solvent systems and placed into a 20 mL vial. Then, each phase was analyzed by HPLC-DAD . Once the three solvent systems were selected, the six pesticide mixes and CBD standards were combined together and a stock solution, in which CBD and each pesticide had a concentration of 50 ppm, was obtained by a proper dilution in acetonitrile. 20 μL of the stock solution were added to 20 mL of each of the three selected solvent systems, affording a nominal concentration of 50 ppb of each solute. Afterwards, 1 mL of upper phase and 1 mL of lower phase were taken, evaporated to dryness, re-dissolved in 1 mL methanol and analyzed by LC–MS/MS to determine the concentration of each analyte in the phases.

These functional properties are the result of the vegetal aggregates employed in the formulation,whilst mechanical strength is provided by the presence of frame.Numerous studies have been carried out on defining and understanding the properties of the material,or optimising the formulations used.A number of recent studies have looked at the durability and long-term behaviour of these insulators,but the accelerated aging processes are much too short or overly severe in comparison to real-world conditions of use,such as the application of freeze–thaw cycles.However,lack of knowledge about the evolution of the properties of plant-based concretes over time is a barrier to the development of these materials.Indeed,the lack of guarantee as to the durability of the desired properties over a given period of time does not inspire confidence in users,architects or insurance companies.It is for these reasons that a study is conducted on the durability of hemp-based concretes,with the aim of identifying the mechanisms which cause the functional properties of the material to change.However,to date,there has been no study done of the change over time observed in the plant aggregates on their own,although it is these particles which are responsible for a large proportion of the properties for which the material is used.In order to understand the mechanisms of aging of plant-based concretes,it seems essential to understand the behaviour of the particles in bulk over time.With a similar chemical composition,made up of cellulose,hemicellulose and lignins for the most part,it is possible to draw inspiration from the numerous studies examining the durability of wood.

Durability studies on wood have produced standards which guarantee quality and users’ expectations over a given period of time,mobile vertical rack in set usage conditions and with an amount of maintenance.Depending on the application,specific wood species are chosen according to the applications and the conditions of use.Various aging factors are applied on wood in these studies,such as immersion in water for periods from 10 days at 60 and 90 °C to 8 and 2000 years in natural conditions,variations of relative humidity during 20 days to one year,exposure to UV aging until four weeks or natural aging without protection during several years.Therefore,depending on the study in question,the aging conditions are very different in terms of environment or exposure duration.Whatever the protocols used,the functional properties are monitored over time,namely mostly mechanical and/or hygroscopic properties,but also acoustic properties.Overall,aging leads to deterioration in the mechanical properties and to an increase in water sorption capacity.Other parameters which characterise the microstructure of the material are also studied,such as porosity,swelling,or variations in weight of the materials.The variations of functional and microstructural properties are often explained by a change in the chemical compositions of the wood,usually due to the degradation of the lignin or hemicellulose.These chemical degradations may result from photo-oxidation or thermo-oxidation reactions,but above all,from the action of micro-organisms which can grow on lignocellulosic materials in high humidity conditions.Indeed,the micro-organisms use the cellulosic materials as a nutrient,and they may,selectively or otherwise,attack pectin,lignins,hemicellulose or cellulose.These micro-organisms are present in the air and in water,but also in the plants as they grow.Indeed,in order to separate the fibres from the stalks more easily,the material may be retted for a time,enabling the micro-organisms to consume the pectin which binds the fibres together.Therefore,such retting impacts upon the properties of the materials.There are various tests of resistance to the growth of micro-organisms,placing the plant materials inoculated with moulds in conditions of high hygrometry,as for example 26 °C and 85 and 95% RH,or 20 °C and 70% RH.

The result of an attack by micro-organisms is a loss of mass of the materials,which can lead to structural alterations which modify the functional properties,such as mechanical properties.In view of these results,three environments are chosen in this study to assess the durability of hemp aggregates used for vegetal concretes.The second one is an accelerated aging imposing variations in humidity.The relative humidity varies from 40% RH to 98% at a fixed temperature of 30 °C.Indeed,in the normal conditions of use of hemp concrete,unlike wood,hemp shiv should never be exposed to direct UV light or to liquid water.This temperature favours the development of microorganisms,which has been identified as a significant degradation factor.Finally,a harsher,outdoor aging process is used.The objective of this article is to identify the mechanism by which hemp shiv ages in the presence of moisture.The potential evolution of the functional properties of the material  is characterised and linked to the micro-structural changes  occurring in the different environments.The acoustic properties are measured using a Kundt tube.Two types of properties are obtained: the acoustic absorption co-efficient α and the transmission loss TL.The acoustic absorption co-efficient is the proportion of sound energy absorbed by a material.It is expressed for values ranging between 1  and 0.The transmission loss  represents the sound insulation provided by a material.3 measurements are taken for each batch of bulk shiv over a frequency range [250–2000 Hz].At A0,the batches contain 40.7 g of hemp shiv,to obtain a controlled density of 130 kg·m−3 in the volume of the sample chamber.The different batches are aged and reused for the acoustic measurements.The hydric behaviour is determined on the basis of the water vapour sorption isotherms using a DVS machine.A few granules representing a few tens of mg are suspended in a microbalance within a sealed thermostatically controlled chamber at 25 °C.The schedule for the DVS is set to start at 0% RH up to 95%.A given relative humidity is applied until the weight change of the sample is less than 0.0005%.min−1 or during 12 h if the weight is not stabilised.Sorption isotherms are produced by plotting mass change against relative humidity  and illustrate the water vapour sorption capacity as a function of the relative humidity.The overall sorption behaviour across the whole range of relative humidity values is simulated using the GAB model,as described in an earlier study.

Depending on the kind of porosity,it may be open and accessible for measurement,open but not accessible to measurement,or closed.With a pore size in the millimetre range,the interparticle porosity,represented in grey in Fig.3,is always open and accessible.On the other hand,the intraparticle porosity may contain closed pores and pores not accessible to the measurement.For simplicity’s sake,no distinction is drawn between intraparticle porosity which is closed or open but not accessible; both are denoted by Φintra_closed.This category is randomly represented in dark green in the diagram.The open and accessible intraparticle porosity is called Φintra_opened.By combining different techniques,it is possible to quantify the different volume fractions corresponding to the vegetal part or to each type of porosity.In all cases,these volume fractions are expressed as a function of a volume of bulk shiv.The bulk density ρ of the hemp shiv is the ratio of the mass of a batch of bulk hemp shiv to the volume it occupies in unstressed conditions.The density of the plant cell wall ρcell wall is an intrinsic value of the material,which depends on its chemical composition.In this case,the vegetal cell wall is expected not to contain any porosity.The volume corresponding to the vegetal cell walls of the material is measured by introducing a fluid into the pores in the material.Knowing the mass of the sample introduced,the density of the vegetal part can then be calculated.To measure this density,the hemp shiv is ground to a powder of grain size less than 500 μm in order to eliminate the porosities of the vegetal cell walls.The volume of the powder is then measured using a helium pycnometer.New energy storage systems have been continuously developed for replacement of fossil fuel to meet global energy requirements in the last decades.Multifunctional materials with an integration of structural and non-structural functions create new areas in the advanced energy storage system,such as structural super capacitor,which can maintain its capacitive function under a mechanical loading.At least two components of structural super capacitor are required to satisfy structural function such as structural electrode and structural electrolyte or separator.Maybe the structural electrolyte is more challenging,because that it must combine high ionic conductivity with good mechanical strength.However,it is generally known thationic conductivity and mechanical performance have an inverse relationship,because ionic conductivity requires pore structure for ion migration but strength needs compact structure.

A bicontinuous structure of electrolyte is designed to keep a good balance of performance,where one phase provides ionic conduction and the other phase is responsible for mechanical properties.The earliest structural electrolyte is polymer resin as structural component and ionic liquid based electrolyte as ionic conductive phase because polymer-based electrolyte has good mechanical properties,long lifetime,short charging time and wide potential window.Generally,polymer resin may contain of epoxy resin with more than two oxirane groups,polyethylene oxide or polyethylene glycon,while ionic liquid phase can combine several types of cations and anions.Shirshova et al.prepared ionic liquid-epoxy resin composites to obtain a structural electrolyte with ionic conductivity of 0.8 mS·cm−1 and a Young’s modulus of 0.2 GPa.Cole et al. reported polymer electrolyte-based stretchable super capacitors with a specific capacitance of 5–10 F·g−1 and mechanical stress of 0–3 MPa in suit microtensile characterization.Greenhalgh et al.fabricated structural super capacitors with epoxy which exhibited a compressive strength of 19.44 MPa and a specific capacitance of 4.5 m F·g−1.A novel structural super capacitor based on ionic liquid-polyester resin had a specific capacitance of 2.48 F·g−1,an equivalent series resistance Rs of 370 Ω and an in-plane shear strength of 102.4 MPa.However,the polymer electrolytes tend to have a low specific capacitance,and as the electrochemical property improves,the mechanical performance typically decreases,vice versa.Thus such polymer electrolyte may not well solve the challenge of balancing the electrochemical and mechanical properties of structural super capacitor.Recently,another kind of structural electrolytes were reported for building applications,cement as structural component and aqueous electrolyte as second phase.Normally cement as gel materials has high mechanical strength as well as prosperous pore structure.The pore size of pore structure can be divided into b20 nm,20–100 nm,100–200 nm and N200 nm,vertical grow rack and the amount of macropores in cement is N90% of total pores.As hydrated radius of aqueous electrolyte is generally smaller than 0.5 nm,such pore structure in cement is large enough to be filled with aqueous electrolyte to form structural electrolyte as well as to provide channels for ions passing,which is similar to the effect of pore size on the performance of electrodes.Zhang et al.reported a cement-based structural electrolyte with a specific capacitance of 10 F·g−1 and a compressive strength of 9.85 MPa.

Subsequently,Xu et al.fabricated a structural electrolyte based on geopolymer with a compressive strength of 33.85 MPa and a specific capacitance of 33.4 F·g−1.Ma et al.also reported a combining magnesium phosphate electrolyte with a compressive strength of 24.5 MPa and a specific capacitance of 40.9 F·g−1.Therefore,combining cement with aqueous electrolyte is a promising approach to develop structural electrolyte due to its low cost,structural integrity,chemical stability and good compatibility with structural component.Thus pore structure has an important role in the performance of cement-based structural electrolyte.The porosity and pore inter connectivity are likely to play critical roles in characterizing the pore structure of the structural electrolyte.Hemp fiber has been chosen to alter pore structure of cement based structural electrolyte in this work.There are two reasons for choosing the hemp fiber as pore forming agent.The first reason is that unique interconnected partially graphitic carbon nanosheets with significant volume fraction of mesoporosity has been created from hemp fiber,which exhibits excellent electrochemical performance in super capacitor and sodium ion battery.The other reason is that a large content of hemp fiber often leads to considerable number of macropores,which can result in forming interconnected pore structure in cement.Thus the effect of pore structure of structural electrolyte on the performance of structural super capacitor was investigated by adding various volume fractions of hemp fiber in this work.Typical SEM image of the structural electrolyte containing 15 vol% of hemp fiber is shown in Fig.3a and the corresponding EDX analysis result is listed in Fig.3d.It is clearly seen that hemp fiber is nonuniformly distributed in the matrix due to the large fiber content and non-homogeneous mix.Due to the presence of hemp fiber seriously interfering with image processing,careful selections of parts of SEM images without hemp fiber were used to measure the two parameters of pore structure,including porosity and pore connectivity,like Fig.3b.Image analysis technique is employed to process the SEM images to quantitatively characterize pore structure of the structural electrolyte with hemp fiber,like Fig.3c.

The wett ability of the surface is controlled by the surface chemical composition as well as by the morphology of the mic-structure.Surfaces with a similar chemical composition may have different wett ability behaviour due to the surface topology.In this study,the surface of hemp shiv underwent micro-structural changes via deposition of an organo-functionalised silica coating.Ethanol diluted sol series enhanced the surface roughness of the hemp shiv.At higher HDTMS loading,undiluted coatings  lowered the surface roughness of the shiv which could explain the reason for lower contact angles compared to diluted coatings.Sol A-1 and sol A-5 have HDTMS molecules that are not fully hydrolysed and being deposited onto the membrane as a flat thick film as seen in Fig.6b.The reduced surface roughness can be attributed to the extra HDTMS molecules on the coated surface.Since an organic-inorganic hybrid coating was used,the ratio of TEOS: HDTMS was critical to control the roughness of the coatings resulting in variable water repellent properties of the coated hemp shiv.Most of the coatings enhanced the surface roughness except sol A-1 and sol A-5.These coatings had smooth surfaces with cracks which could explain the lower contact angles even though it had the highest loading of hydrophobic agent.It was observed that the TEOS: HDTMS molar ratio in the coating formulations affected the hydrophobicity of the coated hemp shiv.From Fig.3 it can be seen that varying the concentration of HDTMS in the formulations affects the water contact angle.When TEOS: HDTMS was 1: 0.01 corresponding to 0.5 wt% HDTMS,the contact angle was below 100◦ which suggests the concentration of the hydrophobic agent was too low to provide sufficient level of hydrophobicity.

The best results were obtained with TEOS: HDTMS ratio 1: 0.02  with contact angles up to 118◦.However,when the TEOS: HDTMS ratio was increased to 1: 0.06,the hydrophobicity was decreased for the undiluted sol coatings.These results can be explained by the combined effect of surface roughness and energy.TEOS is hydrophilic whereas HDTMS is hydrophobic and changing their molar ratio can affect the surface roughness and energy ofthe coated material.Increasing the HDTMS concentration would reduce the surface energy.However,best trimming trays the surface roughness can be reduced if the HDTMS concentration is high enough as the extra silane fills the inter-particle gap.Similar results have been reported in different coating systems.Although sol B-7 coating enhanced the surface roughness,it had developed cracks which lowered the water contact angle to 98◦.The presence of surface cracks arising as a result of shrinkage after drying the coated shiv is a significant factor to be considered when hydrophobic properties are concerned.The hydrophobicity of modified hemp shiv can be compromised as the water molecules can penetrate through the cracked coating wetting the bulk of the material over time.Therefore,sol-gel coatings chemically modified the surface of hemp shiv which overall improved the hydrophobicity of the material.The high water repellence can be attributed to the long alkyl chains of HDTMS that provide high hydrophobicity.The chemical composition of hemp shiv is mainly composed of cellulose,hemicellulose and lignin,which altogether contain a large percentage of oxidized carbon in their structure.Hydroxyl groups are known to contribute towards majority of the carbon-oxygen bonds in bio-based materials.The XPS data confirmed that the sol-gel deposition on hemp shiv significantly altered the surface chemistry.The surface carbon content of the coated hemp shiv decreased by 41.28%.On the other hand,the oxygen content increased by 26.51%.

This change in C/O ratio and increase in surface oxygen concentration can be attributed to O CH3 bonds present in the polysiloxane coating on the surface of the sol-gel coated hemp shiv.Moreover,the decrease in the surface carbon concentration of the sol-gel coated shiv can be attributed to the masking effect of the polysiloxane coating which reduces the detectability of surface cellulose and hemicellulose.The C1s high resolution XPS spectra indicate that the surface has been modified by the silica based coating that led to disappearance of C3 and C4 components of the C1s peaks.A shift in the binding energy of C2 component  was observed along with the decrease in the intensity ofthe C2 componentfor the sol-gel coated sample.This shift indicates the presence of a carbon atom linked to an oxygen and silicon atom.It has also been shown that curing above room temperature drives the dehydration reaction at the adsorption sites between hydroxyl groups of the cellulose and the silanols forming Si O C bonds.These bonds are formed by the linkage between polysilanol network with the cellulose hydroxyl groups via polycondensation as illustrated in Fig.9.The increase in the intensity of C1 component for sol-gel coated sample from 48.01% to 91.09% indicates the presence of C H and C C bonds from the HDTMS hydrocarbon chain.Hemp concretes are the most widely used biobased concretes in France.As an example,VICAT,one of the European leaders in the production of building materials,has developed a construction system composed of hemp shiv and Natural Prompt Cement.Although construction rules exist for these materials,their growth is still limited by the lack of knowledge and high variability of the performances of biobased concretes,especially for their mechanical properties.In addition,even if it is not the main performance expected,they still require sufficient mechanical resistance to be unmolded,transported onsite,and handled.Several parameters,such as setting delays of the binder or potential degradation of plant particles have been identified to explain their mechanical weakness.

Moreover,on existing buildings,problems of powdering of the materials in the core have been observed even when using binder/vegetal couples validated by the construction rules.Currently,while cementitious binders are well characterized,the physico-chemical mechanisms that affect the setting of the binder in biobased concretes have not yet been well understood so far.The modification of the hydration of the binder is related to the extraction of compounds from the plant aggregates which are not chemically inert,contrary to the mineral aggregates of conventional concretes.As a consequence,empirical testing is currently used to assess the compatibility of specific biomass particles and binders couples.These tests validate the performance of a biomass batch and binder couple at a given time,but do not consider the important variability of plant chemical composition and micro-structure.The latter depends for example on plant species,genetic material  and environment of its growth,but also on their transformation process.This lack of knowledge about the robustness and performance of plant-based concretes is the main obstacle to their development.Hemp crete offers a means of achieving the rules set by the French national environmental regulations,which applies since 2022,but also of improving technical aspects of the concrete used in construction today.When dry,hemp has a very low bulk density of around 110 kg.m− 3,meaning that hemp-based concrete is lightweight.It is an effective insulation material with good hygrothermal and acoustic properties.It has low thermal conductivity  due to its porosity and low density.That porosity and the hydrophilicity of hemp create a buffering effect that regulates the humidity within the concrete.Hemp crete is also interesting from an ecological point of view,as it requires no pesticides and cleans the soil,leaving it in a better state than before.Furthermore,it reduces the distance and time of transport from the source to the building site since it uses materials cultivated locally.Finally,the plant particles in the hemp concrete act as a CO2 trap during the lifetime of a building.

Existing studies on bio-based concretes formulated with mineral binders and vegetal aggregates from different origins and chemical compositions showed that the properties of materials are disparate.As an example,for identical formulations,the use of nine types of hemp shiv from different sources leads to differences in compression strength by a factor of 5,while the impact on thermal conductivity is smaller.These results are attributed to the particle size distribution of the bio-resources,their water absorption and chemical composition and to the lixiviation of vegetal compounds.About impact of vegetal components on the hydration of binders,some studies highlight the modification of the mechanisms and kinetics of hydration of mineral binders by vegetal components.Indeed,during the processing of plant-based concretes,vegetal compounds,such as polysaccharides and polyphenols extracted in the fresh concrete mixture,interact with the mineral phases.Some of these extracted compounds can slow down or even completely inhibit the setting of the binders.These results,observed with various vegetal concrete formulations containing wood,hemp,miscanthus,corn or sunflower,depend on the selected plant-mineral binder couple.A correlation can be drawn between the biochemical nature of raw plant materials,including the plant cell wall quality,the composition of the leachates,and the mechanical properties of bio-based concretes.On a different scale of analysis,an interfacial transition zone  is observed around the vegetal particles.The ITZ is a gradual transition region where the composition and micro-structure of the binder matrix are affected by the presence of the aggregate particles.This impacts on the physical properties,mechanical properties,functional properties  and durability  of vegetal concretes.In this study,a newly implemented protocol is set up using a hemp pellet put into a cement paste.The halo of less hydrated material created around this pellet is monitored using image analysis.Different analysis methods  have been used to characterize the hemp crushed for the pellet and to analyze the ITZ and the hydrated matrix.The cement used to make up the cement paste is a Portland cement CEM I 52.2 R,trimming tray kept at a temperature of 20 ◦C in a sealed plastic bag.To reduce bleeding in the cement paste,KELCO-CRETE DG-F from BASF  was used.This is a water-soluble biopolymer used in hydraulic cementious systems as a viscosity modifying agent.The characterizations of hemp were performed on sample dried at 50 ◦C for at least 2 days,in accordance with the RILEM recommendations.The hemp used for the experiments has a bulk density of 116 kg.m− 3.Its particle size distribution is extremely heterogeneous and the initial rate of absorption  is 135 %.

A ThermoFisher Scientific iS50 device with Attenuated Total Reflection  mode was used for Fourier transform infrared spectroscopy measurements.The spectra were acquired from 500 to 4000 cm− 1,with a digital step of 0.5 cm− 1  and on average,with 32 successive scans.Spectra were corrected between 1900 and 2400 cm− 1 to remove CO2 contribution,with an automatic baseline.The data were processed using OMNIC® software.It was decided to differentiate the internal face  from the external face  of the shiv to see its influence.X-ray diffraction  analysis was performed on a Brüker D8 Advance device directly on a pellet of constant size,which was made of 0.1 g of hemp ground and compressed at a pressure of 10 tons.After drying at 50 ◦C,the pellet was removed from the oven and tested as soon as possible  to reduce the impact of water absorption due to air exposure,which can affect the results.The data were analyzed using Specta Software.In order to study the ITZ between the hemp and the binder,the experiments were conducted on hemp pellets in contact with cement paste.The protocol was adapted and improved to tackle the issues encountered in previous studies like robustness,repeatability and accuracy,to monitor the formation of the ITZ from the moment the binder is finished being poured.The compositions of the cement pastes used in this study are presented in Table 1.The overnight data acquisition showed the formation of the ITZ.First,the pellet absorbs the water in the cement paste.Then it begins to dry,and the ITZ forms from its outer edges after approximately 5 h.The cement paste slowly becomes lighter in the vicinity of the pellet.The extracts of hemp seem to be released as soon as the pellet is placed into the cement paste,and percolate around the pellet over a distance of few millimeters.Then,the paste begins to set from the edges of the mold to the pellet,and the halo appears due to the presence of chemical components which delay or interfere with the setting.FTIR spectra of cement  show that while similarities can be found between the ITZ and the hydrated matrix in terms of the micro-structural composition,like the presence of portlandite and O–H bending in cement hydrates,certain components are also in common with the anhydrous cement,like the presence of gypsum,alite,belite,and anhydrite.FTIR mapping shows the evolution of the area under the band relative to portlandite at 3640 cm− 1,with a base line from 3660 to 3600 cm− 1.Portlandite is chosen because it partially reflects the hydration of the cement.The color scale of the mapping ranges from blue,showing a very small vibration band area,through green,to red,highlighting a larger vibration band area.The lower part of the map corresponds to the area near the hemp pellet,as evidenced by the observation.

In order to monitor the effects of reformulation and heating treatment on the lipid oxidation of beef burgers, lipid oxidation was measured in all samples, before and after cooking.Significant differences  were obtained with the addition of GEs, in both raw and cooked samples.In raw samples, burgers reformulated with chia oil  registered higher TBARS values  than the control sample, being burgers with the highest replacement level  which showed the highest  TBARs values.In fact, BCh50 samples showed 3.5 times more oxidation than the control sample.Burgers reformulated with GE with hemp oil  showed similar TBARs values   than control.This fact was in concordance with several authors who reported that the use of GE elaborated with vegetable oils as animal fat replacement in meat products might be complex due to the high oxidation susceptibility of these unsaturated oils.The differences in the lipid profile of the oils, the content of polyunsaturated fatty acids, and the temperature used to generate oleogels or gelled emulsions could affect the MDA levels.It must be noticed that TBARS values in burgers reformulated with GE elaborated with amaranth flour and hemp oil  as well as the burgers reformulated  with GE elaborated chia oil  were below the malonaldehyde limit for acceptability reported by Trindade, Mancini-Filho, and Villavicencio   for loss of sensory attributes and perception of oxidation by consumers.However, it is important to highlight that cooked burgers reformulated with GE elaborated with amaranth flour and chia oil showed values above the threshold limit for consumer acceptability.The influence of the addition of GEs on sensory attributes of raw beef burgers is shown in Table 8.Relevant parameters affecting consumer purchase were measured, such as “color”, “rancid aroma” and “product appearance”.

Panelists did not detect differences between control and reformulated burgers  for any of the three evaluated parameters.This result agreed with the instrumental color parameters,hydroponic grow tent where L*, b* and h* values had no differences  between samples and the rest of color parameters  showed small differences which were statistically significant but without practical significance.In the case of cooked samples, juiciness, chewiness, fat sensation, graininess and general acceptability were evaluated.The only attribute that showed differences  between samples was graininess: BCh25 and BH25 showed the highest  score  without statistical differences between them , while control sample had the lowest.These results agreed with the instrumental analysis since textural analysis revealed only differences in cohesiveness between some samples.For the preference test, control sample  and BH50  were the most chosen.It has to be mentioned that the information about the nutritional improvement  achieved in reformulated burgers was not communicated to panellists and that could be relevant and affect their sensory attractiveness.Hemp  is a widespread herbaceous plant native from Central Asia that belongs to the Cannabaceae family.This plant could be considered as one of the first crops because it is thought that it was cultivated in China 8500 years ago.Hemp has been traditionally cultivated with industrial, medicinal and food purposes.Its fibre was obtained from stems, specifically from the phloem, and it has been widely used, especially in the shipbuilding industry.Female flowers were useful because of their pharmacological properties, and seeds were used mainly as food.Hemp phytochemistry is quite complex and cannabinoids are its most distinctive compounds.They are produced almost entirely in glandular trichomes, which are commonly located in the bracts of female flowers.Nevertheless, other parts of the plant, such as seeds, could contain a small quantity of cannabinoids , which is subject of regulation in different countries of the world.

The most important one is Δ9 -tetrahydrocannabinol , due to its psychoactive properties, and only varieties with low Δ9 -THC content can be cultivated.Nowadays, the consumption of hemp seeds and derivative products is increasing.Whole hemp seeds are used as a raw material, but could be consumed as food as well, and hulled hemp seeds are commonly marketed as functional food.Hemp seeds contain large amounts of fibre, fat, and protein, at 27–40, 25–35, and 18–28 g/100 g, respectively.They contain significant amounts of linoleic acid, which represents 50% of total fatty acids, 16–19% of α-linolenic acid, 12–17% of oleic acid, and other minor fatty acids, being remarkable the presence of γ-linolenic acid.In addition to nutrients, hemp seeds contain bio-active compounds which confer a biological potential, such as antioxidant, antimicrobial and cytotoxic properties.Chen et al. attribute some of these bio-active properties to phenolic compounds, the main being lignanamides, such as cannabisins.The studies about mineral elements in hemp seeds are scarce, but Callaway  and Mihoc et al. reported an interesting content of some of them, such as phosphorus, potassium, magnesium, calcium, iron, zinc, manganese, and copper, which are essential dietary elements for mammals and are involved in many physiological processes.Mineral element bioavailability could be compromised by different anti-nutrient components in foods, such as phytates and oxalates, which are present in hemp seeds.Phytic acid is the main storage form of phosphorus in seeds and it can form insoluble complexes with some cations, such as calcium, magnesium, iron, and zinc.The chelating capacity of phytates is especially damaging in the case of iron and zinc, and their deficiencies constitute a significant public health problem.The absorption of calcium of plant origin is impaired by the presence of oxalic acid, which promotes the formation of insoluble calcium oxalates.The objectives of this study were to determine the mineral element content of different varieties of whole hemp seeds and commercial hulled hemp seeds, as well as the phytate content, which is closely related to the mineral element bio-accessibility.Phytates were determined by an indirect iron  complexometry with sulfosalicylic acid like an indicator of the titration endpoint, according to Romero–Aguilera et al..The extraction was carried out under magnetic agitation for 90 min from 2 g of sample with 40 ml of HCl 0.4 M, which contained Na2SO4 5%.

The resulting suspension was centrifuged at 1890g during 8 min, and the supernatant was filtered and made up to 50 ml with the extraction solution.After that, 20 ml of the extraction solution, 20 ml of FeCl3 0.02 M , and 20 ml of sulfosalicylic acid 20%  were added to 25 ml of the extract, and the mixture was made up to 100 ml with distilled water.Blank was prepared in the same way, but 25 ml of the extraction solution were used instead of the extract.The solutions were heated for 15 min in a boiling water bath and then they were cooled in an ice bath.One aliquot of 20 ml was pipetted together with 200 ml of distilled water and 1.5 g of glycine were added.This solution was heated at 70 ◦C and titrated with EDTA 10 mM while still warm until the solution turned yellow.All the volumes obtained from the titration of the samples and standards were subtracted from the blank value, obtaining the amount of EDTA equivalent to the complexing activity of.the phytates in the sample.For quantification purposes, a calibration curve was built using a commercial phytic acid standard.The analyses were performed in triplicate and the results were expressed as g of phytic acid equivalents /100 g.The results of mineral element analysis of both whole and hulled hemp seeds are shown in Table 2.Regarding macroelements, sodium was the least abundant, with an average value of 2.75 and 1.41 mg/100 g in whole and hulled hemp seeds, respectively.All the samples contained less than 5 mg/100 g.On the other hand, phosphorus was most abundant one, with an average value of 871.2 and 1099.5 mg/100 g in whole and hulled hemp seeds, respectively.Phosphorus content was lower in whole hemp seeds, being the maximum value 928.1 mg/100 g, which corresponded to ‘Tiborszallasi’ variety.Potassium content was also high in hemp seeds, especially in hulled seeds, which contained on average 919.5 mg/100 g, while the average content in whole hemp seeds was 569.6 mg/100 g.Potassium ranges were wide, from 311.5 to 713.6 mg/100 g in whole hemp seeds and from 778.8 to 1067.7 mg/100 g in hulled hemp seeds.Magnesium content was also higher in hulled hemp seeds, in which ranged from 482.3 to 934.2 mg/100 g, with an average value of 696.9 mg/100 g.However, cheap grow tents the range in whole hemp seeds was very narrow and there were not statistically significant differences between the eight analysed varieties.The average magnesium content in whole hemp seeds was 383.4 mg/100 g.Calcium content, on the contrary, was higher in whole seeds, with an average value of 175.6 mg/100 g, being half in hulled hemp seeds.

In respect to microelements, most of them were more abundant in whole seeds.Iron was the major microelement in whole hemp seeds, with an average content of 8.04 mg/100 g, closely followed by zinc and manganese, whose average contents were 7.94 and 7.48 mg/100 g, respectively.Zinc was the most abundant microelement in hulled hemp seeds, with an average content of 9.81 mg/100 g.Iron content in hulled hemp seeds were slightly lower than in whole seeds, 7.83 mg/100 g, while manganese content was much lower, 5.18 mg/100 g.Copper content was lower than the other microelements, on average, 2.30 and 1.48 mg/100 g in whole and hulled hemp seeds, respectively.Among the analysed varieties, ‘Carmagnola’ variety stood out because it had the maximum values of sodium, calcium, manganese, iron, and zinc, and the minimum values of magnesium and phosphorus, and the ‘Kompolti’ variety stood out because it had the maximum values of potassium and copper, and the minimum values of calcium, manganese, and iron.Regarding hulled hemp seeds, there were a wide variation among the different brands.As it has been said previously, few studies on mineral elements in whole hemp seeds are available, so it is difficult to compare these results with previous studies.Callaway  reported the contents of mineral elements of the ‘Finola’ variety, which was not analysed in this study, and Mihoc et al. studied five different Romanian varieties that were not analysed in this work either.The sodium content reported by Callaway  was slightly higher, 12 mg/100 g, while all the varieties analysed in this work had sodium content lower than 5 mg/100 g , but its content was much lower than the other macroelements in both cases.That study also reported higher potassium content , closer to hulled hemp seeds than to whole seeds.Mihoc et al. obtained a wide range for this mineral element, from 569.3 to 1889.7 mg/100 g, on average.Two of those varieties had potassiumcontents within the range of this study , but the other three had much higher content.Calcium values reported by Mihoc et al. were close to those of this work , except one of the varieties, which had a content three times higher than the maximum value.The magnesium content range reported by Mihoc et al. included all the values obtained in this work, and Callaway  indicated a higher value, 483 mg/100 g, but close to the maximum obtained in this work.According to Callaway , phosphorus was the most abundant mineral element, but the value was higher, 1160 mg/100 g, closer to phosphorus content in hulled hemp seeds, which were higher than 1000 mg/100 g in every sample.Iron content reported by Callaway  was slightly higher than those of this work, 14 mg/100 g, but the values reported by Mihoc et al. were higher than 160 mg/100 g, 20 times the average value in whole hemp seeds.Manganese, copper, and zinc content data were consistent to those reported by Callaway  and Mihoc et al..

The only literature source of mineral element content data in hulled hemp seeds is the FoodData Central.Sodium, magnesium, calcium, iron, manganese, copper, and zinc values included in the database were close to those of this work, while potassium and phosphorus values, 1200 and 1650 mg/100 g, respectively, were higher than the maximum values obtained in this work.Considering the nutrient reference values  of mineral elements established by the European Union , Fig.1a represents the percentage that 100 g of whole and hulled hemp seeds contribute to those NRVs, while Fig.1b represents the contribution percentages of 30 g, which is the serving size.As it can be seen in Fig.1a, and according to European Union regulation on nutritional claims made in foods, both whole and hulled hemp seeds could be considered high in magnesium, phosphorus, manganese, copper, and zinc because their contributions were higher than 30% of NRVs.The contribution of whole hemp seeds to potassium NRV was slightly lower than 30%, so they could be considered as a source of potassium , while hulled hemp seeds could be considered, high in potassium.Whole, but not hulled hemp seeds, could be considered a source of calcium.

Among hemp samples, Hemp 5 displayed the highest WHC and HWHC, which could be attributed to its higher protein content and denaturation/aggregation occurring during its double AE-IP. In fact, Hadnađev et al.  showed that AE-IP hemp protein showed a two-fold higher WHC than their counterparts obtained through micellisation. On the contrary, it seems that pea protein lost its ability to hold water upon heating likely due to the exposure of more hydrophobic groups on the protein surface.This process occurs upon heating and subsequent cooling of a concentrated protein solution. In fact, to create a heat-set gel, proteins should be unfolded upon heating so that both polar and non-polar residues are exposed and able to form hydrogen bonds and hydrophobic interactions during the cooling process. In this process, the rate of protein aggregation and network formation is higher than that of unfolding . Therefore, proteins with a high number of non-polar residues can form the network faster . In this respect, Hemp 2, with the highest H0, exhibited the lowest LGC . Meanwhile, Hemp 5, despite having the highest protein content among hemp samples, showed one of the highest LGC, which could be explained by its significant denaturation/aggregation . The low LGC of Hemp 1 could be explained by its highest content of carbohydrates , sub irrigation cannabis which could have hindered its ability to form a stable gel at lower concentrations. HMMAs were made considering Hemp 3 and Hemp 5 samples as representatives for dry- and wet-fractionated hemp protein samples, respectively.

Low-field nuclear magnetic resonance  has been recently utilized as a fast and non-destructive method to study the distribution and mobility of water in food matrices such as meat and meat analogues . In this technique, a sample is subjected to radio frequency pulses inside a magnetic field and the water or lipid state in the sample can be assessed based on the relaxation time  of proton nuclei of water molecules . The relaxation time of the protons indicates how tightly  or loosely  water molecules  are bounded to the solid phase of the matrix. In general, an NMR decay curve can be fitted to three or more exponentially decaying compartments , showing the water distribution in the sample. Accordingly, a relaxation time curve provides two different parameters for the water state in a food matrix, namely water mobility  and the amount of water distributed within each mobility component . Fig. 5 shows the T2 relaxation time curve for pea, Hemp 3, and Hemp 5 HMMAs, and four distinct peaks roughly centred at 1–2 ms , 10–14 ms , 45–50 ms , and 138–220 ms  were observed. The first water population with the lowest relaxation time  reflects those water molecules closely bound to proteins or polysaccharide molecules . In this respect, Hemp 3 extrudate displayed the lowest absolute area in this region probably due to the higher number of hydrophobic patches, i.e., higher surface hydrophobicity , which could expel water upon protein structuring on fibrous structures. The second two compartments, T21 and T22, represent the immobilized water entrapped in protein or polysaccharide gel structures. As can be seen in Fig. 5 and Table 4, pea extrudate had the highest absolute area in T21 and a small peak in T22. This occurrence indicates that most of the water in this sample is entrapped in a protein network, as opposed to being immobilized in a polysaccharide network, which is consistent with the fact that pea displayed the highest amount of protein  and the lowest amount of TDF . Hemp HMMAs, with lower protein and higher carbohydrate contents, showed shorter relaxation time  and higher absolutes areas of T22 peaks than pea, respectively , indicating more water being entrapped by the polysaccharides.

It is noteworthy that the main peak T21 is sensitive to the homogeneity of the water in the samples , increasing its susceptibility to become broader in compositionally heterogeneous samples . As an example, Aursand, Gallart-Jornet, Erikson, Axelson, and Rustad  observed that the addition of salt to cod and salmon meat leads to peak broadening due to the salt hydration effect. This occurrence would explain the T21 peak broadening of Hemp 3 and Hemp 5, which possessed more ash, lipids, and TDF than pea . Lastly, the third region of relaxation time curve  reflects the free water in the system, which is the fraction that can be lost upon the cooking process of meat. Typically, this water population appears above 100 ms in an animal meat system . Thus, the longer relaxation time of T23 region shown for the HMMAs indicates that water is more prone to leave the plant protein structure, which more closely resembles the process that occurs in animal meat. In this regard, Hemp 3 HMMA would be the best choice from a free water standpoint, since it had the highest absolute area in this region, followed by Hemp 5 and pea . Tensile and small amplitude oscillatory rheological experiments were performed to evaluate the mechanical properties of the plant-based HMMAs and their relationship to their visual appearance and water mobility. HMMA made with hemp exhibited a remarkably greater fibrousness, following the order of EHemp5> EHemp3 >EPea . It was also observed that the extrudates made of EHemp5 presented longer and more defined fibres that the EHemp 3 counterpart. Meanwhile, EPea exhibited a more isotropic structure, where fibres were hardly visible. The visual appearance of the samples was in agreement with the tensile tests performed parallel and perpendicular to the fibre direction, which highlighted a significantly higher anisotropic index for EHemp5 . It is noted, however, that higher anisotropy also resulted in higher sample hardness .

We note that the significantly higher proportion of less interacting water protons with macromolecules of EHemp5 compared to EPea could suggest that the marked phase separation leading to fibrous-like structures could also result in higher proportions of free water . EHemp3 did not follow this rule, which could be likely attributed to peak broadening during LFNMR analysis. Thus, fibrousness, hardness and water mobility should be jointly considered when designing fibrous HMMA. The comparison between SDS-PAGE at reducing and at non-reducing conditions of hemp HMMAs revealed some bands representing edestin that were only present using DTT, in contrast to EPea, whose bands were less intense both with and without DTT. This provides evidence of the higher contribution of S–S bonds in hemp protein aggregation during extrusion than in pea protein. This occurrence aligns with previous reports showing the relative importance of physical and covalent interactions between plant proteins, where S–S bonds were key for anisotropy formation using gluten , and non-hydrophobic and ionic interactions were the main contributors of gel strength using pea . Due to the protein unfolding occurring during extrusion, the hidden non-polar and sulfhydryl groups are exposed to the surrounding aqueous phase. This phenomenon might cause the formation of new assemblies via non-covalent interactions  and disulphide bonds . Hemp protein is richer in sulphur containing amino acids  than pea , which suggests the higher contribution of S–S bonds to form anisotropic structures under laminar flow during cooling of Hemp 5, and could also explain the higher anisotropy of EHemp5, followed by EHemp 3 and EPea. Another explanation could be given by the higher surface hydrophobicity of hemp protein concentrates than the pea counterpart . The combination of highly hydrophobic hemp proteins with the hydrophilic maize starch could have promoted the formation of an optimal multiphasic system during extrusion, where the dispersed phase could have been elongated under tensile and shear stresses into visible fibres in the cooling die. This colloidal approach has been suggested before , although the relative importance of the molecular model  and the colloidal approach are still the subject of debate. The differences in the fibre-forming ability between EHemp3 and EHemp5 should be ascribed to their different protein purity .

The high level of lipids in Hemp 3 protein concentrate could have also played a role in the flowability and shear and tensile stresses of the melt inside the extruder, lowering the SME response during processing from 325 kJ/kg for EHemp5 to 285 kJ/kg for EHemp3. The content of phytic acid in dry-fractionated hemp  was found in the upper part of the typical high valuesreported for oilseeds, vertical grow which was in turn higher than the content typically found in cereals and legumes . For this reason, the content of phytic acid was also measured in HHMAs. The content of phytic acid naturally decreased in HMMA in proportions generally explained by the dilution effect of the protein concentrates with starch and water. Therefore, and as expected, extrusion did not reduce the content of phytic acid due to its known high thermal stability . Likewise, Pontoppidan, Pettersson, and Sandberg  already reported that the degradation of myo-inositol hexakisphosphate in feedstuffs during extrusion is too limited to have any nutritional effect on the availability of phosphorous and minerals. From the phytic acid perspective, if our developed HMMA prototypes were to be consumed as they come out from the extruder, that is, without further water removal  or water addition , a 100 g single portion  would contain a total of 0.6–0.7 g of phytic acid in EPea and EHemp5, and 1.8 g of phytic acid in EHemp3. Remarkably, the consumption of EPea and EHemp5 would not necessarily increase the daily intake of phytic acid in consumers following a plant-based diet, reported as >1000 mg . On the other hand, the consumption of EHemp3 could potentially result in a higher average daily dietary phytic acid intake in humans following a plant-based diet living in certain European countries, such as Sweden . It is noteworthy that the inhibition of the intestinal mineral absorption can be counteracted by many dietary compounds such as organic acids and complexing agent like ascorbic acid, competing with phytic acid for mineral binding. Thus, little evidence exists that in well-nourished population groups dietary phytate may seriously affect the status of iron, zinc, and calcium . On the other hand, phytate may lead to serious deficiencies with unbalanced nutrition or undernourishmentin developing countries. In this case, dry-fractionated protein concentrates from different botanical original than hemp, or wet-fractionated hemp samples, would be preferred. At any event, the consumption of dry-fractionated hemp HMMAs would result in average daily dietary phytic acid intakes within the range found for adults living in developing countries . Industrial hemp  is an annual, bushy, dioeciously or monoecious herbaceous plant which belongs to the family of Cannabaceae, genus Cannabis.

The industrial and medical importance of Cannabis sativa L. is reflected in the increasing market interest for consumables, fiber, medicine and miscellaneous products derived from raw or dried cannabis plant parts. The moisture removal of the harvested goods is one of the most important unit operation, in which the moisture is reduced to a certain balance level that the deterioration and microbial spoilage are minimized. In order for efficient, feasible and properly dimensioned convective drying systems to be deployed, accurate modeling of each raw material behavior during the drying process is required. Several mathematical thin-layer drying models are proposed in the literature for describing the drying kinetics in a range of agricultural products. More sophisticated approaches of drying scheme implementations arise in the scope of improving drying time, cost and energy, since the convective drying is an energy-intensive and slow process when low temperature levels are applied. Non-isothermal drying, implementing a variable mode of drying conditions by modifying as a function of time, one or more drying parameters is a technique followed by many researchers, also applied for herbaceous materials, as a nonstandard drying process aiming to reduce energy consumption, improve the product quality or reduce the required drying duration. In a study presented by Ozguven et al., peppermint was dried at two constant drying temperatures of 35 and 55 ◦C and two incremental temperature rises of 5 and 2.5 ◦C⋅h-1. Both non-stationary temperature profiles had a shorter drying duration a lower final moisture content compared with the lowest constant temperature level applied. A similar study was performed by Tarhan et al. forlemon balm .

Like tobacco smoke, marijuana smoke has been associated with numerous adverse pulmonary effects in humans including airway inflammation, chronic bronchitis, edema, mucus hypersecretion, and the impairment of large airway function and lung efficiency.Moreover, Aldington et al. showed that the impairment of large airway function and lung efficiency is 2.5–5 times greater in marijuana smokers than tobacco smokers.Like tobacco smoke, previous studies have also shown marijuana smoke to be genotoxic both in vitro and in vivo.In addition, it is suspected that marijuana smoke may be carcinogenic.Indeed, some agencies such as the California Environmental Protection Agency have placed marijuana smoke on their list of chemicals known to cause cancer.However, since there is a paucity of marijuana-only smoking populations to complete definitive studies, epidemiological studies conducted to date are limited in scope, and often confounded by concurrent tobacco smoking.Therefore, a clear and widely accepted empirical link between marijuana smoking and cancer does not exist. Information on the pharmacokinetics of marijuana smoke, and the mechanisms by which it may cause adverse effects, is also limited. Several mechanisms have been proposed including genotoxicity,alterations in endocrine function,alterations in cell signaling pathways,and immune suppression. However, many of these findings are based on the testing of individual cannabinoids  found in marijuana smoke, as opposed to the whole smoke or smoke condensate. Genome-wide expression profiling may provide information to permit a better understanding of the toxicological pathways perturbed by exposure to marijuana smoke. Currently, there are no published studies that have used a whole genome toxicogenomics approach to evaluate responses to marijuana smoke.

However, Sarafian et al. employed a targeted stress response gene expression array to evaluate the effects of 9-tetrahydrocannabinol,plant benches the main psychoactive component of marijuana, on human small airway epithelial cells.They observed significant changes in genes related to xenobiotic metabolism,DNA damage response,inflammation  and apoptosis.Microarray technology has been used more extensively to evaluate gene expression changes following exposure to tobacco smoke. For example, Sen et al. reviewed 28 studies examining transcriptional responses to complex mixtures including whole cigarette smoke and cigarette smoke condensate, and included in vivo and in vitro studies using human and rodent tissues.It was determined that the pathways most frequently affected by tobacco smoke were oxidative stress response, xenobiotic metabolism, inflammation/immune response, and matrix degradation. Other microarray studies have noted a DNA damage response leading to cell cycle arrest and apoptosis to be among the top pathways affected by tobacco smoke.The results of this study showed extensive overlap with the affected pathways highlighted in the review by Sen et al..Our study also showed that gene expression is remarkably similar across cigarette brands, and there is limited variation in the genotoxic potency of cigarette smoke condensates. In contrast to these findings, our earlier work revealed that tobacco and marijuana smoke condensates  differ substantially in terms of their genotoxicity.More specifically, MSC were observed to be significantly more cytotoxic and mutagenic than matched tobacco smoke condensates.In addition, TSC appeared to induce chromosomal damage  in a concentration-dependent manner, whereas matched marijuana condensates did not. The mechanisms underlying these differences in toxicity are unclear and warrant further investigation. As an extension of our previous work, the objective of the present study is to employ a toxicogenomics approach to compare and contrast the molecular pathways that are perturbed by MSC and TSC.

A murine pulmonary epithelial cell line was employed for in vitro exposures to both MSC and TSC. The results show that the pathways perturbed by MSC as compared to TSC are largely similar. However, subtle differences in gene expression provide insight into mechanisms underlying the observed differences in toxicities.Hierarchal clustering using all genes that were statistically significant  revealed that the controls and the marijuana high concentration  clustered independently from the rest of the samples. The remaining samples clustered first by concentration ,then by condensate type,with the last branching resulting from time.When cells exposed to TSC and MSC were analyzed separately, samples clustered first by concentration and then by time point, suggesting that concentration has the largest overall effect on gene expression. For MSC, the high concentration samples were on the first main branch, followed by control, low and medium concentrations. The results indicate that the expression profiles of the high concentration MSC exposed cells are quite distinct.For TSC, the controls branched separately from all the treatment groups.The top 10 genes with the largest overall fold changes are listed in Table 2. All of the top 10 genes were significantly up-regulated with the exception of low density lipoprotein receptor,which was down-regulated in MSC exposed cells. Of the top 10 changing genes, five genes  were common to both MSC and TSC. The GO terms  associated with these commongenes included multicellular organismal development, vasculogenesis, regulation of transcription, and regulation of inflammatory response. Ingenuity Pathway Analysis  was used to define the pathways that were significantly altered following exposure to MSC or TSC. Fig. 3 shows the overlap in all the significant pathways between the two condensate types. The top five most significantly altered pathways for cells treated with MSC or TSC are listed in Table 3. NRF2-Mediated Oxidative Stress Response was the most significant pathway for cells exposed to TSC at all concentrations and time points, with the exception of lowest concentration attime 6 + 4 h where LXR/RXR Activation  was the most significant.

For cells exposed to MSC, the most significantly altered pathways were Biosynthesis of Steroids, as well as NRF2-Mediated Oxidative Stress Response, Aminoacyl-tRNA Biosynthesis and HMGB1 Signaling.Some ofthe top five pathways were common to both the MSC and TSC including those related to oxidative stress and xenobiotic metabolism. However, inflammation pathways were more predominant for the MSC, whereas cell cycling and cancer signaling pathways were more predominant for the TSC. To further elucidate differences between the two smoke condensates, the genes that were uniquely expressed following TSC exposure or uniquely expressed following MSC exposure at the highest concentrations for the two separate time points were compared in IPA.The findings confirm the importance of inflammation and steroid biosynthesis pathways in MSC exposed cells and highlight the significance of apoptotic pathways  particularly at the 6 h time point. For cells exposed to TSC,Mphase cell cycle pathways  appear to be of particular importance. Gene Ontology in the Database for Visualization, Annotation and Integrated Discovery  was used to apply functionalannotation to all the significantly differentially expressed genes for each condensate. The full results are shown in Supplementary Tables 1 and 2. For cells exposed to MSC, significant perturbations were associated with steroid/cholesterol/lipid biosynthesis, NODlike receptor signaling,tRNA aminoacylation, transcription regulation, unfolded protein response and DNA binding. Like MSC, cells exposed to TSC had significant perturbations in transcription regulation, unfolded protein response and DNA binding. In addition, perturbations in cell cycle, p53 signaling, oxidative stress, andcancer signaling were alsonoted in TSC exposed cells. Fig. 5 shows the overlap of all the significantly affected ontologies between the two condensate types. Functional annotation clustering in DAVID was used to minimize redundancy in the GO terms. This analysis revealed 19 clusters with enrichment scores greater than 2 for MSC and 19 clusters for TSC.The top clusters for MSC relevant to toxicological processes include lipid/steroid biosynthesis,RNA processing,cellular response to unfolded protein,tRNA aminoacylation,and positive regulation of transcription.The top clusters for TSC relevant to toxicological processes include cellular response to unfolded protein,cell cycle,positive regulation of transcription,response to steroid hormone stimulus,and positive/negative regulation of apoptosis and cell death.To investigate early versus downstream effects, functional annotation was applied to significantly differentially expressed genes at the two separate time points. The results are shown in Supplementary Tables 5–8.

For cells exposed to MSC at the 6 h time point, the analyses revealed 79 significant  terms including those related to transcription activity, DNA binding, and steroid/cholesterol biosynthesis. Four KEGG pathways  and 1 Biocarta pathway  were also deemed significant at this time point. At the 6 + 4 h time point, 76 significant terms were identified. These terms included unfolded protein response, and tRNA aminoacylation, as well as steroid/cholesterol biosynthesis which was found at the 6 h time point. Three KEGG pathways were significant at this time point including Steroid Biosynthesis, Terpenoid Backbone Biosynthesis, and Aminoacyl-tRNA Biosynthesis. Analyses of cells exposed to TSC at the 6 hr time point revealed 67 significant terms including those associated with oxidative stress, cell death, protein unfolding, transcription regulation, DNA binding and cell cycle. In addition, 2 KEGG pathways were significant.At the 6 + 4 h time point, 32 GO terms were identified as significant with oxidative stress being the only relevant toxicological endpoint. In addition, only one KEGG pathway  was significant. Overall for MSC, the DAVID analyses confirmed many of the significant pathways identified by IPA including steroid biosynthesis, tRNA aminoacylation, inflammation and apoptosis. In addition, the analyses highlighted transcription regulation, DNA binding and unfolded protein response as also significant. For TSC, the DAVID analyses confirmed the significance of IPA pathways related to oxidative stress and cell cycle. As with the MSC, the DAVID analyses also further highlighted the importance of transcription regulation, DNA binding and unfolded protein response, as well as cell death. Transcription regulation and DNA binding were significant terms common to both MSC and TSC at the 6 h time point, whereas no common terms existed for the two condensates at the 6 + 4 h time point.In our previous genotoxicity study we showed that MSC and TSC were both cytotoxic and genotoxic.However, quantitatively, MSC was more cytotoxic and mutagenic than TSC, and TSC appeared to induce chromosomal damage in a concentration-dependent manner whereas MSC did not. Our earlier chemical analyses of MSC and TSC noted that aside from the nicotine in tobacco and the cannabinoids in marijuana, rolling bench the two smoke condensates contained mixtures of chemicals that were qualitatively similar though quantitatively different.The similarities in the chemical profiles and some of the toxicity findings suggested that the two smoke condensates might elicit somewhat comparable gene expression profiles. Hierarchal clustering of all the MSC and TSC exposed samples in the present study supported this notion  and samples clustered first by concentration as opposed to smoke type. In addition, analysis of the top ten greatest gene expression changes relative to control revealed that half of the genes were common to both marijuana and tobacco.

A number of previous studies have examined gene expression changes in pulmonary cells following exposure to tobacco smoke.Generally, these studies have shown that tobacco smoke stimulates xenobiotic metabolism, and that metabolized smoke constituents contribute to DNA damage. Following early insult, DNA damage leads to disruptions in the cell cycle such as arrest at the G2 checkpoint to allow time for response. Cellular response can include DNA repair, mutation induction through faulty repair or lack of repair, and programmed cell death of heavily damaged cells. Exposure to tobacco smoke can also trigger an inflammatory response and induce oxidative stress through increased levels of reactive oxygen species. Persistent induction of these processes following repeated exposure contributes to loss of normal growth control mechanisms, which is a key step in cancer development. Our study supports many of these findings, with exposure to TSC inducing the expression of genes involved in xenobiotic metabolism,oxidative stress,and DNA damage response as evidenced by changes in the expression of genes involved in cell cycle arrest, protein unfolding,transcription regulation, and inflammation.These same pathways were also significantly affected following MSC exposure, indicating that, as expected, MSC impacts many of the same molecular processes and functions as TSC. Although the effects of the condensates were largely similar, dose–response analysis indicates that the MSC is substantially more potent than TSC, with BMDs that in many instances are an order of magnitude lower than those for TSC. In addition, the results also highlighted some differences in steroid biosynthesis,apoptosis  and inflammation, which were more significantly affected following MSC exposure, and cell cycle,which was more affected following TSC exposure.IPA canonical pathways related to the metabolism of xenobiotics were significantly affected in both TSC and MSC exposed cells at both time points. These pathways included Xenobiotic Metabolism Signaling, Metabolism of Xenobiotics by CYP450, and AHR Signaling. For both TSC and MSC, the number of genes that were significantly affected increased with increasing concentration and the greatest number of genes changing occurred at the 6 + 4 h time point.

The results and conclusions from this study should be examined within the context of its limitations. First, the data-set examined in this analysis was derived from two larger parent projects,thus, certain variables of interest could not be manipulated or controlled to study more detailed MJ-related effects.In spite of these limitations, MJ users  were homogenous in their MJ use due to study inclusion criteria.In addition, we only had one memory measure common to examine across our combined sample. While the WMS-III story memory paradigm is a well-validated and researched instrument, it may not generalize to learning and memory processes in alternative nonverbal modalities. Further, using a memory measure with a somewhat higher executive loading such as an unstructured word list learning task may elucidate some of the differential effects of MJ versus nicotine on memory functioning. Lastly, the between-group differences observed in this study were characterized by small to-medium effect sizes and future research would be needed to replicate these findings in larger samples.Illicit marijuana use in the United States has been a longstanding public health concern for both adolescents and adults. As many as 44% of college-aged individuals endorse having used marijuana at some point in their life, and 21% of college-aged individuals report marijuana use in the past 30 days.Marijuana intoxication is associated with motor coordination deficits, euphoria, impaired temporal estimation, drying racks and a variety of other psychological phenomena.

Marijuana use has also been associated with more specific cognitive deficits, even after acute intoxication has subsided,and with the development of severe psychopathology.Furthermore, chronic marijuana use has been related to adverse physiological consequences in the cardiovascular and respiratory systems.Adolescence and young adulthood represent periods of the lifespan when increased risk-taking occurs, including the use of illicit substances, such as marijuana. The combination of an innate propensity for risk-taking  and use of a judgment-altering substance is a striking example of the immediate public health concern over marijuana use in young-adults. This concern is particularly pertinent in light of recent efforts in support of marijuana’s legalization in the United States. A challenge for the field is to identify which chemical systems and associated information processing networks are most affected by chronic marijuana use. The main psychoactive component of marijuana, Δ9 -tetrahydrocannabinol,acts as an agonist in central nervous system  cannabinoid  receptors and in other peripheral cell types, primarily immune cells. In the CNS, CB1 receptor density is high in the basal ganglia, particularly in the dorsal striatum.Cannabinoid receptor signaling acts on multiple neurotransmitters through a variety of biochemical cascades, including inhibition of voltage-dependent calcium channels  and by directly inhibiting vesicle release. Both excitatory and inhibitory neurotransmitters, including glutamate,γ-aminobutyric acid  and dopamine, are either directly or indirectly affected by CB1 receptor activation.For marijuana and other drugs of abuse and dependence, the dorsal striatum has been hypothesized to play a key role in the transition from intermittent drug use to compulsive habit-based drug-taking via mechanisms that underlie long-term synaptic plasticity.Exogenous activation of CB1 receptors, as occurs with marijuana intoxication, inhibits the release of glutamate as well as GABA in both the dorsal and ventral striatum.This inhibition facilitates the development of long-term depression  in the striatum, which is a critical component in the altered synaptic plasticity that accompanies drug addiction.Thus, the manner in which corticostriatal functional connectivity is altered in the context of marijuana use is of interest, as is metabolic activity within the chemical systems that contribute to those alterations.

Magnetic resonance spectroscopy is a widely used tool, allowing for in vivo characterizations of various brain metabolites. MRS data is acquired either from single voxel  or multiple voxels. The SVS method typically benefits from high spectral resolution and signal-to-noise ratio.MRSI has better spatial resolution compared to SVS, but typically has a much more limited spectral resolution.To the best of our knowledge, only four other studies utilizing some form of MRS to examine marijuana users have been published, and the methods of these studies are relatively heterogeneous.The existing studies are summarized in Table 1. Individuals ages 16-to-42 years were studied with either SVS or MRSI. In two of the studies, only males were examined.In most cases, marijuana use was reported at 20 or more days per month. Lower levels of Glu, N-acetylaspartate,and myo-inositol were observed in marijuana users compared to controls in regions known to be associated with substance use, including the basal ganglia,thalamus,cingulate cortex,dorsolateral prefrontal cortex,and the striatum as well as posterior cortical regions.The methods, ages of subjects, and extent of current marijuana use in the samples tested vary considerably across studies as summarized in Table 1. As disruptions in glutamate activity have been implicated in the development of addiction,we hypothesized disruptions in glutamate concentrations in marijuana users compared to controls. Several lines of evidence suggest inhibition of glutamate excitotoxicity by marijuana.In addition, based on the MRS literature described above related to the basal ganglia of adult marijuana users and literature describing the inhibitory effects of CB1 receptors on glutamate release, we specifically hypothesized that young-adult MJU subjects would show lower levels of Glu + glutamine in the basal ganglia compared to their non-using counterparts. We did not have a specific hypothesis regarding concentrations of other metabolites given that other researchers have not concentrated their assessments on the striatum. However, the limited available literature suggested the possibility of altered mIns as well as NAA levels in users versus controls.Twenty-seven marijuana users  were recruited into the study through local advertisements on the University of Minnesota-Twin Cities campus. Marijuana users’ ages ranged from 18-to-21 years, with a mean and standard deviation of 19.5 ± 0.6 years.Exclusion criteria are described below.

Twenty-six healthy young adult non-users,who were participants in a large, longitudinal study of normal brain development, served as a control sample. Control participants’ ages ranged from 13-to-24 years, with a mean and standard deviation of 19.3 ± 3.1 years. The recruitment strategy for the control sample has been described elsewhere.Briefly, participants younger than 18 years of age were recruited through a database of research volunteers throughout the Metro community, through post-cards mailed to University of Minnesota civil service employees, and through local advertisements. Participants over the age of 18 years were recruited using on-campus advertisements. During the controls’ third longitudinal follow-up visit, MRS was added to the protocol as time allowed. Thus, the control sample described in this study has a broader age range than the MJU sample, a feature that was considered in the statistical approach described below. A description of the study was initially given to both the MJU and control participants over the phone. Interested participants were then invited to complete a brief phone screening to ascertain study eligibility. Exclusion criteria included major physical, neurological or psychiatric illness, substance use disorders,head injuries resulting in loss of consciousness >20 min, mental retardation, learning disabilities, current use of psychoactive medications, non-native English speaking, vision or hearing that was not normal or corrected to normal, complications at birth, current pregnancy, and MRI contraindications.Inclusion criteria for MJU participants included current use of marijuana at least five times per week for at least one year, and an age of onset of use prior to the age of 17 years. Marijuana users were also excluded if they were daily cigarette smokers, or if their alcohol use exceeded four drinks for females and five drinks for males on more than two occasions per week. Marijuana users were asked to refrain from drug use for at least 12 h prior to their visit  to avoid acute intoxication during study procedures. Participants provided written informed consent  and all study procedures were approved by the University of Minnesota’s Institutional Review Board.After the phone interview, eligible participants were invited to the University of Minnesota’s Center for Neurobehavioral Development for an in-person screening session to further ascertain eligibility and to verify information given over the phone. The Kiddie Schedule for Affective Disorders and Schizophrenia, Present and Lifetime version  was used to assess for current or past Diagnostic and Statistical Manual, Fourth Edition  axis I disorders, including childhood disorders given the relative youth of the sample.

The presence or absence of DSM-IV disorders was confirmed by case consensus meetings with staff members including a license-eligible clinical psychologist. In addition, a two-subtest  version of the Wechsler Abbreviated Scale of Intelligence was administered to yield estimated full scale IQ.Participants who met all inclusion criteria after the in-person interview were invited back for a comprehensive neuropsychological testing battery and an MRI scan. This report focuses on spectroscopy findings.In addition to the K-SADS-PL, the Personal Experience Inventory   was used to further assess alcohol and marijuana use in both the MJU group and in the healthy controls. Briefly, the PEI consists of two main sections, one focused on patterns and severity of substance use, and the other focused on psychosocial consequences of use. In most cases, participants endorse items from the inventory using a four-point Likert response format.Different versions of the PEI have been developed for adolescents versus adults. Participants younger than 18 years of age received the adolescent version and participants older than 18 years of age received the adult version; both versions were computer administered. All MJU participants received the adult version. Scoring was implemented to create comparable metrics across the two versions. Finally, an in-house questionnaire based on guidelines provided by the National Institute on Alcohol Abuse and Alcoholism was implemented to assess detailed daily, weekly, yearly and lifetime use patterns of alcohol and marijuana in the sample, considering frequency and amount of use.This study examined a cohort of college-aged heavy cannabis drying users and a control group of non-using young-adults. Using MR-spectroscopy, it was shown that females, but not males, who used marijuana heavily starting in mid-adolescence and persisting for several years have lower levels of glutamate and glutamine  in the dorsal striatum when compared to controls, even after accounting for age and alcohol use. Similarly, female but not male users differ from controls in their estimated concentrations of myo-inositol, demonstrating higher levels than controls. These patterns are interpreted as pathological in the female users given that male users had comparable levels to controls of both sexes. Female users did not differ from male users in their overall rates of self-reported marijuana use, in their concomitant level of alcohol use,in their numbers of symptoms of marijuana dependence, or presence of other conditions that might impact brain metabolism.These findings have broad parallels in the extant literature, both in relation to the overall patterns observed but also in relation to sex differences.

Decreased glutamate/glutamine concentrations have been reported in two other MRS studies of marijuana users, one that focused on the basal ganglia  and one that targeted the anterior cingulate cortex.First, in an older cohort of marijuana users than is described in the current study, Chang et al.  reported lower glutamate levels in the basal ganglia, suggesting that heavy marijuana use during young adulthood as well as later in life is associated with disruptions in glutamate signaling as has been shown for other drugs of abuse.Recently, Prescot et al.  reported lower glutamate concentrations in the anterior cingulate cortex, which was nonetheless strongest when females were eliminated from the analysis. Interpretation of the current findings is complicated by poor resolution of the glutamate versus glutamine signal. Glutamate is present in all cell types with the largest pools evident in glutamatergic neurons; smaller pools are evident in GABA-ergic neurons and astroglia. Upon release, astroglia convert glutamate to glutamine, which in turn is transferred back to the neuron for conversion once again to glutamate.Glutamine is primarily located in astroglia. Thus, low glutamate levels would be difficult to ascribe to a particular neuronal process. In contrast, if glutamine levels are low, then glial dysfunction may be present, a finding that would be consistent with white matter aberrations in marijuana users.Others have not reported specific metabolic disruptions in female marijuana users; indeed, within young samples, marijuana is more commonly used in males.Although it has been recognized that females are at an increased risk for some behavioral consequences of drug use such as sexual risk-taking  and an increased risk of depression and anxiety following a pattern of daily marijuana use,there are relatively few human studies of brain-based sex differences associated with marijuana. Women have shown slightly more severe neurocogntive deficits related to marijuana use compared to men.

A major strength of this study was its large international multicentre prospective cohort with excellent follow-up and complete data available for this analysis. Women were recruited from a clearly defined population of nulliparous women, with meticulous data monitoring protocols to reduce data entry or transcription errors and ensure the quality of data. While there are other studies that have examined the effect of marijuana use on adverse pregnancy outcomes, interaction tests were not performed. Hence, with complete quality data available from this study, interactions between marijuana use and cigarette smoking status may be examined while also adjusting for potential confounders. It needs to be noted that the number of SPTB cases amongst women who reported marijuana use at 20 weeks’ gestation is small  even in this large cohort. The use of self-reported marijuana use and cigarette smoking status may be a potential limitation, as it may be subject to participant recall bias. Furthermore, this study was undertaken in a nulliparous cohort so it may be the case that our findings apply only to nulliparous women. Although medication for maternal asthma, thyroid disease, and PCOS were recorded, we found no evidence of association with pregnancy outcomes analysed in this study, therefore these were not included in the analysis. Further research is required to confirm these findings, and future studies should include appropriate corrections for the various important confounders .Tobacco smoke can cause numerous health related issues. While cigarette smoking is associated with the development of certain respiratory diseases, the causal link between the onset of asthma and smoking has not been established. To date, studies that examined the association between cigarette smoking and incident asthma have shown mixed results.

Previous work on the topic has reported an increased risk for adults and adolescents but others reported no statistically significant associations. Although what causes the onset of asthma is still relatively unknown,grow cannabis in containers experts in the field have reported that cigarette smoking or exposure to second hand smoke can certainly trigger asthma symptoms and severity. Overall cigarette smoking or second hand smoke can relate to many long term respiratory health issues, but it can also influence more immediate issues for people with asthma including increased coughing and airway inflammation. For adults in California, cigarette smoking was associated with asthma severity, worse asthma-specific quality of life and greater hospitalization for asthma. Furthermore, active cigarette smoking for people with asthma can lead to accelerated loss of lung function and a decreased response to corticosteroids over time. In the past, studies on smoking behaviour in adolescents was focused on cigarette use; however, more recently other types of smoking such as water pipes, marijuana or now electronic cigarettes  have emerged as a concern. water pipes  have become more popular in North America in recent years due to the belief that it is a safer alternative to cigarettes. This is a common misconception in young adults, as a water pipes smoking session can contain over 100 times the amount of smoke in comparison to a single cigarette. In Ontario, the rate of trying water pipes in adolescents has more than doubled from 6% in 2006 to 14% in 2013. Water pipe smoking is linked to several adverse health outcomes such as cancer, cardiovascular disease and decreased lung function. While the causal effect of water pipe smoke and asthma has not been demonstrated, exposure to tobacco smoke was shown to exacerbate asthma symptoms. Since water pipes produce tobacco smoke, it can be assumed that it will be harmful especially for those with asthma. The relationship between marijuana smoking and asthma is somewhat complex. Marijuana has been used as a forbidden medicine to treat asthma symptoms for years as it may have bronchodilator properties,while long term marijuana smoking has also been associated with increased respiratory symptoms.Overall, the relationship between marijuana and lung health is somewhat mixed and the connection may not be the same as tobacco smoke. Previous research has suggested that adolescents with asthma smoked significantly more marijuana than those without asthma.

However, the number of adolescents  who smoked marijuana in Canada has decreased from 32.7% in 2008 to 24.4% in 2013. Electronic cigarettes are battery powered devices that vaporise nicotine and/or other flavouring mixes, but do not burn tobacco. These products have become popular in recent years and they are perceived as a safer alternative to tobacco cigarettes. While preliminary studies suggest that they may be less harmful than cigarettes, the long term health effects and how e-cigarettes relate to asthma symptoms or severity are unknown. The Canadian Tobacco, Alcohol and Drug Survey reported that as many as one in five  adolescents aged 15e19 tried e-cigarettes, however, the absolute trend of usage is still unknown as these products are relatively new. The purpose of this paper is to examine whether adolescents with asthma smoke cigarettes, water pipes, marijuana or e-cigarettes more or less than those without asthma. This study adds to the current literature by examining all smoking habits for youth with asthma, rather than focusing just on cigarettes.The 2013 Ontario Student Drug Use and Health Survey  is a population based survey conducted every two years and completed by grade 7e12 students at publically funded schools in Ontario, Canada. Ontario is the largest province in Canada with a population of over 13 million residents. Ontario includes major urban centres such as Toronto and Ottawa, several smaller cities and an abundance of rural lands. The OSDUHS is designed to collect information about drug use and other health related behaviours among students in Ontario. All parents and students gave consent prior to participation. To examine the association between smoking and asthma, we limit our study sample to high school students  in 109 schools. These schools were selected with probability proportional to size, to obtain a representative sample within the province. The survey included questions that captured information on self-reported doctor diagnosed asthma and data on tobacco, alcohol and drug use. The survey used a random split-ballot design where some of the questions change on each of the surveys. The sample is randomly divided into 2 groups to maximize questions included and minimize burden on students, but it reduces the sample size for some questions. In the OSDUHS, approximately half of the full sample answered questions pertaining to asthma and all types of smoking reducing the sub-sample to 2,840. Data are representative of students in Grades 9 to 12 attending publicly funded schools in Ontario.

Ages for respondents range from 12 to 19 years of age.In Ontario, the majority of children  attended publically funded schools, 5% attended private schools, and another 3% were either home schooled, institutionalized for correctional or health reasons, schooled on a First Nation reserve,military base or lived in remote northern region. This study was approved by the research ethics board at the Research Institute of The Hospital for Sick Children.The primary outcome variables in this study are smoking status with regard to cigarettes, water pipes, marijuana and e-cigarettes. Self-reported frequency and intensity of cigarette, water pipe, marijuana and e-cigarette smoking in the last 12 months and lifetime use were measured in the survey. Cigarette non-smokers were classified as those who never smoked a cigarette or smoked less than  one cigarette in the last 12 months, while cigarette smokers were those who smoked more than one cigarette in the past 12 months. Similarly, smoking status for water pipe was also classified as a binary outcome variable. Respondents were asked how often they smoked a water pipe  in the last 12 months. Those who smoked a few puffs, never smoked, haven’t smoked in the past 12 months or didn’t even know what it was were considered non-water pipe smokers. Those who smoked one or more times were defined as smokers. Marijuana smoking is also defined in a similar manner. Students were asked how often they smoked cannabis  in the past 12 months. If they smoked 1 or more times in the past year they were classified as a marijuana smoker. Respondents who have never or not smoked in the last 12 months were considered to be non-marijuana smokers. Finally, respondents were classified as e-cigarette smokers if they smoked an e-cigarette with or without nicotine in it, pot for cannabis while those who have never smoked or never heard of e-cigarettes were considered non-smokers.The primary risk factor of interest is the presence of asthma which is captured by the response to the question “has a doctor or nurse ever told you that you have asthma”. Other potential confounding variables include: grade,sex and socioeconomic status.SES was measured by a 10-point social ladder. Students were asked to imagine that the ladder represents how Canadian society is set up, where the people at the top of the ladder are the “best off”, meaning they have the best jobs, make the most money and have the highest education. Those at the bottom of the ladder are the “worst off”, with no job, or a job no one wants, little education and the least money. Respondents reported what best represents their family on a 10-point scale, which was further grouped into three levels  based on the interquartile ranges.

While cigarette smoking may aggravate symptoms and severity for adolescents with asthma, some work on the topic suggests that the prevalence of cigarette,water pipe and marijuana smoking was actually higher in adolescents with asthma than those without. These studies, however, are not conclusive as at least one reported that adolescents with asthma were less likely to smoke cigarettes. It is reasonable to suppose that adolescents with asthma will not smoke as it will aggravate their asthma severity and symptoms,but this unfortunately may not be the case. Our study showed that students in grades 9e12 with asthma in Ontario, had a higher odds of smoking e-cigarettes or any substance than their peers who do not have asthma. The odds of smoking ecigarettes for adolescents with asthma, was nearly twice as high as those without asthma after adjusting for age, sex and SES. Given the cross-sectional design of the survey, we cannot infer the causal relationship between smoking and asthma. Previous studies suggest that smoking for adolescents with asthma may relate to the desire to obtain social status among one’s peers, and not wanting asthma to interfere with their social status. Of all demographic characteristics studied, student’s grade was most significantly associated with smoking cigarettes, water pipes and marijuana. A longitudinal study in the United States found that rates of cigarette smoking increased from 1.8% at the age of 9 to 22.5% by age 16. Findings suggest that rates for smoking cigarettes and water pipes among grade 9 students were relatively low,but doubled in grade 10, tripled by grade 11 and quadrupled by grade 12.Cigarette and water pipe smoking became more popular in grade 10 and the trend continued as they aged. E-cigarette smoking on the other hand only marginally increased from grade 9 to 12.For adolescents with asthma, rates of e-cigarette smoking were similar to that of the entire sample, ranging from about 10% in grade 9 to 16.7% in grade 12. Our study also showed that cigarette, marijuana and any smoking rates were inversely related to SES, where lower SES was associated with higher odds of smoking. Our finding is consistent with the literature that suggests an inverse relationship between individual SES or parental education and cigarette smoking in adolescents. It has been suggested that lower SES households may have a poorer attitude towards health, fewer opportunities or more stressful situations which make them more likely to smoke.This study had many strengths which relate to the size and generalizability of the survey sample and the fact that it examined how all types of smoking related to asthma prevalence. That being said, there are also some limitations. The primary purpose of this survey is to examine health risk behaviours of adolescents in Ontario and not asthma. As such, the number of respondents with asthma was low and this may have contributed to some of the insignificant findings.

Despite the high co-morbidity between marijuana  and nicotine  use, only few studies have directly addressed the mechanisms that lead to their concurrent use. This includes route of administration,cross drug adaptation, response to treatments, environmental effects and genetic factors.Others have also alluded to the “gateway drug” hypothesis whereby the use of one drug may potentiate the effects of the other. For example, in a longitudinal study in 14–15 year olds, marijuana use increased the likelihood of initiating nicotine use up to 8 times and developing nicotine dependence up to 3 times suggesting marijuana’s role as a gateway drug.This was further supported by findings showing that women who used marijuana were at 4.4 odds of later developing nicotine use and dependence.The same group also reported in 43,093 adults that nicotine smoking increased the risk for marijuana use and dependence up to 3 times.This latter finding suggests a bi-directional potentiating effect and indicates that more complex factors may drive combined use. Although the animal literature has characterized the neural mechanisms that may underlie these potentiating effects, it is also possible that personality factors contribute to this phenomenon. Combined marijuana and nicotine use has been associated with differential effects on clinical diagnoses, cognitive and psychosocial problems, and outcomes.For example, Bonn-Miller and colleagues examined associations between negative emotions  that discriminate marijuana-only users from co-morbid marijuana and nicotine users.They found that, in general, nicotine-only using individuals had significantly greater negative emotionality than marijuana users, co-morbid marijuana and nicotine users, and non-using controls. Earlier work by Degenhardt showed that while nicotine and marijuana use were both individually associated with increased rates of negative emotion, this relationship appeared to be driven by neuroticism in marijuana users.

Taken together, these studies argue for different patterns of co-morbidity in nicotine and cannabis grow equipment using populations. To date, however, distinctions in trait markers, such as personality factors, have not yet been addressed in this ubiquitous group of co-morbid users. These differences suggest the need for fine-tuning the ability to discriminate risk-profiles between these groups as they also relate to clinical treatment outcomes. Factors that contribute to risk profiles include personality traits that have been examined as putative markers for treatment outcomes. For example, in a prospective four-year study in 112 adults with chronic alcoholism, Krampe et al.  determined that the presence of any personality disorder was associated with a decrease in four-year abstinence probability. Similarly, using the NEO Personality Inventory-Revised  Betkowska-Korpala  found that following treatment, abstinent patients have higher levels of agreeableness and conscientiousness than patients who relapsed within a year following the therapy. This suggests that personality profiles have high predictive values for SUD outcomes and should be considered during treatment programs. However, to date, only few studies have examined personality factors that distinguish marijuana from nicotine users and even fewer differentiate isolated use from combined use. In terms of isolated use, high openness but lower agreeableness and conscientiousness in marijuana users relative to non-users has been noted,suggesting that marijuana users differ from non-users on dimensions of normal personality traits as measured by the Big Five model of personality. Conversely, greater extraversion is widely reported in nicotine-only users,as well as high neuroticism  and impulsivity.Studies that have performed direct contrasts between isolated marijuana and nicotine users have also shown differences between the two groups. For example, using the wide spectrum Five-Factor Model of personality, Terracciano et al.  showed that nicotine users had lower conscientiousness and higher neuroticism whereas marijuana users had high openness, average neuroticism, and low agreeableness and conscientiousness. However, these studies did not examine personality factors in co-morbid nicotine and marijuana users.

These traits together suggest that co-morbid users would have a personality profile endorsing high openness and neuroticism, but comparatively less of these traits than isolated users. Personality factors are markers that can be used as endophenotypes for substance use disorders  particularly because brain circuits involved in personality traits are also implicated in SUD.For example, emergent literature has classified the Big Five personality model via machine learning techniques from resting state fMRI data.These studies indicate that neuroticism negatively correlated with activity in the middle frontal gyrus and precuneus; extraversion correlated positively with regional activity in the striatum, precuneus, and superior frontal gyrus; openness correlated positively with activity in the thalamus and amygdala, and negatively with the superior frontal gyrus; conscientiousness correlated positively with regional activity of the middle frontal gyrus and correlated negatively with the cerebellum.While these findings have not been consistent across studies, they suggest underlying neurobiological mechanisms/pathways that confer personality factors particularly in similar neural substrates implicated in SUD. Altogether, better understanding of the links between personality and SUD can provide understanding of the brain circuits implicated in SUD that could improve prevention and intervention. Given the paucity in the literature on personality factors that discriminate co-morbid from isolated marijuana and nicotine use, this study examined differential NEO personality profiles in marijuana only, nicotine only, co-morbid marijuana and nicotine use and non-using controls. Because the existing literature has shown that marijuana users and nicotine users differ on openness and neuroticism, we predict that comorbid users would have a personality profile high on these two personality traits, but intermediate to that of the isolated users.Participants were recruited from the general community through flyers and newspaper advertisements to participate in a study to determine behavioral and neural associations of substances at the Mind Research Network in Albuquerque, New Mexico. All participants were between the ages of 1855, without current Axis I disorders, not currently taking any psychotropic medications, and, have no history of brain injury. Because these data were collected as part of a larger fMRI study, participants were further required to be free of MRI contraindications  and be right-handed.

Of the 224 individuals who met study criteria, 80 participants were excluded for having a lifetime substance use disorder other than marijuana and nicotine. Two participants were also excluded due to missing data. Thus, analyses for this study were conducted on a sample size of 142.We then categorized the participants into four groups based on their primary and regularly-used substance: marijuana-only,nicotine-only,co-morbid marijuana and nicotine  and non-using control  groups. For the marijuana only group, regular marijuana use was defined as at least four times a week for the previous six months.For the nicotine-only group, regular nicotine use was defined as smoking at least ten cigarettes per day.The combined marijuana and nicotine group consisted of those who use both marijuana and nicotine regularly, as defined by 60 days out of the past 90 of concurrent use. The non-using control group consisted of participants that were neither regular users of marijuana or nicotine. Table 1 summarizes the substance use characteristics for all of the groups.Because we were interested in patterns of personality traits  that distinguish co-morbid users of both marijuana and nicotine from the marijuana-only or nicotine-only users, we first used a factor analysis with VARIMAX orthogonal rotation method to identify unique relationships  between each NEO personality dimension variable and unobserved latent factors. This method allowed us to combine these five factors into linear models that we could then test in linear regression given our sample size. The logistic regression model was used to estimate how much the two significant personality factors derived from factor analysis discriminate marijuana-only, nicotine-only, co-morbid marijuana and nicotine users, and, controls controlling for covariates of sex, age, race, and education. Odds ratios  and 95% confidence interval  estimates were presented as results. Further, in order to test accuracy in personality factors’ discriminability of groups who use marijuana only from nicotine only and neither marijuana nor nicotine use, 70% of area under the Receiver Operating Characteristic  curves was set as a minimum value for an accuracy of classification.In addition to personality factor patterns as predictors, we also examined the group variance in each NEO personality dimension using Analysis of Variance.ANOVA was run for all five dimensions separately controlling for covariates of sex, race, age, and education. Post-hoc pairwise comparisons between two diagnosis groups were conducted if an overall group effect was statistically significant  and Tukey-Kramer adjusted p values were then reported.

SAS 9.4 version  was used for all statistical analyses and p value less than 0.05 was set as a statistical significance level.A factor analysis was conducted to identify personality profiles that discriminated the groups. The factor analysis identified two personality factors 1 and 2, which were linear associations of all five of neuroticism, extraversion, openness, agreeableness, and conscientiousness NEO Personality Inventory dimension t scores. Each factor-loading pattern is described in Table 3. Two dimensions, neuroticism  and conscientiousness,near equally loaded high to factor 1, while the rest of dimensions, extraversion loaded the highest,followed by openness  and agreeableness,loaded high to factor 2. 3.3. Paired comparisons and logistic regression To investigate the discriminatory effectiveness of personality factors of marijuana use among four groups,we used three paired comparisons: marijuana-only vs. all other groups, marijuana-only vs. nicotine-only, and marijuana only vs. controls.A logistic regression model consisted of two personality factors and covariates of sex, race, age, and education. Logistic regression results showed that as personality factor 2 score increased by 1, the odds of using marijuana increased by 180% compared to non-marijuana using groups, respectively. However, personality factor 1 did not significantly discriminate marijuana group from the other groups.Regarding demographic variables, these comparisons also demonstrated that older participants were less likely to use marijuana, and that females had significantly lower odds than males of using marijuana only compared to neither marijuana nor nicotine use. Additionally, as years of education increased by 1 year, the odds of marijuana use decreased by 74%. The study model was able to discriminate marijuana users from the rest with 83% accuracy, while each personality factor alone discriminated marijuana users from the rest of the sample with less than 60% accuracy.When comparing marijuana-only and nicotine-only groups, neither factor 1 nor factor 2 alone discriminated marijuana-only users from nicotine-only users with greater than 70% accuracy. However, a model with both personality factors and demographic covariates discriminated marijuana only use from nicotine users with 80% accuracy.When comparing the marijuana-only group with the control group, neither factor 1 nor factor 2 alone discriminated marijuana only users from the control group, while a model with both personality factors and demographic covariates discriminated marijuana only use from the control group with 85% accuracy.While no significant overall group effect was found in any of Together, these observations indicate clear personality differences between individuals who use marijuana, nicotine, or both,mobile grow system and implicate differences in treatment between these populations.The aim of this study was to determine personality profiles that distinguish marijuana users, nicotine users, and, co-morbid marijuana-nicotine users. Factor analysis showed that a model with both personality and demographic factors discriminated marijuana users from non-users better than personality factors alone. Logistic regression found strong effects of age, sex and years of education in discriminating marijuana users from non-users whereby the odds of using marijuana increased by being male, younger and less educated.

A model with both personality and demographic factors also discriminated marijuana users from nicotine users with high predictability. ANOVA results showed that the openness dimension discriminated the marijuana users from all other groups and the marijuana-nicotine group from the nicotine users. These findings suggest that the discriminability of the co-morbid group from the nicotine-only and non-using group is primarily due to the contributions of marijuana use. The larger contribution of marijuana in concomitant users in terms of risk is in line with studies that found that the association between comorbid use and negative emotion is largely driven by marijuana users.Our findings are concordant with the literature that showed openness discriminates marijuana users from other groups.Openness identifies the seeking of experiences for their own sake.Relative to marijuana, nicotine use does not have the burden of legal consequences and therefore may not require the same degree of openness as marijuana use. Our findings are also concordant with those suggesting that agreeableness and conscientiousness are lower in drug users.Our findings further add to this literature by showing that agreeableness and conscientiousness in marijuana users are intermediate to that of non-using controls and nicotine users.Interestingly, studies have also reported that extraversion is traditionally lower in drug users compared to non-drug users suggesting that extraversion may confer resilience to the development of addiction disorders in general.