380 research outputs found

    Radiation-induced oscillatory magnetoresistance as a sensitive probe of the zero-field spin splitting in high mobility GaAs/AlGaAs devices

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    We suggest an approach for characterizing the zero-field spin splitting of high mobility two-dimensional electron systems, when beats are not readily observable in the Shubnikov-de Haas effect. The zero-field spin splitting and the effective magnetic field seen in the reference frame of the electron is evaluated from a quantitative study of beats observed in radiation-induced magnetoresistance oscillations.Comment: 4 pages, 4 color figure

    Environmental pressure from the 2014–15 eruption of Bárðarbunga volcano, Iceland

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    The effusive six months long 2014-2015 Bárðarbunga eruption (31 August-27 February) was the largest in Iceland for more than 200 years, producing 1.6 ± 0.3 km3 of lava. The total SO2 emission was 11 ± 5 Mt, more than the amount emitted from Europe in 2011. The ground level concentration of SO2 exceeded the 350 μg m−3 hourly average health limit over much of Iceland for days to weeks. Anomalously high SO2 concentrations were also measured at several locations in Europe in September. The lowest pH of fresh snowmelt at the eruption site was 3.3, and 3.2 in precipitation 105 km away from the source. Elevated dissolved H2SO4, HCl, HF, and metal concentrations were measured in snow and precipitation. Environmental pressures from the eruption and impacts on populated areas were reduced by its remoteness, timing, and the weather. The anticipated primary environmental pressure is on the surface waters, soils, and vegetation of Iceland

    Role of adenylate cyclase 9 in the pharmacogenomic response to dalcetrapib clinical paradigm and molecular mechanisms in precision cardiovascular medicine

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    Following the neutral results of the dal-OUTCOMES trial, a genome-wide study identified the rs1967309 variant in the adenylate cyclase type 9 (ADCY9) gene on chromosome 16 as being associated with the risk of future cardiovascular events only in subjects taking dalcetrapib, a CETP (cholesterol ester transfer protein) modulator. Homozygotes for the minor A allele (AA) were protected from recurrent cardiovascular events when treated with dalcetrapib, while homozygotes for the major G allele (GG) had increased risk. Here, we present the current state of knowledge regarding the impact of rs1967309 in ADCY9 on clinical observations and biomarkers in dalcetrapib trials and the effects of mouse ADCY9 gene inactivation on cardiovascular physiology. Finally, we present our current model of the interaction between dalcetrapib and ADCY9 gene variants in the arterial wall macrophage, based on the intracellular role of CETP in the transfer of complex lipids from endoplasmic reticulum membranes to lipid droplets. Briefly, the concept is that dalcetrapib would inhibit CETP-mediated transfer of cholesteryl esters, resulting in a progressive inhibition of cholesteryl ester synthesis and free cholesterol accumulation in the endoplasmic reticulum. Reduced ADCY9 activity, by paradoxically leading to higher cyclic AMP levels and in turn increased cellular cholesterol efflux, could impart cardiovascular protection in rs1967309 AA patients. The ongoing dal-GenE trial recruited 6145 patients with the protective AA genotype and will provide a definitive answer to whether dalcetrapib will be protective in this population.Cardiolog

    Innovation and HRM : absences and politics

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    This article analyses the role of HRM practices in the implementation of an innovative cross-functional approach to new product development (concurrent engineering, CE) in Eurotech Industries. Contrary to CE methodology stipulations, and despite supportive conditions, HRM received scant attention in the implementation process. Organizational power and politics were clearly involved in this situation, and this article explores how their play created such HRM &lsquo;absences&rsquo;. The article builds on a four-dimensional view of power in order to provide a deeper understanding of the embedded, interdependent and political nature of HRM practice and innovation.<br /

    The governance of co-operatives and mutual associations: a paradox perspective

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    This paper presents a new theoretical framework for understanding the governance of co-operative and mutual organisations. The theoretical literature on the governance of co-operatives is relatively undeveloped in comparison with that on corporate governance. The paper briefly reviews some of the main theoretical perspectives on corporate governance and discusses how they can be usefully extended to throw light on the governance of co-operatives and mutuals. However, taken individually these different theories are rather one dimensional, only illuminating a particular aspect of the board's role. This has lead to calls for a new conceptual framework that can help integrate the insights of these different theories. The paper argues that a paradox perspective offers a promising way forward. Contrasting the different theoretical perspectives highlights some of the important paradoxes, ambiguities and tensions that boards face

    Star clusters near and far; tracing star formation across cosmic time

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    © 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00690-x.Star clusters are fundamental units of stellar feedback and unique tracers of their host galactic properties. In this review, we will first focus on their constituents, i.e.\ detailed insight into their stellar populations and their surrounding ionised, warm, neutral, and molecular gas. We, then, move beyond the Local Group to review star cluster populations at various evolutionary stages, and in diverse galactic environmental conditions accessible in the local Universe. At high redshift, where conditions for cluster formation and evolution are more extreme, we are only able to observe the integrated light of a handful of objects that we believe will become globular clusters. We therefore discuss how numerical and analytical methods, informed by the observed properties of cluster populations in the local Universe, are used to develop sophisticated simulations potentially capable of disentangling the genetic map of galaxy formation and assembly that is carried by globular cluster populations.Peer reviewedFinal Accepted Versio
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