47 resultados para embodied skill
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Recent findings in neuroscience suggest that adult brain structure changes in response to environmental alterations and skill learning. Whereas much is known about structural changes after intensive practice for several months, little is known about the effects of single practice sessions on macroscopic brain structure and about progressive (dynamic) morphological alterations relative to improved task proficiency during learning for several weeks. Using T1-weighted and diffusion tensor imaging in humans, we demonstrate significant gray matter volume increases in frontal and parietal brain areas following only two sessions of practice in a complex whole-body balancing task. Gray matter volume increase in the prefrontal cortex correlated positively with subject's performance improvements during a 6 week learning period. Furthermore, we found that microstructural changes of fractional anisotropy in corresponding white matter regions followed the same temporal dynamic in relation to task performance. The results make clear how marginal alterations in our ever changing environment affect adult brain structure and elucidate the interrelated reorganization in cortical areas and associated fiber connections in correlation with improvements in task performance.
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RESUME« L'insertion sociale plurielle des femmes cadres supérieurs en Suisse. Contribution à l'étude du bien-être subjectif au quotidien. Approche intégrative qualitative. »Depuis une quarantaine d'années, nombreux sont les travaux qui étudient les relations entre les différents milieux de vie au quotidien et, plus particulièrement, l'impact de leurs articulations singulières sur la santé. Nous y identifions deux axes principaux : l'un aborde ce phénomène selon une perspective de « conflit travail-famille » en termes de « stress », l'autre se focalise davantage sur la promotion du « bien-être » au travers d'une approche d'« équilibre travail-vie ». Or, l'ensemble de ces recherches considère comme «pathogènes» les désajustements, les contradictions et les tensions vécus au quotidien. Selon cette tendance, le « bien-être » apparaît comme un état d'équilibre ultime indépendant du contexte de vie du sujet. Toutefois, peu de recherches portent sur la dimension située du bien-être dans son rapport à l'activité concrète au sein des milieux deNotre étude s'intéresse à cette question auprès des femmes cadres supérieurs, selon une perspective critique et développementale en psychologie de la santé (Lyons & Chamberlain, 2006 ; Santiago-Delefosse, 2002,2011 ; Malrieu, 1989 ; Vygotski, 1985). En effet, cette population constitue un terrain privilégié pour comprendre le sens donné à l'activité à partir des contraintes, responsabilités et demandes perçues dans des contextes parfois contradictoires, et pour analyser le rôle de ces derniers dans un bien-être subjectif.En cohérence avec notre positionnement théorique, nous avons mené des entretiens qualitatifs focalisés sur l'activité quotidienne auprès de 20 femmes, et ceci en deux temps (T1-T2) (40 entretiens). Les résultats issus des analyses du contenu des discours permettent de définir le vécu de l'articulation des milieux de vie chez nos participantes, selon trois axes à la fois interdépendants et autonomes. Chaque axe se définit par une série de supports spécifiques jouant un rôle structurant dans leur bien-être subjectif. Ainsi, le premier axe se caractérise par des supports de maîtrise subjective, ainsi que par l'appropriation de contraintes sociales et corporelles, selon un rythme de l'activité soutenu. Le deuxième s'accompagne de supports qui favorisent la prise de distance au travers du relâchement du rythme et du lâcher prise de la maîtrise, par la création d'espaces personnels et sociaux « pour soi ». Enfin, le troisième porte sur le positionnement de soi par rapport à autrui en termes de « personnalisation ».Construits en rapport à la corporéité et à autrui au sein de contextes spécifiques, ces différents supports prennent leur sens au sein d'un système de pratiques global, unique pour chaque femme. Selon cette conception critique, le bien-être subjectif chez les femmes cadres se définit comme le fruit d'un processus mouvant issu des tensions vécues entre les trois axes de l'articulation des milieux de vie. Il est par conséquent social, corporel et psychologique.Nos résultats ouvrent des perspectives de recherche et d'intervention, notamment en santé et travail. Ces ouvertures sont orientées vers une approche intégrative en psychologie de la santé, c'est-à-dire, de la prise en compte dans des questions de santé et de bien-être du processus de construction du sujet en relation à son insertion sociale plurielle.ABSTRACT« Plural social participation among women senior managers in Switzerland. Contribution to the study of subjective well-being in everyday life. An integrative and qualitativeapproach.»For the last forty years, a large body of literature has studied the relationships between different social realms in everyday life and, more particularly, the impact of their singular intertwinements with health. We identify two main trends : The first one focuses on this phenomenon through the « work-family conflict » perspective in terms of « stress » whilst the second one is more concerned by the promotion of « well-being » through a « work-life balance » approach. However, both of these trends consider disadjustments, contradictions and tensions in everyday life as « pathogenic ». According to this conception, « well- being » appears as an ultimate state of balance which is indépendant from the subject's life context. Nevertheless, few studies have examined the situated dimension of well-being in its link to concrete activity in social realms.Our research is concerned with this issue among women senior managers from a critical and developmental perspective in Health Psychology (Lyons & Chamberlain, 2006 ; Santiago-Delefosse, 2002, 2011 ; Malrieu, 1989 ; Vygotski, 1985). In fact, this population represents a favourable field so as to study : how the meaning of daily activity is constructed accross different and often conflictive social realms ; to understand the many ways in which this population deals with perceived constraints, responsibilities and requests, and to analyse the role of situated plural activity in subjective well-being.Consitent with our theoretical framework, we have designed a qualitative method. We have conducted two-time (T1-T2) interviews with 20 women by focusing on their daily activity (40 interviews). The Thematic Content Analysis reveals that four different social realms are articulated among our participants through three main axes, which are at the same time interdependent and autonomous. Each one of these axis is defined by a certain number of specific supports that play an important role in these women's subjective well- being. The first axis is concerned by several supports that signify a « feeling of control » along with the appropriation of social and body constraints by means of a rapid pace of activity. The second one regards the use of supports that contribute to « put things into perspective » by means of the slowing down of the pace of activity and through letting go of the feeling of control. This mechanism includes the creation of personal and social spaces of « one's own ». The third axis is defined by the positioning of the self in regard to others through a process of « personnalization ».Developed in specific contexts through the intertwinnements between the body and social others, supports belonging to these axes acquire significance and meaning on the basis of their relationship to a global system of activities of which they are part. However, this articulation is uniquely defined for each participant. According to this critical approach, subjective well-being among women senior managers emerges as a meaningful and changing process, situated in a plural social context. This is, it appears as the result of conflictual interactions defining the three different axis that we have identified. Subjective well-being is hence a social, embodied and psychological phenomena that is closely linked to the articulation of different social realms. Our findings open new research and practice perspectives, especially concerning health and work issues. These perspectives convey an integrative approach in Health Psychology by considering health and well-being by taking into account the process of construction of the subject in regard to his or her plural social participation.
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This paper deals with the recruitment strategies of employers in the low-skilled segment of the labour market. We focus on low-skilled workers because they are overrepresented among jobless people and constitute the bulk of the clientele included in various activation and labour market programmes. A better understanding of the constraints and opportunities of interventions in this labour market segment may help improve their quality and effectiveness. On the basis of qualitative interviews with 41 employers in six European countries, we find that the traditional signals known to be used as statistical discrimination devices (old age, immigrant status and unemployment) play a somewhat reduced role, since these profiles are overrepresented among applicants for low skill positions. However, we find that other signals, mostly considered to be indicators of motivation, have a bigger impact in the selection process. These tend to concern the channel through which the contact with a prospective candidate is made. Unsolicited applications and recommendations from already employed workers emit a positive signal, whereas the fact of being referred by the public employment office is associated with the likelihood of lower motivation.
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The Organization of the Thesis The remainder of the thesis comprises five chapters and a conclusion. The next chapter formalizes the envisioned theory into a tractable model. Section 2.2 presents a formal description of the model economy: the individual heterogeneity, the individual objective, the UI setting, the population dynamics and the equilibrium. The welfare and efficiency criteria for qualifying various equilibrium outcomes are proposed in section 2.3. The fourth section shows how the model-generated information can be computed. Chapter 3 transposes the model from chapter 2 in conditions that enable its use in the analysis of individual labor market strategies and their implications for the labor market equilibrium. In section 3.2 the Swiss labor market data sets, stylized facts, and the UI system are presented. The third section outlines and motivates the parameterization method. In section 3.4 the model's replication ability is evaluated and some aspects of the parameter choice are discussed. Numerical solution issues can be found in the appendix. Chapter 4 examines the determinants of search-strategic behavior in the model economy and its implications for the labor market aggregates. In section 4.2, the unemployment duration distribution is examined and related to search strategies. Section 4.3 shows how the search- strategic behavior is influenced by the UI eligibility and section 4.4 how it is determined by individual heterogeneity. The composition effects generated by search strategies in labor market aggregates are examined in section 4.5. The last section evaluates the model's replication of empirical unemployment escape frequencies reported in Sheldon [67]. Chapter 5 applies the model economy to examine the effects on the labor market equilibrium of shocks to the labor market risk structure, to the deep underlying labor market structure and to the UI setting. Section 5.2 examines the effects of the labor market risk structure on the labor market equilibrium and the labor market strategic behavior. The effects of alterations in the labor market deep economic structural parameters, i.e. individual preferences and production technology, are shown in Section 5.3. Finally, the UI setting impacts on the labor market are studied in Section 5.4. This section also evaluates the role of the UI authority monitoring and the differences in the Way changes in the replacement rate and the UI benefit duration affect the labor market. In chapter 6 the model economy is applied in counterfactual experiments to assess several aspects of the Swiss labor market movements in the nineties. Section 6.2 examines the two equilibria characterizing the Swiss labor market in the nineties, the " growth" equilibrium with a "moderate" UI regime and the "recession" equilibrium with a more "generous" UI. Section 6.3 evaluates the isolated effects of the structural shocks, while the isolated effects of the UI reforms are analyzed in section 6.4. Particular dimensions of the UI reforms, the duration, replacement rate and the tax rate effects, are studied in section 6.5, while labor market equilibria without benefits are evaluated in section 6.6. In section 6.7 the structural and institutional interactions that may act as unemployment amplifiers are discussed in view of the obtained results. A welfare analysis based on individual welfare in different structural and UI settings is presented in the eighth section. Finally, the results are related to more favorable unemployment trends after 1997. The conclusion evaluates the features embodied in the model economy with respect to the resulting model dynamics to derive lessons from the model design." The thesis ends by proposing guidelines for future improvements of the model and directions for further research.
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OBJECTIVE: To assess the effect of a governmentally-led center based child care physical activity program (Youp'la Bouge) on child motor skills.Patients and methods: We conducted a single blinded cluster randomized controlled trial in 58 Swiss child care centers. Centers were randomly selected and 1:1 assigned to a control or intervention group. The intervention lasted from September 2009 to June 2010 and included training of the educators, adaptation of the child care built environment, parental involvement and daily physical activity. Motor skill was the primary outcome and body mass index (BMI), physical activity and quality of life secondary outcomes. The intervention implementation was also assessed. RESULTS: At baseline, 648 children present on the motor test day were included (age 3.3 +/- 0.6, BMI 16.3 +/- 1.3 kg/m2, 13.2% overweight, 49% girls) and 313 received the intervention. Relative to children in the control group (n = 201), children in the intervention group (n = 187) showed no significant increase in motor skills (delta of mean change (95% confidence interval: -0.2 (-0.8 to 0.3), p = 0.43) or in any of the secondary outcomes. Not all child care centers implemented all the intervention components. Within the intervention group, several predictors were positively associated with trial outcomes: 1) free-access to a movement space and parental information session for motor skills 2) highly motivated and trained educators for BMI 3) free-access to a movement space and purchase of mobile equipment for physical activity (all p < 0.05). CONCLUSION: This "real-life" physical activity program in child care centers confirms the complexity of implementing an intervention outside a study setting and identified potentially relevant predictors that could improve future programs.Trial registration: Trial registration number: clinical trials.gov NCT00967460 http://clinicaltrials.gov/ct2/show/NCT00967460.
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Does a conflict between inborn motor preferences and educational standards during childhood impact the structure of the adult human brain? To examine this issue, we acquired high-resolution T1-weighted magnetic resonance scans of the whole brain in adult "converted" left-handers who had been forced as children to become dextral writers. Analysis of sulcal surfaces revealed that consistent right- and left-handers showed an interhemispheric asymmetry in the surface area of the central sulcus with a greater surface contralateral to the dominant hand. This pattern was reversed in the converted group who showed a larger surface of the central sulcus in their left, nondominant hemisphere, indicating plasticity of the primary sensorimotor cortex caused by forced use of the nondominant hand. Voxel-based morphometry showed a reduction of gray matter volume in the middle part of the left putamen in converted left-handers relative to both consistently handed groups. A similar trend was found in the right putamen. Converted subjects with at least one left-handed first-degree relative showed a correlation between the acquired right-hand advantage for writing and the structural changes in putamen and pericentral cortex. Our results show that a specific environmental challenge during childhood can shape the macroscopic structure of the human basal ganglia. The smaller than normal putaminal volume differs markedly from previously reported enlargement of cortical gray matter associated with skill acquisition. This indicates a differential response of the basal ganglia to early environmental challenges, possibly related to processes of pruning during motor development.
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RÉSUMÉ Cette thèse porte sur le développement de méthodes algorithmiques pour découvrir automatiquement la structure morphologique des mots d'un corpus. On considère en particulier le cas des langues s'approchant du type introflexionnel, comme l'arabe ou l'hébreu. La tradition linguistique décrit la morphologie de ces langues en termes d'unités discontinues : les racines consonantiques et les schèmes vocaliques. Ce genre de structure constitue un défi pour les systèmes actuels d'apprentissage automatique, qui opèrent généralement avec des unités continues. La stratégie adoptée ici consiste à traiter le problème comme une séquence de deux sous-problèmes. Le premier est d'ordre phonologique : il s'agit de diviser les symboles (phonèmes, lettres) du corpus en deux groupes correspondant autant que possible aux consonnes et voyelles phonétiques. Le second est de nature morphologique et repose sur les résultats du premier : il s'agit d'établir l'inventaire des racines et schèmes du corpus et de déterminer leurs règles de combinaison. On examine la portée et les limites d'une approche basée sur deux hypothèses : (i) la distinction entre consonnes et voyelles peut être inférée sur la base de leur tendance à alterner dans la chaîne parlée; (ii) les racines et les schèmes peuvent être identifiés respectivement aux séquences de consonnes et voyelles découvertes précédemment. L'algorithme proposé utilise une méthode purement distributionnelle pour partitionner les symboles du corpus. Puis il applique des principes analogiques pour identifier un ensemble de candidats sérieux au titre de racine ou de schème, et pour élargir progressivement cet ensemble. Cette extension est soumise à une procédure d'évaluation basée sur le principe de la longueur de description minimale, dans- l'esprit de LINGUISTICA (Goldsmith, 2001). L'algorithme est implémenté sous la forme d'un programme informatique nommé ARABICA, et évalué sur un corpus de noms arabes, du point de vue de sa capacité à décrire le système du pluriel. Cette étude montre que des structures linguistiques complexes peuvent être découvertes en ne faisant qu'un minimum d'hypothèses a priori sur les phénomènes considérés. Elle illustre la synergie possible entre des mécanismes d'apprentissage portant sur des niveaux de description linguistique distincts, et cherche à déterminer quand et pourquoi cette coopération échoue. Elle conclut que la tension entre l'universalité de la distinction consonnes-voyelles et la spécificité de la structuration racine-schème est cruciale pour expliquer les forces et les faiblesses d'une telle approche. ABSTRACT This dissertation is concerned with the development of algorithmic methods for the unsupervised learning of natural language morphology, using a symbolically transcribed wordlist. It focuses on the case of languages approaching the introflectional type, such as Arabic or Hebrew. The morphology of such languages is traditionally described in terms of discontinuous units: consonantal roots and vocalic patterns. Inferring this kind of structure is a challenging task for current unsupervised learning systems, which generally operate with continuous units. In this study, the problem of learning root-and-pattern morphology is divided into a phonological and a morphological subproblem. The phonological component of the analysis seeks to partition the symbols of a corpus (phonemes, letters) into two subsets that correspond well with the phonetic definition of consonants and vowels; building around this result, the morphological component attempts to establish the list of roots and patterns in the corpus, and to infer the rules that govern their combinations. We assess the extent to which this can be done on the basis of two hypotheses: (i) the distinction between consonants and vowels can be learned by observing their tendency to alternate in speech; (ii) roots and patterns can be identified as sequences of the previously discovered consonants and vowels respectively. The proposed algorithm uses a purely distributional method for partitioning symbols. Then it applies analogical principles to identify a preliminary set of reliable roots and patterns, and gradually enlarge it. This extension process is guided by an evaluation procedure based on the minimum description length principle, in line with the approach to morphological learning embodied in LINGUISTICA (Goldsmith, 2001). The algorithm is implemented as a computer program named ARABICA; it is evaluated with regard to its ability to account for the system of plural formation in a corpus of Arabic nouns. This thesis shows that complex linguistic structures can be discovered without recourse to a rich set of a priori hypotheses about the phenomena under consideration. It illustrates the possible synergy between learning mechanisms operating at distinct levels of linguistic description, and attempts to determine where and why such a cooperation fails. It concludes that the tension between the universality of the consonant-vowel distinction and the specificity of root-and-pattern structure is crucial for understanding the advantages and weaknesses of this approach.
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Background: Patient change talk (CT) during brief motivational interventions (BMI) has been linked with subsequent changes in drinking in clinical settings but this link has not been clearly established among young people in non-clinical populations. Objective: To determine which of several CT dimensions assessed during an effective BMI delivered in a non-clinical setting to 20-year old men are associated with drinking 6 months later. Methods: Of 125 individuals receiving a face-to-face BMI session (15.8 ± 5.4 minutes), we recorded and coded a subsample of 42 sessions using the Motivational Interviewing Skill Code 2.1. Each patient change talk utterance was categorized as `Reason´, `Ability´, `Desire´, `Need´, `Commitment´, `Taking steps´, or `Other´. Each utterance was graded according to its strength (absolute value from 1 to 3) and direction (i.e. towards (positive sign) or away (negative sign) from change/in favor of status quo). `Ability´, `Desire´, and `Need´ to change (`ADN´) were grouped together since these codes were too scarce to conduct analyses. Mean strength scores over the entire session were computed for each dimension and later dichotomized in towards change (i.e. mean core > 0) and away from change/in favor of status quo. Negative binomial regression models were used to assess the relationship between CT dimensions and drinking 6 months later, adjusting for drinking at baseline. Results: Compared to subjects with a `Taking steps´ score away from change/in favor of status quo, subjects with a positive `Taking steps´ score reported significantly less drinking 6 months later (Incidence Rate Ration [IRR] for drinks per week: 0.56, 95% Confidence Interval [CI] 0.31, 1.00). IRR (95%CI) for subjects with a positive `ADN´ score was 0.58, (0.32, 1.03). For subjects with a positive `Reason´, `Commitment´, and `Other´ scores, IRR (95%CI) were 1.28 (0.77; 2.12) 1.63 (0.85; 3.14) and 1.03 (0.61; 1.72), respectively. Conclusion: A change talk dimension reflecting steps taken towards change (`Taking steps´) is associated with less drinking 6 months later among young men receiving a BMI in a non-clinical setting. Encouraging patients to take steps towa change may be a worthy objective for clinicians and may explain BMI efficacy.
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Client change talk (CT) during motivational interviewing and brief motivational interventions (BMIs) have been described as predictors of behavior change, but these links have not been clearly evaluated in research on young people. Within 127 BMIs with 20-year-old men with at-risk alcohol consumption, each CT utterance was categorized and given a strength rating using the Motivational Interviewing Skill Code 2.1. Several ways of categorizing and measuring CT were tested using stepwise regression procedures. Overall CT measures were not significantly related to changes in drinking at 6-month follow-up. Regarding CT sub-dimensions, the frequency of ability/desire/need to change and of ability/desire/need not to change, as well as the average strength of ability/desire/need, predicted significant change in the expected direction. CT length was not significantly linked to outcome. The frequency and strength with which some CT sub-dimensions are expressed during BMI seemed to be important predictors of change in drinking among young men and might thus be especially important for clinicians to notice.
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La paracentèse abdominale est un geste fréquemment réalisé en pratique clinique. Il est indispensable de procéder à ce geste dans un but diagnostique en cas d'ascite nouvellement mise en évidence. Chez un patient connu pour une ascite, chaque détérioration clinique ou des paramètres biologiques nécessite une nouvelle paracentèse. Ce geste peut être également réalisé dans un but thérapeutique en cas d'ascite réfractaire, d'inconfort abdominal ou de dyspnée. Comme pour toute procédure invasive, il convient d'en connaître les indications et contre-indications, le matériel nécessaire ainsi que les complications et leur traitement. Abdominal paracentesis is frequently performed in the clinical setting. Every newly developed ascites need to be investigated by abdominal paracentesis. Any clinical or biological deterioration in patients with chronic ascites also requires a new paracentesis. Therapeutically abdominal paracentesis is performed for refractory or symptomatic ascites. As other invasive procedures, it is critical to master its indications, contra-indications and complications. The aim of this article is to review the basics of abdominal paracentesis in order to help physicians to carry out this technical skill
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At the beginning of the 1990s, the concept of "European integration" could still be said to be fairly unambiguous. Nowadays, it has become plural and complex almost to the point of unintelligibility. This is due, of course, to the internal differentiation of EU membership, with several Member States pulling out of key integrative projects such as establishing an area without frontiers, the "Schengen" area, and a common currency. But this is also due to the differentiated extension of key integrative projects to European non-EU countries - Schengen is again a case in point. Such processes of "integration without membership", the focus of the present publication, are acquiring an ever-growing topicality both in the political arena and in academia. International relations between the EU and its neighbouring countries are crucial for both, and their development through new agreements features prominently on the continent's political agenda. Over and above this aspect, the dissemination of EU values and standards beyond the Union's borders raises a whole host of theoretical and methodological questions, unsettling in some cases traditional conceptions of the autonomy and separation of national legal orders. This publication brings together the papers presented at the Integration without EU Membership workshop held in May 2008 at the EUI (Max Weber Programme and Department of Law). It aims to compare different models and experiences of integration between the EU, on the one hand, and those European countries that do not currently have an accession perspective on the other hand. In delimiting the geographical scope of the inquiry, so as to scale it down to manageable proportions, the guiding principles have been to include both the "Eastern" and "Western" neighbours of the EU, and to examine both structured frameworks of cooperation, such as the European Neighbourhood Policy and the European Economic Area, and bilateral relations developing on a more ad hoc basis. These principles are reflected in the arrangement of the papers, which consider in turn the positions of Ukraine, Russia, Norway, and Switzerland in European integration - current standing, perspectives for evolution, consequences in terms of the EU-ization of their respective legal orders1. These subjects are examined from several perspectives. We had the privilege of receiving contributions from leading practitioners and scholars from the countries concerned, from EU highranking officials, from prominent specialists in EU external relations law, and from young and talented researchers. We wish to thank them all here for their invaluable insights. We are moreover deeply indebted to Marise Cremona (EUI, Law Department, EUI) for her inspiring advice and encouragement, as well as to Ramon Marimon, Karin Tilmans, Lotte Holm, Alyson Price and Susan Garvin (Max Weber Programme, EUI) for their unflinching support throughout this project. A word is perhaps needed on the propriety and usefulness of the research concept embodied in this publication. Does it make sense to compare the integration models and experiences of countries as different as Norway, Russia, Switzerland, and Ukraine? Needless to say, this list of four evokes a staggering diversity of political, social, cultural, and economic conditions, and at least as great a diversity of approaches to European integration. Still, we would argue that such diversity only makes comparisons more meaningful. Indeed, while the particularities and idiosyncratic elements of each "model" of integration are fully displayed in the present volume, common themes and preoccupations run through the pages of every contribution: the difficulty in conceptualizing the finalité and essence of integration, which is evident in the EU today but which is greatly amplified for non-EU countries; the asymmetries and tradeoffs between integration and autonomy that are inherent in any attempt to participate in European integration from outside; the alteration of deeply seated legal concepts, and concepts about the law, that are already observable in the most integrated of the non-EU countries concerned. These issues are not transient or coincidental: they are inextricably bound up with the integration of non-EU countries in the EU project. By publishing this collection, we make no claim to have dealt with them in an exhaustive, still less in a definitive manner. Our ambition is more modest: to highlight the relevance of these themes, to place them more firmly on the scientific agenda, and to provide a stimulating basis for future research and reflection.
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OBJECTIVE: : Plunging when drilling can be a detrimental factor in patient care. There is, although, a general lack of information regarding the surgeon's performance in this skill. The aim of this study was to determine the effect that using sharp or blunt instruments had on the drill bit's soft tissue penetration, using a simulator. MATERIALS AND METHODS: : Surgeons taking part in an International Trauma Course were invited to participate. Two groups were defined: experienced and inexperienced surgeons. Twelve holes were drilled in the following order: 3 holes with a sharp drill bit in normal bone (SNB), 3 holes with a sharp drill bit in osteoporotic bone (SOB), 3 holes with a blunt drill bit in normal bone, and 3 holes with a blunt drill bit in osteoporotic bone. Mean values and Student t tests were used for statistical analysis. RESULTS: : Thirty-seven surgeons participated, 20 experienced and 17 inexperienced surgeons. Mean plunging depths for SNB, SOB, blunt drill bit in normal bone, and blunt drill bit in osteoporotic bone were, respectively, 5.1, 5.4, 21.1, and 13.9 mm for experienced surgeons and 7.6, 7.7, 22, and 15.9 mm for inexperienced surgeons. Drilling with SNB and with SOB was statistically different, with inexperienced surgeons plunging 2.5 mm (P = 0.31) and 2.6 mm (P = 0.042) deeper, respectively. There was a difference (P < 0.001) between sharp and blunt drill bits in all drilling conditions for both the groups. CONCLUSIONS: : Our study showed a significant difference in plunging depth when sharp or bunt drill bit was being used. Surgeons, regardless of their experience level, penetrate over 20 mm in normal bone and over 10 mm in osteoporotic bone.
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It has been convincingly argued that computer simulation modeling differs from traditional science. If we understand simulation modeling as a new way of doing science, the manner in which scientists learn about the world through models must also be considered differently. This article examines how researchers learn about environmental processes through computer simulation modeling. Suggesting a conceptual framework anchored in a performative philosophical approach, we examine two modeling projects undertaken by research teams in England, both aiming to inform flood risk management. One of the modeling teams operated in the research wing of a consultancy firm, the other were university scientists taking part in an interdisciplinary project experimenting with public engagement. We found that in the first context the use of standardized software was critical to the process of improvisation, the obstacles emerging in the process concerned data and were resolved through exploiting affordances for generating, organizing, and combining scientific information in new ways. In the second context, an environmental competency group, obstacles were related to the computer program and affordances emerged in the combination of experience-based knowledge with the scientists' skill enabling a reconfiguration of the mathematical structure of the model, allowing the group to learn about local flooding.
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Ignoring irrelevant visual information aids efficient interaction with task environments. We studied how people, after practice, start to ignore the irrelevant aspects of stimuli. For this we focused on how information reduction transfers to rarely practised and novel stimuli. In Experiment 1, we compared competing mathematical models on how people cease to fixate on irrelevant parts of stimuli. Information reduction occurred at the same rate for frequent, infrequent, and novel stimuli. Once acquired with some stimuli, it was applied to all. In Experiment 2, simplification of task processing also occurred in a once-for-all manner when spatial regularities were ruled out so that people could not rely on learning which screen position is irrelevant. Apparently, changes in eye movements were an effect of a once-for-all strategy change rather than a cause of it. Overall, the results suggest that participants incidentally acquired knowledge about regularities in the task material and then decided to voluntarily apply it for efficient task processing. Such decisions should be incorporated into accounts of information reduction and other theories of strategy change in skill acquisition.
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This thesis is composed of three main parts. The first consists of a state of the art of the different notions that are significant to understand the elements surrounding art authentication in general, and of signatures in particular, and that the author deemed them necessary to fully grasp the microcosm that makes up this particular market. Individuals with a solid knowledge of the art and expertise area, and that are particularly interested in the present study are advised to advance directly to the fourth Chapter. The expertise of the signature, it's reliability, and the factors impacting the expert's conclusions are brought forward. The final aim of the state of the art is to offer a general list of recommendations based on an exhaustive review of the current literature and given in light of all of the exposed issues. These guidelines are specifically formulated for the expertise of signatures on paintings, but can also be applied to wider themes in the area of signature examination. The second part of this thesis covers the experimental stages of the research. It consists of the method developed to authenticate painted signatures on works of art. This method is articulated around several main objectives: defining measurable features on painted signatures and defining their relevance in order to establish the separation capacities between groups of authentic and simulated signatures. For the first time, numerical analyses of painted signatures have been obtained and are used to attribute their authorship to given artists. An in-depth discussion of the developed method constitutes the third and final part of this study. It evaluates the opportunities and constraints when applied by signature and handwriting experts in forensic science. A brief summary covering each chapter allows a rapid overview of the study and summarizes the aims and main themes of each chapter. These outlines presented below summarize the aims and main themes addressed in each chapter. Part I - Theory Chapter 1 exposes legal aspects surrounding the authentication of works of art by art experts. The definition of what is legally authentic, the quality and types of the experts that can express an opinion concerning the authorship of a specific painting, and standard deontological rules are addressed. The practices applied in Switzerland will be specifically dealt with. Chapter 2 presents an overview of the different scientific analyses that can be carried out on paintings (from the canvas to the top coat). Scientific examinations of works of art have become more common, as more and more museums equip themselves with laboratories, thus an understanding of their role in the art authentication process is vital. The added value that a signature expertise can have in comparison to other scientific techniques is also addressed. Chapter 3 provides a historical overview of the signature on paintings throughout the ages, in order to offer the reader an understanding of the origin of the signature on works of art and its evolution through time. An explanation is given on the transitions that the signature went through from the 15th century on and how it progressively took on its widely known modern form. Both this chapter and chapter 2 are presented to show the reader the rich sources of information that can be provided to describe a painting, and how the signature is one of these sources. Chapter 4 focuses on the different hypotheses the FHE must keep in mind when examining a painted signature, since a number of scenarios can be encountered when dealing with signatures on works of art. The different forms of signatures, as well as the variables that may have an influence on the painted signatures, are also presented. Finally, the current state of knowledge of the examination procedure of signatures in forensic science in general, and in particular for painted signatures, is exposed. The state of the art of the assessment of the authorship of signatures on paintings is established and discussed in light of the theoretical facets mentioned previously. Chapter 5 considers key elements that can have an impact on the FHE during his or her2 examinations. This includes a discussion on elements such as the skill, confidence and competence of an expert, as well as the potential bias effects he might encounter. A better understanding of elements surrounding handwriting examinations, to, in turn, better communicate results and conclusions to an audience, is also undertaken. Chapter 6 reviews the judicial acceptance of signature analysis in Courts and closes the state of the art section of this thesis. This chapter brings forward the current issues pertaining to the appreciation of this expertise by the non- forensic community, and will discuss the increasing number of claims of the unscientific nature of signature authentication. The necessity to aim for more scientific, comprehensive and transparent authentication methods will be discussed. The theoretical part of this thesis is concluded by a series of general recommendations for forensic handwriting examiners in forensic science, specifically for the expertise of signatures on paintings. These recommendations stem from the exhaustive review of the literature and the issues exposed from this review and can also be applied to the traditional examination of signatures (on paper). Part II - Experimental part Chapter 7 describes and defines the sampling, extraction and analysis phases of the research. The sampling stage of artists' signatures and their respective simulations are presented, followed by the steps that were undertaken to extract and determine sets of characteristics, specific to each artist, that describe their signatures. The method is based on a study of five artists and a group of individuals acting as forgers for the sake of this study. Finally, the analysis procedure of these characteristics to assess of the strength of evidence, and based on a Bayesian reasoning process, is presented. Chapter 8 outlines the results concerning both the artist and simulation corpuses after their optical observation, followed by the results of the analysis phase of the research. The feature selection process and the likelihood ratio evaluation are the main themes that are addressed. The discrimination power between both corpuses is illustrated through multivariate analysis. Part III - Discussion Chapter 9 discusses the materials, the methods, and the obtained results of the research. The opportunities, but also constraints and limits, of the developed method are exposed. Future works that can be carried out subsequent to the results of the study are also presented. Chapter 10, the last chapter of this thesis, proposes a strategy to incorporate the model developed in the last chapters into the traditional signature expertise procedures. Thus, the strength of this expertise is discussed in conjunction with the traditional conclusions reached by forensic handwriting examiners in forensic science. Finally, this chapter summarizes and advocates a list of formal recommendations for good practices for handwriting examiners. In conclusion, the research highlights the interdisciplinary aspect of signature examination of signatures on paintings. The current state of knowledge of the judicial quality of art experts, along with the scientific and historical analysis of paintings and signatures, are overviewed to give the reader a feel of the different factors that have an impact on this particular subject. The temperamental acceptance of forensic signature analysis in court, also presented in the state of the art, explicitly demonstrates the necessity of a better recognition of signature expertise by courts of law. This general acceptance, however, can only be achieved by producing high quality results through a well-defined examination process. This research offers an original approach to attribute a painted signature to a certain artist: for the first time, a probabilistic model used to measure the discriminative potential between authentic and simulated painted signatures is studied. The opportunities and limits that lie within this method of scientifically establishing the authorship of signatures on works of art are thus presented. In addition, the second key contribution of this work proposes a procedure to combine the developed method into that used traditionally signature experts in forensic science. Such an implementation into the holistic traditional signature examination casework is a large step providing the forensic, judicial and art communities with a solid-based reasoning framework for the examination of signatures on paintings. The framework and preliminary results associated with this research have been published (Montani, 2009a) and presented at international forensic science conferences (Montani, 2009b; Montani, 2012).