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11.
Indian black tea; CTC leaf and dust, produced by Tata Tea Limited, Kolkata, (India) was studiedin vitro as potential scavenger of oxygen free radicals. Super oxide anions were generated in a system containing xanthine—xanthine oxidase (enzymic system) and by NADH- phenozine methosulphate (non enzymic system). Anions were assayed in terms of uric acid formation and reduction of nitroblue tetrazolium salt, which were shown to be suppressed by tea extracts. Extracts from both leaf and dust also inhibted the formation of hydroxyl radicalsin vitro in the enzymic system comprising hypoxanthine—Cu+2—sodium ascorbate and xanthine oxidase and in non enzymic system of deoxyribose—Cu+2—sodium ascorbate and H2O2 as well as the Cu+2 induced lipid peroxidation in human low density lipoprotein. Feeding with black tea in normal rats for sixty days increased their antioxidant activity and their liver microsomes were shown to be protected against peroxidation of lipids as stimulated by metal ions with enzymic or non enzymic reactants. Furthermore feeding with tea extracts in normal as well as triton WR—1339 induced hyperlipidemic rats caused decrease in their plasma levels of total cholesterol, phospholipids and triglycerides. The antioxidant and lipid lowering activities of both extracts from CTC leaf and dust tea was comparable and may be due to the presence of natural products like catechin and others.  相似文献   
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This paper identifies a number of key questions concerning children's understanding of probability. A selection of psychological and pedagogical research studies is evaluated. Attention is drawn to the various definitions of probability assumed by their authors, indicating the relevance of these to an understanding and synthesis of the reported findings. The possibility of basing relevant classroom practice on subjective rather than theoretical concepts of probability is discussed.  相似文献   
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The roots of most land plants establish intimate associations with soil fungi. This association of plant roots with fungi is termed mycorrhiza. It is a marriage between two highly dissimilar organisms based on mutual exchange of nutrients: while the plants provide photosynthetically made carbon compounds to the fungi, the fungi in turn provide to the plants nitrogen and phosphorus scavenged from the breakdown of organic polymers in natural substrates. This mutually beneficial partnership makes possible the green cover on Earth and of all life, ultimately, dependent on plants.  相似文献   
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Purpose: The study aims at finding out relevance and knowledge levels of selected teaching competencies as perceived by educational administrators, faculty and students, in order to assess the training needs of faculty of agricultural universities.

Methodology: Relevance and knowledge levels were tested through a teaching competency questionnaire developed and run on 292 respondents fitting into administrator, faculty and student groups. Needs Assessment Model by Borich [1980. “A Needs Assessment Model for Conducting Follow-up Studies.” Journal of Teacher Education 31 (3): 39–42] is used to identify training needs.

Findings: Results indicate differences in perceptions among groups towards teaching competencies. Prioritized training needs were identified which provide the content and direction for the development of faculty in-service educational programmes.

Practical implications: Faculty of agricultural universities need periodic in-service training programmes in order to improve their teaching competencies so that they become effective and competent teachers in the present educational environment.

Theoretical implications: The statistically validated methodological framework provides for capturing the perception of all stakeholders on the teaching competencies among the faculty members of Agricultural Universities in India, and offers a scope for scaling up the study for similar educational setting in the region.

Originality/value: The perception of students and administrators was also considered along with the self-perception of faculty about the relevance and knowledge levels of teaching competencies.  相似文献   

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H. Ramesh  V. Vinay 《Resonance》1998,3(4):72-87
When can one call a sequence of heads and tails truly random? This article is about the Kolmogorov or algorithmic complexity of a sequence. This complexity tells you how random a sequence is.  相似文献   
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Networks are both imagined and directly experienced. While most people have trouble concretely explaining what networks are and how they structure our world, very few doubt their prominence in an increasingly globalized world where information moves at a dizzying pace. Networks speak to the link between the local and global—linking an event in a small village in Tunisia to the evening news in London. Yet they bind peoples and ideas not only across distance, but also in proximity. How are such networks imagined by peoples across dimensions of class, religion, gender, and generation in the dynamic environment that is revolutionary Egypt today? This article presents initial findings from initial ethnographic and interview-focused fieldwork conducted with Egyptians across a range of demographics. It presents insights around how technological, institutional, and human networks coordinate to present convergent and divergent actions, insights that shape an ever-changing Egyptian political reality.  相似文献   
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Information and communication technology (ICT) development initiatives have begun to acknowledge the power and importance of cultural and community-focused belief systems. Yet the vast majority of such initiatives tend to preidentify developmental goals that communities hold. Paulo Freire's writings have influenced development initiatives by introducing the possibility of working with communities to orient projects. While these “participatory” initiatives have involved soliciting community feedback relative to a research project whose goals were formulated in the university or development institution, they do not go far enough to harness actual visions held by communities. It is important to conceptualize a model and methodology of engaging communities to develop and articulate their own goals of information access and ultimately, an indigenous approach toward cultural, political, and economic aspects of development. This approach holds promise to sustain communities within a return on the investment and efforts of the researcher or institution. This article closes by describing a current initiative in Southern India that reflects the described methodology.  相似文献   
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