Motivational Social Visualizations for Personalized E-Learning

A large number of educational resources is now available on the Web to support both regular classroom learning and online learning. However, the abundance of available content produces at least two problems: how to help students find the most appropriate resources, and how to engage them into using these resources and benefiting from them. Personalized and social learning have been suggested as potential methods for addressing these problems. Our work presented in this paper attempts to combine the ideas of personalized and social learning. We introduce Progressor + , an innovative Web-based interface that helps students find the most relevant resources in a large collection of self-assessment questions and programming examples. We also present the results of a classroom study of the Progressor +  in an undergraduate class. The data revealed the motivational impact of the personalized social guidance provided by the system in the target context. The interface encouraged students to explore more educational resources and motivated them to do some work ahead of the course schedule. The increase in diversity of explored content resulted in improving students’ problem solving success. A deeper analysis of the social guidance mechanism revealed that it is based on the leading behavior of the strong students, who discovered the most relevant resources and created trails for weaker students to follow. The study results also demonstrate that students were more engaged with the system: they spent more time in working with self-assessment questions and annotated examples, attempted more questions, and achieved higher success rates in answering them

Direct measurements of the effects of salt and surfactant on interaction forces between colloidal particles at water-oil interfaces

The forces between colloidal particles at a decane-water interface, in the presence of low concentrations of a monovalent salt (NaCl) and of the surfactant sodium dodecylsulfate (SDS) in the aqueous subphase, have been studied using laser tweezers. In the absence of electrolyte and surfactant, particle interactions exhibit a long-range repulsion, yet the variation of the interaction for different particle pairs is found to be considerable. Averaging over several particle pairs was hence found to be necessary to obtain reliable assessment of the effects of salt and surfactant. It has previously been suggested that the repulsion is consistent with electrostatic interactions between a small number of dissociated charges in the oil phase, leading to a decay with distance to the power -4 and an absence of any effect of electrolyte concentration. However, the present work demonstrates that increasing the electrolyte concentration does yield, on average, a reduction of the magnitude of the interaction force with electrolyte concentration. This implies that charges on the water side also contribute significantly to the electrostatic interactions. An increase in the concentration of SDS leads to a similar decrease of the interaction force. Moreover the repulsion at fixed SDS concentrations decreases over longer times. Finally, measurements of three-body interactions provide insight into the anisotropic nature of the interactions. The unique time-dependent and anisotropic interactions between particles at the oil-water interface allow tailoring of the aggregation kinetics and structure of the suspension structure.Comment: Submitted to Langmui

Application of chitosan functionalized with 3,4-dihydroxy benzoic acid moiety for on-line preconcentration and determination of trace elements in water samples

Chitosan resin functionalized with 3,4-dihydroxy benzoic acid (CCTS-DHBA resin) was used as a packing material for flow injection (FI) on-line mini-column preconcentration in combination with inductively coupled plasma-atomic emission spectrometry (ICP-AES) for the determination of trace elements such as silver, bismuth, copper, gallium, indium, molybdenum, nickel, uranium, and vanadium in environmental waters. A 5-mL aliquot of sample (pH 5.5) was introduced to the minicolumn for the adsorption/preconcentration of the metal ions, and the collected analytes on the mini-column were eluted with 2 M HNO3, and the eluates was subsequently transported via direct injection to the nebulizer of ICP-AES for quantification. The parameters affecting on the sensitivity, such as sample pH, sample flow rate, eluent concentration, and eluent flow rate, were carefully examined. Alkali and alkaline earth metal ions commonly existing in river water and seawater did not affect the analysis of metals. Under the optimum conditions, the method allowed the determination of metal ions with detection limits of 0.08 ng mL(-1) (Ag), 0.9 ng mL(-1) (Bi), 0.07 ng mL(-1) (Cu), 0.9 ng mL(-1) (Ga), 0.9 ng mL(-1) (In), 0.08 ng mL(-1) (Mo), 0.09 ng mL(-1) (Ni), 0.9 ng mL(-1) (U), and 0.08 ng mL(-1) (V). By using 5 mL of sample solution, the enrichment factor and collection efficiency were 8-12 fold and 96-102%, respectively, whereas the sample throughput was 7 samples/hour. The method was validated by determining metal ions in certified reference material of river water (SLRS-4) and nearshore seawater (CASS-4), and its applicability was further demonstrated to river water and seawater samples.</p

Диагностические возможности сочетанной детекции амидолитической активности хепсина и метилирования гена GSTP1 при раке и других заболеваниях предстательной железы

We have assessed the implication of analysis of amydolitic activity of hepsin, which is a trans-membrane serine protease of II type, in the detection of prostate cancer diagnosis. According to literature review over-expression of hepsin is characteristic for prostate cancer whereas prostatic cells do not express this protease in normal states and benign tumors of prostate. Our results have demonstrated the value of screening for hepsin activity in the diagnosis of prostatic pathologies which possibly is an adequate substitution for widely used test of prostate specific antigen determination.

Ustekinumab as Induction and Maintenance Therapy for Crohn’s Disease

BACKGROUND Ustekinumab, a monoclonal antibody to the p40 subunit of interleukin-12 and inter-leukin-23, was evaluated as an intravenous induction therapy in two populations with moderately to severely active Crohn’s disease. Ustekinumab was also evaluated as subcutaneous maintenance therapy. METHODS We randomly assigned patients to receive a single intravenous dose of ustekinumab (either 130 mg or approximately 6 mg per kilogram of body weight) or placebo in two induction trials. The UNITI-1 trial included 741 patients who met the criteria for primary or secondary nonresponse to tumor necrosis factor (TNF) antagonists or had unacceptable side effects. The UNITI-2 trial included 628 patients in whom conventional therapy failed or unacceptable side effects occurred. Patients who completed these induction trials then participated in IM-UNITI, in which the 397 patients who had a response to ustekinumab were randomly assigned to receive subcutaneous maintenance injections of 90 mg of ustekinumab (either every 8 weeks or every 12 weeks) or placebo. The primary end point for the induction trials was a clinical response at week 6 (defined as a decrease from baseline in the Crohn’s Disease Activity Index [CDAI] score of ≥100 points or a CDAI score <150). The primary end point for the maintenance trial was remission at week 44 (CDAI score <150). RESULTS The rates of response at week 6 among patients receiving intravenous ustekinumab at a dose of either 130 mg or approximately 6 mg per kilogram were significantly higher than the rates among patients receiving placebo (in UNITI-1, 34.3%, 33.7%, and 21.5%, respectively, with P≤0.003 for both comparisons with placebo; in UNITI-2, 51.7%, 55.5%, and 28.7%, respectively, with P<0.001 for both doses). In the groups receiving maintenance doses of ustekinumab every 8 weeks or every 12 weeks, 53.1% and 48.8%, respectively, were in remission at week 44, as compared with 35.9% of those receiving placebo (P = 0.005 and P = 0.04, respectively). Within each trial, adverse-event rates were similar among treatment groups. CONCLUSIONS Among patients with moderately to severely active Crohn’s disease, those receiving intravenous ustekinumab had a significantly higher rate of response than did those receiving placebo. Subcutaneous ustekinumab maintained remission in patients who had a clinical response to induction therapy. (Funded by Janssen Research and Development; ClinicalTrials.gov numbers, NCT01369329, NCT01369342, and NCT01369355.

Is diet partly responsible for differences in COVID-19 death rates between and within countries?

Correction: Volume: 10 Issue: 1 Article Number: 44 DOI: 10.1186/s13601-020-00351-w Published: OCT 26 2020Reported COVID-19 deaths in Germany are relatively low as compared to many European countries. Among the several explanations proposed, an early and large testing of the population was put forward. Most current debates on COVID-19 focus on the differences among countries, but little attention has been given to regional differences and diet. The low-death rate European countries (e.g. Austria, Baltic States, Czech Republic, Finland, Norway, Poland, Slovakia) have used different quarantine and/or confinement times and methods and none have performed as many early tests as Germany. Among other factors that may be significant are the dietary habits. It seems that some foods largely used in these countries may reduce angiotensin-converting enzyme activity or are anti-oxidants. Among the many possible areas of research, it might be important to understand diet and angiotensin-converting enzyme-2 (ACE2) levels in populations with different COVID-19 death rates since dietary interventions may be of great benefit.Peer reviewe