336 research outputs found
Domestic Violence and its Determinants: A cross-sectional study among women in a slum of Kolkata
Background: Violence against women is one of the major public health and human rights issue in the world today which is prevalent in all human societies irrespective of religion, socioeconomic status, and culture. Therefore, recognized as a significant barrier to women empowerment and their health. Aims & Objectives: The aim of this study was to find out the extent of different type of domestic violence and to identify various risk factors for domestic violence against married women. Material & Methods: The present study is a community based cross-sectional study carried out in a slum of Kolkata. Simple random sampling technique was used for the selection of the samples. The study participants were interviewed using a pretested semi-structured questionnaire. Result: 97 married women participated in the study. 32.9% of the study population reported some form of domestic violence. In a logistic regression analysis, significant association was found between domestic violence and alcohol abuse by the spouse, level of education of the spouse, per capita income and occupation of the women. Conclusion: This study confirms, high prevalence of all forms of violence against women, which underscores the need for policy makers to increase their recognition of domestic violence as a critical target in public health concern
Human Immune Response to COVID-19 Infection and Potential Role of Chloroquine Family of Drugs: A Review
Currently, world is witnessing a massive morbidity and mortality due to COVID-19 pandemic. Â A novel strain of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). The virus enters inside the body and infect the cells through angiotensin-converting enzyme 2 (ACE2) receptor. The S1 protein of SARS-CoV-2 binds to the ACE2 receptor which results in endocytosis and transfer of virus into endosomes of body cells. Entry of SARS-CoV-2 results in activation of innate immune responses first followed by adaptive immune responses. The effective host immune responses are crucial to control and prevent viral infection. However, excessive production of proinflammatory cytokines and decrease in number of T-lymphocytes are the major reasons associated with severity of COVID-19. Therapies and drugs that can modulate the immune responses appropriately may play a crucial role to control and prevent the progression of disease. Chloroquine (CQ) and hydroxychloroquine (HCQ) have anti-inflammatory, immunomodulatory, antitumor, antimicrobial and antithrombotic effects. These drugs have already been registered in many countries to treat arthritis, lupus and malaria. The treatment responses of COVID-19 patients to these drugs have been found positive in some cases and clinical studies are underway for evaluating these drugs for the same. However, there are some serious side effects and health hazards associated. Many regulatory bodies are demanding more conclusive data on efficacy and safety from the clinical studies. Moreover, some regulatory bodies such as Food and Drug Administration (FDA) and European Medicines Agency (EMA) have recommended to use these drugs in emergency and chronic situation to treat critically ill COVID-19 patients under doctorâs supervision with all issued guidelines. The national task force (NTF) set up by Indian Council of Medical Research has recommended high risk individuals to take HCQ for prophylaxis. This review summarizes human immune response and various aspects of CQ and HCQ with special reference to COVID-19
Weierstrass meets Enriques
We study in detail the degeneration of K3 to T^4/Z_2. We obtain an explicit
embedding of the lattice of collapsed cycles of T^4/Z_2 into the lattice of
integral cycles of K3 in two different ways. Our first method exploits the
duality to the heterotic string on T^3. This allows us to describe the
degeneration in terms of Wilson lines. Our second method is based on the
blow-up of T^4/Z_2. From this blow-up, we directly construct the full lattice
of integral cycles of K3. Finally, we use our results to describe the action of
the Enriques involution on elliptic K3 surfaces, finding that a Weierstrass
model description is consistent with the Enriques involution only in the
F-theory limit.Comment: 35 pages, 9 figure
Heterotic Sigma Models with N=2 Space-Time Supersymmetry
We study the non-linear sigma model realization of a heterotic vacuum with
N=2 space-time supersymmetry. We examine the requirements of (0,2) + (0,4)
world-sheet supersymmetry and show that a geometric vacuum must be described by
a principal two-torus bundle over a K3 manifold.Comment: 20 pages, uses xy-pic; v3: typos corrected, reference added,
discussion of constraints on Hermitian form modifie
Heterotic type IIA duality with fluxes - towards the complete story
In this paper we study the heterotic type IIA duality when fluxes are turned
on. We show that many of the known fluxes are dual to each other and claim that
certain fluxes on the heterotic side require that the type IIA picture is
lifted to M or even F-theory compactifications with geometric fluxes.Comment: 31 pages, references adde
D-brane Charges in Gravitational Duals of 2+1 Dimensional Gauge Theories and Duality Cascades
We perform a systematic analysis of the D-brane charges associated with
string theory realizations of d=3 gauge theories, focusing on the examples of
the N=4 supersymmetric U(N)xU(N+M) Yang-Mills theory and the N=3 supersymmetric
U(N)xU(N+M) Yang-Mills-Chern-Simons theory. We use both the brane construction
of these theories and their dual string theory backgrounds in the supergravity
approximation. In the N=4 case we generalize the previously known gravitational
duals to arbitrary values of the gauge couplings, and present a precise mapping
between the gravity and field theory parameters. In the N=3 case, which (for
some values of N and M) flows to an N=6 supersymmetric Chern-Simons-matter
theory in the IR, we argue that the careful analysis of the charges leads to a
shift in the value of the B-field in the IR solution by 1/2, in units where its
periodicity is one, compared to previous claims. We also suggest that the N=3
theories may exhibit, for some values of N and M, duality cascades similar to
those of the Klebanov-Strassler theory.Comment: 47 pages, 9 figures; minor changes, references adde
Fluxes and Warping for Gauge Couplings in F-theory
We compute flux-dependent corrections in the four-dimensional F-theory
effective action using the M-theory dual description. In M-theory the 7-brane
fluxes are encoded by four-form flux and modify the background geometry and
Kaluza-Klein reduction ansatz. In particular, the flux sources a warp factor
which also depends on the torus directions of the compactification fourfold.
This dependence is crucial in the derivation of the four-dimensional action,
although the torus fiber is auxiliary in F-theory. In M-theory the 7-branes are
described by an infinite array of Taub-NUT spaces. We use the explicit metric
on this geometry to derive the locally corrected warp factor and M-theory
three-from as closed expressions. We focus on contributions to the 7-brane
gauge coupling function from this M-theory back-reaction and show that terms
quadratic in the internal seven-brane flux are induced. The real part of the
gauge coupling function is modified by the M-theory warp factor while the
imaginary part is corrected due to a modified M-theory three-form potential.
The obtained contributions match the known weak string coupling result, but
also yield additional terms suppressed at weak coupling. This shows that the
completion of the M-theory reduction opens the way to compute various
corrections in a genuine F-theory setting away from the weak string coupling
limit.Comment: 46 page
Super Weyl invariance: BPS equations from heterotic worldsheets
It is well-known that the beta functions on a string worldsheet correspond to
the target space equations of motion, e.g. the Einstein equations. We show that
the BPS equations, i.e. the conditions of vanishing supersymmetry variations of
the space-time fermions, can be directly derived from the worldsheet. To this
end we consider the RNS-formulation of the heterotic string with (2,0)
supersymmetry, which describes a complex torsion target space that supports a
holomorphic vector bundle. After a detailed account of its quantization and
renormalization, we establish that the cancellation of the Weyl anomaly
combined with (2,0) finiteness implies the heterotic BPS conditions: At the one
loop level the geometry is required to be conformally balanced and the gauge
background has to satisfy the Hermitean Yang-Mills equations.Comment: 1+31 pages LaTeX, 5 figures; final version, discussion relation Weyl
invariance and (2,0) finiteness extended, typos correcte
Spinning strings and integrable spin chains in the AdS/CFT correspondence
In this introductory review we discuss dynamical tests of the AdS_5 x S^5
string/N=4 super Yang-Mills duality. After a brief introduction to AdS/CFT we
argue that semiclassical string energies yield information on the quantum
spectrum of the string in the limit of large angular momenta on the S^5. The
energies of the folded and circular spinning string solutions rotating on a S^3
within the S^5 are derived, which yield all loop predictions for the dual gauge
theory scaling dimensions. These follow from the eigenvalues of the dilatation
operator of N=4 super Yang-Mills in a minimal SU(2) subsector and we display
its reformulation in terms of a Heisenberg s=1/2 spin chain along with the
coordinate Bethe ansatz for its explicit diagonalization. In order to make
contact to the spinning string energies we then study the thermodynamic limit
of the one-loop gauge theory Bethe equations and demonstrate the matching with
the folded and closed string result at this loop order. Finally the known gauge
theory results at higher-loop orders are reviewed and the associated long-range
spin chain Bethe ansatz is introduced, leading to an asymptotic all-loop
conjecture for the gauge theory Bethe equations. This uncovers discrepancies at
the three-loop order between gauge theory scaling dimensions and string theory
energies and the implications of this are discussed. Along the way we comment
on further developments and generalizations of the subject and point to the
relevant literature.Comment: 40 pages, invited contribution to Living Reviews in Relativity. v2:
improvements in the text and references adde
Uncertain future preferences and conservation
An important problem in environmental economics arises from te irreversibility of consuming or destroying certain resources. Extractive resources like oil are a clear example. Even for environmental resources the same seems to be true in a number of environmental cases, for example biodiversity, current climate conditions, or complex ecological systems. Irreversibility imposes a sever externality across different generations; future generations will suffer from the destruction of a unique asset like Amazonia, and it is not clear how such a loss could be compensated in terms of other goods. If such an asset is destroyed, then it is not possible to subsequently restore it. In contrast, if the asset is preserved, then it is possible to "use" the asset at a subsequent date. If there is uncertainty about future preferences or valuations, then preservation provides a type of insurance which is not available if the irreversible decision is carried out
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