9,836 research outputs found

    B cell responses in murine influenza

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    Mining topological relations from the web

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    Topological relations between geographic regions are of interest in many applications. When the exact boundaries of regions are not available, such relations can be established by analysing natural language information from web documents. In particular we demonstrate how redundancy-based techniques can be used to acquire containment and adjacency relations, and how fuzzy spatial reasoning can be employed to maintain the consistency of the resulting knowledge base

    Twentieth-century Trends in the Annual Cycle of Temperature across the Northern Hemisphere

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    The annual cycle of surface air temperature is examined across Northern Hemisphere land areas (north of 25°N) by comparing the results from CRUTS against four reanalysis datasets: two versions of the Twentieth Century Reanalysis (20CR and 20CRC) and two versions of the ERA-CLIM reanalyses (ERA-20C and ERA-20CM). The Modulated Annual Cycle is adaptively derived from an Ensemble Empirical Mode Decomposition (EEMD) filter, and is used to define the phase and amplitude of the annual cycle. The EEMD method does not impose a simple sinusoidal shape of the annual cycle. None of the reanalysis simulations assimilate surface temperature data, but differ in the parameters that are included: both ERA-20C and 20CR assimilate surface pressure data; ERA-20C also includes surface wind data over the oceans; ERA-20CM does not assimilate any of these synoptic data; and none of the reanalyses assimilate land-use data. It is demonstrated that synoptic variability is critical for explaining the trends and variability of the annual cycle of surface temperature across the northern hemisphere. The CMIP5 forcings alone are insufficient to explain the observed trends and decadal-scale variability, particularly with respect to the decline in the amplitude of the annual cycle throughout the twentieth century. The variability in the annual cycle during the latter half of the twentieth century was unusual in the context of the twentieth century, and was most likely related to large-scale atmospheric variability, although uncertainty in the results is greatest before ca. 1930

    In Memoriam: Keith R. Briffa, 1952–2017

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    Keith R. Briffa was one of the most influential palaeoclimatologists of the last 30 years. His primary research interests lay in Late-Holocene climate change with a geographical emphasis on northern Eurasia. His greatest impact was in the field of dendroclimatology, a field that he helped to shape. His contributions have been seminal to the development of sound methods for tree-ring analysis and in their proper application to allow the interpretation of climate variability from tree rings. This led to the development of many important records that allow us to understand natural climate variability on timescales from years to millennia and to set recent climatic trends in their historical context

    Interactions of atoms with high‐field single‐cycle infrared radiation

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    We have studied ionization and excitation of Rydberg atoms by intense sub‐picosecond electromagnetic field pulses of less than one cycle duration. The ionization threshold electric field scales as the binding energy (i.e., n∗−2, rather than the n∗−4 threshold scaling characteristic of static field ionization and high order multiphoton ionization. This altered behavior is due to the short duration and the subcycle nature of the field. We also find a wide distribution of final states produced by these pulses, which are effectively ‘‘in resonance’’ for dozens of transitions simultaneously.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87507/2/227_1.pd

    The Influence of Race on Health Status Outcomes One Year After an Acute Coronary Syndrome

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    ObjectivesThe goal of this study was to compare health status (symptoms, function, and quality of life) outcomes of whites and blacks one year after an acute coronary syndrome (ACS).BackgroundAlthough racial differences in the use of angiography and revascularization after ACS are known to exist, differences in health status outcomes have not been described.MethodsWe conducted a prospective registry of 1,159 consecutive ACS patients treated between February 1, 2000 and October 31, 2001. One-year health status was quantified with the Seattle Angina Questionnaire (SAQ) and Short Form-12 Physical Component Score (SF-12 PCS). Multivariable models were used to adjust for racial differences in sociodemographic, clinical, and treatment characteristics.ResultsMortality rates were similar among the 196 black and 963 white patients (7.1% vs. 7.0%, p = 0.93); 81 died during follow-up, and 199 (17%) could not be interviewed. At one year, blacks had a higher prevalence of angina (43.4% vs. 27.1%), worse quality of life (SAQ score = 70.6 ± 28.3 vs. 83.9 ± 20.8), and poorer physical function (SF-12 PCS = 36.8 ± 12.3 vs. 43.2 ± 11.4; p < 0.0001 for all). Multivariable models, including hospital treatments, revealed a trend for more angina (odds ratio 1.46 [95% confidence interval 0.91 to 2.34]) and significantly worse quality of life (mean difference = −7.7 ± 2.4, p = 0.002) and physical function (−3.6 ± 1.3, p = 0.005).ConclusionsBlacks have more angina, worse quality of life, and worse physical function one year after an ACS than do whites. Closer surveillance of black ACS patients is needed to determine whether additional treatment can improve their outcomes
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