652 research outputs found

    New Limits to the Infrared Background: Bounds on Radiative Neutrino Decay and on Contributions of Very Massive Objects to the Dark Matter Problem

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    From considering the effect of γ-γ interactions on recently observed TeV gamma-ray spectra, improved limits are set to the density of extragalactic infrared photons which are robust and essentially model independent. The resulting limits are more than an order of magnitude more restrictive than direct observations in the 0.025–0.3 eV regime. These limits are used to improve constraints on radiative neutrino decay in the mass range above 0.05 eV and to rule out very massive objects as providing the dark matter needed to explain galaxy rotation curves. Lower bounds on the maximum distance which TeV gamma rays may probe are also derived

    Constructing seasonally adjusted data with time-varying confidence intervals

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    Seasonal adjustment methods transform observed time series data into estimated data, where these estimated data are constructed such that they show no or almost no seasonal variation. An advantage of model-based methods is that these can provide confidence intervals around the seasonally adjusted data. One particularly useful time series model for seasonal adjustment is the basic structural time series [BSM] model. The usual premise of the BSM is that the variance of each of the components is constant. In this paper we address the possibility that the variance of the trend component in a macro-economic time series in some way depends on the business cycle. One reason for doing so is that one can expect that there is more uncertainty in recession periods. We extend the BSM by allowing for a business-cycle dependent variance in the level equation. Next we show how this affects the confidence intervals of seasonally adjusted data. We apply our extended BSM to monthly US unemployment and we show that the estimated confidence intervals for seasonally adjusted unemployment change with past changes in the oil price

    Short-term effects of salpingectomy during laparoscopic hysterectomy on ovarian reserve: a pilot randomized controlled trial

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    OBJECTIVE: To examine the short-term effects of salpingectomy during laparoscopic hysterectomy on ovarian reserve when ovarian preservation is planned in view of determining the feasibility of conducting the study on a larger scale. DESIGN: Pilot randomized controlled trial. SETTING: Tertiary care, academic medical center. PATIENT(S): Thirty premenopausal women aged 18 to 45 years undergoing laparoscopic hysterectomy with ovarian preservation for benign indications from April 2012 to September 2012. INTERVENTION(S): Bilateral salpingectomy (n = 15) versus no salpingectomy (n = 15) at the time of laparoscopic hysterectomy with ovarian preservation. MAIN OUTCOME MEASURE(S): AntimĂŒllerian hormone (AMH) measured preoperatively, at 4 to 6 weeks postoperatively, and at 3 months postoperatively, with operative time and estimated blood loss abstracted from the medical records. RESULT(S): The mean AMH levels were not statistically significantly different at baseline (2.26 vs. 2.25 ng/ml), 4 to 6 weeks postoperatively (1.03 vs. 1.25 ng/ml), or 3 months postoperatively (1.86 vs. 1.82 ng/ml) among women with salpingectomy versus no salpingectomy, respectively. There was also no statistically significant temporal change in the mean AMH level from baseline to 3 months postoperatively (-0.07 vs. -0.08 ng/ml) between the two groups. No difference in operative time (116 vs. 115 minutes) or estimated blood loss (70 vs. 91 mL) was observed. CONCLUSION(S): Salpingectomy at the time of laparoscopic hysterectomy with ovarian preservation is a safe procedure that does not appear to have any short-term deleterious effects on ovarian reserve, as measured by AMH level. Conducting a trial of this nature that is adequately powered with long-term follow-up evaluation would be feasible and is required to definitively confirm these results

    Framework, principles and recommendations for utilising participatory methodologies in the co-creation and evaluation of public health interventions

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    Background: Due to the chronic disease burden on society, there is a need for preventive public health interventions to stimulate society towards a healthier lifestyle. To deal with the complex variability between individual lifestyles and settings, collaborating with end-users to develop interventions tailored to their unique circumstances has been suggested as a potential way to improve effectiveness and adherence. Co-creation of public health interventions using participatory methodologies has shown promise but lacks a framework to make this process systematic. The aim of this paper was to identify and set key principles and recommendations for systematically applying participatory methodologies to co-create and evaluate public health interventions. Methods: These principles and recommendations were derived using an iterative reflection process, combining key learning from published literature in addition to critical reflection on three case studies conducted by research groups in three European institutions, all of whom have expertise in co-creating public health interventions using different participatory methodologies. Results: Key principles and recommendations for using participatory methodologies in public health intervention co-creation are presented for the stages of: Planning (framing the aim of the study and identifying the appropriate sampling strategy); Conducting (defining the procedure, in addition to manifesting ownership); Evaluating (the process and the effectiveness) and Reporting (providing guidelines to report the findings). Three scaling models are proposed to demonstrate how to scale locally developed interventions to a population level. Conclusions: These recommendations aim to facilitate public health intervention co-creation and evaluation utilising participatory methodologies by ensuring the process is systematic and reproducible

    Socially optimal contribution rate and cap in a proportional (DC) pension system

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    In our model, the government operates a mandatory proportional (DC) pension system to substitute for the low life-cycle savings of the lower-paid myopic workers, while maintaining the incentives of the higher-paid far-sighted ones in contributing to the system. The introduction of an appropriate cap on pension contribution (or its base)—excluding the earnings above the cap from the contribution base—raises the optimal contribution rate, helping more the lower-paid myopic workers and reserving enough room for the saving of higher-paid far-sighted ones. The social welfare is almost independent of the cap in a relatively wide interval but the maximal welfare is higher than the capless welfare by 0.3–4.5 %.info:eu-repo/semantics/publishedVersio

    Searching for gravitational waves from known pulsars

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    We present upper limits on the amplitude of gravitational waves from 28 isolated pulsars using data from the second science run of LIGO. The results are also expressed as a constraint on the pulsars' equatorial ellipticities. We discuss a new way of presenting such ellipticity upper limits that takes account of the uncertainties of the pulsar moment of inertia. We also extend our previous method to search for known pulsars in binary systems, of which there are about 80 in the sensitive frequency range of LIGO and GEO 600.Comment: Accepted by CQG for the proceeding of GWDAW9, 7 pages, 2 figure

    Search for Gravitational Waves from Primordial Black Hole Binary Coalescences in the Galactic Halo

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    We use data from the second science run of the LIGO gravitational-wave detectors to search for the gravitational waves from primordial black hole (PBH) binary coalescence with component masses in the range 0.2--1.0M⊙1.0 M_\odot. The analysis requires a signal to be found in the data from both LIGO observatories, according to a set of coincidence criteria. No inspiral signals were found. Assuming a spherical halo with core radius 5 kpc extending to 50 kpc containing non-spinning black holes with masses in the range 0.2--1.0M⊙1.0 M_\odot, we place an observational upper limit on the rate of PBH coalescence of 63 per year per Milky Way halo (MWH) with 90% confidence.Comment: 7 pages, 4 figures, to be submitted to Phys. Rev.

    On the Action of Methotrexate and 6-Mercaptopurine on M. avium Subspecies paratuberculosis

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    BACKGROUND: Clinical improvement in inflammatory bowel disease (IBD) treated with methotrexate and 6-mercaptopurine (6-MP) is associated with a decrease in pro-inflammatory cytokines. This has been presumed to indicate the mechanism of action of methotrexate and 6-MP. Although controversial, there are increasingly compelling data that Mycobacterium avium subspecies paratuberculosis (MAP) may be an etiological agent in some or all of IBD. We hypothesized that the clinical efficacy of methotrexate and 6-MP in IBD may be to simply inhibit the growth of MAP. METHODOLOGY: The effect on MAP growth kinetics by methotrexate and 6-MP were evaluated in cell culture of two strains each of MAP and M. avium using a radiometric ((14)CO(2) BACTECÂź) detection system that quantifies mycobacterial growth as arbitrary “growth index units” (GI). Efficacy data are presented as “percent decrease in cumulative GI” (% −ΔcGI). PRINCIPAL FINDINGS: The positive control antibiotic (clarithromycin) has ≄85% −ΔcGI at a concentration of 0.5 ”g/ml. The negative control (ampicillin) has minimal inhibition at 64 ”g/ml. MAP ATCC 19698 shows ≄80% −ΔcGI for both agents by 4 ”g/ml. With the other three isolates, although more effective than ampicillin, 6-MP is consistently less effective than methotrexate. CONCLUSIONS: We show that methotrexate and 6-MP inhibit MAP growth in vitro. Each of the four isolates manifests different % −ΔcGI. These data are compatible with the hypothesis that the clinical improvement in patients with IBD treated with methotrexate and 6-MP could be due to treating a MAP infection. The decrease in pro-inflammatory cytokines, thought to be the primary mechanism of action, may simply be a normal, secondary, physiological response. We conclude that henceforth, in clinical studies that evaluate the effect of anti-MAP agents in IBD, the use of methotrexate and 6-MP should be excluded from any control groups
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