3,043 research outputs found

    The addition of whey protein to a carbohydrate–electrolyte drink does not influence post-exercise rehydration

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    The addition of whey protein to a carbohydrate-electrolyte drink has been shown to enhance post-exercise rehydration when a volume below that recommended for full fluid balance restoration is provided. We investigated if this held true when volumes sufficient to restore fluid balance were consumed, and if differences might be explained by changes in plasma albumin content. Sixteen participants lost ~1.9% of their pre- exercise body mass by cycling in the heat and rehydrated with 150% of body mass lost with either a 60 g·L-1 carbohydrate drink (CHO) or a 60 g·L-1 carbohydrate, 20 g·L-1 whey protein isolate drink (CHO-P). Urine and blood samples were collected pre-exercise, post-exercise, post- rehydration and every hour for 4 h post-rehydration. There was no difference between trials for total urine production (CHO 1057±319 mL; CHO-P 970±334 mL; P=0.209), drink retention (CHO 51±12%; CHO-P 55±15%; P=0.195) or net fluid balance (CHO -393±272 mL; CHO-P - 307±331 mL; P=0.284). Plasma albumin content relative to pre-exercise was increased from 2-4 h during CHO-P only. These results demonstrate that the addition of whey protein isolate to a carbohydrate-electrolyte drink neither enhances nor inhibits rehydration. Therefore, where post- exercise protein ingestion might benefit recovery, this can be consumed without effecting rehydration

    Preemption of Local Regulation of Radio Antennas: A Post- Deerfield Policy for the FCC

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    The proliferation of novel radio delivery systems has resulted in the construction of new forms of radio antennas. Many localities have placed restrictions on the size and/or placement of these antennas, significantly hindering or blocking signal reception. Because the FCC has adopted rules that only partially preempt local regulations, municipalities have enacted laws restricting the use of home satellite dishes. A recent challenge to one such regulation resulted in a Second Circuit decision limiting the scope of FCC review of local regulations. The Authors suggest that the FCC need not take extreme measures such as total preemption or national zoning to enforce their policies. Alternatives that recognize the legitimate objectives of municipal zoning regulations and allow the FCC to correct misinterpretation of the Commission\u27s local zoning preemptive regulations are recommended

    Expanding Space: the Root of all Evil?

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    While it remains the staple of virtually all cosmological teaching, the concept of expanding space in explaining the increasing separation of galaxies has recently come under fire as a dangerous idea whose application leads to the development of confusion and the establishment of misconceptions. In this paper, we develop a notion of expanding space that is completely valid as a framework for the description of the evolution of the universe and whose application allows an intuitive understanding of the influence of universal expansion. We also demonstrate how arguments against the concept in general have failed thus far, as they imbue expanding space with physical properties not consistent with the expectations of general relativity.Comment: 8 pages, accepted for publication in PAS

    Geochemistry of vanadium in hyperalkaline environments

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    Hyperalkaline environments associated with leaching of industrial wastes such as steel slags can have a number of deleterious effects on their local environment including rapid carbonate precipitation and mobilisation of potentially toxic trace metals. Steel slag is the primary byproduct of steelmaking and is enriched in trace elements such as Al, Cr and V. V is of particular concern due to its high concentration in steel slag, its potential toxicity and its mobility in high pH leachate as the vanadate oxyanion (VO43-). This study used aerated and air-excluded batch leaching tests, aerated leachate neutralisation tests, field observations, X-ray microanalysis and electron microscopy techniques to investigate the effects of environmental conditions on V mobility, leachate chemistry and secondary phase formation during weathering of steel slags. Scanning electron microscopy/energy- dispersive X-ray spectroscopy (SEM/EDX) identified four principal mineral phases in unweathered slag comprising dicalcium silicate (Ca2SiO4), dicalcium aluminoferrite (Ca2(Al,Fe)2O5), a CaO-rich phase, and a Wüstite-like solid solution ((Fe, Mn, Mg, Ca)O). V was primarily incorporated in the dicalcium aluminoferrite (~1.1 wt%) and dicalcium silicate phases (~0.4 wt%). During leaching, alkalinity was rapidly produced by dissolution of dicalcium silicate and free lime resulting in a high pH (11.5 – 12.5) leachate. Dicalcium silicate dissolution leads to oversaturation with respect to calcium silicate hydrate (Ca-Si-H) phases and their subsequent precipitation. Under aerated conditions, in-gassing of atmospheric CO2 resulted in CaCO3 precipitation which consumed OH- ions and subsequently lowered solution pH to ~8.0. Micro-focus X-ray absorption spectroscopy (µXAS) analysis showed that V was released as V5+ during dicalcium silicate dissolution. V release was significantly higher under aerated conditions than under air-excluded conditions (~850 ppb and 490 ppb respectively in block leaching tests). Aqueous V concentrations were influenced by Ca3(VO4)2 solubility limits which imposed an inverse relationship on Ca and V concentrations. In air-excluded systems, leachate reaches saturation with respect to Ca3(VO4)2 which precipitates thus limiting aqueous V concentrations. Under aerated conditions, precipitation of CaCO3 provided a sink for aqueous Ca. Leachate therefore remained undersaturated with respect to Ca3(VO4)2, allowing higher concentrations of V to accumulate in solution. Leachate neutralisation experiments showed that some V was incorporated into neo-formed CaCO3 at high pH. V removal was enhanced in the presence of goethite (α-FeOOH). Extended X-ray absorption fine structure (EXAFS) analysis showed that vanadate adsorbed to goethite by formation of inner-sphere complexes indicating that Fe (oxy)hydroxides provide an important environmental sink for V in steel slag leachates. This study highlights the importance of leaching environment for V mobility during weathering of steel slags and suggests that prospects for slag reuse and storage may be improved by the formation of a weathered region containing secondary phases including Ca-Si-H and CaCO3. Leachate neutralisation results demonstrate removal mechanisms for aqueous V which will assist with environmental risk assessment and remediation at legacy sites where leachate has been released to the local aquatic environment

    The centennial of the pecking order: current state and future prospects for the study of dominance hierarchies

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    A century ago, foundational work by Thorleif Schjelderup-Ebbe described a ‘pecking order’ in chicken societies, where individuals could be ordered according to their ability to exert their influence over their group-mates. Now known as dominance hierarchies, these structures have been shown to influence a plethora of individual characteristics and outcomes, situating dominance research as a pillar of the study of modern social ecology and evolution. Here, we first review some of the major questions that have been answered about dominance hierarchies in the last 100 years.Next,we introduce the contributions to this theme issue and summarize howthey provide ongoing insight in the epistemology, physiology and neurobiology, hierarchical structure, and dynamics of dominance. These contributions employ the full range of research approaches available to modern biologists. Cross-cutting themes emerging from these contributions include a focus on cognitive underpinnings of dominance, the application of network-analytical approaches, and the utility of experimental rank manipulations for revealing causal relationships. Reflection on the last 100 years of dominance research reveals how Schjelderup- Ebbe’s early ideas and the subsequent research helped drive a shift from an essentialist view of species characteristics to the modern recognition of rich inter-individual variation in social, behavioural and physiological phenotypes. This article is part of the theme issue ‘The centennial of the pecking order: current state and future prospects for the study of dominance hierarchies’
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