Statistical Modeling and Analysis of Online Examinations in Covid-19

In this paper, the authors build a model that predicts the grade point from a collection of independent variables including student characteristics and exam marks achieved in four marketing management courses using data from four courses. The data from four courses in marketing management, for an off-line class in a master’s in business management program taught in 2019 and the same set of four courses in marketing management taught to an on-line class in 2020 was taken. Although the number of students enrolled was almost equal, and the courses, despite being offered a year apart, were nearly comparable in structure and content, the teaching and assessment for 2019 was conducted offline, whereas it was conducted online in 2020. In the set of four courses offered in 2019 using the offline mode, the exam was proctored and offline but for the same courses offered in 2020, the final exam was also proctored but online. The authors predicted that if exams were taken without any misconduct, the prediction model would have the same explanatory power for all exams, and that if there was malpractice, the explanatory power would be lower. Their findings show that the two datasets are similar; there are variations in the independent variables that statistically and significantly predicted the Grade Point Average (GPA). The R-squared statistic suggests that the model for prediction is strong. Hence there is reason to believe that malpractice was taking place when the examinations were online, in spite of it being proctored. The goal of this paper is to provide teachers with practical ideas for administering proctored tests in their online courses.

A semi-synthetic natural product blocks collagen induced arthritis by preferentially suppressing the production of IL-6

Rheumatoid arthritis (RA), an autoimmune-inflammatory disease is characterized by dysregulation of signal transduction pathways, increased production of pro-inflammatory cytokines, enhanced leukocyte infiltration into synovial microvascular endothelium, extensive formation of hyper proliferative pannus, degradation of cartilage and bone erosion. Several compounds that abrogate cytokine production demonstrate a therapeutic effect in experimental models of arthritis. In this study, we report that a novel semi-synthetic natural product (Compound A) being a preferential IL-6 inhibitor, is efficacious in a murine model of arthritis. In vitro evaluations of pro-inflammatory cytokine production reveal that Compound A preferentially inhibits induced production of IL-6 and not TNF-α from THP-1 cells and isolated human monocytes. Furthermore, Compound A robustly inhibits the spontaneous production of IL-6 from pathologically relevant synovial tissue cells isolated from patients with active RA. In a physiologically relevant assay, Compound A selectively inhibits the activated T cell contact-mediated production of IL-6 from human monocytes. Compound A, at pharmacologically efficacious concentrations, does not significantly curtail the LPS-induced activation of p38 MAPKs. In the collagen-induced arthritis (CIA) mouse model (i) macroscopic observations demonstrate that Compound A, administered subcutaneously in a therapeutic regimen, significantly and dose-dependently inhibits disease associated increases in articular index and paw thickness; (ii) histological analyses of paw tissues reveal that Compound A prominently diminishes joint destruction, hyperproliferative pannus formation and infiltration of inflammatory cells. Collectively, these results provide direct evidence that Compound A, a novel preferential IL-6 inhibitor, suppresses collagen-induced arthritis, and may be a potential therapeutic for treating patients with active RA.

18F9 (4-(3,6-bis (ethoxycarbonyl)-4,5,6,7-tetrahydrothieno (2,3-c) pyridin-2-ylamino)-4-oxobutanoic acid) enhances insulin-mediated glucose uptake in vitro and exhibits antidiabetic activity in vivo in db/db mice

Insulin resistance is central to the pathogenesis of type 2 diabetes mellitus. Previous studies have demonstrated that compounds that cause adipogenesis and improve glucose uptake in 3T3-L1 cells are potential insulin sensitizers. Therefore, we evaluated one such compound, 18F9, for (1) adipogenesis in human subcutaneous preadipocyte (SQ) cells, (2) glucose uptake in human skeletal muscle myotubes and SQ cells, and (3) antidiabetic activity in db/db mice. We also investigated its effect on ex vivo glucose uptake in soleus muscle isolated from continuously treated db/db mice. Gene expression profiling in soleus muscle and epididymal fat of db/db mice was performed to understand its effect on glucose metabolism, lipid metabolism, and thermogenesis. 18F9 enhanced adipogenesis in SQ cells and increased glucose uptake in SQ and human skeletal muscle myotubes cells. In db/db mice, 18F9 exhibited dose-dependent reduction in plasma glucose and insulin level. Interestingly, 18F9 was as efficacious as rosiglitazone but did not cause body weight gain and hepatic adverse effects. In addition, 18F9 demonstrated no change in plasma volume in Wistar rats. Furthermore, it enhanced ex vivo glucose uptake in soleus muscles in these mice, which substantiates our in vitro findings. Human peroxisome proliferator activated receptor-gamma transactivation assay revealed a weak peroxisome proliferator activated receptor-gamma transactivation potential (44% of rosiglitazone at 10 mumol/L) of 18F9. Gene expression profiling indicated that 18F9 increased insulin sensitivity mainly through a phosphoinositide 3-kinase-dependent mechanism. 18F9 also up-regulated genes involved in lipid transport and synthesis at par with rosiglitazone. Unlike rosiglitazone, 18F9 elevated the expression of Pdk4. In addition, 18F9 elevated the expression of glycogen synthase and adiponectin significantly higher than rosiglitazone. Taken together, these observations suggest that 18F9 is a safer and potent insulin sensitizer that demonstrates promising antidiabetic activity and is worth further development.

Hydrolysis of nipecotic acid phenyl esters

The synthesis and anticonvulsant activity of nipecotic acid esters (1a-1f) have been previously reported. It was thought that these prodrug esters underwent hydrolytic conversion to 1 which inhibited GABA uptake, and that both 1 and an intact ester may have caused inhibition of GABA uptake which resulted in the anticonvulsant activity. There is, however, no stability data available to help evaluate these effects. We have determined degradation half-lives (t 1/2) of these phenyl esters dissolved in 10% serum solution or in pH 7.4 buffer (ionic strength = 0.25 adjusted with KCl) at 37 degrees C by monitoring the appearance of a phenolic compound for a period of 12 h with an HPLC method. Utilizing a published method, in vitro [14C]GABA uptake was measured. Results show that the hydrolysis rate in 10% serum solution was faster than that in buffer solution and that half-lives varied between 0.20 and 3.84 h. The uptake inhibition varied between 8.2 and 41.7% at 0.02 mM concentration, and percent GABA uptake inhibition correlated with log t 1/2 (r = -0.9827, p = 0.00045, based on a t test). Our data suggest that at concentrations ranging from 0.02 to 1 mM, inhibition of GABA uptake is mainly due to 1 formed after hydrolysis of 1a-1f.