625 research outputs found

    Bolus ingestion of whey protein immediately post-exercise does not influence rehydration compared to energy-matched carbohydrate ingestion

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    Whey protein is a commonly ingested nutritional supplement amongst athletes and regular exercisers; however, its role in post-exercise rehydration remains unclear. Eight healthy male and female participants completed two experimental trials involving the ingestion of 35 g of whey protein (WP) or maltodextrin (MD) at the onset of a rehydration period, followed by ingestion of water to a volume equivalent to 150% of the amount of body mass lost during exercise in the heat. The gastric emptying rates of the solutions were measured using 13C breath tests. Recovery was monitored for a further 3 h by the collection of blood and urine samples. The time taken to empty half of the initial solution (T1/2) was different between the trials (WP = 65.5 ± 11.4 min; MD = 56.7 ± 6.3 min; p = 0.05); however, there was no difference in cumulative urine volume throughout the recovery period (WP = 1306 ± 306 mL; MD = 1428 ± 443 mL; p = 0.314). Participants returned to net negative fluid balance 2 h after the recovery period with MD and 3 h with WP. The results of this study suggest that whey protein empties from the stomach at a slower rate than MD; however, this does not seem to exert any positive or negative effects on the maintenance of fluid balance in the post-exercise period

    Dynamics of systems with isotropic competing interactions in an external field: a Langevin approach

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    We study the Langevin dynamics of a ferromagnetic Ginzburg-Landau Hamiltonian with a competing long-range repulsive term in the presence of an external magnetic field. The model is analytically solved within the self consistent Hartree approximation for two different initial conditions: disordered or zero field cooled (ZFC), and fully magnetized or field cooled (FC). To test the predictions of the approximation we develop a suitable numerical scheme to ensure the isotropic nature of the interactions. Both the analytical approach and the numerical simulations of two-dimensional finite systems confirm a simple aging scenario at zero temperature and zero field. At zero temperature a critical field hch_c is found below which the initial conditions are relevant for the long time dynamics of the system. For h<hch < h_c a logarithmic growth of modulated domains is found in the numerical simulations but this behavior is not captured by the analytical approach which predicts a t1/2t^1/2 growth law at T=0T = 0

    Ordering and Fluctuation of Orbital and Lattice Distortion in Perovskite Manganese Oxides

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    Roles of orbital and lattice degrees of freedom in strongly correlated systems are investigated to understand electronic properties of perovskite Mn oxides such as La_{1-x}Sr_{x}MnO_{3}. An extended double-exchange model containing Coulomb interaction, doubly degenerate orbitals and Jahn-Teller coupling is derived under full polarization of spins with two-dimensional anisotropy. Quantum fluctuation effects of Coulomb interaction and orbital degrees of freedom are investigated by using the quantum Monte Carlo method. In undoped states, it is crucial to consider both the Coulomb interaction and the Jahn-Teller coupling in reproducing characteristic hierarchy of energy scales among charge, orbital-lattice and spin degrees of freedom in experiments. Our numerical results quantitatively reproduce the charge gap amplitude as well as the stabilization energy and the amplitude of the cooperative Jahn-Teller distortion in undoped compounds. Upon doping of carriers, in the absence of the Jahn-Teller distortion, critical enhancement of both charge compressibility and orbital correlation length is found with decreasing doping concentration. These are discussed as origins of strong incoherence in charge dynamics. With the Jahn-Teller coupling in the doped region, collapse of the Jahn-Teller distortion and instability to phase separation are obtained and favorably compared with experiments. These provide a possible way to understand the complicated properties of lightly doped manganites.Comment: 22 pages RevTeX including 25 PS figures, submitted to Phys.Rev.B, replaced version; two figures are replaced by Fig.17 with minor changes in the tex

    Extreme Ultra-Violet Spectroscopy of the Lower Solar Atmosphere During Solar Flares

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    The extreme ultraviolet portion of the solar spectrum contains a wealth of diagnostic tools for probing the lower solar atmosphere in response to an injection of energy, particularly during the impulsive phase of solar flares. These include temperature and density sensitive line ratios, Doppler shifted emission lines and nonthermal broadening, abundance measurements, differential emission measure profiles, and continuum temperatures and energetics, among others. In this paper I shall review some of the advances made in recent years using these techniques, focusing primarily on studies that have utilized data from Hinode/EIS and SDO/EVE, while also providing some historical background and a summary of future spectroscopic instrumentation.Comment: 34 pages, 8 figures. Submitted to Solar Physics as part of the Topical Issue on Solar and Stellar Flare

    Can You Hear us Now? Voices from the Margin: Using Indigenous Methodologies in Geographic Research

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    Indigenous methodologies are an alternative way of thinking about research processes. Although these methodologies vary according to the ways in which different Indigenous communities express their own unique knowledge systems, they do have common traits. This article argues that research on Indigenous issues should be carried out in a manner which is respectful and ethically sound from an Indigenous perspective. This naturally challenges Western research paradigms, yet it also affords opportunities to contribute to the body of knowledge about Indigenous peoples. It is further argued that providing a mechanism for Indigenous peoples to participate in and direct these research agendas ensures that their communal needs are met, and that geographers then learn how to build ethical research relationships with them. Indigenous methodologies do not privilege Indigenous researchers because of their Indigeneity, since there are many ‘insider’ views, and these are thus suitable for both Indigenous and non-Indigenous researchers. However, there is a difference between research done within an Indigenous context using Western methodologies and research done using Indig- enous methodologies which integrates Indigenous voices. This paper will discuss those differences while presenting a historical context of research on Indigenous peoples, providing further insights into what Indigenous methodologies entail, and proposing ways in which the academy can create space for this discourse

    Investigation on viscosity and non-isothermal crystallization behavior of P-bearing steelmaking slags with varying TiO2 content

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    The viscous flow and crystallization behavior of CaO-SiO2-MgO-Al2O3-FetO-P2O5-TiO2 steelmaking slags have been investigated over a wide range of temperatures under Ar (High purity, >99.999 pct) atmosphere, and the relationship between viscosity and structure was determined. The results indicated that the viscosity of the slags slightly decreased with increasing TiO2 content. The constructed nonisothermal continuous cooling transformation (CCT) diagrams revealed that the addition of TiO2 lowered the crystallization temperature. This can mainly be ascribed to that addition of TiO2 promotes the formation of [TiO6]-octahedra units and, consequently, the formation of MgFe2O4-Mg2TiO4 solid solution. Moreover, the decreasing viscosity has a significant effect on enhancing the diffusion of ion units, such as Ca2+ and [TiO4]-tetrahedra, from bulk melts to the crystal–melt interface. The crystallization of CaTiO3 and CaSiTiO5 was consequently accelerated, which can improve the phosphorus content in P-enriched phase (n2CaO·SiO2-3CaO·P2O5). Finally, the nonisothermal crystallization kinetics was characterized and the activation energy for the primary crystal growth was derived such that the activation energy increases from −265.93 to −185.41 KJ·mol−1 with the addition of TiO2 content, suggesting that TiO2 lowered the tendency for the slags to crystallize

    Report of the National Heart, Lung, and Blood Institute Working Group on epigenetics and hypertension

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    Hypertension, defined as a condition associated with 65140-mm Hg systolic blood pressure or 6590-mm Hg diastolic blood pressure, affects >1 billion people worldwide,1 and in 2009 it cost the US healthcare system more than 73billion.2Despitetheavailabilityofmanyantihypertensivetherapies,individualresponsesvary,andefficacyremainsaconcern.Currenttreatmentshaveyieldedonlymodestreductionsintheoveralldiseaseriskevenincountrieswheretherapeuticsareavailableandaffordable.Theinitiatingcausesandthepathogenicmechanismsfordiseaseanditscomorbiditiesremainlargelyunknown,andprognosticmarkersforadulthypertensionthatcouldimproveitsdiagnosis,prevention,and,ultimately,itsmanagementarenotyetavailable.Asaresult,482873 billion.2 Despite the availability of many antihypertensive therapies, individual responses vary, and efficacy remains a concern. Current treatments have yielded only modest reductions in the overall disease risk even in countries where therapeutics are available and affordable. The initiating causes and the pathogenic mechanisms for disease and its comorbidities remain largely unknown, and prognostic markers for adult hypertension that could improve its diagnosis, prevention, and, ultimately, its management are not yet available. As a result, 4828% of the US population and a similar proportion of the adult Western European and Canadian populations experience what is known as \u201cessential hypertension,\u201d3 which is a primary component of several complex, multifactorial, multigenic conditions that are commonly associated with high levels of morbidity and mortality from diabetes mellitus, cardiovascular disease, and renal disease. If the current rise in the number of hypertension cases is not abated, total annual global healthcare costs resulting from suboptimal blood pressure for those >30 years of age could amount to 3.6 trillion more over the next 10 years.

    GRB 010222: A burst within a starburst

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    We present millimeter- and submillimeter-wavelength observations and near-infrared K-band imaging toward the bright gamma-ray burst GRB 010222. Over seven different epochs, a constant source was detected with an average flux density of 3.74 ± 0.53 mJy at 350 GHz and 1.05 ± 0.22 mJy at 250 GHz, giving a spectral index α = 3.78 ± 0.25 (where F ∝ vα). We rule out the possibility that this emission originated from the burst or its afterglow, and we conclude that it is due to a dusty, high-redshift starburst galaxy (SMM J14522 + 4301). We argue that the host galaxy of GRB 010222 is the most plausible counterpart of SMM J14522+4301, based in part on the centimeter detection of the host at the expected level. The optical/near-IR properties of the host galaxy of GRB 010222 suggest that it is a blue sub-L* galaxy, similar to other GRB host galaxies. This contrasts with the enormous far-infrared luminosity of this galaxy based on our submillimeter detection (LBol ≈ 4 × 10 12 L⊙). We suggest that this GRB host galaxy has a very high star formation rate, SFR ≈ 600 M⊙ yr -1, most of which is unseen at optical wavelengths

    An Observational Overview of Solar Flares

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    We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities, the article is split into topical sections which deal with different areas of flare phenomena (footpoints and ribbons, coronal sources, relationship to coronal mass ejections) and their interconnections. We also discuss flare soft X-ray spectroscopy and the energetics of the process. The emphasis is to describe the observations from multiple points of view, while bearing in mind the models that link them to each other and to theory. The present theoretical and observational understanding of solar flares is far from complete, so we conclude with a brief discussion of models, and a list of missing but important observations.Comment: This is an article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

    Measurement of prompt hadron production ratios in pppp collisions at s=\sqrt{s} = 0.9 and 7 TeV

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    The charged-particle production ratios pˉ/p\bar{p}/p, K−/K+K^-/K^+, π−/π+\pi^-/\pi^+, (p+pˉ)/(π++π−)(p + \bar{p})/(\pi^+ + \pi^-), (K++K−)/(π++π−)(K^+ + K^-)/(\pi^+ + \pi^-) and (p+pˉ)/(K++K−)(p + \bar{p})/(K^+ + K^-) are measured with the LHCb detector using 0.3nb−10.3 {\rm nb^{-1}} of pppp collisions delivered by the LHC at s=0.9\sqrt{s} = 0.9 TeV and 1.8nb−11.8 {\rm nb^{-1}} at s=7\sqrt{s} = 7 TeV. The measurements are performed as a function of transverse momentum pTp_{\rm T} and pseudorapidity η\eta. The production ratios are compared to the predictions of several Monte Carlo generator settings, none of which are able to describe adequately all observables. The ratio pˉ/p\bar{p}/p is also considered as a function of rapidity loss, Δy≡ybeam−y\Delta y \equiv y_{\rm beam} - y, and is used to constrain models of baryon transport.Comment: Incorrect entries in Table 2 corrected. No consequences for rest of pape
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