Representation of motor habit in a sequence of repetitive reach and grasp movements performed by macaque monkeys: evidence for a contribution of the dorsolateral prefrontal cortex.

In the context of an autologous cell transplantation study, a unilateral biopsy of cortical tissue was surgically performed from the right dorsolateral prefrontal cortex (dlPFC) in two intact adult macaque monkeys (dlPFC lesioned group), together with the implantation of a chronic chamber providing access to the left motor cortex. Three other monkeys were subjected to the same chronic chamber implantation, but without dlPFC biopsy (control group). All monkeys were initially trained to perform sequential manual dexterity tasks, requiring precision grip. The motor performance and the prehension's sequence (temporal order to grasp pellets from different spatial locations) were analysed for each hand. Following the surgery, transient and moderate deficits of manual dexterity per se occurred in both groups, indicating that they were not due to the dlPFC lesion (most likely related to the recording chamber implantation and/or general anaesthesia/medication). In contrast, changes of motor habit were observed for the sequential order of grasping in the two monkeys with dlPFC lesion only. The changes were more prominent in the monkey subjected to the largest lesion, supporting the notion of a specific effect of the dlPFC lesion on the motor habit of the monkeys. These observations are reminiscent of previous studies using conditional tasks with delay that have proposed a specialization of the dlPFC for visuo-spatial working memory, except that this is in a different context of "free-will", non-conditional manual dexterity task, without a component of working memory.

Firms in Scottish High Technology Clusters: software, life sciences, microelectronics, optoelectronics and digital media – preliminary evidence and analysis on firm size, growth and optimality

This paper reports on: (a) new primary source evidence on; and (b) statistical and econometric analysis of high technology clusters in Scotland. It focuses on the following sectors: software, life sciences, microelectronics, optoelectronics, and digital media. Evidence on a postal and e-mailed questionnaire is presented and discussed under the headings of: performance, resources, collaboration & cooperation, embeddedness, and innovation. The sampled firms are characterised as being small (viz. micro-firms and SMEs), knowledge intensive (largely graduate staff), research intensive (mean spend on R&D GBP 842k), and internationalised (mainly selling to markets beyond Europe). Preliminary statistical evidence is presented on Gibrat’s Law (independence of growth and size) and the Schumpeterian Hypothesis (scale economies in R&D). Estimates suggest a short-run equilibrium size of just 100 employees, but a long-run equilibrium size of 1000 employees. Further, to achieve the Schumpeterian effect (of marked scale economies in R&D), estimates suggest that firms have to grow to very much larger sizes of beyond 3,000 employees. We argue that the principal way of achieving the latter scale may need to be by takeovers and mergers, rather than by internally driven growth.

Hemispheric competence for auditory spatial representation.

Sound localization relies on the analysis of interaural time and intensity differences, as well as attenuation patterns by the outer ear. We investigated the relative contributions of interaural time and intensity difference cues to sound localization by testing 60 healthy subjects: 25 with focal left and 25 with focal right hemispheric brain damage. Group and single-case behavioural analyses, as well as anatomo-clinical correlations, confirmed that deficits were more frequent and much more severe after right than left hemispheric lesions and for the processing of interaural time than intensity difference cues. For spatial processing based on interaural time difference cues, different error types were evident in the individual data. Deficits in discriminating between neighbouring positions occurred in both hemispaces after focal right hemispheric brain damage, but were restricted to the contralesional hemispace after focal left hemispheric brain damage. Alloacusis (perceptual shifts across the midline) occurred only after focal right hemispheric brain damage and was associated with minor or severe deficits in position discrimination. During spatial processing based on interaural intensity cues, deficits were less severe in the right hemispheric brain damage than left hemispheric brain damage group and no alloacusis occurred. These results, matched to anatomical data, suggest the existence of a binaural sound localization system predominantly based on interaural time difference cues and primarily supported by the right hemisphere. More generally, our data suggest that two distinct mechanisms contribute to: (i) the precise computation of spatial coordinates allowing spatial comparison within the contralateral hemispace for the left hemisphere and the whole space for the right hemisphere; and (ii) the building up of global auditory spatial representations in right temporo-parietal cortices.

Politicians in the Media: Determinants of Legislators' Presence and Prominence in Swiss Newspapers

In times of increasing "mediatization" of politics, when voters and their elected representatives primarily communicate through the media, the question of who gets into the news and why becomes of the utmost importance. This article examines the determinants of Swiss legislators' presence and prominence in the print media by focusing on three competing approaches drawn from communication studies. The first approach regards the media as a "mirror" of political reality and argues that the media focus on the most active deputies in parliament. Second, news values theory predicts that "authoritative" politicians in leadership positions get the most media coverage. Third, theories of "news bias" hold that the media privilege legislators who are in line with their own editorial interests. Overall, the statistical analyses show an important leadership effect and provide strong support for the second explanation. While deputies in official functions get the most extensive news coverage, media access can also be won by parliamentary activity. The least support is shown for the news bias theory, although some newspapers try to localize parliamentary news coverage by focusing on deputies from their own media market.

Creació d'un media center amb software lliure

Treball de recerca realitzat per un alumne d'ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l'any 2009. L’objectiu d’aquest treball de recerca és la creació d’un dispositiu encarregat de centralitzar totes les necessitats multimèdia de casa nostra i distribuir aquest contingut a tots els terminals de la xarxa local d’una manera senzilla i automatitzada. Aquest dispositiu s’ha dissenyat per estar connectat a una televisió d’alta definició, que permetrà la reproducció i l’organització de tot el nostre multimèdia d’una manera còmoda i fàcil. El media center s’encarrega de gestionar la nostra filmoteca, fototeca, biblioteca musical i sèries de TV de manera transparent i automàtica. A més a més, l’usuari pot accedir a tot el multimèdia emmagatzemat al media center des de qualsevol dispositiu de la xarxa local a través de protocols com CIFS o UPnP, en un intent de replicar el cloud computing a escala local. El dispositiu ha estat dissenyat per a suportar tot tipus de formats i subtítols, assegurant la compatibilitat total amb arxius lliures de DRM. El seu disseny minimalista i silenciós el fa perfecte per a substituir el reproductor de DVD de la sala. Tot això sense oblidar el seu baix consum, de l’ordre d’un 75% inferior al d’un PC convencional.

Collective victimisation and collective guilt in the former Yugoslavia : the interplay between individual, local and societal levels

The thesis examines the impact of collective war victimization on individuals' readiness to accept or assign collective guilt for past war atrocities. As a complement to previous studies, its aim is to articulate an integrated approach to collective victimization, which distinguishes between individual-, communal-, and societal-level consequences of warfare. Building on a social representation approach, it is guided by the assumption that individuals form beliefs about a conflict through their personal experiences of victimization, communal experiences of warfare that occur in their proximal surrounding, and the mass- mediatised narratives that circulate in a society's public sphere. Four empirical studies test the hypothesis that individuals' beliefs about the conflict depend on the level and type of war experiences to which they have been exposed, that is, on informative and normative micro and macro contexts in which they are embedded. The studies have been conducted in the context of the Yugoslav wars that attended the breakup of Yugoslavia, a series of wars fought between 1991 and 2001 during which numerous war atrocities were perpetrated causing a massive victimisation of population. To examine the content and impact of war experiences at each level of analysis, the empirical studies employed various methodological strategies, from quantitative analyses of a representative public opinion survey, to qualitative analyses of media content and political speeches. Study 1 examines the impact of individual- and communal- level war experiences on individuals' acceptance and assignment of collective guilt. It further examines the impact of the type of communal level victimization: exposure to symmetric (i.e., violence that similarly affects members of different ethnic groups, including adversaries) and asymmetric violence. The main goal of Study 2 is to examine the structural and political circumstances that enhance collective guilt assignment. While the previous studies emphasize the role of past victimisation, Study 2 tests the assumption that the political demobilisation strategy employed by elites facing public discontent in the collective system-threatening circumstances can fuel out-group blame. Studies 3 and 4 have been conducted predominantly in the context of Croatia and examine rhetoric construction of the dominant politicized narrative of war in a public sphere (Study 3) and its maintenance through public delegitimization of alternative (critical) representations (Study 4). Study 4 further examines the likelihood that highly identified group members adhere to publicly delegitimized critical stances on war. - Cette thèse étudie l'impact de la victimisation collective de guerre sur la capacité des individus à accepter ou à attribuer une culpabilité collective liée à des atrocités commises en temps de guerre. En compléments aux recherches existantes, le but de ce travail est de définir une approche intégrative de la victimisation collective, qui distingue les conséquences de la guerre aux niveaux individuel, régional et sociétal. En partant de l'approche des représentations sociales, cette thèse repose sur le postulat que les individus forment des croyances sur un conflit au travers de leurs expériences personnelles de victimisation, de leurs expériences de guerre lorsque celle-ci se déroule près d'eux, ainsi qu'au travers des récits relayés par les mass media. Quatre études testent l'hypothèse que les croyances des individus dépendent des niveaux et des types d'expériences de guerre auxquels ils ont été exposés, c'est-à-dire, des contextes informatifs et normatifs, micro et macro dans lesquels ils sont insérés. Ces études ont été réalisées dans le contexte des guerres qui, entre 1991 et 2001, ont suivi la dissolution de la Yougoslavie et durant lesquelles de nombreuses atrocités de guerre ont été commises, causant une victimisation massive de la population. Afin d'étudier le contenu et l'impact des expériences de guerre sur chaque niveau d'analyse, différentes stratégies méthodologiques ont été utilisées, des analyses quantitatives sur une enquête représentative d'opinion publique aux analyses qualitatives de contenu de médias et de discours politiques. L'étude 1 étudie l'impact des expériences de guerre individuelles et régionales sur l'acceptation et l'attribution de la culpabilité collective par les individus. Elle examine aussi l'impact du type de victimisation régionale : exposition à la violence symétrique (i.e., violence qui touche les membres de différents groupes ethniques, y compris les adversaires) et asymétrique. L'étude 2 se penche sur les circonstances structurelles et politiques qui augmentent l'attribution de culpabilité collective. Alors que les recherches précédentes ont mis l'accent sur le rôle de la victimisation passée, l'étude 2 teste l'hypothèse que la stratégie de démobilisation politique utilisée par les élites pour faire face à l'insatisfaction publique peut encourager l'attribution de la culpabilité à l'exogroupe. Les études 3 et 4 étudient, principalement dans le contexte croate, la construction rhétorique du récit de guerre politisé dominant (étude 3) et son entretien à travers la délégitimation publique des représentations alternatives (critiques] (étude 4). L'étude 4 examine aussi la probabilité qu'ont les membres de groupe fortement identifiés d'adhérer à des points de vue sur la guerre critiques et publiquement délégitimés.

A numerical solver for a nonlinear Fokker-Planck equation representation of neuronal network dynamics

To describe the collective behavior of large ensembles of neurons in neuronal network, a kinetic theory description was developed in [13, 12], where a macroscopic representation of the network dynamics was directly derived from the microscopic dynamics of individual neurons, which are modeled by conductance-based, linear, integrate-and-fire point neurons. A diffusion approximation then led to a nonlinear Fokker-Planck equation for the probability density function of neuronal membrane potentials and synaptic conductances. In this work, we propose a deterministic numerical scheme for a Fokker-Planck model of an excitatory-only network. Our numerical solver allows us to obtain the time evolution of probability distribution functions, and thus, the evolution of all possible macroscopic quantities that are given by suitable moments of the probability density function. We show that this deterministic scheme is capable of capturing the bistability of stationary states observed in Monte Carlo simulations. Moreover, the transient behavior of the firing rates computed from the Fokker-Planck equation is analyzed in this bistable situation, where a bifurcation scenario, of asynchronous convergence towards stationary states, periodic synchronous solutions or damped oscillatory convergence towards stationary states, can be uncovered by increasing the strength of the excitatory coupling. Finally, the computation of moments of the probability distribution allows us to validate the applicability of a moment closure assumption used in [13] to further simplify the kinetic theory.

Las nuevas tecnologías en la circulación de los discursos literarios y artísticos

La acelerada invención de nuevos hardware y software van modificando, casi diariamente, la percepción del mundo, y, por lo tanto, la producción cultural, permeabilizando conceptos como arte-literatura, cuadro-libro, imagen-texto. Si bien estas parejas han sido siempre objeto del discurso teórico, la discusión asume hoy una urgencia creciente al momento que las nuevas tecnologías exponen lo que estaba refugiado en el reino de la teoría. La misma forma de comprender la realidad se ve afectada por la inmediatez de estos medios. La investigación analiza la obra de diferentes autores de los nuevos medios que trabajan en torno a la problemática de la representación de la memoria en esta perspectiva contemporánea. El trabajo de investigación desarrollado en la Tesis Doctoral se centra en la forma de representación de la memoria, así como esta planteada en la obra de Chris Marker. Interesan especialmente los últimos dispositivos creados por el autor en el marco de las llamadas nuevas tecnologías y los nuevos espacios de exposición de cine. El proyecto propone un análisis en torno a la memoria que dichos discursos sugieren a través de los temas que les son propios: archivo, identidades culturales, contribución del espectador, base de datos y tratamiento tecnológico de la información. Se ha seleccionado la obra de Chris Marker por las características de realización y de discurso que permiten una amplia discusión sobre las llamadas nuevas tecnologías y el mundo que éstas representan en el nuevo espacio híbrido construido entre las artes visuales, la literatura y la tecnología.

Semi-supervised segmentation of ultrasound images based on patch representation and continuous min cut.

Ultrasound segmentation is a challenging problem due to the inherent speckle and some artifacts like shadows, attenuation and signal dropout. Existing methods need to include strong priors like shape priors or analytical intensity models to succeed in the segmentation. However, such priors tend to limit these methods to a specific target or imaging settings, and they are not always applicable to pathological cases. This work introduces a semi-supervised segmentation framework for ultrasound imaging that alleviates the limitation of fully automatic segmentation, that is, it is applicable to any kind of target and imaging settings. Our methodology uses a graph of image patches to represent the ultrasound image and user-assisted initialization with labels, which acts as soft priors. The segmentation problem is formulated as a continuous minimum cut problem and solved with an efficient optimization algorithm. We validate our segmentation framework on clinical ultrasound imaging (prostate, fetus, and tumors of the liver and eye). We obtain high similarity agreement with the ground truth provided by medical expert delineations in all applications (94% DICE values in average) and the proposed algorithm performs favorably with the literature.

Application of a roughness-length representation to parameterize energy loss in 3-D numerical simulations of large rivers

Recent technological advances in remote sensing have enabled investigation of the morphodynamics and hydrodynamics of large rivers. However, measuring topography and flow in these very large rivers is time consuming and thus often constrains the spatial resolution and reach-length scales that can be monitored. Similar constraints exist for computational fluid dynamics (CFD) studies of large rivers, requiring maximization of mesh-or grid-cell dimensions and implying a reduction in the representation of bedform-roughness elements that are of the order of a model grid cell or less, even if they are represented in available topographic data. These ``subgrid'' elements must be parameterized, and this paper applies and considers the impact of roughness-length treatments that include the effect of bed roughness due to ``unmeasured'' topography. CFD predictions were found to be sensitive to the roughness-length specification. Model optimization was based on acoustic Doppler current profiler measurements and estimates of the water surface slope for a variety of roughness lengths. This proved difficult as the metrics used to assess optimal model performance diverged due to the effects of large bedforms that are not well parameterized in roughness-length treatments. However, the general spatial flow patterns are effectively predicted by the model. Changes in roughness length were shown to have a major impact upon flow routing at the channel scale. The results also indicate an absence of secondary flow circulation cells in the reached studied, and suggest simpler two-dimensional models may have great utility in the investigation of flow within large rivers. Citation: Sandbach, S. D. et al. (2012), Application of a roughness-length representation to parameterize energy loss in 3-D numerical simulations of large rivers, Water Resour. Res., 48, W12501, doi: 10.1029/2011WR011284.

The Media and Socio-Cultural Regulation of Religion

(Résumé de l'ouvrage) Originale, insolite, renaissante, l'action religieuse émergente bouscule les habitudes, ébranle les certitudes, construit ici, maintenant, l'autre monde. Peut-on courir le risque? Voilà que la question se pose et se résout en rumeurs publiques, poursuites judiciaires et tensions scolaires, lesquelles mettent à nu des mécanismes inédits d'institutionnalisation de l'expérience religieuse en modernité. As new religious movements seek to carve out their own niche in society, public controversy and opposing beliefs can spark bitter debates, and can even lead to calls for state intervention. How then do new or borderline religious groups negotiate or mediate the building of public space?

Delayed otogenic hydrocephalus after acute otitis media in pediatric patients: the changing presentation of a serious otologic complication.

CONCLUSIONS: The clinical presentation of otogenic dural sinus thrombosis (DST) as a complication of acute otitis media (AOM) can be masked by antibiotic treatment. Morning episodes of vomiting and/or headache, visual impairment and a history of AOM seem to be indicative of otogenic hydrocephalus. We therefore advocate that the MRI scans of patients with similar symptoms should be carefully studied to facilitate the early diagnosis of a potentially life-threatening complication. OBJECTIVE: To describe the frequency, pathognomonic signs, clinical course and outcome of otogenic hydrocephalus and DST as complications of AOM in pediatric patients. MATERIAL AND METHODS: We undertook a retrospective chart review of all pediatric patients (age 1-14 years) treated for otitis media and its complications at an academic medical center between 1999 and 2003. The main outcome measures were otologic and ophthalmologic findings and CT and MRI scans at the beginning of treatment and 3 months later. RESULTS: We report on five cases with otogenic DST following AOM. All but one of them presented initially with diplopia caused by otogenic hydrocephalus. In four cases the otologic complaints had already disappeared by the time of MRI confirmation of the diagnosis. Only one child was referred with severe otologic symptoms. Management included systemic antibiotics, short-term heparin anticoagulation and surgical decompression. In our cases, even after intensive i.v. antibiotic treatment, only surgery led to a significant improvement in the clinical condition.