3,375 research outputs found
Interactions of cultures and top people of Wikipedia from ranking of 24 language editions
Wikipedia is a huge global repository of human knowledge, that can be
leveraged to investigate interwinements between cultures. With this aim, we
apply methods of Markov chains and Google matrix, for the analysis of the
hyperlink networks of 24 Wikipedia language editions, and rank all their
articles by PageRank, 2DRank and CheiRank algorithms. Using automatic
extraction of people names, we obtain the top 100 historical figures, for each
edition and for each algorithm. We investigate their spatial, temporal, and
gender distributions in dependence of their cultural origins. Our study
demonstrates not only the existence of skewness with local figures, mainly
recognized only in their own cultures, but also the existence of global
historical figures appearing in a large number of editions. By determining the
birth time and place of these persons, we perform an analysis of the evolution
of such figures through 35 centuries of human history for each language, thus
recovering interactions and entanglement of cultures over time. We also obtain
the distributions of historical figures over world countries, highlighting
geographical aspects of cross-cultural links. Considering historical figures
who appear in multiple editions as interactions between cultures, we construct
a network of cultures and identify the most influential cultures according to
this network.Comment: 32 pages. 10 figures. Submitted for publication. Supporting
information is available on
http://www.quantware.ups-tlse.fr/QWLIB/topwikipeople
Advanced Denoising for X-ray Ptychography
The success of ptychographic imaging experiments strongly depends on
achieving high signal-to-noise ratio. This is particularly important in
nanoscale imaging experiments when diffraction signals are very weak and the
experiments are accompanied by significant parasitic scattering (background),
outliers or correlated noise sources. It is also critical when rare events such
as cosmic rays, or bad frames caused by electronic glitches or shutter timing
malfunction take place.
In this paper, we propose a novel iterative algorithm with rigorous analysis
that exploits the direct forward model for parasitic noise and sample
smoothness to achieve a thorough characterization and removal of structured and
random noise. We present a formal description of the proposed algorithm and
prove its convergence under mild conditions. Numerical experiments from
simulations and real data (both soft and hard X-ray beamlines) demonstrate that
the proposed algorithms produce better results when compared to
state-of-the-art methods.Comment: 24 pages, 9 figure
Mitochondrial ion channels as therapeutic targets
AbstractThe study of mitochondrial ion channels changed our perception of these double-wrapped organelles from being just the power house of a cell to the guardian of a cell’s fate. Mitochondria communicate with the cell through these special channels. Most of the time, the message is encoded by ion flow across the mitochondrial outer and inner membranes. Potassium, sodium, calcium, protons, nucleotides, and proteins traverse the mitochondrial membranes in an exquisitely regulated manner to control a myriad of processes, from respiration and mitochondrial morphology to cell proliferation and cell death. This review is an update on both well established and putative mitochondrial channels regarding their composition, function, regulation, and therapeutic potential
Optimal Reinsurance to Minimize the Probability of Drawdown under the Mean-Variance Premium Principle: Asymptotic Analysis
In this paper, we consider an optimal reinsurance problem to minimize the probability of drawdown
for the scaled Cram´er-Lundberg risk model when the reinsurance premium is computed
according to the mean-variance premium principle. We extend the work of Liang et al. [16] to
the case of minimizing the probability of drawdown. By using the comparison method and the
tool of adjustment coefficients, we show that the minimum probability of drawdown for the scaled
classical risk model converges to the minimum probability for its diffusion approximation, and the
rate of convergence is of order O(n−1/2). We further show that using the optimal strategy from
the diffusion approximation in the scaled classical risk model is O(n−1/2)-optimalEste documento es una versión del artÃculo publicado en SIAM Journal on Financial Mathematics, 14(1), 279–313Universidad Torcuato Di TellaHebei University of TechnologyDepartment of Mathematics, University of Michiga
B.-Y. Chen's inequality for submanifolds of generalized space forms
In this article, we investigate sharp inequalities involving δ-invariants for submanifolds in both generalized complex space forms and generalized Sasakian space forms, with arbitrary codimension.Ministerio de Educación y CienciaPlan Andaluz de Investigación (Junta de AndalucÃa
Poverty and Paternal Education Associated with Infant Safe Sleep Intentions in a Peri-Urban Community in Ecuador
Ecuador’s annual mortality rate from SIDS is 0.4 per 100 000 people, 4 times higher than neighboring countries Peru, Bolivia, and Brazil. Modifying the infant sleep environment toward safe practice has been demonstrated to be the most effective risk reduction strategy in reducing mortality from SIDS and little is known about sleep practices in Ecuador. The purpose of this study is to describe baseline infant sleep intentions of pregnant women in a peri-urban, low resource community in Ecuador. We also aim to identify demographic and psychosocial factors associated with suboptimal sleep practices in this context to develop long-term strategies to identify infants with high risk for SIDS/SUID. A cross-sectional study design was employed with 100 women in their third trimester of pregnancy. The majority of women were partnered (82%), both parents had approximately 8 years of education, and over half reported that their incomes met or exceeded their basic needs (55%). Significant predictors of safer sleep intention included years of paternal education (P = .019) and income meeting their basic needs (P = .0049). For each additional year of paternal education, families were 23% more likely to report safer intended infant sleep practices. Compared to those whose income did not allow for basic needs, those who had sufficient income to meet (or exceed) basic needs were 425% more likely to report safer intended sleep practices. Targeted interventions to high-risk populations may reduce the burden of SIDS/SUID in this community
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