920 resultados para ORDER-DISORDER TRANSITION


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Knowledge Exchange examined different routes in achieving the vision of 'having a layer of scholarly and scientific content openly available in the internet'. One of these routes involves exploring new developments in the future of publishing. Work is being undertaken investigating interesting alternative business models which could contribute to the transition to open access. In this light KE has commissioned a study investigating whether submission fees could play a role in a business model for Open Access journals. The general conclusion of the report bearing the title ‘Submission Fees a tool in the transition to open access?', written by Mark Ware, is that there are benefits to publishers in certain cases to switch to a model in which an author pays a fee when submitting an article. Especially journals with a high rejection rate might be interested in combining submission fees with article processing charges in order to make the transition to open access easier. In certain disciplines, notably economic and finance journals and in some areas of the experimental life sciences, submission fees are already common. Overall there seems to be an interest in the model but the risks, particularly those involved in any transition, are seen by the publishers to outweigh the perceived benefits. There is also a problem in that the advantages offered by submission fees are often general benefits that might improve the system but do not provide publishers and authors with direct incentives to change to open access. To support transition funders, institutions and publication funds could make it clear that submission fees would be an allowable cost. At present this is often unclear in their policies. Author acceptance of submission fees is critical to its success. It is an observable fact that authors will accept them in some circumstances. Author acceptance would require further study though. Based on the interviews and the modelling in the study one model in particular is regarded as the most suitable way to meet the current requirements (i.e. to strengthen open access to research publications). In this model authors pay a submission fee plus an Article Processing Fee and the article is subsequently made available in open access. Both fees are set at levels that balance acceptability with the author community with securing a meaningful mix of revenues for the Publisher.

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A small percentage of women present with diagnosed PTSD post childbirth; however, though this an area of increasing research and clinical interest generally, little is known about PTSD in relation to perinatal bereavement. Health professionals must however be aware of the mechanisms and models of loss following perinatal bereavement in order to identify potential mental health phenomena which may be implicated in the development of PTSD symptomology. Understanding the predictive factors which may give early warning signs is an important component of the clinical evidence base. This chapter discusses mechanisms, models, and risk factors in relation to perinatal bereavement and the development of PTSD.

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Despite record-setting performance demonstrated by superconducting Transition Edge Sensors (TESs) and growing utilization of the technology, a theoretical model of the physics governing TES devices superconducting phase transition has proven elusive. Earlier attempts to describe TESs assumed them to be uniform superconductors. Sadleir et al. 2010 shows that TESs are weak links and that the superconducting order parameter strength has significant spatial variation. Measurements are presented of the temperature T and magnetic field B dependence of the critical current Ic measured over 7 orders of magnitude on square Mo/Au bilayers ranging in length from 8 to 290 microns. We find our measurements have a natural explanation in terms of a spatially varying order parameter that is enhanced in proximity to the higher transition temperature superconducting leads (the longitudinal proximity effect) and suppressed in proximity to the added normal metal structures (the lateral inverse proximity effect). These in-plane proximity effects and scaling relations are observed over unprecedentedly long lengths (in excess of 1000 times the mean free path) and explained in terms of a Ginzburg-Landau model. Our low temperature Ic(B) measurements are found to agree with a general derivation of a superconducting strip with an edge or geometric barrier to vortex entry and we also derive two conditions that lead to Ic rectification. At high temperatures the Ic(B) exhibits distinct Josephson effect behavior over long length scales and following functional dependences not previously reported. We also investigate how film stress changes the transition, explain some transition features in terms of a nonequilibrium superconductivity effect, and show that our measurements of the resistive transition are not consistent with a percolating resistor network model.

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The main task is to analyze the state of the art of grating couplers production and low-cost polymer substrates. Then to provide a recommendation of a new or adapted process for the production of metallic gratings on polymer sheets, based on a Failure Mode and Effect Analysis (FMEA). In order to achieve that, this thesis is divided into four chapters. After the first introductory chapter, the second section provides details about the state-of-the-art in optical technology platforms with focus on polymers and their main features for the aimed application, such as flexibility, low cost and roll to roll compatibility. It defines then the diffraction gratings and their specifications and closes with the explanation of adhesion mechanisms of inorganic materials on polymer substrates. The third chapter discusses processing of grating couplers. It introduces the basic fabrication methods and details a selection of current fabrication schemes found in literature with an assessment of their potential use for the desired application. The last chapter is a FMEA analysis of the retained fabrication process, called Flip and Fuse, in order to check its capability to realize the grating structure.

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Résumé : Introduction : Au Québec, jusqu’à l’âge de 21 ans, les enfants et adolescents ayant une déficience intellectuelle (DI) profonde ont des services de pédiatrie adaptés et l’opportunité de fréquenter des écoles spécialisées publiques. Toutefois, au-delà de cet âge, l’accès à ces services spécialisés est plus limité : le financement pour la fréquentation scolaire cesse et les jeunes adultes transfèrent des services de santé pédiatriques vers le secteur adulte. Malgré la mise en place de solutions visant à faciliter cette transition, des difficultés tendent à persister, une situation pouvant avoir des effets négatifs considérables au niveau de la personne ayant un handicap et de sa famille. Cependant, peu d’études se sont intéressées aux facteurs qui influencent le vécu de la transition vers la vie adulte des familles de jeunes personnes présentant une DI profonde, rendant difficile l’adaptation des programmes déjà existants de planification de la transition à la réalité de ces familles. Objectif : Ce projet vise à décrire les besoins des personnes présentant une DI profonde et de leur famille lors de la transition vers la vie adulte, en décrivant le vécu des parents lors de cette période et les facteurs qui l’influencent, ainsi qu’en explorant les pistes de solution à mettre en place. Méthodologie : Afin de réaliser cette étude qualitative, un devis descriptif interprétatif a été choisi. Deux entrevues semi-dirigées individuelles ont été réalisées auprès de quatorze parents, la deuxième entrevue permettant de valider et d’approfondir les résultats à l’aide d’un résumé de la première rencontre. Résultats : Plusieurs facteurs multisystémiques de l’ordre du soutien matériel, informatif, cognitif et affectif semblent influencer la transition vers la vie adulte. Ces différents facteurs contribuent au vécu particulièrement difficile des familles, qui vivent beaucoup d’anxiété et de frustration face au peu de soutien qui leur est offert. Plusieurs idées intéressantes ont été proposées par les parents pour répondre à ce manque de soutien, autant au plan du partage des connaissances, de l’amélioration de la collaboration inter-établissement que du soutien psychologique. Conclusion : Cette étude souligne l’importance d’impliquer l’ensemble des acteurs œuvrant auprès du jeune adulte et de sa famille dans la planification de la transition. La compréhension de la réalité des personnes avec une DI profonde et de leur famille devrait permettre de développer des interventions concrètes leur étant destinées dans de futurs projets.

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This thesis is an investigation of structural brain abnormalities, as well as multisensory and unisensory processing deficits in autistic traits and Autism Spectrum Disorder (ASD). To achieve this, structural and functional magnetic resonance imaging (fMRI) and psychophysical techniques were employed. ASD is a neurodevelopmental condition which is characterised by the social communication and interaction deficits, as well as repetitive patterns of behaviour, interests and activities. These traits are thought to be present in a typical population. The Autism Spectrum Quotient questionnaire (AQ) was developed to assess the prevalence of autistic traits in the general population. Von dem Hagen et al. (2011) revealed a link between AQ with white matter (WM) and grey matter (GM) volume (using voxel-based-morphometry). However, their findings revealed no difference in GM in areas associated with social cognition. Cortical thickness (CT) measurements are known to be a more direct measure of cortical morphology than GM volume. Therefore, Chapter 2 investigated the relationship between AQ scores and CT in the same sample of participants. This study showed that AQ scores correlated with CT in the left temporo-occipital junction, left posterior cingulate, right precentral gyrus and bilateral precentral sulcus, in a typical population. These areas were previously associated with structural and functional differences in ASD. Thus the findings suggest, to some extent, autistic traits are reflected in brain structure - in the general population. The ability to integrate auditory and visual information is crucial to everyday life, and results are mixed regarding how ASD influences audiovisual integration. To investigate this question, Chapter 3 examined the Temporal Integration Window (TIW), which indicates how precisely sight and sound need to be temporally aligned so that a unitary audiovisual event can be perceived. 26 adult males with ASD and 26 age and IQ-matched typically developed males were presented with flash-beep (BF), point-light drummer, and face-voice (FV) displays with varying degrees of asynchrony and asked to make Synchrony Judgements (SJ) and Temporal Order Judgements (TOJ). Analysis of the data included fitting Gaussian functions as well as using an Independent Channels Model (ICM) to fit the data (Garcia-Perez & Alcala-Quintana, 2012). Gaussian curve fitting for SJs showed that the ASD group had a wider TIW, but for TOJ no group effect was found. The ICM supported these results and model parameters indicated that the wider TIW for SJs in the ASD group was not due to sensory processing at the unisensory level, but rather due to decreased temporal resolution at a decisional level of combining sensory information. Furthermore, when performing TOJ, the ICM revealed a smaller Point of Subjective Simultaneity (PSS; closer to physical synchrony) in the ASD group than in the TD group. Finding that audiovisual temporal processing is different in ASD encouraged us to investigate the neural correlates of multisensory as well as unisensory processing using functional magnetic resonance imaging fMRI. Therefore, Chapter 4 investigated audiovisual, auditory and visual processing in ASD of simple BF displays and complex, social FV displays. During a block design experiment, we measured the BOLD signal when 13 adults with ASD and 13 typically developed (TD) age-sex- and IQ- matched adults were presented with audiovisual, audio and visual information of BF and FV displays. Our analyses revealed that processing of audiovisual as well as unisensory auditory and visual stimulus conditions in both the BF and FV displays was associated with reduced activation in ASD. Audiovisual, auditory and visual conditions of FV stimuli revealed reduced activation in ASD in regions of the frontal cortex, while BF stimuli revealed reduced activation the lingual gyri. The inferior parietal gyrus revealed an interaction between stimulus sensory condition of BF stimuli and group. Conjunction analyses revealed smaller regions of the superior temporal cortex (STC) in ASD to be audiovisual sensitive. Against our predictions, the STC did not reveal any activation differences, per se, between the two groups. However, a superior frontal area was shown to be sensitive to audiovisual face-voice stimuli in the TD group, but not in the ASD group. Overall this study indicated differences in brain activity for audiovisual, auditory and visual processing of social and non-social stimuli in individuals with ASD compared to TD individuals. These results contrast previous behavioural findings, suggesting different audiovisual integration, yet intact auditory and visual processing in ASD. Our behavioural findings revealed audiovisual temporal processing deficits in ASD during SJ tasks, therefore we investigated the neural correlates of SJ in ASD and TD controls. Similar to Chapter 4, we used fMRI in Chapter 5 to investigate audiovisual temporal processing in ASD in the same participants as recruited in Chapter 4. BOLD signals were measured while the ASD and TD participants were asked to make SJ on audiovisual displays of different levels of asynchrony: the participants’ PSS, audio leading visual information (audio first), visual leading audio information (visual first). Whereas no effect of group was found with BF displays, increased putamen activation was observed in ASD participants compared to TD participants when making SJs on FV displays. Investigating SJ on audiovisual displays in the bilateral superior temporal gyrus (STG), an area involved in audiovisual integration (see Chapter 4), we found no group differences or interaction between group and levels of audiovisual asynchrony. The investigation of different levels of asynchrony revealed a complex pattern of results indicating a network of areas more involved in processing PSS than audio first and visual first, as well as areas responding differently to audio first compared to video first. These activation differences between audio first and video first in different brain areas are constant with the view that audio leading and visual leading stimuli are processed differently.

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Postmodernizm prezentuje postawę akceptacji Nieładu, Chaosu i Przypadku. Czy istnieje moż- liwość dialogu z taką postawą? Postmodernizm powstaje jako bunt na pograniczu filozofii i estetyki. Kontestuje zastany Ład. Sprzeciwia się kartezjańskiemu Cogito ergo sum oraz podziałowi na res cogitans i res extensa. Jest to ruch kulturowy, który nie ma jeszcze swojego ostatecznego wyrazu. Jest on ciągle postrzegany jako proces przechodzenia od starego do nowego Ładu. Taki brak dookreślenia budzi niepokój i sprzeciw. Teologia fundamentalna jest badaniem granic i dialogu. Stoi na progu, więc ma obowiązek rozeznać ludzki niepokój w akceptacji otaczającego świata. Musimy zapytać, dlaczego człowiek akceptuje ten Nieład?

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Over the past years, several studies have raised concerns about the possible interactions between methane hydrate decomposition and external change. To carry out such an investigation, it is essential to characterize the baseline dynamics of gas hydrate systems related to natural geological and sedimentary processes. This is usually treated through the analysis of sulfate-reduction coupled to anaerobic oxidation of methane (AOM). Here, we model sulfate reduction coupled with AOM as a two-dimensional (2D) problem including, advective and diffusive transport. This is applied to a case study from a deep-water site off Nigeria’s coast where lateral methane advection through turbidite layers was suspected. We show by analyzing the acquired data in combination with computational modeling that a two-dimensional approach is able to accurately describe the recent past dynamics of such a complex natural system. Our results show that the sulfate-methane-transition-zone (SMTZ) is not a vertical barrier for dissolved sulfate and methane. We also show that such a modeling is able to assess short timescale variations in the order of decades to centuries.

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Part 4: Transition Towards Product-Service Systems

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Certaines recherches ont investigué le traitement visuel de bas et de plus hauts niveaux chez des personnes neurotypiques et chez des personnes ayant un trouble du spectre de l’autisme (TSA). Cependant, l’interaction développementale entre chacun de ces niveaux du traitement visuel n’est toujours pas bien comprise. La présente thèse a donc deux objectifs principaux. Le premier objectif (Étude 1) est d’évaluer l’interaction développementale entre l’analyse visuelle de bas niveaux et de niveaux intermédiaires à travers différentes périodes développementales (âge scolaire, adolescence et âge adulte). Le second objectif (Étude 2) est d’évaluer la relation fonctionnelle entre le traitement visuel de bas niveaux et de niveaux intermédiaires chez des adolescents et des adultes ayant un TSA. Ces deux objectifs ont été évalué en utilisant les mêmes stimuli et procédures. Plus précisément, la sensibilité de formes circulaires complexes (Formes de Fréquences Radiales ou FFR), définies par de la luminance ou par de la texture, a été mesurée avec une procédure à choix forcés à deux alternatives. Les résultats de la première étude ont illustré que l’information locale des FFR sous-jacents aux processus visuels de niveaux intermédiaires, affecte différemment la sensibilité à travers des périodes développementales distinctes. Plus précisément, lorsque le contour est défini par de la luminance, la performance des enfants est plus faible comparativement à celle des adolescents et des adultes pour les FFR sollicitant la perception globale. Lorsque les FFR sont définies par la texture, la sensibilité des enfants est plus faible comparativement à celle des adolescents et des adultes pour les conditions locales et globales. Par conséquent, le type d’information locale, qui définit les éléments locaux de la forme globale, influence la période à laquelle la sensibilité visuelle atteint un niveau développemental similaire à celle identifiée chez les adultes. Il est possible qu’une faible intégration visuelle entre les mécanismes de bas et de niveaux intermédiaires explique la sensibilité réduite des FFR chez les enfants. Ceci peut être attribué à des connexions descendantes et horizontales immatures ainsi qu’au sous-développement de certaines aires cérébrales du système visuel. Les résultats de la deuxième étude ont démontré que la sensibilité visuelle en autisme est influencée par la manipulation de l’information locale. Plus précisément, en présence de luminance, la sensibilité est seulement affectée pour les conditions sollicitant un traitement local chez les personnes avec un TSA. Cependant, en présence de texture, la sensibilité est réduite pour le traitement visuel global et local. Ces résultats suggèrent que la perception de formes en autisme est reliée à l’efficacité à laquelle les éléments locaux (luminance versus texture) sont traités. Les connexions latérales et ascendantes / descendantes des aires visuelles primaires sont possiblement tributaires d’un déséquilibre entre les signaux excitateurs et inhibiteurs, influençant ainsi l’efficacité à laquelle l’information visuelle de luminance et de texture est traitée en autisme. Ces résultats supportent l’hypothèse selon laquelle les altérations de la perception visuelle de bas niveaux (local) sont à l’origine des atypies de plus hauts niveaux chez les personnes avec un TSA.

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In this dissertation, I explore information practices during life transition in the context of immigration. This study aims to understand how their unique personal, social, and life contexts shape immigration experiences, and how these diverse contexts are related to various information practices that they engage in to resolve daily information needs and achieve immigration goals. In my study I examined daily information needs and acquisition of Korean immigrant women. Data were collected through two interview sessions, diary entries on everyday information seeking up to three weeks, post-diary debriefing interviews to reveal contexts surrounding information practices, and observation sessions. My study shows that one’s accumulated experiences with information-related situations shape the person’s attitudes toward diverse information resources and habitual information practices. Both personal and social contexts surrounding immigrant women change during life transition and shape how they interpret their immigration experiences, what information they need to deal with both daily and long-term goals, and how they modify their information practices to obtain the relevant information in an unfamiliar information environment. Also, life transition of immigration entails changes in immigrant women’s social roles, which engender their daily responsibilities in the new society. These daily responsibilities motivate immigrant women’s everyday interactions with a variety of communities in order to exchange information and conduct their social roles in the new sociocultural environment. While immigrant women had common information needs around culture learning, social roles and associated responsibilities explain differences in their differing information needs and tend to direct daily information practices. The advancement of ICTs allows immigrant women to conduct their social roles in a remote city as well as to maintain multiple connections with both the heritage and host society. Limited cultural knowledge influences immigrant women’s evaluation and use of the obtained information as well as their acquisition of relevant information. This study provides understandings on the role of information during life transition as well as Korean immigrant women’s information practices.

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The World Order is a concept in constant mutation that has lost a lot of what characterized it when it was established with the Peace of Westphalia. The conflicts also went through changes. They lost its State distinctiveness and became dispersed and chaotic due to multipolarization. These two concepts share some connections and both dissociated from their traditional definition. This paper aims to establish a connection between the contemporary World Order and the conflicts evolution. The threats to the stability of the World Order contribute to the current disorder and reflects how the conflicts distanced themselves from the clausewitzian battles. To understand how these threats impact the World Order stability and evince the conflicts evolution two cases of study were selected: the nuclear proliferation in Iran and the crisis in Ukraine. These two examples will help establishing the link between the contemporary World Disorder and the conflicts evolution.

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This thesis presents studies of the role of disorder in non-equilibrium quantum systems. The quantum states relevant to dynamics in these systems are very different from the ground state of the Hamiltonian. Two distinct systems are studied, (i) periodically driven Hamiltonians in two dimensions, and (ii) electrons in a one-dimensional lattice with power-law decaying hopping amplitudes. In the first system, the novel phases that are induced from the interplay of periodic driving, topology and disorder are studied. In the second system, the Anderson transition in all the eigenstates of the Hamiltonian are studied, as a function of the power-law exponent of the hopping amplitude.

In periodically driven systems the study focuses on the effect of disorder in the nature of the topology of the steady states. First, we investigate the robustness to disorder of Floquet topological insulators (FTIs) occurring in semiconductor quantum wells. Such FTIs are generated by resonantly driving a transition between the valence and conduction band. We show that when disorder is added, the topological nature of such FTIs persists as long as there is a gap at the resonant quasienergy. For strong enough disorder, this gap closes and all the states become localized as the system undergoes a transition to a trivial insulator.

Interestingly, the effects of disorder are not necessarily adverse, disorder can also induce a transition from a trivial to a topological system, thereby establishing a Floquet Topological Anderson Insulator (FTAI). Such a state would be a dynamical realization of the topological Anderson insulator. We identify the conditions on the driving field necessary for observing such a transition. We realize such a disorder induced topological Floquet spectrum in the driven honeycomb lattice and quantum well models.

Finally, we show that two-dimensional periodically driven quantum systems with spatial disorder admit a unique topological phase, which we call the anomalous Floquet-Anderson insulator (AFAI). The AFAI is characterized by a quasienergy spectrum featuring chiral edge modes coexisting with a fully localized bulk. Such a spectrum is impossible for a time-independent, local Hamiltonian. These unique characteristics of the AFAI give rise to a new topologically protected nonequilibrium transport phenomenon: quantized, yet nonadiabatic, charge pumping. We identify the topological invariants that distinguish the AFAI from a trivial, fully localized phase, and show that the two phases are separated by a phase transition.

The thesis also present the study of disordered systems using Wegner's Flow equations. The Flow Equation Method was proposed as a technique for studying excited states in an interacting system in one dimension. We apply this method to a one-dimensional tight binding problem with power-law decaying hoppings. This model presents a transition as a function of the exponent of the decay. It is shown that the the entire phase diagram, i.e. the delocalized, critical and localized phases in these systems can be studied using this technique. Based on this technique, we develop a strong-bond renormalization group that procedure where we solve the Flow Equations iteratively. This renormalization group approach provides a new framework to study the transition in this system.

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It has been recently shown that the double exchange Hamiltonian, with weak antiferromagnetic interactions, has a richer variety of first- and second-order transitions than previously anticipated, and that such transitions are consistent with the magnetic properties of manganites. Here we present a thorough discussion of the variational mean-field approach that leads to these results. We also show that the effect of the Berry phase turns out to be crucial to produce first-order paramagnetic-ferromagnetic transitions near half filling with transition temperatures compatible with the experimental situation. The computation relies on two crucial facts: the use of a mean-field ansatz that retains the complexity of a system of electrons with off-diagonal disorder, not fully taken into account by the mean-field techniques, and the small but significant antiferromagnetic superexchange interaction between the localized spins.