439 research outputs found

    Good Thoughts, Bad Thoughts? Investigating the Nature of the Wandering Mind and How to Capture It

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    This dissertation aims at painting a balanced picture of the wandering mind’s nature, strengthening an adaptive view of the phenomenon of drifting thoughts. First, negative consequences of drifting thoughts will be contrasted with positive ones, and I further aim to bring both sides of the medal more in line by focusing on thought-regulation processes. Previous insights will then be enriched by new contributions: I will introduce memory as a newly considered domain, which I found to benefit from mind-wandering processes. From a more methodological perspective and within the domains of creativity and problem-solving, I will not only take a look at possible further mind-wandering benefits, but also present a new research paradigm. This paradigm allows for the closer investigation of possibly thought-altering and intrusive effects of thought probes, the most widely applied mind-wandering assessment method. Thought probes ask participants about their current thoughts during a task and might thus modify the mind-wandering experience itself, thereby complicating the search for positive effects of the phenomenon. As such probes further rely on self-reports and thus contain a subjective component, I will finally report a review and validation study of eye-movement measures as objective mind-wandering indicators. Thus, this dissertation presents an investigation of the nature of the wandering mind as well as of subjective and objective thought-assessment methods

    Cross immunity protection and antibody-dependent enhancement in a distributed delay dynamic model

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    Dengue fever is endemic in tropical and subtropical countries, and certain important features of the spread of dengue fever continue to pose challenges for mathematical modelling. Here we propose a system of integro-differential equations (IDE) to study the disease transmission dynamics that involve multi-serotypes and cross immunity. Our main objective is to incorporate and analyze the effect of a general time delay term describing acquired cross immunity protection and the effect of antibody-dependent enhancement (ADE), both characteristics of Dengue fever. We perform qualitative analysis of the model and obtain results to show the stability of the epidemiologically important steady solutions that are completely determined by the basic reproduction number and the invasion reproduction number. We establish the global dynamics by constructing a suitable Lyapunov functional. We also conduct some numerical experiments to illustrate bifurcation structures, indicating the occurrence of periodic oscillations for a specific range of values of a key parameter representing ADE.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil (CAPES) - Finance Code 001 LIAM - Laboratory for Industrial and Applied Mathematics, Department of Mathematics and Statistics, York University-CA

    Positionsbestimmung Inklusion: Ziele und Handlungsansätze

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    Inklusion wird seit den letzten Jahren verstärkt diskutiert. Dennoch sind sowohl Begriff als auch die Herangehensweisen oft noch unscharf oder werden unterschiedlich interpretiert. Zudem sind die Idee der Inklusion und das Wissen über ihre Umsetzung in der breiten Öffentlichkeit bisher nur wenig bekannt

    Partitionierte Verfahren für Probleme der Fluid-Struktur Wechselwirkung

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    Die numerische Simulation der Wechselwirkung von Fluid und Struktur ist eine der großen Herausforderungen des Wissenschaftlichen Rechnens. Typische Beispiele für Fluid-Struktur Interaktion sind aeroelastische Probleme oder biomechanische Prozesse. Bei der Wechselwirkung von Strömung und Struktur handelt es sich oft um stark nichtlineare Probleme. Die Berechnung dieser Interaktionsprobleme erfordert die simultane Lösung der stark gekoppelten Bewegungsgleichungen. In dieser Arbeit werden partitionierte Verfahren zur Berechnung der Fluid-Struktur Interaktion betrachtet. Partitionierte Verfahren erlauben die Verwendung von effizienten Diskretisierungs- und Lösungsverfahren für jedes Teilproblem und unterstützen die Wiederverwendung von existierender und hochentwickelter Software. Das gekoppelte Problem wird bei partitionierten Verfahren durch ein gekoppeltes Lösungsverfahren berechnet, bei dem das Fluid- und das Strukturproblem getrennt voneinander gelöst werden und in jedem Zeitschritt bzw. in jeder Iteration des Kopplungsalgorithmus die Kopplungsgrößen ausgetauscht werden. Aus Stabilitäts- und Genauigkeitsgründen wird oft eine starke Kopplung gewählt. Bei diesem Ansatz muß in jedem Zeitschritt ein großes System von nichtlinearen gekoppelten Gleichungen mit Hilfe der (iterativen) Löser für die Teilprobleme gelöst werden. Dieses geschieht in den meisten Fällen mit Block-Gauß-Seidel- oder verwandten Relaxationsverfahren. Es existiert allerdings eine Forderung nach effizienteren stark gekoppelten Lösungsverfahren, da diese einfachen Methoden nicht immer konvergieren. Wir stellen in dieser Arbeit einen neuen Ansatz vor, dessen Grundlage ein approximatives Block-Newton Verfahren bildet. Wir demonstrieren das neu entwickelte Verfahren anhand von mehreren Beispielen und vergleichen seine Effizienz mit gestaffelten Verfahren und der Block-Gauß-Seidel Iteration.The numerical simulation of fluid-structure interaction problems is one of the great challenges in scientific computing. Typical examples for fluid-structure interaction arise in aero-elasticity or in bio-mechanics. Often, fluid-structure interaction problems are highly nonlinear coupled problems. The computation of those nonlinear fluid-structure interaction problems requires the simultaneous solution of the strongly coupled fluid and structural equations of motion. In this thesis, we consider partitioned methods for fluid-structure interaction, i.e. separate solvers are used for the fluid and the structure. Partitioned procedures allow the use of well established discretisation and solution methods for each subproblem. They also support the reuse of existing and highly developed software and offer a modular solution approach. In partitioned methods, the coupled problem is computed with a solution procedure where the fluid and the structure are separately solved and exchange data in every time-step or iteration of the coupling algorithm. This approach allows a smooth transition between `loose' and `strong' coupling. For stability and accuracy reasons, often a strong coupling has to be used. In this approach, we have to solve a large system of nonlinear equations with the use of the (iterative) solvers for the subsystems. Usually, this is done with Block-Gauss-Seidel or related relaxation methods. Nevertheless, there is a demand for more sophisticated solution methods as the simple methods do not always converge. We will introduce here an approximative Block-Newton method which is shown to be superior to the standard Block-iterative methods. We will demonstrate the new method for several two-dimensional applications and compare the efficiency with explicit partitioned methods and Block-Gauss-Seidel iterations

    Effect of General Cross-Immunity Protection and Antibody- Dependent Enhancement in Dengue Dynamics

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    A mathematical model to describe the dynamic of a multiserotype infectious disease at the population level is studied. Applied to dengue fever epidemiology, we analyse a mathematical model with time delay to describe the cross-immunity protection period, including a key parameter for the antibody-dependent enhancement (ADE) effect, the well-known features of dengue fever infection. Numerical experiments are performed to show the stability of the coexistence equilibrium, which is completely determined by the basic reproduction number and by the invasion reproduction number, as well as the bifurcation structures for different scenarios of dengue fever transmission in a population. The model shows a rich dynamical behavior, from fixed points and periodic oscillations up to chaotic behaviour with complex attractors.Laboratory for Industrial and Applied Mathematics (LIAM), Department of Mathematics and Statistics, York University, CA

    Symmetry in a multi-strain epidemiological model with distributed delay as a general cross-protection period and disease enhancement factor

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    Important biological features of viral infectious diseases caused by multiple agents with interacting strain dynamics continue to pose challenges for mathematical modelling development. Motivated by dengue fever epidemiology, we study a system of Integro-Differential Equations (IDE) considering strain structure of pathogens. Knowing that complex dynamics observed in dengue models are driven by the combination of two biological features, the temporary cross-immunity (TCI) and disease enhancement via the antibody-dependent enhancement process (ADE), our IDE system incorporates the TCI with a general time delay term, and the ADE effect by a constant factor to differentiate the susceptibility of individuals experiencing a primary or a secondary infection. Aiming at analysing the effect of the symmetry on dengue serotypes in the IDE framework, a detailed qualitative analysis of the model is performed and the instability of the coexistence steady state is shown using the perturbation theory approach. Numerical simulations identify the bifurcation structures and confirm the stability analysis. Results for the symmetric and asymmetric models are discussed

    Ambiguous Loss: The Impact of Absence An investigation of Boss’s Ambiguous Loss Theory and Implications for Wilderness-Based Healing

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    64 pagesThis research paper will explain the experience of Ambiguous Loss, a loss that is constructed by both the absence and presence of an individual, and then introduce an effective and impactful healing modality. This project intends to portray the difficulties surrounding losing someone ambiguously and the necessity to hold two seemingly incompatible realities - absence and presence - at the same time. The steps recognized in the healing of grief from loss and death, which is commonly experienced and understood in our world today, will be used to carefully distinguish how the experience of Ambiguous Loss is uniquely different. From the perspective of the person who is experiencing the loss, this paper will explore and substantiate the emotional complexity and state of inconclusiveness and confusion resulting from Ambiguous Loss. This paper will also present wilderness therapy as a promising modality that may uniquely support a process of acceptance and integration that is well-tailored for Ambiguous Loss. Wilderness therapy, and the impact of the raw natural setting, may be an instrumental modality for helping individuals process the unique grief that arises from Ambiguous Loss due to the expansive and complex nature of both this form of loss and the natural environment. Wilderness therapy may provide individuals a concrete, real-life surmountable challenge that creates a tangible rather than conceptual experience, beautifully countering the disorienting experience of Ambiguous Loss itself

    Association of atrial fibrillation and health-related quality of life in patients with ischemic stroke or TIA

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    Hintergrund/Ziele: Vorhofflimmern (VHF) verursacht etwa 15-20% aller ischämischen Schlaganfälle. Sowohl Patient:innen mit ischämischem Schlaganfall als auch VHF-Patient:innen sind in ihrer gesundheitsbezogenen Lebensqualität (HRQOL) eingeschränkt. Darüber hinaus können VHF-assoziierte Symptome eine Verminderung der HRQOL bedingen. Bisher gibt es nur wenig Information zur HRQOL von Patient:innen mit ischämischem Schlaganfall und VHF. Ziel dieser Arbeit ist es zu charakterisieren, ob VHF, die VHF-Symptomschwere und die Einnahme einer oralen Antikoagulation (OAK) mit der HRQOL bei Patient:innen mit ischämischen Schlaganfall oder transitorischer ischämischer Attacke (TIA) assoziiert sind. Methoden: Daten der “Impact of standardized MONitoring for Detection of Atrial Fibrillation in Ischemic Stroke (MonDAFIS)”-Studie und des „Berliner Vorhofflimmer Register“ (BVR) wurden ausgewertet. Beide Studien sind Prüfer-initiierte, prospektive, multizentrische Studien der Charité – Universitätsmedizin Berlin. In der MonDAFIS-Studie wurden 3470 Patient:innen mit akutem ischämischem Schlaganfall oder TIA ohne bekanntes VHF eingeschlossen. In der BVR-Studie wurden 1080 Patient:innen mit VHF und akutem ischämischem Schlaganfall oder TIA eingeschlossen. Die Daten zur HRQOL wurden mittels EQ-5D-3L Fragebogen, bestehend aus EQ-Index und EQ-VAS, zu mehreren Zeitpunkten erhoben. Die statistische Auswertung erfolgte mittels multivariabler linearer Regressionsmodelle. Neben der HRQOL zum Zeitpunkt des Studienbeginns wurde für soziodemographische Faktoren, Schlaganfallschwere, Vorerkrankungen, weitere kardiovaskuläre Ereignisse, VHF, Art und Persistenz der OAK, Symptomschwere des VHF (EHRA-Score) als auch für das Studienzentrum adjustiert. Ergebnisse: VHF-Patient:innen ohne OAK hatten ein Jahr nach Studieneinschluss eine niedrigere HRQOL als VHF-Patient:innen mit OAK (MonDAFIS: EQ-Index p=0,003; EQ-VAS p=0,042; BVR: EQ-VAS p=0,017). Nahmen VHF-Patient:innen eine OAK ein, so war die HRQOL vergleichbar hoch wie in der Patient:innengruppe ohne VHF und OAK (MonDAFIS: EQ-Index p=0,349; EQ-VAS p=0,624). Eine nicht-persistente OAK-Einnahme war nach 12 Monaten (BVR p<0,001) und im Verlauf bis zu 36 Monaten (BVR p<0,001) mit niedrigeren EQ-VAS Werten assoziiert. Zudem zeigte sich, dass Patient:innen mit symptomatischem VHF niedrigere EQ-Index Werte nach 12 Monaten aufwiesen als asymptomatische VHF-Patient:innen (MonDAFIS p ≤ 0,042). Schlussfolgerungen: Neben bekannten Einflussfaktoren ist die HRQOL bei Patient:innen mit ischämischem Schlaganfall/TIA auch mit VHF und potentiell modifizierbaren Faktoren, wie einer OAK-Einnahme und der VHF-Symptomschwere assoziiert. Für den klinischen Alltag könnte das einen Bedarf an besonderer Beachtung dieser Patient:innenkohorte aufzeigen, da sich der klinische Nutzen einer OAK neben der Vermeidung kardiovaskulärer Ereignisse auch in der HRQOL widerspiegelt.Background/Purpose: Atrial fibrillation (AF) causes up to 15-20% of all ischemic strokes. Patients with AF as well as patients with ischemic stroke suffer from reduced health-related quality of life (HRQOL). Furthermore AF-related symptoms may impair HRQOL. However, little is known about HRQOL in patients with ischemic stroke and transient ischemic attack (TIA) with AF. The aim of this thesis is to characterize the association of AF, its related symptoms, and the status of oral anticoagulation (OAC) on HRQOL in patients with ischemic stroke/TIA. Methods: Data of the “Impact of standardized MONitoring for Detection of Atrial Fibrillation in Ischemic Stroke (MonDAFIS)”-trial and “Berlin Atrial Fibrillation Registry”-trial (BVR) were analyzed. Both studies are investigator-initiated, prospective, multicentre trials of the Charité – Universitätsmedizin Berlin. The MonDAFIS trial enrolled 3,470 patients with acute ischemic stroke or TIA without known AF. The BVR trial enrolled 1,080 patients with AF and ischemic stroke or TIA. Data on HRQOL were measured by using the EQ-5D-3L questionnaire, including the EQ-index and the EQ-VAS, at baseline and several follow-ups. Statistical analysis was performed using multivariable linear models adjusting for HRQOL at baseline, sociodemographic factors, stroke severity, further cardiovascular events, comorbidities, AF, type and persistence of OAC, symptom severity of AF (EHRA-score) and study-center. Results: Patients with AF without OAC showed lower HRQOL compared to patients with AF and OAC 12 months after the index stroke/TIA (MonDAFIS: EQ-Index p=0,003; EQ-VAS p=0,042; BVR: EQ-VAS p=0,017). Patients with AF and OAC showed similarly high HRQOL compared to patients without AF and without OAC (MonDAFIS: EQ-Index p=0,349; EQ-VAS p=0,624). Non-persistence to OAC was associated with lower EQ-VAS values 12 months (BVR: p<0,001) and in the course of 36 months (BVR: p<0,001) after ischemic stroke/TIA. Moreover, patients with symptomatic AF had lower EQ-index values than asymptomatic patients after 12 months (MonDAFIS p ≤ 0,042). Conclusions: HRQOL in patients with ischemic stroke or TIA is beside known factors of influence associated with AF and potentially modifiable factors such as symptom severity of AF and secondary prophylaxis by OAC. As a clinically relevant expression of the patients’ perspective, these factors should be considered in clinical routine because OAC intake has in addition to the reduction of recurrent cardiovascular events a statistically significant association with HRQOL

    Conjugando amor e desejo: experiências masculinas do "assumir-se" homossexual

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    Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas. Programa de Pós-graduação Interdisciplinar em Ciências HumanasNesta tese apresento o resultado da pesquisa que desenvolvi no Doutorado Interdisciplinar em Ciências Humanas (DICH/UFSC) sobre homens de camadas médias da cidade de Porto Alegre, capital do Rio Grande do Sul. Todos são pais, tiveram casamentos heterossexuais, viveram experiências de separação de suas esposas e posterior construção de vínculos afetivo-sexuais conjugais com outros homens. Nesse percurso que levou a conjugalidade homoerótica, "assumiram-se homossexuais". Através do método de pesquisa que defini como "etnografia psicanalítica" busquei compreender os sentidos e os significados atribuídos por estes sujeitos aos deslocamentos e às mudanças de um modo de vida afetivo-sexual heterossexual, para um outro estilo de vida, assumidamente homossexual e homoerótico. Analisei nesta tese aspectos relacionados aos significados do casamento heterossexual e da conjugalidade homoerótica na vida destes sujeitos, bem como a relação entre casamento (tanto hetero como homo) e a afirmação de identidade de gênero. Para tanto, investiguei as distâncias e aproximações entre o campo dos afetos, das emoções e suas articulações com a sexualidade, desde perspectivas teóricas oriundas das ciências humanas, das ciências sociais, da psicanálise e dos estudos de gênero. Centrei minhas análises na relação entre afeto e sexualidade na construção do gênero masculino e na vivência concreta e singular dos sujeitos com quem dialoguei no campo. Acrescento a essa análise, a articulação entre gênero masculino e homossexualidade masculina, para compreender os significados do "assumir" a homossexualidade na vida dos entrevistados
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