Using high-resolution quantitative mapping of R1 as an index of cortical myelination

A fundamental tenet of neuroscience is that cortical functional differentiation is related to the cross-areal differences in cyto-, receptor-, and myeloarchitectonics that are observed in ex-vivo preparations. An ongoing challenge is to create noninvasive magnetic resonance (MR) imaging techniques that offer sufficient resolution, tissue contrast, accuracy and precision to allow for characterization of cortical architecture over an entire living human brain. One exciting development is the advent of fast, high-resolution quantitative mapping of basic MR parameters that reflect cortical myeloarchitecture. Here, we outline some of the theoretical and technical advances underlying this technique, particularly in terms of measuring and correcting for transmit and receive radio frequency field inhomogeneities. We also discuss new directions in analytic techniques, including higher resolution reconstructions of the cortical surface. We then discuss two recent applications of this technique. The first compares individual and group myelin maps to functional retinotopic maps in the same individuals, demonstrating a close relationship between functionally and myeloarchitectonically defined areal boundaries (as well as revealing an interesting disparity in a highly studied visual area). The second combines tonotopic and myeloarchitectonic mapping to localize primary auditory areas in individual healthy adults, using a similar strategy as combined electrophysiological and post-mortem myeloarchitectonic studies in non-human primates.

A fully-automatic caudate nucleus segmentation of brain MRI: application in volumetric analysis of pediatric attention-deficit/hyperactivity disorder

Background Accurate automatic segmentation of the caudate nucleus in magnetic resonance images (MRI) of the brain is of great interest in the analysis of developmental disorders. Segmentation methods based on a single atlas or on multiple atlases have been shown to suitably localize caudate structure. However, the atlas prior information may not represent the structure of interest correctly. It may therefore be useful to introduce a more flexible technique for accurate segmentations. Method We present Cau-dateCut: a new fully-automatic method of segmenting the caudate nucleus in MRI. CaudateCut combines an atlas-based segmentation strategy with the Graph Cut energy-minimization framework. We adapt the Graph Cut model to make it suitable for segmenting small, low-contrast structures, such as the caudate nucleus, by defining new energy function data and boundary potentials. In particular, we exploit information concerning the intensity and geometry, and we add supervised energies based on contextual brain structures. Furthermore, we reinforce boundary detection using a new multi-scale edgeness measure. Results We apply the novel CaudateCut method to the segmentation of the caudate nucleus to a new set of 39 pediatric attention-deficit/hyperactivity disorder (ADHD) patients and 40 control children, as well as to a public database of 18 subjects. We evaluate the quality of the segmentation using several volumetric and voxel by voxel measures. Our results show improved performance in terms of segmentation compared to state-of-the-art approaches, obtaining a mean overlap of 80.75%. Moreover, we present a quantitative volumetric analysis of caudate abnormalities in pediatric ADHD, the results of which show strong correlation with expert manual analysis. Conclusion CaudateCut generates segmentation results that are comparable to gold-standard segmentations and which are reliable in the analysis of differentiating neuroanatomical abnormalities between healthy controls and pediatric ADHD.

Contemporary approach to neurologic prognostication of coma after cardiac arrest.

Coma after cardiac arrest (CA) is an important cause of admission to the ICU. Prognosis of post-CA coma has significantly improved over the past decade, particularly because of aggressive postresuscitation care and the use of therapeutic targeted temperature management (TTM). TTM and sedatives used to maintain controlled cooling might delay neurologic reflexes and reduce the accuracy of clinical examination. In the early ICU phase, patients' good recovery may often be indistinguishable (based on neurologic examination alone) from patients who eventually will have a poor prognosis. Prognostication of post-CA coma, therefore, has evolved toward a multimodal approach that combines neurologic examination with EEG and evoked potentials. Blood biomarkers (eg, neuron-specific enolase [NSE] and soluble 100-β protein) are useful complements for coma prognostication; however, results vary among commercial laboratory assays, and applying one single cutoff level (eg, > 33 μg/L for NSE) for poor prognostication is not recommended. Neuroimaging, mainly diffusion MRI, is emerging as a promising tool for prognostication, but its precise role needs further study before it can be widely used. This multimodal approach might reduce false-positive rates of poor prognosis, thereby providing optimal prognostication of comatose CA survivors. The aim of this review is to summarize studies and the principal tools presently available for outcome prediction and to describe a practical approach to the multimodal prognostication of coma after CA, with a particular focus on neuromonitoring tools. We also propose an algorithm for the optimal use of such multimodal tools during the early ICU phase of post-CA coma.

Monnaie, citoyenneté et globalisation financière. Les citoyens entre protection sociale et promesses de la capitalisation boursière

La monnaie a été étudiée par des économistes hétérodoxes, des sociologues et des historiens qui ont souligné ses rapports à l'ordre collectif, mais elle n'est que rarement analysée sous l'angle de la citoyenneté. Notre thèse propose une réflexion théorique sur quatre types de fonctions (politique, symbolique, socioéconomique et psychoaffective) qui permettent à la monnaie de jouer un rôle de médiation de la citoyenneté. A partir d'une perspective qui combine les apports de l'économie politique internationale et de l'école de la régulation, nous montrons que cette médiation ne mobilise pas seulement des mécanismes sociopolitiques nationaux, mais aussi des mécanismes internationaux qui rétroagissent sur la sphère domestique des États et affectent leur capacité à définir leur régime de citoyenneté. Cette relation est analysée dans le contexte de l'institutionnalisation du système monétaire international de Bretton Woods (1944) et du développement de la globalisation financière depuis les années 1970. Si la monnaie a été mise au service d'un principe de protection des droits sociaux des citoyens contre les pressions financières extérieures après la Seconde guerre mondiale, elle contribue aujourd'hui à l'ouverture de la sphère domestique des Etats aux flux de capitaux transnationaux et à la création d'un ordre politique et juridique favorable aux droits des investisseurs. Cette dynamique est impulsée par l'essor de nouveaux intermédiaires financiers (notamment les agences de notation et les investisseurs institutionnels) et l'émergence concomitante d'une nouvelle forme d'Etat légitimée à partir d'un discours politique néolibéral insistant sur la quête de compétitivité, la réduction de la protection sociale et la responsabilisation individuelle. Elle se traduit par la privatisation des régimes de retraite et le développement des politiques d'éducation financière qui incitent les citoyens à se comporter en « preneurs de risques » actifs et responsables, assurant eux-mêmes leur sécurité économique à travers le placement de leur épargne retraite sur les marchés financiers. Nous soulignons toutefois les difficultés institutionnelles, cognitives et socioéconomiques qui rendent cette transformation de la citoyenneté contradictoire et problématique. Money has been studied by heterodox economists, sociologists and historians who stressed its relationship to collective order. However, it has hardly been analysed from the viewpoint of its relationship to citizenship. We propose a theoretical account of four types of functions (political, symbolic, socioeconomic and psychoaffective) enabling money to operate as a mediation of citizenship. From a perspective that combines the contributions of international political economy and the regulation school, we show that this mediation mobilises not only national sociopolitical mechanisms, but also international mechanisms which feed back on the domestic sphere of states and affect their capacity to define their regime of citizenship. This relationship is analysed in the context of the institutionalisation of the international monetary system of Bretton Woods (1944) and the development of financial globalization since the 1970s. If money has served to protect the social rights of citizens against external financial pressures after the Second World War, today it contributes to the opening of the domestic sphere of states to transnational capital flows and to the creation of a political and legal order favorable to the rights of investors. This dynamic is driven by the rise of new financial intermediaries (in particular rating agencies and institutional investisors) and the simultaneous emergence of a new form of state legitimized from a neoliberal political discourse emphasizing the quest for competitiveness, reduced social protection and individual responsibilization. It results in the privatization of pension systems and the development of policies of financial education that encourage citizens to behave as active and responsible « risk takers », ensuring their own economic security through the investment of their savings retirement on financial markets. However, we emphasize the institutional, cognitive and socioeconomic difficulties that make this transformation of citizenship contradictory and problematic. - Money has been studied by heterodox economists, sociologists and historians who stressed its relationship to collective order. However, it has hardly been analysed from the viewpoint of its relationship to citizenship. We propose a theoretical account of four types of functions (political, symbolic, socioeconomic and psychoaffective) enabling money to operate as a mediation of citizenship. From a perspective that combines the contributions of international political economy and the regulation school, we show that this mediation mobilises not only national sociopolitical mechanisms, but also international mechanisms which feed back on the domestic sphere of states and affect their capacity to define their regime of citizenship. This relationship is analysed in the context of the institutionalisation of the international monetary system of Bretton Woods (1944) and the development of financial globalization since the 1970s. If money has served to protect the social rights of citizens against external financial pressures after the Second World War, today it contributes to the opening of the domestic sphere of states to transnational capital flows and to the creation of a political and legal order favorable to the rights of investors. This dynamic is driven by the rise of new financial intermediaries (in particular rating agencies and institutional investisors) and the simultaneous emergence of a new form of state legitimized from a neoliberal political discourse emphasizing the quest for competitiveness, reduced social protection and individual responsibilization. It results in the privatization of pension systems and the development of policies of financial education that encourage citizens to behave as active and responsible « risk takers », ensuring their own economic security through the investment of their savings retirement on financial markets. However, we emphasize the institutional, cognitive and socioeconomic difficulties that make this transformation of citizenship problematic.

Antiferromagnetic exchange interactions from hybrid density functional theory

A hybrid theory which combines the full nonlocal ¿exact¿ exchange interaction with the local spin-density approximation of density-functional theory is shown to lead to marked improvement in the description of antiferromagnetically coupled systems. Semiquantitative agreement with experiment is found for the magnitude of the coupling constant in La2CuO4, KNiF3, and K2NiF4. The magnitude of the unpaired spin population on the metal site is in excellent agreement with experiment for La2CuO4.

Optimization of snowmaking in high mountains ski resort

Ski resorts are deploying more and more systems of artificial snow. These tools are necessary to ensure an important economic activity for the high alpine valleys. However, artificial snow raises important environmental issues that can be reduced by an optimization of its production. This paper presents a software prototype based on artificial intelligence to help ski resorts better manage their snowpack. It combines on one hand a General Neural Network for the analysis of the snow cover and the spatial prediction, with on the other hand a multiagent simulation of skiers for the analysis of the spatial impact of ski practice. The prototype has been tested on the ski resort of Verbier (Switzerland).

Réhabilitation accélérée multimodate postcésarienne, la somme de toutes les astuces [Fast-track multimodal rehabilitation after cesarean, the sum of all tricks].

Fast-track multimodal rehabilitation after cesarean, the sum of all tricks Fast-track multimodal rehabilitation after caesarean is an interdisciplinary concept allowing an accelerated return to normal physiology. Fast-track rehabilitation combines minimising surgical trauma, regional anaesthesia and active management of pain control, minimally invasive postoperative care while promoting return to autonomy.

Dermatite atopique de l'enfant: principes généraux de la prise en charge [Atopic dermatitis in children: general principles of management].

Atopic dermatitis is the most frequent dermatosis in childhood. Numerous studies underscored the central role of skin barrier alterations in the pathogenesis of the inflammatory skin lesions. The management of atopic dermatitis has to be multidimensional. It combines among others some daily local care and a sporadic topical anti-inflammatory treatment during the acute flare-ups. The objective of this article is to summarize, in light of the recent European guidelines, the general principles of management of atopic dermatitis, for the general practitioner.

Dépistage néonatal systématique de la mucoviscidose en Suisse: dès janvier 2011 [Implementation of the neonatal cystic fibrosis screening program in Switzerland: beginning January 2011].

The diagnosis of cystic fibrosis (CF) is often delayed because of the nonspecificity of a wide variety of clinical symptoms at disease onset. Newborn screening for CF has been advocated to reduce delays in diagnosis, facilitating preventive care for early respiratory and nutritional involvement. According to American and European consensus and experience of existing programs, a Swiss Nationwide Cystic Fibrosis Newborn Screening Program started in January 2011. Screening strategy combines two steps: an immunoreactive trypsinogen assay and DNA mutation analysis in dried blood samples at day 4 (Guthrie cards).

Characterization of a MexAB-OprM efflux system necessary for productive metabolism of Pseudomonas azelaica HBP1 on 2-hydroxybiphenyl.

Pseudomonas azelaica HBP1 is one of the few bacteria known to completely mineralize the biocide and toxic compound 2-hydroxybiphenyl (2-HBP), but the mechanisms of its tolerance to the toxicity are unknown. By transposon mutant analysis and screening for absence of growth on water saturating concentrations of 2-HBP (2.7 mM) we preferentially found insertions in three genes with high homology to the mexA, mexB, and oprM efflux system. Mutants could grow at 2-HBP concentrations below 100 μM but at lower growth rates than the wild-type. Exposure of the wild-type to increasing 2-HBP concentrations resulted in acute cell growth arrest and loss of membrane potential, to which the cells adapt after a few hours. By using ethidium bromide (EB) as proxy we could show that the mutants are unable to expel EB effectively. Inclusion of a 2-HBP reporter plasmid revealed that the wild-type combines efflux with metabolism at all 2-HBP concentrations, whereas the mutants cannot remove the compound and arrest metabolism at concentrations above 24 μM. The analysis thus showed the importance of the MexAB-OprM system for productive metabolism of 2-HBP.

"Suddenly I get into the zone": Examining discontinuities and nonlinear changes in flow experiences at work

Work-related flow is defined as a sudden and enjoyable merging of action and awareness that represents a peak experience in the daily lives of workers. Employees" perceptions of challenge and skill and their subjective experiences in terms of enjoyment, interest and absorption were measured using the experience sampling method, yielding a total of 6981 observations from a sample of 60 employees. Linear and nonlinear approaches were applied in order to model both continuous and sudden changes. According to the R2, AICc and BIC indexes, the nonlinear dynamical systems model (i.e. cusp catastrophe model) fit the data better than the linear and logistic regression models. Likewise, the cusp catastrophe model appears to be especially powerful for modelling those cases of high levels of flow. Overall, flow represents a nonequilibrium condition that combines continuous and abrupt changes across time. Research and intervention efforts concerned with this process should focus on the variable of challenge, which, according to our study, appears to play a key role in the abrupt changes observed in work-related flow.

Genèse de la recherche académique nord-américaine sur les expériences de mort imminente. L'exemple des recherches menées par Russel Noyes, psychiatre, de 1967 à 1977

La présente thèse analyse les facteurs expliquant l'attrait académique pour la Near-Death Experience (NDE) aux Etats-Unis. À travers l'étude d'un acteur clé, Russell Noyés, la thèse démontre que l'expérience de mort imminente est devenue pertinente grâce aux psychiatres et aux psychologues qui lui ont octroyé une qualité clinique et thérapeutique. Afin de reconstruire les fondements académiques de l'intérêt pour l'étude de la mort, de l'expérience de la mort et de la mort imminente en psychiatrie dans les années 1960-70, la méthode employée est celle d'une enquête historique qui combine une approche empirique avec une génétique de récit. - The dissertation analyses the factors explaining the emergence of the Near- Death Experience (NDE) as a research topic in the disciplines of psychology and psychiatry in the United States. The study of a key actor, Russell Noyes, will demonstrate how the experience of near-death became relevant through the work of psychiatrists and psychologists who attributed a clinical and therapeutical quality to it. In order to retrace the academic foundations of the research on death, the experience of dying and near-death, during the 60s and 70s, this dissertation applies a historical method, which combines an empirical approach with a genetic of narratives.

La délinquance des étrangers : criminalité, récidive et les facteurs influençant le retour en prison

Résumé : La délinquance des étrangers se situe depuis quelques années au milieu de beaucoup de débats politiques. En même temps, la récidive constitue l'un des sujets d'étude classiques de la criminologie. Cette recherche combine ces deux phénomènes en s'intéressant aux causes de la délinquance et de l'éventuelle récidive d'un échantillon d'étrangers incarcérés en Suisse. Le cadre théorique repose sur une revue approfondie de la littérature scientifique sur la délinquance des étrangers ainsi que sur les facteurs influençant la récidive. Ces revues ont conduit à l'élaboration d'une série d'hypothèses qui ont été testées dans la partie empirique du travail. Cette dernière comprend l'étude des 500 dossiers des étrangers libérés des Etablissements pénitentiaires de la Plaine de l'Orbe (EPO, canton de Vaud, Suisse) entre 1995 et 1999, ainsi que le suivi de ces personnes, avec l'aide des données fournies par l'Office fédéral de la statistique, afin d'établir si elles avaient récidivé durant les cinq années postérieures à leur libération. Elle comprend également l'analyse de 125 entretiens conduits auprès des détenus des EPO entre 2005 et 2006 dont le but était d'établir, entre autres, leur perception subjective sur les causes de la délinquance et de la récidive. Les résultats indiquent un taux de récidive d'environ 30%. En outre, ils corroborent l'influence sur la récidive des facteurs identifiés par les recherches précédentes bien que, vu les particularités de l'échantillon étudié, certains de ces facteurs -tel que l'âge à la première condamnation ou l'âge à la sortie de prison-, présentent des divergences. En outre, l'analyse des entretiens a permis l'élaboration d'une nouvelle classification des causes de la récidive. Finalement, la recherche permet une connaissance plus approfondie des causes de l'implication dans la délinquance de la population de référence. The delinquency of the foreigners: criminality, recidivism and the factors that influence to the return to prison Abstract : The foreigners' delinquency is today in the middle of political debates. Moreover, recidivism is one of the classical subjects studied in criminology. The present research combines these two phenomena by studying the causes of foreigners' delinquency and recidivism. With the purpose of doing this research, a theoretical framework on the criminality of foreigners has been established through an extensive review of research literature on this subject as well as on the factors influencing recidivism. These reviews have allowed the establishment of a series of hypotheses that have been tested in the empirical part of the study. This empirical research includes the study of 500 cases of all foreigners released from the Penitentiary Establishment of the Plaine de l'Orbe (EPO, in the Vaud region) between 1995 and 1999. This population was then followed-up by means of data provided by the Swiss Federal Office of Statistics in order to know whether they had recidivated during the five years following their release. The empirical study also includes the analysis of interviews conducted with 125 inmates of EPO between 2005 and 2006 to determine what are, in the opinion of the inmates interviewed, the causes of recidivism and the causes of crime. The results show a recidivism rate of approximately 30%. Furthermore, the factors which, according to research analyzed, influence recidivism, have also been related to the recidivism of our sample. However, due to the fact that the sample studied consists of foreigners, some factors, such as age of the first conviction or age of release of prison, show some differences with respect to the literature. Finally, the information obtained from the interviews has allowed the establishment of a new classification on the causes of recidivism, and to get a deeper knowledge of the causes of crime involvement of the population studied.

Targeting Cancer Stem-like Cells as an Approach to Defeating Cellular Heterogeneity in Ewing Sarcoma.

Plasticity in cancer stem-like cells (CSC) may provide a key basis for cancer heterogeneity and therapeutic response. In this study, we assessed the effect of combining a drug that abrogates CSC properties with standard-of-care therapy in a Ewing sarcoma family tumor (ESFT). Emergence of CSC in this setting has been shown to arise from a defect in TARBP2-dependent microRNA maturation, which can be corrected by exposure to the fluoroquinolone enoxacin. In the present work, primary ESFT from four patients containing CD133(+) CSC subpopulations ranging from 3% to 17% of total tumor cells were subjected to treatment with enoxacin, doxorubicin, or both drugs. Primary ESFT CSC and bulk tumor cells displayed divergent responses to standard-of-care chemotherapy and enoxacin. Doxorubicin, which targets the tumor bulk, displayed toxicity toward primary adherent ESFT cells in culture but not to CSC-enriched ESFT spheres. Conversely, enoxacin, which enhances miRNA maturation by stimulating TARBP2 function, induced apoptosis but only in ESFT spheres. In combination, the two drugs markedly depleted CSCs and strongly reduced primary ESFTs in xenograft assays. Our results identify a potentially attractive therapeutic strategy for ESFT that combines mechanism-based targeting of CSC using a low-toxicity antibiotic with a standard-of-care cytotoxic drug, offering immediate applications for clinical evaluation.

Graph theory reveals dysconnected hubs in 22q11DS and altered nodal efficiency in patients with hallucinations.

Schizophrenia is postulated to be the prototypical dysconnection disorder, in which hallucinations are the core symptom. Due to high heterogeneity in methodology across studies and the clinical phenotype, it remains unclear whether the structural brain dysconnection is global or focal and if clinical symptoms result from this dysconnection. In the present work, we attempt to clarify this issue by studying a population considered as a homogeneous genetic sub-type of schizophrenia, namely the 22q11.2 deletion syndrome (22q11.2DS). Cerebral MRIs were acquired for 46 patients and 48 age and gender matched controls (aged 6-26, respectively mean age = 15.20 ± 4.53 and 15.28 ± 4.35 years old). Using the Connectome mapper pipeline (connectomics.org) that combines structural and diffusion MRI, we created a whole brain network for each individual. Graph theory was used to quantify the global and local properties of the brain network organization for each participant. A global degree loss of 6% was found in patients' networks along with an increased Characteristic Path Length. After identifying and comparing hubs, a significant loss of degree in patients' hubs was found in 58% of the hubs. Based on Allen's brain network model for hallucinations, we explored the association between local efficiency and symptom severity. Negative correlations were found in the Broca's area (p < 0.004), the Wernicke area (p < 0.023) and a positive correlation was found in the dorsolateral prefrontal cortex (DLPFC) (p < 0.014). In line with the dysconnection findings in schizophrenia, our results provide preliminary evidence for a targeted alteration in the brain network hubs' organization in individuals with a genetic risk for schizophrenia. The study of specific disorganization in language, speech and thought regulation networks sharing similar network properties may help to understand their role in the hallucination mechanism.