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11.
Radiation induced brain damage is associated with impairment of mitochondrial functions, variations in the level of neurotransmitters, and oxidative stress. Mitochondrial function is closely linked to the level of neurotransmitters since the precursors are supplied by the Kreb’s cycle intermediates. The objective of this study was to evaluate the influence of pantothenic acid, an essential component in the synthesis of Coenzyme A (CoA), on the activity of the Krebs cycle enzymes, isocitrate dehydrogenase (IDH), α-ketoglutarate dehydrogenase (α-KGDH), and succinate dehydrogenase (SDH); the level of aspartic, glutamic and GABA; the activity of transaminases, and oxidative stress, in the cerebrum of γ-irradiated rats. Pantothenic acid (26 mg/Kg) was orally administered to the rats, 2 h after irradiation and during the following 5 days. Animals were sacrificed the 7th day post-irradiation. The exposure of male albino rats to γ-rays (5 Gy) has triggered oxidative stress notified by a significant elevation in the level of malondialdehyde (MDA), an end product of lipid peroxidation, associated to a significant decrease in the content of phospholipids, and the antioxidant compound glutathione (GSH). The activity of IDH, α-KGDH, and SDH, has significantly decreased, while the level of aspartic, glutamic and GABA has significantly increased. In parallel to these changes, the activity of alanine and aspartate transaminase has significantly increased, compared to their values in the control rats. Pantothenic acid treatment, has significantly attenuated oxidative stress; enhanced the activity of IDH, α-KGDH, and SDH; minimized the increase in the level of amino acids and the activity of transaminases, compared to their values in the cerebrum of irradiated rats. In conclusion, pantothenic acid could improve the level of neurotransmitters amino acids, which depends on the enzymatic activities of Krebs cycle and linked to oxidative stress.  相似文献   
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We developed an empirical Bayes (EB) enhancement to Mantel-Haenszel (MH) DIF analysis in which we assume that the MH statistics are normally distributed and that the prior distribution of underlying DIF parameters is also normal. We use the posterior distribution of DIF parameters to make inferences about the item's true DIF status and the posterior predictive distribution to predict the item's future observed status. DIF status is expressed in terms of the probabilities associated with each of the five DIF levels defined by the ETS classification system: C–, B–, A, B+, and C+. The EB methods yield more stable DIF estimates than do conventional methods, especially in small samples, which is advantageous in computer-adaptive testing. The EB approach may also convey information about DIF stability in a more useful way by representing the state of knowledge about an item's DIF status as probabilistic.  相似文献   
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There are few data in the published literature on sweat loss and drinking behaviour in athletes training in a cool environment. Sweat loss and fluid intake were measured in 17 first-team members of an elite soccer team training for 90 min in a cool (5°C, 81% relative humidity) environment. Sweat loss was assessed from the change in body mass after correction for the volume of fluid consumed. Sweat electrolyte content was measured from absorbent patches applied at four skin sites. Mean (?± s) sweat loss during training was 1.69?±?0.45 l (range 1.06?-?2.65 l). Mean fluid intake during training was 423?±?215 ml (44?-?951 ml). There was no apparent relationship between the amount of sweat lost and the volume of fluid consumed during training (r 2 = 0.013, P = 0.665). Mean sweat sodium concentration was 42.5?±?13.0 mmol?·?l?1 and mean sweat potassium concentration was 4.2?±?1.0 mmol?·?l?1. Total salt (NaCl) loss during training was 4.3?±?1.8 g. The sweat loss data are similar to those recorded in elite players undergoing a similar training session in warm environments, but the volume of fluid ingested is less.  相似文献   
14.
The Non-Equivalent-groups Anchor Test (NEAT) design has been in wide use since at least the early 1940s. It involves two populations of test takers, P and Q, and makes use of an anchor test to link them. Two linking methods used for NEAT designs are those (a) based on chain equating and (b) that use the anchor test to post-stratify the distributions of the two operational test scores to a common population (i.e., Tucker equating and frequency estimation). We show that, under different sets of assumptions, both methods are observed score equating methods and we give conditions under which the methods give identical results. In addition, we develop analogues of the Dorans and Holland (2000) RMSD measures of population invariance of equating methods for the NEAT design for both chain and post-stratification equating methods.  相似文献   
15.
The EU’s lifelong learning policy has emerged as an overarching educational reform policy intended to address a wide range of issues, including education, employment and competitiveness. The question has been raised as to whether the resulting policy is merely a catch‐all concept that can be applied to any needs or whether it is underpinned by a comprehensive concept and strategy. This article advances the notion of institutional learning as the selective adoption by organisations of characteristics or policies from other organisations, as opposed to the wholesale homogenisation suggested by institutional isomorphism. Based on our periodisation of international lifelong learning policy, this article argues that a complete historical analysis of the discourse on lifelong learning, coupled with an analysis of the European Commission’s institutional learning from others will give a more appropriate picture of what contributed to the current conceptualisation of lifelong learning.  相似文献   
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Drawing on cultural-ecological and person-environment fit perspectives, this study examined links among Mexican-American adolescents' time with peers and parents, parents' cultural orientations, and adolescents' psychosocial adjustment and cultural orientations. Participants were 492 Mexican-American adolescents (Ms=15.7 and 12.8 years for older siblings and younger siblings) and their parents in 246 families. Family members described their family relationships, cultural orientations, and psychosocial functioning in home interviews, and time-use data were collected during a series of nightly phone calls. Mexican-American adolescents spent the majority of their peer time with Mexican youth. Some support was found for the hypothesis that the mismatch between parents' cultural orientations and adolescents' peer involvement is linked to adolescents' psychosocial functioning.  相似文献   
19.
The mountains of data amassed by the various audience research services are rarely mined for the underlying factors of audience behavior. Published as part of the rating service reports is a vast amount of qualitative information that can be used to build a coherent picture of some of the many audiences to broadcast programs. (See “Qualitative Information Concerning Audiences of Network Television Programs” by Harrison B. Sommers, Journal op Broadcasting, Vol. V, No. 3, pp.147–160, Spring 1961.) The present study offers some predictable and some unpredictable findings from such published data on television program types and audience composition.  相似文献   
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Within the framework of large regional and national networks, local libraries can benefit by working together. We report the establishment of an online health sciences library network to share resources and technical support in the greater St. Louis area. BACS/PHILNET has evolved beyond a local automated interlibrary loan network to pilot off-site integrated library and information management systems in hospitals.  相似文献   
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