Patterns in student-student commenting

The virtual classroom under consideration supports students submitting exercise answers online and comments on exercise answers that include numerical scores. Automated quality control procedures track the student scores. The patterns of scores vary as a function of the pragmatic import of these student scores. Clear consequences of commenting must be enforced in the classroom before students will engage in fruitful commenting. The managerial problems that arise in courses that rely on extensive student-student commenting can be partially solved with automated tools that guide students to comment in fair and flexible ways.     

The serotonin uptake-enhancing drug tianeptine suppresses asthmatic symptoms in children: a double-blind, crossover, placebo-controlled study

Studies have shown that levels of free serotonin in plasma are increased in symptomatic patients with asthma. In addition, the concentration of free serotonin in symptomatic patients with asthma correlates positively with clinical status and negatively with pulmonary function. Thus, reducing the concentration of free serotonin in plasma might be useful in treating patients with asthma. We studied the effectiveness of tianeptine in treating patients with asthma. Tianeptine is the only drug known to be able to reduce levels of free serotonin in plasma and to enhance uptake by platelets. In this study, 69 children with asthma were assigned in randomized fashion to receive tianeptine and/or placebo in a double-blind crossover trial that lasted 52 weeks. Tianeptine provoked a dramatic and sudden decrease in both clinical rating and free serotonin plasma levels and an increase in pulmonary function.     

Systems for reusing hypermedia courseware

Three systems of differing complexity have been built which support the development of courseware libraries for reuse at three differing organizations. One system was developed for a handful of authors at a small company, one for a university team of about twenty-five people, and one for a company with about one hundred authors. The small company has not found the cost-benefit balances attractive enough to continue investment. The university team has published several products with its collaborative hypermedia system. The system for the large company includes extremely sophisticated library structures and coordination mechanisms but is a challenge for the new user to fully understand. As is often the case with reuse, the institutional commitment to courseware reuse and the ease of use of the tools are critical factors in success. Based on the experiences with the first three courseware reuse systems and the increased popularity of the World Wide Web, a new courseware reuse methodology has been implemented on the World Wide Web.     

The local structure of gadolinium vanado-tellurite glasses

In this work we report on a vibrational spectroscopic, X-ray diffraction, and density measurement study of the structural properties of the ternary xGd₂O₃(100 − x)[7TeO₂·3V₂O₅] systems for various x values up to 70 mol%. Structural changes, as recognized by analyzing band shapes of X-ray diffraction and IR spectra, revealed that Gd₂O₃ causes a higher extent of network polymerization as far as x ≤ 40 mol%, while for x between 40 and 50 mol% showed a drastic structural modification which lead to the apparition of the GdVO₄ crystalline phase.     

Microwave-Assisted,Base-Catalyzed Synthesis of Fatty Acid Methyl Esters from Seeds and Fish Oil Supplements

Growing health awareness has resulted in the increased use of dietary supplements derived from plants and marine sources, leaving consumers unsure of their best options. There were three objectives of the present study. The first was to design and evaluate an efficient derivatization procedure. The second was to perform a comparative analysis of liquid oils and their corresponding capsules of hemp, chia, and flax seeds. The final objective was to determine the fatty acid (FA) composition of six fish oil products and compare it to the one provided on the label. For the FA profiling, we implemented two efficient, one-step, sustainable methods with high percentage recovery for the synthesis of FA methyl esters (FAME), which use base catalysis and microwave-assisted heating. Our results found no difference in nutritional value between liquid oils and capsules of the seed supplements, with flaxseed and chia offering a higher, beneficial n-3:n-6 ratio compared to hemp oil. Four of the fish oils analyzed contained significantly less eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) than their reported label, and the other two not only agreed with the manufacturers' declaration but were able to fulfill the daily adequate intake (AI) with fewer capsules.