1,630 research outputs found
On the Price of Anarchy of Highly Congested Nonatomic Network Games
We consider nonatomic network games with one source and one destination. We
examine the asymptotic behavior of the price of anarchy as the inflow
increases. In accordance with some empirical observations, we show that, under
suitable conditions, the price of anarchy is asymptotic to one. We show with
some counterexamples that this is not always the case. The counterexamples
occur in very simple parallel graphs.Comment: 26 pages, 6 figure
Effect of maternal Schistosoma mansoni infection and praziquantel treatment during pregnancy on Schistosoma mansoni infection and immune responsiveness among offspring at age five years.
INTRODUCTION: Offspring of Schistosoma mansoni-infected women in schistosomiasis-endemic areas may be sensitised in-utero. This may influence their immune responsiveness to schistosome infection and schistosomiasis-associated morbidity. Effects of praziquantel treatment of S. mansoni during pregnancy on risk of S. mansoni infection among offspring, and on their immune responsiveness when they become exposed to S. mansoni, are unknown. Here we examined effects of praziquantel treatment of S. mansoni during pregnancy on prevalence of S. mansoni and immune responsiveness among offspring at age five years. METHODS: In a trial in Uganda (ISRCTN32849447, http://www.controlled-trials.com/ISRCTN32849447/elliott), offspring of women treated with praziquantel or placebo during pregnancy were examined for S. mansoni infection and for cytokine and antibody responses to SWA and SEA, as well as for T cell expression of FoxP3, at age five years. RESULTS: Of the 1343 children examined, 32 (2.4%) had S. mansoni infection at age five years based on a single stool sample. Infection prevalence did not differ between children of treated or untreated mothers. Cytokine (IFNγ, IL-5, IL-10 and IL-13) and antibody (IgG1, Ig4 and IgE) responses to SWA and SEA, and FoxP3 expression, were higher among infected than uninfected children. Praziquantel treatment of S. mansoni during pregnancy had no effect on immune responses, with the exception of IL-10 responses to SWA, which was higher in offspring of women that received praziquantel during pregnancy than those who did not. CONCLUSION: We found no evidence that maternal S. mansoni infection and its treatment during pregnancy influence prevalence and intensity of S. mansoni infection or effector immune response to S. mansoni infection among offspring at age five years, but the observed effects on IL-10 responses to SWA suggest that maternal S. mansoni and its treatment during pregnancy may affect immunoregulatory responsiveness in childhood schistosomiasis. This might have implications for pathogenesis of the disease
Transient accumulation of 5-carboxylcytosine indicates involvement of active demethylation in lineage specification of neural stem cells
5-Methylcytosine (5mC) is an epigenetic modificationinvolved in regulation of gene activity during differentiation. Tet dioxygenases oxidize 5mC to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC). Both 5fC and 5caC can be excised from DNA by thymine-DNA glycosylase (TDG) followed by regeneration of unmodified cytosine via the base excision repair pathway. Despite evidence that this mechanism is operative in embryonic stem cells, the role of TDG-dependent demethylation in differentiation and development is currently unclear. Here, we demonstrate that widespread oxidation of 5hmC to 5caC occurs in postimplantation mouse embryos. We show that 5fC and 5caC are transiently accumulated during lineage specification of neural stem cells (NSCs) in culture and invivo. Moreover, 5caC is enriched at the cell-type-specific promoters during differentiation of NSCs, and TDG knockdown leads to increased 5fC/5caC levels in differentiating NSCs. Our data suggest that active demethylation contributes to epigenetic reprogramming determining lineage specification in embryonic brain. © 2014 The Authors
Bad news travels fast! | Notícia ruim corre depressa!
Many proverbs are created through everyday experience. Although many of them are readily understood by ordinary people, the more detailed view generates many questions and doubts related to their credibility. Motivated by one of these proverbs, in the present paper, we analyse propagation of news in the network of electronic contacts (e-mails). More specifically, we propose transmission protocols intended to reproduce properties of real systems. These protocols are simulated in a real e-mail network and in the random network proposed by p. Erdos and a. Rényi prize. The results suggest that news spreads faster in the random network. The hubs in the real network tend to attract the news, in prejudice to the less connected nodes
Congested traffic equilibria and degenerate anisotropic PDEs
Congested traffic problems on very dense networks lead, at the limit, to minimization problems posed on measures on curves as shown in Baillon and Carlier (Netw. Heterogenous Media 7: 219--241, 2012). Here, we go one step further by showing that these problems can be reformulated in terms of the minimization of an integral functional over a set of vector fields with prescribed divergence. We prove a Sobolev regularity result for their minimizers despite the fact that the Euler-Lagrange equation of the dual is highly degenerate and anisotropic. This somehow extends the analysis of Brasco et al. (J. Math. Pures Appl. 93: 652--671, 2010) to the anisotropic case
Black rings with fourth dipole cause less hair loss
An example of entropy enigma with a controlled CFT dual was recently studied
in arXiv:1108.0411. The enigmatic bulk configurations, considered within the
STU model, can be mapped under spectral flow into black rings with three
monopole and dipole charges. Even though the bulk and CFT configurations
existed in the same region of parameter space, the Bekenstein-Hawking entropy
of the bulk configurations was found to be lower than the microscopic entropy
from the CFT. While it is possible that the difference in entropy is due to the
bulk and boundary configurations being at different points in the moduli space,
it is also possible that the bulk configurations embeddable within the STU
model are not the most entropic. New families of BPS black ring solutions with
four electric and four dipole magnetic charges have recently been explicitly
constructed in arXiv:1201.2585. These black rings are not embeddable within the
STU model. In this paper we investigate if these black rings can be
entropically dominant over the STU model black rings. We find that the new
black rings are always entropically subdominant to the STU-model black rings.
However, for small fourth dipole charge these black rings continue to be
dominant over the BMPV in a small region of parameters and are thus enigmatic.Comment: v2: minor changes, references added, 15 pages, 9 figures (published
version
Integrability of Green-Schwarz Sigma Models with Boundaries
We construct integrability preserving boundary conditions for Green-Schwarz
sigma-models on semi-symmetric spaces. The boundary conditions are expressed as
gluing conditions of the flat-connection, using an involutive metric preserving
automorphism. We show that the boundary conditions preserve half of the
space-time supersymmetry and an infinite set of conserved charges. We find
integrable D-brane configurations for AdS_5 x S^5 and AdS_4 x CP^3 backgrounds.Comment: 24 pages. v2 references added. v3 typos fixed, sec. 3 improved,
references added, published versio
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