467 research outputs found

    A New Measurement of the Temperature Density Relation of the IGM From Voigt Profile Fitting

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    We decompose the Lyman-{\alpha} (Ly{\alpha}) forest of an extensive sample of 74 high signal-to-noise ratio and high-resolution quasar spectra into a collection of Voigt profiles. Absorbers located near caustics in the peculiar velocity field have the smallest Doppler parameters, resulting in a low-bb cutoff in the bb-NHIN_{\text{HI}} set by the thermal state of intergalactic medium (IGM). We fit this cutoff as a function of redshift over the range 2.0z3.42.0\leq z \leq 3.4, which allows us to measure the evolution of the IGM temperature-density (T=T0(ρ/ρ0)γ1T= T_0 (\rho/ \rho_0)^{\gamma-1}) relation parameters T0T_0 and γ\gamma. We calibrate our measurements against Lyα\alpha forest simulations, using 21 different thermal models of the IGM at each redshift, also allowing for different values of the IGM pressure smoothing scale. We adopt a forward-modeling approach and self-consistently apply the same algorithms to both data and simulations, propagating both statistical and modeling uncertainties via Monte Carlo. The redshift evolution of T0T_0 shows a suggestive peak at z=2.8z=2.8, while our evolution of γ\gamma is consistent with γ1.4\gamma\simeq 1.4 and disfavors inverted temperature-density relations. Our measured evolution of T0T_0 and γ\gamma are generally in good agreement with previous determinations in the literature. Both the peak in the evolution of T0T_0 at z=2.8z = 2.8, as well as the high temperatures T01500020000T_0\simeq 15000-20000\,K that we observe at 2.4<z<3.42.4 < z < 3.4, strongly suggest that a significant episode of heating occurred after the end of HI reionization, which was most likely the cosmic reionization of HeII.Comment: Accepted for publication in ApJ, 23 pages, 26 figures, machine readable tables available onlin

    Evaluation of an Activated Patient Diabetes Education Newsletter

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    This study evaluated a monthly; activated patient newsletter sent to over 7000 patients in Michigan with diabetes. The newsletter provided concise and action-oriented information about diabetes care. Patients who had signed up to receive the newsletter during the first 4 months of the project (1863) were surveyed to determine how many patients found the newsletter helpful; 80% (1498) of the patients replied. Patients who found the newsletter most helpful were older, had lower incomes, and reported more corrtplications, less understanding of diabetes, and being in poorer overall health. They also were more likely to have non-insulin-dependent diabetes mellitus (NIDDM) than insulin-dependent diabetes mellitus (IDDM). We concluded that the activated patient newsletter is a useful public health/patient education intervention for persons with diabetes. Such a newsletter should be part of a coordinated system of ongoing patient care, education, screening, and social and psychological support.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68904/2/10.1177_014572179402000106.pd

    Rank 3 permutation characters and maximal subgroups

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    In this paper we classify all maximal subgroups M of a nearly simple primitive rank 3 group G of type L=Omega_{2m+1}(3), m > 3; acting on an L-orbit E of non-singular points of the natural module for L such that 1_P^G <=1_M^G where P is a stabilizer of a point in E. This result has an application to the study of minimal genera of algebraic curves which admit group actions.Comment: 41 pages, to appear in Forum Mathematicu

    Psychophysical responses to earth-vertical rotations in the elderly

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    A growing elderly population is vulnerable to injury or death due to falls. Previous studies documenting the physiologic changes that occur within the vestibular system due to the aging process have shown moderate decreases in caloric and rotational chair responses. Psychophysical testing, which has proven to be critical to understanding the function of the auditory and other sensory systems, has not yet been used to study vestibular function in the elderly. The present study had two goals: to determine if psychophysical thresholds correlate with performance on standard tests of vestibular function, and to determine if older subjects have poorer vestibular psychophysical thresholds than younger subjects. Eighteen older adults (age range 63-84 years) and thirteen younger adults (age range 20-25 years) participated in the study. Psychophysical testing of vestibular function consisted of rotations about the earth-vertical axis to determine both detection thresholds and discrimination thresholds to angular velocity. Standard tests of vestibular function included sinusoidal harmonic oscillation, steps of velocity, and caloric testing. On average, older adults performed more poorly on psychophysical tests than their younger counterparts. The best older adults did as well as the best younger subjects on both detection and discrimination tasks, but the worst older adults were far poorer than the worst younger subjects. Psychophysical thresholds did not correspond to performance on rotational chair testing. These results demonstrate that normal older adults have a wider performance range than younger subjects on psychophysical testing. It also indicates that psychophysical testing accesses different information than standard tests of vestibular function. This suggests that psychophysical testing may be an important additional method for measuring balance function in the elderly

    The renal arterial resistance index and renal allograft survival

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    BACKGROUND: Most renal transplants fail because of chronic allograft nephropathy or because the recipient dies, but no reliable factor predicting long-term outcome has been identified. We tested whether a renal arterial resistance index of less than 80 was predictive of long-term allograft survival. METHODS: The renal segmental arterial resistance index (the percentage reduction of the end-diastolic flow as compared with the systolic flow) was measured by Doppler ultrasonography in 601 patients at least three months after transplantation between August 1997 and November 1998. All patients were followed for three or more years. The combined end point was a decrease of 50 percent or more in the creatinine clearance rate, allograft failure (indicated by the need for dialysis), or death. RESULTS: A total of 122 patients (20 percent) had a resistance index of 80 or higher. Eighty-four of these patients (69 percent) had a decrease of 50 percent or more in creatinine clearance, as compared with 56 of the 479 patients with a resistance index of less than 80 (12 percent); 57 patients with a higher resistance index (47 percent) required dialysis, as compared with 43 patients with a lower resistance index (9 percent); and 36 patients with a higher resistance index (30 percent) died, as compared with 33 patients with a lower resistance index (7 percent) (P<0.001 for all comparisons). A total of 107 patients with a higher resistance index (88 percent) reached the combined end point, as compared with 83 of those with a lower resistance index (17 percent, P<0.001). The multivariate relative risk of graft loss among patients with a higher resistance index was 9.1 (95 percent confidence interval, 6.6 to 12.7). Proteinuria (protein excretion, 1 g per day or more), symptomatic cytomegalovirus infection, and a creatinine clearance rate of less than 30 ml per minute per 1.73 m2 of body-surface area after transplantation also increased the risk. CONCLUSIONS: A renal arterial resistance index of 80 or higher measured at least three months after transplantation is associated with poor subsequent allograft performance and death

    Searching for real-world effectiveness versus efficacy of healthcare innovations: the case of social prescribing for diabetes

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    Background: Social prescribing is a process whereby primary care patients are linked or referred to nonmedical sources of support in the community and voluntary sector. It is a concept that has arisen in practice and implemented widely in the United Kingdom and has been evaluated by various organizations. Objective: The aim of our study was to characterize, collate, and analyze the evidence from evaluation of social prescribing for type 2 diabetes in the United Kingdom and Ireland, comparing information available on publicly available websites with the published literature. Methods: We used a broad, pragmatic definition of social prescribing and conducted Web-based searches for websites of organizations providing potentially relevant services. We also explored linked information. In parallel, we searched Medline, PubMed, Cochrane Library, Google Scholar, and reference lists for relevant studies published in peer-reviewed journals. We extracted the data systematically on the characteristics, any reported evaluation, outcomes measured and results, and terminology used to describe each service. Results: We identified 40 UK- or Ireland-based projects that referred people with type 2 diabetes and prediabetes to nonmedical interventions or services provided in the community. We located evaluations of 24 projects; 11 as published papers, 12 as Web-based reports, and 1 as both a paper and a Web-based report. The interventions and services identified included structured group educational programs, exercise referral schemes, and individualized advice and support with signposting of health-related activities in the community. Although specific interventions such as community-based group educational programs and exercise referral have been evaluated in randomized controlled trials, evaluation of individualized social prescribing services involving people with type 2 diabetes has, in most cases, used pre-post and mixed methods approaches. These evaluations report generic improvement in a broad range of outcomes and provide an insight into the criteria for the success of social prescribing services. Conclusions: Our study revealed the varied models of social prescribing and nonmedical, community-based services available to people with type 2 diabetes and the extent of evaluation of these, which would not have been achieved by searching databases alone. The findings of this scoping study do not prove that social prescribing is an effective measure for people with type 2 diabetes in the United Kingdom, but can be used to inform future evaluation and contribute to the development of the evidence base for social prescribing. Accessing Web-based information provides a potential method for investigating how specific innovative health concepts, such as social prescribing, have been translated, implemented, and evaluated in practice. Several challenges were encountered including defining the concept, focusing on process plus intervention, and searching diverse, evolving Web-based sources. Further exploration of this approach will inform future research on the application of innovative health care concepts into practice

    Ancient Yersinia pestis and Salmonella enterica genomes from Bronze Age Crete

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    During the late 3rd millennium BCE, the Eastern Mediterranean and Near East witnessed societal changes in many regions, which are usually explained with a combination of social and climatic factors.1, 2, 3, 4 However, recent archaeogenetic research forces us to rethink models regarding the role of infectious diseases in past societal trajectories.5 The plague bacterium Yersinia pestis, which was involved in some of the most destructive historical pandemics,5, 6, 7, 8 circulated across Eurasia at least from the onset of the 3rd millennium BCE,9, 10, 11, 12, 13 but the challenging preservation of ancient DNA in warmer climates has restricted the identification of Y. pestis from this period to temperate climatic regions. As such, evidence from culturally prominent regions such as the Eastern Mediterranean is currently lacking. Here, we present genetic evidence for the presence of Y. pestis and Salmonella enterica, the causative agent of typhoid/enteric fever, from this period of transformation in Crete, detected at the cave site Hagios Charalambos. We reconstructed one Y. pestis genome that forms part of a now-extinct lineage of Y. pestis strains from the Late Neolithic and Bronze Age that were likely not yet adapted for transmission via fleas. Furthermore, we reconstructed two ancient S. enterica genomes from the Para C lineage, which cluster with contemporary strains that were likely not yet fully host adapted to humans. The occurrence of these two virulent pathogens at the end of the Early Minoan period in Crete emphasizes the necessity to re-introduce infectious diseases as an additional factor possibly contributing to the transformation of early complex societies in the Aegean and beyond.Results and discussion STAR★Method

    The Diabetes Education Experience of Randomly Selected Patients Under the Care of Community Physicians

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    The purpose of this study was to describe the diabetes education and nutritional counseling received by patients under the active care of community physicians. The study population consisted of 440 patients with diabetes from the practices of 68 primary care physicians in eight Michigan communities. Fifty-eight percent of the sample reported having received diabetes education, and the mean number of years since the most recent education was 4.15 years. Sixty-six percent reported having seen a dietitian. Patients who had received diabetes education scored higher on a basic diabetes knowledge test (70% correct vs 60%) than patients who had not received diabetes education. From 1981 to 1991, a decline was observed in the percentage of patients who reported having received diabetes education (70% to 58%). Although patient education is an integral part of comprehensive diabetes care, too few patients are receiving it. Furthermore, diabetes education often results in less-than-optimal levels of knowledge. The situation has deteriorated over the past 10 years, and patients who are not on insulin typically are the least well served.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68590/2/10.1177_014572179402000506.pd

    MHC I Stabilizing Potential of Computer-Designed Octapeptides

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    Experimental results are presented for 180 in silico designed octapeptide sequences and their stabilizing effects on the major histocompatibility class I molecule H-2Kb. Peptide sequence design was accomplished by a combination of an ant colony optimization algorithm with artificial neural network classifiers. Experimental tests yielded nine H-2Kb stabilizing and 171 nonstabilizing peptides. 28 among the nonstabilizing octapeptides contain canonical motif residues known to be favorable for MHC I stabilization. For characterization of the area covered by stabilizing and non-stabilizing octapeptides in sequence space, we visualized the distribution of 100,603 octapeptides using a self-organizing map. The experimental results present evidence that the canonical sequence motives of the SYFPEITHI database on their own are insufficient for predicting MHC I protein stabilization
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