73 research outputs found

    Negotiating differences in academic preparedness among transnational students in higher education

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    “Students these days don’t know anything,” commented a faculty member in a focus group. But is it that students don’t know anything, or that faculty members are unfamiliar with what students do know? This is no small issue, as the acceleration of internationalization in higher education and the broader processes of globalization have led to increased numbers of students with general education profiles that differ from those of the instructors and their domestic students. These transnational students—not only international students (paying international tuition), but also permanent residents and citizens —received their primary and secondary (and, possibly, undergraduate) educations outside of Canada, and instructors often lack an awareness of their educational backgrounds and experiences. Emerging from a study of the everyday instructional needs of full-time college and university faculty, this paper presents the results of a systematic review of the literature on the general education of students from four regions that are sources of international students and immigrants, and, therefore, prepared students on campus: China, India, the Middle East, and Latin America. The research not only identifies the curriculum that these students followed, but also the impact of educational reforms on the teaching styles and learning skills emphasized in these systems, and describes the implications for Canadian instructors

    Experimental characterization of clay soils behavior stabilized by polymers

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    In this work, we propose to use both PVC and HDPE polymers such additions in cohesive soils to determine their influence on the physical and mechanical properties of soil-polymer material in function of time, which should insure some optimal period of life. For this purpose, different tests including Atterberg Limits, standard compaction, swelling potential, and swelling pressure, were conducted on control and treated soil samples using different Percentage of Polymer (PVC and HDPE) (0, 3 and 6%). Also California Bearing Ratio (CBR) tests were conducted on control and treated samples. The results showed that soil treatment with PVC and HDPE, resulted in improvement of CBR and maximum dry density and reduction in Atterberg Limits, swelling potential and swelling pressure. The addition of a small percentage of polymer causes initially at (t =0 sec) an instantaneous of deformation (elastic response), followed by a time-dependent deformation with the speed of the increasing deformation.Keywords: Mechanic; Polymer; Expansive clay; Optimum; Compressibilit

    Simultaneous optimal integration of photovoltaic distributed generation and battery energy storage system in active distribution network using chaotic grey wolf optimization

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    Goal. The integration of photovoltaic distributed generations in the active distribution network has raised quickly due to their importance in delivering clean energy, hence, participating in solving various problems as climate change and pollution. Adding the battery energy storage systems would be considered as one of the best choices in giving solutions to the mentioned issues due to its characteristics of quick charging and discharging, managing the quality of power, and fulfilling the peak of energy demand. The novelty of the proposed work is the development of new multi-objective functions based on the sum of the three technical parameters of total active power loss, total voltage deviation, and total operation time of the overcurrent protection relay. Purpose. This paper is dedicated for solving the allocation problem of hybrid photovoltaic distributed generation and battery energy storage systems integration in the standard IEEE 33-bus and IEEE 69-bus active distribution networks. Methodology. The optimal integration of the hybrid systems is formulated as minimizing the proposed multi-objective functions by applying a newly developed metaheuristic technique based on various chaotic grey wolf optimization algorithms. The applied optimization algorithms are becoming increasingly popular due to their simplicity, lack of gradient information needed, ability to bypass local optima, and versatility in power system applications. Results. The simulation results of both test systems confirm the robustness and efficiency of the chaotic logistic grey wolf optimization algorithm compared to the rest of the algorithms in terms of convergence to the global optimal solution and in terms of providing the best and minimum multi-objective functions-based power losses, voltage deviation and relay operation time values. Practical significance. Recommendations have been developed for the use of optimal allocation of hybrid systems for practical industrial distribution power systems with the renewable energy sources presence.Мета. Інтеграція фотоелектричної розподіленої генерації в активну розподільчу мережу швидко зросла завдяки її важливості для доставки чистої енергії, отже, участі у вирішенні різних проблем, таких як зміна клімату та забруднення. Додавання акумуляторних систем накопичення енергії може бути розглянуто як один з найкращих варіантів вирішення зазначених питань завдяки своїм характеристикам швидкої зарядки та розрядки, управління якістю енергії та задоволення піку енергетичних потреб. Новизна запропонованої роботи полягає у розробці нових багатоцільових функцій на основі суми трьох технічних параметрів сумарних втрат активної потужності, загальних відхилень напруги та загального часу спрацьовування реле захисту від перевантаження по струму. Мета. Стаття присвячена вирішенню проблеми розподілу гібридних фотоелектричних розподілених систем генерації та інтеграції систем накопичення енергії в стандартні активні розподільчі мережі з 33-шинами IEEE та 69-шинами IEEE. Методологія. Оптимальна інтеграція гібридних систем сформульована як мінімізація запропонованих багатоцільових функцій шляхом застосування нещодавно розробленої метаевристичної методики, заснованої на різних хаотичних алгоритмах оптимізації сірого вовка. Застосовані алгоритми оптимізації стають дедалі популярнішими завдяки своїй простоті, відсутності необхідної інформації щодо градієнту, можливості обходу локальних оптимумів та універсальності в застосуваннях щодо енергосистеми. Результати. Результати моделювання обох тестових систем підтверджують надійність та ефективність хаотичного логістичного алгоритму оптимізації сірого вовка в порівнянні з іншими алгоритмами з точки зору збіжності до глобального оптимального розв‘язання та з точки зору забезпечення найкращих і мінімальних багатоцільових функцій на основі втрат потужності, відхилення напруги та значень часу спрацювання реле. Практичне значення. Розроблено рекомендації щодо використання оптимального розподілу гібридних систем для реальних промислових розподільчих енергосистем із наявністю відновлюваних джерел енергії

    Inhibitory Activity of Leaves Extracts of Citrullus colocynthis Schrad. on HT29 Human Colon Cancer Cells

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    Aims: Citrullus colocynthis is a plant endemic in Asia, Africa and in the Mediterranean basin. It is used in folk medicine against infections, inflammations and cardiovascular and immune-related diseases. There are further evidences of the use of Citrullus colocynthis Schrad in the treatment of cancer in traditional practices. The present study aimed to determine the potential antiproliferative effects of different Citrullus colocynthis leaf extracts on human cancer cells. Methodology: Antiproliferative and antioxidant effects on HT-29 human colon cancer cells were detected by MTS assay and a modified protocol of the alkaline Comet assay. In vitro antioxidant activities of different leaf extracts were evaluated through DPPH, \u3b2-carotene/linoleic acid and reducing power assays. Results: The leaf chloroform extract exhibited the higher cell growth inhibitory activity without induction of DNA damage; it showed to be able to significantly decrease DNA damage induced by H2O2 (100 M). This antioxidant activity seems to be comparable to that of vitamin C (1 mM). Ethyl acetate, acetone and methanol leaf extracts showed to be the most effective in reducing the stable free DPPH radical (IC50 =113 g/ml), in transforming the Fe3+ to Fe2+ (IC50 = 134 \ub5g/ml) and in inducing linoleic acid oxidation with an inhibition of 31.9 %. Conclusion: Our results confirm the antiproliferative potential of Citrullus colocynthis Schrad. on human cancer cells

    Conservative route to genome compaction in a miniature annelid

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    The causes and consequences of genome reduction in animals are unclear because our understanding of this process mostly relies on lineages with often exceptionally high rates of evolution. Here, we decode the compact 73.8-megabase genome of Dimorphilus gyrociliatus, a meiobenthic segmented worm. The D. gyrociliatus genome retains traits classically associated with larger and slower-evolving genomes, such as an ordered, intact Hox cluster, a generally conserved developmental toolkit and traces of ancestral bilaterian linkage. Unlike some other animals with small genomes, the analysis of the D. gyrociliatus epigenome revealed canonical features of genome regulation, excluding the presence of operons and trans-splicing. Instead, the gene-dense D. gyrociliatus genome presents a divergent Myc pathway, a key physiological regulator of growth, proliferation and genome stability in animals. Altogether, our results uncover a conservative route to genome compaction in annelids, reminiscent of that observed in the vertebrate Takifugu rubripes

    In vivo and in silico studies of the effects of oil extracted from Cannabis sativa L. seeds on healing of burned skin wounds in rats

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    IntroductionThis study investigates the potential effects of cannabis seed oil (CSO) on the wound healing process. The aim was to assess the efficacy of CSO in treating skin wounds using an animal model and to explore its anti-inflammatory properties through in silico analysis.MethodsEighteen male albino Wistar rats, weighing between 200 and 250 g, were divided into three groups: an untreated negative control group, a group treated with the reference drug silver sulfadiazine (SSD) (0.01 g/mL), and a group treated topically with CSO (0.962 g/mL). The initial wound diameter for all groups was 1 cm. In silico studies were conducted using Maestro 11.5 to evaluate the anti-inflammatory effects of phytoconstituents against cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2).ResultsCSO and SSD treatments led to a significant reduction (p <0.05) in the size of burned skin wounds by day 5, with contraction rates of 53.95% and 45.94%, respectively, compared to the untreated negative control group. By day 15, wounds treated with CSO and SSD had nearly healed, showing contraction rates of 98.8% and 98.15%, respectively. By day 20, the wounds treated with CSO had fully healed (100%), while those treated with SSD had almost completely healed, with a contraction rate of 98.97%. Histological examination revealed granulated tissue, neo-blood vessels, fibroblasts, and collagen fibers in wounds treated with CSO. In silico studies identified arachidic acid, γ-linolenic acid, and linolenic acid as potent inhibitors of COX-1 and COX-2. Serum biochemical parameters indicated no significant changes (p > 0.05) in liver and kidney function in rats treated with CSO, whereas a significant increase (p < 0.01) in ALAT level was observed in rats treated with SSD.DiscussionThe findings demonstrate that CSO has a promising effect on wound healing. The CSO treatment resulted in significant wound contraction and histological improvements, with no adverse effects on liver and kidney function.However, the study's limitations, including the small sample size and the need for detailed elucidation of CSO's mechanism of action, suggest that further research is necessary. Future studies should focus on exploring the molecular pathways and signaling processes involved in CSO’s pharmacological effects

    An overview of burst, buckling, durability and corrosion analysis of lightweight FRP composite pipes and their applicability

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    © 2019 Elsevier Ltd. All rights reserved.The main aim of this review article was to address the performance of filament wound fibre reinforced polymer (FRP) composite pipes and their critical properties, such as burst, buckling, durability and corrosion. The importance of process parameters concerning merits and demerits of the manufacturing methods was discussed for the better-quality performance. Burst analysis revealed that the winding angle of ±55° was observed to be optimum with minimum failure mechanisms, such as matrix cracking, whitening, leakage and fracture. The reduction of buckling effect was reported in case of lower hoop stress value in the hoop to axial stress ratio against axial, compression and torsion. A significant improvement in energy absorption was observed in the hybrid composite pipes with the effect of thermal treatment. However, the varying winding angle in FRP pipe fabrication was reported as an influencing factor affecting all the aforementioned properties. Almost 90% of the reviewed studies was done using E-glass/epoxy materials for the composite pipe production. By overcoming associated limitations, such as replacing synthetic materials, designing new material combinations and cost-benefit analysis, the production cost of the lightweight FRP composite pipes can be decreased for the real-time applications.Peer reviewe

    Effect of alirocumab on mortality after acute coronary syndromes. An analysis of the ODYSSEY OUTCOMES randomized clinical trial

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    Background: Previous trials of PCSK9 (proprotein convertase subtilisin-kexin type 9) inhibitors demonstrated reductions in major adverse cardiovascular events, but not death. We assessed the effects of alirocumab on death after index acute coronary syndrome. Methods: ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) was a double-blind, randomized comparison of alirocumab or placebo in 18 924 patients who had an ACS 1 to 12 months previously and elevated atherogenic lipoproteins despite intensive statin therapy. Alirocumab dose was blindly titrated to target achieved low-density lipoprotein cholesterol (LDL-C) between 25 and 50 mg/dL. We examined the effects of treatment on all-cause death and its components, cardiovascular and noncardiovascular death, with log-rank testing. Joint semiparametric models tested associations between nonfatal cardiovascular events and cardiovascular or noncardiovascular death. Results: Median follow-up was 2.8 years. Death occurred in 334 (3.5%) and 392 (4.1%) patients, respectively, in the alirocumab and placebo groups (hazard ratio [HR], 0.85; 95% CI, 0.73 to 0.98; P=0.03, nominal P value). This resulted from nonsignificantly fewer cardiovascular (240 [2.5%] vs 271 [2.9%]; HR, 0.88; 95% CI, 0.74 to 1.05; P=0.15) and noncardiovascular (94 [1.0%] vs 121 [1.3%]; HR, 0.77; 95% CI, 0.59 to 1.01; P=0.06) deaths with alirocumab. In a prespecified analysis of 8242 patients eligible for ≥3 years follow-up, alirocumab reduced death (HR, 0.78; 95% CI, 0.65 to 0.94; P=0.01). Patients with nonfatal cardiovascular events were at increased risk for cardiovascular and noncardiovascular deaths (P<0.0001 for the associations). Alirocumab reduced total nonfatal cardiovascular events (P<0.001) and thereby may have attenuated the number of cardiovascular and noncardiovascular deaths. A post hoc analysis found that, compared to patients with lower LDL-C, patients with baseline LDL-C ≥100 mg/dL (2.59 mmol/L) had a greater absolute risk of death and a larger mortality benefit from alirocumab (HR, 0.71; 95% CI, 0.56 to 0.90; Pinteraction=0.007). In the alirocumab group, all-cause death declined wit h achieved LDL-C at 4 months of treatment, to a level of approximately 30 mg/dL (adjusted P=0.017 for linear trend). Conclusions: Alirocumab added to intensive statin therapy has the potential to reduce death after acute coronary syndrome, particularly if treatment is maintained for ≥3 years, if baseline LDL-C is ≥100 mg/dL, or if achieved LDL-C is low. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01663402

    Challenges in Masters level education: Supervision, stress and mental health

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    Background and objective: In recent years, research has highlighted the prevalence of mental and emotional distress among graduate students. The objective of this manuscript-based PhD dissertation is to validate and iterate a conceptual model of Masters students mental health and wellbeing, with a focus on student expectations and the role of research supervision. Studies and findings: Manuscript #1, an integrative literature review, suggests a framework of four systems of graduate education that impact students’ emotional experiences: the culture and expectations of academia, the university and department, the lab and cohort systems, and the socio-economic system. Based on this framework, Manuscript #1 proposes a conceptual model for student experiences of mental and emotional distress and wellbeing that frames the research questions of the next studies. Manuscript #2 is a quantitative analysis focused on student expectations of graduate study. The results show that students whose expectations are aligned with their lived experiences of Masters study have less mental and emotional distress and greater wellbeing compared to students whose expectations do not match their lived experiences, and are less likely to consider withdrawing from their programs. Manuscript #3 is a qualitative analysis of Masters students’ descriptions of their graduate school expectations and experiences. Several themes are identified in the overall sample, including the importance of research and coursework, relationships, and academic culture. Students with aligned expectations in general reported more positive experiences of graduate school across all themes. The results also suggest an extension of the conceptual model presented in Manuscript #1, to include the idea that students perform a multi-factor cost-benefit analysis of their decision to enrol in their programs. Manuscript #4 is a mixed quantitative-qualitative study. Quantitative results show that students with greater satisfaction with supervision experience less mental and emotional distress and greater wellbeing compared to students who are dissatisfied. Qualitative results illustrate that satisfied students have positive experiences across different dimensions of supervision, whereas students who are not satisfied have equivocal or negative experiences across these dimensions. Discussion and conclusions: The dissertation findings support and extend the initial conceptual model. Several practical implications and recommendations are discussed
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