2,620 research outputs found

    P2‐540: Polygenetic Risk For Alzheimer’S Disease And Dementia Status

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153242/1/alzjjalz2019062948.pd

    The Role of Demographic and Clinical Characteristics on Risk of COVID-19 Related Infection and Mortality

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    Since the emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) which causes Covid-19, global health systems have struggled to cope with the rising number of related infections, acute admissions and mortalities. Poorer clinical outcomes have been observed amongst older patients with Covid-19 and males, and in those who are obese or who have darker skin(1) . Additionally, poorer outcomes including increased mortality have been associated with low vitamin D status(2,3) . The current observational study aimed to elucidate the association between patient demographic, anthropometric, clinical and biometric characteristics and Covid-19 disease severity and mortality

    Influence of Gamma-Ray Emission on the Isotopic Composition of Clouds in the Interstellar Medium

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    We investigate one mechanism of the change in the isotopic composition of cosmologically distant clouds of interstellar gas whose matter was subjected only slightly to star formation processes. According to the standard cosmological model, the isotopic composition of the gas in such clouds was formed at the epoch of Big Bang nucleosynthesis and is determined only by the baryon density in the Universe. The dispersion in the available cloud composition observations exceeds the errors of individual measurements. This may indicate that there are mechanisms of the change in the composition of matter in the Universe after the completion of Big Bang nucleosynthesis. We have calculated the destruction and production rates of light isotopes (D, 3He, 4He) under the influence of photonuclear reactions triggered by the gamma-ray emission from active galactic nuclei (AGNs). We investigate the destruction and production of light elements depending on the spectral characteristics of the gamma-ray emission. We show that in comparison with previous works, taking into account the influence of spectral hardness on the photonuclear reaction rates can increase the characteristic radii of influence of the gamma-ray emission from AGNs by a factor of 2-8. The high gamma-ray luminosities of AGNs observed in recent years increase the previous estimates of the characteristic radii by two orders of magnitude. This may suggest that the influence of the emission from AGNs on the change in the composition of the medium in the immediate neighborhood (the host galaxy) has been underestimated.Comment: 13 pages, 13 figures, 3 table

    P3‐558: Exposures Prior To Age 16 Are Associated With Dementia Status In The Health And Retirement Study

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152762/1/alzjjalz2019063595.pd

    Photodisintegration of the triton with realistic potentials

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    The process γ+tn+d\gamma + t \to n + d is treated by means of three-body integral equations employing in their kernel the W-Matrix representation of the subsystem amplitudes. As compared to the plane wave (Born) approximation the full solution of the integral equations, which takes into account the final state interaction, shows at low energies a 24% enhancement. The calculations are based on the semirealistic Malfliet-Tjon and the realistic Paris and Bonn B potentials. For comparison with earlier calculations we also present results for the Yamaguchi potential. In the low-energy region a remarkable potential dependence is observed, which vanishes at higher energies.Comment: 16 pages REVTeX, 8 postscript figures included, uses epsfig.st

    Radiative decay of a massive particle and the non-thermal process in primordial nucleosynthesis

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    We consider the effects on big bang nucleosynthesis (BBN) of the radiative decay of a long-lived massive particle. If high-energy photons are emitted after the BBN epoch (t1103t \sim 1 - 10^3 sec), they may change the abundances of the light elements through photodissociation processes, which may result in a significant discrepancy between standard BBN and observation. Taking into account recent observational and theoretical developments in this field, we revise our previous study constraining the abundance of the radiatively-decaying particles. In particular, on the theoretical side, it was recently claimed that the non-thermal production of 6^6Li, which is caused by the photodissociation of \hefour, most severely constrains the abundance of the radiatively-decaying particle. We will see, however, it is premature to emphasize the importance of the non-thermal production of 6^6Li because (i) the theoretical computation of the 6^6Li abundance has large uncertainty due to the lack of the precise understanding of the 6^6Li production cross section, and (ii) the observational data of 6^6Li abundance has large errors.Comment: 15 pages, using REVTeX and 3 postscript figure

    Designing Research

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    The aim of this chapter is to set out a process that researchers can follow to design a robust quantitative research study of occupant behavior in buildings. Central to this approach is an emphasis on intellectual clarity around what is being measured and why. To help achieve this clarity, researchers are encouraged to literally draw these relationships out in the form of a concept map capturing the theoretical model of the cause and effect between occupant motivations and energy use. Having captured diagrammatically how the system is thought to work, the next step is to formulate research questions or hypotheses capturing the relationship between variables in the theoretical model, and to start to augment the diagram with the measurands (things that can actually be measured) that are good proxies for each concept. Once these are identified, the diagram can be further augmented with one or more methods of measuring each measurand. The chapter argues that it is necessary to carefully define concepts and their presumed relationships, and to clearly state research questions and identify what the researcher intends to measure before starting data collection. The chapter also explains the ideas of reliability, validity, and uncertainty, and why knowledge about them is essential for any researcher

    On reminder effects, drop-outs and dominance: evidence from an online experiment on charitable giving

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    We present the results of an experiment that (a) shows the usefulness of screening out drop-outs and (b) tests whether different methods of payment and reminder intervals affect charitable giving. Following a lab session, participants could make online donations to charity for a total duration of three months. Our procedure justifying the exclusion of drop-outs consists in requiring participants to collect payments in person flexibly and as known in advance and as highlighted to them later. Our interpretation is that participants who failed to collect their positive payments under these circumstances are likely not to satisfy dominance. If we restrict the sample to subjects who did not drop out, but not otherwise, reminders significantly increase the overall amount of charitable giving. We also find that weekly reminders are no more effective than monthly reminders in increasing charitable giving, and that, in our three months duration experiment, standing orders do not increase giving relative to one-off donations

    Racial and Ethnic Differences in Knowledge About One’s Dementia Status

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156478/1/jgs16442.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156478/3/jgs16442_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156478/2/jgs16442-sup-0001-supinfo.pd
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