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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Impulso sexual excessivo, aspectos neuropsicológicos no estado de vigília e pós-estímulo sexual: estudo experimental / Excessive sexual drive, neuropsychological aspects during basal wakefulness and after sexual stimulation: experimental study

Bruna Messina 17 April 2015 (has links)
INTRODUÇÃO: A despeito das graves consequências comportamentais de indivíduos que sofrem de impulso sexual excessivo (ISE), estudos neuropsicológicos são incipientes e trazem resultados controversos. OBJETIVOS: Por meio de um estudo experimental com sujeitos impulsivos sexuais (pacientes) e não impulsivos sexuais (controles) objetivou-se comparar: a tomada de decisão e a flexibilidade cognitiva no estado basal de vigília (tempo \"0\"); a tomada de decisão e flexibilidade cognitiva no tempo \"0\" e pós-estímulo sexual visual (tempo \"1\") em cada grupo (pacientes e controles) e entre os grupos. MÉTODO: O estudo foi desenvolvido no Ambulatório de ISE do Instituto de Psiquiatria (IPq) do HC-FMUSP. A amostra foi constituída por 30 pacientes e 30 controles recrutados através de divulgação na mídia. Homens, brasileiros, com 18 anos ou mais, que preencheram os critérios diagnósticos para ISE (CID-10 - F 52.7) e os critérios de Goodman para dependência de sexo foram incluídos como pacientes; enquanto participantes assintomáticos e que não preencheram os critérios acima foram incluídos como controles. A investigação neuropsicológica da flexibilidade cognitiva se deu por meio da aplicação Wisconsin Card Sort Test (WCST), enquanto a avaliação da tomada de decisão se deu pela aplicação do Iowa Gambling Task (IGT) no tempo \"0\" e tempo \"1\" (após visualização de vídeo erótico por 20 minutos), respeitando um intervalo mínimo de seis meses entre os tempos. Em ambos os tempos foi aplicada a Escala de Compulsividade Sexual, e no tempo \"1\" foi aplicado o Inventário do Desejo e da Excitação Sexual. RESULTADOS: No estado basal, os pacientes apresentaram maior quantidade de respostas corretas, em relação aos controles, no teste que investiga flexibilidade cognitiva (p = 0,01). Quando comparamos o desempenho de ambos os grupos com eles mesmos entre os tempos, observamos que os controles apresentaram melhor desempenho inicial (Bloco 1) na tomada de decisão (p = 0,01), bem como apresentaram mais acertos no teste que avalia flexibilidade cognitiva (p = 0,01) no tempo \"1\". O mesmo não foi observado em relação aos pacientes. Quando comparamos as médias da diferença (tempo \"1\" - tempo \"0\"), entre os grupos, observamos também melhor desempenho dos controles em relação à quantidade de acertos (p = 0,02). CONCLUSÕES: Desde onde sabemos, este é o primeiro estudo avaliando funções executivas em impulsivos sexuais, após exposição a estímulo visual sexual. Quanto à avaliação no estado basal, os pacientes apresentaram melhores resultados na flexibilidade cognitiva, contrariando a hipótese inicial. Controles apresentaram melhores desempenhos na flexibilidade cognitiva e tomada de decisão inicial após exposição ao estímulo visual sexual, quando comparados com os resultados no estado basal. Na análise da diferença de desempenho pós-estímulo visual sexual comparado com o estado basal, entre os grupos, os controles novamente apresentaram melhor desempenho cognitivo. Tais resultados indicam escolhas iniciais menos impulsivas, e melhor flexibilidade cognitiva, após exposição ao estímulo erótico, pelos controles, sugerindo dificuldades de modulação inicial do comportamento, bem como de funções cognitivas, pelos pacientes, diante do estímulo sexual, apoiando nossas hipóteses / INTRODUCTION: Despite the serious behavioral consequences of individuals suffering from excessive sexual drive (ESD), neuropsychological studies are incipient and bring controversial results. OBJECTIVES: Through an experimental study of sexually impulsive subjects (patients) and non-sexually impulsive (control group) our aim was to compare: decision making and cognitive flexibility during basal wakefulness (Time \"0\"); decision making and cognitive flexibility at time \"0\" and after visual sexual stimulation (time \"1\") in each group (patients and control group) and among groups. METHOD: The study was developed at the ESD Clinic of the Psychiatry Institute (IPq), HC-FMUSP. The sample consisted of 30 patients and 30 people in the control group recruited through media coverage. Brazilian men, 18 years and older who met the diagnostic criteria for ISE (ICD - 10 - 52.7 F) and the Goodman criteria for addiction to sex were included as patients; while asymptomatic participants and that did not meet the above criteria were included in the control group. The neuropsychological research of the cognitive flexibility was made by applying the Wisconsin Card Sort Test (WCST), while the evaluation of the decision-making was made through the application of the Iowa Gambling Task (IGT) at time \"0\" and time \"1\" (after viewing an erotic video for 20 minutes), subject to a minimum interval of six months between times. In both times, the Sexual Compulsivity Scale was applied and to time \"1\", we applied the Sexual Arousal and Desire Inventory. RESULTS: During basal wakefulness patients presented a higher number of correct responses compared to the control group, in the test that investigates cognitive flexibility (p = 0.01). When comparing the performance of both groups to each other in between times, we found that the control group had a better initial performance (Block 1) in decision making (p = 0.01) as well as provided more correct answers in the test that evaluates cognitive flexibility (p = 0.01) at time \"1\". The same was not observed in the patients group. When comparing the average of the difference (time \"1\" - time \"0\") between the groups, we noted a better performance in the control group in what concerns the amount of correct responses (p = 0.02). CONCLUSION: As far as we know, this is the first study assessing executive functions in sexual impulsive, after exposure to sexual visual stimuli. As for the evaluation at basal wakefulness, patients presented better results regarding cognitive flexibility, opposite to the initial hypothesis. The control group presented a better performance concerning cognitive flexibility and initial decision making after exposure to sexual visual stimuli, when compared with results during basal wakefulness. When analyzing the performance difference after visual sexual stimulation compared with basal wakefulness in the two groups, the control group, once again, showed better cognitive performance. Such results indicate less impulsive initial choices and better cognitive flexibility after exposure to erotic stimulation in the control group, suggesting difficulties in the initial modulation of behavior, as well ass of cognitive functions, by patients before sexual stimulation, supporting our hypothesis
62

Contrôle optimal stochastique des processus de Markov déterministes par morceaux et application à l’optimisation de maintenance / Stochastic optimal control for piecewise deterministic Markov processes and application to maintenance optimization

Geeraert, Alizée 06 June 2017 (has links)
On s’intéresse au problème de contrôle impulsionnel à horizon infini avec facteur d’oubli pour les processus de Markov déterministes par morceaux (PDMP). Dans un premier temps, on modélise l’évolution d’un système opto-électronique par des PDMP. Afin d’optimiser la maintenance du système, on met en place un problème de contrôle impulsionnel tenant compte à la fois du coût de maintenance et du coût lié à l’indisponibilité du matériel auprès du client.On applique ensuite une méthode d’approximation numérique de la fonction valeur associée au problème, faisant intervenir la quantification de PDMP. On discute alors de l’influence des paramètres sur le résultat obtenu. Dans un second temps, on prolonge l’étude théorique du problème de contrôle impulsionnel en construisant de manière explicite une famille de stratégies є-optimales. Cette construction se base sur l’itération d’un opérateur dit de simple-saut-ou-intervention associé au PDMP, dont l’idée repose sur le procédé utilisé par U.S. Gugerli pour la construction de temps d’arrêt є-optimaux. Néanmoins, déterminer la meilleure position après chaque intervention complique significativement la construction de telles stratégies et nécessite l’introduction d’un nouvel opérateur. L’originalité de la construction de stratégies є-optimales présentée ici est d’être explicite, au sens où elle ne nécessite pas la résolution préalable de problèmes complexes. / We are interested in a discounted impulse control problem with infinite horizon forpiecewise deterministic Markov processes (PDMPs). In the first part, we model the evolutionof an optronic system by PDMPs. To optimize the maintenance of this equipment, we study animpulse control problem where both maintenance costs and the unavailability cost for the clientare considered. We next apply a numerical method for the approximation of the value function associated with the impulse control problem, which relies on quantization of PDMPs. The influence of the parameters on the numerical results is discussed. In the second part, we extendthe theoretical study of the impulse control problem by explicitly building a family of є-optimalstrategies. This approach is based on the iteration of a single-jump-or-intervention operator associatedto the PDMP and relies on the theory for optimal stopping of a piecewise-deterministic Markov process by U.S. Gugerli. In the present situation, the main difficulty consists in approximating the best position after the interventions, which is done by introducing a new operator.The originality of the proposed approach is the construction of є-optimal strategies that areexplicit, since they do not require preliminary resolutions of complex problems.
63

Design of a conveyance device based on a digital actuators array and structured plate / Conception d’un système de déplacement basé sur un réseau d’actionneurs numériques et d’un plateau structuré

Xu, Jing 17 May 2016 (has links)
Les actionneurs numériques sont composés d'une partie mobile pouvant se déplacer entre des positions discrètes précisément connues et répétables. Contrairement aux actionneurs analogiques classiques, le pilotage d'actionneurs numériques est réalisé très simplement à l'aide d'une commande impulsionnelle et en boucle ouverte. De ce fait, aucun capteur n'est nécessaire ce qui facilite leur intégration dans des systèmes hôtes. La qualité de fabrication de ces actionneurs est cependant primordiale car une éventuelle erreur ne peut pas être corrigée par la commande. Les travaux présentés porteront sur un réseau composé de 25 actionneurs numériques disposant chacun de quatre positions discrètes avec un plateau glissant. L'application visée est la réalisation d'un système de convoyage planaire dans laquelle les actionneurs permettent de déplacer un plateau selon les deux directions du plan. Les résultats de la simulation sont comparés avec les résultats expérimentaux. En suite, un réseau composé de quatre actionneurs numériques avec un plateau structuré est étudié. La conception du réseau d'actionneurs puis la stratégie de pilotage permettant de réaliser le déplacement du plateau structuré seront tout d'abord présentées. Un prototype de réseau d'actionneurs et des résultats expérimentaux de convoyage selon une direction sera ensuite détaillé et l'influence d'erreurs de fabrication sur le fonctionnement du réseau sera mise en évidence. / The open loop control is widely used by the digital systems to facilitate the integration in complex systems because no sensor is needed. The research is based on digital actuator which is composed of a mobile part and a fixed part. The actuator moves between the discrete positions. The discrete displacement consumes low energy, which is controlled by impulse only needed to switch the actuator between the discrete positions. However, the stroke of digital actuator is fixed at the manufacturing. So the digital actuators array is used to obtain variable strokes. A digital actuators array used here with a structured plate is applied as a 2D planar conveyance. Firstly, an actuators array composed of 25 elementary actuators with a flat plate is studied. The simulated results are compared with the experimental results. Then another actuators array composed of four elementary actuators with a structured plate is designed. The design and the plate displacement are firstly presented. Then the prototype of the conveyance is fabricated with laser cutting machine and 3D printer. The experiment is then tested in one direction to study the plate displacement. The open loop control is simple by using current impulse. The operation can be well functioned which is observed during the experiment. The experimental results are compared with the theoretical results.
64

Conduct disorder among girls: violent behaviour, suicidality and comorbidity:a study of adolescent inpatients in Northern Finland

Ilomäki, E. (Essi) 02 October 2012 (has links)
Abstract Conduct disorder (CD) among girls is a common but seldom studied psychiatric disorder. The aim of this study was to examine risk factors for CD, the factor structure of CD symptoms, suicidal behaviour, comorbid disorders and nicotine dependence of adolescent girls with CD in an inpatient sample in Northern Finland. The study subjects were 508 12- to 17-year-old inpatients treated in an acute psychiatric ward, Unit 70, at Oulu University Hospital between April 2001 and March 2006. These adolescents were interviewed using the Schedule for Affective Disorder and Schizophrenia for School-Age Children Present and Lifetime (K-SADS-PL) to obtain psychiatric diagnoses according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). In addition, the European Addiction Severity Index (EuropASI) was used to obtain information on somatic health, family situation and delinquency. From the data collected, 63 girls and 92 boys fulfilled the criteria for current DSM-IV-diagnosed conduct disorder. It was observed that, although the number of symptoms and severity of CD was lower among girls compared to boys, the level of functioning was lowered to the same degree. Physical abuse increased the risk for violent CD, and living apart from at least one biological parent increased the risk for both violent and non-violent CD among girls. The results of this study also suggest a gender difference in the factor structure and developmental model of CD. Alcohol dependence increased the risk for suicide attempt and self-mutilation almost fourfold among girls with CD. Girls with CD had more comorbid affective and anxiety disorders than boys. Girls with CD also had more self-reported allergies. Finally, the number of CD symptoms was positively correlated with the level of nicotine dependence (ND) among both girls and boys, and a gender difference was found in the correlation between symptom subscales and the level of ND. The findings suggest that gender differences exist in conduct disorder. Special attention should be paid to the prevention, identification and treatment of CD among girls. It seems that, among girls with CD, the well-being of primary family is important in prevention. Alcohol dependence and depression in girls with CD should be treated with special care. DSM-IV might not always be sensitive enough to diagnose CD among girls, and this should be considered when behavioural symptoms are evaluated in girls. / Tiivistelmä Tyttöjen käytöshäiriö on vähän tutkittu mutta yleinen psykiatrinen häiriö. Tässä tutkimuksessa analysoitiin tyttöjen käytöshäiriön riskitekijöitä, oireiden faktorirakennetta, käytöshäiriöisten itsetuhoisuutta, samanaikaista psykiatrista ja somaattista sairastavuutta sekä nikotiiniriippuvuutta psykiatrisessa osastohoidossa olleiden alaikäisten nuorten keskuudessa. Tutkimusaineistoon kuului 508 12–17-vuotiasta nuorta, jotka olivat hoidossa psykiatrisella akuuttihoito-osastolla Oulun yliopistollisessa sairaalassa 1.4.2001–31.3.2006 välisenä aikana. Nuoret haasteteltiin käyttämällä puolistrukturoitua Schedule for Affective Disorder and Schizophrenia for School-Age Children Present and Lifetime (K-SADS-PL) -haastattelua, jonka avulla määritettiin nuorten psykiatriset diagnoosit Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) -diagnoosiluokituksen mukaisesti. Lisäksi potilaat haastateltiin European Addiction Severity Index (EuropASI) -haastattelulla, josta saatiin tietoa fyysisestä terveydentilasta, perhetilanteesta ja rikollisuudesta. Aineiston nuorista 63 tyttöä ja 92 poikaa täyttivät käytöshäiriön kriteerit. Tämä tutkimus osoitti, että vaikka nykyisten DSM-IV-kriteerien perusteella tytöillä käytöshäiriön vaikeusaste oli aiempien tutkimusten tapaan poikia alhaisempi ja oireiden määrä vähäisempi, oli tyttöjen toimintakyky silti yhtä huono kuin poikien. Fyysinen perheväkivalta lisäsi tyttöjen riskiä väkivaltaiseen käytöshäiriöön ja asuminen erossa vähintään yhdestä biologisesta vanhemmasta lisäsi riskiä sekä väkivaltaiseen että ei-väkivaltaiseen käytöshäiriöön. Käytöshäiriöoireiden faktorianalyysi osoitti, että tytöillä ja pojilla oli eroa oireiden faktorirakenteessa eikä tyttöjen oireiden jako selkeästi noudattanut Loeberin esittämää polkumallia. Alkoholiriippuvuus lisäsi käytöshäiriöisillä tytöillä riskiä itsemurhan yrittämiseen ja itsensä vahingoittamiseen lähes 4-kertaiseksi. Käytöshäiriöisillä tytöillä oli poikia enemmän mieliala- ja ahdistushäiriöitä samanaikaisina psykiatrisina häiriöinä. Somaattisista häiriöistä käytöshäiriöiset tytöt raportoivat poikia enemmän allergioita. Käytöshäiriön oireiden määrä oli yhteydessä sekä tytöillä että pojilla nikotiiniriippuvuuden voimakkuuteen. Tyttöjen ja poikien välillä oli eroa nikotiiniriippuvuuteen korreloivissa oireryhmissä. Tämän tutkimuksen tulosten perusteella tyttöjen ja poikien käytöshäiriöllä on eroavaisuuksia. Tyttöjen käytöshäiriön ennaltaehkäisyyn, tunnistamiseen ja hoitoon tulee kiinnittää erityistä huomiota. Primaariperheen hyvinvointi näyttäisi olevan tärkeää ennaltaehkäisyssä. Käytöshäiriöisen tytön hoidossa tulee kiinnittää erityinen huomio alkoholin käyttöön sekä depression hoitoon itsetuhoisuuden ehkäisemiseksi. DSM-IV ei ehkä nykyisellään ole riittävän herkkä työkalu tyttöjen käytöshäiriön diagnosoimiseksi, ja tähän tulisi kiinnittää huomiota kun käyttäytymisellään oireilevia tyttöjä hoidetaan.
65

Diagnostik und störungsspezifische Therapie bei Sexualdelinquenten mit psychischen Störungen

Hoyer, Jürgen, Borchard, Bernd, Kunst, Heike January 2000 (has links)
Hintergrund: Systematische Darstellungen zur Diagnostik und Verhaltenstherapie von sexuellen Gewalttätern mit psychischen Störungen fehlen im deutschen Sprachraum fast völlig. In der vorliegenden Arbeit werden deshalb für diese kleine, aber besonders gefährliche Tätergruppe die auf der Basis des DSM IV hauptsächlich relevanten Diagnosen (Paraphilie und Störung der Impulskontrolle) und für diese Störungen geeignete Behandlungsmethoden vorgestellt. Methoden: Merkmale, die Paraphile und Impulskontrollgestörte im Hinblick auf Lerngeschichte, sexuelle Präferenz und tatauslösende Bedingungen differenzieren, werden dabei hervorgehoben. Weiterhin wird eine erste Validierungsstudie vorgestellt, in der untersucht wurde, inwieweit sich beide Störungsgruppen hinsichtlich Impulsivität, sozialer Angst, Konfliktvermeidung und dysfunktionaler Selbstaufmerksamkeit unterscheiden. Ergebnisse: Die Ergebnisse verdeutlichen, dass die vorgeschlagene Kategorisierung valide ist und dass sich Paraphile und Impulskontrollgestörte psychologisch bedeutsam voneinander differenzieren lassen. Schlussfolgerungen: Auf dieser Basis lassen sich Aussagen über störungsspezifisch relevante Behandlungselemente ableiten. Unterschiedliche Vorgehensweisen bei Paraphilen bzw. Impulskontrollgestörten werden für folgende Bereiche skizziert: Aufbau einer therapeutischen Beziehung, Änderung der sexuellen Präferenzen, Training sozialer Fertigkeiten und der Konfliktbewältigung, Modifikation dysfunktionaler Kognitionen und Rückfallprävention. / Background: Systematic work regarding the diagnostics and behavior therapy of violent sex offenders with mental disorders is mostly lacking in German publications. Therefore, this study presents the diagnoses which are mainly relevant for this small but particularly dangerous group of offenders on the basis of DSM IV (paraphilia and impulse control disorders) and describes specifically indicated interventions. Methods: Characteristic features are emphasized which differentiate paraphiliacs and offenders with an impulse control disorder with regard to learning history, sexual preferences, and the stimulus conditions which triggered the offense. Further, a validation study is presented which examined the differences between both disorders concerning impulsivity, social anxiety, avoidance of interpersonal conflicts, and dysfunctional self-consciousness. Results: Results showed that the proposed categorization is valid and that paraphiliacs and offenders with an impulse control disorder can be psychologically useful differentiated. Conclusions: In this framework, first conclusions can be drawn regarding the treatment elements which are considered to be relevant for disorder-specific therapy. Different procedures for the treatment of paraphiliacs and offenders with an impulse control disorder are described for the following areas: establishment of a therapeutic relationship, modification of sexual preferences, training of social and coping skills, conflict management, modification of cognitive distortions, and relapse prevention. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
66

Mécanismes physiopathologiques des comportements impulsifs associés à la maladie de Parkinson : approches expérimentales chez le rat / Pathophysiological mechanisms of Parkinson's disease related impulsive behaviors : preclinical approach in the rat

Magnard, Robin 15 February 2019 (has links)
Au-delà des symptômes moteurs, la maladie de Parkinson (MP) est également caractérisée par une myriade de symptômes neuropsychiatriques allant de l’apathie et la dépression aux troubles du contrôle des impulsions (TCI). Les TCI représentent un groupe d’addictions comportementales incluant le jeu pathologique, l’hypersexualité et les achats faits de manière compulsive. Observés chez 10 à 14 % des patients parkinsoniens sous traitement dopaminergique, ils affectent fortement leur qualité de vie. L’impulsivité cognitive reflétant notamment l’incapacité à tolérer les délais de renforcements, est au cœur des TCI. En effet, différentes études suggèrent que cette impulsivité serait exacerbée dans la MP et sous traitements dopaminergiques. Cependant, les mécanismes sous-tendant les TCI dans la MP demeurent méconnus, et la contribution respective de la lésion, du traitement dopaminergique, et de certains facteurs de vulnérabilité reste à déterminer. De plus, l’impulsivité d’attente, une autre forme de déficit d’inhibition qui peut conduire au développement de comportements compulsifs, a été peu étudiée dans le cadre des TCI.L’objectif de ce projet de thèse a été d’évaluer l’influence d’une dénervation dopaminergique de la voie nigrostriée, avec ou sans adjonction d’agoniste dopaminergique, sur le développement d’impulsivité. Pour cela, nous avons utilisé un modèle lésionnel des troubles non-moteurs de la MP. Ces rats ont reçu une injection bilatérale de neurotoxine 6-OHDA dans la SNc, afin d’induire une dénervation sélective, bilatérale et partielle du striatum dorsal. Ils ont ensuite été traités avec du pramipexole, un agoniste des récepteurs D2/3, connu pour favoriser le développement de TCI chez les patients parkinsoniens. Les tâches d’intolérance au délai et de réaction en série à 5 choix (5-CSRTT) ont été utilisées pour évaluer respectivement l’impulsivité cognitive et l’impulsivité d’attente. Dans le premier paradigme, les rats doivent appuyer sur un levier pour choisir entre une petite récompense immédiate, ou une plus grosse récompense, avec un un délai. Dans le second paradigme, ils doivent inhiber l’émission d’une réponse motrice jusqu’à l’apparition d’un stimulus lumineux. Le traitement chronique au pramipexole augmente considérablement les choix impulsifs effectués dans la tâche d’intolérance au délai, mais seulement chez les rats non lésés. En effet, la lésion dopaminergique seule ou avec le traitement ne favorise pas les comportements impulsifs. Dans la tâche de 5-CSRTT, le pramipexole semble également promouvoir l’émission de réponses prématurées (effet pro-impulsif), lorsque l’intervalle inter-essais est constant. Cependant, lorsque cet intervalle augmente, le pramipexole provoque à l’inverse une diminution des réponses prématurées (effet anti-impulsif). Cette modulation d’impulsivité étant seulement observée chez les rats hautement impulsifs, ceci suggère qu’un endophénotype impulsif puisse être un facteur de vulnérabilité à l’effet iatrogène du pramipexole.A l’échelle neuronale, ce traitement favorise la surexpression des ARNm codants pour les récepteurs dopaminergiques D2 dans le striatum et y modifie la connectivité glutamatergique telle qu’observée en microscopie électronique. De plus, nous avons observé une suractivation de la voie mTORC1 dans le noyau accumbens, comme déjà constaté dans les processus addictifs. Afin d’apporter un lien causal à cette étude, nous avons bloqué l’activité de la voie mTORC1 par un inhibiteur spécifique, la rapamycine, chez des rats traités au pramipexole. Etonnamment, cette combinaison accentue fortement l’intolérance au délai, alors que la rapamycine seule ne provoque aucun effet notable. Ceci pourrait s’expliquer par une cinétique d’activation et d’inhibition complexe de cette voie. L’ensemble de ces résultats suggère que l’impulsivité observée dans la MP serait causée par une action iatrogène du pramipexole via une activation anormale de la voie mTORC1 dans le noyau accumbens. / Beyond motor symptoms, Parkinson’s disease (PD) is also characterized by a plethora of neuropsychiatric deficits, ranging from apathy and depression to Impulse control disorders (ICDs). ICDs represent a complex group of behavioral addictions including gambling disorders, hypersexuality and compulsive shopping, displayed by 10 to 14% of PD patients under dopamine replacement therapies, whose quality of life is greatly diminished. Importantly, cognitive impulsivity reflecting in particular, an inability to tolerate delays to reinforcements, appears as a core symptom of ICDs. Indeed, recent evidence suggested that this kind of impulsivity would be exacerbated in PD and under treatment by dopaminergic D2/3 receptor agonists. However, the mechanisms underlying ICDs in PD remain unknown and the respective contribution of dopamine lesion and treatment, combined with factors of vulnerability, remain to be determined. Moreover, waiting impulsivity, another form of behavioral inhibition which may lead to compulsive behaviors, has been poorly investigated in the framework of ICDs.In this thesis project, using a lesional rodent model of non-motor symptoms of PD, we addressed the question of whether denervation of the dopaminergic nigrostriatal system would promote the development of impulsivity when combined with dopamine agonist treatments. Rats were bilaterally injected in the SNc with the neurotoxin 6-OHDA to induce selective and partial denervation of the dorsal striatum. We then treated them with the dopamine D2/3 receptor agonist, pramipexole, a medication known to favor the development of ICDs in PD patients. Two different tasks were used to measure cognitive and motor impulsivity: the delay discounting task (DDT) and the 5-choice serial reaction time task (5-CSRTT) respectively. In the former, rats have to press a lever and choose between a smaller, but immediate reward and a larger, but delayed reward. For the latter, they have to wait for a stimulus light to come on. In the DDT, chronic administration of pramipexole treatment only increased impulsive choices in non-lesioned rats. Indeed, the dopaminergic lesion by itself, or in adjunction with the treatment, did not increase impulsivity. In the 5-CSRTT, pramipexole progressively increased premature responses, reflecting a pro-impulsive effect when the inter-trial interval is constant. However, when the interval was increased, pramipexole reduced the premature responses, exhibiting an anti-impulsive effect. Interestingly, this modulation of motor impulsivity was only observed in rats with a high level of impulsivity, suggesting that an impulsive endophenotype might be an important factor of vulnerability to the iatrogenic effects of pramipexole.The effect of this treatment was then investigated at a cellular level. It promotes overexpression of the dopamine D2 receptor mRNA within the striatum, and seems to alter glutamatergic synaptic connectivity suggested by electron microscopy. Moreover, we showed that the mammalian target of rapamycin complex 1 (mTORC1) pathway is lastingly over-activated in the nucleus accumbens, as already observed in drug addictions. In an attempt to make a causal link between this pathway and the behavioral changes, we treated rats with pramipexole and rapamycine, a specific inhibitor of this pathway. Surprisingly, this combination accentuated impulsivity even more, whereas rapamycine by itself did not promote impulsivity. This effect may be explained by the complexity of the kinetics of activation and inhibition of mTORC1 pathway.Taken together, these results suggest that impulsivity in PD may be triggered by an iatrogenic effect of the dopaminergic pramipexole treatment through an abnormal activation of the mTORC1 pathway within the nucleus accumbens.
67

The relationship between trait impulsivity and alcohol related attentional biases

Coskunpinar, Ayca 08 May 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Harmful alcohol use is a global concern, which has made research in this area a prime public health interest. Previous research has identified alcohol-related attentional biases (Cox et al., 2002, 2007; Marissen et al., 2006; Streeter et al., 2008) and impulsivity (see Acton, 2003; Dick et al., 2010; Mulder, 2002) as two important predictors that affect alcohol use, seeking, and relapse (Cox et al., 2002; Robbins & Ehrman, 2004). Recent review of the literature has also revealed that there is a significant relationship between these two constructs (Coskunpinar & Cyders, 2013). The current study used college undergraduate social drinkers (at least 3 drinks per week) (n = 42, mean age = 23.27 (SD = 5.21), female: 69.2%) to examine the relationship between specific trait impulsivity facets and alcohol-related attentional biases and to examine how this relationship is affected by measurement type (eye movement, reaction time measures), attentional bias constructs (initial orientation, delayed disengagement), and environmental cues (specifically mood and alcohol olfactory cues). Participants had alcohol-related attentional bias as measured by reaction time (areas of interest: p < .05) and eye-movement data (areas of interest: p < .05), which was not affected by mood, odor, or urgency.
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Os aspectos psicopatológicos e fenomenológicos do transtorno de escoriação / Psychopathological and phenomenological features associated with excoriation disorder

Oliveira, Elen Cristina Batista de 08 November 2018 (has links)
Introdução: O Transtorno de Escoriação (TE) é caracterizado pelo comportamento repetitivo e excessivo de escoriar a pele saudável, resultando em dano tecidual e significativo sofrimento, associado a ânsia incontrolável e falha em controlar tal comportamento repetitivo. Atualmente o TE é classificado na seção de transtornos relacionados aos Transtornos Obsessivo-compulsivos (TOC) da 5ª edição do Manual de Diagnóstico e Estatística de Transtornos Mentais (DSM). No entanto, ainda existem debates a respeito da sua classificação, se o mesmo está relacionado a transtornos relacionados ao TOC, ou se é melhor conceituado como uma dependência comportamental. Objetivos: O presente estudo comparou um grupo de indivíduos com TE com dois paradigmas dos transtornos obsessivo-compulsivos, i.e., TOC, e dos transtornos impulsivo-aditivos, i.e., Transtorno do Jogo (TJ), analisando suas características sociodemográficas, clínicas, categorias diagnósticas, perfil de comorbidades, sintomas obsessivo-compulsivos, traços impulsivos e atributos de personalidade. O objetivo de tal comparação foi avaliar se o TE estaria mais relacionado aos transtornos relacionados ao TOC ou ao TJ. Métodos: Participaram do estudo 121 pacientes, que procuraram o tratamento no Instituto de Psiquiatria (IPq) do Hospital das Clínicas da Faculdade de Medicina da Universidade São Paulo (HCFMUSP), Brasil. Do total de 121 participantes, 40 foram diagnosticados com TE, 41 com TOC e 40 com TJ. Foram utilizadas entrevistas clínicas estruturadas para diagnosticar e comparar os três grupos na sobreposição diagnóstica e nas comorbidades psiquiátricas atuais, e escalas de autopreenchimento padronizadas para avaliar os sintomas dimensionais e comparar os três grupos em análise dimensional. Resultados: O grupo TE apresentou maior preponderância de mulheres, mais jovens e com maior instrução acadêmica. Na análise categorial TE se aproximou, significativamente, mais de TOC (n = 14) do que de TJ (n = 3), se sobrepondo ao primeiro. Os grupos TE e TOC também foram mais propensos a apresentar outros Comportamentos Repetitivos Focados no Corpo (CRFC) e transtornos ansiosos em geral. A presença de CRFC diferenciou TE de TJ, por outro lado, TE se diferenciou de TOC pela presença de comportamentos aditivos. A análise dimensional demonstrou que TE se apresenta como um modelo híbrido de obsessividade-compulsividade e impulsividade. Finalmente, a análise de correlação mostrou que os escores de obsessividade-compulsividade e impulsividade não foram correlacionados à gravidade dos sintomas de escoriação da pele. Discussão: Os dados da análise categorial apoiam a classificação de TE como um transtorno correlato ao TOC. Já os achados das análises dimensionais sugerem que uma apresentação psicopatológica híbrida de TE, contendo tanto elementos obsessivo-compulsivos, como com traços impulsivos. No entanto, nenhum desses aspectos foram correlacionados à gravidade dos sintomas de escoriação no grupo TE, sugerindo que o comportamento de escoriação da pele é independente desses fatores nestes indivíduos. O conjunto de tal apresentação sucinta a alocação de TE junto ao grupo dos chamados CRFC. Conclusão: TE apresenta um perfil demográfico e clínico próprios. TE e TOC compartilham mais similaridades no perfil de comorbidades psiquiátricas do que TJ, a maioria baseada nos transtornos ansiosos. Por outro lado, TE se diferencia de TOC, por uma associação mais frequente com os transtornos aditivos. TE apresentou níveis intermediários de compulsividade e impulsividade na abordagem dimensional. O comportamento de escoriação não mostrou correlação relevante com as medidas dimensionais de compulsividade nem impulsividade. TE, de uma forma geral, teve uma associação robusta com os outros CRFC, diferenciando-se de TOC e de TJ. TE poderia ser classificado em uma sessão à parte juntamente com outros CRFC / Introduction: Excoriation Disorder (ED) is characterized by repetitive and excessive picking on healthy skin, resulting in significant skin damage and psychological distress associated with uncontrollable urge and failure to control this repetitive behavior. ED is currently classified under the Obsessive-compulsive and Related Disorders (OCRD) section of the Diagnostic and Statistics Manual of Mental Disorders - 5th edition. Nevertheless, there is still no consensus whether ED is more closely related to OCRDs or it would be better conceptualized as a behavioral addiction. Objectives: Compare ED patients with two paradigms of obsessive-compulsive disorders (OCD) and impulsive-addictive disorders (gambling disorder), analyzing their sociodemographic and clinical characteristics, diagnostic categories, comorbidity profile, obsessive-compulsive symptoms, impulsive traits, and personality features. The purpose of this comparison was to assess whether ED was more related to OCD-related disorders (OCDRD) or to behavioral addictions, e.g., Gambling Disorder (GD). Methods: Study participants were 121 patients seeking treatment at Instituto de Psiquiatria (IPq), Hospital das Clinicas da Faculdade de Medicina da Universidade Sao Paulo (HCFMUSP), Sao Paulo, Brasil. Of the 121 participants, 40 were diagnosed with ED, 41 with OCD, and 40 with GD. Structured clinical interviews were used to diagnose and compare the three groups in diagnostic overlap and current psychiatric-comorbidities, and standardized self-reports were used to evaluate the dimensional variables. Results: Participants in the ED group were more likely to be women, young, and with higher levels of education compared with those of the other groups. In the categorical analysis, ED was more significantly approached to OCD (n=14) than to GD (n=3), overlapping the first. In general, ED and OCD were also more likely to exhibit other body-focused repetitive behaviors (BFRB) and anxiety disorders. The presence of BFRB differentiated ED from GD. In contrast, ED differed from OCD by the presence of addictive behaviors. The dimensional analysis found that ED is a hybrid model of obsessive-compulsivity and impulsivity. Discussion: Categorical analysis supports the classification of ED as OCDRD; however, ED presented differences that may share underlying characteristics with OCD (e.g., compulsivity) and behavioral addiction (e.g., impulsivity). Dimensional analysis suggests a heterogeneous psychopathological in ED with both obsessive-compulsive and impulsive features. Correlation analysis shows that obsessive-compulsivity and impulsivity scores were not correlated to skin excoriation severity symptoms. The overall viewpoints to the allocation of ED points to its own diagnostic category, that is, Body-focused Repetitive Behaviors (BFRB). Conclusion: ED shows a peculiar demographic and clinical profile. ED and OCD share more similarities in the profile of psychiatric comorbidities than GD, mostly based on anxiety disorders. In contrast, ED differs from OCD by a more frequent association with addictive disorders. ED presented intermediate levels of compulsivity and impulsivity between OCD and GD in the dimensional approach. The excoriation behavior showed no relevant correlation with dimensional measures of compulsivity or impulsivity
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Os aspectos psicopatológicos e fenomenológicos do transtorno de escoriação / Psychopathological and phenomenological features associated with excoriation disorder

Elen Cristina Batista de Oliveira 08 November 2018 (has links)
Introdução: O Transtorno de Escoriação (TE) é caracterizado pelo comportamento repetitivo e excessivo de escoriar a pele saudável, resultando em dano tecidual e significativo sofrimento, associado a ânsia incontrolável e falha em controlar tal comportamento repetitivo. Atualmente o TE é classificado na seção de transtornos relacionados aos Transtornos Obsessivo-compulsivos (TOC) da 5ª edição do Manual de Diagnóstico e Estatística de Transtornos Mentais (DSM). No entanto, ainda existem debates a respeito da sua classificação, se o mesmo está relacionado a transtornos relacionados ao TOC, ou se é melhor conceituado como uma dependência comportamental. Objetivos: O presente estudo comparou um grupo de indivíduos com TE com dois paradigmas dos transtornos obsessivo-compulsivos, i.e., TOC, e dos transtornos impulsivo-aditivos, i.e., Transtorno do Jogo (TJ), analisando suas características sociodemográficas, clínicas, categorias diagnósticas, perfil de comorbidades, sintomas obsessivo-compulsivos, traços impulsivos e atributos de personalidade. O objetivo de tal comparação foi avaliar se o TE estaria mais relacionado aos transtornos relacionados ao TOC ou ao TJ. Métodos: Participaram do estudo 121 pacientes, que procuraram o tratamento no Instituto de Psiquiatria (IPq) do Hospital das Clínicas da Faculdade de Medicina da Universidade São Paulo (HCFMUSP), Brasil. Do total de 121 participantes, 40 foram diagnosticados com TE, 41 com TOC e 40 com TJ. Foram utilizadas entrevistas clínicas estruturadas para diagnosticar e comparar os três grupos na sobreposição diagnóstica e nas comorbidades psiquiátricas atuais, e escalas de autopreenchimento padronizadas para avaliar os sintomas dimensionais e comparar os três grupos em análise dimensional. Resultados: O grupo TE apresentou maior preponderância de mulheres, mais jovens e com maior instrução acadêmica. Na análise categorial TE se aproximou, significativamente, mais de TOC (n = 14) do que de TJ (n = 3), se sobrepondo ao primeiro. Os grupos TE e TOC também foram mais propensos a apresentar outros Comportamentos Repetitivos Focados no Corpo (CRFC) e transtornos ansiosos em geral. A presença de CRFC diferenciou TE de TJ, por outro lado, TE se diferenciou de TOC pela presença de comportamentos aditivos. A análise dimensional demonstrou que TE se apresenta como um modelo híbrido de obsessividade-compulsividade e impulsividade. Finalmente, a análise de correlação mostrou que os escores de obsessividade-compulsividade e impulsividade não foram correlacionados à gravidade dos sintomas de escoriação da pele. Discussão: Os dados da análise categorial apoiam a classificação de TE como um transtorno correlato ao TOC. Já os achados das análises dimensionais sugerem que uma apresentação psicopatológica híbrida de TE, contendo tanto elementos obsessivo-compulsivos, como com traços impulsivos. No entanto, nenhum desses aspectos foram correlacionados à gravidade dos sintomas de escoriação no grupo TE, sugerindo que o comportamento de escoriação da pele é independente desses fatores nestes indivíduos. O conjunto de tal apresentação sucinta a alocação de TE junto ao grupo dos chamados CRFC. Conclusão: TE apresenta um perfil demográfico e clínico próprios. TE e TOC compartilham mais similaridades no perfil de comorbidades psiquiátricas do que TJ, a maioria baseada nos transtornos ansiosos. Por outro lado, TE se diferencia de TOC, por uma associação mais frequente com os transtornos aditivos. TE apresentou níveis intermediários de compulsividade e impulsividade na abordagem dimensional. O comportamento de escoriação não mostrou correlação relevante com as medidas dimensionais de compulsividade nem impulsividade. TE, de uma forma geral, teve uma associação robusta com os outros CRFC, diferenciando-se de TOC e de TJ. TE poderia ser classificado em uma sessão à parte juntamente com outros CRFC / Introduction: Excoriation Disorder (ED) is characterized by repetitive and excessive picking on healthy skin, resulting in significant skin damage and psychological distress associated with uncontrollable urge and failure to control this repetitive behavior. ED is currently classified under the Obsessive-compulsive and Related Disorders (OCRD) section of the Diagnostic and Statistics Manual of Mental Disorders - 5th edition. Nevertheless, there is still no consensus whether ED is more closely related to OCRDs or it would be better conceptualized as a behavioral addiction. Objectives: Compare ED patients with two paradigms of obsessive-compulsive disorders (OCD) and impulsive-addictive disorders (gambling disorder), analyzing their sociodemographic and clinical characteristics, diagnostic categories, comorbidity profile, obsessive-compulsive symptoms, impulsive traits, and personality features. The purpose of this comparison was to assess whether ED was more related to OCD-related disorders (OCDRD) or to behavioral addictions, e.g., Gambling Disorder (GD). Methods: Study participants were 121 patients seeking treatment at Instituto de Psiquiatria (IPq), Hospital das Clinicas da Faculdade de Medicina da Universidade Sao Paulo (HCFMUSP), Sao Paulo, Brasil. Of the 121 participants, 40 were diagnosed with ED, 41 with OCD, and 40 with GD. Structured clinical interviews were used to diagnose and compare the three groups in diagnostic overlap and current psychiatric-comorbidities, and standardized self-reports were used to evaluate the dimensional variables. Results: Participants in the ED group were more likely to be women, young, and with higher levels of education compared with those of the other groups. In the categorical analysis, ED was more significantly approached to OCD (n=14) than to GD (n=3), overlapping the first. In general, ED and OCD were also more likely to exhibit other body-focused repetitive behaviors (BFRB) and anxiety disorders. The presence of BFRB differentiated ED from GD. In contrast, ED differed from OCD by the presence of addictive behaviors. The dimensional analysis found that ED is a hybrid model of obsessive-compulsivity and impulsivity. Discussion: Categorical analysis supports the classification of ED as OCDRD; however, ED presented differences that may share underlying characteristics with OCD (e.g., compulsivity) and behavioral addiction (e.g., impulsivity). Dimensional analysis suggests a heterogeneous psychopathological in ED with both obsessive-compulsive and impulsive features. Correlation analysis shows that obsessive-compulsivity and impulsivity scores were not correlated to skin excoriation severity symptoms. The overall viewpoints to the allocation of ED points to its own diagnostic category, that is, Body-focused Repetitive Behaviors (BFRB). Conclusion: ED shows a peculiar demographic and clinical profile. ED and OCD share more similarities in the profile of psychiatric comorbidities than GD, mostly based on anxiety disorders. In contrast, ED differs from OCD by a more frequent association with addictive disorders. ED presented intermediate levels of compulsivity and impulsivity between OCD and GD in the dimensional approach. The excoriation behavior showed no relevant correlation with dimensional measures of compulsivity or impulsivity
70

Numerical Methods for Optimal Stochastic Control in Finance

Chen, Zhuliang January 2008 (has links)
In this thesis, we develop partial differential equation (PDE) based numerical methods to solve certain optimal stochastic control problems in finance. The value of a stochastic control problem is normally identical to the viscosity solution of a Hamilton-Jacobi-Bellman (HJB) equation or an HJB variational inequality. The HJB equation corresponds to the case when the controls are bounded while the HJB variational inequality corresponds to the unbounded control case. As a result, the solution to the stochastic control problem can be computed by solving the corresponding HJB equation/variational inequality as long as the convergence to the viscosity solution is guaranteed. We develop a unified numerical scheme based on a semi-Lagrangian timestepping for solving both the bounded and unbounded stochastic control problems as well as the discrete cases where the controls are allowed only at discrete times. Our scheme has the following useful properties: it is unconditionally stable; it can be shown rigorously to converge to the viscosity solution; it can easily handle various stochastic models such as jump diffusion and regime-switching models; it avoids Policy type iterations at each mesh node at each timestep which is required by the standard implicit finite difference methods. In this thesis, we demonstrate the properties of our scheme by valuing natural gas storage facilities---a bounded stochastic control problem, and pricing variable annuities with guaranteed minimum withdrawal benefits (GMWBs)---an unbounded stochastic control problem. In particular, we use an impulse control formulation for the unbounded stochastic control problem and show that the impulse control formulation is more general than the singular control formulation previously used to price GMWB contracts.

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