226 research outputs found

    "It Puts us in our Students' Shoes": Listening to Voices from Teacher Candidates on Their Test-Taking Experience

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    This study explores teacher candidates' experiential learning through their test-taking experiences while attending a Bachelor of Education (B. Ed.) program. Eighty-four written reflections by teacher candidates taking a mid-term course examination on classroom assessment practices were analyzed. Major themes emerging from these reflections on the test-taking experience are related to validity concepts of construct representation, construct-irrelevant variance, relevance, and fairness. The study reveals that the test-taking experience could be valuable to teacher candidates in their learning of classroom assessment practices and in their understanding of the issues in test taking that may influence test performance. This, in turn, could potentially provide teacher candidates with a direct framework for their future classroom assessment practices, by which they may support their own future students

    CFD Analysis and Experiment Study of the Rotary Two-Stage Inverter Compressor with Vapor Injection

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    The offset angle of the upper and lower part of the crankshaft will affect the resistance of inspiration of high stage cylinder in the rotary two-stage inverter compressor with vapor injection, and then affect the performance. this paper presents the performance of the rotary two-stage inverter compressor with vapor injection in the bias angle of the crankshaft is calculated and compared with the experimental. The simulation results are in agreement with the experimental results. Under the operation of close vapor injection and open vapor injection, the performance of compressor can be improved 1% and 3% separately by optimize the bial angle of crankshaft.

    CCD photometric study of the W UMa-type binary II CMa in the field of Berkeley 33

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    The CCD photometric data of the EW-type binary, II CMa, which is a contact star in the field of the middle-aged open cluster Berkeley 33, are presented. The complete R light curve was obtained. In the present paper, using the five CCD epochs of light minimum (three of them are calculated from Mazur et al. (1993)'s data and two from our new data), the orbital period P was revised to 0.22919704 days. The complete R light curve was analyzed by using the 2003 version of W-D (Wilson-Devinney) program. It is found that this is a contact system with a mass ratio q=0.9q=0.9 and a contact factor f=4.1f=4.1%. The high mass ratio (q=0.9q=0.9) and the low contact factor (f=4.1f=4.1%) indicate that the system just evolved into the marginal contact stage

    Thiamine Deficiency Causes Long-Lasting Neurobehavioral Deficits in Mice

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    Thiamine deficiency (TD) has detrimental effects on brain health and neurobehavioral development, and it is associated with many aging-related neurological disorders. To facilitate TD-related neuropsychological studies, we generated a TD mouse model by feeding a thiamine-deficient diet for 30 days, followed by re-feeding the control diet for either one week or 16 weeks as recovery treatment. We then performed neurobehavioral tests in these two cohorts: cohort of one week post TD treatment (1 wk-PTDT) and 16 weeks post TD treatment (16 wks-PTDT). The TD mice showed no significant difference from control in any tests in the 1 wk-PTDT cohort at the age of 13–14 weeks. The tests for the 16 wks-PTDT cohort at the age of 28–29 weeks, however, demonstrated anxiety and reduced locomotion in TD animals in open field and elevated plus maze. In comparison, rotor rod and water maze revealed no differences between TD and control mice. The current findings of the differential effects of the same TD treatment on locomotion and anxiety at different ages may reflect the progressive and moderate change of TD-induced neurobehavioral effects. The study suggests that, even though the immediate neurobehavioral impact of TD is modest or negligible at a young age, the impact could develop and become severe during the aging process

    The Accountability of the Offshore Drilling Platform’s Oil Pollution Damages in the COPC Incident

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    *张丽英,中国政法大学国际法学院教授,副院长,博士生导师,中国海事仲裁委员会仲裁员,中国海商法协会常务理事。电子邮箱:[email protected]。 **刘佳,中国政法大学国际法学院研究生。电子邮箱:[email protected]。[文摘]渤海湾蓬莱19-3油田溢油事件引起了广泛关注,如何追究相关责任方的油污损害责任成为当务之急,但责任追究之路的重重困难使我国海上钻井平台油污损害责任追究相关法律和制度的不足日益凸显,包括责任主体不明、请求主体不全面、赔偿范围模糊不清、处罚力度过低等问题。反观美国墨西哥湾漏油事件,其处理的及时和赔偿的到位值得我们借鉴。本文在比较美国墨 西哥湾漏油事件及美国相关国内法的基础上,认为我国应在建立健全相关法律法规,明确具体地规定不同污染来源时的对应责任主体,扩大请求主体和赔偿范围,提高责任限额等方面进行改进。[Abstract]The Bohai Bay oil spill has brought to the fore certain issues concerning the assignment of liability to parties involved in offshore environmental damages.The incident has highlighted weaknesses in China’s current system of accountability in offshore oil drilling,namely ambiguous definition of responsible party,incomplete range of claimants,vague scope of compensation and lax administrative punishment.The U.S. Gulf of Mexico oil spill and its aftermath,by contrast,demonstrated elements of an effective legal response to a similar environmental incident,specifically with respect to liability and compensation,and can therefore serve as an instructive case study in efforts to advance the Chinese offshore drilling legal regime.After comparing the two aforementioned incidents and the respective legal lessons learned therein,the authors conclude that elucidating the process of identifying responsible parties,expanding the scope of compensation,and increasing liability limits are necessary actions for improving the efficacy and efficiency of relevant Chinese laws

    15-Deoxy-Δ 12,14

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    It has been reported that bone marrow-derived mesenchymal stem cells (BMSCs) have capacity to migrate to the damaged liver and contribute to fibrogenesis in chronic liver diseases. 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), an endogenous ligand for peroxisome proliferator-activated receptor gamma (PPARγ), is considered a new inhibitor of cell migration. However, the actions of 15d-PGJ2 on BMSC migration remain unknown. In this study, we investigated the effects of 15d-PGJ2 on the migration of BMSCs using a mouse model of chronic liver fibrosis and primary mouse BMSCs. Our results demonstrated that in vivo, 15d-PGJ2 administration inhibited the homing of BMSCs to injured liver by flow cytometric analysis and, in vitro, 15d-PGJ2 suppressed primary BMSC migration in a dose-dependent manner determined by Boyden chamber assay. Furthermore, the repressive effect of 15d-PGJ2 was blocked by reactive oxygen species (ROS) inhibitor, but not PPARγ antagonist, and action of 15d-PGJ2 was not reproduced by PPARγ synthetic ligands. In addition, 15d-PGJ2 triggered a significant ROS production and cytoskeletal remodeling in BMSCs. In conclusion, our results suggest that 15d-PGJ2 plays a crucial role in homing of BMSCs to the injured liver dependent on ROS production, independently of PPARγ, which may represent a new strategy in the treatment of liver fibrosis

    Epidemiology of atrial fibrillation and risk of CVD mortality among hypertensive population: A prospective cohort study in Northeast China

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    BackgroundDetermining risk factors of cardiovascular disease (CVD)-related mortality and evaluating their influence are important for effectively reducing corresponding mortality. However, few research findings have estimated the relationship between atrial fibrillation (AF) and CVD-related mortality among hypertension individuals.ObjectiveThe objective of this study was to investigate the epidemiology of AF in a hypertension population and determine the relationship between AF and CVD-related mortality.MethodsUsing a multistage, stratified, and cluster random sampling method, the prospective cohort study with a median follow-up of 3.51 years enrolled 10,678 hypertensive participants at baseline. The prevalence, awareness, and anticoagulation data of AF in this focal population were carefully assessed. Stepwise logistic regression and Cox regression analysis were respectively performed to evaluate the determinants of AF and the association between AF and CVD-related mortality.ResultsThe overall prevalence of AF was 1.3% (95% CI, 1.1%−1.6%) in the hypertensive population, and it was higher in men than in women (1.8% vs. 1.0%, respectively; p=0.001). The awareness of AF was 53.1%, and the rate of oral anticoagulant (OAC) therapy was only 4.2%, although all AF participants should have required according to the European Society of Cardiology guidelines. The determinants of AF included elder, male, and history of coronary heart disease in the hypertensive population. Besides, compared with individuals without AF, the risk of CVD-related mortality significantly increased in the hypertensive population with AF (HR 3.37, 95% CI 2.10–5.40).ConclusionOur results indicated a huge burden of AF and underuse of OAC therapy for them in a community-based hypertensive population. Considering that most of the risk factors of AF were unmodifiable in hypertensive individuals, as well as its high risk of mortality, long-term interventions including AF education, timely screening, and widespread use of OACs should be emphasized in the focal populations

    Service utilization in community health centers in China: a comparison analysis with local hospitals

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    BACKGROUND: Being an important part of China's Urban Health Care Reform System, Community Health Centers (CHCs) have been established throughout the entire country and are presently undergoing substantial reconstruction. However, the services being delivered by the CHCs are far from reaching their performance targets. In order to assess the role of the CHCs, we examined their performance in six cities located in regions of South-East China. The purpose of this investigation was to identify the utilization and the efficiency of community health resources that are able to provide basic medical and public health services. METHODS: The study was approved by Peking University Health Science Center Institutional Reviewing Board (NO: IRB00001052-T1). Data were collected from all the local health bureaux and processed using SPSS software. Methods of analysis mainly included: descriptive analysis, paired T-test and one-way ANOVA. RESULTS: The six main functions of the CHCs were not fully exploited and the surveys that were collected on their efficiency and utilization of resources indicate that they have a low level of performance and lack the trust of local communities. Furthermore, the CHCs seriously lack funding support and operate under difficult circumstances, and residents have less positive attitudes towards them. CONCLUSION: The community health service must be adjusted according to the requirements of urban medical and health reform, taking into account communities' health needs. More research is required on the living standards and health needs of residents living within the CHC's range, taking into consideration the users' needs in expanding the newly implemented service, and at the same time revising the old service system so as to make the development of CHCs realistic and capable of providing a better service to patients. Several suggestions are put forward for an attainable scheme for developing a community health service

    Potential health benefits of lowering gas production and bifidogenic effect of the blends of polydextrose with inulin in a human gut model

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    Polydextrose is a nutrient supplement, which is widely applied in the food industry. The use of polydextrose in combination with prebiotics and probiotics has recently increased, whereas the fermentation properties of its blend have not yet been fully revealed. We evaluated the metabolic profile of polydextrose, inulin, and their blends by a batch in vitro fermentation of fifteen human fecal inocula. After 24 h of fermentation, polydextrose increased the production of gas, ammonia, and several short chain fatty acids, including propionate and butyrate, when compared to its blends, inulin, and fructo-oligosaccharides. Furthermore, polydextrose had the slowest degradation rate of all the carbohydrates tested, consistent with its partial fermentation in the distal colon. The 16S rRNA gene sequencing analysis of the gut microbiome exhibited significantly increased relative abundance of Clostridium_XVIII, Megamonas, Mitsuokella, and Erysipelotrichaceae_incertae_sedis in polydextrose compared to other carbohydrates. On the other hand, the blends of polydextrose and inulin (1:1 or 2:1) showed reduced gas production and similar bifidogenicity to inulin alone. The blends not only had similar alpha-diversity and PCoA to inulin but also had a similar abundance of beneficial bacteria, such as Faecalibacterium and Roseburia, suggesting potential health benefits. Also their low gas production was likely due to the abundance of Faecalibacterium and Anaerostipes, which were negatively correlated with gas production. Additionally, our in vitro fermentation model shows advantages in the large-scale assessment of fermentation performance
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