25 research outputs found
Constraining PBH mass distributions from 21cm brightness temperature results and an analytical mapping between probability distribution of 21cm signal and PBH masses
The evaporation of Primordial Black Hole (PBH) via Hawking radiation
influences the evolution of Inter Galactic Medium by heating up the latter and
consequently affects the 21cm signal originated from the neutral Hydrogen
atoms. In this work, we have considered EDGES observational data of 21cm line
corresponding to cosmic dawn era to constrain the mass and the abundance of
PBHs. In this context, two different PBH mass distributions namely, power law
and lognormal mass distributions are considered to estimate the effects of PBH
evaporation on the 21cm brightness temperature . In addition to these
two mass distributions, different monochromatic masses are also considered. The
impacts of Dark Matter - baryon interactions on are also considered in
this work along with the influences of PBH evaporation. Furthermore, adopting
different monochromatic masses for PBHs, an attempt has been made to formulate
a distribution for PBH masses by associating a probability weightage of the
values (at ), within the range given by EDGES experiment,
with the calculated values for each of the PBH mass values. The
distribution best suited for the present purpose is found to be a combination
of an error function and Owen function. Allowed contours in the parameter space
of (initial PBH mass-dark matter mass) are obtained.Comment: 17 pages, 9 figure
Addressing the self-interaction for ELDER dark matter from the 21-cm signal
The self-interacting dark matter can affect various cosmological processes.
Such interactions can be number conserving (\emph{e.g.} ) or
number violating (\emph{e.g.} etc.). The
latter processes where three (or more) dark matter particles undergo
self-annihilation/scattering to produce less number of dark matter is termed as
``Cannibalism'' process. In this work, the self-interaction of dark matter and
the strength of such interactions are investigated in the light of experimental
results of the global 21-cm spectrum of neural hydrogen from the era of cosmic
dawn. From the present work, it appears that process is much
more dominant over the process. It is also found that such
interactions affect the dark matter-baryon elastic scattering cross-section.
The study also indicates the presence of multi component dark matter of
different mass range in the Universe.Comment: 19 pages, 5 figure
Five Pond-centred Outbreaks of Cholera in Villages of West Bengal, India: Evidence for Focused Interventions
In rural West Bengal, outbreaks of cholera are often centred around ponds that is a feature of the environment. Five investigations of laboratory-confirmed, pond-centred outbreaks of cholera were reviewed. Case-control odds ratios were approximated with relative risks (RRs) as the incidence was low. The environment was investigated to understand how the pond(s) could have become contaminated and could have infected villagers. The five outbreaks of cholera in 2004-2008 led to 277 cases and three deaths (median attack rate: 51/1,000 people; case fatality: 1.1%; median age of case-patients: 22 years; median duration: 13 days, range: 6-15 days). Factors significantly (p<0.05) associated with cholera in the case-control (n=4) and cohort investigations (n=1) included washing utensils in ponds (4 outbreaks of cholera, RR range: 6-12), bathing (3 outbreaks of cholera, RR range: 3.5-9.3), and exposure to pond water, including drinking (2 outbreaks of cholera, RR range: 2.1-3.2), mouth washing (1 outbreak of cholera, RR: 4.8), and cooking (1 outbreak of cholera, RR: 3.0). Initial case-patients contaminated ponds through washing soiled clothes (n=4) or defaecation (n=1). Ubiquitous ponds used for many purposes transmit cholera in West Bengal. Focused health education, hygiene, and sanitation must protect villagers, particularly following the occurrence of an index case in a village that has ponds
Knowledge, attitudes, and practices related to antibiotic use in Paschim Bardhaman District: A survey of healthcare providers in West Bengal, India
IntroductionAntibiotic misuse is widespread and contributes to antibiotic resistance, especially in less regulated health systems such as India. Although informal providers are involved with substantial segments of primary healthcare, their level of knowledge, attitudes, and practices is not well documented in the literature.ObjectivesThis quantitative study systematically examines the knowledge, attitudes, and practices of informal and formal providers with respect to antibiotic use.MethodsWe surveyed a convenience sample of 384 participants (96 allopathic doctors, 96 nurses, 96 informal providers, and 96 pharmacy shopkeepers) over a period of 8 weeks from December to February using a validated questionnaire developed in Italy. Our team created an equivalent, composite KAP score for each respondent in the survey, which was subsequently compared between providers. We then performed a multivariate logistic regression analysis to estimate the odds of having a low composite score (ResultsDoctors scored highest in questions assessing knowledge (77.3%) and attitudes (87.3%), but performed poorly in practices (67.6%). Many doctors knew that antibiotics were not indicated for viral infections, but over 87% (n = 82) reported prescribing them in this situation. Nurses, pharmacy shopkeepers, and informal providers were more likely to perform poorly on the survey compared to allopathic doctors (OR: 10.4, 95% CI 5.4, 20.0, pConclusionsOur findings indicate poor knowledge and awareness of antibiotic use and functions among informal health providers, and dissonance between knowledge and practices among allopathic doctors. The nexus between allopathic doctors, pharmaceutical company representatives, and informal health providers present promising avenues for future research and intervention
Five Pond-centred Outbreaks of Cholera in Villages of West Bengal, India: Evidence for Focused Interventions
In rural West Bengal, outbreaks of cholera are often centred around
ponds that is a feature of the environment. Five investigations of
laboratory-confirmed, pond-centred outbreaks of cholera were reviewed.
Case-control odds ratios were approximated with relative risks (RRs) as
the incidence was low. The environment was investigated to understand
how the pond(s) could have become contaminated and could have infected
villagers. The five outbreaks of cholera in 2004-2008 led to 277 cases
and three deaths (median attack rate: 51/1,000 people; case fatality:
1.1%; median age of case-patients: 22 years; median duration: 13 days,
range: 6-15 days). Factors significantly (p<0.05) associated with
cholera in the case-control (n=4) and cohort investigations (n=1)
included washing utensils in ponds (4 outbreaks of cholera, RR range:
6-12), bathing (3 outbreaks of cholera, RR range: 3.5-9.3), and
exposure to pond water, including drinking (2 outbreaks of cholera, RR
range: 2.1-3.2), mouth washing (1 outbreak of cholera, RR: 4.8), and
cooking (1 outbreak of cholera, RR: 3.0). Initial case-patients
contaminated ponds through washing soiled clothes (n=4) or defaecation
(n=1). Ubiquitous ponds used for many purposes transmit cholera in West
Bengal. Focused health education, hygiene, and sanitation must protect
villagers, particularly following the occurrence of an index case in a
village that has ponds