80 research outputs found

    Orbit spaces of free involutions on the product of two projective spaces

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    Let XX be a finitistic space having the mod 2 cohomology algebra of the product of two projective spaces. We study free involutions on XX and determine the possible mod 2 cohomology algebra of orbit space of any free involution, using the Leray spectral sequence associated to the Borel fibration XXZ2BZ2X \hookrightarrow X_{\mathbb{Z}_2} \longrightarrow B_{\mathbb{Z}_2}. We also give an application of our result to show that if XX has the mod 2 cohomology algebra of the product of two real projective spaces (respectively complex projective spaces), then there does not exist any Z2\mathbb{Z}_2-equivariant map from SkX\mathbb{S}^k \to X for k2k \geq 2 (respectively k3k \geq 3), where Sk\mathbb{S}^k is equipped with the antipodal involution.Comment: 14 pages, to appear in Results in Mathematic

    Rising rural body-mass index is the main driver of the global obesity epidemic in adults

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    Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities 1,2 . This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity 3�6 . Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55 of the global rise in mean BMI from 1985 to 2017�and more than 80 in some low- and middle-income regions�was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing�and in some countries reversal�of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories. © 2019, The Author(s)

    A century of trends in adult human height

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    Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5-22.7) and 16.5 cm (13.3-19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8-144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries

    Two-phase microfluidics in electrowetting displays and its effect on optical performance

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    Driving microfluidic flow in micropixels by electrowetting to realize light switches and displays is of both practical and fundamental significance. The electro-optical performance related to microfluidic behavior needs to be clarified to optimize device functions. In this article, the microfluidic performance in electrowetting display devices was categorized according to the oil-water interface shape and response. The oil film movement was divided into vertically "thinning" and transversally "opening," for which the "thinning" process was found the key factor determining the pixel switching speed rather than the "opening" process. Therefore, the breakup point and the oil film thickness were critical, which could be controlled by surface wettability and oil volume. We have also realized a new oil filling method with controllable dosing volume assisted by the microfluidic creation of microdroplets. This study could help quantitatively understand electrowetting display performance in both its theoretical and practical aspects

    Absence of Stress Response in Dorsal Raphe Nucleus in Modulator of Apoptosis 1-Deficient Mice

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    10.1007/s12035-018-1205-7Molecular Neurobiology1-17MONB

    A ReaxFF Molecular Dynamics Study of Hydrogen Diffusion in Ruthenium-The Role of Grain Boundaries

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    Ruthenium (Ru) thin films are used as protective caps for the multilayer mirrors in extreme ultraviolet lithography machines. When these mirrors are exposed to atomic hydrogen (H), it can permeate through Ru, leading to the formation of hydrogen-filled blisters on the mirrors. H has been shown to exhibit low solubility in bulk Ru, but the nature of H diffusion through Ru and its contribution to the mechanisms of blistering remain unknown. This work makes use of reactive molecular dynamics simulations to study the influence of imperfections in a Ru film on the behavior of H. For the Ru/H system, a ReaxFF force field which reproduces structures and energies obtained from quantum-mechanical calculations was parametrized. Molecular dynamics simulations have been performed with the newly developed force field to study the effect of tilt and twist grain boundaries on the overall diffusion behavior of H in Ru. Our simulations show that the tilt and twist grain boundaries provide energetically favorable sites for hydrogen atoms and act as sinks and highways for H. They therefore block H transport across their planes and favor diffusion along their planes. This results in the accumulation of hydrogen at the grain boundaries. The strong effect of the grain boundaries on hydrogen diffusion suggests tailoring the morphology of ruthenium thin films as a means to curb the rate of hydrogen permeation

    Primary Tracheal Lymphoma Causing Respiratory Failure

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