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Senthil Kumar  Laxminarain  Dipanjan Ghosh 《Resonance》2006,11(5):90-91

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Efficient Degumming of Rice Bran Oil by Immobilized PLA1 from Thermomyces lanuginosus     

Tripti Singhania  Harsh Sinha  Paulomi Das  Amit Kumar Mukherjee 《Food Technology and Biotechnology》2015,53(1):91-95

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Synthetic and biological studies on a cyclopolypeptide of plant origin     

Dahiya R  Kumar A 《Journal of Zhejiang University. Science. B》2008,9(5):391-400

Objective: A natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling oftetrapep-tide units Boc-Leu-Pro-Trp-Leu-Ome and Boc-Ile-Ala-Ala-Gly-Ome after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.Methods: Solution phase technique was adopted for the synthesis of cyclooctapeptide--sarcodactylamide.Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz.Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-Ome and Ala-Gly-Ome.Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method.The structure of synthesized cyclopolypeptide was elucidated by FTIR,1H NMR,13C NMR,FABMS spectral data and elemental analysis.The newly synthesized peptide was evaluated for dif-ferent pharmacological activities including antimicrobial,anthelmintic and cytotoxic activities.Results: Synthesis of sarcodac-tylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent.Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines,in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses and Eudrilus sp.Moreover,cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa,in comparison to standard drugs griseofulvin and ciprofloxacin.Conclusion: Solution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide.N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine.  相似文献   

An Empirical Investigation Demonstrating the Multidimensional DIF Paradigm: A Cognitive Explanation for DIF     

Cindy M. Walker  S. Natasha Beretvas 《Journal of Educational Measurement》2001,38(2):147-163

Differential Item Functioning (DIF) is traditionally used to identify different item performance patterns between intact groups, most commonly involving race or sex comparisons. This study advocates expanding the utility of DIF as a step in construct validation. Rather than grouping examinees based on cultural differences, the reference and focal groups are chosen from two extremes along a distinct cognitive dimension that is hypothesized to supplement the dominant latent trait being measured. Specifically, this study investigates DIF between proficient and non-proficient fourth- and seventh-grade writers on open-ended mathematics test items that require students to communicate about mathematics. It is suggested that the occurrence of DIF in this situation actually enhances, rather than detracts from, the construct validity of the test because, according to the National Council of Teachers of Mathematics (NCTM), mathematical communication is an important component of mathematical ability, the dominant construct being assessed. However, the presence of DIF influences the validity of inferences that can be made from test scores and suggests that two scores should be reported, one for general mathematical ability and one for mathematical communication. The fact that currently only one test score is reported, a simple composite of scores on multiple-choice and open-ended items, may lead to incorrect decisions being made about examinees.  相似文献   

Heisenberg’s invention of matrices     

Pradeep Kumar 《Resonance》2017,22(4):399-405

Richard Feynman once said: “nobody understands quantum mechanics”. Still, those who devised it are perhaps the ones closest to understanding their creation. It suggests that whenever the weirdness of quantum mechanics haunts you, it is better to go back to its creators in terms of their original publications. In the present article, the author has tried to seek help from Heisenberg’s 1925 paper, in order to reduce the weirdness of going from classical observables to quantum operators.  相似文献   

Peer facilitated writing groups: a programmatic approach to doctoral student writing     

Vijay Kumar  Claire Aitchison 《Teaching in Higher Education》2018,23(3):360-373

Very few empirical studies have investigated programmes in which doctoral students act as peer facilitators in faculty writing groups. We report on the development of a centrally delivered doctoral student writing programme in which twenty student participants were mentored and provided with the resources to initiate their own faculty-based doctoral writing groups. ‘Legitimate peripheral participation’ was used as a conceptual lens to interpret the data collected during the establishment and evaluation of the programme. All student participants in the preparatory training course, which was developed in consultation with postgraduate students and research supervisors, went on to become doctoral writing peer facilitators of peer writing groups. Insights from seven of these showed how a well-structured and supportive programme harnessed the benefits of peer learning by bringing personal rewards to participants and building institutional capacity around doctoral research writing literacies.  相似文献   

Three dimensional couette flow and heat transfer through a porous medium with variable permeability     

Chaudhary?R.?C.?Email author  Sharma?Pawan?Kumar 《浙江大学学报(A卷英文版)》2003,4(2):181-185

This paper reports research on the effects of variations in injection velocity and permeability on the heat transfer and flow through a highly porous medium between two horizontal parallel plates situated at constant distance with constant suction by the upper plate. Due to this type of variation in injection velocity and in permeability the flow becomes three dimensional. The governing equations are solved by adopting complex variable notations to obtain the expressions for the velocity and temperature field. The skin-friction along the main flow direction and rate of heat transfer are discussed with the help of graphs.  相似文献   

Erratum to: Effect of Current Electricity Simulation Supported Learning on the Conceptual Understanding of Elementary and Secondary Teachers     

David Devraj Kumar  P. V. Thomas  John D. Morris  Karen M. Tobias  Mary Baker  Trudy Jermanovich 《Journal of Science Education and Technology》2011,20(2):116-115

This study examined the impact of computer simulation and supported science learning on a teacher’s understanding and conceptual knowledge of current electricity. Pre/Post tests were used to measure the teachers’ concept attainment. Overall, there was a significant and large knowledge difference effect from Pre to Post test. Two interesting interactions were observed during the data analysis. The first was the difference between Elementary and Secondary teachers. Both groups had significant gains, with large effect sizes, but the Elementary teachers (Pre-Mean = 3.70, Post-Mean = 7.51) started lower and ended higher exhibiting a significantly larger gain than the Secondary teachers (Pre-Mean = 4.96, Post-Mean = 6.71). The second interaction was the impact of gender. Both groups showed significant gains, with large effect sizes, but females (Pre-Mean = 3.90, Post-Mean = 7.21) gained significantly more than males (Pre-Mean = 5.13, Post-Mean = 7.01). These results confirm that computer simulation supported science learning can have a positive effect on concept attainment in teachers.  相似文献   

Test Item Analysis＂ An Educator Professionalism Approach     

Mohd Sahandri Gani Hamzah  Saifuddin Kumar Abdullah 《美中教育评论》2011,(3):307-322

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Scientific Collaboration with Educators: Practical Insights from an in‐Class Noise‐Reduction Intervention     

Jessica Massonni  Philippe Frasseto  Denis Mareschal  Natasha Z. Kirkham 《Mind, Brain, and Education》2020,14(3):303-316

Moving the field of Mind, Brain, and Education forward requires researchers and educators to reframe the boundaries of their own discipline in order to create knowledge that is both scientifically based, and of practical relevance for education. We believe that this could be done by co‐constructing research projects from the start. We present a case study of a noise‐reduction intervention in elementary classrooms, in which teachers and researchers worked together from the onset of study design. We examine the processes behind: (1) selecting research questions and measures, (2) planning interventions, (3) receiving ethical approval and funding, (4) recruiting schools, and (5) collecting data. At each step, our study provides suggestions for future collaborative efforts, keeping in mind broader theoretical and methodological implications. We believe that our concrete examples and suggestions will be useful for beginning and confirmed researchers, as well as teachers aiming to know more about research projects.  相似文献