A test taker’s gamble: The effect of average grade to date on guessing behaviour in a multiple choice test with a negative marking rule

Background: Multiple choice questions (MCQs) are used as a preferred assessment tool, especially when testing large classes like most first-year Economics classes. However, while convenient and reliable, the validity of MCQs with a negative marking rule has been questioned repeatedly, especially with respect to the impact of differential risk preferences of students affecting their probability of taking a guess. Aim: In this article we conduct an experiment aimed at replicating a situation where a student enters an examination or test once they already have an average from previous assessments, where both this and previous assessments will count towards the final grade. Our aim is to investigate the effect of a student’s aggregate score to date on their degree of risk aversion in terms of the degree to which they guess in this particular assessment. Setting: A total of 102 first-year Economics students at the University of the Witwatersrand volunteered to participate in this study. The test used in this study did not count as part of the students’ overall course assessment. However, students were financially compensated based on their performance in the test. Methods: Following an experimental design, students were allocated randomly into four groups to ensure that these differed only with respect to the starting points but not in any other observed or unobserved characteristic that could affect the guessing behaviour of the students. The first group consisted of students who were told that they were starting the multiple choice test with 53 points, the second group were told they were starting with 47 points, and the third and fourth groups were told that they were starting with 35 and 65 points respectively. Results: We show that entering an assessment with a very low previous score encourages risk seeking behaviour. Entering with a borderline passing score encourages risk aversion in this assessment. For those who place little value on every marginal point, entering with a very high score encourages risk seeking behaviour, while entering with a very high score when a lot of value is placed on each marginal point encourages risk aversion in this assessment. Conclusion: The validity of MCQs combined with a negative marking rule as an assessment tool is likely to be reduced and its usage might actually create a systematic bias against risk averse students

Efficacy of λ-cyhalothrin, amitraz, and phoxim against the poultry red mite Dermanyssus gallinae De Geer, 1778 (Mesostigmata: Dermanyssidae): an eight-year survey

Dermanyssus gallinae (De Geer, 1778) is a major problem for the poultry industry worldwide, as it negatively affects virtually all kinds of rearing systems. Therefore, the control of infestation has become a routine process, and its economic cost is constantly increasing. Until now, most of the control strategies have relied on the use of synthetic chemical drugs, but their efficacy is often questioned by the emergence and diffusion of resistant mite populations. With this in mind, the efficacy of λ-cyhalothrin, amitraz, and phoxim has been verified by testing them against 86 mite populations collected from the same number of poultry farms in Italy from 2008 to 2015. Assays were performed according to the filter paper method using the recommended, half, quarter, double and quadruple doses. The results showed that phoxim and amitraz were the most effective acaricides (median efficacies 80.35% and 80.83%, respectively), but amitraz exhibited a sharp fall in its efficacy during 2011 and 2012, while phoxim maintained its high effectiveness up to 2015, when it dropped. The overall median efficacy of λ-cyhalothrin was 58.33%. The data also highlighted the importance of the use of the right concentration, as an increase in dosage was not always useful against resistant populations, while its reduction also diminished efficacy, simultaneously increasing the risk for the development of resistance

Prognostic factors in non-surgically treated sciatica: A systematic review

<p>Abstract</p> <p>Background</p> <p>When present sciatica is considered an obstacle to recovery in low back pain patients, yet evidence is limited regarding prognostic factors for persistent disability in this patient group. The aim of this study is to describe and summarise the evidence regarding prognostic factors for sciatica in non-surgically treated cohorts. Understanding the prognostic factors in sciatica and their relative importance may allow the identification of patients with particular risk factors who might benefit from early or specific types of treatment in order to optimise outcome.</p> <p>Methods</p> <p>A systematic literature search was conducted using Medline, EMBASE and CINAHL electronic databases. Prospective cohort studies describing subjects with sciatica and measuring pain, disability or recovery outcomes were included. Studies of cohorts comprised entirely of surgically treated patients were excluded and mixed surgically and conservatively treated cohorts were included only if the results were analysed separately by treatment group or if the analysis was adjusted for treatment.</p> <p>Results</p> <p>Seven adequate or high quality eligible studies were identified. There were conflicting but mainly negative results regarding the influence of baseline pain severity, neurological deficit, nerve root tension signs, duration of symptoms and radiological findings on outcome. A number of factors including age, gender, smoking, previous history of sciatica and heaviness of work do not appear to influence outcome. In contrast to studies of low back pain and purely surgically treated sciatica cohorts, psychological factors were rarely investigated.</p> <p>Conclusions</p> <p>At present, the heterogeneity of the available studies makes it difficult to draw firm conclusions about sciatica prognosis, and highlights the need for further research for this group of patients. Large scale prospective studies of high methodological quality, using a well-defined, consistent definition of sciatica and investigating psychosocial factors alongside clinical and radiological findings are recommended to identify prognostic factors in this population.</p

Multiple antimicrobial resistance among Avian Escherichia coli strains in Albania

In this study, 101 Escherichia (E.) coli isolates from broilers, laying hens and turkeys which had died from colibacillosis, collected from 37 intensive and rural farms in Albania, were tested for antimicrobial susceptibility toward 12 different molecules. The highest levels of resistance were observed for Erythromycin (E) (100%) Amoxicillin (AMX) (99.1%), Tetracycline (TE 30) (96.07%), Streptomycin (STR) (93.07%) and Neomycin (N30) (85.15%). Considerable resistance was also detected for fluoroquinolones. Moreover, 73.33% of E. coli resistant to at least one fluoroquinolone were also resistant to the two other fluoroquinolones checked. No evident differences were found between the E. coli from intensive and from rural farms. Multiple antibiotic resistance was expressed by all the E. coli tested. 23.63% and 17.39% of E. coli isolated from intensive and rural farms, respectively, were resistant towards all the drugs tested. These data would seem to indicate incorrect use of antibiotics on poultry farms in Albania

Modification of antiretroviral therapy regimen: Incidence and predictors in two major HIV/AIDS treatment centers in the Southwest Region of Cameroon

Background: The effectiveness of the first regimen of antiretroviral therapy (ART) is a major key to long-term success and sustainability of HIV treatment program. Aims: The objectives of this study were to determine the incidence rate, reasons, and factors associated with modification of initial ART regimen. Methods: A total of 502 patient files were reviewed. Modification of ART regimen was defined as either substitution or switch of a single drug in the regimen. Results: The total duration of follow-up was 629.8 person-years (PYs) over a median follow-up period of 37 months. About 92 (18.2%) of patients had their initial ART regimen modified, with a resulting incidence rate of modification at 14.6/100 PYs. Drug unavailability 49 (53.3%), drug toxicity 16 (17.4%), treatment failure 10 (10.9%), nonadherence 7 (7.6%), and concomitant condition 7 (7.6%) were common reasons for ART modifications. In the adjusted multivariate Cox proportional hazard model, the type of initial ART regimen (zidovudine/lamivudine (3TC)/efavirenz vs. tenofovir/3TC/nevirapine (NVP), aHR 4.78, 95% confidence interval [CI] [1.42, 16.12], P = 0.012), and duration on regimen (≤1 year vs. >3 years, aHR 4.11, 95% CI [1.02–9.22], P = 0.0001) were significantly associated with modification of initial ART regimen. Conclusion: Our findings indicate that the incidence rate of initial ART regimen modification was high. Hence, implementing better health systems to ensure a steady supply of drugs as well as early HIV diagnosis and ART initiation will reduce the rate of regimen change

Optical characterization of alternaria spp. Contaminated wheat grain and its influence in early broilers nutrition on oxidative stress

The aim of this research was the visual characterization and investigating the effects of Alternaria spp. contaminated wheat grains in the starter stage of broilers nutrition on productive parameters and oxidative stress. The research was divided into two phases. Bunches of wheat in post-harvest period of year 2020 was collected from a various locality in Serbia and Albania. In the first phase, collected samples were visual characterized by Alternaria spp. presence by color measurement methods. Gained results are conferred in the range of the color properties of grain color properties of Alternaria toxins. Wheat grain samples were significantly different (p 0.05). Alternaria spp. contaminated diet increased glutathione (GSH), glutathione reductase (GR), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) and decreased peroxidase (POD) and superoxide dismutase (SOD) serum levels, respectively. Built on the achieved results, it can be concluded that the wheat contaminated with Alternaria spp. in broilers nutrition negatively affected growth, decreased oxidative protection and interrupted chicken welfare in the first period of life