344 research outputs found
Panel: Balancing Acts -- Energy Innovation in a Complex Market
A panel discussion is presented between the speakers of the Canada-United States Law Institute Conference namely David Halts, Gitane De Silva, and Chris Zeigler. Topics include impact of energy industry on climate change; enacting climate policy for bringing out environmental justice, and protection; and enactment of U.S. Clean Air Act for addressing the sam
Development and initial validation of the Falls Efficacy Scale-International (FES-I)
Background: there is a need for a measure of fear of falling that assesses both easy and difficult physical activities and social activities and is suitable for use in a range of languages and cultural contexts, permitting direct comparison between studies and populations in different countries and settings. Objective: to develop a modified version of the Falls Efficacy Scale to satisfy this need, and to establish its psychometric properties, reliability, and concurrent validity (i.e. that it demonstrates the expected relationship with age, falls history and falls risk factors). Design: cross-sectional survey. Setting: community sample. Method: 704 people aged between 60 and 95 years completed The Falls Efficacy Scale-International (FES-I) either in postal self-completion format or by structured interview. Results: the FES-I had excellent internal and test-retest reliability (Cronbach's α=0.96, ICC=0.96). Factor analysis suggested a unitary underlying factor, with two dimensions assessing concern about less demanding physical activities mainly in the home, and concern about more demanding physical activities mainly outside the home. The FES-I had slightly better power than the original FES items to discriminate differences in concern about falling between groups differentiated by sex, age, occupation, falls in the past year, and falls risk factors (chronic illness, taking multiple or psychoactive medications, dizziness). Conclusions: the FES-I has close continuity with the best existing measure of fear of falling, excellent psychometric properties, and assesses concerns relating to basic and more demanding activities, both physical and social. Further research is required to confirm cross-cultural and predictive validit
Bilayer Button Graft for Endoscopic Repair of High-Flow Cranial Base Defects
Closure of dural defects in trans-nasal, extended, endoscopic techniques remains a challenge, and published cerebrospinal fluid (CSF) leak rates are higher than rates for trans-cranial approaches. Development of a technique that used a vascularized, nasoseptal flap (NSF) significantly reduced the rate of CSF leak, and several groups have developed ways to buttress the NSF. A closure technique developed at our institution uses a bilayer “button” of fascia lata. The initial series of twenty patients repaired with this method from 2007 to July 1, 2009 were presented, with a CSF leak rate of 10% (Luginbuhl et al 2010)
Coupled land surface/hydrologic/atmospheric models
The topics covered include the following: prototype land cover characteristics data base for the conterminous United States; surface evapotranspiration effects on cumulus convection and implications for mesoscale models; the use of complex treatment of surface hydrology and thermodynamics within a mesoscale model and some related issues; initialization of soil-water content for regional-scale atmospheric prediction models; impact of surface properties on dryline and MCS evolution; a numerical simulation of heavy precipitation over the complex topography of California; representing mesoscale fluxes induced by landscape discontinuities in global climate models; emphasizing the role of subgrid-scale heterogeneity in surface-air interaction; and problems with modeling and measuring biosphere-atmosphere exchanges of energy, water, and carbon on large scales
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Coherent interaction of atoms with a beam of light confined in a light cage
Controlling coherent interaction between optical fields and quantum systems in scalable, integrated platforms is essential for quantum technologies. Miniaturised, warm alkali-vapour cells integrated with on-chip photonic devices represent an attractive system, in particular for delay or storage of a single-photon quantum state. Hollow-core fibres or planar waveguides are widely used to confine light over long distances enhancing light-matter interaction in atomic-vapour cells. However, they suffer from inefficient filling times, enhanced dephasing for atoms near the surfaces, and limited light-matter overlap. We report here on the observation of modified electromagnetically induced transparency for a non-diffractive beam of light in an on-chip, laterally-accessible hollow-core light cage. Atomic layer deposition of an alumina nanofilm onto the light-cage structure was utilised to precisely tune the high-transmission spectral region of the light-cage mode to the operation wavelength of the atomic transition, while additionally protecting the polymer against the corrosive alkali vapour. The experiments show strong, coherent light-matter coupling over lengths substantially exceeding the Rayleigh range. Additionally, the stable non-degrading performance and extreme versatility of the light cage provide an excellent basis for a manifold of quantum-storage and quantum-nonlinear applications, highlighting it as a compelling candidate for all-on-chip, integrable, low-cost, vapour-based photon delay
Quantum corrections to the ground state energy of a trapped Bose-Einstein condensate: A diffusion Monte Carlo calculation
The diffusion Monte Carlo method is applied to describe a trapped atomic
Bose-Einstein condensate at zero temperature, fully quantum mechanically and
nonperturbatively. For low densities, [n(0): peak
density, a: s-wave scattering length], our calculations confirm that the exact
ground state energy for a sum of two-body interactions depends on only the
atomic physics parameter a, and no other details of the two-body model
potential. Corrections to the mean-field Gross-Pitaevskii energy range from
being essentially negligible to about 20% for N=2-50 particles in the trap with
positive s-wave scattering length a=100-10000 a.u.. Our numerical calculations
confirm that inclusion of an additional effective potential term in the
mean-field equation, which accounts for quantum fluctuations [see e.g. E.
Braaten and A. Nieto, Phys. Rev. B 56}, 14745 (1997)], leads to a greatly
improved description of trapped Bose gases.Comment: 7 pages, 4 figure
Development of Middle Stone Age innovation linked to rapid climate change
The development of modernity in early human populations has been linked to pulsed phases of technological and behavioural innovation within the Middle Stone Age of South Africa. However, the trigger for these intermittent pulses of technological innovation is an enigma. Here we show that, contrary to some previous studies, the occurrence of innovation was tightly linked to abrupt climate change. Major innovational pulses occurred at times when South African climate changed rapidly towards more humid conditions, while northern sub-Saharan Africa experienced widespread droughts, as the Northern Hemisphere entered phases of extreme cooling. These millennial-scale teleconnections resulted from the bipolar seesaw behaviour of the Atlantic Ocean related to changes in the ocean circulation. These conditions led to humid pulses in South Africa and potentially to the creation of favourable environmental conditions. This strongly implies that innovational pulses of early modern human behaviour were climatically influenced and linked to the adoption of refugia
Widespread seasonal gene expression reveals annual differences in human immunity and physiology.
Seasonal variations are rarely considered a contributing component to human tissue function or health, although many diseases and physiological process display annual periodicities. Here we find more than 4,000 protein-coding mRNAs in white blood cells and adipose tissue to have seasonal expression profiles, with inverted patterns observed between Europe and Oceania. We also find the cellular composition of blood to vary by season, and these changes, which differ between the United Kingdom and The Gambia, could explain the gene expression periodicity. With regards to tissue function, the immune system has a profound pro-inflammatory transcriptomic profile during European winter, with increased levels of soluble IL-6 receptor and C-reactive protein, risk biomarkers for cardiovascular, psychiatric and autoimmune diseases that have peak incidences in winter. Circannual rhythms thus require further exploration as contributors to various aspects of human physiology and disease.The Gambian study providing data for analysis was supported by core funding MC-A760-5QX00 to the International Nutrition Group by the UK Medical Research Council (MRC) and the UK Department for the International Development (DFID) under the MRC/DFID Concordat agreement. This work was supported by the JDRF UK Centre for Diabetes-Genes, Autoimmunity and Prevention (D-GAP; 4-2007-1003), the JDRF (9-2011-253), the Wellcome Trust (WT061858/091157), the National Institute for Health Research Cambridge Biomedical Research Centre (CBRC) and the Medical Research Council (MRC) Cusrow Wadia Fund. The research leading to these results has received funding from the European Union’s 7th Framework Programme (FP7/2007–2013) under grant agreement no.241447 (NAIMIT). The Cambridge Institute for Medical Research (CIMR) is in receipt of a Wellcome Trust Strategic Award (WT100140). X.C.D. was a University of Cambridge/Wellcome Trust Infection and Immunity PhD student. R.C.F. is funded by a JDRF post-doctoral fellowship (3-2011-374). C.W. and H.G are funded by the Wellcome Trust (WT089989). The BABYDIET study was supported by grants from the Deutsche Forschungsgemeinschaft (DFG ZI-310/14-1 to-4), the JDRF (JDRF 17-2012-16 and 1-2006-665) and the German Center for Diabetes Research (DZD e.V.). E.B. is supported by the DFG Research Center and Cluster of Excellence—Center for Regenerative Therapies Dresden (FZ 111).This is the final published version. It first appeared at http://www.nature.com/ncomms/2015/150512/ncomms8000/full/ncomms8000.html
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