153 research outputs found

    Consent and privacy in telemedicine.

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    The electronic broadcast of a medical interview, or a video tele-consultation (VTC), challenges many of our traditional concepts of privacy and confidentiality. The nature of a doctor-patient relationship changes dramatically when the open airwaves carry the personal histories, images, and concerns of a patient. Discussions of telemedicine often allude to inherent ethical concerns yet there are no established guidelines for the ethical conduct of a VTC

    Vortical and Wave Modes in 3D Rotating Stratified Flows: Random Large Scale Forcing

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    Utilizing an eigenfunction decomposition, we study the growth and spectra of energy in the vortical and wave modes of a 3D rotating stratified fluid as a function of ϵ=f/N\epsilon = f/N. Working in regimes characterized by moderate Burger numbers, i.e. Bu=1/ϵ2<1Bu = 1/\epsilon^2 < 1 or Bu1Bu \ge 1, our results indicate profound change in the character of vortical and wave mode interactions with respect to Bu=1Bu = 1. As with the reference state of ϵ=1\epsilon=1, for ϵ<1\epsilon < 1 the wave mode energy saturates quite quickly and the ensuing forward cascade continues to act as an efficient means of dissipating ageostrophic energy. Further, these saturated spectra steepen as ϵ\epsilon decreases: we see a shift from k1k^{-1} to k5/3k^{-5/3} scaling for kf<k<kdk_f < k < k_d (where kfk_f and kdk_d are the forcing and dissipation scales, respectively). On the other hand, when ϵ>1\epsilon > 1 the wave mode energy never saturates and comes to dominate the total energy in the system. In fact, in a sense the wave modes behave in an asymmetric manner about ϵ=1\epsilon = 1. With regard to the vortical modes, for ϵ1\epsilon \le 1, the signatures of 3D quasigeostrophy are clearly evident. Specifically, we see a k3k^{-3} scaling for kf<k<kdk_f < k < k_d and, in accord with an inverse transfer of energy, the vortical mode energy never saturates but rather increases for all k<kfk < k_f. In contrast, for ϵ>1\epsilon > 1 and increasing, the vortical modes contain a progressively smaller fraction of the total energy indicating that the 3D quasigeostrophic subsystem plays an energetically smaller role in the overall dynamics.Comment: 18 pages, 6 figs. (abbreviated abstract

    Recent Developments in Understanding Two-dimensional Turbulence and the Nastrom-Gage Spectrum

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    Two-dimensional turbulence appears to be a more formidable problem than three-dimensional turbulence despite the numerical advantage of working with one less dimension. In the present paper we review recent numerical investigations of the phenomenology of two-dimensional turbulence as well as recent theoretical breakthroughs by various leading researchers. We also review efforts to reconcile the observed energy spectrum of the atmosphere (the spectrum) with the predictions of two-dimensional turbulence and quasi-geostrophic turbulence.Comment: Invited review; accepted by J. Low Temp. Phys.; Proceedings for Warwick Turbulence Symposium Workshop on Universal features in turbulence: from quantum to cosmological scales, 200

    Electronic neutron personal dosemeters: their performance in mixed radiation fields in nuclear power plants

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    This work describes spectral distributions of neutrons obtained as function of energy and direction at four workplace fields at the Krümmel reactor in Germany. Values of personal dose equivalent Hp(10) and effective dose E are determined for different directions of a person's orientation in these fields and readings of personal neutron dosemeters—especially electronic dosemeters—are discussed with respect to Hp(10) and

    Neutron area survey instrument measurements in the EVIDOS project

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    Neutron survey instruments have been exposed at all the measurement locations used in the EVIDOS project. These results have an important impact in the interpretation of the results from the project, since operationally the survey instrument will be used for an initial assessment of and routine monitoring of the ambient dose equivalent dose rate. Additionally, since the response of these instruments is in some cases very well characterised, their systematic deviations from the reference quantities provide an important verification of the determination of those quantitie

    Politicizing food security governance through participation: opportunities and opposition

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    Since the 2007/08 food price crisis there has been a proliferation of multi-stakeholder processes (MSPs) devoted to bringing diverse perspectives together to inform and improve food security policy. While much of the literature highlights the positive contributions to be gained from an opening-up of traditionally state-led processes, there is a strong critique emerging to show that, in many instances, MSPs have de-politicizing effects. In this paper, we scrutinize MSPs in relation to de-politicization. We argue that re-building sustainable and just food systems requires alternative visions that can best be made visible through politicized policy processes. Focusing on three key conditions of politicization, we examine the UN Committee on World Food Security as a MSP where we see a process of politicization playing out through the endorsement of the ‘most-affected’ principle, which is in turn being actively contested by traditionally powerful actors. We conclude that there is a need to implement and reinforce mechanisms that deliberately politicize participation in MSPs, notably by clearly distinguishing between states and other stakeholders, as well as between categories of non-state actors.</p

    Landscape history, time lags and drivers of change : urban natural grassland remnants in Potchefstroom, South Africa

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    The history of the landscape directly affects biotic assemblages, resulting in time lags in species response to disturbances. In highly fragmented environments, this phenomenon often causes extinction debts. However, few studies have been carried out in urban settings. To determine if there are time lags in the response of temperate natural grasslands to urbanization. Does it differ for indigenous species and for species indicative of disturbance and between woody and open grasslands? Do these time lags change over time? What are the potential landscape factors driving these changes? What are the corresponding vegetation changes? In 1995 and 2012 vegetation sampling was carried out in 43 urban grassland sites. We calculated six urbanization and landscape measures in a 500 m buffer area surrounding each site for 1938, 1961, 1970, 1994, 1999, 2006, and 2010. We used generalized linear models and model selection to determine which time period best predicted the contemporary species richness patterns. Woody grasslands showed time lags of 20-40 years. Contemporary open grassland communities were, generally, associated with more contemporary landscapes. Altitude and road network density of natural areas were the most frequent predictors of species richness. The importance of the predictors changed between the different models. Species richness, specifically, indigenous herbaceous species, declined from 1995 to 2012. The history of urbanization affects contemporary urban vegetation assemblages. This indicates potential extinction debts, which have important consequences for biodiversity conservation planning and sustainable future scenarios.Peer reviewe
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