87 research outputs found
Dark Optical Lattice of Ring Traps for Cold Atoms
We propose a new geometry of optical lattice for cold atoms, namely a lattice
made of a 1D stack of dark ring traps. It is obtained through the interference
pattern of a standard Gaussian beam with a counter-propagating hollow beam
obtained using a setup with two conical lenses. The traps of the resulting
lattice are characterized by a high confinement and a filling rate much larger
than unity, even if loaded with cold atoms from a MOT. We have implemented this
system experimentally, and obtained a lattice of ring traps populated with
typically 40 atoms per site with a life time of 30 ms. Applications in
statistical physics, quantum computing and Bose-Einstein condensate dynamics
are conceivable.Comment: 4 pages, submitted to PR
Détection de facultés affaiblies par l'analyse du comportement oculaire sur des séquences vidéo
Influence des émotions sur la prise de décision chez l'enfant, l'adolescent et l'adulte (Comment le contexte socio-émotionnel et le développement des émotions contrefactuelles influencent-ils nos choix ?)
L objectif général de cette thèse est (i) d examiner l influence du contexte socio-émotionnel sur la prise de décision à risque, chez l enfant, l adolescent et l adulte (ii) et de s interroger sur la dynamique développementale des Types 1 (heuristique) et 2 (analytique) de raisonnement envisagés par les théories du double processus et de leur articulation avec la Prospect Theory. Selon nous, cette articulation permettra de mieux rendre compte de l influence des émotions sur la sensibilité aux gains et aux pertes dans la prise de décision. Dans ce contexte, nous avons d abord examiné l influence d un contexte émotionnel incident sur la sensibilité à un biais décisionnel classique, l effet du cadre de présentation, chez l adulte. Nous nous sommes intéressés à l influence du contexte émotionnel du point de vue de sa valence (positive ou négative), avant d étudier l influence d émotions spécifiques (la colère et la peur). Sur le plan de la valence, nos résultats mettent en évidence l influence des émotions positives dans la disparition de l effet du cadre, à travers la réduction de l aversion aux pertes. Les émotions plus spécifiques ont une influence différenciée sur la prise de risque, la peur tendant à l augmenter, tandis que la colère tend à la réduire. Puis, nous avons étudié l influence d émotions positives sur la sensibilité à l effet du cadre à l adolescence, période critique en termes de prise de risque. La sensibilité à l effet du cadre varie en fonction des sommes en jeu, ce qui conduit à une influence différenciée du contexte émotionnel selon cet enjeu. Nous nous sommes ensuite intéressés au développement de deux émotions intégrales au processus de prise de décision, dites également contrefactuelles (le regret et le soulagement) et à leur influence sur la volonté de reconsidérer un choix. Pour ce faire, nous avons élaboré une tâche de prise de décision induisant du regret ou du soulagement et nous avons mis en évidence un développement progressif du ressenti de ces émotions et de la capacité à les prendre en compte lors de la reconsidération d un choix antérieur. Enfin, nous avons étudié le développement du regret social et du soulagement social de l enfance à l âge adulte, à travers un paradigme de compétition avec un pair. Le contexte de compétition semble biaiser l évaluation rationnelle du regret et du soulagement à l adolescence, certaines situations étant perçues comme plus désirables par rapport à un contexte de jeu individuel. Ces résultats sont discutés en lien avec la Prospect Theory, puisque la sensibilité aux gains et aux pertes semble modulée de façon distincte, à différents stades du développement, par le contexte émotionnel.The general goal of this thesis was to study (i) the influence of different socio-emotional contexts on decision-making under risk, in children, adolescents and adults and (ii) the developmental dynamics of the Types 1 (heuristic) and 2 (analytic) of reasoning within the framework of the Dual Process theories, and their articulation with the Prospect Theory. According to us, a better articulation between these two theories could account more efficiently of the influence of emotions on reward and punishment sensitivity in decision-making. Therefore, we first examined the influence of an incidental emotional context on the framing effect - a classical bias in decision-making - on adult participants. We started by studying the influence of the valence of the emotions (positive or negative) and then the influence of different specific emotions (anger and fear) on this bias. Our results revealed that the participants were no longer affected by the framing effect following an exposure to a positive emotional context, due to a decrease of risk aversion in the loss frame. The two negative emotions we considered had opposite effects on risk taking: fear tended to increase risk taking, whereas anger tended to decrease it. In a follow-up study, we investigated the influence of incidental positive emotions on the framing effect during adolescence, a critical period for risk taking. In adolescents, the framing effect was modulated by the amount of the outcome at stake, and the emotional context had different impact on this bias depending of the amount of the outcome considered. Then, we examined the development of two integral (and counterfactual) emotions, regret and relief, and how these emotions affect our willingness to reconsider a choice. We elaborated a new gambling task and we manipulated the outcome obtained by the participants to induce regret or relief. This study provided evidence that the ability to experience regret and relief and the ability to take them into consideration continue to develop during late childhood and adolescence. We finally studied the development of social regret and relief from late childhood to adulthood, using a situation of social competition (playing against a playmate). This socio-emotional context seems to bias the rational evaluation of regret and relief in adolescence, as some situations are evaluated as more desirable, as compared to the same situations in a context of individual game. These results are discussed in light of the Prospect theory, as reward and punishment sensitivity seems to be differently modulated by socio-emotional context, at each developmental stage.PARIS5-Bibliotheque electronique (751069902) / SudocSudocFranceF
Structural and functional multiplatform MRI series of a single human volunteer over more than fifteen years
We present MRI data from a single human volunteer consisting in over 599 multi-contrast MR images
(T1-weighted, T2-weighted, proton density, fuid-attenuated inversion recovery, T2* gradient-echo,
difusion, susceptibility-weighted, arterial-spin labelled, and resting state BOLD functional connectivity
imaging) acquired in over 73 sessions on 36 diferent scanners (13 models, three manufacturers) over
the course of 15+ years (cf. Data records). Data included planned data collection acquired within the
Consortium pour l’identifcation précoce de la maladie Alzheimer - Québec (CIMA-Q) and Canadian
Consortium on Neurodegeneration in Aging (CCNA) studies, as well as opportunistic data collection
from various protocols. These multiple within- and between-centre scans over a substantial time course
of a single, cognitively healthy volunteer can be useful to answer a number of methodological questions
of interest to the community
MHC Class I Endosomal and Lysosomal Trafficking Coincides with Exogenous Antigen Loading in Dendritic Cells
BACKGROUND: Cross-presentation by dendritic cells (DCs) is a crucial prerequisite for effective priming of cytotoxic T-cell responses against bacterial, viral and tumor antigens; however, this antigen presentation pathway remains poorly defined. METHODOLOGY/PRINCIPAL FINDINGS: In order to develop a comprehensive understanding of this process, we tested the hypothesis that the internalization of MHC class I molecules (MHC-I) from the cell surface is directly involved in cross-presentation pathway and the loading of antigenic peptides. Here we provide the first examination of the internalization of MHC-I in DCs and we demonstrate that the cytoplasmic domain of MHC-I appears to act as an addressin domain to route MHC-I to both endosomal and lysosomal compartments of DCs, where it is demonstrated that loading of peptides derived from exogenously-derived proteins occurs. Furthermore, by chasing MHC-I from the cell surface of normal and transgenic DCs expressing mutant forms of MHC-I, we observe that a tyrosine-based endocytic trafficking motif is required for the constitutive internalization of MHC-I molecules from the cell surface into early endosomes and subsequently deep into lysosomal peptide-loading compartments. Finally, our data support the concept that multiple pathways of peptide loading of cross-presented antigens may exist depending on the chemical nature and size of the antigen requiring processing. CONCLUSIONS/SIGNIFICANCE: We conclude that DCs have 'hijacked' and adapted a common vacuolar/endocytic intracellular trafficking pathway to facilitate MHC I access to the endosomal and lysosomal compartments where antigen processing and loading and antigen cross-presentation takes place
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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Complete vertebrate mitogenomes reveal widespread repeats and gene duplications
Abstract: Background: Modern sequencing technologies should make the assembly of the relatively small mitochondrial genomes an easy undertaking. However, few tools exist that address mitochondrial assembly directly. Results: As part of the Vertebrate Genomes Project (VGP) we develop mitoVGP, a fully automated pipeline for similarity-based identification of mitochondrial reads and de novo assembly of mitochondrial genomes that incorporates both long (> 10 kbp, PacBio or Nanopore) and short (100–300 bp, Illumina) reads. Our pipeline leads to successful complete mitogenome assemblies of 100 vertebrate species of the VGP. We observe that tissue type and library size selection have considerable impact on mitogenome sequencing and assembly. Comparing our assemblies to purportedly complete reference mitogenomes based on short-read sequencing, we identify errors, missing sequences, and incomplete genes in those references, particularly in repetitive regions. Our assemblies also identify novel gene region duplications. The presence of repeats and duplications in over half of the species herein assembled indicates that their occurrence is a principle of mitochondrial structure rather than an exception, shedding new light on mitochondrial genome evolution and organization. Conclusions: Our results indicate that even in the “simple” case of vertebrate mitogenomes the completeness of many currently available reference sequences can be further improved, and caution should be exercised before claiming the complete assembly of a mitogenome, particularly from short reads alone
Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study
Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe
Inhibition et émotion (conservations, fonctions exécutives et hédonie)
PARIS5-BU Saints-Pères (751062109) / SudocBOULOGNE-BU Psych. Henri Pieron (920125201) / SudocSudocFranceF
Inhibitory control as a core mechanism for cognitive development and learning at school.
International audienc
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