A log-rank test was used to determine the significance of difference between two survival curves. All analyses were conducted using JMP staThistical softwar.Survivorship of adults reared from wild-caught larvae and pupae was examined in three different environments: indoor, plantation, and forest . Female mosquitoes placed indoors survived significantly longer than those in banana plantation and forest for both An. minimus and An. sinensis . The mean survival duration of female An. minimus mosquitoes were 21.6, 18.8 and 14.8 days in indoor, banana plantation and forest, respectively . A similar result was found in female An. sinensis mosquitoes in different land use and land cover settings. Male mosquitoes lived for a significantly shorter period of time than females for both An. minimus and An. sinensis, but the pattern of survivorship in indoor, banana plantation, and forest environment was the same as the females . The daily survival rate ranged from 0.88 to 0.91 for females and 0.84 to 0.89 for males .The present study identified a significant effect of land use and land cover on vector survivorship. Mosquitoes placed under indoor environment exhibited significantly higher survivorship and longevity than banana plantation and forested environment. When mosquitoes were placed indoors in two sites differing in elevation, cannabis grow setup mosquitoes exhibited higher survivorship in sites with lower elevation. The effects of land use and land cover on mosquito survivorship likely resulted from differing microclimatic conditions among the habitats where adult mosquitoes were placed.
Significantly higher mosquito survivorship was found in an indoor environment where mean daily temperature was 2°C higher than in the forested environment. This result on the impact of land use and land cover on mosquito survivorship was consistent with other studies on An. arabiensis and An. gambiae in African highlands , and An. darlingi in the Peruvian Amazon. The findings from this study have important implications for understanding malaria transmission and vector control in changing ecosystem. The developing world has been experiencing rapid land use and land cover changes. Deforestation is a major component of land use and land cover changes. Increased survivorship of adult mosquitoes in the indoor environment indeforested areas, as demonstrated in the present study, suggests that Indoor Residual Spraying and Insecticide-Treated Nets should be used for vector control to prevent indoor malaria transmission. In addition, deforestation could alter the microclimatic conditions of aquatic habitats and subsequently enhanced survival and development of larval mosquitoes as demonstrated in An. gambiae and An. arabiensis in Africa. Because vector survivorship and vector density are important components of vectorial capacity, deforested agricultural areas could exhibit dramatically higher vectorial capacity than forested areas. Therefore, deforested agricultural area can increase the risk of malaria transmission. There are several limitations in our study. First, although it is a conventional method, microcosm rearing of mosquitoes in cages for determination of vector survivorship was in a confined condition. In field conditions, mosquitoes could hide and rest in moisture and dry habitats with microclimate conditions that are different from our cage condition.
Because it is not feasible to track the mosquitoes under field conditions, determination of vector survivorship under field conditions has been indirect based on biomarkers such as ovarian structural evaluation, fluorescent pigment pteridine concentration, cuticular hydrocarbon, and gene expression. These methods have significant limitation in estimation reliability such as the age of mosquitoes beyond certain period cannot be identified, and sensitive to blood feeding and other physiological changes. Our microcosm rearing of mosquitoes is the most direct measurement of mosquito survivorship. Second, we fed mouse blood and sucrose sugar in our experiments. The food source to adult mosquitoes may affect survivorship as An. minimus prefers biting human. Because all mosquitoes were reared under the same food condition, the results on the impact of land use and land cover should be valid. It is important to assess the impact of land use and land cover on vector-borne disease transmission when an economic development plan that significantly alters land use and land cover is being formulated. This study suggested that deforestation is the worst scenario, re-cultivation with banana plantation or other economically valuable trees such as rubber trees could boost incomes and reduce malaria transmission risk at the same time. Therefore, government policy should encourage local farmers to re-cultivate on deforested land. The estimated daily survival rate for An. sinensis and An. minimus under different land use and land covers provides a valuable parameter in modeling vector population dynamics and malaria transmission risk.When California voters approved Proposition 64 in 2016, legalizing recreational cannabis for adults, they fundamentally altered the state’s cannabis landscape. They also, albeit unintentionally, furnished UC researchers with intriguing new avenues of potential inquiry — many of which are blocked by federal law and pursuant UC policy. For example, researchers interested in the cannabis-derived sprays and beverages readily available at California’s retail cannabis establishments cannot obtain those products for research purposes by any permissible means. Licensed cannabis businesses dot the state today, but cannabis research still operates within the same strict constraints that have hindered it since legalization was a futile sentiment on a bumper sticker. Because state law is subordinate to federal law, Proposition 64 is subordinate to the 1970 Controlled Substances Act. Associated with that act is a “scheduling” apparatus, overseen by the Drug Enforcement Administration , that identifies cannabis as ripe for abuse and devoid of medical merit. Thus, along with heroin and other Schedule I substances, the psychoactive variety of cannabis cannot under federal law be cultivated, processed, sold, consumed — or, for the most part, researched.
The University of California, as a law-abiding institution, complies with the Controlled Substances Act and its nearly total cannabis prohibition. As an institution that receives federal funding, UC complies with the Drug-Free Workplace Act and the Safe and DrugFree Schools and Communities Act — which require universities, if they wish to receive federal funding, to implement policies prohibiting on-campus activities such as possession or use of controlled substances. UC personnel, including staff, faculty and UC Cooperative Extension specialists and advisors, are therefore prohibited, in their professional capacities, from direct contact with the cannabis plant or its extracts, and also from certain types of indirect contact. They cannot, for example, visit cannabis cultivation sites or advise cannabis growers on topics such as yield increases. Researchers can’t even use cannabis or cannabis-derived products in medical studies — unless they fulfill a rather daunting set of federal requirements. Those requirements for medical studies include obtaining a Schedule I license from the DEA; submitting research protocols for Food and Drug Administration approval; submitting to the FDA an investigational new drug application ; and, as a non-federal matter, gaining the approval of a state entity, the Research Advisory Panel of California . If all goes well, researchers can then obtain cannabis or cannabis-derived substances from a DEA-licensed cultivator, a DEA registered bulk manufacturer or, with a DEA import license, a foreign exporter. The only DEA-licensed cannabis cultivator is the University of Mississippi, which grows the plant under a contract funded by the National Institute on Drug Abuse . Bulk manufacturers of cannabis products such as tetrahydrocannabinol — the psychoactive component in cannabis — include, for example, vertical grow system the Massachusetts based life science company MilliporeSigma . Providers of imported cannabis products — such as Tilray, a Canadian firm — must be based in jurisdictions where such products are legal. No matter which path researchers choose, the process isn’t fast or easy. “You need a patient, dedicated team willing to jump through extra hoops at the institutional, state and federal levels,” says Jeffrey Chen, Executive Director of UCLA’s Cannabis Research Initiative. Even so, Chen reports, federal restrictions on types and sources of cannabis products can prevent researchers from conducting cannabis studies at all. And again, only medical researchers are eligible to obtain cannabis for research. Those who wish to perform agronomic studies, for example, are simply out of luck. For all that, opportunities to research cannabis are not scarce around the UC system. Observational studies of cannabis users are permissible, though the cannabis in question cannot be provided by the university and must be consumed off campus. Researchers interested in the legal or economic dimensions of cannabis, or in cannabis policy, will discover few obstacles in the Controlled Substances Act. Several UC researchers are vigorously investigating the environmental consequences of cannabis cultivation — and in fact Proposition 64 has effectively expanded the scope for such research. According to Ted Grantham, a UCCE specialist at UC Berkeley and co-director of the UCB Cannabis Research Center, researchers can now interact with cannabis growers — to learn, for example, about their cultivation practices — in a way that grower reluctance previously precluded. Today, Grantham reports, “a subset of growers is very interested in day lighting the cannabis industry to establish its legitimacy as an agricultural crop rather than an illicit substance.” In years to come, UC investigators will likely perform extensive research on industrial hemp.
This form of cannabis, which contains extremely small amounts of THC, is useless for producing a “high” — but very useful for making fabrics, insulation, paper and more. Until recently, however, federal law did not distinguish between low-THC hemp and high-THC cannabis — nor between THC and cannabidiol , a nonpsychoactive cannabis compound purported to relieve medical conditions ranging from arthriThis to anxiety. The legal landscape for hemp and CBD began to change on the federal level in 2014, when that year’s Farm Bill allowed universities to cultivate industrial hemp for research purposes . In June of last year, the FDA approved a CBD-based medicine for treatment of epilepsy-related seizures. With last December’s passage of the 2018 Farm Bill, industrial hemp became a legal crop — pending establishment of a regulatory framework to govern it. Hemp-derived CBD now appears on course for complete de-scheduling by the DEA, and the FDA is wrestling with how to regulate the CBD-based consumer products already hitting the market in many states. Amid this liberalization of federal law on hemp and CBD, it becomes easy to envision UC academics and UCCE personnel performing agronomic studies with hemp — and providing California hemp growers with the same sort of research-based knowledge that has long been available to cultivators of almonds, grapes and lettuce. Federal laws identify cannabis as one of the most dangerous drugs with no medical use, and its cultivation, possession, and distribution are criminally prosecuted. At the same time, many states adopt a different view admitting the medical benefits of cannabis and advancing decriminalization and legalization policies. As of 2019, 14 states and the District of Columbia have legalized cannabis for recreational use, and 35 states and the District of Columbia have legalized it for medical use. California’s cannabis policy makes for a special case. Owing to its large population and gross domestic product, California is the most prominent market of legal cannabis in the US . In 1996, California voters made history by passing Proposition, which legalized the medical use of cannabis. Twenty years later, in 2016, the state adopted Proposition 64, which permitted cannabis for recreational use with record rates of public support . Los Angeles and San Francisco lead by example in creating a supportive environment for the legal cannabis market. Their governments adopted social programs designed to lower the barriers for individuals with past cannabis convictions 1 and expedite the expungement of cannabis-related records.2 Nevertheless, it would be erroneous to assume that acceptance of cannabis arose with the same intensity across California counties and cities. Local jurisdictions have discretion over deciding whether to allow or forbid cannabis companies within their borders. At the moment, only one-third of California cities permit the distribution, cultivation, testing, manufacturing, or sale of cannabis, while the rest have passed ordinances forbidding any cannabis-related economic activities within city borders. This project is the first and the most comprehensive study of the unfolding process of cannabis legalization, which empirically addresses a set of interrelated questions. First, how is the legalization of cannabis for recreational use spreading across California cities? Second, what accounts for the uneven legalization of cannabis across California cities? And third, what does the case of cannabis legalization reveal about the relationship between legitimacy and legality more generally?