Hemp Growing

From February to September 2021, we collected data on lobbying expenditures originating from the cannabis industry and its affiliates, from July 1, 2009 to June 30, 2021 . The Colorado Department of State dataset details payments to registered lobbyists, with information on funders who hire lobbyists , bill/rule titles and positions associated with payments, and lobbyist identifying information . To identify cannabis industry affiliates, we reviewed all funders in this dataset that lobbied on a list of 453 bills in fiscal years 2010–2021 that included the words “cannabis,” “marijuana,” or “hemp”. Using the CDOS business database, the Colorado Marijuana Enforcement Division search tool, and internet searches, we coded funders as cannabis affiliates if they a) held a cannabis business license, b) shared board members, owners, or investors with a cannabis company, c) disclosed members that were cannabis businesses, or d) would directly profit from cannabis sector growth . For each lobbyist employed by a cannabis affiliate we examined their other funders and identified additional cannabis affiliates using the same inclusion criteria. Because the CDOS dataset does not include lobbying payments made without a connection to a specific bill, administrative rule, or issue, we expanded the dataset by manually appending payments from cannabis affiliates in months where no lobbying was conducted for a specific bill/rule. Including these “retainer” payments allowed more accurate assessment of lobbying expenditures, because some funders make monthly payments to paymentslobbyists rather than hiring them on an ad hoc basis. Funders also make payments to lobbyists before and after legislative sessions for work during the session. The completed search yielded a list of 1703 monthly payments from 89 cannabis grow supply store affiliates with linked information on lobbyists they employed, positions on bills, and addresses. Each lobbying report available on the CDOS website included an “industry type” field where lobbyists provide a description of the funder’s business. We coded these disclosures as “transparent” if the name or description contained a reference to cannabis, marijuana, or hemp and “ambiguous” if it did not. Cannabis industry affiliates could be represented by lobbying agencies, lobbyists, and subcontractors.

Cannabis affiliates may pay individual lobbyists or pay lobbying agencies that funnel those payments to salaried lobbyists or subcontractors. Lobbying agencies sometimes list themselves as funders even though this practice was made illegal by the Lobbyist Transparency Act Lobbyist Transparency Act, 2019. We excluded reported self-funding because it was impossible to identify the underlying funder. To prevent double counting, we only included direct payments from cannabis affiliates and excluded payments to subcontractors and employees salaried by lobbying agencies. We reviewed cannabis lobbying expenditures in Colorado over time using Stata 16 and then qualitatively reviewed lobbying positions on proposed legislation. Our analyses assessed total cannabis lobbying expenditures and the share drawn from national sources, the extent to which expenditures were clearly identified as associated with cannabis, and alliances with other industries. We conclude with a case study of cannabis industry efforts to create cannabis consumption establishments. We selected this issue because legislation on the topic was introduced multiple times over the course of three years and under two gubernatorial administrations, allowing insight into changes in lobbying practices over time. We collected data from audio recordings of legislative testimony and floor debate, legislative histories, fiscal notes, and lobbying reports for all legislation dealing with cannabis consumption establishments available through the Colorado General Assembly and Secretary of State websites. We present a narrative description of each bill’s legislative history, including information from lobbying reports and demonstrative quotations made in public testimony that indicate cannabis industry influence in the policy making process. Many cannabis affiliates that appeared independent shared professional or personal ties. In 2019, 14 different funders lobbied in support of HB1090, a bill that allowed publicly traded corporations to own or invest in cannabis businesses and removed residency requirements.

These 14 funders were exclusively cannabis affiliates or lobbying agencies with known cannabis industry connections: LivWell, Buddy Boy, Dixie Brands, Gobi Labs, Gold Dome Access, Lightshade, Medicine Man, MedPharm Holdings, Native Roots, Natural Selections, TEQ Analytic Solutions, The Green Solution, Vicente Sederberg, and Wolf Public Affairs. All but Gobi Labs shared professional ties: John Fritzel was an owner of both Lightshade and Buddy Boy, and Andy Williams was the president of both Medicine Man and MedPharm Holdings . Representatives from Lightshade, LivWell, Native Roots, Vicente Sederberg, Medicine Man, MedPharm Buddy Boy, Dixie Brands, and Columbia Care were board members or donors for the Cannabis Trade Federation. Leadership from Medicine Man, MedPharm Holdings, Native Roots, Dixie Brands, TEQ Analytical Solutions, Vicente Sederberg and the chairman of the Marijuana Industry Group all sat on the Board of Directors for Colorado Leads, an alliance of cannabis businesses. Cannabis industry affiliates with an out-of-state address spent $802,983 between fiscal years 2010–2021 . Given that some cannabis businesses are multi-state operations with locations in Colorado and others use in-state PO boxes, this proportion is likely an underestimate. Immediately following adult-use legalization in November 2012 and prior to the creation of the recreational sales market in January 2014, the Washington D.C. based nonprofit Marijuana Policy Project dramatically increased its expenditures in Colorado. The proportion of out-of-state lobbying expenditures increased from 5.5% of lobbying expenditures in fiscal years 2010–2015 to 12.6% in fiscal years 2016–2021 . California-based cannabis organizations lobbying in Colorado increased from one business spending $14,492 in 2017 to five spending $153,220 in 2020. One cannabis affiliated organization each from Ontario , New York , and Oregon lobbied in Colorado, as well as two from Washington D.C. .The bill survived less than three months before indefinite postponement by the Senate Committee on Business, Labor, and Technology in March 2017. On the same day, SB184, which would allow local governments to permit private membership cannabis clubs and clarify the constitutional definition of consumption that is conducted “openly and publicly” was heard in the same committee.

Kevin Bommer of the Colorado Municipal League testified that the CML brought the bill to the legislative sponsors after it was initiated by the city of Trinidad. Renaissance Solutions, the Drug Policy Alliance, Terrapin Care Station, Denver relief Consulting, Schultz Public Affairs, and Pueblo County supported the bill while health groups including ACS CAN and the American Heart Association, hospital systems, and other local governments opposed. The House and Senate could not agree on amendments and the bill died in May. Onsite cannabis consumption establishments were considered again in the 2018 session through HB1258. This bill proposed “Marijuana Accessory Consumption Establishments” for existing licensees and was supported by Dixie Brands, LivWell, Good Chemistry, Renaissance Solutions, Medicine Man, Native Roots, Gold Dome Access, and the Colorado Hotel and Lodging Association. It was opposed by ACS CAN, local governments, consultants, Colorado Association of Police Chiefs, and Colorado Christian University due to indoor air quality concerns related to indoor use of electronic smoking devices, which were excluded from the definition of “smoking” at the time. However, the Southern Colorado Cannabis Council and My420 tours opposed the bill because it could eliminate party bus cannabis tours and did not create true social consumption establishments. After passing the House and Senate, the bill was vetoed by Governor Hickenlooper amid concerns that it violated the Colorado Constitutional prohibition on “consumption that is conducted openly and publicly” . A parallel bill, SB211, was introduced in March 2018 by Senator Marble and would have allowed smoking in “consumption clubs” through an exemption to the Colorado Clean Indoor Air Act. The bill was again supported by Renaissance Solutions, Inc. and opposed by the City of Colorado Springs, Denver Health, Healthier Colorado, the American Heart Association, Smart Strategies, the Colorado Association of Chiefs of Police, ACS CAN, and the Colorado Association of Local Public Health Officials. It died in the Senate Committee on Business Labor and Technology in April. Our findings suggest that after recreational legalization the cannabis industry expanded its lobbying activities and used tactics comparable to those used by similar industries seeking to promote consumption. The dramatic increase in cannabis industry lobbying expenditures over time mirrored growth of the cannabis industry following recreational legalization in November 2012, which also coincided with an increase in cannabis consumption. Funding originating from out-of-state sources also increased over time, suggesting the development of a national network of cannabis drainage system affiliates with similar interests. Legislators, public health advocates, and community organizers should therefore expect industry resistance to cannabis control measures from local and national sources as well as proactive industry efforts to promote consumption and profits through policy making channels.Colorado lobbyists characterized their clients ambiguously almost half of the time, meaning that cannabis affiliates could only be identified through lengthy investigation. These characterizations resulted in the appearance that many funders supported some proposed legislation, which may have created a false impression of a broad coalition. In reality these interests shared common owners, represented the same professional associations, and used the same lobbyists.

We also found some evidence suggesting that public relations agencies may have hidden cannabis industry funding by paying salaried lobbyists on the behalf of funders without identifying them. To improve transparency, the Colorado Sunshine Law could be strengthened by a requirement in C.R.S. 24–6–301 §1.9 that lobbyists disclose their client’s identity as a cannabis business or any cannabis affiliation they hold under the “industry type” field . To accomplish this, a revision of section 1 of the same statute may also be needed to eliminate the provision protecting clients from disclosure of “the names of any of its shareholders, investors, business partners, coalition partners, members, donors, or supporters, as applicable.” These changes would easily allow researchers and members of the public to identify cannabis clients as such using the CDOS website and facilitate improved legislative accountability. Cannabis affiliates used lobbyists focused solely on cannabis as well as sharing lobbyists with other industries including tobacco, alcohol, pharmaceutical, and gaming. Like other industries, the cannabis industry is likely to work with these business interests to further their own profits. Using the same tactics employed by these industries, cannabis industry representatives self-reported lobbying positions opposing clean indoor air laws, health warnings for pregnant women, and potency restrictions, while supporting investment, onsite consumption, and access to medical cannabis in schools. Cannabis industry funding peaked in 2019, which may be related to the change in state governor: Governor Hickenlooper was moderate on cannabis, vetoing several pro-cannabis bills, while successor Governor Polis had voiced support for the cannabis industry and was publicly supported by cannabis affiliates. The industry may have viewed his first year in office as an opportunity to pass pro-cannabis industry bills, including cannabis hospitality businesses, that had failed in previous years . In light of the sophisticated and well-financed influence campaign conducted by the cannabis industry, policymakers should push for stricter separation between the industry and the policy making process. Frameworks designed to prevent undue influence from other commercial determinants of health including the alcohol, food, and tobacco industries can dampen industry influence by creating firewalls between corporations and policymakers.

Example policies, including the guidelines for implementation of Article 5.3 of the Framework Convention on Tobacco Control , the World Health Organization’s Framework for Engagement with Non-State Actors , and the Office of Economic Co-operation and Development’s recommendations for preventing policy capture , could serve as starting points. These frameworks stand in opposition to the system of private interest institutionalism in Colorado which encourages the inclusion of all stakeholders and prompts regulators to make policies that synthesize stakeholder input. If formal mechanisms preventing cannabis industry influence in policy are not established, legislators should at least guarantee an equal voice to health advocates through balanced and accessible stake holding processes. Our research has limitations. For public relations and law firms who represented multiple interests, expenditures that were not explicitly delineated as being from cannabis companies were not included in our analysis as the origin of funds could not be identified. For this reason, lobbying expenditures are likely undercounted. Second, the exactpositions or intentions of cannabis industry affiliates on proposed bills could not necessarily be determined from the lobbying record; instead, where possible, we relied on legislative testimony. Next, the exclusion of salaries from lobbying agencies with ties to the cannabis industry to their employees may lead to an underestimation of the total influence exerted by cannabis interests. Finally, our description of lobbying expenditures did not include pro-bono industry lobbying activities conducted on behalf of cannabis affiliates.

The use of well water for cannabis cultivation, in comparison to other water sources, presents both potential threats and benefits for in stream flow. In upper reaches of small watersheds, streams are dependent throughout the summer months on subsurface water flows from the landscape into the stream. Well water extraction may reduce cold water inputs — limiting stream flow or, in extreme conditions, dewatering stream channels . The extent to which use of subsurface water affects stream flow and water temperature depends on the degree to which well water sources are hydrologically connected to streams. When wells are shallower and closer to streams, and when soil conductivity is greater, subsurface water pumping is more likely to directly capture stream flow. However, if wells are less hydrologically connected to streams, the effects of extraction will be attenuated, resulting in smaller-magnitude and temporally lagged stream flow depletions. With sufficient groundwater recharge in wet months, well water extractions may affect stream flow less than surface water diversions, which were previously assumed to be cannabis cultivators’ predominant means of obtaining water in the region.Such an analysis would incorporate information on well locations and depths and would consider the underlying geology and soil properties at cultivation sites . Meanwhile, the prevalence and distribution of wells relative to other water sources are influenced by broader geospatial characteristics such as topography and precipitation patterns. Understanding these issues will also be important for assessing the threats and benefits associated with subsurface water extraction.

Variation between counties in well extraction patterns demonstrates that, although subsurface water may be the most common source of water in North Coast cannabis cultivation, the availability of alternative sources may play an important role. Humboldt County watersheds included in this study consistently receive more average annual precipitation than do those in Trinity , Mendocino and Sonoma counties . This difference translates into more available surface and spring water in Humboldt County over the course of the growing season. The observation that fewer sites in Humboldt County report well use, microgreen rack for sale compared to other counties in the study, suggests that if surface or spring water is available, cultivators are likely to use it. Conversely, the potential necessity of groundwater use in counties that receive less rainfall holds particular importance in consideration of emerging areas of industry growth throughout California. Further analysis is needed to understand how likely cultivators are to rely on wells if other sources of water are available to them. The winter preceding the 2017 growing season was the wettest on record. It is important to understand how cultivators may source their water during years in which summer water availability is not as abundant. These findings suggest that cultivators may utilize wells both as insurance against surface water scarcity in the summer drought months and as a means of achieving regulatory compliance. The observation that nearly one-third of non-compliant sites reported well extraction indicates that use of subsurface water may be a common means to avoid water scarcity in the late growing season. While Northern California receives considerable seasonal rainfall, there is also significant spatial variability in rainfall totals and in corresponding summer flow persistence of small streams . Considering the ephemeral nature of surface water in many areas , the increasing frequency of drought due to climate change and cannabis cultivation’s consistent demand for irrigation water as crops near harvest , cultivators are strongly motivated to secure reliable water sources for the entirety of the growing season. Therefore, it is likely that water extraction from wells is a common practice for cultivators, beyond those seeking participation in the regulated industry .

Although cannabis regulations place no explicit restrictions on where water is sourced, those currently within or seeking to join the regulated cannabis industry will be subject to a restriction on diversions of spring and surface water during the growing season . This requirement is already in place for permits issued by the California Department of Fish and Wildlife and will also be enforced by the State Water Resources Control Board beginning in 2019. The data provided in this study indicates that, in order to meet the forbearance period requirement, cultivators may be more inclined to drill a well to achieve compliance than to develop water storage for spring and surface water. Determining cultivators’ capability to store the water they need for the growing season may shed further light on the likelihood that growers will seek subsurface water. If compliance necessitates drilling a well, it will be important to account for the impacts of this potential shift in cultivation practices. Successful protection of freshwater resources in Northern California will require a more complete accounting of where cannabis cultivators source their water and the amount and timing of water extracted . Study of cannabis as an agricultural crop has been notoriously inadequate, but data provided by the water quality control board’s cannabis program offers critical new insights into the water use practices of cultivators entering the regulated industry. In this initial analysis, we found that subsurface water may be much more commonly used in cannabis cultivation than previously supposed. Further analyses of cannabis cultivation’s water extraction demand, as well as of geospatial variation in water demand, may help elaborate the ramifications of this finding. Ultimately, a better understanding of cannabis cultivation’s water demand will be useful for placing the cannabis industry in the greater context of all water allocation needs in the North Coast and throughout California.People living with HIV and those at increased risk for HIV are at high risk for other health problems, including substance use, mental health issues, and socioeconomic vulnerabilities.The COVID-19 pandemic and resulting efforts to curb the spread of infection—such as stay-at-home orders and physical distancing mandates—and the resulting social isolation are likely to exacerbate these issues.

A survey of young adults in the USA found that immediately following the declaration of a state of emergency due to COVID-19, levels of depression and anxiety increased with high levels of loneliness and COVID- 19-specific worry being associated with higher levels of depression and anxiety. Factors found to be associated with pandemic-related depression and anxiety include being younger, being a racial/ethnic minority, or being diagnosed with a chronic disease.The pandemic-related increases in mental health issues may also extend to substance misuse. Prior studies of disasters, including the aftermath of the 2003 severe acute respiratory syndrome epidemic, found increased rates of substance use. Emerging data related to the COVID-19 pandemic seem to corroborate these findings, with one study noting a “surge of addictive behaviors” including food, shopping, and increased reported use of cannabis, methamphetamine, and opioids. Studies that specifically focused on men who have sex with men —including both those who were HIVpositive and at increased risk for HIV—found that changes in substance use and mental health were also associated with behaviors that not only increased the risk for SARS-CoV-2 infection—the virus causing COVID-19—but also had implications in terms of STI/HIV transmission.For instance, one study found that those who had sex with casual partners during pandemic restrictions were more likely to report using substances including alcohol as compared to those who avoided interactions with casual sex partners. Engagement in ongoing health care and prevention is especially critical to the health of vulnerable populations living at the intersection of multiple colliding epidemics of COVID-19, substance use, mental health, and HIV. In order to reduce the potential for SARS-CoV-2 transmission, many clinics stopped in person clinical encounters and switched to telehealth visits starting in March 2020. While telehealth outcomes in general — including among those who live with HIV — have been largely positive, telehealth has the potential to miss the most high needs and socioeconomically vulnerable patients.Beyond limited access to technology requirements for telehealth visits including a cell phone or computer and Internet connectivity , privacy concerns and the absence of confidential surroundings may also be an issue. In fact, one study found that even with an intervention to improve telehealth attendance, access to virtual medical care was still challenging among people living with HIV who were experiencing homelessness.Therefore, cannabis grow facility layout the objective of this study was to assess the impact of the COVID-19 pandemic on substance use, changes in mental health, and interruptions in mental health care among HIV-positive and high-risk HIVnegative men. Specifcally, we focus on cannabis use given the high prevalence of use, ease of access, and its use as the substance of choice to manage negative affect including anxiety and depression.

We describe the prevalence and correlates of interruptions in mental healthcare as well as factors associated with cannabis use for COVID-19 related anxiety and depression. We compare those who report interruptions in mental health care to those who did not experience these interruptions and hypothesize that those experiencing interruptions in mental health care will experience increases in depression and anxiety and will also report other negative health behaviors, including increased substance use and increases in sexual risk behaviors.Data for this study were based on those collected from participants in the mSTUDY — a National Institutes of Health /National Institute on Drug Abuse funded cohort of racial/ethnically diverse, HIV-positive, and high-risk HIV-negative MSM. Details of the mSTUDY have been previously described,but briefy, participants were recruited from two study sites in Los Angeles, CA, including a community-based organization providing services for the lesbian, gay, bisexual, and transgender community and a community-based university research clinic. Study enrollment started in August 2014, and cohort participation is ongoing. Eligible participants were between 18 and 45 years of age at the time of enrollment, identifed as male at birth, if HIV-negative, reported condomless anal intercourse with a male partner in the past 6 months, were capable of providing informed consent, and were willing and able to return to the study site every 6 months to complete study-related activities. By design, half of the participants were living with HIV, and half were substance using. Following the COVID-19 pandemic “stay-at-home order” in California, all in-person research activities were stopped on March 13, 2020, and remote study visits were launched starting March 31, 2020. For this analysis, we included all participant remote study visit data collected from March 31, 2020, through August 30, 2021 .The Institutional Review Board at the University of California Los Angeles approved the study, and all participants provided written informed consent prior to study participation. During in-person study visits, which occur every 6 months, participants complete a self-administered, computer-assisted survey and provide biological specimen for HIV testing . During the remote visits included as part of this analysis, no biological samples were collected. HIV status was based on testing done at the previous follow-up visit, which occurred 6 to 8 months prior for most respondents. Participants were sent an electronic link to the study questionnaire for each remote study visit, which was comparable to the survey used as part of the in-person study visits and included additional questions related to the COVID-19 pandemic. In addition to sociodemographic characteristics, the questionnaire collected information on current substance use, mental health, sexual risk behaviors, and COVID-19 experiences and the impact of the pandemic on overall health and well-being.The impact of the COVID-19 pandemic has been vast in terms of who has been impacted and broad in terms of how people have been affected. Our findings highlight the experiences of those living at the intersection of multiple colliding epidemics and vulnerabilities, including COVID-19, substance use, mental health, and HIV. In particular, our results indicate increases in symptoms of depression and anxiety with the highest levels noted in the most immediate time frame following the COVID-19 pandemic and a reversion to pre-pandemic levels within 17 months of follow-up. Our results also indicate changes in substance use linked directly to experiences resulting from the COVID-19 pandemic, with a high proportion of participants reporting cannabis use to cope with their heightened anxiety and depression. Furthermore, we find that interruptions in care due to the COVID-19 pandemic, particularly interruptions in mental health care, can link with negative outcomes along substance use and STI/HIV risk and underscore the intersectional vulnerabilities experienced by these individuals.

A prior genome-wide association study of DSM-IV cannabis dependence, conducted in the sample used in this study, failed to identify genetic variants at a statistically significant level . This has resulted in speculation regarding the biological underpinnings of cannabis use disorders; in particular, the question of whether common variation available in commercially available genome-wide arrays captures it . Aggregating the effects of all single nucleotide polymorphisms on commercial arrays might quantify the overall role of common SNPs as well as causal variants in linkage disequilibrium Table 1 Prevalence of individual DSM-IV and proposed DSM-5 criteria for cannabis use disorder in 3053 lifetime cannabis users of European-American and African American ancestry. When significant, this would indicate that heritable variation in the trait is at least partially captured by these SNPs in a highly polygenic manner. Applying this methodology, investigators have successfully attributed 23–51% of the variation in current smoking, major depression, schizophrenia and human intelligence to genetic influences . The present study uses a multi-pronged phenotypic and genomic approach to evaluate, respectively, the architecture and genetic underpinnings of DSM-5 cannabis use disorders, defined as a quantitative phenotype. Instead of relying on a diagnostic measure, we first utilize item response models to construct a factor representing liability to DSM-5 cannabis use disorders, while accounting for sex and ethnic differences. Second, we use this psychometrically constructed factor score in a genome-wide association analysis. Finally, we evaluate whether genome-wide SNPs and putative causal variants in linkage disequilibrium with them explain a significant proportion of the heritable variation in DSM-5 cannabis use disorders.The genotyping and quality control procedures applied to these data are explained in detail in earlier publications . In brief, DNA samples from 3988 individuals were genotyped on the Illumina Human 1 M bead chip by the Center for Inherited Diseases Research at Johns Hopkins University. As described earlier, 948,658 SNPs passed data cleaning protocols. No imputed data were used for these analyses. HapMap genotyping controls, duplicates, related subjects, and outliers were removed. For the current analyses, data on 3053 individuals reporting a lifetime history of cannabis use were used. Self-identified ethnicity was 2018 European Americans and 1035 African Americans.

We used MPlus to conduct exploratory and confirmatory factor analyses of the 12 DSM-IV/DSM-5 criteria in the same sample. Exploratory analyses were conducted in the full sample, while subsequent confirmatory factor analyses were conducted in African-American and European-Americans ,trim tray for weed separately by sex, using a multi-group framework. Initially, factor loadings and thresholds were constrained across the ethnic groups and across sexes. Individual sub-models were tested to determine whether allowing the factor loading and threshold for each criterion to vary across the groups resulted in a significant improvement in model fit. The model that accommodated all statistically significant differences was used to generate factor scores that were subsequently used for genome-wide association analysis.The sample used for analyses was restricted to those who reported at least one lifetime use of cannabis . These individuals are characterized with respect to the 12 individual DSM-IV/DSM- 5 criteria in Table 1. Prevalence of each criterion was higher in males than females for both ethnic groups, and males, regardless of ethnicity, were more likely than females to meet criteria for DSM-IV and DSM-5 diagnoses. However, several intriguing ethnic differences emerged. For both sexes, hazardous use, use of larger amounts or for a longer period of time and desire to quit or multiple failed quit attempts were differentially endorsed by EA and AA. EA men and women were more likely to endorse hazardous use and less likely to endorse using larger amounts or for longer than intended and failed quit attempts than their AA counterparts. In addition, tolerance, time spent using cannabis and the DSM-5 criteria of withdrawal and craving were more commonly reported by AA women than their EA counterparts—similar differences were not noted for men. The prevalence of DSM-IV cannabis abuse/dependence was higher in men compared with women, but no within-sex ethnic differences were noted. For DSM-5, cannabis use disorder was again more common in men than women, and there were no ethnic differences in men. However, AA women were more likely to meet criteria compared with their EA counterparts . Comparing the prevalence of DSM-IV vs. DSM-5 cannabis use disorders—within each group, very modest changes were observed. Decrease in overall prevalence was noted for EA, while AA women showed a slight increase and AA men remained unchanged. Examining the [95%] confidence limits for the point estimates, only the decrease in prevalence in the EA was statistically significant while the estimates in AA subjects could be equated across diagnostic classification scheme .An exploratory factor analysis of the full sample revealed that a single factor solution provided a reasonable fit to the data : 0.996, root mean square error of approximation : 0.054. While a 2-factor exploratory solution modestly improved these fit indices,the inter-factor correlation was 0.90. Hence, we proceeded with the more parsimonious single factor confirmatory analysis, which readily approximates item response parameters.

Confirmatory factor analysis of the 4 DSM-IV abuse, 6 DSM-IV dependence and the DSM-5 withdrawal and craving criteria revealed high factor loadings for all criteria except legal problems , which was excluded from further analyses comparing factor loadings and thresholds for each individual criterion across EA and AA males and females. The factor loadings and thresholds from the model allowing for statistically significant differences across individual items are shown in Table 2. Factor loadings and thresholds could not be constrained across the groups for hazardous use,interpersonal problems, withdrawal,using more than intended , repeated/failed quit attempts,time spent and physical/psychological problems . Factor scores that accommodated these differing thresholds and factor loadings were created for each of the four subgroups and used for genomic analyses.Individual signals did not surpass the Bonferroni corrected genome-wide significance threshold of p < 5 × 10−8. The results for the top 20 SNPs are presented in Table 3 . For the EA sub-sample, 11 SNPs on 17q23-24 appeared to be associated at nominal levels of significance although none surpassed the genome-wide threshold of 5 × 10−8.The top SNP, rs6504555, was an intronic variant in the bromodomain PHD finger transcription factor gene—a regional association plot for this region of chromosome 17 is shown inFig. 1, indicating a high degree of linkage disequilibrium across the associated SNPs. With the exception of rs11870068, the remaining chromosome 17 SNPs were in moderate to high linkage disequilibrium . In the AA sub-sample, results did not aggregate in any particular chromosomal region. The most significant SNP, rs4364205, on chromosome 3, was intergenic. Meta-analysis of the results from the EA and AA sub-samples did not yield a boost in statistical significance . This was evident from a comparison of results in the EA and AA sub-samples. Of all SNPs with p-values < 0.05 in EA sub-sample, only 5% had corresponding p-values < 0.05 in AA sub-sample. However, particularly for the SNPs for the EA sub-sample shown in Table 2, the direction of effect in the AA sub-sample predominantly concurred with the EA sub-sample.We sought to examine the phenotypic and genomic architecture of a continuously distributed cannabis use disorders factor, psychometrically derived from DSM-5 criteria, in samples ascertained for alcohol, nicotine and cocaine dependence.Analysis of ethnic differences indicated a modest reduction in the prevalence of DSM-5 cannabis use disorders, relative to DSM-IV, in EA. Genomic analyses, using a genome-wide scan, failed to identify SNPs that satisfied statistical thresholds for significance; however, gene-based association implicated genes on the q-arm of chromosome 17. A genome wide variance calculation revealed that 21% of the phenotypic variance in cannabis use disorders was captured by the available common variation on the genome-wide array, but this estimate had a large standard error and was not significant. We used the factor score as our phenotype for genomic analyses.

Incorporating withdrawal and craving, excluding legal problems and combining across DSM-IV abuse and dependence criteria, this factor embodies the ‘spirit’ of the new DSM-5 diagnostic scheme while not being encumbered by concerns that the threshold of 2 or more criteria for diagnosis of disorder is too lax . From a psychometric perspective, our results are consistent with the extant literature . For instance, despite our sample being ascertained for alcohol, nicotine and cocaine dependence, which inflated endorsement rates of individual criteria , our high rates of hazardous use were comparable with those reported for lifetime cannabis users from the general population as reflected in data from the National Epidemiological Survey of Alcohol and Related Conditions . Likewise, broadly consistent with numerous other studies, the DSM-IV abuse criterion of legal problems was infrequently endorsed and had a weak factor loading, affirming its proposed exclusion from DSM- 5. The overall prevalence of the remaining criteria, although much higher than in general population cohorts, supports the presence of a unidimensional construct across sexes and ethnicities. Craving and withdrawal, both of which have been added to DSM-5, performed well, with high factor loadings supporting their inclusion. Overall, trimming tray weed rates of diagnostic DSM-5 cannabis use disorders appear to be modestly lower than those for DSM-IV abuse/dependence, but only in EA, particularly men. This finding is highly comparable with epidemiological analyses of alcohol symptomatology in U.S. and with results from the 2007 Australian National Survey of Mental Health and Well being, which reported a decrease in the lifetime rate of cannabis use disorder from 6.2% to 5.4% when transitioning from DSM-IV to DSM-5 . In our sample, this decrease was uniformly attributable to individuals who endorsed hazardous use alone, which results in a DSM-IV diagnosis of cannabis abuse but not a DSM-5 diagnosis of cannabis use disorder, because it falls below the latter’s minimum two-symptom threshold. No differences were noted in AA men , and this is also not surprising. Individuals endorsing this criterion alone tend to be of higher socio-economic standing and tend to, overwhelmingly, endorse this criterion due to a history of drinking and driving . That socio-economic status may correlate with ethnicity is expected—in our data, 45.9% of AA participants reported a gross annual income of less than $20,000, vs. 15.4% of their EA counterparts. Upon examining gender and ethnic differences within classification version , the only significant variation was noted for DSM-5 diagnoses in AA women who were more likely to receive a diagnosis of DSM-5, but not DSM-IV cannabis use disorder, relative to their EA female counterparts. Intriguingly, also relative to their EA counterparts, they were less likely to endorse hazardous use but more likely to endorse numerous other criteria, with the exception of giving up important activities and use despite physical/psychological problems. This finding may be attributable to the larger number of AA women that were ascertained from the cocaine dependence study vs. other studies. Although this observation holds true for the men as well, and the prevalence did not vary across AA and EA women, it is possible that AA women from the FSCD study represent a high-risk group. For instance, when compared to the alcohol and nicotine dependence studies, AA women from the cocaine study were more likely to report lower household income and a greater likelihood of less than a high school education . Thus, this vulnerability might reflect environmental adversity rather than increased genetic susceptibility, and in any case, is accounted for in the genomic analyses by incorporating study sample and gender as covariates. From a genetic perspective, the single SNP analyses did not reveal any genome wide significant signals. This is likely because our sample is under powered, even with a quantitative trait, to detect single variants of modest effect size. Using GWA Power , we estimated power available in our dataset to identify SNPs of varying effect size. Power was 80% when an effect size of 0.01 was anticipated . Increasing efforts to amass larger samples with comparable cannabis-related data would afford greater power to detect variants of more modest effect size via meta- and mega-analyses. However, few current studies have DSM-5 criteria data. In this regard, factor scores such as ours may prove to be useful phenotypes as they can accommodate DSM-IV and DSM-5 based assessments of vulnerability to cannabis use disorders. In contrast,the gene-based analyses conducted with the EA sub-sample identified a cluster of genes, of varied function, on the q-arm of chromosome 17 that appeared to contain an aggregation of variants associated with DSM-5 cannabis use disorders.

Existing theories of student attrition, centered primarily on the undergraduate student experience, posit that attrition is influenced by individual, institutional, and social factors . Institutional factors include program characteristics, administrative policies, and academic requirements, and social factors include peer culture, faculty/staff interactions, and social integration. Individual pre- and post-matriculation factors include demographic characteristics, skills and abilities, goals and expectations, external commitments, and academic history. Largely missing from theories of student attrition are health status and health behaviors, particularly substance use prior to and after enrollment in an academic degree program. The relationship between alcohol and marijuana use and graduate degree completion is likely influenced by demographic characteristics. Both heavy drinking and marijuana use are more prevalent among college males than females , and substance use disorders are associated with being male, white, and unmarried . Having children is associated with a lower prevalence of substance use among both men and women . Demographic characteristics are also associated with graduate school completion, with burnout and attrition highest among women . Attrition is also more common among African-American/Black students , domestic students , and students enrolled in master’s degree programs . This study aimed to fill a gap in the literature by assessing the relationships between alcohol and marijuana use before and after graduate school enrollment and graduate degree completion. It is hypothesized that lower levels of alcohol and marijuana use both before and after graduate school enrollment are associated with graduate degree completion after adjustment for potentially confounding variables.The College Life Study is a longitudinal study of young adults who were recruited from a large, mid-Atlantic university. During the first stage of sampling, a ten-minute survey was administered to all incoming first-time, first-year students ages 17 to 19 that contained questions on demographic characteristics and tobacco, alcohol, and other drug use behaviors. During the second stage of sampling, the sample was stratified by race, gender, and substance use history. Students who had tried a drug or used a prescription drug non-medically at least once prior to college entry were over sampled. A random sample was chosen for longitudinal follow-up, and 1253 students completed a personal interview at baseline [Year 1 ; modal age 18].

Follow-up assessments were then conducted annually from Years 2 through 8 and then again in Years 10 and 12 through face-to-face interviews, self-administered surveys, and web based surveys. Follow-up rates were high,grow tent for sale ranging from 91% in Y2 and 73% in Y12. The university’s Institutional Review Board approved the study, and informed consent was obtained. Additional detail on recruitment methods and follow-up procedures can be found elsewhere . From the original sample of 1253 young adults, 541 participants enrolled in a degree-seeking graduate program at some point by Y10 of the study. Of these, 21 participants were excluded from analyses. Five of these participants were excluded because upon further examination of other assessment responses, they had listed graduate school enrollment by mistake, and one participant was excluded because information on their specific graduate degree type could not be identified. In addition, to ensure participants had adequate time to complete their degree, 15 participants who first enrolled in a doctorate or professional degree program in Y10 were excluded, giving a final analytic sample of 520 participants.Alcohol use was measured annually in Y1-Y12. To assess frequency of alcohol use, participants were asked, “In the past 12 months, on how many days have you drank any drink with alcohol in it?”. To assess quantity of alcohol use, participants were asked the number of drinks they had on a typical drinking day . Data on days used during the past year were used to estimate average alcohol use frequency for descriptive purposes. Marijuana use frequency was assessed annually in Y1-Y12 with the question “In the past 12 months, on how many days have you used any type of marijuana?” . Data on days used during the past year were used to estimate average marijuana use frequency for descriptive purposes. Past-month frequency of both alcohol and marijuana use were also assessed, but because of the high degree of correlation with past-year measures , only past-year variables were used in the analyses. For each participant, alcohol use frequency, alcohol use quantity, and marijuana use frequency were averaged separately for each of two time periods: before and after the first year they indicated enrollment in a graduate degree program. The mean for each of the six separate variables was used to capture variation in substance use during the pre- and post-enrollment periods, particularly because the before enrollment period included the undergraduate college years as well as the interim years after college graduation but before graduate school enrollment.Gender was coded by the interviewer in Y1 as either male or female. Race/ethnicity was measured in Y3, and response options included white; Black/African-American; American Indian or Alaskan Native; Native Hawaiian; Other Pacific Islander; Asian; and Hispanic, Latino, or Spanish. Participants could also write in a response or choose “Don’t Know/Refuse to Answer”. Given that the majority of the sample was non-Hispanic white, race was dichotomized into white and nonwhite. Marital status was measured in Y4-Y8, Y10, and Y12.

Participants indicated whether they were married, divorced, widowed, separated, in a civil union or domestic partnership, or never married. A dichotomous variable was created to represent whether or not participants were married at any point during Y4-Y12. The number of children participants had was measured in Y4-Y8, Y10, and Y12. A dichotomous variable was created to represent whether or not participants ever had children by Y12.Descriptive statistics were used to analyze the distributions of all study variables. Pearson correlation coefficients were used to analyze the relationships between all six alcohol and marijuana use predictor variables. A series of logistic regression models were fit to assess the relationships between alcohol and marijuana use and graduate degree completion. First, in Stage 1, separate logistic regression models were fit to analyze the relationships between each alcohol and marijuana use predictor variable and graduate degree completion while controlling for demographic and program characteristics. Second, in Stage 2, a best- fitting model was obtained by entering each of the six alcohol and marijuana use predictor variables into the model one at a time, retaining any predictor variable that was statistically significant and dropping those that were not significant. All demographic and program characteristic variables were retained in the final model regardless of significance. The Nagelkerke R2 value was used to examine the variance in graduate degree completion explained by the Stage 2 variables. A similar method has been used in prior work by the research team . SPSS Version 24.0 was used for all analyses, and the alpha level was set at 0.05.The majority of the sample was female and non-Hispanic white , with 42% of participants getting married and 14% having children by Y12 . About two-thirds had enrolled in master’s degree programs and 31% had enrolled in doctorate or professional degree programs, with Y5 as the most common year to begin graduate school. The majority of the sample completed their graduate degree by Y12.The majority of participants drank alcohol during at least one year before graduate school enrollment and after graduate school enrollment . Among drinkers, the average alcohol use frequency was about 75 days during the past year before enrollment in graduate school and 88 days during the past year after enrollment . Among drinkers, mean alcohol use quantity decreased from a mean of 3.9 drinks per drinking day before graduate school enrollment to 2.6 drinks per drinking day after enrollment. The typical quantity consumed for male drinkers was greater than female drinkers both before and after graduate school enrollment . Based on past-year data, it was estimated that about 35% of drinkers drank less than weekly and about 24% drank twice a week or more before graduate school enrollment.

After graduate school enrollment, 32% of drinkers drank less than weekly and about 31% drank twice a week or more.As seen in Table 2, marijuana use frequency among users was about the same prior to and after graduate school enrollment with a mean of about 40 days during the past year. Among those who used marijuana prior to graduate school enrollment, 56% used once a month or less and about a quarter used at least weekly . Among those who used marijuana after graduate school enrollment, 64% used once a month or less and about 18% used at least weekly . The correlations between the six alcohol and marijuana use predictor variables are presented in Table 3. There were moderate to strong correlations between the before enrollment estimates and the after enrollment estimates. Despite this statistical overlap, both before and after enrollment variables were retained due to their importance to the research question of interest. Alcohol use frequency before graduate school enrollment was strongly correlated with alcohol use quantity before graduate school enrollment and moderately correlated with alcohol use quantity after graduate school enrollment . To avoid the potential for multicollinearity effects on the statistical models, only the alcohol use frequency variables were retained for further analyses. There is prior evidence that frequency of alcohol use increases during the post-college period while quantity of alcohol use decreases ,indoor grow tent and alcohol use frequency has higher sensitivity and specificity in identifying alcohol-related problems than alcohol use quantity .Stage 1 results showed that, even after controlling for demographic and program characteristics, marijuana use frequency after enrollment was negatively associated with graduate degree completion . The best-fitting model included alcohol use frequency before graduate school enrollment and marijuana use frequency after graduate school enrollment, which were both significantly associated with graduate degree completion after being entered into a model together and with the demographic and program characteristics. Alcohol use frequency before enrollment was positively associated with the odds of graduate degree completion . In contrast, as marijuana use frequency after enrollment increased, the odds of graduate degree completion decreased . In the best-fitting model, gender, marital status, and first year of graduate school enrollment were associated with graduate degree completion.

Female students had almost two times higher odds of graduate degree completion when compared with male students, and married students had more than two times higher odds of graduate degree completion when compared with those who had never been married. In comparison with students who began their graduate degree in Y10 , students entering graduate school in Y5 , Y6 , and Y7 had significantly higher odds of graduate degree completion. 4. Discussion This study examined whether or not alcohol and marijuana use before and after graduate school enrollment were associated with graduate degree completion. Alcohol and marijuana use were moderate among participants in this sample. Results showed that more frequent marijuana use after graduate school enrollment was associated with decreased odds of graduate degree completion after adjustment for potentially confounding variables. This finding is consistent with prior research that has shown a relationship between frequent marijuana use and degree non-completion among high school and undergraduate college students . Marijuana use was less prevalent after graduate school enrollment as compared with before, which is consistent with research showing that marijuana use declines as young adults age . However, while past-year marijuana use frequency among marijuana users who completed their graduate degree declined from 40 days before enrollment to 35 days after enrollment, frequency among users who did not complete their graduate degree increased from 45 days before enrollment to 85 days after enrollment. There are several mechanisms through which marijuana use might affect degree completion. The first is through decreased academic performance, with underachievement cited as the most well-supported correlate of marijuana use . While little research has been done on the relationship between marijuana use and decreased academic performance among graduate students, existing evidence among high school and college students shows that frequent marijuana use is associated with academic unpreparedness , lower grades , and lower academic achievement . The relationship between marijuana use and degree non-completion might also be explained by the effects of marijuana use on cognition .

Mitochondrial dysfunction and oxidative stress are two factors that are thought to play a significant role in the development of PD. As seen in Fig. 1, rotenone and H2O2 both induced dose dependant decreases in cell viability in the TH1 transfected SH-SY5Y cells. The concentrations of rotenone and H2O2 needed to induce this change were higher than those noted in previous studies using the SHSY5Y cell line; this could be due to the transfection of TH1 within these cells incurring increased resistance to rotenone. This hypothesis is supported by our previous studies using the TH1 transfected SH-SY5Y cell line reporting an increased resistance to oxidative stress and treatment with 6-OHDA and H2O2.Cleavage of PARP-1 is commonly used as an index of apoptosis. In this study, treatment with rotenone and H2O2 both induced a dose dependent increase in PARP-1 cleavage indicating the occurrence of apoptosis. Interestingly while oxidative stress is thought to play a major role in cell death induced by both rotenone and H2O2, the two toxins had significantly different effects on TH expression. Rotenone induced an increase in TH expression within our SH-SY5Y cells, this is in contrast to previous studies that suggest rotenone treatment results in a decrease in TH expression in both animal models and cells.It should be emphasised, however, we measured TH protein only in the cells that were still attached to the bottom of the plate but not in the cells that had detached from the plates as these were removed with the media at the completion of rotenone treatment. Therefore, our results suggest that TH protein was increased only per remaining cell and not per total number of cells present at the beginning of the treatment. In contrast H2O2 had no effect on TH protein levels in the remaining cells, suggesting that while oxidative stress may play a role in rotenone induced cell death, the increase in TH seen was not induced by it. Rotenone is also thought to cause inhibition of the proteasome system,grow tent therefore it is possible that the levels of TH protein are increasing in these cells because breakdown and removal of the protein have been altered; however, this requires further investigation. Natural compounds with antioxidant and anti-inflammatory properties have become of interest with regards to PD as the current treatments are associated with harmful side effects.

Curcumin, cinnamon, hemp seed and Polygonum cuspidatum are all naturally occurring products that have been used in traditional Chinese medicine for many years.We found that pre-treatment of our SH-SY5Y cells with compounds isolated from these products did not have an effect on rotenone toxicity. This is in contrast to previous studies that have demonstrated the protective effect of curcumin against rotenone in SH-SY5Y cells.It should be noted that while both studies have utilised SH-SY5Y cells, our cells contain human TH1. Therefore, it is possible that the transfected TH1 and the increase in TH protein expression seen with rotenone treatment could be potentiating rotenone induced cell death and playing a role in our inability to protect against rotenone toxicity. As TH is the rate limiting enzyme in DA synthesis, it is possible that the increased TH protein expression in response to rotenone could have induced an increase in DA production. The increased DA could possibly accumulate within the cytoplasm of the cells and lead to increased oxidative stress, proteasomal inhibition and mitochondrial dysfunction that could be contributing to rotenone induced cell death. This hypothesis is similar to a popular hypothesis that suggests an involvement of hyper-activation of TH and DA production in early PD pathogenesis.Interestingly, the same compounds did display the ability to protect against H2O2 induced toxicity. In addition, all tested compounds also prevented the increase in PARP-1 cleavage seen with H2O2 treatment indicating a reduction in apoptosis and supporting the findings of the viability assay as well as the findings of previous studies that suggest the novel compounds possess antioxidant activity.Moreover a previous study has demonstrated the ability of cinnamaldehyde to modulate the release of catecholamines from a rat pheochromocytoma cell line,indicating this compound has the potential to not only be neuroprotective but may also further ease the symptoms of PD by promoting catecholamine release. While the in vitro antioxidant capabilities of these compounds have been demonstrated previously, this is the first study to demonstrate the neuroprotective properties of cinnamaldehyde, caffeoyltyramide and piceatannol glucoside in a dopaminergic cell line in response to H2O2. In summary, we demonstrated that the effect of rotenone on these cells is more complicated than just the induction of oxidative stress and suggest that perhaps TH may be involved. Curcumin, cinnamaldehyde, caffeoyltyramide and piceatannol glucoside successfully prevented H2O2 induced cell death, making this the first study to demonstrate the neuroprotective potential of these natural compounds in a SH-SY5Y cellular model of oxidative stress.

The combination of traditional and man-made fiber-reinforced composites provides many advantages in different areas of engineering and technology. The commonly used natural fibers in engineering fields are sugar palm, flax, sisal hemp, kenaf, and Abaca fibers. Incorporating natural fibers in high-strength synthetic fibers like carbon and Kevlar improves mechanical properties, namely, stiffness, toughness, moisture resistance. The properties of composite specimens have been enhanced due to addition of nanomaterials and lignocellulose fibers as reinforcement in composites.The properties of composites depend on the individual element characterization like matrix and fibers type, chemical properties of matrix and fibers. The hybrid reinforced polymer composite consists of natural and synthetic fibers with short fiber and random orientation and long fiber in mat form. In short and randomly oriented fiber-based composite, the sliced fibers are mixed in a fixed quantity of thermoplastic resin, melt mixer is used for homogeneous mixing. The product taken from the mixing chamber is a chunk form of fiber-based polymer composites. The small pieces of fiber/ matrix composites are obtained from different techniques: the pultrusion process and injection molding. The different research articles have been available based on the characteristic study of fiber-based composite by varying fibers and resins, fibers length. This type of chopped fiber-based composite fabrication can be used to reduce wastage because of small size of fibers, and also it is economical. The hybrid composite consists of two or more different fibers. Sid ika et al. found the experimental results such as impact, flexural, and tensile strengths of natural fibers, namely, Jute and Coir reinforced polypropylene resin composites. It has also been found from experimental results that variation of fiber content by weight fraction such as 25:75, 50:50, 75:25 in the overall loading fibers and the matrix content remains constant. Likewise, Ranjan et al. carried out research on hybrid fibers reinforced polylactic acid resin composite and found the results, namely, tensile, flexural, and impact strength. Additionally, the investigators observed that the strength of the Sisal/Banana fibers was reduced due to the presence of weak adhesive bonding between the fibers and polylactic acid. It creates lower-strength materials. Per z et al. reported the optimum strength and modulus obtained by varying the weight fraction of banana and coir fiber content in fiber-based composite. In addition, 15% of the coir fiber-reinforced polymer composite gives good impact properties, 10% of coir fiber reinforced polymer composites provide the best modulus and strength under the flexural and impact forces. Per z et al. reported a similar enhancement of results in impact strength.

Especially the coir fiber content contributed more to the improvement of impact properties in composite due to the following reason at higher fiber loading, it requires high energy to break the fibers or fiber pullouts high lingocellulosic content. The composite strength and modulus may be reduced at higher fiber loading due to the non-maintaining homogenous distribution of fiber content, which causes agglomeration in the region. The agglomeration region acts as a stress concentrated region, and it is responsible for the initial crack to the failures. The following are the disadvantages of the natural fibers, lower strength, weaker inter facial bonding, hydrophilic and hydrophobic nature of fiber and matrix, respectively. To enhance the mechanical properties of natural fiber reinforced polymer composites following ways can be adopted, i.e., fiber treatments, the addition of synthetic reinforcements, and coupling agents. The long fiber reinforced polymer matrixes have been made from prepregs or woven mats. The prepregs have formed by the melting and pressing fiber fabrics at high temperatures. The final form of long fiber reinforced polymer composite is formed by stacking the prepregs layer by layer. Kar dumen et al. reported the influence of stacking sequence on the mechanical properties by using woven flax and non-woven jute fiber reinforced on the polypropylene resin. They said additionally that the hybrid composite consists of non-woven jute covered by woven flax, which exhibits good strength. In contrast, the hybrid materials consist of woven flax covered by the non-woven jute, displaying good impact strength. Addition of the 10% glass fiber in jute fiber reinforced polypropylene composite has improved tensile and flexural strengths. Dan Mallam et al. fabricated the hybrid composite from the kenaf fiber and polypropylene terephthalate matrix; the two types of hybrid composite, namely woven interplay and interwoven. Amo g the two kinds of hybrid composite, the interwoven ply exhibit good tensile and flexural properties,grow tent complete kit while the woven interplay displays good impact properties. It is summarized from kinds of literature that the highest mechanical properties of the synthetic and natural fibers in Kevlar and Abaca fibers respectively, also very few works have been done in hybrid composites, however, no work has been carried out in the combinations of the Kevlar and Abaca.

Similarly, Glass and Hemp fibers also have specific advantages compared to other fibers. In this work, an attempt has been made to bring benefits of both synthetic and natural fibers in hybrid composites. The mechanical properties namely tensile, flexural, and impact testing, have been performed numerically and experimentally. Aba a, Hemp, Glass, and Kevlar fibers have been used to prepare the composite specimens. The hybrid composite materials consist of Glass/Abaca, Glass/Hemp, and Kevlar/Abaca.In this work, all four fibers, namely, Abaca, Hemp, Glass, and Kevlar fibers, were purchased in the form of long fiber. The thickness of the Abaca fiber is 0.35 mm, length is 200e300 mm, which is obtained from the stem of pseudostem of Musa sepientum. Yellowish Kevlar 49 grade with bidirectional woven fabric has been used, Hemp fibers, with the thickness of 0.08 mm and length of 15e35 mm have been used, Glass fiber in mat form, length of 6e12 mm and 0.01 mm diameter. All fibers were purchased from Vruksha composite, Chennai, Tamilnadu. The hybrid composites were fabricated by alternating natural and synthetic fibers into the matrix. In the present work, epoxy resin was used as a matrix material. The liquid resin is a colorless, highly viscous liquid, at 25 C the density and viscosity are 1.16 gm cm 3 and 900 cps, respectively. Harer is used to reduce the curing time, namely, Amine purchased from Bangalore-based company, namely, Naptha resin and chemicals. The natural fibers are purchased from Maruthi Peach Company, Tirupur district, Tamil Nadu, India. The synthetic fibers, namely Kevlar and Glass fibers, are purchased as yarns from Go Green products, Coimbatore, Tamilnadu, India, and weaved of fibers alternatively with 6.7 6.7 yarns per cm. The composite specimen is bidirectional, and the bulk and linear densities were used to calculate the cross-section of yarns. The cross sectional area of yarn is 0.015 cm2 . The area is calculated by dividing linear density by its bulk modulus. The density of the different fibers is listed in Table 1.The three different combinations of natural and synthetic fibers-based composites were prepared. The following loads were applied: tensile, flexural, and impact; then, results were reported. In each experiment, three times repeated and took the average value for the graph. A similar work has been carried out by Mohanavel et al., who characterize the mechanical properties of the hybrid composite, which consists of Glass, Jute, and Madar fibers. Also, they fabricated the hybrid composite with a similar type of stacking sequence, that is, the first and last layer was synthetic fibers, due to the lesser water-absorbing characteristics of the fibers.

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.The MR spectroscopy voxel was positioned in the right basal ganglia using the T1-weighted image.The caudate and putamen were the primary regions of interest.The voxel was positioned in the following way: left/right—the voxel was positioned so that it was as medial as possible,without containing any portion of the lateral ventricle,anterior/posterior—the voxel was positioned as anterior as possible in the caudate,without entering the anterior horn of the lateral ventricle,superior/inferior—the voxel was positioned such that the inferior portion of the voxel was as close as possible to the most inferior aspect of the putamen,and such that the superior portion of the voxel was approximately 3 mm inferior to the most superior aspect of the caudate.Fig.1 illustrates the voxel placement in a typical subject.confirmation of consistent voxel placement across subjects was achieved by segmenting and parcellating the T1-weighted image.

A high-resolution structural scan was acquired to position the voxel during data acquisition and to determine the tissue composition of the voxel through segmentation.The T1-weighted scan was processed using the standard Free Surfer pipeline for tissue segmentation and anatomical parcellation.Further details related to the Free Surfer processing can be found online,and in one of our previous publications.In-house software was used to compute the transformation matrix from the scanner coordinates to the FreeSurfer-processed T1-weighted image.A mask representing the spectroscopy voxel in the anatomical image space was then created using tools from the FMRIB Software Library,planting racks which was subsequently segmented and parcellated using the Free Surfer anatomical information.Thus,each T1-weighted voxel within the spectroscopy volume,was classified as either white matter,gray matter,cerebrospinal fluid,or non-brain,and was further parcellated into subcortical and cortical structures.This was done to confirm a consistent voxel placement across all subjects and to determine the basic tissue composition within the voxel.Further details of the voxel composition can be found in the results section below.Data were analyzed with the Statistical Package for the Social Sciences,version 19.Data were examined for normality in order to ensure appropriateness of parametric statistics.Univariate analyses of covariance were used to test group effects between the MJU individuals and the controls,with age and alcohol use entered as co-variates.Group and sex were both entered as between-subjects variables.Alcohol use frequency over the past 12-month period summarized by the PEI was used in the above model as the alcohol use co-variate.Two-way interaction effects between group and sex,when present,were examined further by running the model separately in males and females,or by examining sex effects within MJU individuals and controls.Finally,significant effects were re-evaluated by matching the MJU and control samples by age to verify that patterns remained significant with more stringent control over developmental differences that might otherwise impact the findings.There was no group by sex interaction for age or for IQ.

Marijuana users were college students of middle to high-middle socioeconomic backgrounds and most were free of a non-substance DSM-IV Axis I diagnosis.None were psychotic.Nearly all met DSM-IV diagnostic criteria for marijuana abuse or dependence.Use of other recreational drugs within the MJU group was limited,with no participants meeting DSM-IV criteria for abuse or dependence.One subject met diagnostic criteria for current alcohol dependence,and a small proportion met criteria for alcohol abuse.Compared to controls,alcohol use over the past twelve months use was found to be significantly higher in the MJU group,F = 43.93,p b 0.001.Marijuana users on average had a PEI score of 3.7,which corresponds to endorsing use of alcohol between 21 and 100 times in the previous 12 months.Controls on average had a PEI score of 1.5,which corresponds to endorsing use of alcohol between 1 and 20 times in the previous 12 months.When the sample is restricted to include only individuals aged 17 and higher,the difference in alcohol use remains significant but the mean value for control participants is slightly higher at 1.9.Thus,the amount of alcohol use endorsed over the past twelve months was entered as a covariate in analyses comparing metabolite concentrations between groups.The marijuana users reported that their age of first use of marijuana was 15.2 ± 1.2 years,and also reported smoking 9.8 hits per day during the past year.In addition,supplemental analyses were conducted to verify that female users did not differ from male users in their self-reported patterns of use,age of use onset,use of alcohol,or symptoms of psychopathology.Findings are presented in Table 3.The only group difference to emerge was that female users reported fewer symptoms overall of alcohol abuse/ dependence than did males.Otherwise,they did not significantly differ in variables that would suggest an increased frequency or duration of marijuana use,use of other substances,or presence of concomitant psychopathology.The spectroscopy voxel was consistently placed in the same anatomical location,centered in striatum,in both marijuana users and controls.

The voxel was primarily composed of gray matter,as determined by the Free Surfer parcellation procedure.The majority of the voxel composition was statistically similar between groups,with the exception of the pars opercularis,which accounted for less than 1% of the total voxel composition.The remaining 2% of the voxel composition was relatively variable.Moreover,these additional regions always represented very small amounts of tissue,and were not represented in all subjects.This study examined a cohort of college-aged heavy marijuana 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,sub irrigation cannabis there are relatively few human studies of brain-based sex differences associated with marijuana.McQueeny et al.showed adolescent girls had larger amygdalae and increased internalizing symptoms when compared to both control and marijuana using boys.Moreover,certain behavioral problems have also been linked to prenatal marijuana exposure in girls,but not in boys.Recent neuroimaging work suggests that young female users may be vulnerable to marijuana-induced alterations in brain volume,given suggestions of greater prefrontal cortex volumes and relatively poorer levels of executive function.Alcohol is similarly disruptive to females’ cognitive function and regional brain morphology,and it has long been recognized that females are more vulnerable to psychomotor sensitization with psychostimulant exposure.Preclinical data are somewhat stronger and indicate that female adolescents are particularly vulnerable to the effects of long-term THC administration on the CB1 receptor system in multiple brain regions,including the prefrontal cortex,striatum,and periaqueductal gray.A recent study of THC in mid-adolescent rats during the period of drug administration and following abstinence indicated greater sensitization of THC-induced locomotor depression in females versus males.Moreover,high doses resulted in increased anxiety-like behaviors during THC administration,particularly in females,although a general tendency is for females to experience greater anxiolytic effects of the drug.Glutamate is critically important in the neuroplasticity that accompanies the transition from drug use to abuse.Under conditions of extreme trauma or stress,its release is associated with neurotoxicity and cell death.Endocannabinoids block glutamate release under such conditions,which could lead to neuroprotection.However,the concomitant observation of high mIns levels argues against this interpretation.Given that mIns is considered to be a glial marker,high levels would be associated with gliosis as well as white matter injury as occurs in the context of neural injury.High mIns concentrations have been observed in early dementia,in frank Alzheimer’s disease,as well as in abstinent methamphetamine users,although this latter observation was in the frontal lobes.This pattern is intriguing given that deficits in learning and memory represent one of the robust areas of reported cognitive dysfunction in marijuana users.Although our data analyses do not suggest that female marijuana users in this sample are more vulnerable to cognitive impairments,this is a relatively young and high functioning sample.It may be that frank behavioral deficits will emerge more strongly in females over time as chronicity of use progresses.We hypothesize,too,that we may have observed altered NAA levels had we also measured frontal concentrations of each metabolite.Even though our statistical analyses do not show any significant effect of alcohol,it is important to consider the possibility of an underlying biological interaction between the two substances.Male marijuana users in this study had the highest levels of alcohol use,but did not show significant neurochemical alterations relative to controls.

Females showed the greatest apparent impact of marijuana use on Glx and mIns,but in the context of lower levels of alcohol use.These findings could suggest a neuroprotective effect in individuals who use both marijuana and alochol,as described by others.Alternatively,previous work has shown greater levels of Glx in the anterior cingulate of chronic alcohol users relative to controls.Considering this,taken together with the findings of the present study,it is possible use of the two substances together may drive metabolite concentrations to “normal” levels via opposing processes,as has also been suggested by others in the context of brain morphology.Differences in metabolic function in heavier versus lighter alcohol users can also impact the conversion of acetate into glutamate.It is possible,then,that the male marijuana users in this study who were heavier alcohol users as compared to females,demonstrated differences in glutamate metabolism,contributing to the observed sex difference.However this assertion is only speculative.While our data do not fully support these conclusions,the issue of alcohol use in the context of marijuana use requires careful examination in future studies.Sex but not group-related effects were also observed in total choline estimated concentrations.Independent of marijuana use,males showed higher estimated concentrations of tCho compared to females.