100 research outputs found
Effects of calibration uncertainties on the detection and parameter estimation of isotropic gravitational-wave backgrounds
Gravitational-wave backgrounds are expected to arise from the superposition
of gravitational wave signals from a large number of unresolved sources and
also from the stochastic processes that occurred in the Early universe. So far,
we have not detected any gravitational wave background, but with the
improvements in the detectors' sensitivities, such detection is expected in the
near future. The detection and inferences we draw from the search for a
gravitational-wave background will depend on the source model, the type of
search pipeline used, and the data generation in the gravitational-wave
detectors. In this work, we focus on the effect of the data generation process,
specifically the calibration of the detectors' digital output into strain data
used by the search pipelines. Using the calibration model of the current LIGO
detectors as an example, we show that for power-law source models and
calibration uncertainties , the detection of isotropic
gravitational wave background is not significantly affected. We also show that
the source parameter estimation and upper limits calculations get biased. For
calibration uncertainties of , the biases are not significant
(), but for larger calibration uncertainties, they might become
significant, especially when trying to differentiate between different models
of isotropic gravitational-wave backgrounds.Comment: 11 pages, 7 figure
Surgical and functional outcome of management of anterior column with posterior hemitransverse fracture of acetabulum
Fractures of acetabulum are relatively uncommon, but as they involve the major weight bearing joint in lower extremity, they assume great clinical importance. The displaced acetabular fracture fragments result in hip joint incongruity which in turn leads to abnormal pressure distribution over the articular cartilage surface. This may lead to accelerated breakdown of the articular cartilage, resulting in disabling irreversible arthritis of hip joint. The aim of treatment of these difficult acetabular fractures is concentric reduction of femur head under the weight bearing dome of acetabulum resulting in anatomic reduction and followed by a stable fixation. This can be achieved only by adequately exposing the acetabulum and by rigid internal fixation. In our series 20 patients were included. Majority of the patients were males with mean age of 43.85±16.88 years. Most common mechanism of injury was road traffic accident. Right side was most affected. Most of the cases were isolated injuries. Majority of the cases had no complications. At the final follow up, most of the cases had Excellent follow-up according to Modified Merle d’Aubigne and Postel score. Surgical management of Anterior column with posterior hemitransverse fracture of acetabulum gives excellent outcomes with least number of complications
A study of health profile and effects of ambient air pollution among auto drivers of Bangalore city
Background: Auto drivers battle several occupational health hazards due to increasing pollution and unhealthy lifestyle. Improper diet and sleeping habits coupled with smoking, tobacco and alcohol use make them prone to respiratory and cardiovascular health hazards. Objectives: To assess the health status and quality of life (QoL) among auto drivers in Bangalore city and to study the association of selected parameters with respiratory and cardiac morbidities. Methods: In this cross-sectional study, 450 auto drivers were given a questionnaire and they were distributed according to age, education, body mass index, smoking, tobacco and/or alcohol consumption. The QoL was assessed by World Health Organization Quality of Life Instrument (WHOQOL-BREF) and peak expiratory flow, blood pressure, and blood sugar levels for each participant were recorded. The association between two categorical variables was determined by Chi-square test and p?0.05 was considered statistically significant. Results: The association of number of years of driving with prevalence of chronic morbidity (p=0.005), hypertension (p=0.008), diabetes (p<0.001), and heart disease (p=0.04) were significant. QoL for physical and environmental domain were 16.11±0.28 and 12.48±0.06, respectively. Conclusion: A proportional increase in the risk of respiratory and cardiac morbidities with increasing number of driving years was observed among auto drivers
Puzzles of excited charm meson masses
We attempt a comprehensive analysis of the low lying charm meson states which
present several puzzles, including the poor determination of masses of several
non-strange excited mesons. We use the well-determined masses of the ground
states and the strange first excited states to `predict' the mass of the
non-strange first excited state in the framework of heavy hadron chiral
perturbation theory, an approach that is complementary to the well-known
analysis of Mehen and Springer. This approach points to values for the masses
of these states that are smaller than the experimental determinations. We
provide a critical assessment of these mass measurements and point out the need
for new experimental information.Comment: 9 pages, 1 figure, accepted for publication in Physics Letters
FUNDAMENTAL ANALYSIS -A STUDY OF SELECTED STOCKS IN TELECOM SECTOR
ABSTRACT Fundamental analysis is a logical and systematic approach t
Injury analysis using Anthropomorphic Test Device under vertical shock loads
Natural and manmade injuries due to terrorism, military weapon and accidents lead to cutting edge research for engineers and clinicians alike. The study of injury and its mechanism can help in predicting the severity of an injury which in turn shall guide the engineers to design safer structures and medical specialists in treating casualties. This article summarizes the various advancements and technologies available in the field of Injury Analysis. The objective of the study is to quantify the levels of an injury which occurs when an Anthropomorphic Test Device is subjected to a given vertical impact load. As a baseline a half sine shock test simulating the vertical impact was carried out on Hybrid III 50th percentile male dummy and injury analysis was done based on the standards prescribed by NATO TR-HFM-090. In the present test the injury analysis predicts that the injury during the loading is well within 10% probability of an AIS 2 or greater (AIS 2+)
Calibration Uncertainty for Advanced LIGO's First and Second Observing Runs
Calibration of the Advanced LIGO detectors is the quantification of the
detectors' response to gravitational waves. Gravitational waves incident on the
detectors cause phase shifts in the interferometer laser light which are read
out as intensity fluctuations at the detector output. Understanding this
detector response to gravitational waves is crucial to producing accurate and
precise gravitational wave strain data. Estimates of binary black hole and
neutron star parameters and tests of general relativity require well-calibrated
data, as miscalibrations will lead to biased results. We describe the method of
producing calibration uncertainty estimates for both LIGO detectors in the
first and second observing runs.Comment: 15 pages, 21 figures, LIGO DCC P160013
Understanding Aquaporin Transport System in Eelgrass (Zostera marina L.), an Aquatic Plant Species
Aquaporins (AQPs) are a class of integral membrane proteins involved in the transport of water and many other small solutes. The AQPs have been extensively studied in many land species obtaining water and nutrients from the soil, but their distribution and evolution have never been investigated in aquatic plant species, where solute assimilation is mostly through the leaves. In this regard, identification of AQPs in the genome of Zostera marina L. (eelgrass), an aquatic ecological model species could reveal important differences underlying solute uptake between land and aquatic species. In the present study, genome-wide analysis led to the identification of 25 AQPs belonging to four subfamilies, plasma membrane intrinsic proteins (PIPs), tonoplast intrinsic proteins (TIPs), nodulin 26-like intrinsic proteins (NIPs), small basic intrinsic proteins (SIPs) in eelgrass. As in other monocots, the XIP subfamily was found to be absent from the eelgrass genome. Further classification of subfamilies revealed a unique distribution pattern, namely the loss of the NIP2 (NIP-III) subgroup, which is known for silicon (Si) transport activity and ubiquitously present in monocot species. This finding has great importance, since the eelgrass population stability in natural niche is reported to be associated with Si concentrations in water. In addition, analysis of available RNA-seq data showed evidence of expression in 24 out of the 25 AQPs across four different tissues such as root, vegetative tissue, male flower and female flower. In contrast to land plants, higher expression of PIPs was observed in shoot compared to root tissues. This is likely explained by the unique plant architecture of eelgrass where most of the nutrients and water are absorbed by shoot rather than root tissues. Similarly, higher expression of the TIP1 and TIP5 families was observed specifically in male flowers suggesting a role in pollen maturation. This genome-wide analysis of AQP distribution, evolution and expression dynamics can find relevance in understanding the adaptation of aquatic and land species to their respective environments
Characterization of callase (β-1,3-d-glucanase) activity during microsporogenesis in the sterile anthers of Allium sativum L. and the fertile anthers of A. atropurpureum
We examined callase activity in anthers of sterile Allium sativum (garlic) and fertile Allium atropurpureum. In A. sativum, a species that produces sterile pollen and propagates only vegetatively, callase was extracted from the thick walls of A. sativum microspore tetrads exhibited maximum activity at pH 4.8, and the corresponding in vivo values ranged from 4.5 to 5.0. Once microspores were released, in vitro callase activity peaked at three distinct pH values, reflecting the presence of three callase isoforms. One isoform, which was previously identified in the tetrad stage, displayed maximum activity at pH 4.8, and the remaining two isoforms, which were novel, were most active at pH 6.0 and 7.3. The corresponding in vivo values ranged from pH 4.75 to 6.0. In contrast, in A. atropurpureum, a sexually propagating species, three callase isoforms, active at pH 4.8–5.2, 6.1, and 7.3, were identified in samples of microsporangia that had released their microspores. The corresponding in vivo value for this plant was 5.9. The callose wall persists around A. sativum meiotic cells, whereas only one callase isoform, with an optimum activity of pH 4.8, is active in the acidic environment of the microsporangium. However, this isoform is degraded when the pH rises to 6.0 and two other callase isoforms, maximally active at pH 6.0 and 7.3, appear. Thus, factors that alter the pH of the microsporangium may indirectly affect the male gametophyte development by modulating the activity of callase and thereby regulating the degradation of the callose wall
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