44 research outputs found
Stability and evolution of electromagnetic solitons in relativistic degenerate laser plasmas
The dynamical behaviors of electromagnetic (EM) solitons formed due to
nonlinear interaction of linearly polarized intense laser light and
relativistic degenerate plasmas are studied. In the slow motion approximation
of relativistic dynamics, the evolution of weakly nonlinear EM envelope is
described by the generalized nonlinear Schr{\"o}dinger (GNLS) equation with
local and nonlocal nonlinearities. Using the Vakhitov-Kolokolov criteria, the
stability of an EM soliton solution of the GNLS equation is studied. Different
stable and unstable regions are demonstrated with the effects of soliton
velocity, soliton eigenfrequency, as well as the degeneracy parameter
, where is the Fermi momentum and the electron
mass, and is the speed of light in vacuum. It is found that the stability
region shifts to an unstable one and is significantly reduced as one enters
from the regimes of weakly relativistic to ultrarelativistic
degeneracy of electrons. The analytically predicted results are in
good agreement with the simulation results of the GNLS equation. It is shown
that the standing EM soliton solutions are stable. However, the moving solitons
can be stable or unstable depending on the values of soliton velocity, the
eigenfrequency or the degeneracy parameter. The latter with strong degeneracy
can eventually lead to soliton collapse.Comment: 9 pages, 5 figure
National Center for Biomedical Ontology: Advancing biomedicine through structured organization of scientific knowledge
The National Center for Biomedical Ontology is a consortium that comprises leading informaticians, biologists, clinicians, and ontologists, funded by the National Institutes of Health (NIH) Roadmap, to develop innovative technology and methods that allow scientists to record, manage, and disseminate biomedical information and knowledge in machine-processable form. The goals of the Center are (1) to help unify the divergent and isolated efforts in ontology development by promoting high quality open-source, standards-based tools to create, manage, and use ontologies, (2) to create new software tools so that scientists can use ontologies to annotate and analyze biomedical data, (3) to provide a national resource for the ongoing evaluation, integration, and evolution of biomedical ontologies and associated
tools and theories in the context of driving biomedical projects (DBPs), and (4) to disseminate the tools and resources of the Center and to identify, evaluate, and communicate best practices of ontology development to the biomedical community. Through the research activities within the Center, collaborations with the DBPs, and interactions with the biomedical community, our goal is to help scientists to work more effectively in the e-science paradigm, enhancing experiment design, experiment execution, data analysis, information synthesis, hypothesis generation and testing, and understand human disease
Nursing Personnel Planning for Rural Hospitals in Burdwan District, West Bengal, India, Using Workload Indicators of Staffing Needs
Lack of appropriate human resources planning is an important factor in
the inefficient use of the public health facilities. Workforce
projections can be improved by using objective methods of staffing
needs based on the workload and actual work undertaken by workers, a
guideline developed by Peter J. Shipp in collaboration with
WHO\u2014Workload Indicators of Staffing Need (WISN). A
cross-sectional study was carried out to estimate the nursing stuff
requirement for the rural hospitals and provide a quantitative
description of imbalances, if there is any, in the allocation at the
district level during 2011. The average WISN turns out to be 0.35 for
entire district, which means only 35% of the required nurses is
available or 65% understaffed. So, there is an urgent need for more
allocations and deployment of staff so that workload can be tackled and
evenly distributed among all nursing personnel
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Annotation of the Drosophila melanogaster euchromatic genome: a systematic review
BACKGROUND: The recent completion of the Drosophila melanogaster genomic sequence to high quality and the availability of a greatly expanded set of Drosophila cDNA sequences, aligning to 78% of the predicted euchromatic genes, afforded FlyBase the opportunity to significantly improve genomic annotations. We made the annotation process more rigorous by inspecting each gene visually, utilizing a comprehensive set of curation rules, requiring traceable evidence for each gene model, and comparing each predicted peptide to SWISS-PROT and TrEMBL sequences. RESULTS: Although the number of predicted protein-coding genes in Drosophila remains essentially unchanged, the revised annotation significantly improves gene models, resulting in structural changes to 85% of the transcripts and 45% of the predicted proteins. We annotated transposable elements and non-protein-coding RNAs as new features, and extended the annotation of untranslated (UTR) sequences and alternative transcripts to include more than 70% and 20% of genes, respectively. Finally, cDNA sequence provided evidence for dicistronic transcripts, neighboring genes with overlapping UTRs on the same DNA sequence strand, alternatively spliced genes that encode distinct, non-overlapping peptides, and numerous nested genes. CONCLUSIONS: Identification of so many unusual gene models not only suggests that some mechanisms for gene regulation are more prevalent than previously believed, but also underscores the complex challenges of eukaryotic gene prediction. At present, experimental data and human curation remain essential to generate high-quality genome annotations
National Center for Biomedical Ontology: Advancing Biomedicine through Structured Organization of Scientific Knowledge
Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019
Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin
Global, regional, and national burden of hepatitis B, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019
The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019
Background In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults. Findings There were 1.19 million (95% UI 1.11-1.28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59.6 [54.5-65.7] per 100 000 person-years) and high-middle SDI countries (53.2 [48.8-57.9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14.2 [12.9-15.6] per 100 000 person-years) and middle SDI (13.6 [12.6-14.8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23.5 million (21.9-25.2) DALYs to the global burden of disease, of which 2.7% (1.9-3.6) came from YLDs and 97.3% (96.4-98.1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe
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Prevalence, years lived with disability, and trends in anaemia burden by severity and cause, 1990-2021: findings from the Global Burden of Disease Study 2021
Background
Anaemia is a major health problem worldwide. Global estimates of anaemia burden are crucial for developing appropriate interventions to meet current international targets for disease mitigation. We describe the prevalence, years lived with disability, and trends of anaemia and its underlying causes in 204 countries and territories.
Methods
We estimated population-level distributions of haemoglobin concentration by age and sex for each location from 1990 to 2021. We then calculated anaemia burden by severity and associated years lived with disability (YLDs). With data on prevalence of the causes of anaemia and associated cause-specific shifts in haemoglobin concentrations, we modelled the proportion of anaemia attributed to 37 underlying causes for all locations, years, and demographics in the Global Burden of Disease Study 2021.
Findings
In 2021, the global prevalence of anaemia across all ages was 24·3% (95% uncertainty interval [UI] 23·9–24·7), corresponding to 1·92 billion (1·89–1·95) prevalent cases, compared with a prevalence of 28·2% (27·8–28·5) and 1·50 billion (1·48–1·52) prevalent cases in 1990. Large variations were observed in anaemia burden by age, sex, and geography, with children younger than 5 years, women, and countries in sub-Saharan Africa and south Asia being particularly affected. Anaemia caused 52·0 million (35·1–75·1) YLDs in 2021, and the YLD rate due to anaemia declined with increasing Socio-demographic Index. The most common causes of anaemia YLDs in 2021 were dietary iron deficiency (cause-specific anaemia YLD rate per 100 000 population: 422·4 [95% UI 286·1–612·9]), haemoglobinopathies and haemolytic anaemias (89·0 [58·2–123·7]), and other neglected tropical diseases (36·3 [24·4–52·8]), collectively accounting for 84·7% (84·1–85·2) of anaemia YLDs.
Interpretation
Anaemia remains a substantial global health challenge, with persistent disparities according to age, sex, and geography. Estimates of cause-specific anaemia burden can be used to design locally relevant health interventions aimed at improving anaemia management and prevention.
Funding
Bill & Melinda Gates Foundation
Mobile phone usage pattern among undergraduate medical students at a Medical College of Kolkata, West Bengal, India
AbstractObjective: Mobile phone usage has reached all ages across all segments of society, and its radiofrequency waves are an increasing concern among the general population. To find out the pattern of mobile phone usage among undergraduate medical students and their perceived symptoms and awareness about negative health effects due to their exposure to the radiofrequency waves. Methods: A descriptive type of epidemiological study was conducted among 295 undergraduate medical students in the Institute of Post Graduate Medical Education and Research, Kolkata, in August 2012 after obtaining Institutional Ethical Clearance. Data were collected by a pre-designed and pre-tested, semi structured questionnaire and analyzed with SPSS software, version 19.0. Results: Among the 1st semester students, browsing of the internet became the predominant activity; while listening to music and radio was the preferred activity among the 3rd, 5th and 7th semester students. In lecture class, 1st semester students (62.5%) switch off; 40.6% of 5th semester students receive and 63.63% of 7th semester students keep the phone in silence mode. Duration of mobile phone usage was maximum among students who perceived headache as a side effect of usage. About 62.3% study subjects cited accidents as a harmful effect, followed by lack of concentration. Conclusions: Regulatory bodies should lay down specific regulations and guidelines regarding mobile phone usage in class as well as during patient care. Further research is needed to comment on long term health outcome keeping in view its usage and popularity among younger people. Keywords: Mobile phone use, medical students, hazard awareness </p