The last one is more labor intensive, but is often economically and ecologically sounds, and does not re-quire sophisticated technology, and thus is suitable for the farmers in developing countries and also for organic farming.Duke et al.proposed three approaches to select the sources of natural products for the discovery of potential herbicides: 1) to obtain pure compounds from other scientists, 2) to obtain biological material that has not previously been studied, and 3) to use ethno biological and/or chemical ecology clues. However, ethnobotanical knowledge showed better performance only in case of pharmaceutical, rodenticide and insecticide discovery, but not for phytotoxins. In this backdrop chemical ecology provides some important clues. They suggested two chemical ecology approaches to identify phytotoxic plants: a) allelopathic activity has been the most common approach; an example of this strategy is the discovery of sorgoleone from allelopathic sorghum species, b) the second approach is to examine compounds on that plant species have sequestered to avoid autotoxicity, for examples, artemisinin and hypericin . The allelopathic plants have been suggested as a viable option for alternative weed management under sustainable agriculture. These plants could be exploited in weed management through a number of processes.

For example, use them as cover/smother crops,rotational/companion crops , application of their extracts,vertical grow system incorporation of their residues or their different parts as mulch , application of allelopathic substances as natural herbicides, use of allelopathic plant ex-tracts with lower herbicide doses or development of allelopathic crop cultivars through breeding program. Xuan et al.demonstrated that allelopathic plant extracts performed better than synthetic herbicides to control weeds. They observed that Japanese alfalfa variety inhibited 80% total weed biomass and promoted 81% rice yield when compared with the control . In contrast, herbicide treatment suppressed 75% paddy weeds but increased rice yield by only 10%, and those for hand weeding were about 70% and 25%, respectively.As stated earlier, an increasing number of weeds are now gaining resistant to several synthetic herbicides. Therefore, it is much difficult to control them through synthetic herbicides. Allelopathic plants showed promising results in controlling those weeds. In Japan, Rotala indica showed strong resistance to some common herbicides. Application of alfalfa and rice byproducts at the rate of 1 2 t·ha−1 could completely inhibit the emergence of this noxious weed, and A. conyzoides, B. pilosa, G. pendula, L. glauca and Piper methysticum inhibited significantly R. indica at the same dose .Xuan et al.also reported that 70% 80% weed reduction could be attained through the incorporation of 1 2 t·ha−1 of strong allelopathic plants. Al-though the inhibitory activity of allelopathic plant biomass is dose-dependent, they suggested not exceeding the limit above 2 t·ha−1.

Otherwise, it will be labo-rious and costly.Therefore, it is very difficult to apply plant bio-mass in highland areas where water crisis exists. To overcome this problem many researchers currently focuses on allelopathic substances rather than the plant itself. They stated that if allelopathic substances with stronger activity on weeds are deployed as a tool for new natural herbicides development, the burden from plant residue application could be minimized.Sorgoleone, an isolated allelo-chemicals exudate from Sorghum root hair, has been characterized as a potent bio-herbicide. It is phytotoxic to broadleaf and grass weeds at concentrations lower than 10 μM. Post-emergent foliar application of Sorgoleone, at a similar concentration to labelled field rates of Atrazine , inhibited growth of most of the small-seeded broad-leaf weeds . Pre-emergence soil applications were also toxic to certain small-seeded weed species . The allele-chemicals of tomato e.g., tomatine and tomatidine also reduce the growth of weeds, pathogenic fungi at a satisfactory level .Several types of allele-chemicals for examples, phenolics, terpenoids, alkaloids, coumarins, tannins, flavonoids, steroids and quinines are involved in the phytotoxic activities of the allelopathic plants. Recently, a number of com-pounds extracted from higher plants, such as cineole, benzoxazinones, quinolinic acid and leptospermones, have been commercially applied in crop fields to control weeds such as Benzoxazinones and Quinolinic acid by BASF, Germany; Cineole as Cinmethylene by Shell, USA; Letospermones as Triketones by Zene-ca, Letospermones as Mesotrione by Syngenta AG. A brief description of the natural products commercially used in the crop fields is summarized in Table 1. Moreover, these herbicides are not quite enough to control a vast number of weeds, and also not effective to all weeds. Therefore, searching of new natural plant products effective for weed control is very crucial. Isolation and identification of new natural plant products might lead to the development of new natural herbicides.

In recent years, the condition of the soil in the fruit-bearing vineyards in the Republic of Dagestan has deteriorated.In many farms, the soil is turning into an erosive mass. And it does not allow to obtain a high yield not to mention biologically possible yield.The main reason for this is the absence of scientifically grounded system of keeping the rows of vineyards and in this regard, the wrong attitude to the soil as one of the most important substances is involved in the formation of the harvest.At the same time, farms, due to the high cost and their economic situation, can hardly afford the necessary quantity of fertilizers.Under the influence of running bodies of tractor units, moving many times over the season on the same track , soil at a depth of 4 5 cm turns into a mass, with a particle size of less than 0.25 mm-erosive mass . This erosion layer of soil by plowing moves in the lower rooting zone layers of the horizon, and from there better structured soil rises to the top. Later, under the influence of propulsion, this layer also becomes erosive etc. So every year, this process is repeated. As a result, on the one hand we have soil unstructurizing and on the other hand, there is a shortage of supply for the root system of plants.

To prevent degradation processes, by reducing the negative impacts of propulsion units on the soil, evaporation of humidity and providing the organic fertilizers, the system of keeping the rows of vineyards is being developed,and the materials of this article, are its integral part.One of the elements of this system is the weed vegetation growing in the inter rows of vineyards; it is used to create the grass layer but with roots cut. Weed vegetation is considered bad and they are trying to get rid of it.But in this work we seek to use it for the benefit of improving soil fertility. The herbal layer derived from it,prevents the direct contact of wheels units and sunlight with the soil, helps save the moisture in the hot period of time, and then,cannabis vertical farming is used as organic fertilizers for enriching its nutrients and disintegration. In our opinion, the vine crop productivity in the examined plots is low because the nutrition, air and heat regimes of soils are violated. As a consequence, the weak root system of the vine cannot provide the aboveground mass with the necessary amount of nutrients and water required for the entire period of active vegetation, especially,for formation the optimal harvest after the flowering.

Hot climate and water deficiency in the republic make soil conditions a major factor of successful growth, development and fruiting of vine.One of the main reasons that lead the soil deterioration to such deplorable state is absence of scientifically-grounded system of keeping rows of vineyards in proper order. And in this regard, our agronomic services don’t realize the importance of properly organized sequence of technological operations during crop cultivation and use of vine equipment which must be directed on taking into consideration the climate of the republic.And as a result we have wrong attitude to soil which is one of the most important substances involved in formation of the harvest. This process results in the gradual soil unstructurizing which is the main reason of low average crop yield in the republic .To prevent this process a system of complex measures is suggested. They must be agrobiological and technical operations aimed at creating favorable conditions for microorganisms in the soil and root system environment of plants.

These activities will lead to soil enrichment with nutrients and its disintegration and as a result, improve the productivity of crops and increase its fruiting term. Rice is the principal food for more than 50% people and contributes more than 60% and 25% to the cereals production of Asia and of the world, respectively, and it formulates nearly 30% of all the food being consumed in Asia . Globally, rice crop occupies 158 million hectares of the arable land.The global production and productivity of rice is 744.9 million tons and 4.71 ton per hectare, respectively . It is the major food item for billion residents of Asia and is the principal source of nutrition for many of the world’s densely populated countries such as China and Bangladesh . In fact, the approximate contribution of rice to the total calories being consumed is 30, 30, 50, 70, 60, 50, and 30% for China, India, Indonesia, Bangladesh, Vietnam, Philippines, and South Korea, respectively . It is reported that, nearly a half of the world population consumes rice as their principal food. Alongside this, the labour force required to produce rice provides livelihood especially to those belonging to the under privileged.

The antibacterial activity is moderate for Senna alata extract on Escherichia coli. These data are consistent with many previous results of the literature on the assessment of antibacterial activities of these herbal cosmeceutical plants. Omokhua et al.  reported the antibacterial activity of Chromolaena odorata on some bacterial strains and showed that extracts from this plant inhibited the growth of Bacillus subtilis, Bacillus cereus, S. aureus and E. coli . Fernandez et al.  showed that Tetradenia riparia was more active on the Gram positive bacteria strains . Cassia alata also showed potential antibacterial effect . Although certain crude extracts from studied botanicals have been shown to be inactive, fractionation studies are needed to determine the active fractions. Phytochemicals like phenolic compounds, terpenoids present in studied extracts, can act by interacting with the cell membrane or cell wall of microorganisms, leading to changing of the membrane permeability and therefore cell destruction or enter bacterial cells and promote the coagulation of their contents.

Therefore, phytochemicals can be used as natural antimicrobial in cosmeceutical plant extracts. Tannins are effectively known to possess interacting antimicrobial activities specifically for skin infectious diseases and diarrhea . Repetitive elements are present in large quantities in eukaryotic genome, both in coding and non-coding region. Among them the tandemly repeated DNA sequences of 1 – 6 bp are referred to as simple sequence repeats , sequence tagged sites  or microsatellites and resulted very useful for genetic marker development and genome application.Simple sequence repeats are codominant, abundant, multi-allelic, and uniformly distributed over the genome, and can be detected by simple reproducible assays . Traditionally, SSRs have been isolated from partially digested genomic DNA libraries and several thousands of clones were screened through colony/plaque hybridization using repetitive DNA probes. Later on several other methods have been used in order to decrease the time and cost invested and simultaneously increasing the yield of microsatellites. Today the increasing whole-genome sequences of many plant species provide sources for SSR mining in silico. Therefore,mobile grow system the low cost of in silico mining and high abundance of microsatellites in different sequence resources make this approach extremely attractive for the generation of microsatellite markers.

Recently, a whole-genome shotgun sequencing of the nuclear genome and transcriptome of hemp has been reported by van Bekel et al.  . This project provides the assembled draft genome and transcriptome of Cannabis sativa strain Purple Kush . The contig assembly contains 534.0 Mb without gaps and 786.6 Mb including gaps representing an estimated 65% and 96% genome coverage of the haploid hemp genome ~820 Mb . A total of 136,290 scaffolds were obtained from the whole-genome shotgun assembly and 40,224 from the transcriptome. Availability of hemp genome led to the possibility of in silico analysis of the genome for the identification of microsatellite which could be useful for cultivar identification, mapping and genetic diversity evaluation. Therefore, in the present study, we analysed the hemp genome and transcriptome sequences using several publicly available software programs with the objectives: a) to retrieve and characterize microsatellite loci from the genome and transcriptome, b) to develop and characterize a collection of SSR-markers for hemp in terms of frequency, information content, genomic distribution, and c) to assess their potential for diversity analysis in a reference set of hemp cultivars of different origin. Prostate cancer is the most commonly diagnosed malignancy in men and the second leading cause of cancer death in males. Most early tumours are androgen-dependent, thus depriving the tumour of androgens via surgical or medical castration  has proven to have significant effects at the initial stages of prostate cancer.

Despite the early efficacy of androgen ablation, advanced prostate cancer is resilient to such treatments and eventually relapses into a hormone refractory  disease, with devastating results on morbidity and mortality rates.The most effective treatment regime for patients with HRPC, docetaxel-based chemotherapy, can only improve the median survival time by 3 months . Therefore, effective treatment strategies against metastatic HRPC are urgently needed. The current therapies are not only successful in targeting differentiated tumor cells but also sparing the putative cancer stem/progenitor cells . Similar to normal stem cells, cancer stem cells  are thought to be quiescent compared with mature cancer cells . This property makes CSCs resistant to chemotherapeutic drugs, which mainly target actively replicating cells. In addition, two recent studies demonstrated that prostate CSCs are androgen independent  and may not respond to hormone ablation as mature tumor cells do.

However, this sex discrepancy may reflect heavier cannabis use reported among men relative to women, rather than a sex-specific sensitivity to this adverse effect of cannabis . More studies are warranted to research these findings. The main point from these six cases was that patients continued to have refractory nausea and vomiting with standard antiemetics. However, once given doses of haloperidol, the patients experienced a clinically significant improvement in their symptoms. And like the other cases, our patient received a multitude of other antiemetics without the relief of symptoms and it was only when she was treated with IV haloperidol followed by oral did her symptoms subside. Our report wasn’t without limitations. During this admission the patient received only one dose of metoclopramide. The attending physician made this decision based on the fact that the first dose didn’t relieve the patient’s symptoms and in previous admissions for gastroparesis but before the CHS diagnosis metoclo-pramide was effective, that this admission her nausea and vomiting were not due to gastroparesis.

Another limitation to consider is that the patient had some confounding conditions such as uncontrolled diabetes with her last A1C being 10.5 and associated gastroparesis. Even with these confounders we believe our patient experienced CHS because none of the typical medications used to treat gastroparesis such as metoclopramide or erythromycin eliminated her symptoms. In Nigeria, there has been a growing trend in the use of psychoactive substances. Current data indicate that drug use cuts across diverse groups, cannabis grow racks with high risk groups including males aged 10 to 29 years, law enforcement agents, commercial sex workers , commercial drivers and motor park touts. However, studies in this area are limited in North Western Nigeria. Several international studies highlighted the socio-demographic factors associated with psychoactive substance use. In Finland, in a nationwide survey of adult population, using a self-administered questionnaire, Kontula and his colleagues reported that in comparison with other European countries, drug use among the Finns was less prevalent, although there was a high prevalence of multiple drug use among the population studied . A survey in the United States showed that 37% of the population reported using one or more illicit substances in their lifetime .

Thirteen percent had used the substance in the past 12 months and 6% had used them in the month before the survey. More than 66% of the people aged 12 to 25 years had used a psychoactive substance, and more than 15% of the United States population older than 18 years of age had serious substance use problems. One United States population survey reported a 2% lifetime prevalence use of amphetamine. Those aged 18 to 25 years reported the highest level of use, with 9% reporting use at least once and 1% described themselves as current amphetamine users . In North Africa, cannabis resin  had been traditionally used by members of the Sufi sect, while in East Africa, the use of khat was reported to be common. Khat chewing was a social, culture based activity and some religious leaders were involved in the habit. High incidence of Khat chewing had been reported among university teachers, parents and other highly placed people in Ethiopia . In a nationwide study of psychoactive substance use among adults in five of the six geopolitical regions of Nigeria, Gureje et al. reported that the prevalence of alcohol was 58%, tobacco 17%, sedatives 14%, stimulants 2.4% and cannabis 3% among the population studied . However, the study was limited to self-report assessment of substance use among the respondents.

In a review of psychoactive substance related cases admitted to the Department of Psychiatry Ahmadu Bello University Teaching Hospital , Kaduna, in the 80’s it was reported that those aged 31 years and over tended to abuse alcohol, with majority being married  . The studies reported that the combined use of alcohol with cannabis was more likely than combining cannabis with amphetamines. Many studies of psychoactive substance use in Nigeria had been conducted on student populations. Students constituted a large portion of youths in Nigeria. Studies of drug use had indicated that the prevalence of drug use was high among the students population. The most commonly used psychoactive substances among university students had been reported to be salicylate analgesics , alcohol was next , stimulants, hypno-sedatives and cigarettes accounted for 35%, 18% and 11%, respectively.

The EI can be reduced by reducing herbicide rates or applying herbicides that have a lower EI; the environmental impact quotient can help determine the relative risk of various herbicide programs. The EIQ is a calculated potential risk based on physiochemical and toxicological properties of a herbicide. Toxicological data are gathered on the potential risk to the farm worker, consumer, and ecosystem, and include variables such as acute and chronic toxicity, toxicity to birds, aquatic species, and beneficial insects,as well as soil half-life, leaching potential, and the half-life of the chemical within the plant . The EIQ is then multiplied by the application rate to determine the EI.Farmers must ensure they are producing an economically sustainable crop in addition to herbicide efficacy, herbicide cost, crop safety, and EI.

The commercial release of DR soybean provides additional weed control strategies that need to be compared with traditional two-pass weed management strategies in soybean.The objective of this study was to evaluate herbicide programs for their crop safety, weed control efficacy,mobile grow system profitability, and EI in DR soybean produced with conventional tillage. A partial profit analysis compared the profitability of the herbicide treatments.The profitability of each treatment was determined by subtracting the costs of the herbicide and herbicide application from the gross economic return. Gross returns were determined by multiplying the plot yield by the average Ontario soybean price for the month of October in 2014 and 2015 . Annual herbicide costs were calculated based on the herbicide retail prices provided by AGRIS ,and the cost of the herbicide application was based on the Ontario Field Crop Budgets . Retail prices for some herbicide programs included in this study were not available, so those products were excluded from the profit analysis.

Profitability data were transformed using a square root transformation before analysis. There was no difference in partial profit among herbicide programs. All herbicide treatments produced similar partial profits. Glyphosate was the lowest cost weed management program and was 33% of the cost of the second lowest cost weed management program. The low cost of glyphosate combined with only one application cost contributes to why this treatment demonstrated the highest partial profit in this study. It is important to note, however, that if a single POST application of glyphosate was not applied in a timely matter, soybean would be exposed to a longer period of early-season weed interference, potentially causing greater yield losses which may result in lower partial profits. Additionally, infields where higher weed pressures exist, or where one or more difficult-to-control or GR weeds are present, glyphosate may not adequately control the weed population, which could also contribute to greater yield losses and lower partial profits. The development of glyphosate resistant weeds is a topic of concern; from a stewardship perspective, a herbicide program consisting only of glyphosate should be avoided to reduce the risk of selecting for GR weed biotypes.

Since there were no differences in partial profits between the glyphosate-only herbicide program and other two-pass weed control programs with multiple modes-of-action, it is recommended that a two-pass weed control program be employed. Alfalfa is a perennial, cool season, C3 forage species cultivated throughout the world and is primarily used for hay, pasture, silage, and cover crop . Alfalfa and its mixtures make most of the hay production in the US, with nearly 7 Million ha planted in 2017 . Alfalfa makes cropping system sustainable by reducing soil erosion, enhancing soil quality, and fixes atmosphere icnitrogen in the soil . As a perennial crop, alfalfa persists for multiple years, reducing the cost of establishment. Several biotic and abiotic factors pose challenges to alfalfa seed germination, emergence and seedling growth in the establishment phase. Weeds compete with alfalfa for light, water, and nutrients and consequently reduce yield and forage quality . Newly established stands are especially more vulnerable , but older stand sand frequently cut stands are also affected. Therefore, the first year of planting is very crucial in terms of crop establishment, biomass yield, and stand persistence of alfalfa.

Very slightly differences on plant growth occurred within a range of weed control strips from 50 up to 150 cm, for both plant height and stem diameter, according to the adjusted regressions. In this sense, the results are in accordance with those ones presented above, so that the weed control should be performed within a range strip between 50 cm and 150 cm.Now, analyzing the growth pattern of rubber trees specifically at 360 DAP and 720 DAP, in function of crescent weed control strips, the best adjusted equation was also an exponential rising to maximum model, showing a high significance, normal distribution of residuals, and constant variance of residuals , being well-appropriated to describe the plant behavior and satisfying statistical conditions. We observed that all the growth characteristics increased when weed control strips was extended, reaching a maximum value and then keeping constant, as observed by RGR. In addition, at the ending of 360 DAP and 720 DAP, any weed control strip allowed rubber trees to grow more than in a total weedy situation, independently of the strip width.In spite of that,cannabis grow tray the determination of the strip width required to an effective weed control without permitting a significant plant growth reduction was dependent on growth characteristics evaluated.

In this sense, at the ending of 360 DAP, the best weed control strip for plant height and stem diameter development was within 150 cm;however the best strip for leaf area and above ground dry mass development was within 50 cm and 200 cm, respectively. In general, similar results were observed at the ending of 720 DAT, however the best strip for plant height and stem diameter development was within 100 cm , indicating a slight growth recovery of plants growing under weed control strips within 50 cm and 100 cm. So, we suppose that weed control within a strip of 100 cm is sufficient to prevent weed interference on the establishment of a rubber tree plantation.A reduction in the availability of moisture and nutrients leads to reduced tree growth and survival . In our study, rubber trees in the weedy plots suffered the most from weed competition, exhibiting comparatively poor growth and stem diameter reduction . That reduction also affected the development of the leaf area and the above ground dry mass accumulation, impacting negatively on the initial growth and establishment of rubber trees in the two years after plantation.No studies were found on rubber trees, but in South Africa, eucalyptus crown growth of 10 cm can be attained in 41 days with 20% weeding or in 66 days with 0% weeding . Little et al. used the tree crown diameter as an indication of tree performance.

They observed a distinct exponential increase in median crown diameter with weed-free strip width and concluded that a 2-m strip width with no weeding at all in the 1 m between rows proved to be the best management strategy.Although trees grown with weed-free strips produced the maximum heights and stem diameters in our experiment, completely weed-free plantation is rarely necessary for normal tree growth . Such regimes tend to be expensive to maintain in terms of herbicide usage. In addition, lack of ground flora may be deemed to be aesthetically poor and make the soil more susceptible to erosion and leaching . In our experiment, all other inter-row weedy options reduced tree height and stem diameter, but not to an unacceptable degree. However, it is important to control weeds, avoiding competition between plants, until canopy closure begins and trees start to dominate or suppress weed growth . Safflower is an annual oil seed crop well adapted to the semiarid regions of the US Great Plains and Canada. Safflower possesses a deep taproot system, which can extend to a depth of 2 to 3 m into the soil, and is more tolerant to drought stress compared to other oil seed and small grain crops. Therefore, safflower would be a potential fit as a second crop in the dry land winter wheat-fallow rotations in this region. In 2015, Montana ranked second among the safflower producing states, with 13% of the total US safflower production . In the absence of weed interference, safflower grain yields can exceed 2000 kg∙ha−1 when grown after winter wheat . However, safflower is a poor competitor with weeds, and weed control is one of the major production challenges for successful adoption of this crop.

Articles published between January 2012 and October 2020 were considered if it had information regarding marijuana toxicity and medicinal properties. Further searches were conducted in google search engine by including general terms such as; marijuana toxicity, cancer, carcinogenicity, dangers, intake methods, throat cancer, smoking, cigarettes and cessation. Where there was need, the search outputs were saved in databases and the authors received notifications for searches that met the search criteria from science direct, PubMed, cross-ref and google scholar.There exists three major cannabis delivery techniques including inhalation, oral and topical, that have been frequently applied for use in different occasions with each method having various designed techniques that offer unique functions and results.Smoking and vaporization are the most prevalent ancient customary inhalation methods that are commonly used and involves the use of hand pipes, water pipes, paper rolls , hooker and shisha.

On the other hand, vaporization technique encompass the usage of vaporizers that steadily heat up cannabis herbs to temperatures high enough to extract THC, CBD and other cannabinoids but too low to expedite the release of harmful toxins such as benzene and toluene as well as odor,which are emitted thereby presumably, lowering the associated health risks throughout the marijuana smoking duration .This technique is widely used and differs from the traditional smoking habit,given that it does not involve combustion. For this reason therefore, vaporization method can be considered safer because it minimizes exposure to the potentially harmful marijuana smoke effluents that could be carcinogenic and toxic to the health of both active and passive smokers . Vaporized cannabis includes the use of vape pens, dab rigs and desktop vaporizers such as volcano medic vaporizer. In comparison, vaporized and smoked THC have similar pharmacokinetic profiles but on the contrary, vaporizers produce higher THC concentrations compared to smoked cannabis resulting to greater THC concentrations in blood, drug effects, mouth dryness and dry irritated eyes when same doses are smoked and vaped.For instance,marijuana edibles include drinks, foods and lozenges which have been infused with THC while tinctures include liquid cannabis extracts consumed by placing 3 – 4 drops under the tongue and gets immediately absorbed into the body system.

Consequently, marijuana products are classified as liquids , soft solids , and hard solids .A range of marijuana ingestion methods and their popularity is reported in Table 1. A good number of scientific researches have extensively identified the chemical composition of marijuana smoke and evidently noted that there exists a close association in chemical composition between second hand marijuana smoke,and tobacco smoke. The outstanding differences lies in the component concentrations variation with remarkably similar chemicals such as nitric oxides and aldehydes which have been proven to cause detrimental health effects .There is substantially little scientific research that has explored the chemical characterization of marijuana cigarette smoke but most of the available studies have focused on determining cannabinoids in marijuana smoke and reported it to contain most toxins, irritants and carcinogens commonly present in tobacco smoke . For instance, when smoked, marijuana releases more tar accompanied by substantially higher concentrations of carcinogens such as benzopyreneas compared to tobacco smoke, and consequently it has been classified as a secondary carcinogen that possesses approximately 50% to 70% more carcinogenic polycyclic aromatic hydrocarbons such as benzoanthracene, benzene and phenols in alongside toxic gases and reactive oxygen species that are 20 times higher in concentration than they are in tobacco .

Notably, these variations in carcinogenic compound concentration in marijuana enhance its probability of causing lung cancer in the same way tobacco does, which has been credited as the leading cause of lung cancer in various researches. Nevertheless,it can be presumed that smoking of marijuana is a precursor for respiratory disease and cancer similar to those caused by tobacco smoking, but on the other hand, there is minimal literature demonstrating that marijuana smoking causes cancer. Additionally, it has been suggested that marijuana smoke comprises of particulate matter that is harmful and carcinogenic when inhaled because it contains potent compounds such as volatile organics and aromatic amines .A range of toxic molecular compounds isolated from marijuana and their classification are presented in Table 2. Marijuana smokers are motivated by its psychotropic effects characterized by a pleasurable feeling, euphoria and relaxation which result in psychotic symptoms,cognitive changes, panic reactions and anxiety which have been reported as severe side effects .

Although we illustrated our model on individuals using an amphetamine-like psycho stimulant drug, the methods and rationale are readily extended to the study of marijuana. A key aspect of our model is that we focus on individual performance which allows the researcher to make a clinical assessment at the level of the individual. The model is applicable for researchers interested in using the CVLT or the memory test developed by the senior authors.We would like to note that our model can be used to test the claims of any plant based product.Claims have long been made about memory enhancing benefits of various plant-based products. While some claims have failed in scientific studies, curcumin has been shown in animal models to reduce depression by working on the cognitive impairments it causes, including effects on memory and learning .Flavinol in cocoa has been shown to improve memory in invertebrates , as well as spatial memory in rats .

Natural and synthetic memory supplements have a sizeable market, and sales were estimated to be $643 million in 2015, with the number of supplements available to consumers growing from 4000 to over 80,000 from 2004 to 2016 . Catechin-rich oil palm leaf extract supplements, for example, have been tested on young adults and resulted in increased short-term memory, processing speed, and spatial visual learning after one month .Approximately 15% of people over the age of 65 suffer from Alzheimer’s disease.The implications of studies where memory is improved by natural supplements denote an importance to sort through products with legitimate support for memory enhancement and potential for memory-loss prevention.The mathematical model posed by the authors can be used to do further research on the learning and memory enhancing properties of these plant derivatives in animals, as well as in humans.An area with an immediate need for research due to concern regarding the negative effects of plant-based products on memory is in the growing field of medical marijuana. In the United States, approximately30 states allow marijuana for medical purposes,although individual state regulations vary significantly.An increase in the number of medical marijuana users dictates a need to determine the possible side effects of using this substance.

Of particular concern are the possible effects of marijuana on neurocognitive functioning, including learning and memory .The senior authors’ model can easily be incorporated into various experimental designs and supplement traditional statistical tests. In the example shown here, we used a group design where drug free males and females were compared with males and females who regularly consumed an amphetamine-like psychostimulant drug. The model can also be used in “ABA” designs where participants are exposed to marijuana or other plant based products, subsequently exposed, and then no longer exposed.We recommend people who regularly use marijuana for medical purposes or other plant based products regularly test their memory for identification of early signs of impairment. For those researchers and clinicians who might be interested in modeling the learning curve, when monitoring memory in marijuana users, the senior authors developed an MS Windows application “LCMT” to help model the learning curve from raw learning data in the California Verbal Learning Test and other similar memory tests. This app is available on request from the senior authors.For those who want to constantly monitor the state of their memory on their own, the senior authors developed a Windows application for testing memory called “Memory Monitoring Tool”. This app allows long-lasting memory monitoring and might be used by marijuana users.

One drawback of using natural fibre composites in outdoor applications is their poor weathering properties.Natural fibre composites are finding increasing applications where they are exposed to weathering agents, which can cause changes in the micro structure and the chemical composition of these composites. These changes in turn can modify properties such as strength, modulus, impact resistance and fatigue behavior, which can have adverse effects on the service life of these composites. Therefore for long service life, the weathering phenomenon and how its effects can be mitigated must be understood. The two main sources of natural weathering are UV radiation and moisture. Natural fibers are not only good absorbers of moisture but they are also susceptible to UV radiation. Photochemical degradation by UV light occurs primarily in lignin which is also responsible for colour change .

For comfort body heat should be transmitted away from the body to the outer side of the clothing. This dry heat transmission occurs through conduction,convection and radiation. The mechanism of heat transmission through a fabric depends on its constituent fiber type, fiber arrangement, fabric bulk density,thickness, and the compressibility of the fabric structure . Here, an attempt has been made to compare the thermal behavior of various cellulosic fabrics including union as well as pure fabrics with 100% cotton. The results for comparative analysis of thermal insulation value are listed in Table 3. From the results it can be seen that fabric samples containing cotton indicate thermal insulation values on higher side as compared to pure fabrics of unconventional fibers presumably due to the structure of cotton fiber. Cotton fiber contains hollow lumen and twists causing more air entrapping in yarn.

Whereas, the fibers of hemp, linen and ramie are smooth, straight and contain almost no lumen . Moisture and water vapor transmission plays a very important role in governing the physiological comfort of apparel fabrics. This is related to the moisture vapor transmission through the fabric. This decides the extent of comfort the wearer feels in a sweating or similar condition. The results of moisture vapor transmission rate are listed in Table 3. The findings reveal that all the pure fabrics of unconventional fibers and their respective union fabrics have increased volumes of moisture vapor transmission as compared to the reference cotton sample.This behavior can be attributed to the hygroscopic nature of the fibers used. Also the fiber properties like diameter, rigidness and cross-section play an essential role in deciding the extent of openness of structure that will be responsible for better moisture vapor transmission. The higher values of MVTR indicates that these fabrics can transfer liquid moisture very easily and quickly from next-to-skin to the outer surface.

The findings compiled in Table 4 reveal that all the pure fabrics of unconventional fibers and their respective union fabrics have increased values of Accumulative one-way transport index as compared to the reference cotton sample. Generally fabrics which possess high OWTC values indicate that the liquid can be quickly transferred from the inner surface next to the skin to the outside surface. Also it will be spread quickly over the fabric bottom surface with a large wetted area. This large area spread of liquid help its quick evaporation into the environment. This behavior can be attributed to the hygroscopic nature of the fibers used. Also the fiber properties like diameter, rigidness and cross-section play a major role in deciding. Hemp fabrics show a relatively higher OMTC values and bottom spreading speed. This indicates that hemp fabrics can manage liquid moisture very efficiently. The sweat will quickly transmit to the outer side of such clothing and so will be evaporated by larger spreading in no time. The bottom water radius is also higher than top in fabrics containing hemp.

The fabrics containing linen falls in the next position after hemp in such type of overall moisture management. It may be observed that the bending and shear hysteresis of cotton and cotton rich union fabrics are significantly higher than other fabrics. The tensile resiliency values of hemp and ramie fabrics are also significantly higher than other fabrics. Tensile linearity of all cellulosic fibers is almost similar; the same is also observed in case of low stress compressibility. This actually falls in the logic that at low stress levels both tensile and compression results behave alike. From surface properties point of view, banana and linen fabrics exhibit significantly higher geometrical roughness due to higher hairiness and surface roughness of these two yarns. The THV of the fabric samples is estimated with the help of various primary hand values using the Kawabata-Niwa equations by KES system and the results are displayed in Figure 1.

It may be observed that the linen fabric gives the highest THV for summer and lowest THV for winter applications. This behavior is reflected in its constituent low stress mechanical properties where it found that both bending and shear hysteresis are significantly lower than other fabrics.The results also depict that almost all the fabric samples exhibit higher THV for summer applications as compared to winter due to obvious reason of their suitability as a cellulosic fiber predominantly meant for tropical and sub-tropical climate. The values of summer THV of all pure unconventional fiber based fabrics and their respective union fabrics are either comparable or better than100% cotton. This trend strongly advocates the possibility of unconventional fiber fabrics to be used as an apparel fabric for summers.Hemp fibre has widely been used in many civilizations. It has been reported that the earliest use of hemp was over 6000 years ago.

In a response inhibition study by Casey et al. , it was found that the volume of activation in the middle frontal gyrus is correlated with age, suggesting that this structure may be important in the developmental improvement of inhibitory abilities. Furthermore, several studies support that the development of the response inhibition circuitry continues to develop well into late adolescence. Given that the OPPS sample is comprised of young adults who on average have been smoking marijuana for 4.5 years , it is possible that their exposure to marijuana over those years may have compromised middle frontal gyrus development and thus, explain the dose dependent increase in activation. These results emphasize the importance of early education about the potential cognitive impact of early exposure to marijuana.Another brain region that showed a significant positive relationship between activation and amount of marijuana smoked was the right thalamus. The thalamus is included in various circuits including the frontal-striatal-thalamic and the cingulo-opercular networks.

The frontal-striatal-thalamic circuit has been found to support the development of inhibitory control and correlate with better performance on inhibitory tasks.The cinguloopercular network, which also includes the thalamus,among other brain regions, is thought to support response rate. Response rate refers to the ability to apply cognitive skills in a consistent and flexible manner depending on atask’s demands . A voxel-based morphometry study revealed that marijuana users had increased gray matter density in the right precentral gyrus and right thalamus compared to nonusers . The authors speculated that changes in one component of the brain, gray matter in this case, may be compensated for by changes in a neighbouring component, for example, gray matter displacement caused by a decrease of nearby white matter. Therefore,it is possible that the greater activation found in the right thalamus of marijuana users in the present study may be related to a change in white matter in other areas forming part of the inhibitory pathways. Consequently, compensation on such circuits may have occurred by increased activation of the right thalamus in order for users to keep up with the behavioral demands of the “Press for all except X” condition.

The inability to assess white and gray matter volumes in the present study is a limitation and future research is required.The present study also revealed a trend for a positive relationship between amount of marijuana smoked and greater bilateral activation in the inferior parietal lobe.More specifically,right parietal regions have been implicated in sustained attention , with neuroimaging studies reporting parietal activation during attentionally demanding tasks to be in the superior, rather than inferior, parietal lobule . Together, these results suggest that marijuana users may recruit additional parietal regions in order to properly sustain their attention during response inhibition tasks.Additionally, the parietal lobes are also part of the frontal-parietal circuit, which has also been associated with inhibitory control and working memory . This network has been found to continue to reorganize through adolescence, becoming more distinct and segregated from one another and further integrating long distance connections . As previously mentioned, the OPPS sample of users had been smoking marijuana since adolescence. Therefore, it is possible that the relationship between neural activation and marijuana consumption may be due to either a delay or to an altered development of such a network due to marijuana exposure during years where response inhibition circuits are still under development.

Another positively related trend from the present study was observed in the precuneus. This region is thought to have a role in error awareness and monitoring ,which is an important aspect of prefrontal cortex function since error detection allows for the correction and improvement of task performance . Support for this evidence is found in electrophysiological and lesion studies that propose that this region may be involved inevaluative functions such as monitoring behaviour . Moreover, Nagahama et al.have found that the precuneus is activated when external feedback shifts from “correct” to “incorrect” during tasks where subjects are required to alter stimulus-response judgments. Although during the Go/No-Go task, in the present study did not introduce an error awareness task, these findings may indicate that marijuana users need to work harder in order to monitor their response and be aware of errors during their performance. However, further testing with a response inhibition task that includes error awareness recognition should be carried out in order to confirm this result.Although other fMRI studies researching response inhibition in marijuana users have found greater activation in prefrontal regions including the dorsolateral prefrontal cortex , the present study provides further evidence that other brain regions of response inhibition circuitry may also be altered.