960 resultados para Educational differences
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IEEE, IEEE Comp Soc, Tech Council Software Engn
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The purpose of the present work is to investigate the compositional difference of polypropylene-polyethylene block copolymers (PP-b-PE) manufactured industrially by the process of degradation and hydrogenation, respectively. Each of the PP-b-PE copolymers was fractionated into three fractions with heptane and chloroform. The compositions of the three fractions were characterized by C-13 nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy, as well as differential scanning calorimetry (DSC) and thermal fractionation. The results showed that the Chloroform-soluble fraction was amorphous ethylene-propylene rubber, and the content of the rubber in PP-b-PE manufactured by hydrogenation was less than that by degradation. The degree of crystallinity of the chloroform-insoluble fraction of the PP-b-PE manufactured by hydrogenation is higher than that of by degradation.
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Karyotype and chromosomal location of the major ribosomal RNA genes (rDNA) were studied using fluorescence in situ hybridization (FISH) in five species of Crassostrea: three Asian-Pacific species (C. gigas, C. plicatula, and C. ariakensis) and two Atlantic species (C. virginica and C. rhizophorae). FISH probes were made by PCR amplification of the intergenic transcribed spacer between the 18S and 5.8S rRNA genes, and labeled with digoxigenin-11-dUTP. All five species had a haploid number of 10 chromosomes. The Atlantic species had 1-2 submetacentric chromosomes, while the three Pacific species had none. FISH with metaphase chromosomes detected a single telomeric locus for rDNA in all five species without any variation. In all three Pacific species, rDNA was located on the long arm of Chromosome 10 (10q)-the smallest chromosome. In the two Atlantic species, rDNA was located on the short arm of Chromosome 2 (2p)-the second longest chromosome. A review of other studies reveals the same distribution of NOR sites (putative rDNA loci) in three other species: on 10q in C. sikamea and C. angulata from the Pacific Ocean and on 2p in C. gasar from the western Atlantic. All data support the conclusion that differences in size and shape of the rDNA-bearing chromosome represent a major divide between Asian-Pacific and Atlantic species of Crassostrea. This finding suggests that chromosomal divergence can occur under seemingly conserved karyotypes and may play a role in reproductive isolation and speciation.
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Two strains of Penicillium, DQ25 and SC10, isolated from marine sponge Haliclona angulata (Bowerbank) and Hymeniacidon sp. respectively, were subjected to stationary cultivation under GYP medium for 30 days. The fermentation extracts were undergone bioactivities assays against human pathogens, phytopathogenic fungi and brine shrimp (Artemia salina). Bioassays-guided compounds isolation was performed by Silica gel columns and Sephadex LH-20 chromatography. Spectroscopic methods were used to structures elucidation of the compounds. Results showed the activities of secondary metabolites of strain DQ25 were generally stronger than that of strain SC10. Major bioactive molecules isolated from strain DQ25 were a 1,4-naphthoquinone derivative and an unidentified alkaloid. The two components were not isolated from the extract of strain SC10. ITS sequences revealed that these two species have the greatest similarity with Penicillium vinaceum and Penicillium granulatum respectively.
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In many plant species, leaf morphology varies with altitude, an effect that has been attributed to temperature. It remains uncertain whether such a trend applies equally to juvenile and mature trees across altitudinal gradients in semi-arid mountain regions. We examined altitude-related differences in a variety of needle characteristics of juvenile (2-m tall) and mature (5-m tall) alpine spruce (Picea crassifolia Kom.) trees growing at altitudes between 2501 and 3450 m in the Qilian Mountains of northwest China. We found that stable carbon isotope composition (delta C-13), area- and mass-based leaf nitrogen concentration (N-a, N-m), number of stomata per gram of nitrogen (St/N), number of stomata per unit leaf mass (St/LM), projected leaf area per 100 needles (LA) and leaf mass per unit area (LMA) varied nonlinearly with altitude for both juvenile and mature trees, with a relationship reversal point at about 3 100 m. Stomatal density (SD) of juvenile trees remained unchanged with altitude, whereas SD and stomatal number per unit length (SNL) of mature spruce initially increased with altitude, but subsequently decreased. Although several measured indices were generally found to be higher in mature trees than in juvenile trees, N-m, leaf carbon concentration (C.), leaf water concentration. (LWC), St/N, LA and St/LM showed inconsistent differences between trees of different ages along the altitudinal gradient. In both juvenile and mature trees, VC correlated significantly with LMA, N-m, N-a, SNL, St/LM and St/N. Stomatal density, LWC and LA were only significantly correlated with delta C-13 in mature trees. These findings suggest that there are distinct ecophysiological differences between the needles of juvenile and mature trees that determine their response to changes in altitude in semi-arid mountainous regions. Variations in the fitness of forests of different ages may have important implications for modeling forest responses to changes in environmental conditions, such as predicted future temperature increases in high attitude areas associated with climate change.
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There is a debate in cognitive development theory on whether cognitive development is general or specific. More and more researchers think that cognitive development is domain specific. People start to investigate preschoolers' native theory of human being's basic knowledge systems. Naive biology is one of the core domains. But there is argument whether there is separate native biological concepts among preschoolers. The research examined preschoolers' cognitive development of naive biological theory on two levels which is "growth" and "aliveness", and it also examined individual difference and factors that lead to the difference. Three studies were designed. Study 1 was to study preschoolers' cognition on growth, which is a basic trait of living things, and whether children can distinguish living and non-living things with the trait and understanding the causality. Study 2 was to investigate preschoolers' distinction between living things and non-living things from an integrated level. Study 3 was to investigate how children make inferences to unfamiliar things with their domain specific knowledge. The results showed the following: 1. Preschoolers gradually developed naive theory of biology on growth level, but their naive theory on integrated level has not developed. 2 Preschoolers' naive theory of biology is not "all or none", 4- and 5-year-old children showed some distinction between living and non-living things to some extent, they use non-intentional reason to explain the cause of growth and their explanation showed coherence. But growth has not been a criteria of ontological distinction of living and non-living things for 4- and 5-year-old children, most 6-year-old children can distinguish between living and non-living things, and these show the developing process of biological cognition. 3. Preschoolers' biological inference is influenced by their domain-specific knowledge, whether they can make inference to new trait of living things depends on whether they have specific knowledge. In the deductive task, children use their knowledge to make inference to unfamiliar things. 4-year-olds use concrete knowledge more often while the 6-year-old use generalized knowledge more frequency. 4. Preschoolers' knowledge grow with age, but individuals' cognitive development speed at different period. Urban and rural educational background affect cognitive performance. As time goes by, the urban-rural knowledge difference to distinguish living and nonliving things reduces. And preschoolers' are at the same developmental stage because the three age groups have similar causal explanation both in quantity and quality. 5. There is intra-individual difference on preschoolers' naive biological cognition. They show different performance on different tasks and domains, and their cognitive development is sequential, they understand growth earlier than they understand "alive", which is an integrated concept. The intra-individual differences decrease with age.
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It is well established that memory functioning deteriorates with advancing age. However, research indicates that the magnitude of age-related memory deficits varies across different types of memory, and broad individual differences can be observed in the rate and timing of memory aging. The general aim of this study was to investigate the selectivity and variability of memory functioning in relation to anxiety. Firstly, memory effectiveness was assessed in episodic memory tasks with reality monitoring and external source monitoring paradigms, semantic memory tasks referred to general knowledge and word fluency, and perceptual priming task reflected in word completion. According to the scores on trait version of STAI, the high-trait and low-trait anxious subjects were screened respectively from young and old participants matched for educational level. Secondly, based on the results of the first part, concurrent primary and secondary tasks with probe technique assessing spare processing capacity were used to explore the relation between memory efficiency and anxiety. The first main findings were that: (a) there were no age-related differences in semantic memory assessed by general knowledge and PRS, whereas age effects were observed in episodic memory and semantic memory assessed by word fluency with stringent time restraints. (b) Furthermore, comparison of age-related deficits in source and item was not related to the presentation ways and encoding effort for source, but was affected by types of source. Specifically, memory was more sensitive to aging than item memory in external source monitoring processes involved in discriminating two external sources (i.e., female vs. male voices), but not in reality monitoring processes in discriminating between internal and external sources (i.e., acting vs. listening). The second main findings were that: (a) Anxiety had no effects on the effectiveness and efficiency of semantic memory in recall of general knowledge and PRS, but impaired those of semantic memory in word fluency. (b) The effects of anxiety on episodic memory were different between the old and the young. Both the effectiveness and the efficiency of episodic memory of the old were affected adversely by anxiety. More importantly, source recall in external source monitoring processes was observed to be more vulnerable to anxiety than item memory. The effectiveness of episodic memory of the young was relatively unrelated to anxiety, while anxiety might have adverse effect on their memory efficiency. These results indicated that: First, the selectivity of age-related memory deficits existed not only between memory systems, but also within episodic memory system. The tendency to forget the source even when the fact was retained in external source monitoring was suggested to be a specific feature of cognitive aging. Second, anxiety had adverse impact on the individual differences in memory aging, and mediated partial age-related differences in episodic memory performance.
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From the organizational behavior point, this study initially explored how factors of educational changes influenced on teachers. This study adapted the questionnaire made up by Consortium for Cross-Culture Research in Education (CCCRE), by cooperating with other countries, interviewed 513 teachers in nine countries. The main results are as follows: 1. Factors of educational changes include: domain, origin, objective, teachers' role, and timetable. Comparative results show: More similarities than differences tend to be presented in five factors. The detail results are: in domain, it mainly involves teaching change and learning outcomes change; in origin, the educational change most teachers participated was initialed by government; in role, teachers more act as the implementer; in timetable, gradual development is the chief characteristic. 2. The domain of change, origin and teachers' role has a significant impact on the quality of worklife of teachers, but timetable of change has not. The further study about the influence of educational origin on the quality of worklife of teachers shows: Changes of teachers' time -using, professional development were significantly impacted by the origin of education, and there is a significant difference in the change of time-using among nine countries. 3. Change on students, change on teachers' relationship are two important factors to impact the teachers' evaluation about educational change. But the teachers' evaluation, teaching age and the change on relationship are valid factors to predicate teachers participate in next educational change. 4. Compared with the educational change of other eight countries, the change in school system management and the change in learning outcomes are more carried on in China. There is no significance about other factors between China and overall nine countries. In China, the educational change has a more positive impact on teachers' time-using and professional development, but professional development is also a important factor to impact teachers' evaluation on change; however there is a negative relationship between the Chinese teachers' evaluation and the teachers' participation in next change.
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Much has been published in recent years about the desirable nature of facilitated interactions in on-line discussions with educational purposes. However little has been reported about the roles which tutors actually adopt in real life learning contexts, how these range between ‘tutoring, ‘managing’ and ‘facilitating’, and what the distinctions between these three roles may be. In this paper choices of priorities in e-moderation, which were made in three naturalistic (real life) case studies by three higher education practitioners, are identified and discussed. These contrasting approaches were captured and analysed using grounded theory principles. The paper also discusses these occasions when the facilitation was less effective than might have been desired. It finally summarises the potential of various approaches within e-moderation – and some of the attendant risks. The finding is that principles and practices developed for face-to-face support of student-directed learning were found equally applicable in e-moderated online group work, despite several significant differences between the two types of setting. Keywords: higher education, e-learning, e-moderation, asynchronous discussions, learning outcomes, grounded theory
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Special Educational Needs in Wales (with K Williams and B Rainey), (2004) 3 Wales Journal of Law and Policy 17-33. RAE2008
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James Macduff, Neil Raistrick and Mervyn Humphreys (2002). Differences in growth and nitrogen productivity between a stay-green genotype and a wild-type of Lolium perenne under limiting relative addition rates of nitrate supply. Physiologia Plantarum, 116 (1), 52-61. Sponsorship: BBSRC RAE2008
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Traditional methods for phenotyping skeletal muscle (e.g., immunohistochemistry) are labor-intensive and ill-suited to multixplex analysis, i.e., assays must be performed in a series. Addressing these concerns represents a largely unmet research need but more comprehensive parallel analysis of myofibrillar proteins could advance knowledge regarding age- and activity-dependent changes in human muscle. We report a label-free, semi-automated and time efficient LC-MS proteomic workflow for phenotyping the myofibrillar proteome. Application of this workflow in old and young as well as trained and untrained human skeletal muscle yielded several novel observations that were subsequently verified by multiple reaction monitoring (MRM).We report novel data demonstrating that human ageing is associated with lesser myosin light chain 1 content and greater myosin light chain 3 content, consistent with an age-related reduction in type II muscle fibers. We also disambiguate conflicting data regarding myosin regulatory light chain, revealing that age-related changes in this protein more closely reflect physical activity status than ageing per se. This finding reinforces the need to control for physical activity levels when investigating the natural process of ageing. Taken together, our data confirm and extend knowledge regarding age- and activity-related phenotypes. In addition, the MRM transitions described here provide a methodological platform that can be fine-tuned to suite multiple research needs and thus advance myofibrillar phenotyping.