5,740 research outputs found
A systematic search for massive young stars in the Galaxy - the RMS survey
We have selected red MSX sources (RMS) that have the colours of massive young
stellar objects (MYSOs). Our aim is to generate a large, systematically
selected sample to address questions such as their luminosity function,
lifetimes, clustering and triggering. Other objects such as UCHIIs, PN, PPN and
AGB stars have similar IR colours and a large programme of ground-based
follow-up observations is underway to identify and eliminate these from the
sample of the red MSX sources. These include radio continuum observations,
kinematic distances, ground-based mid-IR imaging, near-IR imaging and
spectroscopy to distinguish. We report the progress of these campaigns on the
3000 candidates, with initial indications showing that a substantial fraction
are indeed massive YSOs.Comment: 3 pages, 4 figures Talk in conference: Milky Way surveys, the
structure and evolution of our Galaxy, Boston 200
Health system performance assessment in small countries: The case study of Latvia
Managing the complexity that characterizes health systems requires sophisticated performance assessment information to support the decision‐making processes of healthcare stakeholders at various levels. Accordingly, in the past few decades, many countries have designed and implemented health system performance assessment (HSPA) programmes. Literature and practice agree on the key features that performance measurement in health should have, namely, multidimensionality, evidence‐based data collection, systematic benchmarking of results, shared design, transparent disclosure, and timeliness.
Nevertheless, the specific characteristics of different countries may pose challenges in the implementation of such programmes. In the case of small countries, many of these challenges are common and related to their inherent characteristics, eg, small populations, small volumes of activity for certain treatments, and lack of benchmarks.
Through the development of the case study of Latvia, this paper aims at discussing the challenges and opportunities for assessing health system performance in a small country.
As a result, for each of the performance measurement features identified by the literature, the authors discuss the issues emerging when adopting them in Latvia and set out the potential solutions that have been designed during the development of the case study
Expandable and Rapidly Differentiating Human Induced Neural Stem Cell Lines for Multiple Tissue Engineering Applications
Limited availability of human neurons poses a significant barrier to progress in biological and preclinical studies of the human nervous system. Current stem cell-based approaches of neuron generation are still hindered by prolonged culture requirements, protocol complexity, and variability in neuronal differentiation. Here we establish stable human induced neural stem cell (hiNSC) lines through the direct reprogramming of neonatal fibroblasts and adult adipose-derived stem cells. These hiNSCs can be passaged indefinitely and cryopreserved as colonies. Independently of media composition, hiNSCs robustly differentiate into TUJ1-positive neurons within 4 days, making them ideal for innervated co-cultures. In vivo, hiNSCs migrate, engraft, and contribute to both central and peripheral nervous systems. Lastly, we demonstrate utility of hiNSCs in a 3D human brain model. This method provides a valuable interdisciplinary tool that could be used to develop drug screening applications as well as patient-specific disease models related to disorders of innervation and the brain
Single-incision vaginal approach to treat cystocele and vault prolapse with an anterior wall mesh anchored apically to the sacrospinous ligaments
Sensor Development for High Temperature Viscosity Measurement
In previous years, we have presented several results on viscosity measurements using conventional and laser ultrasound techniques [1,2,3]. These results are based on experiments conducted at room temperature. The principle[1], in essence, is to launch ultrasonic shear waves at the interface of a solid and a viscous fluid. The amplitude and phase of the reflected waves were correlated to the viscosity of the fluid.</p
Incidence of 'low-risk but not no-risk' features of cancer prior to high-risk feature occurrence: An observational cohort study in primary care.
This is the final version. Available from MDPI via the DOI in this record. Data Availability Statement: The anonymised participant data from this study are not available,
in line with the CPRD’s data security policy. CPRD code libraries are available from the authors
on request.Diagnosing cancer may be expedited by decreasing referral risk threshold. Clinical Practice Research Datalink participants (≥40 years) had a positive predictive value (PPV) ≥3% feature for breast, lung, colorectal, oesophagogastric, pancreatic, renal, bladder, prostatic, ovarian, endometrial or laryngeal cancer in 2016. The numbers of participants with features representing a 1-1.99% or 2-2.99% PPV for same cancer in the previous year were reported, alongside the time difference between meeting the ≥3% criteria and the lower threshold criteria. A total of 8616 participants had a PPV ≥3% feature, of whom 365 (4.2%) and 1147 (13.3%), respectively, met 2-2.99% and 1-1.99% criteria in the preceding year. The median time difference was 131 days (Interquartile Range (IQR) 27 to 256) for the 2-2.99% band and 179 days (IQR 58 to 289) for the 1-1.99% band. Results were heterogeneous across cancer sites. For some cancers, participants may progress from presenting lower- to higher-risk features before meeting urgent referral criteria; however, this was not usually the case. The details of specific features across multiple cancer sites will allow for a tailored approach to future reductions in referral thresholds, potentially improving the efficiency of urgent cancer referrals for the benefit both of individuals and the National Health Service (NHS).National Institute for Health ResearchNational Institute for Health Researc
Who bullies whom at a garden feeder? Interspecific agonistic interactions of small passerines during a cold winter
Interspecific agonistic interactions are important
selective factors for maintaining ecological niches of
different species, but their outcome is difficult to predict
a priori. Here, we examined the direction and intensity of
interspecific interactions in an assemblage of small passerines
at a garden feeder, focussing on three finch species
of various body sizes. We found that large and mediumsized
birds usually initiated and won agonistic interactions
with smaller species. Also, the frequency of fights increased
with decreasing differences in body size between
the participants. Finally, the probability of engaging in a
fight increased with the number of birds at the feeder
Use of a Semi-field System to Evaluate the Efficacy of Topical Repellents under user Conditions Provides a Disease Exposure free Technique Comparable with Field Data.
Before topical repellents can be employed as interventions against arthropod bites, their efficacy must be established. Currently, laboratory or field tests, using human volunteers, are the main methods used for assessing the efficacy of topical repellents. However, laboratory tests are not representative of real life conditions under which repellents are used and field-testing potentially exposes human volunteers to disease. There is, therefore, a need to develop methods to test efficacy of repellents under real life conditions while minimizing volunteer exposure to disease. A lotion-based, 15% N, N-Diethyl-3-methylbenzamide (DEET) repellent and 15% DEET in ethanol were compared to a placebo lotion in a 200 sq m (10 m x 20 m) semi-field system (SFS) against laboratory-reared Anopheles arabiensis mosquitoes and in full field settings against wild malaria vectors and nuisance-biting mosquitoes. The average percentage protection against biting mosquitoes over four hours in the SFS and field setting was determined. A Poisson regression model was then used to determine relative risk of being bitten when wearing either of these repellents compared to the placebo. Average percentage protection of the lotion-based 15% DEET repellent after four hours of mosquito collection was 82.13% (95% CI 75.94-88.82) in the semi-field experiments and 85.10% (95% CI 78.97-91.70) in the field experiments. Average percentage protection of 15% DEET in ethanol after four hours was 71.29% (CI 61.77-82.28) in the semi-field system and 88.24% (84.45-92.20) in the field. Semi-field evaluation results were comparable to full-field evaluations, indicating that such systems could be satisfactorily used in measuring efficacy of topically applied mosquito repellents, thereby avoiding risks of exposure to mosquito-borne pathogens, associated with field testing
The prognostic utility of tests of platelet function for the detection of 'aspirin resistance' in patients with established cardiovascular or cerebrovascular disease: a systematic review and economic evaluation.
BACKGROUND: The use of aspirin is well established for secondary prevention of cardiovascular disease. However, a proportion of patients suffer repeat cardiovascular events despite being prescribed aspirin treatment. It is uncertain whether or not this is due to an inherent inability of aspirin to sufficiently modify platelet activity. This report aims to investigate whether or not insufficient platelet function inhibition by aspirin ('aspirin resistance'), as defined using platelet function tests (PFTs), is linked to the occurrence of adverse clinical outcomes, and further, whether or not patients at risk of future adverse clinical events can be identified through PFTs. OBJECTIVES: To review systematically the clinical effectiveness and cost-effectiveness evidence regarding the association between PFT designation of 'aspirin resistance' and the risk of adverse clinical outcome(s) in patients prescribed aspirin therapy. To undertake exploratory model-based cost-effectiveness analysis on the use of PFTs. DATA SOURCES: Bibliographic databases (e.g. MEDLINE from inception and EMBASE from 1980), conference proceedings and ongoing trial registries up to April 2012. METHODS: Standard systematic review methods were used for identifying clinical and cost studies. A risk-of-bias assessment tool was adapted from checklists for prognostic and diagnostic studies. (Un)adjusted odds and hazard ratios for the association between 'aspirin resistance', for different PFTs, and clinical outcomes are presented; however, heterogeneity between studies precluded pooling of results. A speculative economic model of a PFT and change of therapy strategy was developed. RESULTS: One hundred and eight relevant studies using a variety of PFTs, 58 in patients on aspirin monotherapy, were analysed in detail. Results indicated that some PFTs may have some prognostic utility, i.e. a trend for more clinical events to be associated with groups classified as 'aspirin resistant'. Methodological and clinical heterogeneity prevented a quantitative summary of prognostic effect. Study-level effect sizes were generally small and absolute outcome risk was not substantially different between 'aspirin resistant' and 'aspirin sensitive' designations. No studies on the cost-effectiveness of PFTs for 'aspirin resistance' were identified. Based on assumptions of PFTs being able to accurately identify patients at high risk of clinical events and such patients benefiting from treatment modification, the economic model found that a test-treat strategy was likely to be cost-effective. However, neither assumption is currently evidence based. LIMITATIONS: Poor or incomplete reporting of studies suggests a potentially large volume of inaccessible data. Analyses were confined to studies on patients prescribed aspirin as sole antiplatelet therapy at the time of PFT. Clinical and methodological heterogeneity across studies precluded meta-analysis. Given the lack of robust data the economic modelling was speculative. CONCLUSIONS: Although evidence indicates that some PFTs may have some prognostic value, methodological and clinical heterogeneity between studies and different approaches to analyses create confusion and inconsistency in prognostic results, and prevented a quantitative summary of their prognostic effect. Protocol-driven and adequately powered primary studies are needed, using standardised methods of measurements to evaluate the prognostic ability of each test in the same population(s), and ideally presenting individual patient data. For any PFT to inform individual risk prediction, it will likely need to be considered in combination with other prognostic factors, within a prognostic model. STUDY REGISTRATION: This study is registered as PROSPERO 2012:CRD42012002151. FUNDING: The National Institute for Health Research Health Technology Assessment programme
Electronic Devices Based on Purified Carbon Nanotubes Grown By High Pressure Decomposition of Carbon Monoxide
The excellent properties of transistors, wires, and sensors made from
single-walled carbon nanotubes (SWNTs) make them promising candidates for use
in advanced nanoelectronic systems. Gas-phase growth procedures such as the
high pressure decomposition of carbon monoxide (HiPCO) method yield large
quantities of small diameter semiconducting SWNTs, which are ideal for use in
nanoelectronic circuits. As-grown HiPCO material, however, commonly contains a
large fraction of carbonaceous impurities that degrade properties of SWNT
devices. Here we demonstrate a purification, deposition, and fabrication
process that yields devices consisting of metallic and semiconducting nanotubes
with electronic characteristics vastly superior to those of circuits made from
raw HiPCO. Source-drain current measurements on the circuits as a function of
temperature and backgate voltage are used to quantify the energy gap of
semiconducting nanotubes in a field effect transistor geometry. This work
demonstrates significant progress towards the goal of producing complex
integrated circuits from bulk-grown SWNT material.Comment: 6 pages, 4 figures, to appear in Nature Material
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