Analysis of a finite volume element method for the Stokes problem

In this paper we propose a stabilized conforming finite volume element method for the Stokes equations. On stating the convergence of the method, optimal a priori error estimates in different norms are obtained by establishing the adequate connection between the finite volume and stabilized finite element formulations. A superconvergence result is also derived by using a postprocessing projection method. In particular, the stabilization of the continuous lowest equal order pair finite volume element discretization is achieved by enriching the velocity space with local functions that do not necessarily vanish on the element boundaries. Finally, some numerical experiments that confirm the predicted behavior of the method are provided.

Prevalence of and potential influencing factors for alcohol dependence in europe.

Alcohol use disorders (AUDs), and alcohol dependence (AD) in particular, are prevalent and associated with a large burden of disability and mortality. The aim of this study was to estimate prevalence of AD in the European Union (EU), Iceland, Norway, and Switzerland for the year 2010, and to investigate potential influencing factors. The 1-year prevalence of AD in the EU was estimated at 3.4% among people 18-64 years of age in Europe (women 1.7%, men 5.2%), resulting in close to 11 million affected people. Taking into account all people of all ages, AD, abuse and harmful use resulted in an estimate of 23 million affected people. Prevalence of AD varied widely between European countries, and was significantly impacted by drinking cultures and social norms. Correlations with level of drinking and other drinking variables and with major known outcomes of heavy drinking, such as liver cirrhosis or injury, were moderate. These results suggest a need to rethink the definition of AUDs.

Neither Bad Apple nor Bad Barrel: How the Societal Context Impacts Unethical Behavior in Organizations

Every time another corporate scandal captures media headlines, the 'bad apple vs. bad barrel' discussion starts anew. Yet this debate overlooks the influence of the broader societal context on organizational behavior. In this article, we argue that misbehaviors of organizations (the 'barrels') and their members (the 'apples') cannot be addressed properly without a clear understanding of their broader context (the 'larder'). Whereas previously, a strong societal framework dampened the practical application of the Homo economicus concept (business actors as perfectly rational and egocentric utility-maximizing agents without any moral concern), specialization, individualization and globalization led to a business world disembedded from broader societal norms. This emancipated business world promotes a literal interpretation of Homo economicus among business organizations and their members. Consequently, we argue that the first step toward 'healthier' apples and barrels is to sanitize the larder, that is, adapt the framework in which organizations and their members evolve.Chaque fois qu'un nouveau scandale fait la une des médias, la question de savoir si le problème se situe au niveau des individus (des 'pommes isolées') ou au niveau des organisations (les 'caisses de pommes') refait surface. Ce débat tend néanmoins à sous-estimer l'influence du contexte sociétal plus large sur le comportement dans les organisations. Dans cet article, nous soutenons l'idée que les scandales éthiques dans les organisations ou parmi leurs membres ne peuvent être compris correctement sans une vision plus précise de leur contexte plus large (la 'cave à pommes'). Si dans le passé un contexte sociétal fort permettait d'adoucir les applications pratiques de l'Homo economicus (qui considère l'acteur économique comme un agent parfaitement rationnel et égocentrique cherchant à maximiser son utilité sans réflexion morale), l'individualisation et la globalisation ont conduit à un monde économique désencastré et déconnecté des normes sociales plus larges. Ce monde économique autonome promouvoit une interprétation littérale de l'Homo economicus parmi les entreprises et leurs employés. Il en résulte que le premier pas vers des pommes moins pourries passe par un assainissement de la cave, c'est-à-dire l'adoption d'un cadre socio-normatif qui permet un recadrage du contexte dans lequel les organisations économiques et leurs acteurs agissent.

Pale and dark reddish melanic tawny owls differentially regulate the level of blood circulating POMC prohormone in relation to environmental conditions.

Knowledge of the hormonal pathway controlling genotype-specific norms of reaction would shed light on the ecological factors to which each genotype is adapted. Environmentally mediated changes in the sign and magnitude of covariations between heritable melanin-based colouration and fitness components are frequent, revealing that extreme melanin-based phenotypes can display different physiological states depending on the environment. Yet, the hormonal mechanism underlying this phenomenon is poorly understood. One novel hypothesis proposes that these covariations stem from pleiotropic effects of the melanocortin system. Melanocortins are post-translationally modified bioactive peptides derived from the POMC prohormone that are involved in melanogenesis, anti-inflammation, energy homeostasis and stress responses. Thus, differential regulation of fitness components in relation to environmental factors by pale and dark melanic individuals may be due to colour-specific regulation of the POMC prohormone. Accordingly, we found that the degree of reddish melanic colouration was negatively correlated with blood circulating levels of the POMC prohormone in female tawny owls (Strix aluco) rearing a brood for which the size was experimentally reduced, but not when enlarged, and in females located in rich but not in poor territories. Our findings support the hypothesis that the widespread links between melanin-based colouration and fitness components may be mediated, at least in part, by the melanocortin system.

Magnetic resonance imaging determinants of intraindividual variability in the elderly: combined analysis of grey and white matter.

Elderly individuals display a rapid age-related increase in intraindividual variability (IIV) of their performances. This phenomenon could reflect subtle changes in frontal lobe integrity. However, structural studies in this field are still missing. To address this issue, we computed an IIV index for a simple reaction time (RT) task and performed magnetic resonance imaging (MRI) including voxel based morphometry (VBM) and the tract based spatial statistics (TBSS) analysis of diffusion tensor imaging (DTI) in 61 adults aged from 22 to 88 years. The age-related IIV increase was associated with decreased fractional anisotropy (FA) as well as increased radial (RD) and mean (MD) diffusion in the main white matter (WM) fiber tracts. In contrast, axial diffusion (AD) and grey matter (GM) densities did not show any significant correlation with IIV. In multivariate models, only FA has an age-independent effect on IIV. These results revealed that WM but not GM changes partly mediated the age-related increase of IIV. They also revealed that the association between WM and IIV could not be only attributed to the damage of frontal lobe circuits but concerned the majority of interhemispheric and intrahemispheric corticocortical connections.

Plasticity in sex allocation in the plant Mercurialis annua is greater for hermaphrodites sampled from dimorphic than from monomorphic populations.

Plants are notoriously variable in gender, ranging in sex allocation from purely male through hermaphrodite to purely female. This variation can have both a genetic and an adaptive plastic component. In gynodioecious species, where females co-occur with hermaphrodites, hermaphrodites tend to shift their allocation towards greater maleness when growing under low-resource conditions, either as a result of hermaphrodites shifting away from an expensive female function, or because of enhanced siring advantages in the presence of females. Similarly, in the androdioecious plant Mercurialis annua, where hermaphrodites co-exist with males, hermaphrodites also tend to enhance their relative male allocation under low-resource conditions. Here, we ask whether this response differs between hermaphrodites that have been evolving in the presence of males, in a situation analogous to that supposed for gynodioecious populations, vs. those that have been evolving in their absence. We grew hermaphrodites of M. annua from populations in which males were either present or absent under different levels of nutrient availability and compared their reaction norms. We found that, overall, hermaphrodites from populations with males tended to be more female than those from populations lacking males. Importantly, hermaphrodites' investment in pollen and seed production was more plastic when they came from populations with males than without them, reducing their pollen production at low resource availability and increasing their seed production at high resource availability. These results are consistent with the hypothesis that plasticity in sex allocation is enhanced in hermaphrodites that have likely been exposed to variation in mating opportunities due to fluctuations in the frequency of co-occurring males.

Confirmation of functional zones within the human subthalamic nucleus: patterns of connectivity and sub-parcellation using diffusion weighted imaging.

The subthalamic nucleus (STN) is a small, glutamatergic nucleus situated in the diencephalon. A critical component of normal motor function, it has become a key target for deep brain stimulation in the treatment of Parkinson's disease. Animal studies have demonstrated the existence of three functional sub-zones but these have never been shown conclusively in humans. In this work, a data driven method with diffusion weighted imaging demonstrated that three distinct clusters exist within the human STN based on brain connectivity profiles. The STN was successfully sub-parcellated into these regions, demonstrating good correspondence with that described in the animal literature. The local connectivity of each sub-region supported the hypothesis of bilateral limbic, associative and motor regions occupying the anterior, mid and posterior portions of the nucleus respectively. This study is the first to achieve in-vivo, non-invasive anatomical parcellation of the human STN into three anatomical zones within normal diagnostic scan times, which has important future implications for deep brain stimulation surgery.

Sexual protection behavior in HIV-positive gay men: testing a modified information-motivation-behavioral skills model.

This study on determinants of sexual protection behavior among HIV-positive gay men used the empirically tested information-motivation-behavioral skills (IMB) model. HIV-specific variables were added to the model to determine factors decisive for condom use with steady and casual partners. Data were collected using an anonymous, standardized self-administered questionnaire. Study participants were recruited at HIV outpatient clinics associated with the Eurosupport Study Group and the Swiss HIV Cohort Study. To identify factors associated with condom use, backward elimination regression analyses were performed. Overall, 838 HIV-infected gay men from 14 European countries were included in this analysis. About 53% of them reported at least one sexual contact with a steady partner; 62.5% had sex with a casual partner during the last 6 months. Forty-three percent always used condoms with steady partners and 44% with casual partners. High self-efficacy and subjective norms in favor of condom-use were associated with increased condom use with casual and steady partners, whereas feeling depressed was associated with decreased condom use with casual partners. Condoms were used less often with HIV-positive partners. Self-efficacy as an important behavioral skill to perform protection behavior was influenced by lower perceived vulnerability, higher subjective norms, and more positive safer sex attitudes. The IMB-model constructs appeared to be valid; however, not all the model predictors could be determined as hypothesized. Besides the original IMB constructs, HIV-specific variables, including sexual partners' serostatus and mental health, explained condom use. Such factors should be considered in clinical interventions to promote "positive prevention."

Targetting of the ventro-intermediate nucleus using ultra-high field (7T) MRI for gamma knife surgery purposes: A pilot in vivo study on healthy subjects.

INTRODUCTION: Gamma Knife surgery (GKS) is a non-invasive neurosurgical stereotactic procedure, increasingly used as an alternative to open functional procedures. This includes targeting of the ventro-intermediate nucleus of the thalamus (e.g. Vim) for tremor. We currently perform an indirect targeting, as the Vim is not visible on current 3Tesla MRI acquisitions. Our objective was to enhance anatomic imaging (aiming at refining the precision of anatomic target selection by direct visualisation) in patients treated for tremor with Vim GKS, by using high field 7T MRI. MATERIALS AND METHODSH: Five young healthy subjects were scanned on 3 (T1-w and diffusion tensor imaging) and 7T (high-resolution susceptibility weighted images (SWI)) MRI in Lausanne. All images were further integrated for the first time into the Gamma Plan Software(®) (Elekta Instruments, AB, Sweden) and co-registered (with T1 was a reference). A simulation of targeting of the Vim was done using various methods on the 3T images. Furthermore, a correlation with the position of the found target with the 7T SWI was performed. The atlas of Morel et al. (Zurich, CH) was used to confirm the findings on a detailed analysis inside/outside the Gamma Plan. RESULTS: The use of SWI provided us with a superior resolution and an improved image contrast within the basal ganglia. This allowed visualization and direct delineation of some subgroups of thalamic nuclei in vivo, including the Vim. The position of the target, as assessed on 3T, perfectly matched with the supposed one of the Vim on the SWI. Furthermore, a 3-dimensional model of the Vim-target area was created on the basis of the obtained images. CONCLUSION: This is the first report of the integration of SWI high field MRI into the LGP, aiming at the improvement of targeting validation of the Vim in tremor. The anatomical correlation between the direct visualization on 7T and the current targeting methods on 3T (e.g. quadrilatere of Guyot, histological atlases) seems to show a very good anatomical matching. Further studies are needed to validate this technique, both by improving the accuracy of the targeting of the Vim (potentially also other thalamic nuclei) and to perform clinical assessment.

The policy-making structure of European regulatory networks and the domestic adoption of standards

European regulatory networks (ERNs) constitute the main governance instrument for the informal co-ordination of public regulation at the European Union (EU) level. They are in charge of co-ordinating national regulators and ensuring the implementation of harmonized regulatory policies across the EU, while also offering sector-specific expertise to the Commission. To this aim, ERNs develop 'best practices' and benchmarking procedures in the form of standards, norms and guidelines to be adopted in member states. In this paper, we focus on the Committee of European Securities Regulators and examine the consequences of the policy-making structure of ERNs on the domestic adoption of standards. We find that the regulators of countries with larger financial industries tend to occupy more central positions in the network, especially among newer member states. In turn, network centrality is associated with a more prompt domestic adoption of standards.

Global regulation of the knowledge-based economy: The rise of standards in educational services

This article examines the extent and limits of non-state forms of authority in international relations. It analyses how the information and communication technology (ICT) infrastructure for the tradability of services in a global knowledge-based economy relies on informal regulatory practices for adjustment of ICT-related skills. Companies and associations provide training and certification programmes as part of a growing market for educational services setting their own standards. The existing literature on non-conventional forms of authority in the global political economy has emphasised that the consent of actors subject to informal rules and explicit or implicit state recognition remains crucial for the effectiveness of those new forms of power. However, analyses based on a limited sample of actors tend toward a narrow understanding of the issues and fail to fully explore the differentiated space in which non-state authority is emerging. This paper examines the form of authority underpinning the global knowledge-based economy within the broader perspective of the issues likely to be standardised by technical ICT specification, the wide range of actors involved, and the highly differentiated space where standards become authoritative. The empirical findings highlight the role of different private actors in establishing international educational norms in this field. They also pinpoint the limits of profit-oriented standard-settings, notably with regard to generic norms.

Brain network analysis of patients with Temporal Lobe Epilepsy

Patients with Temporal Lobe Epilepsy (TLE) suffer from widespread subtle white matter abnormalities and abnormal functional connectivity extending beyond the affected lobe, as revealed by Diffusion Tensor MR Imaging, volumetric and functional MRI studies. Diffusion Spectrum Imaging (DSI) is a diffusion imaging technique with high angular resolution for improving the mapping of white matter pathways. In this study, we used DSI, connectivity matrices and topological measures to investigate how the alteration in structural connectivity influences whole brain structural networks. Eleven patients with right-sided TLE and hippocampal sclerosis and 18 controls underwent our DSI protocol at 3T. The cortical and subcortical grey matters were parcellated into 86 regions of interest and the connectivity between every region pair was estimated using global tractography and a connectivity matrix (the adjacency matrix of the structural network). We then compared the networks of patients and controls using topological measures. In patients, we found a higher characteristic path length and a lower clustering coefficient compared to controls. Local measures at node level of the clustering and efficiency showed a significant difference after a multiple comparison correction (Bonferroni). These significant nodes were located within as well outside the temporal lobe, and the localisation of most of them was consistent with regions known to be part of epileptic networks in TLE. Our results show altered connectivity patterns that are concordant with the mapping of functional epileptic networks in patients with TLE. Further studies are needed to establish the relevance of these findings for the propagation of epileptic activity, cognitive deficits in medial TLE and outcome of epilepsy surgery in individual patients.

Validación chilena del cuestionario de evaluación de apego en el adulto CAMIR

El objetivo de esta investigación fue examinar la confiabilidad y validez del instrumento de evaluación de apego en el adulto, "Cartes: Modèles Individuels de Relation (CAMIR), en la realidad sociocultural chilena. Este instrumento, basado en la teoría del apego, es un cuestionario de auto-reporte que evalúa los modelos operativos internos en adultos y otras escalas relacionadas al apego. Los participantes fueron 578 sujetos, 204 hombres y 374 mujeres, con edades entre 14 y 80 años. Los sujetos completaron el CAMIR y medidas de vínculo y sintomatología actual, a través del Parental Bonding Instrument (PBI) and Outcome Questionnaire OQ-45.2. A través del análisis estadístico de los resultados se evaluaron las características psicométricas del test y de analiz ó la posibilidad de generar normas locales para la prueba. Los resultados confirmaron que el CAMIR es un instrumento confiable y válido en la evaluación de los modelos internos de relación en adultos. This study was designed to estimate the validity and reliability of the "Cartes: Modèles Individuels de Relation (CAMIR), in Chile. This inventory, based on attachment's theory, it's a auto-questionnaire evaluates the working models in adults and other scales relating to attachment. Participants were 578 individuals, 204 males and 374 females, 14 a 80 years old. Individuals completed the CAMIR and measures of bond and actual symptoms, with the Parental Bonding Instrument (PBI) and Outcome Questionnaire OQ-45.2. The general norms were obtained according to a statistical analysis of the results and to an evaluation of the psychometric characteristics of the test. The results confirmed that the psychometric characteristics of the CAMIR make it a reliable and valid tool to assess working models in adults.

Parental influences on pathogen resistance in brown trout embryos and effects of outcrossing within a river network.

Phenotypic plasticity can increase tolerance to heterogeneous environments but the elevations and slopes of reaction norms are often population specific. Disruption of locally adapted reaction norms through outcrossing can lower individual viability. Here, we sampled five genetically distinct populations of brown trout (Salmo trutta) from within a river network, crossed them in a full-factorial design, and challenged the embryos with the opportunistic pathogen Pseudomonas fluorescens. By virtue of our design, we were able to disentangle effects of genetic crossing distance from sire and dam effects on early life-history traits. While pathogen infection did not increase mortality, it was associated with delayed hatching of smaller larvae with reduced yolk sac reserves. We found no evidence of a relationship between genetic distance (W, FST) and the expression of early-life history traits. Moreover, hybrids did not differ in phenotypic means or reaction norms in comparison to offspring from within-population crosses. Heritable variation in early life-history traits was found to remain stable across the control and pathogen environments. Our findings show that outcrossing within a rather narrow geographical scale can have neutral effects on F1 hybrid viability at the embryonic stage, i.e. at a stage when environmental and genetic effects on phenotypes are usually large.