986 resultados para Evaluate image retention


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This article enquires into the causes of union growth and decline by analysing flows in and out of membership at the level of 70 Swiss union locals over 2006-2008. Gross flows in union membership are much larger than the resulting net changes: annual membership turnover of 10 per cent is a surprisingly constant feature across unions. Net changes in membership are primarily determined by inflows: successful and languishing union locals differ in their entry rates, whereas exit rates are similar. Variance in union locals' entry rates is not usefully explained by the labour market context, but by differences in union strategy.

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Grade retention practices are at the forefront of the educational debate. In this paper, we use PISA 2009 data for Spain to measure the effect of grade retention on students’ achievement. One important problem when analyzing this question is that school outcomes and the propensity to repeat a grade are likely to be determined simultaneously. We address this problem by estimating a Switching Regression Model. We …find that grade retention has a negative impact on educational outcomes, but we confi…rm the importance of endogenous selection, which makes observed differences between repeaters and non-repeaters appear 14.6% lower than they actually are. The effect on PISA scores of repeating is much smaller (-10% of non-repeaters’ average) than the counterfactual reduction that non-repeaters would suffer had they been retained as repeaters (-24% of their average). Furthermore, those who repeated a grade during primary education suffered more than those who repeated a grade of secondary school, although the effect of repeating at both times is, as expected, much larger.

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Problématique: Pourquoi la mise en scène complexe du Timée-Critias avec ses contextes spatio-temporels emboîtés et ses narrations enchâssées? Quelle est la fonction (pragmatique et argumentative) du discours cosmogonique et anthropogonique de Timée intercalé entre le résumé du récit de l'Atlantide dans le prologue du Timée et la narration même de ce récit dans le Critias! Quel est le rapport entre les discours des deux protagonistes et celui de Socrate sur la cité idéale dans la République? Voilà les principales questions auxquelles cette thèse essaie de répondre. Grâce à une approche discursive et sémio-narrative, elle cherche à montrer la fonction pragmatique et la cohérence narrative et sémantique du double dialogue tout en tenant compte des visions du monde divergentes et même contradictoires des deux protagonistes. Elle essaie de comprendre comment les deux, l'un d'origine italique, l'autre Athénien, dans un contexte énonciatif donné et sur la base de leurs conceptions culturelles et «scientifiques» - sur l'homme et sur le monde - et de leurs idées «philosophiques» - sur l'être, le devenir et la connaissance - produisent des discours de signification différente mais traitant tous deux de la genèse, que ce soit celle du monde, de l'homme et des cités. Elle propose en outre de lire le Timée-Critias à la fois comme une continuation et une réécriture de la République: non seulement les trois dialogues ont le même sujet (la meilleure cité), mais ils se caractérisent par des parallèles dans la situation dramatique et énonciative et dans la manière dont se développe la narration. Plan: Les deux premiers chapitres examinent comment les performances discursives de Timée et de Critias se mettent en place dans le prologue, en prêtant une attention particulière aux aspects dramatiques et énonciatifs, mais aussi poétiques et narratifs (énonciateurs/narrateurs et leurs destinataires, fonction et genre des discours résumés et annoncés). Les troisième et quatrième chapitres, consacrés respectivement au long discours de Timée et à celui de Critias dans le dialogue homonyme, comparent d'abord les deux discours aux Hymnes homériques, à la Théogonie d'Hésiode et à la poésie généalogique afin de mieux saisir la fonction pragmatique et la composition de l'ensemble du Timée-Critias-, puis, à partir des principes ontologiques et épistémologiques explicités dans les proèmes, ils se proposent de dégager, en suivant de près la narration, les conceptions cosmologiques, anthropologiques et épistémologiques des deux protagonistes et de voir comment elles déterminent la production et l'énonciation de leurs discours. Enfin, le dernier chapitre reprend certains éléments essentiels étudiés précédemment en élargissant la perspective à la République et à son rapport intertextuel avec le Timée- Critias: il met en regard les contextes énonciatifs et dramatiques et la problématique des deux oeuvres (le rôle des personnages, la question de la réalisation de la meilleure cité), le discours de Timée et les livres six et sept (la khóra et Yagathón, le statut du discours vraisemblable et l'analogie de la ligne), ainsi que le Critias et les livres huit et dix (la dégénérescence de l'Atlantide et de la meilleure cité, la poésie «mimétique» de Critias et celle des poètes critiquée par Socrate).

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In the State of Campeche, Mexico, zoonotic cutaneous leishmaniasis is mainly due to Leishmania (L.) mexicana. The parasite population is maintained in a mammalian species, a reservoir in which the ideal course of infection should be long and relatively nonpathogenic. The objective of the present study was to document the retention of L. (L.) mexicana in 29 naturally infected rodents. These cricetids lived in captivity for up to two years and were tested monthly for the presence of the parasite, by cultures of needle aspirates from the base of the tail. Peromyscus yucatanicus and Ototylomys phyllotis were incriminated as the primary reservoir hosts. The finding that the multiplication of parasites in P. yucatanicus might be triggered by temperature, suggests that this animal would be a good choice for further research on L. (L.) mexicana.

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The effect of copper (Cu) filtration on image quality and dose in different digital X-ray systems was investigated. Two computed radiography systems and one digital radiography detector were used. Three different polymethylmethacrylate blocks simulated the pediatric body. The effect of Cu filters of 0.1, 0.2, and 0.3 mm thickness on the entrance surface dose (ESD) and the corresponding effective doses (EDs) were measured at tube voltages of 60, 66, and 73 kV. Image quality was evaluated in a contrast-detail phantom with an automated analyzer software. Cu filters of 0.1, 0.2, and 0.3 mm thickness decreased the ESD by 25-32%, 32-39%, and 40-44%, respectively, the ranges depending on the respective tube voltages. There was no consistent decline in image quality due to increasing Cu filtration. The estimated ED of anterior-posterior (AP) chest projections was reduced by up to 23%. No relevant reduction in the ED was noted in AP radiographs of the abdomen and pelvis or in posterior-anterior radiographs of the chest. Cu filtration reduces the ESD, but generally does not reduce the effective dose. Cu filters can help protect radiosensitive superficial organs, such as the mammary glands in AP chest projections.

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The thesis at hand is concerned with the spatio-temporal brain mechanisms of visual food perception as investigated by electrical neuroimaging. Due to the increasing prevalence of obesity and its associated challenges for public health care, there is a need to better understand behavioral and brain processes underlying food perception and food-based decision-making. The first study (Study A) of this thesis was concerned with the role of repeated exposure to visual food cues. In our everyday lives we constantly and repeatedly encounter food and these exposures influence our food choices and preferences. In Study A, we therefore applied electrical neuroimaging analyses of visual evoked potentials to investigate the spatio-temporal brain dynamics linked to the repeated viewing of high- and low-energy food cues (published manuscript: "The role of energetic value in dynamic brain response adaptation during repeated food image viewing" (Lietti et al., 2012)). In this study, we found that repetitions differentially affect behavioral and brain mechanisms when high-energy, as opposed to low-energy foods and non-food control objects, were viewed. The representation of high-energy food remained invariant between initial and repeated exposures indicating that the sight of high-energy dense food induces less behavioral and neural adaptation than the sight of low-energy food and non-food control objects. We discuss this finding in the context of the higher salience (due to greater motivation and higher reward or hedonic valuation) of energy- dense food that likely generates a more mnemonically stable representation. In turn, this more invariant representation of energy-dense food is supposed to (partially) explain why these foods are over-consumed despite of detrimental health consequences. In Study Β we investigated food responsiveness in patients who had undergone Roux-en-Y gastric bypass surgery to overcome excessive obesity. This type of gastric bypass surgery is not only known to alter food appreciation, but also the secretion patterns of adipokines and gut peptides. Study Β aimed at a comprehensive and interdisciplinary investigation of differences along the gut-brain axis in bypass-operated patients as opposed to weight-matched non-operated controls. On the one hand, the spatio-temporal brain dynamics to the visual perception of high- vs. low-energy foods under differing states of motivation towards food intake (i.e. pre- and post-prandial) were assessed and compared between groups. On the other hand, peripheral gut hormone measures were taken in pre- and post-prandial nutrition state and compared between groups. In order to evaluate alterations in the responsiveness along the gut-brain-axis related to gastric bypass surgery, correlations between both measures were compared between both participant groups. The results revealed that Roux-en- Y gastric bypass surgery alters the spatio-temporal brain dynamics to the perception of high- and low-energy food cues, as well as the responsiveness along the gut-brain-axis. The potential role of these response alterations is discussed in relation to previously observed changes in physiological factors and food intake behavior post-Roux-en-Y gastric bypass surgery. By doing so, we highlight potential behavioral, neural and endocrine (i.e. gut hormone) targets for the future development of intervention strategies for deviant eating behavior and obesity. Together, the studies showed that the visual representation of foods in the brain is plastic and that modulations in neural activity are already noted at early stages of visual processing. Different factors of influence such as a repeated exposure, Roux-en-Y gastric bypass surgery, motivation (nutrition state), as well as the energy density of the visually perceived food were identified. En raison de la prévalence croissante de l'obésité et du défi que cela représente en matière de santé publique, une meilleure compréhension des processus comportementaux et cérébraux liés à la nourriture sont nécessaires. En particulier, cette thèse se concentre sur l'investigation des mécanismes cérébraux spatio-temporels liés à la perception visuelle de la nourriture. Nous sommes quotidiennement et répétitivement exposés à des images de nourriture. Ces expositions répétées influencent nos choix, ainsi que nos préférences alimentaires. La première étude (Study A) de cette thèse investigue donc l'impact de ces exposition répétée à des stimuli visuels de nourriture. En particulier, nous avons comparé la dynamique spatio-temporelle de l'activité cérébrale induite par une exposition répétée à des images de nourriture de haute densité et de basse densité énergétique. (Manuscrit publié: "The role of energetic value in dynamic brain response adaptation during repeated food image viewing" (Lietti et al., 2012)). Dans cette étude, nous avons pu constater qu'une exposition répétée à des images représentant de la nourriture de haute densité énergétique, par opposition à de la nourriture de basse densité énergétique, affecte les mécanismes comportementaux et cérébraux de manière différente. En particulier, la représentation neurale des images de nourriture de haute densité énergétique est similaire lors de l'exposition initiale que lors de l'exposition répétée. Ceci indique que la perception d'images de nourriture de haute densité énergétique induit des adaptations comportementales et neurales de moindre ampleur par rapport à la perception d'images de nourriture de basse densité énergétique ou à la perception d'une « catégorie contrôle » d'objets qui ne sont pas de la nourriture. Notre discussion est orientée sur les notions prépondérantes de récompense et de motivation qui sont associées à la nourriture de haute densité énergétique. Nous suggérons que la nourriture de haute densité énergétique génère une représentation mémorielle plus stable et que ce mécanisme pourrait (partiellement) être sous-jacent au fait que la nourriture de haute densité énergétique soit préférentiellement consommée. Dans la deuxième étude (Study Β) menée au cours de cette thèse, nous nous sommes intéressés aux mécanismes de perception de la nourriture chez des patients ayant subi un bypass gastrique Roux- en-Y, afin de réussir à perdre du poids et améliorer leur santé. Ce type de chirurgie est connu pour altérer la perception de la nourriture et le comportement alimentaire, mais également la sécrétion d'adipokines et de peptides gastriques. Dans une approche interdisciplinaire et globale, cette deuxième étude investigue donc les différences entre les patients opérés et des individus « contrôles » de poids similaire au niveau des interactions entre leur activité cérébrale et les mesures de leurs hormones gastriques. D'un côté, nous avons investigué la dynamique spatio-temporelle cérébrale de la perception visuelle de nourriture de haute et de basse densité énergétique dans deux états physiologiques différent (pre- et post-prandial). Et de l'autre, nous avons également investigué les mesures physiologiques des hormones gastriques. Ensuite, afin d'évaluer les altérations liées à l'intervention chirurgicale au niveau des interactions entre la réponse cérébrale et la sécrétion d'hormone, des corrélations entre ces deux mesures ont été comparées entre les deux groupes. Les résultats révèlent que l'intervention chirurgicale du bypass gastrique Roux-en-Y altère la dynamique spatio-temporelle de la perception visuelle de la nourriture de haute et de basse densité énergétique, ainsi que les interactions entre cette dernière et les mesures périphériques des hormones gastriques. Nous discutons le rôle potentiel de ces altérations en relation avec les modulations des facteurs physiologiques et les changements du comportement alimentaire préalablement déjà démontrés. De cette manière, nous identifions des cibles potentielles pour le développement de stratégies d'intervention future, au niveau comportemental, cérébral et endocrinien (hormones gastriques) en ce qui concerne les déviances du comportement alimentaire, dont l'obésité. Nos deux études réunies démontrent que la représentation visuelle de la nourriture dans le cerveau est plastique et que des modulations de l'activité neurale apparaissent déjà à un stade très précoce des mécanismes de perception visuelle. Différents facteurs d'influence comme une exposition repetee, le bypass gastrique Roux-en-Y, la motivation (état nutritionnel), ainsi que la densité énergétique de la nourriture qui est perçue ont pu être identifiés.

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The tourism consumer’s purchase decision process is, to a great extent, conditioned by the image the tourist has of the different destinations that make up his or her choice set. In a highly competitive international tourist market, those responsible for destinations’ promotion and development policies seek differentiation strategies so that they may position the destinations in the most suitable market segments for their product in order to improve their attractiveness to visitors and increase or consolidate the economic benefits that tourism activity generates in their territory. To this end, the main objective we set ourselves in this paper is the empirical analysis of the factors that determine the image formation of Tarragona city as a cultural heritage destination. Without a doubt, UNESCO’s declaration of Tarragona’s artistic and monumental legacies as World Heritage site in the year 2000 meant important international recognition of the quality of the cultural and patrimonial elements offered by the city to the visitors who choose it as a tourist destination. It also represents a strategic opportunity to boost the city’s promotion of tourism and its consolidation as a unique destination given its cultural and patrimonial characteristics. Our work is based on the use of structured and unstructured techniques to identify the factors that determine Tarragona’s tourist destination image and that have a decisive influence on visitors’ process of choice of destination. In addition to being able to ascertain Tarragona’s global tourist image, we consider that the heterogeneity of its visitors requires a more detailed study that enables us to segment visitor typology. We consider that the information provided by these results may prove of great interest to those responsible for local tourism policy, both when designing products and when promoting the destination.

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PURPOSE: To evaluate the effects of recent advances in magnetic resonance imaging (MRI) radiofrequency (RF) coil and parallel imaging technology on brain volume measurement consistency. MATERIALS AND METHODS: In all, 103 whole-brain MRI volumes were acquired at a clinical 3T MRI, equipped with a 12- and 32-channel head coil, using the T1-weighted protocol as employed in the Alzheimer's Disease Neuroimaging Initiative study with parallel imaging accelerations ranging from 1 to 5. An experienced reader performed qualitative ratings of the images. For quantitative analysis, differences in composite width (CW, a measure of image similarity) and boundary shift integral (BSI, a measure of whole-brain atrophy) were calculated. RESULTS: Intra- and intersession comparisons of CW and BSI measures from scans with equal acceleration demonstrated excellent scan-rescan accuracy, even at the highest acceleration applied. Pairs-of-scans acquired with different accelerations exhibited poor scan-rescan consistency only when differences in the acceleration factor were maximized. A change in the coil hardware between compared scans was found to bias the BSI measure. CONCLUSION: The most important findings are that the accelerated acquisitions appear to be compatible with the assessment of high-quality quantitative information and that for highest scan-rescan accuracy in serial scans the acquisition protocol should be kept as consistent as possible over time. J. Magn. Reson. Imaging 2012;36:1234-1240. ©2012 Wiley Periodicals, Inc.

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  Mid 1999 Investigation into cardiac surgery practice on children at Bristol Royal Infirmary. Dec 1999 Inquiry into organ retention in Alder Hey Children’s Hospital in Liverpool. May 1999: Contact from Our Lady’s Hosptial Crumlin re pathology and post mortem practice Dec 1999 PFJ meetings with Minister Apr 2000: Government Decision setting up Inquiry. Apr 2000: Ms Anne Dunne appointed Chairman. Feb 2001: Public Notice published, setting out terms of reference of Inquiry and inviting submissions. Mar 2001: Terms of Reference and Interpretation Published. Contact invited. “Six months N/A. Now 18 months” Jun 2001: Department commenced Discovery. Aug 2001: Memorandum on procedures received in Department. Sept 2002: 18 months time-frame had expired. Minister requested a meeting with Ms Anne Dunne. This happened in early September – Minister requested a progress report. 2 Oct 02 Ms Dunne’s progress report received by Minister – although substantial progress no definitive timeframe for completion of her work – a lot more work outstanding. Co-operation forthcoming from all parties 16 Oct 2002: Minister’s meeting with Parents for Justice – he assured them of his commitment to resolve any difficulties, but they decided to withdraw from the Inquiry process 2004: Minister calls on PFJ to co-operate. Chairman informs Minister that she has sufficient involvement of parents to conclude her report. Minister expects paediatric report by the end of the year

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Hepatozoon species are the most abundant hemoparasites of snakes. Its identification has been based mainly on the morphologic characterization of the gamonts in the peripheral blood of the vertebrate host and also of the cysts found in the internal organs of the vertebrate and invertebrate hosts. Using a computerized image analysis system, we studied five species of Hepatozoon from recently captured snakes in Botucatu, State of São Paulo, Brazil, to evaluate the importance of the morphology and morphometry of the gamonts for the characterization of Hepatozoon species and to analyze the morphologic changes induced in the erythrocytes by the parasite. The studied species were H. terzii of Boa constrictor amarali, Hepatozoon sp. of Crotalus durissusterrificus, H. philodryasi of Philodryas patagoniensis, and H. migonei and H. cyclagrasi of Hydrodynastes gigas. We observed three different groups, one of them including the species H. terzii, H. philodryasi and Hepatozoon sp. of C. durissus terrificus; and the other two consisting of H. migonei and H. cyclagrasi. Degree of alterations in the erythrocytes was variable and it may be useful for characterization of Hepatozoon species.