Analysis of thermal-probe measurements using an iterative method to give sample conductivity and diffusivity data

The application of Microsoft Excel Solver routines to analyze data from a thermal probe placed in a number of samples is described. The successful application of the Solver routine to the thermal probe temperature time data requires the selection of an appropriate time interval. The various critical times are discussed and a method is proposed for selecting the appropriate Solver routine and the time interval over which the experimental data must be analyzed. Values of the sample thermal conductivity, the thermal diffusivity and the probe to sample conductance are reported for a stainless steel probe in unused mineral oil, and paraffin wax and for a copper probe in Magna904 and PTFE. The results for a commercial probe in agar agree with accepted data for water and the results for a clay-straw mixture demonstrates the method applied to a good insulator

Construction of BLDC motor with outer rotor

Tato prce je zamÄena na konstrukci EC motoru s vnÄj­m rotorem. Jej­m kolem je seznmen­ s konstrukc­, zkladn­mi vztahy, uplatnÄn­m tohoto typu motoru, s postupem nvrhu magnetick©ho obvodu s permanentn­mi magnety a nslednm nvrhem motoru. Dle pak dojde k ovÄen­ navrhnut©ho motoru metodou koneÄnch prvk. V neposledn­ adÄ shrne charakteristick© vlastnosti a veliÄiny nvrhu a dojde k porovnn­ prvotn­ho nvrhu s dal­mi dvÄma nvrhy s urÄitmi zmÄnami v oblasti zub statoru.This work is focused on the construction of the BLDC motor with outer rotor . Its mission is to become familiar with the design, basic relationships, applying this type of motor, the design procedure of magnetic circuit with permanent magnets, and then design the engine. Then there is a verification of designed motor finite element method. Finally, it summarizes the characteristics and parameters of the proposal and will compare the initial design with the other two designs, with some changes in the stator teeth.

Students’ Engagement in Independent Learning and Personal Development: Issues, Attitudes and Difficulties from the Female Learners’ Lived Experiences of Using Social Media in the Context of Saudi Higher Education

Personal access to digital information affects all situations in life, from lifelong learning and careers to teaching and learning practices. Recently, there has been interest in individuals’ uses of social media, its association with personal and academic development, and its extensive use in both formal and informal educational contexts. In the Kingdom of Saudi Arabia (KSA), particular research attention has been given to females’ use of social media due to the significance of such easy access to their learning and development in the broader cultural context. However, little is known about the educational implications of such extended personal learning practices. For instance, the issues, attitudes and difficulties of students’ engagement, and the students’ changing needs and expectations under current social media influence, are still not fully understood. This research employs an Interpretive Phenomenological Analysis (IPA) to investigate the lived learning experiences of female university students, focusing on their personal use of social media to examine current issues in students’ experiences in Saudi higher education. A group of female undergraduate learners in a Saudi higher education context were selected to offer the learners’ voice and perspective on educational issues related to their own engagement. Students’ personal accounts and different stories of engagement in independent learning and personal development from their use of social media have been collected through two phases. In the first phase, 20 female students participated in in-depth individual interviews and reflective diary reports. In the second phase, 12 female students participated in two focus group discussions to elicit their attitudes and opinions. The (IPA) analysis of the data drawing from different educational theories in the literature was used to understand factors related to students’ engagement and non-engagement from their different attitudes and stories of success and failure when using social media independently. Themes that emerged as drivers and motivations leading to students’ engagement in learning and personal development included self-efficacy and reflection, personal values and beliefs, awareness of opportunity, challenges and transitions, social inclusion and empowerment with learning choice. Several themes were also revealed from the personal accounts as barriers and difficulties for students’ engagement, including personal negative attitudes and experiences, understanding of social media risk, information overload and distraction, organisational, pedagogical and curriculum barriers, lack of social inclusion, technical problems, and time and cost issues. The research concludes with several recommendations for improving all students’ engagement under the current themes of personal and self-directed lifelong learning with matching curriculum and pedagogies adopted in this context to meet current student learning needs

Markdowns in Seasonal Conspicuous Goods

In common parlance, luxury and markdowns are, in many respects, contradictory concepts. Markdowns decrease product exclusivity and hence consumers’ willingness to pay (i.e., snob effect) since most consumers purchasing luxury desire uniqueness. Markdowns also encourage strategic (forward-looking) consumers to wait for lower prices (i.e., strategic effect). Yet, luxury retailers frequently adopt markdowns in practice to stimulate the demand for their seasonal products (i.e., sales effect). To study the impact of these three countervailing effects on a luxury retailer’s markdown policy and rationing strategy, this paper develops a game-theoretic model with strategic and exclusivity-seeking consumers who have heterogeneous (high and low) valuations. We characterize a luxury retailer’s equilibrium markdown and rationing strategies, and find that the retailer induces a buying frenzy (i.e., selling deliberately less than the demand) to increase consumers’ willingness to pay when they are sufficiently exclusivity-seeking. We show that the retailer’s markdown policy depends on consumers’ desire for exclusivity when the proportion of consumers with high valuation is not too high or too low. Interestingly, we find that, in such cases, consumers’ higher desire for exclusivity does not motivate the retailer to increase exclusivity and to adopt uniform pricing. To the contrary, it motivates the retailer to decrease the exclusivity and to adopt markdowns. By doing so, we identify exclusivity-seeking consumer behavior as another rationale behind markdown pricing. Lastly, we find that, when selling to exclusivity-seeking consumers, the negative impact of strategic consumer behavior is lower; however, ignoring it can be more costly

Clade identification of symbiotic zooxanthellae of dominant sclerectinian coral species of intertidal pools in Hengam Island

Zooxanthellae of reef-building corals are unicellular dinoflagellates of the Symbiodinium genus, which has an important role in bleaching phenomenon. Symbiodinium and their coral hosts are sensitive to environmental stresses that include salinity, high temperatures, low temperatures, extreme light levels and turbidity. Tidal pools have harsh conditions due to lack of nutrients, food and pronounced changes in physical conditions such as pH, salinity and temperature, hence the study of symbiotic zooxanthellae on coral reefs of tidal pool seems to be necessary. Samples of five coral species that include Siderastrea savignyana, Coscinaraea columna, Anomastrea irregulariis, Cyphastrea serailia, Psammocora superficialis were collected at intertidal pool of Hengam Island in the northern Persian Gulf. Partial 28S nuclear ribosomal (nr) DNA of Symbiodinium were amplified by polymerase chain reaction (PCR) and then PCR products were analyzed by the phylogenetic analyses of the LSU DNA sequences based on PAUP and Clustal X software. The results showed that there are at least two clades of Symbiodinium from Hengam Island. Clade D was detected from 3 of the coral species whileclade C was found in 2 species only. This study showed dominance of clade D at intertidal pool in Hengam Island and the dominace of clade D might be explained by the high environmental stresses for the Persian Gulf.Key words: Persian Gulf, clade D, tides, Symbiodinium and Hengam Island

Therapeutic safety and efficacy of triple-immunosuppressants versus dual-immunosuppressants in severe-to-critical COVID-19: a prospective cohort study in Bangladesh

Background: Hyperinflammation-induced respiratory failure is a leading cause of mortality in COVID-19 infection. Immunosuppressants such as, Baricitinib and interleukin inhibitors are the drug-of-choice to suppress cytokine storm in COVID-19. Here, we compared the therapeutic safety and efficacy of triple-immunosuppressants with dual-immunosuppressants in patients with severe-to-critical COVID-19. Methods: This study was conducted on 103 confirmed COVID-19 patients. Of 103 patients, 49 (N) and 54 (N) patients received dual-immunosuppressants (baricitinib plus two doses of secukinumab) and triple immunosuppressants (baricitinib plus single dose of tocilizumab and secukinumab) in group A and group B, respectively. Groups were compared in terms of clinical outcome, critical support-requirement, survival, re-hospitalisation, and adverse events (AEs). Results: Patients in group B achieved normal blood oxygen saturation level (SpO2) earlier than the patients of group A [4 day (IQR: 3–12) vs 5 day (IQR: 5–14), p .05]. The 60-day re-hospitalisation rate was two-fold high in group A than group B (p =.024). Immunosuppressant-associated adverse events and secondary bacterial/fungal infections were relative high in patients of group B. Conclusions: Triple-immunosuppressants in severe-to-critical COVID-19 infection exhibited better clinical outcome; reduced ICU and MV requirement; shorter hospital stay with deceased 60-day all cause mortality and re-hospitalisation compared to dual-immunosuppressants

AoA-Based Pilot Assignment in Massive MIMO Systems Using Deep Reinforcement Learning

In this paper, the problem of pilot contamination in a multi-cell massive multiple input multiple output (M-MIMO) system is addressed using deep reinforcement learning (DRL). To this end, a pilot assignment strategy is designed that adapts to the channel variations while maintaining a tolerable pilot contamination effect. Using the angle of arrival (AoA) information of the users, a cost function, portraying the reward, is presented, defining the pilot contamination effects in the system. Numerical results illustrate that the DRL-based scheme is able to track the changes in the environment, learn the near-optimal pilot assignment, and achieve a close performance to that of the optimum pilot assignment performed by exhaustive search, while maintaining a low computational complexity

Functional characterization of 8-oxoguanine DNA glycosylase of Trypanosoma cruzi

The oxidative lesion 8-oxoguanine (8-oxoG) is removed during base excision repair by the 8-oxoguanine DNA glycosylase 1 (Ogg1). This lesion can erroneously pair with adenine, and the excision of this damaged base by Ogg1 enables the insertion of a guanine and prevents DNA mutation. In this report, we identified and characterized Ogg1 from the protozoan parasite Trypanosoma cruzi (TcOgg1), the causative agent of Chagas disease. Like most living organisms, T. cruzi is susceptible to oxidative stress, hence DNA repair is essential for its survival and improvement of infection. We verified that the TcOGG1 gene encodes an 8-oxoG DNA glycosylase by complementing an Ogg1-defective Saccharomyces cerevisiae strain. Heterologous expression of TcOGG1 reestablished the mutation frequency of the yeast mutant ogg1-/- (CD138) to wild type levels. We also demonstrate that the overexpression of TcOGG1 increases T. cruzi sensitivity to hydrogen peroxide (H2O2). Analysis of DNA lesions using quantitative PCR suggests that the increased susceptibility to H2O2 of TcOGG1-overexpressor could be a consequence of uncoupled BER in abasic sites and/or strand breaks generated after TcOgg1 removes 8-oxoG, which are not rapidly repaired by the subsequent BER enzymes. This hypothesis is supported by the observation that TcOGG1-overexpressors have reduced levels of 8-oxoG both in the nucleus and in the parasite mitochondrion. The localization of TcOgg1 was examined in parasite transfected with a TcOgg1-GFP fusion, which confirmed that this enzyme is in both organelles. Taken together, our data indicate that T. cruzi has a functional Ogg1 ortholog that participates in nuclear and mitochondrial BER. © 2012 Furtado et al

Impact of high dose of baricitinib in severe COVID-19 pneumonia: a prospective cohort study in Bangladesh

Purpose: Hyperinflammation in severe COVID-19 infection increases the risk of respiratory failure and one of the cogent reasons of mortality associated with COVID-19. Baricitinib, a janus kinases inhibitor, can potentially suppress inflammatory cascades in severe COVID-19 pneumonia. Methods: The objective of this study was to compare the clinical outcomes of high dose of baricitinib with its usual dose in patients with severe COVID-19 pneumonia. This prospective cohort study was conducted on 238 adult patients with severe COVID-19 pneumonia. Eight milligram and 4 mg of baricitinib was given orally to 122 patients in the high dose (HD) group and 116 patients the usual dose (UD) group, respectively daily for 14 days, and clinical outcomes were compared among the groups. Results: Blood oxygen saturation level was stabilized (≥94% on room air) earlier in the HD group compared to the UD group [5 (IQR: 4–5)/8 (IQR: 6–9), P 0.05; N = 116/122, respectively]. The 30-day mortality and 60-day rehospitalization rate were higher in the UD group than the HD group [6%/3.3%, P 0.05; N = 116/122, respectively]. Conclusion: The daily high dose of baricitinib in severe COVID-19 results in early stabilization of the respiratory functions, declined requirements of critical care supports, reduced rehospitalization with mortality rate compared to its daily usual dose