1,269 research outputs found
Implications of binary black hole detections on the merger rates of double neutron stars and neutron star-black holes
We show that the inferred merger rate and chirp masses of binary black holes
(BBHs) detected by advanced LIGO (aLIGO) can be used to constrain the rate of
double neutron star (DNS) and neutron star - black hole (NSBH) mergers in the
universe. We explicitly demonstrate this by considering a set of publicly
available population synthesis models of \citet{Dominik:2012kk} and show that
if all the BBH mergers, GW150914, LVT151012, GW151226, and GW170104, observed
by aLIGO arise from isolated binary evolution, the predicted DNS merger rate
may be constrained to be ~\rate~ and that of NSBH mergers will be
constrained to ~\rate. The DNS merger rates are not constrained much
but the NSBH rates are tightened by a factor of as compared to their
previous rates. Note that these constrained DNS and NSBH rates are extremely
model dependent and are compared to the unconstrained values \rate~
and \rate, respectively, using the same models of
\citet{Dominik:2012kk}. These rate estimates may have implications for short
Gamma Ray Burst progenitor models assuming they are powered (solely) by DNS or
NSBH mergers. While these results are based on a set of open access population
synthesis models which may not necessarily be the representative ones, the
proposed method is very general and can be applied to any number of models
thereby yielding more realistic constraints on the DNS and NSBH merger rates
from the inferred BBH merger rate and chirp mass.Comment: 5 pages, no figures, 4 tables, v2: matches published versio
A study of incidence, risk factors, clinical profile and management of 50 cases of ectopic pregnancy in a tertiary care teaching hospital
Background: Ectopic pregnancy is a challenging and life-threatening emergency, which can cause significant maternal morbidity and mortality. The present study aims at determining the incidence, risk factors, clinical features, diagnosis, management and outcome of ectopic pregnancies in a tertiary care teaching hospital.Methods: This was a prospective study of 50 cases of ectopic pregnancies admitted to the Department of Obstetrics and Gynaecology at a tertiary care teaching hospital from August 2012 to September 2013. Relevant data of the 50 patients was tabulated and descriptive analysis was carried out.Results: The incidence of ectopic pregnancy was 6.3 per 1000 deliveries. Majority of the patients (82%) belonged to 20-30 yrs age group. 70% of the women were multiparous. The commonest site of ectopic pregnancy was fallopian tube (92 %). Past history of pelvic inflammatory disease (40%), abortions (20%), abdominopelvic surgery (14%) and IUCD usage (12%) were among the important risk factors identified. 20% of the patients had no identifiable risk factor. The classical triad of amenorrhea, bleeding per vaginum and abdominal pain was seen in 56 % of the study population. The most important signs which guided the diagnosis of ectopic pregnancy were cervical excitation pain (74%), abdominal tenderness (72%), adnexal mass or fullness (68%) and tenderness in the fornix (68%). Clinical presentation, urinary pregnancy test, culdocentesis and ultrasound were the diagnostic tools used for diagnosis of ectopic pregnancy. The incidence of ruptured ectopic pregnancy was 86%. Majority of the patients underwent salpingectomy (96%). There was no maternal mortality in our study.Conclusions: Early diagnosis, timely referral, improved access to health care, aggressive management and improvement of blood bank facilities can reduce the maternal morbidity and mortality associated with ectopic pregnancy
Impact of Prisoner Population on the Prison Rehabilitation Process in Sri Lanka
Prison is one of the main and important agencies which involves in the criminal justice process. Offenders who are sentenced to imprisonment are sent to this institution for rehabilitation. The main objective of the prison institution is to rehabilitate prisoners thereby helping them to understand what was wrong with their behaviors and helping them to become productive citizens in the future after releasing from prison. In order to achieve this task, the prison system should take necessary steps to conduct an effective rehabilitation process during the imprisonment period. The study was based on to study the impact of the prisoners population on the prison rehabilitation process in Sri Lanka.. The objective of the research was to identify basic rehabilitation problems caused by the prisoners population. The research was conducted in Mahara prison in the Gampaha District of the western province. The study sample included 50 prisoners out of 1500 prisoners of Mahara prison. The sample was selected using systematic sampling which is one of the probability sampling methods used. And also prison officers were selected under the same sample. The data obtained from the research have been extensively analyzed quantitatively and qualitatively. The finding reveals that the physical and human resources in prisons are limited compared to the increasing number of prisoners, referrals from prisoners to vocational sectors have decreased, and 66% of prisoners have health problems. Meanwhile, there are sexually transmitted diseases and rashes. Furthermore, remanded prisoners have increased due to delays in cases. To increase the effectiveness of the rehabilitation process, the prisoner population must be controlled, for that, it is important to have an interconnection between the court and prison.
DOI: http://doi.org/10.31357/fhss/vjhss.v08i01.0
Dietary risk factors for childhood asthma in a semi-urban area of South India: A cross-sectional study
Background: Although inhaled allergens are more likely to trigger asthma than food allergens, global trends of asthma prevalence emphasize the role of changing dietary habits in modulating the inflammatory mediators involved in the pathogenesis of asthma. Objective: The objective of the study was to identify the dietary risk factors associated with childhood asthma in a semi-urban region of South India. Materials and Methods: This was a cross-sectional study done at a medical college hospital in South India from October 2016 to January 2017. After obtaining the Ethical Committee approval, children aged 3β15 years attending the pediatric outpatient department were enrolled in the study. Parents were interviewed with a precoded Food Frequency Questionnaire. Details regarding common dietary practices followed at home, frequency of consumption of specific food groups and history of food allergy were obtained. Chi-square tests and logistic regression analysis were used to analyze the data. Results: Among 500 subjects, 293 (58.6%) children had physician-diagnosed asthma. Duration of breastfeeding was <1 year (OR 2.01, 95% CI 1.35β2.99); frequent intake of fast food (OR 2.70, 95% CI 1.61β4.52), usage of coloring agents and taste enhancers in cooking (OR 3.93, 95% CI 1.53β10.06), and history of allergy to specific foods (OR 2.21, 95% CI 1.42β3.45) were found to be independent risk factors for childhood asthma. The absence of fish in the diet was significantly associated with increased risk of asthma (OR 1.50, 1.04β2.15) and non-vegetarians were at lesser risk (OR 0.43, 0.24β0.76) of developing asthma. Conclusion: Prolonged duration of breastfeeding (>1 year), restriction of fast food, and avoidance of food additives decrease the risk of asthma in children. Non-vegetarian diet with the inclusion of fish offers a protective effect against asthma. Early identification and appropriate management of coexisting food allergies in children with asthma are necessary
Testing the multipole structure and conservative dynamics of compact binaries using gravitational wave observations: The spinning case
In an earlier work [S. Kastha et al., PRD {\bf 98}, 124033 (2018)], we
developed the {\it parametrized multipolar gravitational wave phasing formula}
to test general relativity, for the non-spinning compact binaries in
quasi-circular orbit. In this paper, we extend the method and include the
important effect of spins in the inspiral dynamics. Furthermore, we consider
parametric scaling of PN coefficients of the conserved energy for the compact
binary, resulting in the parametrized phasing formula for non-precessing
spinning compact binaries in quasi-circular orbit. We also compute the
projected accuracies with which the second and third generation ground-based
gravitational wave detector networks as well as the planned space-based
detector LISA will be able to measure the multipole deformation parameters and
the binding energy parameters. Based on different source configurations, we
find that a network of third-generation detectors would have comparable ability
to that of LISA in constraining the conservative and dissipative dynamics of
the compact binary systems. This parametrized multipolar waveform would be
extremely useful not only in deriving the first upper limits on any deviations
of the multipole and the binding energy coefficients from general relativity
using the gravitational wave detections, but also for science case studies of
next generation gravitational wave detectors.Comment: 16 pages, 8 figures, Mathematica readable supplemental material file
for all the inputs to calculate the parametrized waveform is with the sourc
A novel ensemble modeling for intrusion detection system
Vast increase in data through internet services has made computer systems more vulnerable and difficult to protect from malicious attacks. Intrusion detection systems (IDSs) must be more potent in monitoring intrusions. Therefore an effectual Intrusion Detection system architecture is built which employs a facile classification model and generates low false alarm rates and high accuracy. Noticeably, IDS endure enormous amounts of data traffic that contain redundant and irrelevant features, which affect the performance of the IDS negatively. Despite good feature selection approaches leads to a reduction of unrelated and redundant features and attain better classification accuracy in IDS. This paper proposes a novel ensemble model for IDS based on two algorithms Fuzzy Ensemble Feature selection (FEFS) and Fusion of Multiple Classifier (FMC). FEFS is a unification of five feature scores. These scores are obtained by using feature-class distance functions. Aggregation is done using fuzzy union operation. On the other hand, the FMC is the fusion of three classifiers. It works based on Ensemble decisive function. Experiments were made on KDD cup 99 data set have shown that our proposed system works superior to well-known methods such as Support Vector Machines (SVMs), K-Nearest Neighbor (KNN) and Artificial Neural Networks (ANNs). Our examinations ensured clearly the prominence of using ensemble methodology for modeling IDSs. And hence our system is robust and efficient
Black holes in the low mass gap: Implications for gravitational wave observations
Binary neutron-star mergers will predominantly produce black-hole remnants of
mass , thus populating the putative \emph{low mass gap}
between neutron stars and stellar-mass black holes. If these low-mass black
holes are in dense astrophysical environments, mass segregation could lead to
"second-generation" compact binaries merging within a Hubble time. In this
paper, we investigate possible signatures of such low-mass compact binary
mergers in gravitational-wave observations. We show that this unique population
of objects, if present, will be uncovered by the third-generation
gravitational-wave detectors, such as Cosmic Explorer and Einstein Telescope.
Future joint measurements of chirp mass and effective spin
could clarify the formation scenario of compact objects in the
low mass gap. As a case study, we show that the recent detection of GW190425
(along with GW170817) favors a double Gaussian mass model for neutron stars,
under the assumption that the primary in GW190425 is a black hole formed from a
previous binary neutron star merger.Comment: 8 pages, 4 figures, 1 table. v4: matches the version accepted for
publication in Phys. Rev.
Multiparameter tests of general relativity using multiband gravitational-wave observations
In this Letter we show that multiband observations of stellar-mass binary
black holes by the next generation of ground-based observatories (3G) and the
space-based Laser Interferometer Space Antenna (LISA) would facilitate a
comprehensive test of general relativity by simultaneously measuring all the
post-Newtonian (PN) coefficients. Multiband observations would measure most of
the known PN phasing coefficients to an accuracy below a few percent---two
orders-of-magnitude better than the best bounds achievable from even `golden'
binaries in the 3G or LISA bands. Such multiparameter bounds would play a
pivotal role in constraining the parameter space of modified theories of
gravity beyond general relativity.Comment: 7 pages, 4 figures. v3: version published in PR
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