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101.

Information and Announcements

Science Academies Refresher Course in condensed matter and statistical physics February 28–March 13, 2011  相似文献   
102.
The purpose of this study was to investigate the effects of the Common Knowledge Construction Model (CKCM) lesson sequence, an intervention based both in conceptual change theory and in Phenomenography, a subset of conceptual change theory. A mixed approach was used to investigate whether this model had a significant effect on 7th grade students' science achievement and conceptual change. The Excretion Unit Achievement Test (EUAT) indicated that students (N = 33) in the experimental group achieved significantly higher scores (p < 0.001) than students in the control group (N = 35) taught by traditional teaching methods. Qualitative analysis of students' pre‐ and post‐teaching conceptions of excretion revealed (1) the addition and deletion of ideas from pre‐ to post‐teaching; (2) the change in the number of students within categories of ideas; (3) the replacement of everyday language with scientific labels; and (4) the difference in the complexity of students' responses from pre‐ to post‐teaching. These findings contribute to the literature on teaching that incorporates students' conceptions and conceptual change. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47: 25–46, 2010  相似文献   
103.
Abnormal glomerular permeability is the primary step towards the glomerulosclerosis. The progression rate of glomerulosclerosis is proportionate to abundance and severity of lesions created at incipient stage, which is reflected as proteinuria even though eGFR remains in the normal range. Therefore, there is a current need to find out the association between relative risks for the factors leading to proteinuria. The relations could be more informative, if it is with respect to the macromolecules like “IgG” excretion in urine. Type 2 diabetic patients were selected for this study with eGFR > 75 ml/min/1.73 m2 and grouped into four quartiles based on UIgGCR. The markers of key factors affecting progression of proteinuria were estimated through biochemical tests. The impact of these markers on proteinuria was accessed by applying multinomial logistic regression. The adjusted odds ratio for the UGAGCR was 1.186 (95 % CI: 1.061–1.327) P < 0.003 in highest quartiles of UIgGCR, followed by odds ratio for markers of collagen catabolism 1.051 (95 % CI: 1.025–1.079) P < 0.001, and USACR 1.044 (95 % CI: 1.013–1.077) P < 0.006 respectively. The marker of glycation, i.e., glycated hemoglobin showed the highest odds ratio 5.449 (95 % CI: 1.132–26.236) P < 0.035. In addition, odds for the systolic blood pressure was observed 1.387 (95 % CI: 1.124–1.712) P < 0.002. The higher odds inform and could help to discriminate the diabetic patients with fast progressive diabetic nephropathy. The study describes critical relationship between the urinary excretion of IgG and factors leading to proteinuria in type 2 diabetic patients.  相似文献   
104.
Chlorella vulgaris (CV) has been reported to have antioxidant and anticancer properties. We evaluated the effect of CV on apoptotic regulator protein expression in liver cancer-induced rats. Male Wistar rats (200-250 g) were divided into eight groups: control group (normal diet), CDE group (choline deficient diet supplemented with ethionine in drinking water to induce hepatocarcinogenesis), CV groups with three different doses of CV (50, 150, and 300 mg/kg body weight), and CDE groups treated with different doses of CV (50, 150, and 300 mg/kg body weight). Rats were sacrificed at various weeks and liver tissues were embedded in paraffin blocks for immunohistochemistry studies. CV, at increasing doses, decreased the expression of anti-apoptotic protein, Bcl-2, but increased the expression of pro-apoptotic protein, caspase 8, in CDE rats, which was correlated with decreased hepatoctyes proliferation and increased apoptosis as determined by bromodeoxy-uridine (BrdU) labeling and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, respectively. Our study shows that CV has definite chemopreventive effect by inducing apoptosis via decreasing the expression of Bcl-2 and increasing the expression of caspase 8 in hepatocarcinogenesis-induced rats.  相似文献   
105.
Equitable computer collaborations in mixed-gender teams have been a pressing issue for many years. While some have argued for creating single-gender teams or girls-only computer activities, our approach was different. The current study examines a three-month software design activity in which mixed teams of girls and boys (10–12 year olds) designed and implemented multimedia astronomy resources for younger students. In this context we assessed gender differences in students' levels of access to technology and how these participation patterns changed throughout the project duration. We found through our qualitative analyses that the configuration of social, physical and cognitive spaces in the project environment contributed to a positive change in girls' levels of access. We discuss the implications of these results in regard to issues surrounding the development and maintenance of gender equity in computer use and further research.  相似文献   
106.
107.
Activities of antioxidant enzymes involved oxygen free radical metabolism in the liver and lung were investigated in 2,4, and 30 months old Wistar albino rats. The levels of SOD, GSH-Px, GSH and protein-SH were decreased whereas MDA increased, in the liver as well as the lung of the old rats (30 months old) compared to the young rats (2 and 4 months old). The data suggests that the failure of the free radical protective mechanism may be one of the important contributors to the process of ageing.  相似文献   
108.
In this paper, we investigate an application of virtual reality and artificial intelligence (AI) as a technological combination that has a potential to improve the learning experience and engage with the modern generation of students. To address this need, we have created a virtual reality replica of one of humanity's first cities, the city of Uruk and populated this city with AI-controlled 3D avatars, which re-enact everyday life of ancient Sumerians in the period around 3000 B.C. Our hypothesis is that by immersing students into this environment and allowing them to learn by browsing through it and interacting with its virtual citizens can be more engaging and motivating than simply reading the corresponding history text or watching an educational video. To confirm this assumption, we have designed a study with three groups of students. One group was given a historical text about Uruk and everyday life of its citizens (created by our subject matter experts), the second group was shown a documentary video on Uruk and the third group was immersed into virtual Uruk and engaged into interactions with its virtual inhabitants. The outcomes of the study suggest that not only did people in the third group provide much more positive qualitative feedback about the learning experience, but they also showed a better comprehension of the study material by performing (on average) 20% better than the first two groups on the mini-exam that was conducted as a part of this study.  相似文献   
109.
Blood haemoglobin, serum iron, iron binding capacity, transferrin saturation and ferritin levels were determined in two groups of mothers as well as their cords—strict vegetarians (lactovegetarians) and non-vegetarians (omnivores), closely comparable in age, weight, parity and gestation period but differing in their diet and food habits. All these parameters, except total iron binding capacity, were found to be significantly lower in vegetarian mothers and their cords as compared to nonvegetarian mothers and their cords, respectively, despite receiving supplemental iron for six months. Further, there was a greater incidence of anemia and iron deficiency in mothers consuming only vegetarian diet. Moreover, a significant correlation existed between mother's ferritin to cord ferritin confirming that maternal iron deficiency does affect neonatal iron status. All these observations suggest that strict vegetarian mothers as well as their newborns have a greater incidence and risk of anemia and iron deficiency.  相似文献   
110.
目的:本研究旨在测定Scandix pecten-veneris L.的植物素和评价其生物学潜力。方法:测定S.pecten-veneris提取物中植物素的含量,包括生物碱、黄酮、多酚和单宁。使用2,2-二苯基-1-苦肼基(DPPH)测定抗氧化活性;同时通过铁还原/抗氧化能力(FRAP)测定还原能力;使用琼脂扩散测定法评价对七种细菌和四种真菌菌株的抗微生物活性。同时,对脲酶、磷酸二酯酶-Ⅰ和过氧化氢酶-Ⅱ进行酶抑制研究。结论:沙门氏菌显示出适度的抗自由基活性;羟基自由基的潜能降至初始值的20%左右。S.pectenveneris多种提取物的抗氧化活性与总酚含量呈线性相关。S.pecten-veneris叶对金黄色葡萄球菌表现出最高的抑制活性;对白色念珠菌表现出到最高的抗真菌活性。植物提取物对脲酶的活性最有效;对磷酸二酯酶-Ⅰ和碳酸酐酶-Ⅱ显示出中等活性。结果表明,S.pecten-veneris具有良好的药用潜力,可用于治疗一些特定的疾病。  相似文献   
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