1,221 research outputs found

    Pulsar Results with the Fermi Large Area Telescope

    Full text link
    The launch of the Fermi Gamma-ray Space Telescope has heralded a new era in the study of gamma-ray pulsars. The population of confirmed gamma-ray pulsars has gone from 6-7 to more than 60, and the superb sensitivity of the Large Area Telescope (LAT) on Fermi has allowed the detailed study of their spectra and light curves. Twenty-four of these pulsars were discovered in blind searches of the gamma-ray data, and twenty-one of these are, at present, radio quiet, despite deep radio follow-up observations. In addition, millisecond pulsars have been confirmed as a class of gamma-ray emitters, both individually and collectively in globular clusters. Recently, radio searches in the direction of LAT sources with no likely counterparts have been highly productive, leading to the discovery of a large number of new millisecond pulsars. Taken together, these discoveries promise a great improvement in the understanding of the gamma-ray emission properties and Galactic population of pulsars. We summarize some of the results stemming from these newly-detected pulsars and their timing and multi-wavelength follow-up observations.Comment: 21 pages, 9 figures, to appear in Proceedings of ICREA Workshop on The High-Energy Emission from Pulsars and their Systems, Sant Cugat, Spain, 2010 April 12-16 (Springer

    Trends in mortality by labour market position around retirement ages in three European countries with different welfare regimes

    Get PDF
    <p>Objectives: In the face of economic downturn and increasing life expectancy, many industrial nations are adopting a policy of postponing the retirement age. However, questions still remain around the consequence of working longer into old age. We examine mortality by work status around retirement ages in countries with different welfare regimes; Finland (social democratic), Turin (Italy; conservative), and England and Wales (liberal).</p> <p>Methods: Death rates and rate ratios (RRs) (reference rates = ‘in-work’), 1970 s–2000 s, were estimated for those aged 45–64 years using the England and Wales longitudinal study, Turin longitudinal study, and the Finnish linked register study.</p> <p>Results: Mortality of the not-in-work was consistently higher than the in-work. Death rates for the not-in-work were lowest in Turin and highest in Finland. Rate ratios were smallest in Turin (RR men 1972–76 1.73; 2002–06 1.63; women 1.22; 1.68) and largest in Finland (RR men 1991–95 3.03; 2001–05 3.80; women 3.62; 4.11). Unlike RRs for men, RRs for women increased in every country (greatest in Finland).</p> <p>Conclusions: These findings signal that overall, employment in later life is associated with lower mortality, regardless of welfare regime.</p&gt

    A Chinese immigrant paradox? Low coronary heart disease incidence but higher short?term mortality in western?dwelling Chinese immigrants: a systematic review and meta?analysis.

    Get PDF
    Background-—Chinese form a large proportion of the immigrant population in Western countries. There is evidence that Chineseimmigrants experience an increased risk of coronary heart disease (CHD) after immigration in part due to cultural habits andacculturation. This is the first systematic review and meta-analysis that aims to examine the risk of CHD in people of Chineseethnicity living in Western countries, in comparison with whites and another major immigrant group, South Asians.Methods and Results-—Literature on the incidence, mortality, and prognosis of CHD among Chinese living in Western countrieswas searched systematically in any language using 6 electronic databases up to December 2014. Based on the meta-analysis,Chinese had lower incidence of CHD compared with whites (odds ratio 0.29; 95% CI: 0.24–0.34) and South Asians (odds ratio 0.37;95% CI: 0.24–0.57) but higher short-term mortality after first hospitalization for acute myocardial infarction compared with whites(odds ratio 1.34; 95% CI, 1.04–1.73) and South Asians (odds ratio 1.82; 95% 1.33–2.50). There was no significant differencebetween Chinese immigrants and whites in long-term outcomes (mortality and recurrent events) after acute myocardial infarction.Conclusions-—These findings provide an important focus for resource planning to enhance early secondary prevention of CHD toimprove short-term survival outcomes among Western-dwelling Chinese immigrants

    Associations between respiratory symptoms, lung function and gastro-oesophageal reflux symptoms in a population-based birth cohort

    Get PDF
    BACKGROUND: Several studies have reported an association between asthma and gastro-oesophageal reflux, but it is unclear which condition develops first. The role of obesity in mediating this association is also unclear. We explored the associations between respiratory symptoms, lung function, and gastro-oesophageal reflux symptoms in a birth cohort of approximately 1000 individuals. METHODS: Information on respiratory symptoms, asthma, atopy, lung function and airway responsiveness was obtained at multiple assessments from childhood to adulthood in an unselected birth cohort of 1037 individuals followed to age 26. Symptoms of gastro-oesophageal reflux and irritable bowel syndrome were recorded at age 26. RESULTS: Heartburn and acid regurgitation symptoms that were at least "moderately bothersome" at age 26 were significantly associated with asthma (odds ratio = 3.2; 95% confidence interval = 1.6–6.4), wheeze (OR = 3.5; 95% CI = 1.7–7.2), and nocturnal cough (OR = 4.3; 95% CI = 2.1–8.7) independently of body mass index. In women reflux symptoms were also associated with airflow obstruction and a bronchodilator response to salbutamol. Persistent wheezing since childhood, persistence of asthma since teenage years, and airway hyperresponsiveness since age 11 were associated with a significantly increased risk of heartburn and acid regurgitation at age 26. There was no association between irritable bowel syndrome and respiratory symptoms. CONCLUSION: Reflux symptoms are associated with respiratory symptoms in young adults independently of body mass index. The mechanism of these associations remains unclear

    A cost-effectiveness analysis of a hydration response technology dressing in the treatment of venous leg ulcers in the UK

    Get PDF
    Introduction: Venous leg ulceration causes significant pain and suffering for patients, additionally it places considerable financial and service burden on the National Health Service (NHS). A large proportion of venous leg ulceration do not heal within the standard time frames of 16 – 24 weeks, resulting in static wounds which commonly have issues with increasing exudate production. Static wounds can have significant negative impact on the patients quality of life, the wound bed and periwound skin, increased risk of infection all of which results in delayed wound healing and increased health service costs. As the NHS continues to face times of austerity, services need to find solutions to be able to reduce cost and release nursing time whilst maintaining standards of care. Cutimed® Sorbion® Sachet S is a treatment option for the management of patients with a venous leg ulceration. The objective of this study was to provide an update of the health economic analysis of Cutimed® Sorbion® Sachet S in comparison to relevant comparators in the UK with current cost data. Methods: Cutimed® Sorbion® Sachet S was compared against Zetuvit Plus, DryMax extra, KerraMax Care and Eclypse from a cost effectiveness perspective. Clinical data were derived from literature and expert opinion. Cost input was utilized based on publicly available data and literature. The average patient in the model is assumed to be 65 years with a diagnosed venous leg ulcer. It is assumed that patients in the different treatment arms have the same background mortality, hence the endpoint mortality is not included in the model. The analysis is based on a deterministic Markov model derived from Harding et al. with weekly cycles. The following assumptions are made: First, all patients start in a static health state with a non-healed but non-progressing venous leg ulcer. It is assumed in the model that patients can transition to a deteriorating health state where a wound is improving or the wound could progress. Additionally, venous leg ulcers could be healed from a progressed wound (i.e. improved wound), they could develop into a severe wound with complications (infections) to be treated in hospitals. The time frame for the analysis was fixed for one year and no re-occurence after healing was assumed to happen. Results: The cost-effectiveness analysis demonstrates health economic dominance of Cutimed® Sorbion® Sachet S being more effective and cost-saving against all analysed comparators. When using literature-based input values the incrementally higher healing rates for Cutimed® Sorbion® Sachet S are 11.04 months (versus Zetuvit Plus), 29.04 months (versus DryMax extra), 1.68 months (versus KerraMax Care) and 11.04 months (versus Eclypse). Cost savings per patient were 37.60£ (versus Zetuvit Plus), 171.68£ (versus DryMax extra), 3.13£ (versus KerraMax Care) and 43.63£ (versus Eclypse). Clinical benefits and cost savings are increasing when real life practice assumptions based on expert opinion are included. Conclusions: Based on the underlying health economic model, Cutimed® Sorbion® Sachet S is more effective and less costly than other comparative products in venous leg ulcers in the UK

    X-ray emission from isolated neutron stars

    Full text link
    X-ray emission is a common feature of all varieties of isolated neutron stars (INS) and, thanks to the advent of sensitive instruments with good spectroscopic, timing, and imaging capabilities, X-ray observations have become an essential tool in the study of these objects. Non-thermal X-rays from young, energetic radio pulsars have been detected since the beginning of X-ray astronomy, and the long-sought thermal emission from cooling neutron star's surfaces can now be studied in detail in many pulsars spanning different ages, magnetic fields, and, possibly, surface compositions. In addition, other different manifestations of INS have been discovered with X-ray observations. These new classes of high-energy sources, comprising the nearby X-ray Dim Isolated Neutron Stars, the Central Compact Objects in supernova remnants, the Anomalous X-ray Pulsars, and the Soft Gamma-ray Repeaters, now add up to several tens of confirmed members, plus many candidates, and allow us to study a variety of phenomena unobservable in "standard'' radio pulsars.Comment: Chapter to be published in the book of proceedings of the 1st Sant Cugat Forum on Astrophysics, "ICREA Workshop on the high-energy emission from pulsars and their systems", held in April, 201

    The C-Terminal Domain of the Arabinosyltransferase Mycobacterium tuberculosis EmbC Is a Lectin-Like Carbohydrate Binding Module

    Get PDF
    The D-arabinan-containing polymers arabinogalactan (AG) and lipoarabinomannan (LAM) are essential components of the unique cell envelope of the pathogen Mycobacterium tuberculosis. Biosynthesis of AG and LAM involves a series of membrane-embedded arabinofuranosyl (Araf) transferases whose structures are largely uncharacterised, despite the fact that several of them are pharmacological targets of ethambutol, a frontline drug in tuberculosis therapy. Herein, we present the crystal structure of the C-terminal hydrophilic domain of the ethambutol-sensitive Araf transferase M. tuberculosis EmbC, which is essential for LAM synthesis. The structure of the C-terminal domain of EmbC (EmbCCT) encompasses two sub-domains of different folds, of which subdomain II shows distinct similarity to lectin-like carbohydrate-binding modules (CBM). Co-crystallisation with a cell wall-derived di-arabinoside acceptor analogue and structural comparison with ligand-bound CBMs suggest that EmbCCT contains two separate carbohydrate binding sites, associated with subdomains I and II, respectively. Single-residue substitution of conserved tryptophan residues (Trp868, Trp985) at these respective sites inhibited EmbC-catalysed extension of LAM. The same substitutions differentially abrogated binding of di- and penta-arabinofuranoside acceptor analogues to EmbCCT, linking the loss of activity to compromised acceptor substrate binding, indicating the presence of two separate carbohydrate binding sites, and demonstrating that subdomain II indeed functions as a carbohydrate-binding module. This work provides the first step towards unravelling the structure and function of a GT-C-type glycosyltransferase that is essential in M. tuberculosis. Author Summary Top Tuberculosis (TB), an infectious disease caused by the bacillus Mycobacterium tuberculosis, burdens large swaths of the world population. Treatment of active TB typically requires administration of an antibiotic cocktail over several months that includes the drug ethambutol. This front line compound inhibits a set of arabinosyltransferase enzymes, called EmbA, EmbB and EmbC, which are critical for the synthesis of arabinan, a vital polysaccharide in the pathogen's unique cell envelope. How precisely ethambutol inhibits arabinosyltransferase activity is not clear, in part because structural information of its pharmacological targets has been elusive. Here, we report the high-resolution structure of the C-terminal domain of the ethambutol-target EmbC, a 390-amino acid fragment responsible for acceptor substrate recognition. Combining the X-ray crystallographic analysis with structural comparisons, site-directed mutagenesis, activity and ligand binding assays, we identified two regions in the C-terminal domain of EmbC that are capable of binding acceptor substrate mimics and are critical for activity of the full-length enzyme. Our results begin to define structure-function relationships in a family of structurally uncharacterised membrane-embedded glycosyltransferases, which are an important target for tuberculosis therapy
    • …
    corecore