2,311 research outputs found
Searches for Higgs bosons in e+e- collisions at centre-of-mass energies up to 209GeV
A preliminary search for Higgs bosons is performed in the data collected by ALEPH in 2000
Cumulative luminosity functions of the X-ray point source population in M31
We present preliminary results from a detailed analysis of the X-ray point
sources in the XMM-Newton survey of M31. These sources are expected to be
mostly X-ray binaries. We have so far studied 225 of the 535 sources found by
automated source detection. Only sources which were present in all three EPIC
images were considered. X-ray binaries are identified by their energy spectrum
and power density spectrum. Unlike in other surveys we have obtained source
luminosities from freely fit emission models. We present uncorrected luminosity
functions of the sources analysed so far.Comment: 2 pages, 1 figure. To appear in proceedings of IAUS23
XMM-Newton reveals ~100 new LMXBs in M31 from variability studies
We have conducted a survey of X-ray sources in XMM-Newton observations of
M31, examining their power density spectra (PDS) and spectral energy
distributions (SEDs). Our automated source detection yielded 535 good X-ray
sources; to date, we have studied 225 of them. In particular, we examined the
PDS because low mass X-ray binaries (LMXBs) exhibit two distinctive types of
PDS. At low accretion rates, the PDS is characterised by a broken power law,
with the spectral index changing from ~0 to ~1 at some frequency in the range
\~0.01--1 Hz; we refer to such PDS as Type A. At higher accretion rates, the
PDS is described by a simple power law; we call these PDS Type B. Of the 225
sources studied to date, 75 exhibit Type A variability, and are almost
certainly LMXBs, while 6 show Type B but not Type A, and are likely LMXBs. Of
these 81 candidate LMXBs, 71 are newly identified in this survey; furthermore,
they are mostly found near the centre of M31. Furthermore, most of the X-ray
population in the disc are associated with the spiral arms, making them likely
high mass X-ray binaries (HMXBs). In general these HMXBs do not exhibit Type A
variability, while many central X-ray sources (LMXBs) in the same luminosity
range do. Hence the PDS may distinguish between LMXBs and HMXBs in this
luminosity range.Comment: 4 pages, 2 figures. To appear in proceedings of IAUS230: "Populations
of High Energy Sources in Galaxies", 14-19 August 2005, Dublin, Eds E.J.A.
Meurs and G. Fabbian
Rehabilitation in chronic respiratory diseases: In-hospital and post-exacerbation pulmonary rehabilitation: Peri-exacerbation pulmonary rehabilitation
Exacerbations of chronic obstructive pulmonary disease (COPD) that require hospitalization are important events for patients. Functional impairment and skeletal muscle dysfunction can increase the risk of hospitalization and readmission, independent of lung function. In addition, once a patient is admitted, multiple factors can lead to worsening outcome including immobility, systemic inflammation and nutritional depletion. These nonâpulmonary factors are potentially amenable to exercise therapy, as part of pulmonary rehabilitation (PR). Periâexacerbation PR has an important role in the management of exacerbations of COPD. In this review, we explore how functional limitation and skeletal muscle dysfunction affect patients having a severe exacerbation of COPD, the systemic impact of hospitalization on patients including potential aetiologies and the role of PR around the time of an exacerbation. This includes rehabilitation during the inpatient phase, postâexacerbation rehabilitation and rehabilitation bridging hospital discharge. We also describe potential future developments in periâexacerbation PR
Opioid prescribing for acute postoperative pain : an overview of systematic reviews related to two consensus statements relevant at patient, prescriber, system and public health levels
Peer reviewedPublisher PD
The neural correlates of regulating positive and negative emotions in medication-free major depression
Depressive cognitive schemas play an important role in the emergence and persistence of major depressive disorder (MDD). The current study adapted emotion regulation techniques to reflect elements of cognitive behavioural therapy (CBT) and related psychotherapies to delineate neurocognitive abnormalities associated with modulating the negative cognitive style in MDD. Nineteen non-medicated patients with MDD and 19 matched controls reduced negative or enhanced positive feelings elicited by emotional scenes while undergoing functional magnetic resonance imaging. Although both groups showed significant emotion regulation success as measured by subjective ratings of affect, the controls were significantly better at modulating both negative and positive emotion. Both groups recruited regions of dorsolateral prefrontal cortex and ventrolateral prefrontal cortex (VLPFC) when regulating negative emotions. Only in controls was this accompanied by reduced activity in sensory cortices and amygdala. Similarly, both groups showed enhanced activity in VLPFC and ventral striatum when enhancing positive affect; however, only in controls was ventral striatum activity correlated with regulation efficacy. The results suggest that depression is associated with both a reduced capacity to achieve relief from negative affect despite recruitment of ventral and dorsal prefrontal cortical regions implicated in emotion regulation, coupled with a disconnect between activity in reward-related regions and subjective positive affect
Single maintenance and reliever therapy (SMART) of asthma: a critical appraisal
The use of a combination inhaler containing budesonide and formoterol as both maintenance and quick relief therapy (SMART) has been recommended as an improved method of using inhaled corticosteroid/long-acting ÎČ agonist (ICS/LABA) therapy. Published double-blind trials show that budesonide/formoterol therapy delivered in SMART fashion achieves better asthma outcomes than budesonide monotherapy or lower doses of budesonide/formoterol therapy delivered in constant dosage. Attempts to compare budesonide/formoterol SMART therapy with regular combination ICS/LABA dosing using other compounds have been confounded by a lack of blinding and unspecified dose adjustment strategies. The asthma control outcomes in SMART-treated patients are poor; it has been reported that only 17.1% of SMART-treated patients are controlled. In seven trials of 6â12â
months duration, patients using SMART have used quick reliever daily (weighted average 0.92 inhalations/day), have awakened with asthma symptoms once every 7â10â
days (weighted average 11.5% of nights), have suffered asthma symptoms more than half of days (weighted average 54.0% of days) and have had a severe exacerbation rate of one in five patients per year (weighted average 0.22 severe exacerbations/patient/year). These poor outcomes may reflect the recruitment of a skewed patient population. Although improvement from baseline has been attributed to these patients receiving additional ICS therapy at pivotal times, electronic monitoring has not been used to test this hypothesis nor the equally plausible hypothesis that patients who are non-compliant with maintenance medication have used budesonide/formoterol as needed for self-treatment of exacerbations. Although the long-term consequences of SMART therapy have not been studied, its use over 1â
year has been associated with significant increases in sputum and biopsy eosinophilia. At present, there is no evidence that better asthma treatment outcomes can be obtained by moment-to-moment symptom-driven use of ICS/LABA therapy than conventional physician-monitored and adjusted ICS/LABA therapy
Spinal cord stimulation for predominant low back pain in failed back surgery syndrome: study protocol for an international multicenter randomized controlled trial (PROMISE study)
This is the final version of the article. Available from the publisher via the DOI in this record.BACKGROUND: Although results of case series support the use of spinal cord stimulation in failed back surgery syndrome patients with predominant low back pain, no confirmatory randomized controlled trial has been undertaken in this patient group to date. PROMISE is a multicenter, prospective, randomized, open-label, parallel-group study designed to compare the clinical effectiveness of spinal cord stimulation plus optimal medical management with optimal medical management alone in patients with failed back surgery syndrome and predominant low back pain. METHOD/DESIGN: Patients will be recruited in approximately 30 centers across Canada, Europe, and the United States. Eligible patients with low back pain exceeding leg pain and an average Numeric Pain Rating Scale score â„5 for low back pain will be randomized 1:1 to spinal cord stimulation plus optimal medical management or to optimal medical management alone. The investigators will tailor individual optimal medical management treatment plans to their patients. Excluded from study treatments are intrathecal drug delivery, peripheral nerve stimulation, back surgery related to the original back pain complaint, and experimental therapies. Patients randomized to the spinal cord stimulation group will undergo trial stimulation, and if they achieve adequate low back pain relief a neurostimulation system using the SpecifyÂź 5-6-5 multi-column lead (Medtronic Inc., Minneapolis, MN, USA) will be implanted to capture low back pain preferentially in these patients. Outcome assessment will occur at baseline (pre-randomization) and at 1, 3, 6, 9, 12, 18, and 24Â months post randomization. After the 6-month visit, patients can change treatment to that received by the other randomized group. The primary outcome is the proportion of patients with â„50% reduction in low back pain at the 6-month visit. Additional outcomes include changes in low back and leg pain, functional disability, health-related quality of life, return to work, healthcare utilization including medication usage, and patient satisfaction. Data on adverse events will be collected. The primary analysis will follow the intention-to-treat principle. Healthcare use data will be used to assess costs and long-term cost-effectiveness. DISCUSSION: Recruitment began in January 2013 and will continue until 2016. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01697358 (http://www.clinicaltrials.gov).The study is funded by Medtronic In
The Redox Cofactor F-420 Protects Mycobacteria from Diverse Antimicrobial Compounds and Mediates a Reductive Detoxification System
A defining feature of mycobacterial redox metabolism is the use of an unusual deazaflavin cofactor, F420. This cofactor enhances the persistence of environmental and pathogenic mycobacteria, including after antimicrobial treatment, although the molecular basis for this remains to be understood. In this work, we explored our hypothesis that F420 enhances persistence by serving as a cofactor in antimicrobial-detoxifying enzymes. To test this, we performed a series of phenotypic, biochemical, and analytical chemistry studies in relation to the model soil bacterium Mycobacterium smegmatis. Mutant strains unable to synthesize or reduce F420 were found to be more susceptible to a wide range of antibiotic and xenobiotic compounds. Compounds from three classes of antimicrobial compounds traditionally resisted by mycobacteria inhibited the growth of F420 mutant strains at subnanomolar concentrations, namely, furanocoumarins (e.g., methoxsalen), arylmethanes (e.g., malachite green), and quinone analogues (e.g., menadione). We demonstrated that promiscuous F420H2-dependent reductases directly reduce these compounds by a mechanism consistent with hydride transfer. Moreover, M. smegmatis strains unable to make F420H2 lost the capacity to reduce and detoxify representatives of the furanocoumarin and arylmethane compound classes in whole-cell assays. In contrast, mutant strains were only slightly more susceptible to clinical antimycobacterials, and this appeared to be due to indirect effects of F420 loss of function (e.g., redox imbalance) rather than loss of a detoxification system. Together, these data show that F420 enhances antimicrobial resistance in mycobacteria and suggest that one function of the F420H2-dependent reductases is to broaden the range of natural products that mycobacteria and possibly other environmental actinobacteria can reductively detoxify
An X-ray spectral survey of the disc of M31 with XMM-Newton
We present the results of a complete spectral survey of the X-ray point
sources detected in five XMM-Newton observations along the major axis of M31
but avoiding the central bulge, aimed at establishing the population
characteristics of X-ray sources in this galaxy. We obtained background
subtracted spectra and lightcurves for each of the 335 X-ray point sources
detected across the five observations from 2002. We also correlate our source
list with those of earlier X-ray surveys and radio, optical and infra-red
catalogues. Sources with more than 50 source counts are individually spectrally
fit in order to create the most accurate luminosity functions of M31 to date.
Based on the spectral fitting of these sources with a power law model, we
observe a broad range of best fit photon index. From this distribution of best
fit index, we identify 16 strong high mass X-ray binary system candidates in
M31. We show the first cumulative luminosity functions created using the best
fit spectral model to each source with more than 50 source counts in the disc
of M31. The cumulative luminosity functions show a prominent, statistically
significant flattening in the X-ray luminosity LX interval 37.0 \lesssim log LX
erg s-1 \lesssim 37.5. Such a feature may also be present in the X-ray
populations of several other galaxies, but at a much lower statistical
significance. We investigate the number of AGN present in our source list and
find that above LX ~1.4x1036 erg s-1 the observed population is statistically
dominated by the point source population of M31.Comment: accepted by A&A. 24 pages, 6 figures, 7 table
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