Glial Cells: The other cells of the nervous system     

Yasmin Khan  Medha S. Rajadhyaksha 《Resonance》2002,7(8):8-15

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   

Brain type natriuretic peptide (BNP)—A marker of new millennium in diagnosis of congestive heart failure   总被引：1，自引：0，他引：1  

Arun Raizada  Suman Bhandari  Muzaiyan Ahmed Khan  Harsh Vardhan Singh  Sherin Thomas  Vikram Sarabhai  Neelima Singh  Naresh Trehan 《Indian journal of clinical biochemistry : IJCB》2007,22(1):4-9

The burden of disease in patients with congestive heart failure is high. The future of BNP looks promising as it may be a better diagnostic tool for the diagnosis of CHF in developing countries in new millennium. Natriuretic peptide hormones, a family of vasoactive peptides with many favourable physiological properties, have emerged as important contenders for development of diagnostic tools and therapeutic agents in cardiovascular disease. Measurement of B-type natriuretic peptide has become as an easy-to-perform bedside test. The clinical and diagnostic significance of the measurement of plasma Nt-proBNP in the diseases of the cardiovascular system with particular emphasis on the assessment of patients with heart failure and their effects on predicting survival rate. The plasma levels of Nt-proBrain Natriuretic peptide responds more vigorously after myocardial infarction than those of other natriuretic peptides. This article is an attempt to give a short overview on the utility of BNP-blood levels for the diagnosis and treatment of heart failure  相似文献   

The case in case-based design of educational software: A methodological interrogation     

S. Khan 《Educational technology research and development : ETR & D》2008,56(4):423-447

This research assessed the value of case study methodology in the design of an educational computer simulation. Three sources of knowledge were compared to assess the value of case study: practitioner and programmer knowledge, disciplinary knowledge, and knowledge obtained from a case study of teacher practice. A retrospective analysis revealed that the case study was the source of 16 out of 23 design decisions and therefore was the most significant influence on the design of the simulation. The case study was particularly effective in sensitizing the design team to the classroom context, identifying common and uncommon teacher practices, revealing unexpected dimensions of interactions in the classroom, and generating constructive changes to the design of the simulation. Case studies can significantly enrich the design of educational software and are a promising methodological choice for design teams.

S. KhanEmail:

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Impact of teachers’ professional development on school improvement—an analysis at Bangladesh standpoint   总被引：1，自引：0，他引：1  

Kazi Enamul Hoque  Gazi Mahabubul Alam  Abdul Ghani Kanesean Abdullah 《Asia Pacific Education Review》2011,12(3):337-348

This study seeks to describe the teachers’ professional development activities in Bangladesh and explores the hypotheses about the relationship between teachers’ traditional professional development activities and school improvement. Data from a representative sample of City secondary schools from Bangladesh (n = 127) were gathered through questionnaires from 127 principals and 694 teachers. Hierarchical multiple regression analysis was used in this research. This study found significant impacts of some of teachers’ professional development activities on school improvement. Also found that the maximum school improvement can be achieved if schools put more emphasis on teachers’ collaboration, in-service training and classroom observation and less emphasis on individual action enquiry. The findings of this study provide important information for the policy makers, educational managers and especially for the headmasters and teachers concerned with the improvement of teachers’ quality in secondary schools of Bangladesh. This study adopts a concurrent approach of data collection and analysis.  相似文献   

What��s Missing in Model-Based Teaching     

Samia Khan 《Journal of Science Teacher Education》2011,22(6):535-560

In this study, the author investigated how four science teachers employed model-based teaching (MBT) over a 1-year period. The purpose of the research was to develop a baseline of the fundamental and specific dimensions of MBT that are present and absent in science teaching. Teacher interviews, classroom observations, and pre and post-student assessments were gathered. Using a Generate-Evaluate-Modify framework as a theoretical guide, the author identified three fundamental aspects of MBT that were not apparent in an analysis of the teaching methods. Drawing on these findings, the author hypothesizes the consequent impact of the absence of these aspects on MBT on students?? experiences and performance in science. Implications for core science teacher professional development activities on MBT are discussed.  相似文献   

Extraction of DNA suitable for PCR applications from mature leaves of Mangifera indica L.     

Muhammad Abubakkar Azmat  Iqrar Ahmad Khan  Hafiza Masooma Naseer Cheema  Ishtiaq Ahmad Rajwana  Ahmad Sattar Khan  Asif Ali Khan 《Journal of Zhejiang University. Science. B》2012,13(4):239-243

Good quality deoxyribonucleic acid (DNA) is the pre-requisite for its downstream applications. The presence of high concentrations of polysaccharides, polyphenols, proteins, and other secondary me- tabolites in mango leaves poses problem in getting good quality DNA fit for polymerase chain reaction (PCR) applications. The problem is exacerbated when DNA is extracted from mature mango leaves. A reliable and modified protocol based on the cetyl- trimethylammonium bromide (CTAB) method for DNA extraction from mature mango leaves is described here. High concentrations of inert salt were used to remove polysaccharides; Polyvinylpyrrolidone (PVP) and β-mercaptoethanol were employed to manage phenolic compounds. Extended chloroform-isoamyl alcohol treatment followed by RNase treatment yielded 950?1050 μg of good quality DNA, free of protein and RNA. The problems of DNA degradation,contamination, and low yield due to irreversible binding of phenolic compounds and coprecipitation of polysaccharides with DNA were avoided by this method. The DNA isolated by the modified method showed good PCR amplification using simple se- quence repeat (SSR) primers. This modified protocol can also be used to extract DNA from other woody plants having similar problems.  相似文献   

Suppressing Memory and Knowledge: A Self-taught Pedagogy     

Abdul Jabbar 《Changing English: An International Journal of English Teaching》2012,19(3):307-312

This article contextualizes the significance of lived experience in relation to personal narratives and learning largely by examining Zainab Salbi’s autobiography Between Two Worlds: Escape from Tyranny: Growing Up in the Shadow of Saddam. Discussing Salbi’s education and personal life as the daughter of Saddam’s private pilot, the article explores the learner’s reluctance to share what Donald Winnicott calls ‘the secret self’. This resistance on the part of the learner complicates the notion of communication as a therapeutic method that educators usually use as the bases for teaching and learning, as explicated by Alice Pitt. In Salbi’s politicized world, she explains how suppressed memory and reluctance to express oneself are tools of survival that ultimately turn into a lifestyle inside and outside the classroom. By employing Winnicott’s metaphor of hide and seek to demonstrate ambivalence in communication, this study explores how Salbi’s experience as a woman with a suppressed personal history can culturally and psychologically be very similar to teachers and students who are reluctant to share their own memories. In effect, this paper examines the implications of suppressed memory and knowledge among reluctant learners for pedagogical practices worldwide.  相似文献   

Contextual influences on sources of academic self-efficacy: a validation with secondary school students of Kerala     

K. Abdul Gafoor  P. Muhammed Ashraf 《Asia Pacific Education Review》2012,13(4):607-616

This study investigates the theorized sources of Academic Self-Efficacy among the higher secondary school students of Kerala, India. Mastery Experience in the form of Academic Achievement, vicarious experience in the form of School Image and Social Persuasion in the form of Parental Encouragement are included as the predictor variables of Academic Self-Efficacy. Participants in the present study were 700 higher secondary school students of Kerala, selected using stratified random sampling. The findings of the study confirm the theorized correlation of Academic Self-Efficacy with previous achievement, vicarious experience (school image) and persuasory information (parental encouragement). In the total sample, the percent of variance in Academic Self-Efficacy that is predictable by the three-predictor variables is nearly one quarter (23.83?%). School Image is the best contributing variable (9.42?%) followed by Mastery Experience (8.67?%) and then by Parental Encouragement (5.74?%). The findings shows that apart from cultural differences, locale and gender difference also exist in sources of Academic Self-Efficacy. The superiority of School Image over Mastery Experience in predicting Academic Self-Efficacy is different from that found in the West, theoretically and empirically. In India, self-efficacy beliefs of youngsters continue to depend more on social and domestic factors than personal experience and mastery.  相似文献   

Frictions that activate change: dynamics of global to local non-governmental organizations for female education and empowerment in China,India, and Pakistan*     

Vilma Seeberg  Supriya Baily  Asima Khan  Heidi Ross  Yimin Wang  Payal Shah 《Asia Pacific Journal of Education》2017,37(2):232-247

This article examines how non-governmental organizations create resources and spaces for girls and women’s education and empowerment in China, India and Pakistan – in the context of global expectations and local state relations as well as cultural norms. We examine the dynamics that foster female empowerment associated with educational attainment. Analysis showed that the five NGO’s responses to enabling and constraining local needs and demands gave rise to productive friction that activated positive development. We conclude that engaging local individuals as managers, teachers or facilitators who can negotiate with international actors and with the state is an effective foundation for maintaining a balance between being accountable to local contingencies and norms and to global social justice principles of the projects. These models indicated that “effective scale” might better be defined as a collaboration between the local and global, rather than “scaling up” in size.

International NGO partnerships with several of state organizations and local leadership can be a catalyst for fundamental change, subject to dynamic engagement with productive friction that activates educational empowerment and social change.  相似文献   

Additive effects due to biochar and endophyte application enable soybean to enhance nutrient uptake and modulate nutritional parameters     

Muhammad Waqas  Yoon-Ha Kim  Abdul Latif Khan  Raheem Shahzad  Sajjad Asaf  Muhammad Hamayun  Sang-Mo Kang  Muhammad Aaqil Khan  In-Jung Lee 《Journal of Zhejiang University. Science. B》2017,18(2):109-124

We studied the effects of hardwood-derived biochar (BC) and the phytohormone-producing endophyte Galactomyces geotrichum WLL1 in soybean (Glycine max (L.) Merr.) with respect to basic, macro- and micronutrient uptakes and assimilations, and their subsequent effects on the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and 1,1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging activity. The assimilation of basic nutrients such as nitrogen was up-regulated, leaving carbon, oxygen, and hydrogen unaffected in BC+G. geotrichum-treated soybean plants. In comparison, the uptakes of macro- and micronutrients fluctuated in the individual or co-application of BC and G. geotrichum in soybean plant organs and rhizospheric substrate. Moreover, the same attribute was recorded for the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and DPPH-scavenging activity. Collectively, these results showed that BC+G. geotrichum-treated soybean yielded better results than did the plants treated with individual applications. It was concluded that BC is an additional nutriment source and that the G. geotrichum acts as a plant biostimulating source and the effects of both are additive towards plant growth promotion. Strategies involving the incorporation of BC and endophytic symbiosis may help achieve eco-friendly agricultural production, thus reducing the excessive use of chemical agents.  相似文献