1,261 research outputs found
The inevitable youthfulness of known high-redshift radio galaxies
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
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.
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
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)
Belowground DNA-based techniques: untangling the network of plant root interactions
Contains fulltext :
91591.pdf (publisher's version ) (Closed access)7 p
Perception of limb orientation in the vertical plane depends on center of mass rather than inertial eigenvectors
We performed two experiments to test the hypothesis that the perception of limb orientation depends on inertial eigenvectors (
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Tandem quadruplication of HMA4 in the zinc (Zn) and cadmium (Cd) hyperaccumulator noccaea caerulescens
Zinc (Zn) and cadmium (Cd) hyperaccumulation may have evolved twice in the Brassicaceae, in Arabidopsis halleri and in the Noccaea genus. Tandem gene duplication and deregulated expression of the Zn transporter, HMA4, has previously been linked to Zn/Cd hyperaccumulation in A. halleri. Here, we tested the hypothesis that tandem duplication and deregulation of HMA4 expression also occurs in Noccaea. A Noccaea caerulescens genomic library was generated, containing 36,864 fosmid pCC1FOSTM clones with insert sizes ~20–40 kbp, and screened with a PCR-generated HMA4 genomic probe. Gene copy number within the genome was estimated through DNA fingerprinting and pooled fosmid pyrosequencing. Gene copy numbers within individual clones was determined by PCR analyses with novel locus specific primers. Entire fosmids were then sequenced individually and reads equivalent to 20-fold coverage were assembled to generate complete whole contigs. Four tandem HMA4 repeats were identified in a contiguous sequence of 101,480 bp based on sequence overlap identities. These were flanked by regions syntenous with up and downstream regions of AtHMA4 in Arabidopsis thaliana. Promoter-reporter b-glucuronidase (GUS) fusion analysis of a NcHMA4 in A. thaliana revealed deregulated expression in roots and shoots, analogous to AhHMA4 promoters, but distinct from AtHMA4 expression which localised to the root vascular tissue. This remarkable consistency in tandem duplication and deregulated expression of metal transport genes between N. caerulescens and A. halleri, which last shared a common ancestor >40 mya, provides intriguing evidence that parallel evolutionary pathways may underlie Zn/Cd hyperaccumulation in Brassicaceae
International comparison of health spending and utilization among people with complex multimorbidity.
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 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 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
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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