807 research outputs found

    Valuing initial teacher education at Master's level

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    The future of Master’s-level work in initial teacher education (ITE) in England seems uncertain. Whilst the coalition government has expressed support for Master’s-level work, its recent White Paper focuses on teaching skills as the dominant form of professional development. This training discourse is in tension with the view of professional learning advocated by ITE courses that offer Master’s credits. Following a survey of the changing perceptions of Master’s-level study during a Post Graduate Certificate in Education course by student teachers in four subject groups, this paper highlights how the process of professional learning can have the most impact on how they value studying at a higher level during their early professional development

    More Discriminants with the Brezing-Weng Method

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    The Brezing-Weng method is a general framework to generate families of pairing-friendly elliptic curves. Here, we introduce an improvement which can be used to generate more curves with larger discriminants. Apart from the number of curves this yields, it provides an easy way to avoid endomorphism rings with small class number

    Serum S-adenosylmethionine, but not methionine, increases in response to overfeeding in humans

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    Background: Plasma concentration of the methyl donor S-adenosylmethionine (SAM) is linearly associated with body mass index (BMI) and fat mass. As SAM is a high-energy compound and a sensor of cellular nutrient status, we hypothesized that SAM would increase with overfeeding. Methods: Forty normal to overweight men and women were overfed by 1250 kcal per day for 28 days. Results: Serum SAM increased from 106 to 130 nmol/l (P=0.006). In stratified analysis, only those with weight gain above the median (high-weight gainers; average weight gain 3.9±0.3 kg) had increased SAM (+42%, P=0.001), whereas low-weight gainers (weight gain 1.5±0.2 kg) did not (Pinteraction=0.018). Overfeeding did not alter serum concentrations of the SAM precursor, methionine or the products, S-adenosyl-homocysteine and homocysteine. The SAM/SAH (S-adenosylhomocysteine) ratio was unchanged in the total population, but increased in high-weight gainers (+52%, P=0.006, Pinteraction =0.005). Change in SAM correlated positively with change in weight (r=0.33, P=0.041) and fat mass (r=0.44, P=0.009), but not with change in protein intake or plasma methionine, glucose, insulin or low-density lipoprotein (LDL)-cholesterol. Conclusion: Overfeeding raised serum SAM in proportion to the fat mass gained. The increase in SAM may help stabilize methionine levels, and denotes a responsiveness of SAM to nutrient state in humans. The role of SAM in human energy metabolism deserves further attention.A K Elshorbagy, F Jernerén, D Samocha-Bonet, H Refsum and L K Heilbron

    Wigs, disguises and child's play : solidarity in teacher education

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    It is generally acknowledged that much contemporary education takes place within a dominant audit culture, in which accountability becomes a powerful driver of educational practices. In this culture both pupils and teachers risk being configured as a means to an assessment and target-driven end: pupils are schooled within a particular paradigm of education. The article discusses some ethical issues raised by such schooling, particularly the tensions arising for teachers, and by implication, teacher educators who prepare and support teachers for work in situations where vocational aims and beliefs may be in in conflict with instrumentalist aims. The article offers De Certeau’s concept of ‘la perruque’ to suggest an opening to playful engagement for human ends in education, as a way of contending with and managing the tensions generated. I use the concept to recover a concept of solidarity for teacher educators and teachers to enable ethical teaching in difficult times

    Loss of mglur5 in d1 receptor-expressing neurons improves stress coping

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    The metabotropic glutamate receptor type 5 (mGluR5) has been proposed to play a crucial role in the selection and regulation of cognitive, affective, and emotional behaviors. However, the mechanisms by which these receptors mediate these effects remain largely unexplored. Here, we studied the role of mGluR5 located in D1 receptor-expressing (D1) neurons in the manifestation of different behavioral expressions. Mice with conditional knockout (cKO) of mGluR5 in D1 neurons (mGluR5D1 cKO) and littermate controls displayed similar phenotypical profiles in relation to memory expression, anxiety, and social behaviors. However, mGluR5D1 cKO mice presented different coping mechanisms in response to acute escapable or inescapable stress. mGluR5D1 cKO mice adopted an enhanced active stress coping strategy upon exposure to escapable stress in the two-way active avoidance (TWA) task and a greater passive strategy upon exposure to inescapable stress in the forced swim test (FST). In summary, this work provides evidence for a functional integration of the dopaminergic and glutamatergic system to mediate control over internal states upon stress exposure and directly implicates D1 neurons and mGluR5 as crucial mediators of behavioral stress responses

    Dietary enrichment with fish oil prevents high fat-induced metabolic dysfunction in skeletal muscle in mice

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    High saturated fat (HF-S) diets increase intramyocellular lipid, an effect ameliorated by omega-3 fatty acids in vitro and in vivo, though little is known about sex- and muscle fiber type-specific effects. We compared effects of standard chow, HF-S, and 7.5% HF-S replaced with fish oil (HF-FO) diets on the metabolic profile and lipid metabolism gene and protein content in red (soleus) and white (extensor digitorum longus) muscles of male and female C57BL/6 mice (n = 9-12/group). Weight gain was similar in HF-S- and HF-FO-fed groups. HF-S feeding increased mesenteric fat mass and lipid marker, Oil Red O, in red and mixed muscle; HF-FO increased interscapular brown fat mass. Compared to chow, HF-S and HF-FO increased expression of genes regulating triacylglycerol synthesis and fatty acid transport, HF-S suppressed genes and proteins regulating fatty acid oxidation, whereas HF-FO increased oxidative genes, proteins and enzymes and lipolytic gene content, whilst suppressing lipogenic genes. In comparison to HF-S, HF-FO further increased fat transporters, markers of fatty acid oxidation and mitochondrial content, and reduced lipogenic genes. No diet-by-sex interactions were observed. Neither diet influenced fiber type composition. However, some interactions between muscle type and diet were observed. HF-S induced changes in triacylglycerol synthesis and lipogenic genes in red, but not white, muscle, and mitochondrial biogenesis and oxidative genes were suppressed by HF-S and increased by HF-FO in red muscle only. In conclusion, HF-S feeding promotes lipid storage in red muscle, an effect abrogated by the fish oil, which increases mediators of lipolysis, oxidation and thermogenesis while inhibiting lipogenic genes. Greater storage and synthesis, and lower oxidative genes in red, but not white, muscle likely contribute to lipid accretion encountered in red muscle. Despite several gender-dimorphic genes, both sexes exhibited a similar HF-S-induced metabolic and gene expression profile; likewise fish oil was similarly protective in both sexes.Lisa K. Philp, Leonie K. Heilbronn, Alena Janovska, Gary A. Witter

    Double differential neutron yields from thick targets used in space applications

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    In March 2016, secondary neutron production from thick-target shielding experiments were conducted at the National Aeronautics and Space Administration’s (NASA) Space Radiation Laboratory at Brookhaven National Laboratory. Ion beams of proton, helium, and iron projectiles were aimed at aluminum targets with areal densities of 20, 40, and 60 g/cm2. The ion beams were extracted at energies of 400 and 800 AMeV and neutron yields were measured with liquid scintillators at 10°, 30°, 45°, 60°, 80°, and 135° off the beam axis. A second 60 g/cm2 aluminum target was placed 3.5 m downstream from the middle of front target to study backscattered neutrons. Double differential thick-target neutron yields for various combinations of projectile, projectile energy, target material, target thickness, and detector location were produced using the time-of-flight technique. These measurements will help NASA perform uncertainty analyses on their transport codes and contribute to shielding design studies for future space applications

    Use of ultra-low dose computed tomography versus abdominal plain film for assessment of stone-free rates after shock-wave lithotripsy: implications on emergency room visits, surgical procedures, and cost-effectiveness

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    The aims of this investigation were: (1) to compare residual stone-fragment (RSF) detection rates of ultra-low dose computed tomography (ULD-CT) and abdominal plain film (KUB) in urolithiasis patients undergoing shock-wave lithotripsy (SWL), and (2) to evaluate the downstream sequelae of utilizing these two disparate imaging pathways of differing diagnostic fidelity. A retrospective chart-review of patients undergoing SWL at two high-volume surgical centers was undertaken (2013-2016). RSF diagnostic rates of ULD-CT and KUB were assessed, and the impact of imaging modality used on subsequent emergency room (ER) visits, unplanned procedures, and cost-effectiveness was investigated. Adjusted analyses examined association between imaging modality used and outcomes, and Markov decision-tree analysis was performed to identify a cost advantageous scenario for ULD-CT over KUB. Of 417 patients studied, 57 (13.7%) underwent ULD-CT while the remaining 360 underwent KUB. The RSF rates were 36.8% and 22.8% in the ULD-CT and KUB groups, respectively (p = 0.019). A 5.6% and 18% of the patients deemed stone-free on ULD-CT and KUB, respectively, returned to the ER (p = 0.040). Similarly, 2.8% and 15.1% needed an unplanned surgery (p = 0.027). These findings were confirmed on multivariable analyses, Odds ratios CT-ULD versus KUB: 0.19 and 0.10, respectively, p \u3c 0.05. With regards to cost-effectiveness, at low ULD-CT charges, the ULD-CT follow-up pathway was economically more favorable, but with increasing ULD-CT charges, the KUB follow-up pathway superseded. ULD-CT seems to provide a more \u27true\u27 estimate of stone-free status, and in consequence mitigates unwanted emergency and operating room visits by reducing untimely stent removals and false patient reassurances. Further, at low ULD-CT costs, it may also be economically more favorable

    Fragmentation of 14-N, 16-O, 20-Ne, and 24-Mg Nuclei at 290 to 1000 MeV/nucleon

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    We report fragmentation cross sections measured at 0 deg for beams of 14-N, 16-O, 20-Ne, and 24-Mg ions, at energies ranging from 290 MeV/nucleon to 1000 MeV/nucleon. Beams were incident on targets of C, CH2, Al, Cu, Sn, and Pb, with the C and CH2 target data used to obtain hydrogen-target cross sections. Using methods established in earlier work, cross sections obtained with both large-acceptance and small-acceptance detectors are extracted from the data and when necessary corrected for acceptance effects. The large-acceptance data yield cross sections for fragments with charges approximately half of the beam charge and above, with minimal corrections. Cross sections for lighter fragments are obtained from small-acceptance spectra, with more significant, model-dependent corrections that account for the fragment angular distributions. Results for both charge-changing and fragment production cross sections are compared to the predictions of the Los Alamos version of the Quark Gluon String Model (LAQGSM) as well as the NUCFRG2 and PHITS models. For all beams and targets, cross sections for fragments as light as He are compared to the models. Estimates of multiplicity-weighted helium production cross sections are obtained from the data and compared to PHITS and LAQGSM predictions. Summary statistics show that the level of agreement between data and predictions is slightly better for PHITS than for either NUCFRG2 or LAQGSM.Comment: 26 pages, 15 figures, 13 tables, to be published in Phys. Rev.
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