2,118 research outputs found

    CHOLESTEROL LOWERING AND THE RISK OF CORONARY HEART DISEASE

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24843/1/0000269.pd

    Evaluation of a proposal for reliable low-cost grid power with 100% wind, water, and solar

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    A number of analyses, meta-Analyses, and assessments, including those performed by the Intergovernmental Panel on Climate Change, the National Oceanic and Atmospheric Administration, the National Renewable Energy Laboratory, and the International Energy Agency, have concluded that deployment of a diverse portfolio of clean energy technologies makes a transition to a low-carbon-emission energy system both more feasible and less costly than other pathways. In contrast, Jacobson et al. [Jacobson MZ, Delucchi MA, Cameron MA, Frew BA (2015) Proc Natl Acad Sci USA 112(49):15060-15065] argue that it is feasible to provide low-cost solutions to the grid reliability problem with 100% penetration of WWS [wind, water and solar power] across all energy sectors in the continental United States between 2050 and 2055 , with only electricity and hydrogen as energy carriers. In this paper, we evaluate that study and find significant shortcomings in the analysis. In particular, we point out that this work used invalid modeling tools, contained modeling errors, and made implausible and inadequately supported assumptions. Policy makers should treat with caution any visions of a rapid, reliable, and low-cost transition to entire energy systems that relies almost exclusively on wind, solar, and hydroelectric power

    Rectal Transmission of Transmitted/Founder HIV-1 Is Efficiently Prevented by Topical 1% Tenofovir in BLT Humanized Mice

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    Rectal microbicides are being developed to prevent new HIV infections in both men and women. We focused our in vivo preclinical efficacy study on rectally-applied tenofovir. BLT humanized mice (n = 43) were rectally inoculated with either the primary isolate HIV-1(JRCSF) or the MSM-derived transmitted/founder (T/F) virus HIV-1(THRO) within 30 minutes following treatment with topical 1% tenofovir or vehicle. Under our experimental conditions, in the absence of drug treatment we observed 50% and 60% rectal transmission by HIV-1(JRCSF) and HIV-1(THRO), respectively. Topical tenofovir reduced rectal transmission to 8% (1/12; log rank p = 0.03) for HIV-1(JRCSF) and 0% (0/6; log rank p = 0.02) for HIV-1(THRO). This is the first demonstration that any human T/F HIV-1 rectally infects humanized mice and that transmission of the T/F virus can be efficiently blocked by rectally applied 1% tenofovir. These results obtained in BLT mice, along with recent ex vivo, Phase 1 trial and non-human primate reports, provide a critically important step forward in the development of tenofovir-based rectal microbicides

    Concentración, segregación y movilidad residencial de los extranjeros en Barcelona

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    El artículo analiza la dinámica residencial de la población extranjera en la ciudad de Barcelona, considerando tres aspectos que centran su distribución: la concentración en el territorio, la segregación residencial en relación con la población de la ciudad y la movilidad residencial en interrelación con su región metropolitana. Se realiza un análisis temporal que sigue la evolución de estos elementos a lo largo de la década, con el objetivo de aportar una visión de conjunto de los cambios observados. El análisis contempla la utilización de diferentes fuentes estadísticas y detalla el comportamiento de las nacionalidades con más efectivos en Barcelona. Los resultados indican un desplazamiento de las áreas de concentración desde el centro histórico hacia la periferia de la ciudad, un descenso de la segregación vinculado a una mayor dispersión territorial y una fuerte movilidad residencial dentro de la Región Metropolitana que afecta especialmente a los municipios situados en la periferia más próxima a la ciudad.L'article analitza la dinàmica residencial de la població estrangera a la ciutat de Barcelona, considerant tres dels aspectes que en centren la distribució: la concentració en el territori, la segregació residencial en relació amb la població de la ciutat i la mobilitat residencial en interrelació amb la seva regió metropolitana. S'hi realitza una anàlisi temporal que ressegueix l'evolució d'aquests elements al llarg de la darrera dècada, amb l'objectiu d'aportar una visió de conjunt dels canvis observats. L'estudi contempla la utilització de diferents fonts estadístiques i detalla el comportament de les nacionalitats amb més efectius a Barcelona. Els resultats indiquen un desplaçament de les àrees de concentració des del centre històric cap a la perifèria de la ciutat, un descens de la segregació lligat a una dispersió territorial més gran i una forta mobilitat residencial dins de la Regió Metropolitana que afecta especialment els municipis situats a la perifèria més pròxima a la ciutat.L'article analyse la dynamique résidentielle de la population étrangère dans la ville de Barcelone en se concentrant sur trois aspects de sa distribution : la concentration sur le territoire, la ségrégation et la mobilité résidentielle au sein de la région métropolitaine. L'évolution de ces trois facteurs a été suivie pendant une décennie dans le but d'obtenir une vision globale des changements observés. Diverses sources statistiques qui détaillent le comportement des populations les plus nombreuses habitant Barcelone ont été utilisées. Les résultats montrent un déplacement des zones de concentration des étrangers depuis le centre historique vers les périphéries, une diminution de la ségrégation due à la croissante dispersion territoriale, et finalement une forte mobilité résidentielle dans la Région Métropolitaine, particulièrement dans les communes les plus proches de Barcelone.Three aspects of foreigners' residential mobility in the city of Barcelona are studied in this paper: territorial concentration, segregation and residential change within the metropolitan region. To obtain a global view, these three elements are followed for a decade. Several data bases, specifying the behaviour of major nationalities, are used. Results firstly show that foreigners are gradually moving out of the historical centre and into the periphery. Secondly, that there is a strong intra-metropolitan mobility, particularly so in the municipalities nearest to the central city. Finally, as foreigners are more widely distributed throughout the territory, they are also becoming less segregated

    Older Norwegians' understanding of loneliness

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    This interpretive study explored older people's understanding of loneliness and what they considered appropriate and effective ways of dealing with it. Thirty elderly people were interviewed in-depth; 12 described themselves as “lonely” and 18 as “not lonely.” We found a striking difference in the way “lonely” and “not lonely” people talked about loneliness. The “not lonely” participants described loneliness as painful, caused by the person's negative way of behaving and a state they should pull themselves out of. The “lonely” participants also described loneliness as painful, and gave more detailed descriptions of loneliness as disconnection from others, from their former home and from today's society. The “lonely” participants were more reserved and subdued in trying to explain loneliness, attributing it partly to themselves, but mostly to the lack of social contact with important others. Some felt able to handle their loneliness, while others felt unable to cope. This study underlines the importance of subjective experiences in trying to understand a phenomenon like loneliness and of developing support for lonely older people unable to cope on their own

    LSST Science Book, Version 2.0

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    A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be 24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with δ<+34.5\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

    What factors influence the rediscovery of lost tetrapod species?

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    We created a database of lost and rediscovered tetrapod species, identified patterns in their distribution and factors influencing rediscovery. Tetrapod species are being lost at a faster rate than they are being rediscovered, due to slowing rates of rediscovery for amphibians, birds and mammals, and rapid rates of loss for reptiles. Finding lost species and preventing future losses should therefore be a conservation priority. By comparing the taxonomic and spatial distribution of lost and rediscovered tetrapod species, we have identified regions and taxa with many lost species in comparison to those that have been rediscovered—our results may help to prioritise search effort to find them. By identifying factors that influence rediscovery, we have improved our ability to broadly distinguish the types of species that are likely to be found from those that are not (because they are likely to be extinct). Some lost species, particularly those that are small and perceived to be uncharismatic, may have been neglected in terms of conservation effort, and other lost species may be hard to find due to their intrinsic characteristics and the characteristics of the environments they occupy (e.g. nocturnal species, fossorial species and species occupying habitats that are more difficult to survey such as wetlands). These lost species may genuinely await rediscovery. However, other lost species that possess characteristics associated with rediscovery (e.g. large species) and that are also associated with factors that negatively influence rediscovery (e.g. those occupying small islands) are more likely to be extinct. Our results may foster pragmatic search protocols that prioritise lost species likely to still exist.Israel Science Foundation http://dx.doi.org/10.13039/501100003977Leibniz‐Institut für Gewässerökologie und BinnenfischereiAlexander von Humboldt‐StiftungPontificia Universidad Católica del Ecuador http://dx.doi.org/10.13039/501100011749Peer Reviewe

    Accurate microRNA target prediction correlates with protein repression levels

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    MicroRNAs are small endogenously expressed non-coding RNA molecules that regulate target gene expression through translation repression or messenger RNA degradation. MicroRNA regulation is performed through pairing of the microRNA to sites in the messenger RNA of protein coding genes. Since experimental identification of miRNA target genes poses difficulties, computational microRNA target prediction is one of the key means in deciphering the role of microRNAs in development and diseas

    Dysfunction in the βII Spectrin-Dependent Cytoskeleton Underlies Human Arrhythmia.

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    Background: The cardiac cytoskeleton plays key roles in maintaining myocyte structural integrity in health and disease. In fact, human mutations in cardiac cytoskeletal elements are tightly linked with cardiac pathologies including myopathies, aortopathies, and dystrophies. Conversely, the link between cytoskeletal protein dysfunction in cardiac electrical activity is not well understood, and often overlooked in the cardiac arrhythmia field. Methods and Results: Here, we uncover a new mechanism for the regulation of cardiac membrane excitability. We report that βII spectrin, an actin-associated molecule, is essential for the post-translational targeting and localization of critical membrane proteins in heart. βII spectrin recruits ankyrin-B to the cardiac dyad, and a novel human mutation in the ankyrin-B gene disrupts the ankyrin-B/βII spectrin interaction leading to severe human arrhythmia phenotypes. Mice lacking cardiac βII spectrin display lethal arrhythmias, aberrant electrical and calcium handling phenotypes, and abnormal expression/localization of cardiac membrane proteins. Mechanistically, βII spectrin regulates the localization of cytoskeletal and plasma membrane/sarcoplasmic reticulum protein complexes that include the Na/Ca exchanger, RyR2, ankyrin-B, actin, and αII spectrin. Finally, we observe accelerated heart failure phenotypes in βII spectrin-deficient mice. Conclusions: Our findings identify βII spectrin as critical for normal myocyte electrical activity, link this molecule to human disease, and provide new insight into the mechanisms underlying cardiac myocyte biology
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