989 research outputs found
Mode-Dependent Loss and Gain: Statistics and Effect on Mode-Division Multiplexing
In multimode fiber transmission systems, mode-dependent loss and gain
(collectively referred to as MDL) pose fundamental performance limitations. In
the regime of strong mode coupling, the statistics of MDL (expressed in
decibels or log power gain units) can be described by the eigenvalue
distribution of zero-trace Gaussian unitary ensemble in the small-MDL region
that is expected to be of interest for practical long-haul transmission.
Information-theoretic channel capacities of mode-division-multiplexed systems
in the presence of MDL are studied, including average and outage capacities,
with and without channel state information.Comment: 22 pages, 8 figure
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REDUCE-IT USA: Results From the 3146 Patients Randomized in the United States.
BackgroundSome trials have found that patients from the United States derive less benefit than patients enrolled outside the United States. This prespecified REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl - Intervention Trial) subgroup analysis was conducted to determine the degree of benefit of icosapent ethyl in the United States.MethodsREDUCE-IT randomized 8179 statin-treated patients with qualifying triglycerides ≥135 and <500 mg/dL and low-density lipoprotein cholesterol >40 and ≤100 mg/dL and a history of atherosclerosis or diabetes mellitus to icosapent ethyl 4 g/d or placebo. The primary composite end point was cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or hospitalization for unstable angina. The key secondary composite end point was cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. A hierarchy was prespecified for examination of individual and composite end points.ResultsA total of 3146 US patients (38.5% of the trial) were randomized and followed for a median of 4.9 years; 32.3% were women and 9.7% were Hispanic. The primary composite end point occurred in 24.7% of placebo-treated patients versus 18.2% of icosapent ethyl-treated patients (hazard ratio [HR], 0.69 [95% CI, 0.59-0.80]; P=0.000001); the key secondary composite end point occurred in 16.6% versus 12.1% (HR, 0.69 [95% CI, 0.57-0.83]; P=0.00008). All prespecified hierarchical end points were meaningfully and significantly reduced, including cardiovascular death (6.7% to 4.7%; HR, 0.66 [95% CI, 0.49-0.90]; P=0.007), myocardial infarction (8.8% to 6.7%; HR, 0.72 [95% CI, 0.56-0.93]; P=0.01), stroke (4.1% to 2.6%; HR, 0.63 [95% CI, 0.43-0.93]; P=0.02), and all-cause mortality (9.8% to 7.2%; HR, 0.70 [95% CI, 0.55-0.90]; P=0.004); for all-cause mortality in the US versus non-US patients, Pinteraction=0.02. Safety and tolerability findings were consistent with the full study cohort.ConclusionsWhereas the non-US subgroup showed significant reductions in the primary and key secondary end points, the US subgroup demonstrated particularly robust risk reductions across a variety of individual and composite end points, including all-cause mortality.Clinical trial registrationURL: https://www.clinicaltrials.gov. Unique identifier: NCT01492361
Differentiating normal and problem gambling: a grounded theory approach.
A previous study (Ricketts & Macaskill, 2003) delineated a theory of problem gambling based on the experiences of treatment seeking male gamblers and allowed predictions to be made regarding the processes that differentiate between normal and problem gamblers. These predictions are the focus of the present study, which also utilised a grounded theory approach, but with a sample of male high frequency normal gamblers. The findings suggest that there are common aspects of gambling associated with arousal and a sense of achievement. The use of gambling to manage negative emotional states differentiated normal and problem gambling. Perceived self-efficacy , emotion management skills and perceived likelihood of winning money back were intervening variables differentiating problem and normal gamblers.</p
Subsurface Pore Water Contributions to Stream Concentration-Discharge Relations Across a Snowmelt Hydrograph
This study investigated the concentration discharge (C-Q) patterns of selected elements transported to streams during spring snowmelt through an instrumented mixed-conifer forested catchment in rhyolitic terrain in the Jemez Mountains (NM, United States). High frequency, concurrent sampling of soil solution and gasses, groundwater, and surface water enabled identification and sourcing of five groups of solutes with distinct C-Q behavior. Non-hydrolyzing cations and strong acid anions, had mostly positive C-Q relations and a clockwise hysteresis pattern related to flushing of a limited reservoir of solutes accumulated in soils under snowpack. Rare earth elements (REEs) and dissolved organic carbon (DOC), demonstrated large positive C-Q relations and a clockwise hysteresis pattern, consistent with their co-transport as metal-ligand complexes, and signaling biologically induced weathering reactions in the soil. Silicon and dissolved inorganic carbon (DIC) exhibited chemostatic C-Q trends and an anti-clockwise hysteresis pattern consistent with sourcing from deep groundwater. Hydrolyzing metals (Mn, Al, Ti, and Zr) with high coefficients of variance (CV) for concentration relative to CV values for stream discharge and with no significant C-Q pattern, were found to be transported mainly as filterable colloids. Fe C-Q behavior was similar to this hydrolyzing metals group, but complexation with DOC was also important for Fe during the initial stage of the snowmelt hydrograph. Investigation of time-series of solutes and gasses provided evidence for biologically induced silicate weathering reactions that initiated in the soil subsurface and propagated down through groundwater to streams
Population assessment of future trajectories in coronary heart disease mortality.
Background:
Coronary heart disease (CHD) mortality rates have been decreasing in Iceland since the 1980s, largely
reflecting improvements in cardiovascular risk factors. The purpose of this study was to predict future CHD mortality in
Iceland based on potential risk factor trends.
Methods and findings:
The previously validated IMPACT model was used to predict changes in CHD mortality between 2010 and 2040 among the projected population of Iceland aged 25–74. Calculations were based on combining: i) data on population numbers and projections (Statistics Iceland), ii) population risk factor levels and projections (Refine Reykjavik study), and iii) effectiveness of specific risk factor reductions (published meta-analyses). Projections for three contrasting
scenarios were compared: 1) If the historical risk factor trends of past 30 years were to continue, the declining death rates of past decades would level off, reflecting population ageing. 2) If recent trends in risk factors (past 5 years) continue, this would result in a death rate increasing from 49 to 70 per 100,000. This would reflect a recent plateau in previously falling cholesterol levels and recent rapid increases in obesity and diabetes prevalence. 3) Assuming that in 2040 the entire population enjoys optimal risk factor levels observed in low risk cohorts, this would prevent almost all premature CHD deaths before 2040.
Conclusions:
The potential increase in CHD deaths with recent trends in risk factor levels is alarming both for Iceland and
probably for comparable Western populations. However, our results show considerable room for reducing CHD mortality.
Achieving the best case scenario could eradicate premature CHD deaths by 2040. Public health policy interventions based
on these predictions may provide a cost effective means of reducing CHD mortality in the future
The effect of cardiac resynchronization without a defibrillator on morbidity and mortality: an individual patient data meta-analysis of COMPANION and CARE-HF
AIMS: Cardiac resynchronization therapy (CRT) reduces morbidity and mortality for patients with heart failure, reduced left ventricular ejection fraction, QRS duration >130 ms and in sinus rhythm. The aim of this study was to identify patient characteristics that predict the effect, specifically, of CRT pacemakers (CRT-P) on all-cause mortality or the composite of hospitalization for heart failure or all-cause mortality. METHODS AND RESULTS: We conducted an individual patient data meta-analysis of the Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION) and Cardiac Resynchronization-Heart Failure (CARE-HF) trials. Only patients assigned to CRT-P or control (n = 1738) were included in order to avoid confounding from concomitant defibrillator therapy. The influence of baseline characteristics on treatment effects was investigated. Median age was 67 (59-73) years, most patients were men (70%), 68% had a QRS duration of 150-199 ms and 80% had left bundle branch block. Patients assigned to CRT-P had lower rates for all-cause mortality (hazard ratio [HR] 0.68, 95% confidence interval [CI] 0.56-0.81; p < 0.0001) and the composite outcome (HR 0.67, 95% CI 0.58-0.78; p < 0.0001). No pre-specified characteristic, including sex, aetiology of ventricular dysfunction, QRS duration (within the studied range) or morphology or PR interval significantly influenced the effect of CRT-P on all-cause mortality or the composite outcome. However, CRT-P had a greater effect on the composite outcome for patients with lower body surface area and those prescribed beta-blockers. CONCLUSIONS: Cardiac resynchronization therapy-pacemaker reduces morbidity and mortality in appropriately selected patients with heart failure. Benefits may be greater in smaller patients and in those receiving beta-blockers. Neither QRS duration nor morphology independently predicted the benefit of CRT-P. CLINICAL TRIAL REGISTRATION: COMPANION, NCT00180258; CARE-HF, NCT00170300
DCC dynamics with the SU(3) linear sigma model
The SU(3) extension of the linear sigma model is employed to elucidate the
effect of including strangeness on the formation of disoriented chiral
condensates. By means of a Hartree factorization, approximate dispersion
relations for the 18 scalar and pseudoscalar meson species are derived and
their self-consistent solution makes it possible to trace out the thermal path
of the two order parameters as well as delineate the region of instability
within which spontaneous pair creation becomes possible. The results depend
significantly on the employed sigma mass, with the highest values yielding the
largest regions of instability. An approximate solution of the equations of
motion for the order parameter in scenarios emulating uniform scaling
expansions show that even with a rapid quench only the pionic modes grow
unstable. Nevertheless, the rapid and oscillatory relaxation of the order
parameters leads to enhanced production of both pions and (to a lesser degree)
kaons.Comment: 29 pages, RevTeX, 11 postscript figures, discussion about anomaly
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Age-specific trends in cardiovascular mortality rates in the Netherlands between 1980 and 2009
Recent analyses suggest the decline in coronary heart disease mortality rates is slowing in younger age groups in countries such as the US and the UK. This work aimed to analyse recent trends in cardiovascular mortality rates in the Netherlands. Analysis was of annual all circulatory, ischaemic heart disease (IHD), and cerebrovascular disease mortality rates between 1980 and 2009 for the Netherlands. Data were stratified by sex and 10-year age group (age 35–85+). The annual rate of change and significant changes in the trend were identified using joinpoint Poisson regression. For almost all age and sex groups examined the rate of IHD and cerebrovascular disease mortality in the Netherlands has more than halved between 1980 and 2009. The decline in mortality from both IHD and cerebrovascular disease is continuing for all ages and sex groups, with anacceleration in the decline apparent from the late 1990s/early 2000s. The decline in age-specific all circulatory, coronary heart disease and cerebrovascular disease mortality rates continues for all age and sex groups in the Netherlands
Targeting BMI-1 to deplete antibody-secreting cells in autoimmunity
Objectives. B cells drive the production of autoreactive antibodysecreting cells, ASCs, in autoimmune diseases such as Systemic Lupus Erythematosus, SLE, and Sjogren, s syndrome, causing long-, term organ damage. Current treatments for antibody-mediated autoimmune diseases target B cells or broadly suppress the immune system. However, pre-existing long-lived ASCs are often refractory to treatment, leaving a reservoir of autoreactive cells that continue to produce antibodies. Therefore, the development of novel treatment methods targeting ASCs is vital to improve patient outcomes. Our objective was to test whether targeting the epigenetic regulator BMI-, could deplete ASCs in autoimmune conditions in vivo and in vitro. Methods. Use of a BMI-, inhibitor in both mouse and human autoimmune settings was investigated. Lyn, mice, a model of SLE, were treated with the BMI-, small molecule inhibitor PTC-, before assessment of ASCs, serum antibody and immune complexes. To examine human ASC survival, a novel human fibroblast-based assay was established, and the impact of PTC-, on ASCs derived from Sjogren, s syndrome, patients was evaluated. Results. BMI-, inhibition significantly decreased splenic and bone marrow ASCs in Lyn, mice. The decline in ASCs was linked to aberrant cell cycle gene expression and led to a significant decrease in serum IgG, immune complexes and anti-DNA IgG. PTC-, was also efficacious in reducing ex vivo plasma cell survival from both Sjogren, s syndrome, patients and age-matched healthy donors. Conclusion. These data provide evidence that inhibiting BMI-, can deplete ASC in a variety of contexts and thus BMI-, is a viable therapeutic target for antibody-mediated autoimmune diseases.Jack Polmear, Lauren Hailes, Moshe Olshansky, Maureen Rischmueller, Elan L'Estrange-Stranieri, Anne L Fletcher, Margaret L Hibbs, Vanessa L Bryant, Kim L Good-Jacobso
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