13,455 research outputs found
Two-stage hands-on technology activity to develop preservice teachers’ competency in applying science and mathematics concepts
This paper discusses the implementation of a two-stage hands-on technology learning activity, based on Dewey’s learning experience theory that is designed to enhance preservice teachers’ primary and secondary experiences in developing their competency to solve hands-on problems that apply science and mathematics concepts. The major conclusions were that: (1) preservice teachers understood the science and mathematics concepts related to the hands-on activity, but they need more help in exploring practical products of applying discipline related concepts for the purpose of stimulating their design ideas; and (2) the two-stage hands-on technology learning activity served as useful prompts in developing preservice teachers’ primary and secondary experiences in applying science and mathematics concepts during the design process. However, it was evident that preservice teachers still needed more training in improving their design ideas by the application of more in-depth related science and mathematics concepts
Teacher and student reflections on ICT-rich science inquiry
Background: Inquiry learning in science provides authentic and relevant contexts in which students can create knowledge to solve problems, make decisions and find solutions to issues in today’s world. The use of electronic networks can facilitate this interaction, dialogue and sharing, and adds a new dimension to classroom pedagogy. Purpose: This is a report of teacher and student reflections on some of the tensions, reconciliations and feelings they experienced as they worked together to engage in inquiry learning. The study sought to find out how networked ICT use might offer new and different ways for students to engage with, explore and communicate science ideas within inquiry. Sample: This project developed case studies with 6 science teachers of year 9 and 10 students, with an average age of 13 and 14 years in three New Zealand high schools. Teacher participants in the project had varying levels of understanding and experience with inquiry learning in science. Teacher knowledge and experience with ICT were equally diverse. Design and Methods: Teachers and researchers developed initially in a joint workshop a shared understanding of inquiry, and how this could be enacted. During implementation, the researchers observed the inquiry projects in the classrooms and then, together with the teachers, reviewed and analysed the data that had been collected. Results: At the beginning of the project, some of the teachers and students were tentative: inquiry based teaching supported by ICT meant initially that the teachers were hesitant in letting go some of the control they felt they had over students learning, and the students felt insecure in adopting some responsibility for their own learning. Over time a sense of trust and ease developed and this ‘control of learning’ balance moved from what was traditionally accepted, but not without modifications and reservations. Conclusions: There is no clear pathway to follow in moving towards ICT-supported science inquiry in secondary schools. The experience of the teacher, the funds of knowledge the students bring to the classroom, the level of technological availability in the school and the ability of the students are all variables which determine the nature of the experience
Inter-individual variation in nucleotide excision repair in young adults: effects of age, adiposity, micronutrient supplementation and genotype
Nucleotide excision repair (NER) is responsible for repairing bulky helix-distorting DNA lesions and is essential for the maintenance of genomic integrity. Severe hereditary impairment of NER leads to cancers such as those in xeroderma pigmentosum, and more moderate reductions in NER capacity have been associated with an increased cancer risk. Diet is a proven modifier of cancer risk but few studies have investigated the potential relationships between diet and NER. In the present study, the plasmid-based host cell reactivation assay was used to measure the NER capacity in peripheral blood mononuclear cells from fifty-seven volunteers aged 18–30 years before and after 6 weeks of supplementation with micronutrients (selenium and vitamins A, C and E). As a control, nine individuals remained unsupplemented over the same period. Volunteers were genotyped for the following polymorphisms in NER genes: ERCC5 Asp1104His (rs17655); XPC Lys939Gln (rs2228001); ERCC2 Lys751Gnl (rs13181); XPC PAT (an 83 bp poly A/T insertion–deletion polymorphism in the XPC gene). NER capacity varied 11-fold between individuals and was inversely associated with age and endogenous DNA strand breaks. For the first time, we observed an inverse association between adiposity and NER. No single polymorphism was associated with the NER capacity, although significant gene–gene interactions were observed between XPC Lys939Gln and ERCC5 Asp1104His and XPC Lys939Gln and ERCC2 Lys751Gnl. While there was no detectable effect of micronutrient supplementation on NER capacity, there was evidence that the effect of fruit intake on the NER capacity may be modulated by the ERCC2 Lys751Gnl single nucleotide polymorphism
Training for recovery:impact of sprint interval training on recovery dynamics and aerobic performance in kickboxing athletes
PurposeRecovery within and between rounds is crucial to combat sports performance. We sought to determine whether sprint interval training (SIT) improves recovery dynamics and aerobic performance.MethodsEleven male kickboxing athletes (26 ± 5 years; body mass index 25 ± 3 kg/m2) were recruited. Participants were tested three times for VO2peak/time to exhaustion and critical power; baseline, 3 weeks control, 3 weeks of SIT (8 × 10 s lower body sprints followed by a maximum of 10 min recovery before completing 8 × 10 s upper body sprints). During SIT session 1 and 9 continuous gas analysis was performed.ResultsThere was a significant reduction in recovery time between lower and upper body sprints with training (session 1: 441 ± 150 s; session 9: 268 ± 10 s; P < 0.01; d = 2.77) and change in oxygen off-kinetics amplitude (session1: 3.0 ± 0.7 L/min, session 9: 3.6 ± 1.0 L/min; P < 0.05; d = − 1.77), VO2 end (session 1: 0.59 ± 0.19 L/min, session 9: 0.81 ± 0.21 L/min; P < 0.05, d = − 0.90), time constant (session 1: 81 ± 21 s; session 9: 60 ± 11 s; P < 0.05; d = 1.03). Following training there was a significant improvement in critical power (P < 0.05; η2p = 0.72) time to exhaustion (P < 0.05; η2p = 0.30) but not VO2peak (P > 0.05).ConclusionSIT improves recovery time associated and aerobic performance associated with improved oxygen off-kinetics. Therefore, training needs to focus on improving oxygen off-kinetics to enhance combat performance
A STUDY ON THE PROXIMATE ANALYSIS OF HYDROGENATED FAT IN BAKERY PRODUCTS
Margarine is an important functional ingredient for several bakery and confectionary products. It places a major role in the organoleptic attributes of these bakery products. This article contextualizes on “Bakery Products” available in Indian market. It is analyzed and tested through laboratory using various methods of test such as phytochemical screening, proximate analysis, and elemental analysis which are the major laboratory test done. In that subcategory test such as flavonoids, tannis, alkaloids, polyphenols etc. In that, each product is sampled, analyzed, and tested by chemical to know the exact quantity and the quality of various ingredients of the product and to know how much it is important for that packet products manufacturer
Rep-tiling for triangles
AbstractIn this paper we prove that one can only tile a triangle with tiles all congruent to each other and similar to the original triangle when k2, l2 + k2, or 3k2 tiles are used. The result is based on the geometry of packing and a result of I. Niven's on rational trigonometric values. In addition we describe how to tile most triangles
Organophosphorus and organo-inorganic hybrid fire retardant coatings for polymers
Thin coatings of crosslinked poly(vinylphosphonic acid) display good adhesion and excellent
fire-retardant barrier properties when applied to the surfaces of a typical thermoplastic, such as
poly(methyl methacrylate), but perform relatively poorly in water-soak tests. Water-soak test
performance can be significantly improved however by various hydrophobic modifications
without detriment to fire performance
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