Tetrahydrocannabinol (THC), the primary psychoactive component of cannabis, causes psychomotor impairment and puts drivers at increased risk of motor vehicle collisions. Many jurisdictions have per se limits for THC, often 2 or 5 ng/mL, that make it illegal to drive with THC above the "legal limit". People who use cannabis regularly develop partial tolerance to some of its impairing effects. Regular cannabis users may also have persistent elevation of THC even after a period of abstinence. Some stakeholders worry that current per se limits may criminalize unimpaired drivers simply because they use cannabis. We conducted a systematic review of published literature to investigate residual blood THC concentrations in frequent cannabis users after a period of abstinence. We identified relevant articles by combining terms for "cannabis" and "blood" and "concentration" and "abstinence" and searching MEDLINE, EMBASE, PsycINFO, and Web of Science. We included studies that reported THC levels in frequent cannabis users after more than 4 h of abstinence. Our search identified 1612 articles of which 8 met our inclusion criteria. After accounting for duplicate publications, we had identified 6 independent studies. These studies show that blood THC over 2 ng/mL does do not necessarily indicate recent cannabis use in frequent cannabis users. Five studies reported blood THC >2 ng/mL (or plasma THC >3 ng/mL) in some participants after six days of abstinence and two reported participants with blood THC >5 ng/mL (or plasma THC > 7.5 ng/mL) after a day of abstinence. Blood THC >2 ng/mL, and possibly even THC >5 ng/mL, does not necessarily represent recent use of cannabis in frequent cannabis users.5 ng/mL, does not necessarily represent recent use of cannabis in frequent cannabis users.The aim of this study was to determine the pathogenic markers associated with Campylobacter infection in humans. A total of 104 Campylobacter isolates obtained from poultry and humans were examined for the presence of nine virulence genes and their ability to adhere to, invade and produce cytotoxin were defined using HeLa cells. The diversity of the Campylobacter spp. isolates was studied based on sequencing of the SVR-region of flaA gene. Altogether 45 flaA-SVR alleles were identified among 104 Campylobacter isolates of poultry and human origin. All Campylobacter isolates possessed flaA, cadF and racR genes involved in adherence. Accordingly, all poultry and human isolates exhibited adherence towards HeLa cells at mean levels of 0.95% and 0.82% of starting viable inoculum, respectively. The genes involved in invasion (iam and pldA) and cytotoxin production (cdtA, cdtB and cdtC) were also widely distributed among the human and poultry Campylobacter isolates. Significantly higher invasiveness was observed for poultry isolates (mean level of 0.002% of starting bacterial inoculum) compared to human isolates (0.0005%). Interestingly the iam gene, associated with invasion, was more common in human (100%) than poultry (84%) isolates, and the poultry isolates lacking the iam gene showed a marked reduction in their ability to invade HeLa cells. Moreover, virB11 was present in 22% of the poultry and 70.4% of the human isolates. Strains lacking virB11 showed a slight reduction in invasion, however in the absence of iam even the poultry isolates containing virB11 were unable to invade HeLa cells. The mean cytotoxicity of Campylobacter isolates from poultry and human was 26.7% and 38.7%, respectively. Strains missing both the cdtB and cdtC genes were non-cytotoxic compared to strains containing all three cdtABC genes, which were the most cytotoxic among the C. jejuni and C. coli isolates from both sources. No cytotoxic effect was observed in only 4% of poultry and 5.6% of human isolates.Low-moisture foods (LMF with water activity, aw less then 0.85) including pet foods and black pepper powder have consistently been associated with foodborne disease caused by Salmonella enterica. Increased heat resistance and prolonged survival at low-moisture conditions, however, remain major challenges to achieve effective inactivation of Salmonella in low-moisture foods. At low water activity (aw) conditions, heat resistance of Salmonella is greatly enhanced when compared to high aw conditions. This study aimed to quantify the effect of aw on the heat resistance of Salmonella enterica in pet food pellets and black pepper powder. Pet food pellets were inoculated with two strains of heat resistant S. enterica and black pepper powder was inoculated with a 5-strain cocktail of Salmonella. Both inoculated food samples were equilibrated at 0.33, 0.54, and 0.75 aw in controlled humidity chambers. Inoculated pet food pellets and black pepper powder in closed aluminum cells were heat treated at specific temperatures for selected times. The results showed that the Weibull model fitted well the inactivation data. At a specific temperature, the rate of inactivation increased with the increase in the aw from 0.33 to 0.75, and the 3-log reduction times decreased for Salmonella in both food samples with the increase in aw. Inaxaplin research buy Water adsorption isotherms of pet food pellets and black pepper powder at initial and treatment temperatures were developed to understand the change in aw during heat treatments. The change in aw during heat treatment was dependent on the type of food matrix, which possibly influenced the thermal inactivation of Salmonella in pet food pellets and black pepper powder. The quantitative analysis of heat reduction of Salmonella with respect to aw aids in selection of the appropriate initial aw to develop effective heat treatment protocols for adequate reduction of Salmonella in pet foods and black pepper powder.A new robust algorithm based on the explanation method SurvLIME called SurvLIME-KS is proposed for explaining machine learning survival models. The algorithm is developed to ensure robustness to cases of a small amount of training data or outliers of survival data. The first idea behind SurvLIME-KS is to apply the Cox proportional hazards model to approximate the black-box survival model at the local area around a test example due to the linear relationship of covariates in the model. The second idea is to incorporate the well-known Kolmogorov-Smirnov bounds for constructing sets of predicted cumulative hazard functions. As a result, the robust maximin strategy is used, which aims to minimize the average distance between cumulative hazard functions of the explained black-box model and of the approximating Cox model, and to maximize the distance over all cumulative hazard functions in the interval produced by the Kolmogorov-Smirnov bounds. The maximin optimization problem is reduced to the quadratic program. Various numerical experiments with synthetic and real datasets demonstrate the SurvLIME-KS efficiency.