2,594 research outputs found
Rapid size change associated with intra-island evolutionary radiation in extinct Caribbean "island-shrews"
Background: The Caribbean offers a unique opportunity to study evolutionary dynamics in insular mammals. However,
the recent extinction of most Caribbean non-volant mammals has obstructed evolutionary studies, and poor DNA
preservation associated with tropical environments means that very few ancient DNA sequences are available for extinct
vertebrates known from the regionâs Holocene subfossil record. The endemic Caribbean eulipotyphlan family
Nesophontidae (âisland-shrewsâ) became extinct ~ 500 years ago, and the taxonomic validity of many Nesophontes species
and their wider evolutionary dynamics remain unclear. Here we use both morphometric and palaeogenomic methods to
clarify the status and evolutionary history of Nesophontes species from Hispaniola, the second-largest Caribbean island.
Results: Principal component analysis of 65 Nesophontes mandibles from late Quaternary fossil sites across Hispaniola
identified three non-overlapping morphometric clusters, providing statistical support for the existence of three sizedifferentiated Hispaniolan Nesophontes species. We were also able to extract and sequence ancient DNA from a ~ 750-yearold specimen of Nesophontes zamicrus, the smallest non-volant Caribbean mammal, including a whole-mitochondrial
genome and partial nuclear genes. Nesophontes paramicrus (39-47 g) and N. zamicrus (~ 10 g) diverged recently during the
Middle Pleistocene (mean estimated divergence = 0.699 Ma), comparable to the youngest species splits in Eulipotyphla and
other mammal groups. Pairwise genetic distance values for N. paramicrus and N. zamicrus based on mitochondrial and
nuclear genes are low, but fall within the range of comparative pairwise data for extant eulipotyphlan species-pairs.
Conclusions: Our combined morphometric and palaeogenomic analyses provide evidence for multiple co-occurring
species and rapid body size evolution in Hispaniolan Nesophontes, in contrast to patterns of genetic and morphometric
differentiation seen in Hispaniolaâs extant non-volant land mammals. Different components of Hispaniolaâs mammal fauna
have therefore exhibited drastically different rates of morphological evolution. Morphological evolution in Nesophontes is
also rapid compared to patterns across the Eulipotyphla, and our study provides an important new example of rapid body
size change in a small-bodied insular vertebrate lineage. The Caribbean was a hotspot for evolutionary diversification as
well as preserving ancient biodiversity, and studying the surviving representatives of its mammal fauna is insufficient to
reveal the evolutionary patterns and processes that generated regional diversity
Development of a pilot plant for the removal of rhenium from molybdenum trioxide.
Reagent grade molybdenum trioxide used as a target material for the preparation of Tc-99m pharmaceuticals contains trace amounts of rhenium. A simple charcoal adsorptions process has been developed to remove rhenium selectively from molybdenum before neutron irradiation. Details are given of the design and operation of a pilot plant in which 17 kg of molybdenum trioxide was produced having a rhenium content of less than 1 x 10 -6 mu g g -1. Although contamination of the Tc-99m by inactive rhenium and 188 Re was effectively eliminated 188 Re resulting from the irradiation of tungsten impurity in the molybdenum trioxide target was still present
The iBRA (implant breast reconstruction evaluation) study: protocol for a prospective multi-centre cohort study to inform the feasibility, design and conduct of a pragmatic randomised clinical trial comparing new techniques of implant-based breast reconstruction.
BACKGROUND: Implant-based breast reconstruction (IBBR) is the most commonly performed reconstructive procedure in the UK. The introduction of techniques to augment the subpectoral pocket has revolutionised the procedure, but there is a lack of high-quality outcome data to describe the safety or effectiveness of these techniques. Randomised controlled trials (RCTs) are the best way of comparing treatments, but surgical RCTs are challenging. The iBRA (implant breast reconstruction evaluation) study aims to determine the feasibility, design and conduct of a pragmatic RCT to examine the effectiveness of approaches to IBBR. METHODS/DESIGN: The iBRA study is a trainee-led research collaborative project with four phases:Phase 1 - a national practice questionnaire (NPQ) to survey current practicePhase 2 - a multi-centre prospective cohort study of patients undergoing IBBR to evaluate the clinical and patient-reported outcomesPhase 3- an IBBR-RCT acceptability survey and qualitative work to explore patients' and surgeons' views of proposed trial designs and candidate outcomes.Phase 4 - phases 1 to 3 will inform the design and conduct of the future RCT All centres offering IBBR will be encouraged to participate by the breast and plastic surgical professional associations (Association of Breast Surgery and British Association of Plastic Reconstructive and Aesthetic Surgeons). Data collected will inform the feasibility of undertaking an RCT by defining current practice and exploring issues surrounding recruitment, selection of comparator arms, choice of primary outcome, sample size, selection criteria, trial conduct, methods of data collection and feasibility of using the trainee collaborative model to recruit patients and collect data. DISCUSSION: The preliminary work undertaken within the iBRA study will determine the feasibility, design and conduct of a definitive RCT in IBBR. It will work with the trainee collaborative to build capacity by creating an infrastructure of research-active breast and plastic surgeons which will facilitate future high-quality research that will ultimately improve outcomes for all women seeking reconstructive surgery. TRIAL REGISTRATION: ISRCTN37664281
Can Plan Recommendations Improve the Coverage Decisions of Vulnerable Populations in Health Insurance Marketplaces?
OBJECTIVE: The Affordable Care Act's marketplaces present an important opportunity for expanding coverage but consumers face enormous challenges in navigating through enrollment and re-enrollment. We tested the effectiveness of a behaviorally informed policy tool--plan recommendations--in improving marketplace decisions. STUDY SETTING: Data were gathered from a community sample of 656 lower-income, minority, rural residents of Virginia. STUDY DESIGN: We conducted an incentive-compatible, computer-based experiment using a hypothetical marketplace like the one consumers face in the federally-facilitated marketplaces, and examined their decision quality. Participants were randomly assigned to a control condition or three types of plan recommendations: social normative, physician, and government. For participants randomized to a plan recommendation condition, the plan that maximized expected earnings, and minimized total expected annual health care costs, was recommended. DATA COLLECTION: Primary data were gathered using an online choice experiment and questionnaire. PRINCIPAL FINDINGS: Plan recommendations resulted in a 21 percentage point increase in the probability of choosing the earnings maximizing plan, after controlling for participant characteristics. Two conditions, government or providers recommending the lowest cost plan, resulted in plan choices that lowered annual costs compared to marketplaces where no recommendations were made. CONCLUSIONS: As millions of adults grapple with choosing plans in marketplaces and whether to switch plans during open enrollment, it is time to consider marketplace redesigns and leverage insights from the behavioral sciences to facilitate consumers' decisions
Characterisation and expression of SPLUNC2, the human orthologue of rodent parotid secretory protein
We recently described the Palate Lung Nasal Clone (PLUNC) family of proteins as an extended group of proteins expressed in the upper airways, nose and mouth. Little is known about these proteins, but they are secreted into the airway and nasal lining fluids and saliva where, due to their structural similarity with lipopolysaccharide-binding protein and bactericidal/permeability-increasing protein, they may play a role in the innate immune defence. We now describe the generation and characterisation of novel affinity-purified antibodies to SPLUNC2, and use them to determine the expression of this, the major salivary gland PLUNC. Western blotting showed that the antibodies identified a number of distinct protein bands in saliva, whilst immunohistochemical analysis demonstrated protein expression in serous cells of the major salivary glands and in the ductal lumens as well as in cells of minor mucosal glands. Antibodies directed against distinct epitopes of the protein yielded different staining patterns in both minor and major salivary glands. Using RT-PCR of tissues from the oral cavity, coupled with EST analysis, we showed that the gene undergoes alternative splicing using two 5' non-coding exons, suggesting that the gene is regulated by alternative promoters. Comprehensive RACE analysis using salivary gland RNA as template failed to identify any additional exons. Analysis of saliva showed that SPLUNC2 is subject to N-glycosylation. Thus, our study shows that multiple SPLUNC2 isoforms are found in the oral cavity and suggest that these proteins may be differentially regulated in distinct tissues where they may function in the innate immune response
Serotonin and corticosterone rhythms in mice exposed to cigarette smoke and in patients with COPD:implication for COPD-associated neuropathogenesis
The circadian timing system controls daily rhythms of physiology and behavior, and disruption of clock function can trigger stressful life events. Daily exposure to cigarette smoke (CS) can lead to alteration in diverse biological and physiological processes. Smoking is associated with mood disorders, including depression and anxiety. Patients with chronic obstructive pulmonary disease (COPD) have abnormal circadian rhythms, reflected by daily changes in respiratory symptoms and lung function. Corticosterone (CORT) is an adrenal steroid that plays a considerable role in stress and anti-inflammatory responses. Serotonin (5-hydroxytryptamine; 5HT) is a neurohormone, which plays a role in sleep/wake regulation and affective disorders. Secretion of stress hormones (CORT and 5HT) is under the control of the circadian clock in the suprachiasmatic nucleus. Since smoking is a contributing factor in the development of COPD, we hypothesize that CS can affect circadian rhythms of CORT and 5HT secretion leading to sleep and mood disorders in smokers and patients with COPD. We measured the daily rhythms of plasma CORT and 5HT in mice following acute (3 d), sub-chronic (10 d) or chronic (6 mo) CS exposure and in plasma from non-smokers, smokers and patients with COPD. Acute and chronic CS exposure affected both the timing (peak phase) and amplitude of the daily rhythm of plasma CORT and 5HT in mice. Acute CS appeared to have subtle time-dependent effects on CORT levels but more pronounced effects on 5HT. As compared with CORT, plasma 5HT was slightly elevated in smokers but was reduced in patients with COPD. Thus, the effects of CS on plasma 5HT were consistent between mice and patients with COPD. Together, these data reveal a significant impact of CS exposure on rhythms of stress hormone secretion and subsequent detrimental effects on cognitive function, depression-like behavior, mood/anxiety and sleep quality in smokers and patients with COPD
A Vast Thin Plane of Co-rotating Dwarf Galaxies Orbiting the Andromeda Galaxy
Dwarf satellite galaxies are thought to be the remnants of the population of
primordial structures that coalesced to form giant galaxies like the Milky Way.
An early analysis noted that dwarf galaxies may not be isotropically
distributed around our Galaxy, as several are correlated with streams of HI
emission, and possibly form co-planar groups. These suspicions are supported by
recent analyses, and it has been claimed that the apparently planar
distribution of satellites is not predicted within standard cosmology, and
cannot simply represent a memory of past coherent accretion. However, other
studies dispute this conclusion. Here we report the existence (99.998%
significance) of a planar sub-group of satellites in the Andromeda galaxy,
comprising approximately 50% of the population. The structure is vast: at least
400 kpc in diameter, but also extremely thin, with a perpendicular scatter
<14.1 kpc (99% confidence). Radial velocity measurements reveal that the
satellites in this structure have the same sense of rotation about their host.
This finding shows conclusively that substantial numbers of dwarf satellite
galaxies share the same dynamical orbital properties and direction of angular
momentum, a new insight for our understanding of the origin of these most dark
matter dominated of galaxies. Intriguingly, the plane we identify is
approximately aligned with the pole of the Milky Way's disk and is co-planar
with the Milky Way to Andromeda position vector. The existence of such
extensive coherent kinematic structures within the halos of massive galaxies is
a fact that must be explained within the framework of galaxy formation and
cosmology.Comment: Published in the 3rd Jan 2013 issue of Nature. 19 pages, 4 figures, 1
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Organising a collaborative online hackathon for cutting-edge climate research
The 2021 Met Office Climate Data Challenge hackathon series provided a valuable opportunity to learn best practice from the experience of running online hackathons uniquely characterised by the challenges faced by climate data science in the wake of the COVID-19 pandemic. In particular, the University of Bristol CMIP6 Data Hackathon with over 100 participants from the United Kingdom highlights the advantages of participating in such events as well as lessons learned. A suggested methodology to structure, plan, promote and ensure longevity of the hackathon outputs is described ensuring smoother running of future events
Cost-effectiveness of financial incentives to promote adherence to depot antipsychotic medication: economic evaluation of a cluster-randomised controlled trial
Background: Offering a modest financial incentive to people with psychosis can promote adherence to depot antipsychotic medication, but the cost-effectiveness of this approach has not been examined. Methods: Economic evaluation within a pragmatic cluster-randomised controlled trial. 141 patients under the care of 73 teams (clusters) were randomised to intervention or control; 138 patients with diagnoses of schizophrenia, schizo-affective disorder or bipolar disorder participated. Intervention participants received ÂŁ15 per depot injection over 12 months, additional to usual acute, mental and community primary health services. The control group received usual health services. Main outcome measures: incremental cost per 20% increase in adherence to depot antipsychotic medication; incremental cost of âgoodâ adherence (defined as taking at least 95% of the prescribed number of depot medications over the intervention period). Findings: Economic and outcome data for baseline and 12-month follow-up were available for 117 participants. The adjusted difference in adherence between groups was 12.2% (73.4% control vs. 85.6% intervention); the adjusted costs difference was ÂŁ598 (95% CI -ÂŁ4 533, ÂŁ5 730). The extra cost per patient to increase adherence to depot medications by 20% was ÂŁ982 (95% CI -ÂŁ8 020, ÂŁ14 000). The extra cost per patient of achieving 'good' adherence was ÂŁ2 950 (CI -ÂŁ19 400, ÂŁ27 800). Probability of cost-effectiveness exceeded 97.5%at willingness-to-pay values of ÂŁ14 000 for a 20% increase in adherence and ÂŁ27 800 for good adherence. Interpretation: Offering a modest financial incentive to people with psychosis is cost-effective in promoting adherence to depot antipsychotic medication. Direct healthcare costs (including costs of the financial incentive) are unlikely to be increased by this intervention. Trial Registration: ISRCTN.com 7776928
A randomized open-label trial on the use of budesonide/formoterol (SymbicortÂź) as an alternative reliever medication for mild to moderate asthmatic attacks
BACKGROUND
Conventionally, a nebulized short-acting ÎČ-2 agonist like salbutamol is often used as the reliever in acute exacerbations of asthma. However, recent worldwide respiratory outbreaks discourage routine use of nebulization. Previous studies have shown that combined budesonide/formoterol (SymbicortÂź, AstraZeneca) is effective as both a maintenance and reliever anti-asthmatic medication.
METHODS
We performed a randomized, open-label study from March until August 2011 to compare the bronchodilatory effects of SymbicortÂź vs. nebulized salbutamol in acute exacerbation of mild to moderate asthmatic attack in an emergency department. Initial objective parameters measured include the oxygen saturation, peak expiratory flow rate (PEFR) and respiratory rate. During clinical reassessment, subjective parameters [i.e., Visual Analog Scale (VAS) and 5-point Likert scale of breathlessness] and the second reading of the objective parameters were measured. For the 5-point Likert scale, the patients were asked to describe their symptom relief as 1, much worse; 2, a little worse; 3, no change; 4, a little better; 5, much better.
RESULTS
Out of the total of 32 patients enrolled, 17 patients (53%) were randomized to receive nebulized salbutamol and 15 (47%) to receive SymbicortÂź. For both treatment arms, by using paired t- and Wilcoxon signed rank tests, it was shown that there were statistically significant improvements in oxygen saturation, PEFR and respiratory rate within the individual treatment groups (pre- vs. post-treatment). Comparing the effects of SymbicortÂź vs. nebulized salbutamol, the average improvement of oxygen saturation was 1% in both treatment arms (p = 0.464), PEFR 78.67 l/min vs. 89.41 l/min, respectively (p = 0.507), and respiratory rate 2/min vs. 2/min (p = 0.890). For subjective evaluation, all patients reported improvement in the VAS (average 2.45 cm vs. 2.20 cm), respectively (p = 0.765). All patients in both treatment arms reported either "a little better" or "much better" on the 5-point Likert scale, with none reporting "no change" or getting worse.
CONCLUSION
This study suggests that there is no statistical difference between using SymbicortÂź vs. nebulized salbutamol as the reliever for the first 15 min post-intervention
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