Aggregating partial, local evaluations to achieve global ranking

We analyze some voting models mimicking online evaluation systems intended to reduce the information overload. The minimum number of operations needed for a system to be effective is analytically estimated. When herding effects are present, linear preferential attachment marks a transition between trustful and biased reputations.Comment: 9 pages, 5 figures, accepted for publication in Physica

Decoding Information from noisy, redundant, and intentionally-distorted sources

Advances in information technology reduce barriers to information propagation, but at the same time they also induce the information overload problem. For the making of various decisions, mere digestion of the relevant information has become a daunting task due to the massive amount of information available. This information, such as that generated by evaluation systems developed by various web sites, is in general useful but may be noisy and may also contain biased entries. In this study, we establish a framework to systematically tackle the challenging problem of information decoding in the presence of massive and redundant data. When applied to a voting system, our method simultaneously ranks the raters and the ratees using only the evaluation data, consisting of an array of scores each of which represents the rating of a ratee by a rater. Not only is our appraoch effective in decoding information, it is also shown to be robust against various hypothetical types of noise as well as intentional abuses.Comment: 19 pages, 5 figures, accepted for publication in Physica

The SIB Swiss Institute of Bioinformatics' resources: focus on curated databases

The SIB Swiss Institute of Bioinformatics (www.isb-sib.ch) provides world-class bioinformatics databases, software tools, services and training to the international life science community in academia and industry. These solutions allow life scientists to turn the exponentially growing amount of data into knowledge. Here, we provide an overview of SIB's resources and competence areas, with a strong focus on curated databases and SIB's most popular and widely used resources. In particular, SIB's Bioinformatics resource portal ExPASy features over 150 resources, including UniProtKB/Swiss-Prot, ENZYME, PROSITE, neXtProt, STRING, UniCarbKB, SugarBindDB, SwissRegulon, EPD, arrayMap, Bgee, SWISS-MODEL Repository, OMA, OrthoDB and other databases, which are briefly described in this article

No evidence of an immune adjustment in response to a parasitoid threat in Lobesia botrana larvae

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The dopamine-synthesizing cells in the swimming larva of the tunicate Ciona intestinalis are located only in the hypothalamus-related domain of the sensory vesicle.

CD is in the laboratory of Neurobiologie des processus adaptatifs from 2005International audienceDopamine is a major neuromodulator synthesized by numerous cell populations in the vertebrate forebrain and midbrain. Owing to the simple organization of its larval nervous system, ascidian tunicates provide a useful model to investigate the anatomy, neurogenesis and differentiation of the dopaminergic neural network underlying the stereotypical swimming behaviour of its chordate-type larva. This study provides a high-resolution cellular analysis of tyrosine hydroxylase (TH)-positive and dopamine-positive cells in Ciona intestinalis embryos and larvae. Dopamine cells are present only in the sensory vesicle of the Ciona larval brain, which may be an ancestral chordate feature. The dopamine-positive cells of the ascidian sensory vesicle are located in the expression domain of homologues of vertebrate hypothalamic markers. We show here that the larval coronet cells also arise from this domain. As a similar association between coronet cells and the hypothalamus was reported in bony and cartilaginous fishes, we propose that part of the ascidian ventral sensory vesicle is the remnant of a proto-hypothalamus that may have been present in the chordate ancestor. As dopaminergic cells are specified in the hypothalamus in all vertebrates, we suggest that the mechanisms of dopamine cell specification are conserved in the hypothalamus of Ciona and vertebrates. To test this hypothesis, we have identified new candidate regulators of dopaminergic specification in Ciona based on their expression patterns, which can now be compared with those in vertebrates

Regulatory gene expressions in the ascidian ventral sensory vesicle: evolutionary relationships with the vertebrate hypothalamus

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Identification of risk factors for postpartum urinary retention following vaginal deliveries: A retrospective case-control study

International audienceObjective: Postpartum urinary retention (PUR) is an uncommon complication of vaginal delivery, defined as a failure to void spontaneously in the six hours following vaginal birth. The objective of this study was to identify risk factors for PUR in order to provide prompt management.Study design: A retrospective, comparative, case-control study, including two groups of 96 patients who delivered vaginally, was conducted at the Women and Children's University Hospital in Lyon, France. Patients were selected based on data extraction from the medical records of the obstetrics and gynecology department. The first group included patients with postpartum urinary retention and the second group, without PUR, was selected randomly, respecting 1:1 matching criteria, paired according to the year of delivery and patient's age at delivery.Results: Logistic regression analysis found that instrumental delivery (OR 13.42, 95%CI [3.34;53.86], p = 0.0002), absence of spontaneous voiding before leaving the delivery room (OR 6.14, 95%CI [2.56;14.73], p < 0.0001), no intact perineum (OR 3.29, 95%CI [1.10;9.90], p = 0.03) and vulvar edema or perineal hematoma (OR 8.05, 95%CI [1.59;40.67], p = 0.01) were independent risk factors associated with PUR.Conclusion: The present study identified risk factors for PUR that should be taken into consideration as soon as delivery is over in order to implement appropriate management. Future studies are needed to assess the contribution of early systematic bladder scanning in patients with risk factors for early diagnosis of PUR

Endothelial, but not smooth muscle, peroxisome proliferator-activated receptor β/δ regulates vascular permeability and anaphylaxis.

International audienceRemodeling of quiescent vessels with increases in permeability, vasodilatation, and edema are hallmarks of inflammatory disorders. Factors involved in this type of remodeling represent potential therapeutic targets. We investigated whether the nuclear hormone receptor peroxisome proliferator-activated receptor (PPAR) β/δ, a regulator of metabolism, fibrosis, and skin homeostasis, is involved in regulation of this type of remodeling. Wild-type and various Pparb/d mutant mice were used to monitor dermal acute vascular hyperpermeability (AVH) and passive systemic anaphylaxis-induced hypothermia and edema. PPARβ/δ-dependent kinase activation and remodeling of endothelial cell-cell junctions were addressed by using human endothelial cells. AVH and dilatation of dermal microvessels stimulated by vascular endothelial growth factor A, histamine, and thrombin are severely compromised in PPARβ/δ-deficient mice. Selective deletion of the Pparb/d-encoding gene in endothelial cells in vivo similarly limits dermal AVH and vasodilatation, providing evidence that endothelial PPARβ/δ is the major player in regulating acute dermal microvessel remodeling. Furthermore, endothelial PPARβ/δ regulatory functions are not restricted to the skin vasculature because its deletion in the endothelium, but not in smooth muscle cells, also leads to reduced systemic anaphylaxis, the most severe form of allergic reaction, in which an acute vascular response plays a key role. PPARβ/δ-dependent AVH activation likely involves the activation of mitogen-activated protein kinase and Akt pathways and leads to downstream destabilization of endothelial cell-cell junctions. These results unveil not only a novel function of PPARβ/δ as a direct regulator of acute vessel permeability and dilatation but also provide evidence that antagonizing PPARβ/δ represents an important strategy to consider for moderating diseases with altered endothelial integrity, such as acute inflammatory and allergic disorders

High Efficiency Solar Cell Based on Full PVD Processed Cu(In,Ga)Se2/CdIn2S4 Heterojunction

International audienceThe original goal of our study is to synthesize by co-evaporation the phase that could be formed at the interface between polycrystalline p-Cu(In,Ga)Se2 treated with KF and n-CdS. Hence, a new buffer layer, CdIn2S4 (C24), deposited by co-evaporation is presented for the use in thin film solar cells, exhibiting device efficiencies as high as 16.2%, comparable to that obtained on a reference standard CdS-buffered device. The physico-chemical and optical properties of close to stoichiometry 400 nm-thick films of C24 show similar properties to what has been reported in the literature for single crystals. The layer stack used for solar cells is investigated by transmission electron microscopy, showing the formation of an ultrathin Cd-deficient C24 layer at the CIGSe/C24 interface, while a clear lattice match is observed at the C24/ZnO interface. Advanced electrical characterizations of the devices suggest that the output voltage and fill factor of the solar cells based on Cu(In,Ga)Se2/(PVD)C24 are limited by tunneling-enhanced recombination through extended band tail states. These results open new routes to explain the superiority of wet processes used for the junction formation compared to vacuum-based approaches

Statistical Postprocessing for Weather Forecasts: Review, Challenges, and Avenues in a Big Data World

International audienceAbstract Statistical postprocessing techniques are nowadays key components of the forecasting suites in many national meteorological services (NMS), with, for most of them, the objective of correcting the impact of different types of errors on the forecasts. The final aim is to provide optimal, automated, seamless forecasts for end users. Many techniques are now flourishing in the statistical, meteorological, climatological, hydrological, and engineering communities. The methods range in complexity from simple bias corrections to very sophisticated distribution-adjusting techniques that incorporate correlations among the prognostic variables. The paper is an attempt to summarize the main activities going on in this area from theoretical developments to operational applications, with a focus on the current challenges and potential avenues in the field. Among these challenges is the shift in NMS toward running ensemble numerical weather prediction (NWP) systems at the kilometer scale that produce very large datasets and require high-density high-quality observations, the necessity to preserve space–time correlation of high-dimensional corrected fields, the need to reduce the impact of model changes affecting the parameters of the corrections, the necessity for techniques to merge different types of forecasts and ensembles with different behaviors, and finally the ability to transfer research on statistical postprocessing to operations. Potential new avenues are also discussed