Submitted by Erika Demachki (erikademachki@gmail.com) on 2014-09-25T17:34:38Z No. of bitstreams: 2 Dissertação_Lucianna G. N. Lemes.pdf: 2661301 bytes, checksum: c0238e41dfbe2adbd10e5ddcff7a139e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-09-26T11:31:18Z (GMT) No. of bitstreams: 2 Dissertação_Lucianna G. N. Lemes.pdf: 2661301 bytes, checksum: c0238e41dfbe2adbd10e5ddcff7a139e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-09-26T11:31:18Z (GMT). No. of bitstreams: 2 Dissertação_Lucianna G. N. Lemes.pdf: 2661301 bytes, checksum: c0238e41dfbe2adbd10e5ddcff7a139e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-12-20 / The calicivirus (norovirus and sapovirus) are important etiologic agents of acute gastroenteritis. Recent studies show that in immunocompromised patients such as those undergoing allogeneic hematopoietic stem cell transplantation (HSCT), norovirus infection can lead to worsening of symptoms and be confused with clinical symptoms of graft versus host disease (GVHD). However, calicivirus screening is not performed, routinely, as part of the patients’ follow-up laboratory exams. The main objective of this study was to evaluate the occurrence of norovirus (NoV) and sapovirus (SaV) in patients who underwent HSCT, and to conduct the molecular characterization of the samples positive for these viruses. Fecal samples were collected weekly, and serum samples were obtained every two weeks of ten patients who underwent HSCT, for a minimum period of five months and a maximum of one year. The secretor status was determined by an enzyme immunoassay and the detection of calicivirus was performed by RT-PCR using primers specific for a partial region of the gene encoding the NoV genogroup I and II (GI and GII) and SaV capsid protein. The genomic sequencing was performed for positive samples. The results showed that from ten patients participating in the study, eight had diarrhea. Among these, six (60%) had positive samples for NoV, and all of them had a secretor phenotype. The duration of NoV excretion in feces ranged from five to 143 days. Viral RNA was also detected in serum specimens, ranging from 29 to 36 days in the five patients infected with NoV. Three of the six patients had acute intestinal GVHD. Through genomic sequencing and phylogenetic analysis all NoV-positive samples were characterized as genotype GI.3, and because they had a high nucleotide identity, they were all characterized as a single haplotype. The data highlight the urgent need of the inclusion of calicivirus screening in the routine testing performed before transplantation and during follow-up of these patients. This is the first report of the occurrence of NoV in patients undergoing HSCT in Brazil. / Os calicivírus (norovírus e sapovírus) são importantes agentes etiológicos da gastroenterite aguda. Estudos recentes mostram que em pacientes imunocomprometidos, como os submetidos a transplante alogênico de células progenitoras hematopoiéticas (TACPH), a infecção por norovírus pode levar ao agravamento dos sintomas e ser confundida com quadro clínico da doença do enxerto contra o hospedeiro (DECH). Entretanto, a triagem para calicivírus não é realizada, rotineiramente, como parte dos exames laboratoriais de acompanhamento destes pacientes. O principal objetivo deste estudo foi avaliar a ocorrência de norovírus (NoV) e sapovírus (SaV) em pacientes que foram submetidos ao TACPH e proceder à caracterização molecular das amostras positivas para estes vírus. Foram obtidas amostras de fezes, coletadas semanalmente, e de soro, a cada quinze dias, de dez pacientes que realizaram o TACPH, por um período mínimo de cinco meses e máximo de um ano. O fenótipo secretor dos pacientes foi determinado utilizando um teste imunoenzimático e a pesquisa de calicivírus foi realizada pela RT-PCR, utilizando-se iniciadores específicos para uma região parcial do gene codificante para a proteína dos capsídeos dos NoV do genogrupo I e II (GI e GII) e dos SaV. Os amplicons das amostras positivas foram submetidos ao sequenciamento genômico e análise filogenética. Os resultados obtidos revelaram que de dez pacientes participantes do estudo, oito apresentaram diarreia e vômito. Dentre esses, seis (60%) apresentaram amostras positivas para NoV, sendo que todos foram identificados como secretores. O período de excreção de NoV nas fezes variou de cinco a 143 dias. Foi também detectado RNA viral nas amostras de soro, variando de 29 a 36 dias, em cinco pacientes infectados por NoV. Três, dos seis pacientes, apresentaram DECH aguda intestinal. Através do sequenciamento genômico e análise filogenética, todas as amostras positivas para NoV, de todos os pacientes, foram caracterizadas como genótipo GI.3 dos NoV, e como foi comprovada elevada identidade nucleotídica entre elas, foram caracterizadas como um único haplótipo. Os dados obtidos ressaltam a urgente necessidade da inclusão da pesquisa de calicivírus na rotina de exames realizados antes do transplante, bem como durante o acompanhamento destes pacientes. Este é o primeiro relato da ocorrência de NoV em pacientes submetidos ao TACPH no Brasil.

abstract: Rabies is an infectious viral disease. It is usually fatal if a victim reaches the rabid stage, which starts after the appearance of disease symptoms. The disease virus attacks the central nervous system, and then it migrates from peripheral nerves to the spinal cord and brain. At the time when the rabies virus reaches the brain, the incubation period is over and the symptoms of clinical disease appear on the victim. From the brain, the virus travels via nerves to the salivary glands and saliva. A mathematical model is developed for the spread of rabies in a spatially distributed fox population to model the spread of the rabies epizootic through middle Europe that occurred in the second half of the 20th century. The model considers both territorial and wandering rabid foxes and includes a latent period for the infection. Since the model assumes these two kinds of rabid foxes, it is a system of both partial differential and integral equations (with integration over space and, occasionally, also over time). To study the spreading speeds of the rabies epidemic, the model is reduced to a scalar Volterra-Hammerstein integral equation, and space-time Laplace transform of the integral equation is used to derive implicit formulas for the spreading speed. The spreading speeds are discussed and implicit formulas are given for latent periods of fixed length, exponentially distributed length, Gamma distributed length, and log-normally distributed length. A number of analytic and numerical results are shown pertaining to the spreading speeds. Further, a numerical algorithm is described for the simulation of the spread of rabies in a spatially distributed fox population on a bounded domain with Dirichlet boundary conditions. I propose the following methods for the numerical approximation of solutions. The partial differential and integral equations are discretized in the space variable by central differences of second order and by the composite trapezoidal rule. Next, the ordinary or delay differential equations that are obtained this way are discretized in time by explicit continuous Runge-Kutta methods of fourth order for ordinary and delay differential systems. My particular interest is in how the partition of rabid foxes into territorial and diffusing rabid foxes influences the spreading speed, a question that can be answered by purely analytic means only for small basic reproduction numbers. I will restrict the numerical analysis to latent periods of fixed length and to exponentially distributed latent periods. The results of the numerical calculations are compared for latent periods of fixed and exponentially distributed length and for various proportions of territorial and wandering rabid foxes. The speeds of spread observed in the simulations are compared to spreading speeds obtained by numerically solving the analytic formulas and to observed speeds of epizootic frontlines in the European rabies outbreak 1940 to 1980. / Dissertation/Thesis / Doctoral Dissertation Applied Mathematics 2018

leadership styles homogeneous versus heterogeneous manufacturing leaders contractor workforce

Survival of patients with poor prognosis or relapsed haematopoietic malignancies can be markedly improved by allogeneic haematopoietic stem cell transplantation (HSCT). HSCT reconstitutes the immune and haematopoietic systems after myeloablative conditioning and inhibits the recurrence of the malignancy by a graft-versus-leukaemia (GVL) response mediated by donor T cells. However, significant post-transplant complications such as graft-versus-host disease (GVHD) continue to plague the event-free survival of this curative procedure. GVHD is facilitated by donor T cells that recognise histocompatibility antigens on host antigen presenting cells (APC), such as dendritic cells (DC). Current treatment options for GVHD are focused on these T cells. However, these treatments result in an increased incidence of infection, graft rejection and relapse. A novel means of immunosuppression in GVHD is the use of multi-potent, mesenchymal stromal cells (MSC). MSC are non-immunogenic cells that actively suppress T cell function in vitro, and can resolve steroid-refractory GVHD in the clinic. Despite their use in the clinic, there is a paucity of pre-clinical data. Our aim was to investigate the in vivo efficacy of MSC to control GVHD while maintaining the beneficial GVL effect, and to begin to understand the mechanism by which MSC exert their immunosuppressive effects. We isolated and characterised MSC from murine bone/bone marrow and demonstrated that they suppressed T cell proliferation in vitro, even at low ratios of 1 MSC per 100 T cells. This was true of both donor-derived MSC, and MSC derived from unrelated donors (third party). Importantly, we observed that MSC significantly reduced T cell production of the pro-inflammatory cytokines TNFα and IFNγ in culture supernatants and that IFNγ plays a key role in the ability of MSC to suppress T cell proliferation. In vivo, we examined the effects of donor-derived MSC on GVHD severity and onset in two myeloablative murine models of HSCT. A major histocompatibility complex (MHC)-mismatched donor-recipient pair combination was used as a proof–of-principle model [UBI-GFP/BL6 (H-2b)àBALB/c (H-2d)], and an MHC-matched, minor histocompatibility antigen (miHA) mismatched donor-recipient pair combination was used to mimic MHC-matched sibling transplantation [UBI-GFP/BL6 (H-2b)àBALB.B (H-2b)]. We examined a number of variables related to MSC infusion including timing, dose and route of injection. We found that early post transplant infusion of MSC by the intraperitoneal injection was most effective at delaying death from GVHD, compared to pre-transplant infusion or intravenous injection. Furthermore, we found that the dose of MSC was critical, as infusion of too few MSC was ineffective and infusion of too many MSC exacerbated the development of GVHD. Taken together, these results suggest that timing, dose and route of injection are all important factors to be considered to ensure successful therapeutic outcome. To investigate the in vivo mechanism of action, we conducted timed sacrifice experiments in the MHC-mismatched model to determine if MSC altered cytokine secretion and cellular effectors, such as DC, known to play a key role in GVHD. Despite the fact that MSC given post-HSCT enter an environment full of activated DC and IFNγ levels, by day 3 and 6 post infusion, these activated DC and IFNγ levels are decreased compared to controls or mice infused with MSC pre-transplant (p<0.05). This confirmed our in vitro data that IFNγ played an important role in MSC-mediated immunosuppression. In addition, when we removed a major source of IFNγ production in vivo by administering the T cell depleting antibody KT3 to mice with or without MSC, we found that although T cell depletion prolonged survival, MSC were unable to further enhance this effect. This was also true when MSC were used in combination with the conventional immunosuppressant cyclosporine. Finally, we examined whether the infusion of MSC would compromise the GVL effect. We found that whilst MSC could delay the onset of GVHD, in our model they did not alter the anti-tumour effects of the donor T cells. Overall, we have shown that MSC can delay but not prevent death from GVHD when administered at an appropriate time and dose and that IFNγ is required for MSC-mediated immunosuppression in our model. These data suggest that patients undergoing HSCT should be monitored for IFNγ, and administered MSC when high levels are reached. Whilst MSC may be a promising therapy for patients with severe GVHD, we highlight that further investigation is warranted before MSC are accepted for widespread use in the clinic. The risks and benefits for transplant recipients should be carefully considered before utilising MSC to treat or prevent GVHD.

Notre travail de thèse porte sur la modélisation des intentions de communications des systèmes de dialogue homme-machine en langue naturelle et de manière générale de tout agent logiciel. Il s'agit de proposer un modèle de fonctionnement permettant à la machine d'avoir ses propres intentions de communiquer avec l'utilisateur humain, de telle sorte que la pertinence optimale de ses énonciations soit garantie.<br /><br />Notre modèle s'appuie sur l'idée que le sens échangé entre les interactants d'une conversation n'est pas un sens pré-existant à celle-ci, mais au contraire, un sens négocié et co-construit par les interactants durant la conversation. Cette co-construction s'appuie sur l'hypothèse de l'existence d'un terrain commun, c'est-à-dire d'un ensemble de connaissances, hypothèses et croyances que le locuteur pense être partagées.<br /><br />Notre travail a consisté à définir une mémoire interactionnelle pour la machine permettant le travail de négociation du sens. Cette mémoire contient des éléments de différents états organisés en arborescences. Ces éléments proviennent de l'interprétation des actes illocutoires de l'utilisateur et des résultats des raisonnements faits par les différentes activités du système de dialogue. Nous distinguons l'activité applicative dont le but est de fournir un service quelconque à l'utilisateur, l'activité langagière qui consiste à analyser les énoncés de l'utilisateur et générer les énoncés du système, et enfin l'activité dialogique qui consiste à dialoguer avec l'utilisateur. Les intentions de communications de la machine sont générées par la reconnaissance de configurations remarquables que nous avons définies en étudiant les arborescences qu'il est normalement possible d'obtenir. Ce principe de génération, à l'origine des actes langagiers de la machine, est général et indépendant de l'application. Il s'appuie uniquement sur la forme structurelle des éléments mnésiques (appelé UMM pour Unité Minimale de Mémoire) et sur le statut de ces derniers.

<p>Our aim with this essay is to examine if social work in the care of elderly tends to be salutogenetic or patogenetic oriented. A salutogenetic oriented activity means that the social workers focuses on the elderly peoples individual possibilities, and collaborate with the receiver of care in order to offer him or her aid and resources for meaningful living conditions. A patogenetic oriented activity on the other hand means that the social workers focuses on the elderly peoples most primary needs, their illnesses and to introduce adequate treatment. We also examine if social workers in the care of elderly tend to prefer male or female characteristic features in the receivers of care. Finally we wanted to find out if there were any gender distinctions, if the appraisal of aid were more affected by a male or female receiver of care. We also considered that gender might not have any affect on their appraisal at all.</p><p>Our theoretical framework is mainly based on three already existing theories. These gave us a general list of salutogenetic/patogenetic statements and typical male/female characteristic features. Because of time shortage the material includes only one empirical method, which is a questionnaire to the employees in the care of the elderly. The method of analysis is mostly quantitative, but since the questionnaire also contained some opened questions, our study is partly qualitative. A total of 101 persons participated in our questionnaire poll. The results of our study brought about unexpected results. To our surprise, the social workers in the care of elderly tend to prefer male characteristic features in the receivers of care. We also found that what requires of a good apraisal of aid is a salutogenetic perspective, but that the social workers thought it was difficult to apply in practice.</p>

Ce travail étudie les composants de l'évolution territoriale et socio-économique de la région du Jari, située au nord de l'Amazonie brésilienne, en identifiant les différents processus de transformation ainsi que les structures spatiales actuelles. Longtemps à l'écart des dynamiques nationales du peuplement et du développement, celle-ci connait, au XXe siècle, un développement socioéconomique en deux étapes : Le premier, au début du siècle, à partir d'une occupation conditionnée par l'extractivisme (exploitation de ressources naturelles de la forêt, comme le caoutchouc ou la noix du Brésil), et organisée autour d'un latifundiaire sur environ 2 millions d'hectares. Le deuxième, plus important, à la fin des années 1960, à partir de l'installation, sur ce même territoire, d'une grande entreprise agro-industrielle, le " projet Jari ", par l'entrepreneur et multimillionnaire Américain D.K. Ludwig, qui visait à la production de la cellulose à grande échelle, et entraînait la construction d'une première infrastructure urbaine et industrielle dans une région de forêt primaire jusque-là intacte. Désormais indissociablement liées, les transformations socioéconomiques et territoriales de la région du Jari se sont depuis produites en tant qu'influence ou interaction directe avec l'évolution du projet Jari. Celui-ci, toujours en fonction dans la région aujourd'hui, a lui-même connu des transformations significatives depuis son installation en 1967: fortement polémiquée pour la non rentabilité économique, l'impact environnemental, et le gaspillage en ressources humaines de ses activités d'agrobusiness, le projet Jari du XXIe siècle émerge aujourd'hui, sous une nouvelle gestion (Orsa), comme une entreprise viable, certifiée, et pionnière en matière de responsabilité sociale et environnementale des entreprises en contexte amazonien. Les nouvelles stratégies territoriales développées par celle-ci et basées dans un discours de responsabilité sociale et environnementale des entreprises, ont permis à la Jari non seulement de conquérir une place stable sur le marché national et international de la cellulose, mais aussi à atténuer une conflit foncier de long date dans la région du Jari, qui a durablement marqué les relations entre l'entreprise, le gouvernement et les populations locales, dont plusieurs ont été déplacées de leurs terres lors de la transformation de larges parties de forêt primaire en plantations d'eucalyptus. La création, par la " nouvelle " entreprise, d'une Fondation sociale, censée de mettre en œuvre des petits projets socio-économiques dans la région, a en outre permis d'avancer le processus d'intégration territoriale visant à inclure enfin les communautés locales et les acteurs politiques à la gestion régionale et à l'utilisation des ressources, jusque-là monopolisée par l'entreprise. Sans être achevé, ce processus forme aujourd'hui la base solide pour une transformation " durable " du Jari, d'une vieille "enclave " économique de l'Américain à une région intégrée dont le potentiel est partagé parmi ses habitants.

Nous avons montré que l'irradiation aux ions d'argon d'énergie comprise entre 1 et 15 MeV cause des dommages en surface du titane et du zirconium, qui prennent la forme d'une oxydation accélérée et/ou d'une cratérisation dont les effets évoluent en fonction de l'énergie du projectile et de l'atmosphère de recuit (température et pression), simulant les conditions environnementales représentatives de l'interface gaine/combustible d'un réacteur REP. Par AFM, nous avons montré que la surface du titane et du zirconium était attaquée par bombardement aux ions d'argon, à haute température (jusqu'à 500°C) en milieu faiblement oxydant (sous pression d'air sec raréfié comprise entre 5,7 10-5 Pa et 5 10-3 Pa) et à une dose moyenne fixée à environ 5 1014 ions.cm-2. On observe ainsi la formation de cratères nanométriques sur toute la surface du titane irradié entre 2 et 9 MeV et celle du zirconium irradié à 4 MeV, dont les caractéristiques varient en fonction de la température et de la pression. Dans le cas du couple Ar/Ti, l'efficacité d'endommagement superficiel augmente lorsque l'énergie du projectile diminue de 9 à 2 MeV. Par ailleurs, alors que la surface du titane apparaît transparente au faisceau d'ions à 15 MeV, celle du zirconium révèle de nombreux cratères micrométriques entourés d'un large halo sombre. Les caractéristiques des cratères (taille et densité superficielle) diffèrent de façon significative de celles observées à la fois dans le domaine des basses énergies (keV) où le dépôt d'énergie est contrôlé par les collisions balistiques (Sn) et dans le domaine des hautes énergies (MeV - GeV) où le dépôt d'énergie est contrôlé par les excitations électroniques (Se), ce qui n'était pas complètement inattendu dans le domaine d'énergie intermédiaire étudié, dans lequel des effets de pouvoir d'arrêt combiné Sn - Se sont envisageables. Par XPS couplé au décapage ionique, nous avons montré qu'il existe un effet d'irradiation sur l'oxydation thermique du titane, exacerbée sous faisceau d'ions d'argon entre 2 et 9 MeV, et qu'il existe aussi un effet d'énergie sur l'épaisseur et la stœchiométrie de l'oxyde. L'étude menée par Ellipsométrie Spectroscopique sur les films d'oxyde formés entre 1 et 9 MeV a corroboré ces résultats et montré précisément qu'il existe un pic d'oxydation en fonction de l'énergie d'ions d'argon, qui présente un maximum à 3 MeV, dans les conditions de l'expérience. Les mesures de gain d'oxygène effectuées par NBS confirment l'existence de ce pic d'oxydation. Les résultats acquis à ce jour par NBS concernant l'oxydation thermique du zirconium sous irradiation à l'argon de 4 et 9 MeV confirment les travaux antérieurs du groupe Aval du Cycle Electronucléaire de l'Institut de Physique Nucléaire de Lyon, et suggèrent fortement l'existence d'un pic d'oxydation dans la même plage d'énergie de projectile que pour le titane.

The Fas pathway is critical for the maintenance of normal T cell homeostasis. Humans and mice with defects in this pathway exhibit the accumulation of large numbers of peripheral lymphocytes and lupus-like autoimmunity. A major feature of these organisms is the accumulation of non-NK TCRαβ+CD4-CD8- “double negative” (DN) T cells. While regulatory T cells (Tregs) with the DN phenotype have been extensively characterized in Fas-sufficient mice and humans, limited data exist on the role of DN T cells as Tregs in Fas-deficient animals. In fact, most of the literature suggests that the DN T cells accumulating in Fas-deficiency states are pathogenic, contributing to secondary lymph node enlargement and autoimmune disease. In this body of work, data are presented that illustrate that Fas-deficient lymphoproliferative (LPR) DN T cells can act as Tregs in an interferon γ (IFNγ)- and Fas ligand (FasL)-dependent fashion toward Fas-sufficient T cells. LPR DN T cells needed to be able to secrete and respond to IFNγ in order to upregulate surface FasL, in order to ameliorate GVHD mediated by CD4+ T cells in vivo and to suppress the proliferation of and kill activated CD4+ T cells in vitro. FcRγ, a key molecule involved in innate immune responses, can substitute for CD3ζ in the T cell receptor (TCR) of mouse and human T cells in certain circumstances; in doing so, it is essential for the regulatory function of TCR transgenic DN Tregs. FcRγ-deficient LPR mice were found to have exacerbated T cell accumulation and early mortality. We show that while FcRγ expression was required for LPR DN T cells to regulate CD4+ and CD8+ T cells responding to alloantigens in vitro and in vivo, it does not control autologous lymphoproliferation in LPR mice by supporting the function of a regulatory cell, nor does it affect the rate of proliferation of LPR T cells in vivo. Instead, FcRγ-expressing LPR CD4+, CD8+ and DN T cells were found to be undergoing apoptosis at a high rate in vivo, and in contrast to their FcRγ-deficient counterparts, FcRγ+ LPR DN T cells were capable of undergoing TCR restimulation-induced cell death (RICD). The data presented in this thesis therefore show that LPR DN T cells can exhibit IFNγ-, FasL- and FcRγ-dependent regulatory function, and also illustrate a previously unknown function for FcRγ in controlling the expansion of Fas-deficient T cells. The implications of these data for autoimmune lymphoproliferative syndromes, and normal T cell homeostasis, are discussed.

Phase transitions and other intrinsic properties (shape, size, architecture) of molecularly structured aerosol particles are important for understanding their role in planetary atmospheres and for technical applications. By combining bath gas cooling with time resolved mid-infrared spectroscopy and modeling, information is obtained on dynamic processes and intrinsic properties of fluoroform and ethane aerosol particles. The distinct infrared spectral features of fluoroform aerosol particles make it a particularly suitable model system. Homogeneous crystallization rates of the sub-micron sized aerosol particles are determined (JV = 10⁸ - 10¹⁰ cm-³s-¹ or JS = 10³ – 10⁵ cm-²s-¹ at a temperature of T = 78 K), and the controversial question regarding volume versus surface nucleation in freezing aerosols is addressed. It is demonstrated that current state of the art measurements of droplet ensembles cannot distinguish between the two mechanisms due to inherent experimental uncertainties. The evolution of particle shape from spherical supercooled droplets to cube-like crystalline particles and eventually to elongated crystalline particles is recorded and analyzed in detail with the help of vibrational exciton model calculations. Phase behaviour of pure ethane aerosols and ethane aerosols formed in the presence of other ice nuclei under conditions mimicking Titan’s atmosphere provide evidence for the formation of supercooled liquid ethane aerosol droplets, which subsequently crystallize. The observed homogeneous freezing rates (JV = 10⁷ – 10⁹ cm-³s-¹) imply that supercooled ethane could play a similar role in ethane rich regions of Titan’s atmosphere as supercooled water does in the Earth’s atmosphere.