2,633 research outputs found

    Effects of phytoestrogen on sexual development

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    Phytoestrogen is an estrogenic compound that occurs naturally in plants. The most common sources of phytoestrogen are soybean products, which contain high levels of isoflavones. This compound, which has structural similarity with estrogen, can act as an estrogen receptor agonist or antagonist. Animal studies provide evidence of the significant effects of phytoestrogen on sexual development, including altered pubertal timing, impaired estrous cycling and ovarian function, and altered hypothalamus and pituitary functions. Although human studies examining the effects of phytoestrogen on sexual development are extremely limited, the results of some studies agree with those of the animal studies. In this paper, we review the possible mechanism of phytoestrogen action and the evidence showing the effects of phytoestrogen on sexual development in animal and human studies

    Consensus of Corporate E-Learning System Stakeholders Regarding the Satisfaction of End-Users

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    The purpose of this study is to call attention to the consensus of stakeholders of corporate e-Learning system regarding success. We identified the critical success factors (contents, technical features, management, and organizational support) as major components of corporate eLearning systems and questioned whether stakeholders’ consensus on the importance of these components facilitates the implementation of these components to achieve good quality or well. We also questioned whether the influence of these components on user satisfaction could be moderated by contextual factors. Based on empirical testing of 18 eLearning user companies, we verified that the consensus of stakeholders regarding the importance of content, technological features, and organizational support has a positive influence on the perceived quality of these factors in their e-Learning systems, which in turn is positively related to user satisfaction. The learning subjects and learning style did significantly moderate the influences of these perceived qualities on user satisfaction

    Empirical Validation of Objective Functions in Feature Selection Based on Acceleration Motion Segmentation Data

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    Recent change in evaluation criteria from accuracy alone to trade-off with time delay has inspired multivariate energy-based approaches in motion segmentation using acceleration. The essence of multivariate approaches lies in the construction of highly dimensional energy and requires feature subset selection in machine learning. Due to fast process, filter methods are preferred; however, their poorer estimate is of the main concerns. This paper aims at empirical validation of three objective functions for filter approaches, Fisher discriminant ratio, multiple correlation (MC), and mutual information (MI), through two subsequent experiments. With respect to 63 possible subsets out of 6 variables for acceleration motion segmentation, three functions in addition to a theoretical measure are compared with two wrappers, k-nearest neighbor and Bayes classifiers in general statistics and strongly relevant variable identification by social network analysis. Then four kinds of new proposed multivariate energy are compared with a conventional univariate approach in terms of accuracy and time delay. Finally it appears that MC and MI are acceptable enough to match the estimate of two wrappers, and multivariate approaches are justified with our analytic procedures

    Genotypic Characterization of Vibrio vulnificus Clinical Isolates in Korea

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    AbstractObjectivesVibrio vunificus is known to cause septicemia and severe wound infections in patients with chronic liver diseases or an immuno-compromised condition. We carried out the molecular characterization of V. vulnificus isolates from human Vibrio septicemia cases based on pulsed-field gel electrophoresis (PFGE) using NotI and SfiI.Methods and ResultsPFGE was used to characterize a total of 78 strains from clinical cases after NotI or SfiI digestion. The geographical distribution of PFGE patterns for the strains from the southern part of Korea, a high-risk region for Vibrio septicemia, indicated that the isolates from southeastern Korea showed a comparatively higher degree of homology than those from southwestern Korea.ConclusionsWe report the genetic distribution of V. vulnficus isolated from Vibrio septicemia cases during 2000–2004 in Korea. This method has potential use as a subspecies-typing tool for V. vulnificus strains isolated from distant geographic regions

    Matematiksel Problem Çözme Yeterliliğinin Bileşenleri ve Matematiksel Modellemeye İlişkin Öğretim Stratejilerinin Aracılık Etkileri

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    This study is aimed at investigating the relationships between the components of problem solving skills (four procedural components and modeling competence) and the impact of instructional strategies (collaborative learning and problem posing) on students’ mathematical modeling competence. A survey on students’ mathematical problem solving competence, that was comprised of 40 items, was administered to 1,224 students in Korea and their responses were analyzed quantitatively (exploratory factor analysis, confirmatory factor analysis, and path analysis). The results indicated that students’ competencies regarding procedural components of mathematical problem solving positively affected their mathematical modeling competence. Additionally, instructional strategies utilizing collaborative learning and problem posing mediated and synergized the effect in terms of procedural components of mathematical problem solving and mathematical modeling competence. The study also discusses its contributions to and implications for mathematics educators and teachers.Bu çalışmanın amacı problem çözme becerisinin bileşenleri (dört adet yöntemsel bileşen ve modelleme yeterliliği) arasındaki ilişkilerin ve öğretim stratejilerinin (işbirlikçi öğrenme ve problem kurma) öğrencilerin matematiksel modelleme yeterliliği üzerindeki etkisini araştırmaktır. Kore’de 1224 öğrencinin katılımıyla öğrencilerin matematiksel problem çözme yeterliliğine ilişkin 40 maddeden oluşan bir anket gerçekleştirilmiş olup ankete verilen yanıtlar nicel yöntemler kullanılarak analiz edilmiştir (açımlayıcı faktör analizi, doğrulayıcı faktör analizi ve yol analizi). Anket sonuçları, öğrencilerin matematiksel problem çözmenin yöntemsel bileşenlerine ilişkin yeterliliklerinin matematiksel modelleme yeterlilikleri üzerinde olumlu etkisi olduğunu ortaya koymuştur. Ayrıca işbirlikçi öğrenme ve problem kurma yöntemlerinin kullanıldığı öğretim stratejileri, matematiksel problem çözmenin yöntemsel bileşenleri ile matematiksel modelleme yeterliliği açısından bir etki meydana getirmiş olup bu anlamda sinerji yaratmıştır. Çalışmada aynı zamanda matematik eğitimcileri ve öğretmenlerine yönelik katkı ve öneriler de tartışılmıştır

    Endoplasmic Reticulum Stress and Insulin Biosynthesis: A Review

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    Insulin resistance and pancreatic beta cell dysfunction are major contributors to the pathogenesis of diabetes. Various conditions play a role in the pathogenesis of pancreatic beta cell dysfunction and are correlated with endoplasmic reticulum (ER) stress. Pancreatic beta cells are susceptible to ER stress. Many studies have shown that increased ER stress induces pancreatic beta cell dysfunction and diabetes mellitus using genetic models of ER stress and by various stimuli. There are many reports indicating that ER stress plays an important role in the impairment of insulin biosynthesis, suggesting that reduction of ER stress could be a therapeutic target for diabetes. In this paper, we reviewed the relationship between ER stress and diabetes and how ER stress controls insulin biosynthesis
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