1,256 research outputs found

    The inevitable youthfulness of known high-redshift radio galaxies

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    Radio galaxies can be seen out to very high redshifts, where in principle they can serve as probes of the early evolution of the Universe. Here we show that for any model of radio-galaxy evolution in which the luminosity decreases with time after an initial rapid increase (that is, essentially all reasonable models), all observable high-redshift radio-galaxies must be seen when the lobes are less than 10^7 years old. This means that high-redshift radio galaxies can be used as a high-time-resolution probe of evolution in the early Universe. Moreover, this result helps to explain many observed trends of radio-galaxy properties with redshift [(i) the `alignment effect' of optical emission along radio-jet axes, (ii) the increased distortion in radio structure, (iii) the decrease in physical sizes, (iv) the increase in radio depolarisation, and (v) the increase in dust emission] without needing to invoke explanations based on cosmology or strong evolution of the surrounding intergalactic medium with cosmic time, thereby avoiding conflict with current theories of structure formation.Comment: To appear in Nature. 4 pages, 2 colour figures available on request. Also available at http://www-astro.physics.ox.ac.uk/~km

    Individual Participant Data (IPD) Meta-analyses of Randomised Controlled Trials: Guidance on Their Use

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    Jayne Tierney and colleagues offer guidance on how to spot a well-designed and well-conducted individual participant data meta-analysis

    International comparison of spending and utilization at the end of life for hip fracture patients.

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    ObjectiveTo identify and explore differences in spending and utilization of key health services at the end of life among hip fracture patients across seven developed countries.Data sourcesIndividual-level claims data from the inpatient and outpatient health care sectors compiled by the International Collaborative on Costs, Outcomes, and Needs in Care (ICCONIC).Study designWe retrospectively analyzed utilization and spending from acute hospital care, emergency department, outpatient primary care and specialty physician visits, and outpatient drugs. Patterns of spending and utilization were compared in the last 30, 90, and 180 days across Australia, Canada, England, Germany, New Zealand, Spain, and the United States. We employed linear regression models to measure age- and sex-specific effects within and across countries. In addition, we analyzed hospital-centricity, that is, the days spent in hospital and site of death.Data collection/extraction methodsWe identified patients who sustained a hip fracture in 2016 and died within 12 months from date of admission.Principal findingsResource use, costs, and the proportion of deaths in hospital showed large variability being high in England and Spain, while low in New Zealand. Days in hospital significantly decreased with increasing age in Canada, Germany, Spain, and the United States. Hospital spending near date of death was significantly lower for women in Canada, Germany, and the United States. The age gradient and the sex effect were less pronounced in utilization and spending of emergency care, outpatient care, and drugs.ConclusionsAcross seven countries, we find important variations in end-of-life care for patients who sustained a hip fracture, with some differences explained by sex and age. Our work sheds important insights that may help ongoing health policy discussions on equity, efficiency, and reimbursement in health care systems

    Spatiotemporal Infectious Disease Modeling: A BME-SIR Approach

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    This paper is concerned with the modeling of infectious disease spread in a composite space-time domain under conditions of uncertainty. We focus on stochastic modeling that accounts for basic mechanisms of disease distribution and multi-sourced in situ uncertainties. Starting from the general formulation of population migration dynamics and the specification of transmission and recovery rates, the model studies the functional formulation of the evolution of the fractions of susceptible-infected-recovered individuals. The suggested approach is capable of: a) modeling population dynamics within and across localities, b) integrating the disease representation (i.e. susceptible-infected-recovered individuals) with observation time series at different geographical locations and other sources of information (e.g. hard and soft data, empirical relationships, secondary information), and c) generating predictions of disease spread and associated parameters in real time, while considering model and observation uncertainties. Key aspects of the proposed approach are illustrated by means of simulations (i.e. synthetic studies), and a real-world application using hand-foot-mouth disease (HFMD) data from China.J.M. Angulo and A.E. Madrid have been partially supported by grants MTM2009-13250 and MTM2012-32666 of SGPI, and P08-FQM-3834 of the Andalusian CICE, Spain. H-L Yu has been partially supported by a grant from National Science Council of Taiwan (NSC101-2628-E-002-017-MY3 and NSC102-2221-E-002-140-MY3). A. Kolovos was supported by SpaceTimeWorks, LLC. G. Christakos was supported by a Yongqian Chair Professorship (Zhejiang University, China)

    International comparison of health spending and utilization among people with complex multimorbidity.

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    OBJECTIVE: The objective of this study was to explore cross-country differences in spending and utilization across different domains of care for a multimorbid persona with heart failure and diabetes. DATA SOURCES: We used individual-level administrative claims or registry data from inpatient and outpatient health care sectors compiled by the International Collaborative on Costs, Outcomes, and Needs in Care (ICCONIC) across 11 countries: Australia, Canada, England, France, Germany, the Netherlands, New Zealand, Spain, Sweden, Switzerland, and the United States (US). DATA COLLECTION/EXTRACTION METHODS: Data collected by ICCONIC partners. STUDY DESIGN: We retrospectively analyzed age-sex standardized utilization and spending of an older person (65-90 years) hospitalized with a heart failure exacerbation and a secondary diagnosis of diabetes across five domains of care: hospital care, primary care, outpatient specialty care, post-acute rehabilitative care, and outpatient drugs. PRINCIPAL FINDINGS: Sample sizes ranged from n = 1270 in Spain to n = 21,803 in the United States. Mean age (standard deviation [SD]) ranged from 76.2 (5.6) in the Netherlands to 80.3 (6.8) in Sweden. We observed substantial variation in spending and utilization across care settings. On average, England spent 10,956perpersoninhospitalcarewhiletheUnitedStatesspent10,956 per person in hospital care while the United States spent 30,877. The United States had a shorter length of stay over the year (18.9 days) compared to France (32.9) and Germany (33.4). The United States spent more days in facility-based rehabilitative care than other countries. Australia spent 421perpersoninprimarycare,whileSpain(Aragon)spent421 per person in primary care, while Spain (Aragon) spent 1557. The United States and Canada had proportionately more visits to specialist providers than primary care providers. Across almost all sectors, the United States spent more than other countries, suggesting higher prices per unit. CONCLUSION: Across 11 countries, there is substantial variation in health care spending and utilization for a complex multimorbid persona with heart failure and diabetes. Drivers of spending vary across countries, with the United States being the most expensive country due to high prices and higher use of facility-based rehabilitative care

    Prosecute and Punish: Curbing Political and Administrative Corruption in Kenya

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    Due to the inherent difficulties in curbing corrupt practices within the public sector, several countries in sub-Saharan Africa are today engaged in what can be described as experimentation with diverse and creative strategies. These strategies range from public education and awareness, to institutional and democratic reforms, economic liberalization, and the creation of ad hoc or permanent anticorruption agencies (Robinson 1998). In some countries such agencies are established through the acts of parliaments and in some by presidential decrees (Pillay and Dorasamy 2010). Often the rationale for such agencies are twofold: to investigate claims of corruption and to prosecute the perpetrators and to demonstrate to the general public that the government is acting accountably and responsibly by trying to do something about the vice
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