1,305 research outputs found
Evolution of the density parameter in the anisotropic DGP cosmology
Evolution of the density parameter in the anisotropic DGP braneworld model is
studied. The role of shear and cross-over scale in the evolution of
is examined for both the branches of solution in the DGP model.
The evolution is modified significantly compared to the FRW model and further
it does not depend on the value of alone. Behaviour of the
cosmological density parameter is unaltered in the late universe.
The study of decceleration parameter shows that the entry of the universe into
self accelerating phase is determined by the value of shear. We also obtain an
estimate of the shear parameter ,
which is in agreement with the constraints obtained in the literature using
data.Comment: To apper in Int.J.Mod.Phys.D, 14 pages, 6 figure
Evaluation of bias correction methods for a multivariate drought index: case study of the Upper Jhelum Basin
Bias correction (BC) is often a necessity to improve the applicability of
global and regional climate model (GCM and RCM, respectively) outputs to
impact assessment studies, which usually depend on multiple potentially
dependent variables. To date, various BC methods have been developed which
adjust climate variables separately (univariate BC) or jointly (multivariate
BC) prior to their application in impact studies (i.e., the component-wise
approach). Another possible approach is to first calculate the multivariate
hazard index from the original, biased simulations and bias-correct the
impact model output or index itself using univariate methods (direct
approach). This has the advantage of circumventing the difficulties
associated with correcting the inter-variable dependence of climate
variables which is not considered by univariate BC methods.
Using a multivariate drought index (i.e., standardized precipitation
evapotranspiration index – SPEI) as an example, the present
study compares different state-of-the-art BC methods (univariate and
multivariate) and BC approaches (direct and component-wise) applied to
climate model simulations stemming from different experiments at different
spatial resolutions (namely Coordinated Regional Climate Downscaling Experiment (CORDEX), CORDEX Coordinated Output for Regional Evaluations (CORDEX-CORE), and 6th Coupled Intercomparison Project (CMIP6)). The BC methods
are calibrated and evaluated over the same historical period (1986–2005).
The proposed framework is demonstrated as a case study over a transboundary
watershed, i.e., the Upper Jhelum Basin (UJB) in the Western Himalayas.
Results show that (1) there is some added value of multivariate BC methods
over the univariate methods in adjusting the inter-variable relationship;
however, comparable performance is found for SPEI indices. (2) The best-performing BC methods exhibit a comparable performance under both approaches
with a slightly better performance for the direct approach. (3) The added
value of the high-resolution experiments (CORDEX-CORE) compared to their
coarser-resolution counterparts (CORDEX) is not apparent in this study.</p
The prevalence of domestic violence among pregnant women in Nigeria: a systematic review.
To identify, appraise, and synthesize research evidence on the prevalence of domestic violence (DV) among pregnant women in Nigeria. We conducted a systematic review of all published studies between April 2004 and June 2016. Comprehensive searches were conducted on electronic databases such as PubMed, CINAHL, Global Health, MEDLINE, PsycINFO, Directory of Open Access Journals, Google Scholar, and electronic libraries of the authors' institution. Identified articles were screened in two stages against the inclusion criteria with titles and abstract screened first followed by full-text screening. Selected articles were assessed using the "guidelines for evaluating prevalence studies," and findings were synthesized narratively. Among 19 studies that met the inclusion criteria, two articles were excluded due to low methodological quality and 17 articles were included in the review. The prevalence of DV during pregnancy in Nigeria ranged between 2.3% and 44.6% with lifetime prevalence rates ranging between 33.1% and 63.2%. Physical, sexual, psychological, and verbal abuses were the most frequent types of DV reported in this review. The most common perpetrators were husbands, as reported in 11 of the 17 studies. Pregnant women between the ages of 20 and 30 years were the most common victims of DV. Our review suggests high prevalence of DV in pregnancy among women in Nigeria and higher lifetime prevalence. However, determining an overall, synthesized accurate prevalence rate of DV within this population based on existing evidence presents a challenge. The findings have important implications for stakeholders such as planners, policy makers, maternity care providers, and researchers in public health and social policy at national, regional, and international levels toward combating the issue. OBJECTIVE METHOD RESULTS CONCLUSIO
Primary and malignant cholangiocytes undergo CD40 mediated Fas dependent Apoptosis, but are insensitive to direct activation with exogenous fas ligand
Introduction
Cholangiocarcinoma is a rare malignancy of the biliary tract, the incidence of which is rising, but the pathogenesis of which remains uncertain. No common genetic defects have been described but it is accepted that chronic inflammation is an important contributing factor. We have shown that primary human cholangiocyte and hepatocyte survival is tightly regulated via co-operative interactions between two tumour necrosis family (TNF) receptor family members; CD40 and Fas (CD95). Functional deficiency of CD154, the ligand for CD40, leads to a failure of clearance of biliary tract infections and a predisposition to cholangiocarcinoma implying a direct link between TNF receptor-mediated apoptosis and the development of cholangiocarcinoma.
Aims
To determine whether malignant cholangiocytes display defects in CD40 mediated apoptosis. By comparing CD40 and Fas-mediated apoptosis and intracellular signalling in primary human cholangiocytes and three cholangiocyte cell lines.
Results
Primary cholangiocytes and cholangiocyte cell lines were relatively insensitive to direct Fas-mediated killing with exogenous FasL when compared with Jurkat cells, which readily underwent Fas-mediated apoptosis, but were extremely sensitive to CD154 stimulation. The sensitivity of cells to CD40 activation was similar in magnitude in both primary and malignant cells and was STAT-3 and AP-1 dependent in both.
Conclusions
1) Both primary and malignant cholangiocytes are relatively resistant to Fas–mediated killing but show exquisite sensitivity to CD154, suggesting that the CD40 pathway is intact and fully functional in both primary and malignant cholangiocytes 2) The relative insensitivity of cholangiocytes to Fas activation demonstrates the importance of CD40 augmentation of Fas dependent death in these cells. Agonistic therapies which target CD40 and associated intracellular signalling pathways may be effective in promoting apoptosis of malignant cholangiocytes
Popular Culture, Radical Egalitarianism, and Formations of Muslim Selfhood in South Asia
In early twentieth century leftist politics on the geographical fringes of South Asia, Islam played a major role. Were activists in these movements leftist despite their understandings of Islam, or because of them? This essay introduces the project represented in the essays of this special section of South Asian History and Culture, as well as the essays that will appear in a complementary section in a subsequent issue this year. The editors of this project reconstruct a conversation on surprising resonances in subaltern sources in Pashto and Bengali of early twentieth-century grassroots indigenous traditions of radical Muslim egalitarianism. What should we make of these resonances? Building on Latin American decolonisation theory in the wake of Subaltern Studies, we introduce a series of articles that together illustrate what Ramon Grosfoguel calls a ‘pluriverse’ of perspectives on the ethical self: some rooted in the local lifeworlds of Bengal and some in the Afghan borderland; all interlinked through a series of ‘middle actors’. In so doing, we excavate some dense but hidden two-way traffic between subaltern worlds of Muslim piety and devotion on two distant ends of South Asia, and all-India, international or cosmopolitan politics. These together helped constitute a surprising amount of what we know as the South Asian left, from what are usually seen as its geographical, social, and especially intellectual peripheries
Brain mapping in cognitive disorders: a multidisciplinary approach to learning the tools and applications of functional neuroimaging
<p>Abstract</p> <p>Background</p> <p>With rapid advances in functional imaging methods, human studies that feature functional neuroimaging techniques are increasing exponentially and have opened a vast arena of new possibilities for understanding brain function and improving the care of patients with cognitive disorders in the clinical setting. There is a growing need for medical centers to offer clinically relevant functional neuroimaging courses that emphasize the multifaceted and multidisciplinary nature of this field. In this paper, we describe the implementation of a functional neuroimaging course focusing on cognitive disorders that might serve as a model for other medical centers. We identify key components of an active learning course design that impact student learning gains in methods and issues pertaining to functional neuroimaging that deserve consideration when optimizing the medical neuroimaging curriculum.</p> <p>Methods</p> <p>Learning gains associated with the course were assessed using polychoric correlation analysis of responses to the SALG (Student Assessment of Learning Gains) instrument.</p> <p>Results</p> <p>Student gains in the functional neuroimaging of cognition as assessed by the SALG instrument were strongly associated with several aspects of the course design.</p> <p>Conclusion</p> <p>Our implementation of a multidisciplinary and active learning functional neuroimaging course produced positive learning outcomes. Inquiry-based learning activities and an online learning environment contributed positively to reported gains. This functional neuroimaging course design may serve as a useful model for other medical centers.</p
Role of proline, K/Na ratio and chlorophyll content in salt tolerance of wheat (Triticum aestivum
Abstract Studies to determine the role of proline, K/Na ratio and chlorophyll contents in salt tolerance of wheat genotypes were conducted in lysimeters using hydroponics technique. Seeds were allowed to germinate under normal condition (1.5 dS m -1 ) and salinity treatment of 12 dS m -1 was imposed after one week of germination. Crop was irrigated at the interval of two weeks or whenever required with 1/4 th Hoagland nutrient solution of respective concentrations. Results clearly indicated that wheat genotypes with higher proline, K/Na ratio and chlorophyll contents had higher grain yield. On the basis of yield reduction, three genotypes viz. Lu-26s, Sarsabz and KTDH were found tolerant. These genotypes also maintained the higher concentration of proline, K/Na ratio and chlorophyll contents under saline conditions
Dynamics in nonlocal linear models in the Friedmann-Robertson-Walker metric
A general class of cosmological models driven by a nonlocal scalar field
inspired by the string field theory is studied. Using the fact that the
considering linear nonlocal model is equivalent to an infinite number of local
models we have found an exact special solution of the nonlocal Friedmann
equations. This solution describes a monotonically increasing Universe with the
phantom dark energy.Comment: 18 pages, 3 figures, a few misprints in Section 5 have been correcte
Nonclassical Fields and the Nonlinear Interferometer
We demonstrate several new results for the nonlinear interferometer, which
emerge from a formalism which describes in an elegant way the output field of
the nonlinear interferometer as two-mode entangled coherent states. We clarify
the relationship between squeezing and entangled coherent states, since a weak
nonlinear evolution produces a squeezed output, while a strong nonlinear
evolution produces a two-mode, two-state entangled coherent state. In between
these two extremes exist superpositions of two-mode coherent states manifesting
varying degrees of entanglement for arbitrary values of the nonlinearity. The
cardinality of the basis set of the entangled coherent states is finite when
the ratio is rational, where is the nonlinear strength. We
also show that entangled coherent states can be produced from product coherent
states via a nonlinear medium without the need for the interferometric
configuration. This provides an important experimental simplification in the
process of creating entangled coherent states.Comment: 21 pages, 2 figure
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