The introduction in 1998 by the USDA of the continuous Conservation Reserve Enhancement Program  provided crop producers with the opportunity to reestablish some of the structure and function of former riparian areas . CREP is a voluntary land retirement program intended to help agricultural producers protect environmentally sensitive land, decrease soil erosion, restore wildlife habitat, and safeguard ground and surface water. Where this program applies to lands bordering waterways, the stream must provide current or historical habitat for threatened or endangered fish species and must not be located above a permanent barrier to fish passage. The program also applies to any area with a completed agricultural water quality management area plan, as well as reservation and tribal trust lands. Eligible practices include planting and maintaining riparian forest buffers, filter strips, wetland restoration, fencing, off-site watering and others. Contracts are generally 10 to 15 yr in duration. CREPs are designed by the USDA-Natural Resources Conservation Service  and funded through the USDA-Farm Service Agency .

Technically, CREP projects are not considered ecological restoration, because native and non-native species are used , but are known instead as rehabilitated production systems The first CREP project in northeastern Oregon was established in 1999. After initial post-implementation evaluation by NRCS of the sediment filtering effectiveness of the seeded grasses and establishment success of shrubs, CREP projects are visited periodically to assure compliance with contractual agreements. Few systematic plant community, soil sampling, or soil erosion studies are conducted in RPS to evaluate project success in terms of structure and function, although numerous studies on larger ecological issues have used data gathered from these sites . For example, much of the research has been conducted as habitat evaluations of Conservation Reserve Program , e.g., . Systematic studies of individual CREP projects, particularly in the Pacific Northwest, are lacking,mobile grow system although a statewide evaluation was recently conducted in the state of Washington . The objective of this research was to conduct a multi-year vegetation observational study to describe plant community development in the Gerking Flat CREP. Target-nonnative species comprised significantly more of the vegetation composition than all other classes , during 2000 and 2001, but non target species increased substantially in 2007 and 2008 . This increase was predominately by Eurasian annuals typically found in disturbed semiarid and arid landscapes .

These species are exceptionally well adapted for invading disturbed areas where soil conditions and lack of seed sources reduce competition from native plants. Once established, these communities of invasive species tend to persist unless there is substantial management intervention . Management options in CREP are limited to light soil surface disturbance , mowing, burning, and limited herbicide use. The producer managing Gerking Flat mowed the site after the first year to control seed production from nonnative annuals. An attempt at disking part of the site was judged counterproductive, and the producer opted for burning some portion of the site each spring thereafter. Burning eliminated accumulating dead material, but apparently had no effect on slowing the increase in non target-nonnative species. In Mississippi, Greenfield et al.  were able to improve bobwhite habitat by disking or burning a 10 yr old CRP field, but the improvement was short-lived and plant community composition was unaffected. Disking, mowing, and burning are effective if applied at the appropriate plant phenological stage, i.e. before seed set.

But such timing is likely to interfere with critical wildlife use, such as nesting. Grazing has been proposed as a means of upland weed suppression , and can contribute to nutrient cycling advantageous to target species . However, grazing is restricted in most CREP contracts, and many of the CREP projects on the Columbia Plateau are managed by single commodity producers without the animal or managerial resources needed for grazing. The project on Gerking Flat met the basic objective of Table 4. Trees and shrubs found in zones 1 and 2  in a September, 2008, census. Species Number Willows  279 Pacific willow  Scouler willow  Coyote willow  Dusky willow  Booth’s willow  Woods rose  15 Snowberry  15 Red osier dogwood  5 Black cottonwood  4 providing ground cover, >90% in 2008, to conserve soil. A continuous canopy of willows now covers the channel in the lower one-third of the project. Increased root and stem biomass slows erosion, both within and outside the stream channels, and traps soil eroded from surrounding fields and borrow ditches .

The growth of the weeds near the mangrove forest can also bring in destructive herbivores such as locust, caterpillars and insect pests that feed on leaves. In the Niger Delta there are limited studies to address these questions. Therefore, this study is aimed at investigating the diversity of weed and other plant species found in sand filled mangrove forests, and to determine the concentration of some heavy metals in soil and plant. The objectives of this study are: 1) to determine the diversity index  and importance value  of the weed species 2) to determine the THC and heavy metal concentration in both soil and plant, and 3) to compare the THC and heavy metal concentration in plant and soil. The study area is an abandoned sand dump located at Eagle Island , directly behind the Rivers State University . The area has a warm and humid climate with two seasons, dry and wet seasons . The soil of the area is between sandy to muddy, and also whitish to dark brown in color . The area was once a mangrove forest, but was cut down to make way for sand mining five years ago. At the end of the sand mining activity the area was later abandoned to its fate. The company that operated the sand mine left the site with heaps of white sand still on the ground surface .

This abandoned sand became a plat form on which a variety of weed and other plant species grow over the years. These species are plants that naturally cannot grow in swampy soil but because of the conversion of the sand from swampy to sandy soil weeds do proliferate. Moreover, the site is surrounded by a river channel which brings in sediments and seeds of plants during high tide. At the edges of the sand dump are heaps of mangrove soils placed to prevent the entry of water during high tide. Heavy metal extraction followed the example of . Aliquots of 0.25 g of air dried sediment samples were weighed into a Teflon inset of a microwave digestion vessel and 2 ml concentrated  nitric acid  were added. The metals were extracted using a microwave accelerated reaction system  at 1500 W power , ramped to 175˚C in 5.5 min, held for 4.5 min,cannabis grow tent and allowed to cool down for 1 h. The cool digest solution was filtered through the Whatman 42 filter paper and made up to 100 ml in a volumetric flask by adding de-ionized water. All chemicals and reagents used were of analytical grade and of highest purity possible. Analytical blanks were prepared with each batch of the digestion set and analyzed  in the same way as the samples. The detection limit for the three metals analyzed in mg/l i.e. Zinc, Cadmium and Lead is 0.001, 0.001 and 0.002 respectively. Mangroves are habitat specific, and grow only in swampy soils.

This is because most mangrove species apart from A. aureum  cannot grow well in sandy soil because it has low salinity and conductivity . Mangrove swamp is one of the largest carbon sequesters in the world this is because of their air purification ability and high productive capability . Swampy soils have higher heavy metal load because of their exposure to oil spillages from oiling activities onshore and offshore. Pollution of the shorelines destroys swampy soils by reducing salinity and destroying microbes within the soil. A known characteristic of mangrove swamp is their ability to carry out decomposition , which has made them a biodiversity hot spot . But when human activities of deforestation, sand mining and urbanization degrade the soil it becomes difficult for them to carry out their function as host to numerous soil dwelling organisms. This enables opportunistic invasive species and weeds to come in to colonize the area . In this study, previous sand mining activity destroyed the swampy soil, and in its place sandy soil was deposited, which facilitated the proliferation of weeds .

The role played by weeds in this study area is not well known but need further studies. However, the result indicates that weeds present in the sand filled area absorbed the soil pollutants. This is shown by Figure 3, where weed concentration of THC and heavy metal was more than that of the soil. It shows that the weeds are acting as bioremediation agents. Mangrove swamp has hydrocarbon utilizing bacteria that degrade pollutant to a less harmful level The weed species from field observations are acting as host to pollinators such as butterflies, cricket, beetles and mosquitoes, to mangrove; this is a positive role by weeds . However, they can be detrimental to humans by hosting harmful insects and rodents. Field experiences had shown that most mosquitoes that reside in mangrove forest always go to roost on nearby weed and enter the mangroves to feed on animals, which is a negative role because of the proliferation of mangroves parasites in Africa .

Two parameters were adusted to develop the cforest models, mtry and ntree. The former respresents the number of random variables to use in each tree; the latter characterizes the number of trees. Model stability was tested using the following procedure  : 1) develop model using the default mtry  and ntree  values, 2) tabulate and review variable of importance rankings, 3) adjust starting seed  and rerun the model using the default mtry and ntree values, 4) accept model if variable of importance rankings are consistent between the first and second runs; if not proceed to step five, 5) increase ntree by 500 and rerun model following steps one thru four. The procedure was repeated until the variable of importance rankings were consistent between the first and second runs. The party package    of R was used to complete the classifications and to obtain the variable importance readings. For each date, two datasets were evaluated as input into the cforest algorithm: 1) twelve vegetation indices dataset and 2) sixteen band multispectral dataset.

Overall, user’s, and producer’s accuracies, and the kappa coefficient, were tabulated to compare accuracies of the classifications . Identical accuracy results were obtained for the vegetation indices and the multispectral data classifications for the June 30, 2014 dataset . Overall accuracy and the kappa coefficient were 90.8% and 0.878, respectively. User’s and producer’s accuracies ranged from 76.7% to 100%. The highest user’s and producer’s accuracies were obtained for the soybean class. The lowest user’s and producer’s accuracies were observed for the redroot pigweed and Palmer amaranth classes,cannabis grow tray respectively. For the September 17, 2014 dataset, the vegetation indices achieved higher classification accuracies than the multispectral dataset with the differences ranging from 0.7% to 3.4% for user’s, producer’s, and overall accuracies . Similar trends were observed in the classification accuracies of the vegetation indices and multispectral data. The best classification accuracies were achieved for the soybean class. Also, velvetleaf was tied for first for the producer’s accuracy. The lowest user’s and producer’s accuracies were observed for the redroot pigweed and Palmer amaranth classes, respectively. Variable importance rankings indicated that eight and nine of the twelve indices were important to the classification of the June and September vegetation indices datasets, respectively .

Its variable importance score was approximately 1.5 times greater than the second ranked vegetation index score. The multispectral datasets variable importance rankings are summarized in Figure 1. Shortwave infrared bands had strong to moderate variable importance rankings for the June dataset. NIR2, G, RE, and NIR1 bands had moderate to low variable importance scores. All of the spectral bands were important to the September 17, 2014 multispectral dataset classification model because their variable importance rankings were distinguishable from the zero line. The highest and lowest rankings were assigned to G and C bands, respectively. Finally, more trees were needed to obtain stable variable importance rankings for the multispectral datasets compared with the vegetation indices datasets . That aspect could be attributed to the multispectral bands datasets having more variables than the vegetation indices datasets, thus requiring more trees to be used for the stabilization process. Using vegetation indices as input variables for soybean and weed discrimination, cforest achieved classification accuracies that were equivalent to or slightly better than classification accuracies obtained with multispectral bands as input variables .

Kappa coefficients for the vegetation indices classifications indicated an almost perfect agreement  between reference and predicted data. Almost perfect to substantial agreement  occurred between reference data and predicted data for the June 30 and September 17, 2014 multispectral datasets, respectively. Errors for soybean and velvetleaf classes were attributed to the former being misclassified as the latter and vice versa. The cforest algorithm using vegetation indices or multispectral bands as input had problems in distinguishing between Palmer amaranth and redroot pigweed, suggesting combining them into one class. Consistently, indices derived with SWIR and NIR bands, the G and NIR bands, and G and R bands were considered important in separating the plant species. SIWSI1 and SIWSI2 were ranked in the top three for vegetation indices variables when evaluating both datasets .

Glyphosate is a relatively slow-acting herbicide and weed injury symptoms can take up to a week to appear and longer for complete plant death to occur. Therefore, growers could apply glyphosate to their crop within the critical period but still experience yield loss due to the slow-acting nature of the herbicide. If this is the case then the addition of another, faster-acting POST corn herbicide to glyphosate, applied as a tankmix, may increase the speed of weed control and decrease potential yield loss. The object of this study was to determine if the addition of a POST herbicide to glyphosate would improve the speed of activity and overall weed control thereby increasing glyphosate-resistant corn yield. Crop tolerance to the various POST tankmixes was also evaluated. Weed control must be implemented effectively without negatively affecting vine growth for successful establishment of grapevines in the Upper Midwest. Weed interference reduces grapevine vigor through competition for nutrients, space and water. Ineffective weed control after transplanting may delay establishment, flowering, and fruit production .

Successful weed control after transplanting and during establishment can result in a quicker return on investment by influencing the interval before a vineyard becomes profitable. Organic and synthetic mulches have been utilized for weed control for many years and in many cropping and ornamental situations -. Organic mulches have also been considered for vineyard weed control in the Eastern United States . However, mulch effectiveness as a weed control agent and its effects on vine growth have not been assessed in emerging viticulture regions such as North Dakota. Mulches not only act to suppress weeds, cannabis grow setup but may improve soil conditions by increasing soil water content, reducing soil erosion, and decreasing soil compaction . However, mulches may also alter the microclimate, soil properties, physiology, and phenology in plants These alterations in vine physiology could result in deleterious consequences for North Dakota vineyards. Synthetic mulches serve as an alternative to organic mulches as weed suppressants, however, their effect on soil conditions may vary. Soil temperatures and moisture contents recorded biweekly for one year under landscape fabrics varied more than those recorded under organic mulches . Glover et al. compared conventional, integrated, and organic apple production systems on soil physical, chemical, and biological properties . The authors stated that the organic method, which consisted of one year of bark mulch followed by two years of landscape fabric, resulted in lower soil bulk densities and generally improved biological soil properties compared to the conventional or herbicide weed control method.

Soil quality factors measured were slightly better in the integrated method, which consisted of one year of bark mulch followed by yearly herbicide applications. However, this would require the additional cost of the yearly applications. The objectives of this study were to compare organic and synthetic mulch efficacy to the standard herbicide weed control method used for the region and to determine how vine growth and winter hardiness after transplanting were influenced by weed control methods. An experimental vineyard was established at a North Dakota Experiment Station research site in Richland County, ND on July 25, 2007. The trial was planted on a Matador-Delamere-Wyndmere fine sandy loam . The experimental vineyard was arranged as a randomized complete block design with a split-plot arrangement and three replications. Main-plots were randomized within each replication and consisted of four in-row weed control methods  that spanned eight vines and covered an area of 9.6 m by 1.2 m. Sub-plots were randomized within each main-plot and consisted of one non-grafted cold-climate, V. riparia derived, hybrid grape cultivar  and three non-grafted cold-climate, V. riparia derived, advanced selections from two breeding programs . Experimental units consisted of two adjacent vines of a single randomly assigned cultivar. Plants were grown one year in 11.4 L containers prior to transplanting. Transplanted vines were kept clean cultivated and watered twice after transplanting. No additional irrigation was provided for the remainder of the experiment. Vines were trellised on a high cordon system. Vineyard rows were established in a north to south orientation. Plants were spaced 2.4 m apart in rows spaced 3.1 m apart. Row middles were maintained as bare ground with a combination of tillage and spot applications of glyphosate at 0.87 kg ae/ha for perennial weeds .

The weed control has been practiced since the time immemorial by manual labour and/or animal drawn implements, but these practices were laborious, tiresome and expensive due to increasing cost of labour. Weed management increases the cost of production and thus it is necessary to device such methods which could reduce not only the cost of production but also save time and labor. Among the weed control methods, the chemical control is the easiest one of the recent origins, and the most successful alternative method. Chemical weed control enables farmers to obtain higher yields per unit area with an over all lower production cost. The chemical method of weed control can provide us abrupt and promising results. Herbicides are a quick tool to control dense weed populations. Moreover, the control is more effective as the weeds even within the rows are killed which invariably escape, because of morphological similarity to wheat, during mechanical control. Selective herbicides reduce the need for hand weeding.

The effectiveness of herbicides is affected by time, rate and method of application. Out of total import of herbicides worth Rs. 2.2 billion, 63% were used on wheat alone during 2004 in Pakistan. Herbicides are frequently used to increase crop yield through effective weed control, but excessive and nonjudicious use of herbicides has posed many environmental and health problems . According to an international survey, over 295 biotypes of 177 weed species have evolved resistance to herbicides . These environment and health hazards and resistance development issues, therefore, have forced to develop some environment friendly technologies for weed control . Chemical weed control is more economical than conventional method . Reports are available on the efficacy of different herbicides in wheat . Puma Super 75 EW and Topik 15 WP are most commonly used narrow-leaved herbicides in the region but there are several reservations on the use of these herbicides as high application often involves the heavy expenditures and causes environmental hazard in addition to adverse affects on wheat crop. Similarly,cannabis grow tray low application could result the problem of low or no control of weeds and weed resistance etc. The herbicide use in Pakistan is not widely practiced as in the agriculturally advanced nations. The interest around the testing of graminicides indicates the problem posed by grasses whereas, the studies of Khan  showed synergistic response on combined use.

In another studies researchers obtained an effective control of weeds in wheat through chemicals . The objectives of the present studies were to determine the efficacy of different most effective and economical herbicides as compared to hand weeding in controlling weeds and to detect their effect on the yield and yield components of wheat crop under conditions of Pakistan. 2. Materials and Methods The experiment was conducted at Agricultural Extension Farm, Dargai, KPK during 2008-2009. The experiment was laid out in a randomized complete block design  design with five replications. Row to row distance was kept at 25 cm apart. All the herbicides were applied as post emergence as presented in Table 1. All the herbicides were applied with the help of a knapsack sprayer 20 days after sowing when the wheat crop was in the 5 – 6 leaf stage. Different herbicides rates were determined in terms of active ingredient or acid equivalent per acre treated, or as pounds or volume of commercial product per acre. Active ingredient indicates the amount of non-acid herbicide in a formulation. Acid equivalent indicates the amount of an acid herbicide in a formulation. Different weeds present at the time of herbicides application were Convolvulus arvensis, Avena fatua, Phalaris minor, Gallium aparine, Fumaria indica and Melilotus indica, etc. To avoid any misuse of the herbicides all the precautionary measures were taken to spray them successfully. The data were recorded on the parameters fresh weed biomass , weed control efficiency , number of tillers·m–2, thousand grain weight , biological yield  and grain yield . The prosperity of our people depends to a large extent on good wheat harvests.Weeds reduce the crop yield, deteriorate the quality of farm produce and hence reduce the market value of wheat. The control of weeds is basic requirement and major component of management in the production system.The chemical control method is one of the recent origins, which is being emphasized in modern agriculture.Furthermore, if the chemical control is tested in areas where wheat is intercropped with sugarcane, it may provide fruitful results .

Hybrid algorithms have focused on swarm intelligence, a recently recognized branch of artificial intelligence that studies complex self-regulating and decentralized systems’ collective behaviours. In 1989, the term swarm intelligence emerged as a set of algorithms by the two researchers Jingwing and Geradobeni and was used to control robot swarms . In addition to the IWO optimization algorithm to BA algorithm, a detailed solution can be found for optimization problems. Plant root structures are notoriously difficult to study. Root system architecture is defined as the spatial organization of roots and is crucial for normal root functioning. The RSA of a plant is affected by external factors such as water availability or nutrient stress. Roots have an innate ability to respond and adapt to external environmental factors, determining the plant’s RSA and giving insight into the soil environment . Phenotyping allelopathic root structures may provide insight into the plant’s ability to thrive and adapt to environmental stresses .

Allelopathic interactions involve plants detecting neighbors and adjusting the production and excretion of chemicals as a defensive reaction. Detection of competitor plants is presumed to be due to triggering compounds being released into the soil For instance, barnyardgrass releases allelochemicals into the rhizosphere, inducing increased production of allelochemicals in rice . Even when plants are segregated belowground and have no physical root contact, the detection of chemicals still occurs.Still,cannabis grow equipment the mechanisms and genetic origins of allelopathic signaling and reactions need more attention The genetic factors contributing to allelopathic root activity are still in the early stages of exploration; therefore, phenotyping provides information required for breeders to select traits associated with the high allelopathic activity . Combined manual measurements, imaging, and computer programs to measure small root parts contribute to retrieving this hidden information. Allelopathic rice lines exhibit shallow soil depth for the majority of their root mass .

Soil depth preference may be one characteristic of root structure architecture contributing to weed suppression . Information on root characteristics associated with wild rice types and the plant’s vigorousness is limited. It has recently been noted that there are characteristic differences between wild rice and cultivated rice. Weedy rice root systems express deeper, thinner, straighter, and less spread out roots than cultivated rice, which are more abundant . Research efforts to study root structures and how individual aspects relate to plant prosperity are slow, especially in allelopathic phenotypes, because root systems are difficult to observe without damaging the growing plant . Methods for studying root structure architecture are limited. Many methods are destructive to the roots system making data difficult to obtain accurately . Even the most minor root parts play a significant role in the plant’s productivity. In some cases, the root hairs make up nearly 77% of the root area, comprising most rhizosphere coverage, where the bulk of the plants’ nutrients is condensed.In addition to viewing difficulties, root architecture is manipulated by the environment and growing conditions. Root architecture data collected from growing plants in controlled environments is not always relatable to field conditions . Roots growing in an artificial medium should be trialed in a field setting similar to testing for allelopathy to compare results in different conditions.

Understanding the complexities of root architecture requires a combination of laboratory, field, and greenhouse methodologies . Laboratory phenotyping methods require propagating the sample plant in non-soil media like gels or on paper and supplied with nutrient washes. After growth, root formation features and characteristics are determined by manual measurements or with 2-dimensional imaging Soil extractions, imaging systems, or combinations of the two are standard field-root phenotyping techniques. The trench profile method, core break method, and shovelomics require soil cores to be cut and the soil removed from the roots to be measured . Soil core samples support root distribution approximation measures . The X-Ray Computed Tomography  images roots established in soil and is a non-destructive means of obtaining 3D root system images . Researchers at the University of California Davis performed X-Ray CT and noted that the method was not well-developed . Other reviews have highlighted the lack of standard procedures to separate soil and roots in the modeling process .

The nutrient sources include livestock handling areas, garden runoff, cropping and agriculture, erosion of cultivated land, urban sewage outflows and industrial wastewater among others . For the case of Lake Kyoga, gully erosion, wastes from human activities and livestock are the potential sources of nutrients  into the lake The generated wastes in Lake Kyoga catchment are untreated with high levels of pollutants like phosphates and nitrates . These nutrients create favourable conditions for Salvinia molesta infestation of Lake Kyoga. However, there has been inadequate study and management of S. molesta weed on Lake Kyoga as evidenced by the outcry of the people in Lake Kyoga basin from Salvinia infestation with its devastating environmental and socio-economic impacts . Hence an urgent intervention to control the noxious S. molesta weed in Lake Kyoga is required so as to fully use and exploit the resources of the lake. This study therefore determined the proliferation of Salvinia molesta weed at selected landing sites in Lake Kyoga as a result of anthropogenic influences and some physico-chemical parameters that favour the multiplication of S. molesta in Lake Kyoga in a bid to control the weed.

Dense swamps  comprising mainly of extensive mats of Cyperus papyrus L. surround the shores of Lake Kyoga and the numerous tributaries of the lake These wetlands create small bays close to the shorelines of the lake which support the establishment of S. molesta . The lake is surrounded by fishing villages with the people using boats for fishing and inland water transport hence there are several boat landing sites along the shores of the lake. Furthermore, mobile grow systems garbage from peoples’ homes and surrounding hotels are damped near the lake and cultivation is also done close to the lake. Therefore, in order to determine the extent of S. molesta coverage as influenced by the anthropogenic activities , four landing sites on Lake Kyoga namely; Waitumba at geographical coordinates , Masindi port , Acholi inn  and Kayei  were purposively selected for the study. The sampling points at Waitumba, Masindi port and Acholi inn landing sites were close to the shoreline of the lake while the sampling points at Kayei landing site were slightly offshore . The weed coverage was determined at or near waste sites , garden, boat dock and fishing areas in the landing sites. The coverage of S. molesta was determined using the quadrat method Six plots  each measuring 20 m by 20 m  were randomly set at or near the identified anthropogenic activities  in the landing sites . Four boats were arranged in the water at a distance of 20 m from one another to form the square plot  at each of the sampling sites.

Various shapes/figures  formed by the S. molesta mat on the surface of the water in the 400 m2 area were established and their dimensions measured using a tape measure. The area of each shape/figure  of S. molesta mat in the 400 m2 area was then calculated and the total area of the weed coverage in the 400 m2 area obtained by summing up the respective areas of the mats. Water samples were also collected and on-site measurements taken around the S. molesta mats in the study sites to determine the physico-chemical parameters that favour the multiplication of S. molesta or are compromised by its spread . Field work was done in one sampling period starting from December, 2015 to January, 2016When the authors investigated the growth rates of the weed in pH values between 5 and 8, increased biomass was obtained at pH of 6 and 6.5 compared to biomass at higher pH ranges. Furthermore, solid mats of S. molesta hinder gas exchange and often times build up carbon dioxide levels in the water column causing acidification of the waterway hence reduction of pH . The above findings justify the negative correlation of S. molesta coverage with pH in the present study. The thick S. molesta mats also lower the concentration of dissolved oxygen in water column  hence explaining the negative correlation of dissolved oxygen with S. molesta coverage. The negative correlation of S. molesta coverage with water flow rate obtained in this study is expected since S. molesta grows best in stagnant or slowly moving waters .

Furthermore, flushing usually moves infestations of S. molesta according to van Oosterhout . The lower coverage of S. molesta in Kayei and higher coverage in the other landing sites  can be respectively attributed to the offshore and shoreline locations of the sampling areas at the landing sites . According to Aloo et al. , aquatic weeds thrive most along the shores of water bodies. In addition, CABI  reported that S. molesta prefers small bays and inlets of dissected shorelines with less wave action. Furthermore, Wanda et al.  found out that S. molesta was well established along most of the shoreline in the central and western zones of Lake Kyoga. In addition to protection of S. molesta from wave action, the shoreline areas are also richer in nutrients than the offshore locations due to their lower depths.

Respondents are rewarded for participating in the study , but also receive rewards for refer-ring others to the research program. This approach is successfully implemented in the study of intravenous drug users , AIDS patients , men who have sex with men , sex workers , and studies of jazz musicians . When combined with controls to verify that a prospective respondent is a member of the targeted population, the collection of successive waves of respondents leads to “an equilibrium mix of recruits… that is independent of the characteristics of the subject or set of subjects from which recruitment began”, allowing for the calculation of unbiased population estimates.RDS operates under four assumptions: 1) respondents accurately describe the size of their personal network within the sample population; 2) recruitment of additional respondents involves random selection by recruiters from their personal networks; 3) friendship ties are reciprocal; and 4) recruitment operates as a Markov process in that the transition probabilities of the last individual recruited converges towards an equilibrium. In the process of achieving equilibrium, key variables of interest are monitored throughout the recruitment process.

Previous studies relying on RDS required interviewers, a physical location to operate from, printed recruitment coupons, and a coupon tracking system; while the face- to-face interaction helps to explain why referral rates are so high in these studies, significant limitations arose when assembling samples. Researchers, regardless of their constitution and efficiency, can only interview so many people in one day, interview locations are not available at all times, and respondents’ schedules do not always correspond with researchers’. Web-based RDS eliminates many of the logistical problems ,mobile grow system and tends to increase the speed of sample gathering .Wejnert and Heckathorn’s study of cross-racial friend- ship affiliations among college students demonstrates that large samples can be assembled in very short time periods if respondents view the study as important, the web interface is easy to use, and respondents’ personal networks contain one or more individuals who possess the targeted attributes . A primary drawback of web RDS, however, is that researchers are not able to meet with respondents face-to-face to confirm their status as attribute possessors or to weed out respondents who provide fake responses in lieu of recruiting real people —though Bauermeister et al. telephoned each prospective recruit to verify their existence and to protect from virtual ballot stuffing .

To counteract the selection of fraudulent respondents, Wejnert and Heckathorn suggest keeping recruitment rewards small and tracking internet protocol identification numbers so that multiple responses cannot emanate from the same computer . Bauermeister et al. encountered both recruiting and tracking issues in their study of young adult drug use. 22 initial seeds were recruited via Facebook, took an online survey, and were asked to enter the email addresses of two friends—automated emails were sent to prospective recruits from the researchers . Unfortunately, even with a $20 incentive for completing the survey and $10 incentives for each chain referral, only two additional respondents elected to participate in the second wave . The researchers altered their protocol: first, a link to the survey was emailed to the original seeds with instructions to forward the message to their friends, to “reduce” threats to a potential young adult’s confidentiality and privacy and reduce concerns that referral chains were being broken as a result of filtering of… email invitations” . There is no accounting of how successful this augmentation was, except that another alteration was required. This time, the authors “telephoned seeds and asked them about their experiences using the referral emails”, finding that most seeds “had never forwarded the email and had not told their referrals that they had invited them to participate” .

Referral restrictions were loosened, allowing participants to recruit up to five respondents through a variety of social media . This alteration, while successful in rapidly increasing the sample size, led to recruiters forwarding the unique recruitment announcements to multiple individuals in hopes of capitalizing on the increased incentives. While their approach yielded an impressive, diverse sample in a short amount of time compared to traditional RDS procedures , it is questionable that accurate RDS network calculations were achieved due to the use of individual IDs by multiple respondents—in other words, it is not plausible that recruitment wave origination was traceable after recruitment forwarding restrictions were liberalized. The authors mention that “survey data were checked daily to screen out duplicate and fraudulent cases ”, so it is possible that the RDS qualities of the network were preserved; however, this unknown without a presentation of the actual chain referral network .

A study found a positive association between having a psychological disorder and substance use disorder in Latino/a and Asian American adults from the National Latino/a and Asian American Study data, 2001-2003.A positive association between depressive symptoms and alcohol and illicit drug use has been reported in a study with a small sample size of college students . Higher rates of suicidal ideation/attempts and lifetime generalized anxiety disorders among female heavy drinkers have also been identified in a study with a small sample size .Until now, demographic risk factors related to substance use have been identified in Asian American studies. In most studies, males were more likely to have substance use and alcohol-related problems . Males were found to have a 12-month prevalence of substance use disorders eight times higher than females,but binge drinking was found to be comparable between males and females. Youth between 18 25 years old were at five times the risk of alcohol use compared to middle and older age adults.

In particular, Southeast Asian American adults between 25 44 years old reported alcohol use comparable to the national percentage, although a lower risk of substance use of Asian Americans has been previously reported.YM Lee and K Holm reported that among elderly Korean immigrants,a negative correlation existed between their income and depression scale score, which is consistent with findings from another study . Smoking is a predictor of binge drinking among Asian Americans . DE Toleran, PD Tran,B Cabangun, J Lam, RS Battle and P Gardiner also found that among adult males in the San Jose, Daly City,cannabis grow tent and San Francisco criminal justice systems, a positive correlation existed between tobacco and substanceuse. A limited amount of studies has investigated the prevalence and predictors of co-occurring alcohol, stimulant, and marijuana use among residential treatment program users, specifically Asian Americans. Therefore, the purpose of this study was to examine predictors of co-occurring alcohol, stimulant, and marijuana use among Asian Americans who receive residential treatment services. Descriptive statistics were used to examine sample characteristics, including frequencies and percentages for all categorical variables.

As preliminary analyses,Chi-square tests were computed between patients’ alcohol, stimulant, and marijuana use and all demographic and independent variables. Variables showing a significant relationship to alcohol, stimulant, and marijuana use were included in the final binary logistic regression analyses. Significance level was set at an alpha level of 0.05 in all analyses. The SPSS 21 version program was used to analyze data in this study. This study examined predictors of alcohol, stimulant, and marijuana use by Asian Americans with psychiatric disorders in residential treatment programs.The prevalence of co-occurring substance use was about 53% in Asian Americans with mental disorders. Binary logistic regression analyses revealed that male gender, older age, and depressive disorder predicted more alcohol use, but homelessness and schizophrenia predicted less alcohol use. Male gender, homelessness,and smoking predicted more stimulant use. Male gender and younger age predicted more marijuana use. Most findings from this study were consistent with those from other studies except for the association between age and alcohol use. In this study, older age indicated an increased risk of alcohol use, which is inconsistent with findings from another study that showed higher alcohol use with younger age . Due to characteristics of the study’s settings, the residential treatment programs being located in the San Francisco Bay area with a higher number of homeless people, about 40% of this study’s sample was homeless.

Findings from this study revealed that homelessness significantly increased the risk of stimulant use, which is consistent with findings from another study and well supported since people with unstable housing conditions are highly vulnerable to substance use further leading to aggravated mental symptoms .In this sample of Asian Americans, schizophrenia and schizo-affective disorder ere major psychiatric diagnoses, whereas depressive disorder and bipolar disorder were much less common compared to other race/ethnic groups from other studies.This may be related to underrepresented reports for and a lower mental health service utilization for their mood disorders among Asian Americans. In accordance with findings from other studies, this study also found a lower prevalence of substance use among Asian Americans .

To be able to participate, patients had to get certification from a certified practitioner and subsequently get the marijuana from licensed dispensaries spread throughout the state. Chronic pain was not initially one of the conditions recognized under the compassionate care act but after an outcry by the public, chronic pain was added as a qualifying condition for medical marijuana .Chronic pain was thus included in the list of the ten other qualifying conditions .The ten other qualifying conditions included Cancer, HIV infection, ALS,Parkinson’s disease, multiple sclerosis, damage to the nervous tissue of the spinal cord with objective neurological indication of intractable epilepsy, inflammatory bowel disease, neuropathies and Huntington’s disease. With the legalization of medical marijuana in most states and recreational marijuana in some states,more studies are needed to assess the efficacy of marijuana as a means of addressing chronic pain, cachexia/wasting syndrome, glaucoma among others .

As part of efforts to improve healthcare and improve the data we have on the use of medical marijuana, we conducted a study of the efficacy of medical marijuana for chronic pain in an outpatient chronic pain clinic setting. The study was carried out in an outpatient pain clinic setting in New York from October 2018 to May 2019.Selection criteria: All patients who were on medical marijuana and were returning for their follow up visits between the period October 2018 and May 2019 were offered the survey. Patients under the age of 18 were excluded from this survey. Survey answers were collected in the clinic, cannabis vertical farming via secure email and phone calls. We had a total of 21 participants who responded to the request.The study qualified for exempt status. As defined in the federal regulations :minimal risk standard was applied: ‘the probability and magnitude of harm or discomfort anticipated in the research are not greater in and of themselves than those ordinarily encountered in daily life or during the performance of routine physical or psychological examinations or tests.Even though clinical data supports the use of marijuana for pain,there is still not much known about the efficacy, dose, route of administration,or the adverse effects .

Medical marijuana offers numerous benefits such as better management of pain as demonstrated by the participants of this study. The responses in this study showed a 50% reduction in pain levels after use of medical marijuana .Other benefits that we observed include decreased levels of anxiety, increased appetite, decreased migraines, reduced swelling, improvement in mood as well as an increased quality of life as reported on the surveys. The improvement in sleep evidenced in this study is significant as poor sleep worsens overall pain scores and also interacts negatively on aspects of health including mental health. Marijuana is also relatively non-addicting, and few withdrawal effects have been reported with perhaps one of the most significant benefits of medical marijuana being the reduction in opioid overdose mortality rates .There are limitations to this study, the first being that the patients who responded were patients already on medical marijuana and returning for follow up visits and hence they already had benefit from the medical marijuana. This is also a survey as opposed to a case controlled study with an interventional study group. Marijuana remains a federal class 1 drug which limits such studies. There is therefore lack of longitudinal studies evaluating the effects of chronic marijuana use. These past few years have witnessed the speedy development of scientific techniques and an addition in the standard of living of human.

However, these developments have their disadvantages. Fossil fuels were running out and there is insufficient space for our garbage. In order to reduce the environmental load generated from the disposal of used plastic products, significant attention has been placed onbiode gradable resin. This resin can be completely resolved into water and carbon dioxide by the action of the microorganism, when it is disposed of in the soil.More over, there are no emissions of toxic gases during incineration. The application of biodegradable resin has been restricted due to their relatively lower strength compared to conventional plastics such as POM and nylon.Resent years, because of their extensive use in many diverse fields, plastics, including FRP products have become indispensable to our life. However, the primary raw material used in plastic production is petroleum and there are strong social and economic pressures to conserve petroleum resources.Furthermore, because FRP wastes are non-flammable, they must be disposed of in landfills after use, and this contributes to high environmental loads.