50 research outputs found
A selected bibliography on parameter optimization methods suitable for hybrid computation
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68333/2/10.1177_003754976700800610.pd
Evidence of stochastic resonance in the mating behavior of Nezara viridula (L.)
We investigate the role of the noise in the mating behavior between
individuals of Nezara viridula (L.), by analyzing the temporal and spectral
features of the non-pulsed type female calling song emitted by single
individuals. We have measured the threshold level for the signal detection, by
performing experiments with the calling signal at different intensities and
analyzing the insect response by directionality tests performed on a group of
male individuals. By using a sub-threshold signal and an acoustic Gaussian
noise source, we have investigated the insect response for different levels of
noise, finding behavioral activation for suitable noise intensities. In
particular, the percentage of insects which react to the sub-threshold signal,
shows a non-monotonic behavior, characterized by the presence of a maximum, for
increasing levels of the noise intensity. This constructive interplay between
external noise and calling signal is the signature of the non-dynamical
stochastic resonance phenomenon. Finally, we describe the behavioral activation
statistics by a soft threshold model which shows stochastic resonance. We find
that the maximum of the ensemble average of the input-output cross-correlation
occurs at a value of the noise intensity very close to that for which the
behavioral response has a maximum.Comment: 6 pages, 4 figures, to appear in EPJ B (2008
Particles-vortex interactions and flow visualization in He4
Recent experiments have demonstrated a remarkable progress in implementing
and use of the Particle Image Velocimetry (PIV) and particle tracking
techniques for the study of turbulence in He4. However, an interpretation of
the experimental data in the superfluid phase requires understanding how the
motion of tracer particles is affected by the two components, the viscous
normal fluid and the inviscid superfluid. Of a particular importance is the
problem of particle interactions with quantized vortex lines which may not only
strongly affect the particle motion, but, under certain conditions, may even
trap particles on quantized vortex cores. The article reviews recent
theoretical, numerical, and experimental results in this rapidly developing
area of research, putting critically together recent results, and solving
apparent inconsistencies. Also discussed is a closely related technique of
detection of quantized vortices negative ion bubbles in He4.Comment: To appear in the J Low Temperature Physic
Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.
BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
Discrepancies in the availability of open access services: comparison between the Northern and Oxford regions
General practitioners have long been aware of variations in the range of open access services available to them.This study compares the availability of 22 open access services in the Northern and Oxford regions and examines possible reasons for variations. From data collected from general practitioners and community managers two striking patterns emerge. First, there is a difference between the regions with wider availability in the Oxford region. Secondly, there are differences in the range of services available between health authorities, sometimes neighbouring, within the same region, although this is less marked in Oxford.These discrepancies probably reflect the situation nationally and it would appear questionable whether there is any policy coordination at regional or national level to ensure an equitable distribution of open access services
Dendroclimatic investigations and cross-dating in the 1700s: the tree-ring investigations of Johan Leche (1704â1764) in southwestern Finland
Lectin binding characteristics of haemocytes and parasites in the oyster, Crassostrea virginicd, infected with Haplosporidium nelsoni (MSX)
In or out? Methodological considerations for including and excluding findings from a meta-analysis of predictors of antiretroviral adherence in HIV-positive women
AIM: This paper is a discussion detailing the decisions concerning whether to include or exclude findings from a meta-analysis of report of quantitative studies of antiretroviral adherence in HIV-positive women. BACKGROUND: Publication constraints and the absence of reflexivity as a criterion for validity in, and reporting of, quantitative research preclude detailing the many judgements made in the course of a meta-analysis. Yet, such an accounting would assist researchers better to address the unique challenges to meta-analysis presented by the bodies of research they have targeted for review, and to show the subjectivity, albeit disciplined, that characterizes the meta-analytic process. DATA SOURCES: Data were 29 published and unpublished studies on antiretroviral adherence in HIV-positive women of any race/ethnicity, class, or nationality living in the United States of America. The studies were retrieved between June 2005 and January 2006 using 40 databases. REVIEW METHODS: Findings were included if they met the statistical assumptions of meta-analysis, including: (1) normal distribution of observations; (2) homogeneity of variances; and (3) independence of observations. RESULTS: Relevant studies and findings were excluded because of issues related to differences in study design, different operationalizations of dependent and independent variables, multiple cuts from common longitudinal data sets, and presentation of unadjusted and adjusted findings. These reasons led to the exclusion of 73% of unadjusted relationships and 87% of adjusted relationships from our data set, leaving few findings to synthesize. CONCLUSION: Decisions made during research synthesis studies may result in more information losses than gains, thereby obliging researchers to find ways to preserve findings that are potentially valuable for practice