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1.
Neuroscientists have believed for a long time that glial cells are supportive elements of the nervous system and have little
role in neuronal function. Despite outnumbering neurons tenfold in the Central Nervous System (CNS), and contributing to more
than half the brain volume, not much attention was paid to these cells. Recently, glial cells have been found to be far more
active participants in CNS function. A set of glial cells, the oligodendrocytes, has attracted attention as their precursors
have been found to be extremely plastic. Though these precursor cells are initially committed to form oligodendrocytes alone,
they can also be induced to form astrocytes and neurons. Such examples of transdetermination are opening up new lines of research
with immense clinical implications. In this part of the series we review some aspects of oligodendrocyte structure and function. 相似文献
2.
E. Margaret Evans Amy N. Spiegel Wendy Gram Brandy N. Frazier Medha Tare Sarah Thompson Judy Diamond 《科学教学研究杂志》2010,47(3):326-353
Museum visitors are an ideal population for assessing the persistence of the conceptual barriers that make it difficult to grasp Darwinian evolutionary theory. In comparison with other members of the public, they are more likely to be interested in natural history, have higher education levels, and be exposed to the relevant content. If museum visitors do not grasp evolutionary principles, it seems unlikely that other members of the general public would do so. In the current study, 32 systematically selected visitors to three Midwest museums of natural history provided detailed open‐ended explanations of biological change in seven diverse organisms. They were not told that these were evolutionary problems. Responses were coded as: informed naturalistic reasoning, featuring some understanding of key evolutionary concepts, novice naturalistic reasoning, featuring intuitive explanations that are also present in childhood, and creationist reasoning, featuring supernatural explanations. All visitors were mixed reasoners, using one or more of these patterns in different permutations across the seven organisms: 72% used a combination of informed naturalistic reasoning and novice naturalistic reasoning, while a further 28% added creationist reasoning to this mix. Correlational analyses indicated that for many visitors these reasoning patterns were coherent rather than fragmented. The theoretical model presented in this article contributes to an analysis of the developmental and cultural factors associated with these patterns. This could help educators working in diverse educational settings understand how to move visitors and students toward more informed reasoning patterns. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47:326–353, 2010 相似文献
3.
Ashavaid T. F. Shalia K. K. Nair K. G. Dalal J. J. 《Indian journal of clinical biochemistry : IJCB》2000,15(1):1-5
The levels of cytotoxic aldehydic products in different culinary oils, with or without thermal stress, (routine domestic or
commercial frying) were determined by thiobarbituric acid method. The results showed that (i) thiobarbituric acid reactivity
was much higher in edible oils rich in polyunsaturated fatty acids than those rich in saturated fatty acids or monounsaturated
fatty acids, even without thermal stress, (ii) the lipid peroxide levels were in proportion to the duration of thermal stress,
(iii) nature of the container used (steel, iron or teflon-coated) had no significant effect on the extent of lipid peroxidation
under identical conditions of thermal stress and (iv) thermally stressed oils collected from hotels and roadside caterers
contained higher levels of cytotoxic aldehydic products, when compared to oils thermally stressed under domestic frying conditions.
These results suggest that dietary ingestion of thermally or autoxidatively stressed polyunsaturated fatty acid rich culinary
oils is more harmful compared with those similarly treated oils rich in saturated fatty acids and monounsaturated fatty acids. 相似文献
4.
Medha Joshi Mumtaz Ali Anwar Midrar Ullah Chandrani Kuruppu 《Health information and libraries journal》2014,31(4):318-324
This is the 12th in a series of articles exploring international trends in health science librarianship. This issue describes developments in health science librarianship in the first decade of the 21st century in South Asia. The three contributors report on challenges facing health science librarians in India, Pakistan and Sri Lanka. There is consensus as to the need for education, training and professional development. Starting in the next issue, the focus will turn to Africa, starting with countries in southern Africa. JM 相似文献
5.
Theodor Schwann, the German physiologist who first propounded the cell theory with M Schieiden, had diverse interests. He
was not only the first to isolate the enzyme pepsin, but also investigated muscle contraction and nerve structure. In the
mid nineteenth century Schwann discovered that a sheath made up of myelin covered the axons of neurons in the peripheral nervous
system (PNS). The cells that form the myelin are today called Schwann cells after him. Today, we know that the Schwann cells
not only form the myelin sheath around neurons, but also regulate several neuronal functions and are an indispensable part
of the PNS. 相似文献
6.
This study examined civic engagement in a sample of 790 undocumented Latinx undergraduates (aged 18–30). The relations between social supports (campus safe spaces and peer support) and civic engagement and whether a strong sense of undocumented identity mediated this relation were examined. Competing statistical models examined the role of participants' status (whether or not they received temporary protection from deportation with Deferred Action for Childhood Arrivals [DACA]) in this mediational process. Results revealed that having a strong identification with being undocumented mediated the role of social supports on civic engagement in the overall sample, and that this process was specifically important for those with DACA status. The intersection of policies such as DACA and the lived experiences of Latinx undocumented college students are discussed. 相似文献
7.
Renawi Abdulrahman Alnajjar Fady Parambil Medha Trabelsi Zouheir Gochoo Munkhjargal Khalid Sumaya Mubin Omar 《Education and Information Technologies》2022,27(4):4753-4770
Education and Information Technologies - Monitoring students' attention and engagement levels in classrooms are critical in promoting an interactive teaching process. Therefore, in addition to... 相似文献
8.
Yousuf Almurtaji John Everatt Nasser S. Almenaye Ahmad S. Alazemi Dalal Abdul Hadi Alradaan 《Emotional and Behavioural Difficulties》2018,23(2):141-153
Previous studies have found significant differences between the classroom behaviour of boys and girls. Most are within a single broad cultural context and little work has been done within an Arabic/Kuwaiti one. The main aim was to investigate the differences in behaviour between boys and girls in Kuwait primary schools. Data were collected that provided comparisons across questionnaires between parent and teacher returns for over 430 students. Separate teacher observations of students (n = 671) and classroom researcher observations were also obtained. Significant differences were found across the scales, indicating higher levels of externalising misbehaviour among boys than girls. A comparison with three studies conducted in other cultural contexts using the same strengths and difficulties instrument as used in this study found similarities and differences in results between the behaviour of boys and girls. 相似文献
9.
Medha Dalal Leanna Archambault Catharyn Shelton 《Journal of Research on Technology in Education》2017,49(3-4):117-133
This mixed-methods study explored the impacts of a semester-long technology professional development for secondary school international teachers from developing nations around the world. We used (a) a survey approach to examine international teachers' perceived technology integration abilities using the technological pedagogical content knowledge (TPACK) framework and (b) a design task to understand their rationale behind technology integration decisions. As a group (N = 16), international teachers reported increased abilities in all TPACK domains. Qualitative analysis of their rationales revealed that though teachers learned to consider the affordances of technology, technology access issues were pivotal in their choice and use of technology in instruction planning. With education becoming increasingly global, the study has implications for the motivation and design of technology professional development programs for international teachers. 相似文献
10.
Ragaa H. M. Salama Diaa El-Deen M. Abdel-Aal Dalal Kh. Eshra Sahar Nagieb Amal F. Arief 《Indian journal of clinical biochemistry : IJCB》2013,28(4):368-373
The effects of environmental tobacco smoke (ETS) are less studied especially on neonates. This study evaluates the clinical and biochemical effects in neonates exposed to ETS during pregnancy. Two hundred pregnant women asked to complete the questioners about their ETS. Ninety from them were enrolled in biochemical assays as two groups according to ETS. The cotinine level determined in saliva and serum of mothers to confirm their tobacco exposure. The routine tracheal suction from the fetus was used to determine the level of neuron specific enolase (NSE), soluble E-cadherin, sApo-1/Fas, nitric oxide (NO) and cotinine. In clinical assessment, the percent of full term babies in non-exposed group (72 %) are higher compared to exposed group (67 %). Apgar score at the first min, admission to intensive care unit (ICU) and morbidity during the first month shows statistical significance increase in exposed compared to non-exposed group (p = 0.03, 0.05, 0.01, respectively). The new born weight in exposed group significantly decreased compared to non-exposed group (2,850 g ± 3.74 vs 2,967.67 g ± 3.34; p = 0.02). In biochemical assessment, NSE and sE-cadherin significantly increased, while NO significantly decreased (p = 0.000) in exposed compared to non-exposed group. There is a positive correlation between level of cotinine and both NSE, sE-cadherin (r = 0.7, 0.9; p = 0.000, 0.006, respectively). To our knowledge, this is the first study link between prenatal tobacco exposure (PTE) and biochemical parameters measured in tracheal suction. PTE will lead to decrease in birth weight most probably by decreasing NO, sFas, and increasing sE-cadherin. While, increased morbidity of neonates in the exposed group could be attributed to cessation of breast feeding and its complication and increased NSE in the studied markers. 相似文献