Growth and properties of GaSbBi alloys

Molecular-beam epitaxy has been used to grow GaSb 1− x Bi x alloys with x up to 0.05. The Bi content, lattice expansion, and film thickness were determined by Rutherford backscattering and x-ray diffraction, which also indicate high crystallinity and that >98% of the Bi atoms are substitutional. The observed Bi-induced lattice dilation is consistent with density functional theory calculations. Optical absorption measurements and valence band anticrossing modeling indicate that the room temperature band gap varies from 720 meV for GaSb to 540 meV for GaSb 0.95Bi0.05, corresponding to a reduction of 36 meV/%Bi or 210 meV per 0.01 Å change in lattice constant

A negative feedback loop mediated by the Bcl6-cullin 3 complex limits Tfh cell differentiation

Induction of Bcl6 (B cell lymphoma 6) is essential for T follicular helper (Tfh) cell differentiation of antigen-stimulated CD4(+) T cells. Intriguingly, we found that Bcl6 was also highly and transiently expressed during the CD4(+)CD8(+) (double positive [DP]) stage of T cell development, in association with the E3 ligase cullin 3 (Cul3), a novel binding partner of Bcl6 which ubiquitinates histone proteins. DP stage-specific deletion of the E3 ligase Cul3, or of Bcl6, induced the derepression of the Bcl6 target genes Batf (basic leucine zipper transcription factor, ATF-like) and Bcl6, in part through epigenetic modifications of CD4(+) single-positive thymocytes. Although they maintained an apparently normal phenotype after emigration, they expressed increased amounts of Batf and Bcl6 at basal state and produced explosive and prolonged Tfh responses upon subsequent antigen encounter. Ablation of Cul3 in mature CD4(+) splenocytes also resulted in dramatically exaggerated Tfh responses. Thus, although previous studies have emphasized the essential role of Bcl6 in inducing Tfh responses, our findings reveal that Bcl6-Cul3 complexes also provide essential negative feedback regulation during both thymocyte development and T cell activation to restrain excessive Tfh responses

Special and inclusive education in the Republic of Ireland: reviewing the literature from 2000 to 2009

Provision for pupils with special educational needs in Ireland has undergone considerable change and review in the first decade of the twenty first century. In response to international demands for a more equitable education system which recognises diversity and considers how schools might address the needs of pupils who have been previously marginalised, Irish legislation has focused upon the development of inclusive schooling. Researchers during this period have endeavoured to understand how responses to the demand for greater inclusion have impacted upon the perceived need for change. This paper reviews the research literature for this period and identifies four key themes under which research has been conducted. The literature pertaining to these themes is explored and a possible agenda for future researchers identifie

Groundwater depletion embedded in international food trade

Recent hydrological modelling1 and Earth observations2,3 have located and quantified alarming rates of groundwater depletion worldwide. This depletion is primarily due to water withdrawals for irrigation1,2,4, but its connection with the main driver of irrigation, global food consumption, has not yet been explored. Here we show that approximately eleven per cent of non-renewable groundwater use for irrigation is embedded in international food trade, of which two-thirds are exported by Pakistan, the USA and India alone. Our quantification of groundwater depletion embedded in the world’s food trade is based on a combination of global, cropspecific estimates of non-renewable groundwater abstraction and international food trade data. A vast majority of the world’s population lives in countries sourcing nearly all their staple crop imports from partners who deplete groundwater to produce these crops, highlighting risks for global food and water security. Some countries, such as the USA, Mexico, Iran and China, are particularly exposed to these risks because they both produce and import food irrigated from rapidly depleting aquifers. Our results could help to improve the sustainability of global food production and groundwater resource management by identifying priority regions and agricultural products at risk as well as the end consumers of these products

Effect of Polyethylene Glycol 3350 on the Handling Properties of Low Salt Wheat Dough Formulations

The effect of polyethylene glycol (PEG) 3350 addition (3%, flour wt. basis) on the properties of dough made from two Canadian Western Red Spring wheat cultivars (Triticum aestivum L. ‘Harvest’ and ‘Pembina’) differing in dough mixing requirements and dough-handling properties was investigated in a low salt dough formulation (1% NaCl, flour wt. basis). PEG was added for experimental purposes to alter water mobility to better understand underlining mechanisms, however would not be used in real bread formulations. For cultivar Harvest, but not Pembina, dough stickiness was reduced by the addition of PEG. Dough freezable water content decreased with the addition of PEG for both cultivars. Rheological measurements showed that PEG increased dough stiffness as measured by the complex modulus |G*|. Creep measurements indicated that the relative elastic component (Jel) increased whereas maximum deformation (Jmax) decreased with the addition of PEG for cultivar Harvest only. Dough made with a weaker cultivar (Harvest) with the addition of PEG performed similarly to dough made with a stronger cultivar (Pembina) without PEG. Results indicate that in a low sodium environment, availability of water is critically important for controlling a number of properties that relate closely to dough machinability, especially in a weaker wheat cultivar

Measurement of spin correlation in ttbar production using a matrix element approach

correlation, assuming that the spin of the top quark is either correlated with the spin of the anti-top quark as predicted by the standard model or is uncorrelated. For the first time we use a matrix-element-based approach to study ttbar spin correlation. We use {ttbar -> W+bW-bbar ->l+nubl-nub} final states produced in ppbar collisions at a center of mass energy sqrt(s)=1.96 TeV, where l denotes an electron or a muon. The data correspond to an integrated luminosity of 5.4 fb-1 and were collected with the dzero detector at the Fermilab Tevatron collider. The result agrees with the standard model prediction. We exclude the hypothesis that the spins of the ttbar are uncorrelated at the 97.7% C.L.Comment: 7 pages, 3 figures, submitted to Phys. Rev. Let

Regulation of Small RNA Accumulation in the Maize Shoot Apex

MicroRNAs (miRNAs) and trans-acting siRNAs (ta-siRNAs) are essential to the establishment of adaxial–abaxial (dorsoventral) leaf polarity. Tas3-derived ta-siRNAs define the adaxial side of the leaf by restricting the expression domain of miRNA miR166, which in turn demarcates the abaxial side of leaves by restricting the expression of adaxial determinants. To investigate the regulatory mechanisms that allow for the precise spatiotemporal accumulation of these polarizing small RNAs, we used laser-microdissection coupled to RT-PCR to determine the expression profiles of their precursor transcripts within the maize shoot apex. Our data reveal that the pattern of mature miR166 accumulation results, in part, from intricate transcriptional regulation of its precursor loci and that only a subset of mir166 family members contribute to the establishment of leaf polarity. We show that miR390, an upstream determinant in leaf polarity whose activity triggers tas3 ta-siRNA biogenesis, accumulates adaxially in leaves. The polar expression of miR390 is established and maintained independent of the ta-siRNA pathway. The comparison of small RNA localization data with the expression profiles of precursor transcripts suggests that miR166 and miR390 accumulation is also regulated at the level of biogenesis and/or stability. Furthermore, mir390 precursors accumulate exclusively within the epidermal layer of the incipient leaf, whereas mature miR390 accumulates in sub-epidermal layers as well. Regulation of miR390 biogenesis, stability, or even discrete trafficking of miR390 from the epidermis to underlying cell layers provide possible mechanisms that define the extent of miR390 accumulation within the incipient leaf, which patterns this small field of cells into adaxial and abaxial domains via the production of tas3-derived ta-siRNAs

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

International society of sports nutrition position stand: coffee and sports performance

Based on review and critical analysis of the literature regarding the contents and physiological effects of coffee related to physical and cognitive performance conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society: (1) Coffee is a complex matrix of hundreds of compounds. These are consumed with broad variability based upon serving size, bean type (e.g. common Arabica vs. Robusta), and brew method (water temperature, roasting method, grind size, time, and equipment). (2) Coffee’s constituents, including but not limited to caffeine, have neuromuscular, antioxidant, endocrine, cognitive, and metabolic (e.g. glucose disposal and vasodilation) effects that impact exercise performance and recovery. (3) Coffee’s physiologic effects are influenced by dose, timing, habituation to a small degree (to coffee or caffeine), nutrigenetics, and potentially by gut microbiota differences, sex, and training status. (4) Coffee and/or its components improve performance across a temporal range of activities from reaction time, through brief power exercises, and into the aerobic time frame in most but not all studies. These broad and varied effects have been demonstrated in men (mostly) and in women, with effects that can differ from caffeine ingestion, per se. More research is needed. (5) Optimal dosing and timing are approximately two to four cups (approximately 473–946 ml or 16–32 oz.) of typical hot-brewed or reconstituted instant coffee (depending on individual sensitivity and body size), providing a caffeine equivalent of 3–6 mg/kg (among other components such as chlorogenic acids at approximately 100–400 mg per cup) 60 min prior to exercise. (6) Coffee has a history of controversy regarding side effects but is generally considered safe and beneficial for healthy, exercising individuals in the dose range above. (7) Coffee can serve as a vehicle for other dietary supplements, and it can interact with nutrients in other foods. (8) A dearth of literature exists examining coffee-specific ergogenic and recovery effects, as well as variability in the operational definition of “coffee,” making conclusions more challenging than when examining caffeine in its many other forms of delivery (capsules, energy drinks, “pre-workout” powders, gum, etc.)