280 research outputs found

    Protein-Energy Undernutrition Among Elderly Hospitalized Patients: A Prospective Study

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    Context: Numerous studies have identified strong correlations between the severity of nutritional deficits and an increased risk of subsequent morbid events among the hospitalized elderly, but whether inadequate nutrient intake during hospitalization contributes to such nutritional deficits or the risk of adverse outcomes is not known. Objectives: To identify the distribution of average daily nutrient intake among the nonter–minally ill hospitalized elderly, ascertain what factors contribute to persistently low intakes, and determine whether the adequacy of nutrient intake correlates with the risk of mortality. Design: Prospective cohort study conducted from 1994 to 1997. Setting: University-affiliated Department of Veterans Affairs hospital. Patients: A total of 497 patients 65 years or older (mean [SD] age, 74 [6] years; 97% male; 86% white) with a length of stay of 4 days or more. Main Outcome Measures: Daily in-hospital nutrient intake, in-hospital mortality, and 90-day mortality. Results: A total of 102 patients (21%) had an average daily in-hospital nutrient intake of <50% of their calculated maintenance energy requirements. Admission illness severity, average length of stay, and admission albumin and prealbumin levels for this low nutrient group did not differ significantly from those of the remaining patients. However, the low nutrient group had lower mean (SD) discharge serum total cholesterol (154 [44] mg/dL [4 [1.1] mmol/L] vs 173 [42] mg/dL [4.5 [1.1] mmol/L]; p = .001), albumin (29.1 [6.7] vs 33.2 [6.1] g/L, p = .001), and prealbumin (162 [69] vs 205 [68] mg/L;p = .001) concentrations and a higher rate of in-hospital mortality (relative risk, 8.0; 95% confidence interval, 2.8 to 22.6) and 90-day mortality (relative risk, 2.9; 95% confidence interval, 1.4 to 6.1). Contributing to the problem of inadequate nutrient intake, patients were frequently ordered to have nothing by mouth and were not fed by another route. Neither canned supplements nor nutrition support were used effectively. Conclusions: Throughout their hospitalization, many elderly patients were maintained on nutrient intakes far less than their estimated maintenance energy requirements, which may contribute to an increased risk of mortality. Given the difficulties reversing established nutritional deficits in the elderly, greater efforts should be made to prevent the development of such deficits during hospitalization. (JAMA 281:2013–2019, 1999)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68391/2/10.1177_088453369901400610.pd

    Clinical Research: Establishing a Comprehensive Database for Home Parenteral Nutrition: Six Years of Data

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141734/1/ncp0279.pd

    Stirling Convertor Fasteners Reliability Quantification

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    Onboard Radioisotope Power Systems (RPS) being developed for NASA s deep-space science and exploration missions require reliable operation for up to 14 years and beyond. Stirling power conversion is a candidate for use in an RPS because it offers a multifold increase in the conversion efficiency of heat to electric power and reduced inventory of radioactive material. Structural fasteners are responsible to maintain structural integrity of the Stirling power convertor, which is critical to ensure reliable performance during the entire mission. Design of fasteners involve variables related to the fabrication, manufacturing, behavior of fasteners and joining parts material, structural geometry of the joining components, size and spacing of fasteners, mission loads, boundary conditions, etc. These variables have inherent uncertainties, which need to be accounted for in the reliability assessment. This paper describes these uncertainties along with a methodology to quantify the reliability, and provides results of the analysis in terms of quantified reliability and sensitivity of Stirling power conversion reliability to the design variables. Quantification of the reliability includes both structural and functional aspects of the joining components. Based on the results, the paper also describes guidelines to improve the reliability and verification testing

    Association of Parenteral Nutrition Catheter Sepsis with Urinary Tract Infections

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141954/1/jpen0639.pd

    Ancient Lowland Maya neighborhoods: Average Nearest Neighbor analysis and kernel density models, environments, and urban scale

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    Many humans live in large, complex political centers, composed of multi-scalar communities including neighborhoods and districts. Both today and in the past, neighborhoods form a fundamental part of cities and are defined by their spatial, architectural, and material elements. Neighborhoods existed in ancient centers of various scales, and multiple methods have been employed to identify ancient neighborhoods in archaeological contexts. However, the use of different methods for neighborhood identification within the same spatiotemporal setting results in challenges for comparisons within and between ancient societies. Here, we focus on using a single method—combining Average Nearest Neighbor (ANN) and Kernel Density (KD) analyses of household groups—to identify potential neighborhoods based on clusters of households at 23 ancient centers across the Maya Lowlands. While a one-size-fits all model does not work for neighborhood identification everywhere, the ANN/KD method provides quantifiable data on the clustering of ancient households, which can be linked to environmental zones and urban scale. We found that centers in river valleys exhibited greater household clustering compared to centers in upland and escarpment environments. Settlement patterns on flat plains were more dispersed, with little discrete spatial clustering of households. Furthermore, we categorized the ancient Maya centers into discrete urban scales, finding that larger centers had greater variation in household spacing compared to medium-sized and smaller centers. Many larger political centers possess heterogeneity in household clustering between their civic-ceremonial cores, immediate hinterlands, and far peripheries. Smaller centers exhibit greater household clustering compared to larger ones. This paper quantitatively assesses household clustering among nearly two dozen centers across the Maya Lowlands, linking environment and urban scale to settlement patterns. The findings are applicable to ancient societies and modern cities alike; understanding how humans form multi-scalar social groupings, such as neighborhoods, is fundamental to human experience and social organization

    Searches for Neutrinos from Gamma-Ray Bursts Using the IceCube Neutrino Observatory

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    Gamma-ray bursts (GRBs) are considered as promising sources of ultra-high-energy cosmic rays (UHECRs) due to their large power output. Observing a neutrino flux from GRBs would offer evidence that GRBs are hadronic accelerators of UHECRs. Previous IceCube analyses, which primarily focused on neutrinos arriving in temporal coincidence with the prompt gamma-rays, found no significant neutrino excess. The four analyses presented in this paper extend the region of interest to 14 days before and after the prompt phase, including generic extended time windows and targeted precursor searches. GRBs were selected between 2011 May and 2018 October to align with the data set of candidate muon-neutrino events observed by IceCube. No evidence of correlation between neutrino events and GRBs was found in these analyses. Limits are set to constrain the contribution of the cosmic GRB population to the diffuse astrophysical neutrino flux observed by IceCube. Prompt neutrino emission from GRBs is limited to ≲1% of the observed diffuse neutrino flux, and emission on timescales up to 104 s is constrained to 24% of the total diffuse flux.Peer Reviewe

    A search for time-dependent astrophysical neutrino emission with IceCube data from 2012 to 2017

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    High-energy neutrinos are unique messengers of the high-energy universe, tracing the processes of cosmic-ray acceleration. This paper presents analyses focusing on time-dependent neutrino point-source searches. A scan of the whole sky, making no prior assumption about source candidates, is performed, looking for a space and time clustering of high-energy neutrinos in data collected by the IceCube Neutrino Observatory between 2012 and 2017. No statistically significant evidence for a time-dependent neutrino signal is found with this search during this period since all results are consistent with the background expectation. Within this study period, the blazar 3C 279, showed strong variability, inducing a very prominent gamma-ray flare observed in 2015 June. This event motivated a dedicated study of the blazar, which consists of searching for a time-dependent neutrino signal correlated with the gamma-ray emission. No evidence for a time-dependent signal is found. Hence, an upper limit on the neutrino fluence is derived, allowing us to constrain a hadronic emission model
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