491 |
Chapter 1: In Search of Innate Leadership : Discovering, Evaluating and Understanding InnatenessMorra, Erica, Zenker, Lisa January 2014 (has links)
Every individual is born with different natural competencies that can be honed by both voluntary and involuntary environmental stimuli. The response our genotype decides to make, if any, towards those stimuli, determines how well our competencies develop. Each person’s coding and variations of genes will result in unique qualities in their phenotype, or physical structure. As a result, a person has various traits that are displayed through their behavior. DNA is genetically shown to express itself through traits by up to 75%. This leaves a sort of buffer of around 25%. This region is available for us to adapt to our environmental stimuli. Your innate qualities will not reach their full potential without stimulation from the environment, in a leadership case, with education and training and therefore it can be argued that environmental exposure is necessary to fully expose the potentials and capabilities of an individual, rather than instill a new skill or develop a talent that was not existent before. Innate leadership is not a permanent state, on the contrary, it is a continuously adaptive situation demanding contextual evolutionary changes or resignation from the subject occupying the role. When the needs and demands of a society or era outweigh the relevance of the innate leaders' traits and competencies, an evolution of leadership is needed to maintain a positive relationship between all parties involved. As a result, the innate leader will begin to lose their innateness in their role and unless they evolve and adapt (because the two actions are not the same) to new contextual needs, their tenure as leader will begin to be detrimental and counter-functional. What we want to put forward is a real, universal and constructive understanding of what makes a human happy, motivated and productive and how an innate person in context is a much better solution in the short and long run, for those around them when put to a task.
|
492 |
Προηγμένα περοβσκιτικά ηλεκτρόδια για ενεργειακές και καταλυτικές εφαρμογές / Advanced perovskitic electrodes for energy and catalytic applicationsΚουρνούτης, Βασίλειος 20 April 2011 (has links)
Το ενδιαφέρον για την ανάπτυξη νέων καθοδικών ηλεκτροδίων για χρήση τους σε κυψέλες καυσίμου στερεού ηλεκτρολύτη (SOFCs) ενδιάμεσων θερμοκρασιών (600-800oC) γίνεται ολοένα και μεγαλύτερο, δεδομένου ότι η απόδοση των συμβατικών καθόδων La1-xSrxMnO3-δ δεν είναι ικανοποιητική σε θερμοκρασίες χαμηλότερες των 800oC. Περοβσκιτικά υλικά με γενικό τύπο La1-x-ySrxCozFe1-zO3-δ αποτελούν υποσχόμενη εναλλακτική λύση, εξαιτίας της υψηλής ηλεκτρονικής και ιοντικής τους αγωγιμότητας. Η μικτή τους αυτή αγωγιμότητα έχει ως αποτέλεσμα τη διεύρυνση της ζώνης αντίδρασης και την ταχύτερη κινητική της αντίδρασης αναγωγής του οξυγόνου.
Στην παρούσα εργασία πραγματοποιήθηκε ηλεκτροχημικός χαρακτηρισμός με φασματοσκοπία σύνθετης αντίστασης, μετρήσεις πυκνότητας ρεύματος-υπέρτασης και κυκλική βολταμετρία, περοβσκιτικών καθοδικών ηλεκτροδίων La1-x-ySrxCo2Fe0.8O3-δ και La1-x-ySrxFeO3-δ σε επαφή με CGO/YSZ. Από την ανάλυση των πειραμάτων σύνθετης αντίστασης προέκυψε ως κύριο συμπέρασμα ότι ανάλογα με τη θερμοκρασία, τη μερική πίεση οξυγόνου και την πόλωση, τα χαρακτηριστικά σύνθετης αντίστασης του ηλεκτροδίου La0.8Sr0.2Co0.2Fe0.8O3-δ καθορίζονται από μέχρι τρεις διαφορετικές διεργασίες, οι οποίες αναγνωρίστηκαν ως αγωγή ιόντων οξυγόνου διά του ηλεκτροδίου, διαφασική μεταφορά φορτίου με συμμετοχή ατομικού οξυγόνου και διάχυση O2 στην αέρια φάση. Με ανάλυση μετρήσεων πυκνότητας ρεύματος ως προς την υπέρταση και το δυναμικό του ηλεκτροδίου, προσδιορίστηκαν επίσης, οι τιμές των ηλεκτροκινητικών παραμέτρων (πυκνότητα ρεύματος ανταλλαγής, συντελεστές μεταφοράς) που αφορούν στην ηλεκτροχημική αντίδραση αναγωγής του οξυγόνου και η αγωγιμότητα πόλωσης ως συνάρτηση του εφαρμοζόμενου δυναμικού για διάφορες θερμοκρασίες.
Η τεχνική της κυκλικής βολταμετρίας εφαρμόστηκε για χαρακτηρισμό των παραπάνω περοβσκιτικών ηλεκτροδίων (x = 0.2; 0.4 και y = 0; 0.02), προκειμένου να αναγνωριστούν οι ηλεκτροχημικές διεργασίες που λαμβάνουν χώρα υπό συνθήκες πόλωσης. Η εμφάνιση κορυφών ρεύματος στα κυκλοβολταμογραφήματα, σε μία ευρεία περιοχή θερμοκρασιών, μερικών πιέσεων οξυγόνου και ρυθμών σάρωσης του δυναμικού, συσχετίστηκε με ηλεκτροχημικές αντιδράσεις αναγωγής-οξείδωσης ιόντων σιδήρου ή/και κοβαλτίου αλλά και με οξείδωση-αναγωγή ειδών οξυγόνου.
Τέλος, αξιολογήθηκε η καταλυτική ενεργότητα περοβσκιτικών οξειδίων με γενικό τύπο La1-x-ySrxCozFe1-zO3-δ για πλήρη οξείδωση CO και CH4. Ως κύριο συμπέρασμα προέκυψε ότι τα περοβσκιτικά οξείδια LSCF παρουσιάζουν υψηλότερη καταλυτική ενεργότητα σε σχέση με τα οξείδια LSF. / Recently, there has been a lot of focus on the development of new cathode materials for use in intermediate temperature (600–800°C) solid oxide fuel cells, since the conventional cathodes based on La1–xSrxMnO3–δ do not perform satisfactorily below 800°C. Iron- and cobalt-containing perovskites La1–x–ySrxCozFe1–zO3–δ have recently attracted significant attention as promising alternative cathode materials for IT-SOFCs, mainly due to their high mixed (electronic and ionic) conductivity, which results in enlargement of the available electrochemically active area, and their high oxygen surface exchange coefficients.
In the present work electrochemical characterisation was carried out on porous La1–x–ySrxCo0.2Fe0.8O3–δ (LSCF) and La1–x–ySrxFeO3–δ (LSF) cathode electrodes deposited via screen-printing on the CGO layer of a CGO/YSZ electrolyte, using AC impedance spectroscopy, current density vs. electrode overpotential measurements, and cyclic voltammetry. From the analysis of the experimental results it was concluded that depending on temperature, oxygen partial pressure and polarization, the impedance characteristics of the La0.8Sr0.2Co0.2Fe0.8O3-δ electrode are determined by up to three different processes, which were identified as ionic conduction in the electrode bulk, interfacial charge transfer and gas phase diffusion, respectively. The values of the electrokinetic parameters of the electrochemical oxygen reduction as well as the polarization conductance, were determined as a function of the applied electrode potential at different temperatures, based on the analysis of current density vs. electrode overpotential measurements.
Cyclic voltammetry technique was used in order to identify the electrochemical processes taking place under cathodic polarization on the basis of differences in the features of the cyclic voltammograms with changing conditions. Depending on the electrode, temperature, oxygen partial pressure and potential sweep rate, the appearance of current peaks was related to the electrochemical redox of B-sites and concomitant stoichiometry change as well as to the competing reaction of electrochemical oxygen redox, taking also into account the competitive action of chemical reactions which may occur in the presence of O2.
Finally, the present work aimed to the assessment of the catalytic activity of these perovskite oxides for CO and CH4 combustion and it was found that LSCF perovskites were more catalytically active than LSF perovskites.
|
493 |
Ανάπτυξη μεθοδολογίων υπολογιστικής νοημοσύνης για την επεξεργασία και ανάλυση δεδομένων γονιδιακής έκφρασης μικροσυστοιχιών cDNAΣηφάκης, Εμμανουήλ Γ. 08 July 2011 (has links)
Στην παρούσα διδακτορική διατριβή προτείνονται μεθοδολογίες υπολογιστικής νοημοσύνης για την επεξεργασία και ανάλυση δεδομένων γονιδιακής έκφρασης μικροσυστοιχιών cDNA. Πιο συγκεκριμένα, στο πρώτο σκέλος αναπτύσσονται δύο νέες προσεγγίσεις για την εύρωστη εκτίμηση και διόρθωση του θορύβου υποβάθρου: η διόρθωση υποβάθρου βάσει εκατοστημορίων και η διόρθωση υποβάθρου βάσει παλινδρόμησης loess. Οι προσεγγίσεις αυτές καινοτομούν κυρίως στο ότι χρησιμοποιούν μία εύρωστη εκτίμηση του θορύβου υποβάθρου, γεγονός που τις καθιστά ιδανικές σε περιπτώσεις, όπου τα δεδομένα είναι θορυβώδη. Επιπροσθέτως, αναπτύσσεται ένα νέο, γενικής χρήσεως, πλαίσιο για τη συστηματική αξιολόγηση του βαθμού επίδρασης των μεθόδων διόρθωσης υποβάθρου. Μέσω του πλαισίου αυτού, οι δύο προτεινόμενες προσεγγίσεις, καθώς και άλλες ευρέως χρησιμοποιούμενες μέθοδοι, αξιολογούνται βάσει εφαρμογής τους σε διαφορετικά σύνολα δεδομένων αυτο-υβριδοποίησης, με τις πρώτες να εμφανίζουν ιδιαιτέρως καλή απόδοση. Το πλαίσιο αυτό καινοτομεί στο ότι ενσωματώνει νέα κριτήρια και τρόπους γραφικής απεικόνισης. Τόσο οι προτεινόμενες μέθοδοι εκτίμησης και διόρθωσης θορύβου υποβάθρου, όσο και το πλαίσιο συστηματικής αξιολόγησής τους, συνιστούν μία νέα, ενδελεχή μελέτη που προσανατολίζει στην εφαρμογή ή απόρριψη μίας συγκεκριμένης προσέγγισης, συνεισφέροντας εν τέλει στην κατάκτηση καλλίτερης ποιότητας δεδομένων μικροσυστοιχιών. Επίσης, στο δεύτερο σκέλος της διατριβής αναπτύσσεται ένα νέο, ολοκληρωμένο και γενικής χρήσεως πλαίσιο ανάλυσης δεδομένων μικροσυστοιχιών ούτως, ώστε να διερευνηθεί το ζήτημα εάν στην T-λευχαιμική κυτταρική σειρά CCRF-CEM επικρατούν εγγενείς ή επίκτητοι μηχανισμοί αντοχής στην πρεδνιζολόνη. Συγκεκριμένα, καταλλήλως επιλεχθέντα δεδομένα μικροσυστοιχιών cDNA – που διευκολύνουν την εξέταση τόσο της εξαρτώμενης από τη συγκέντρωση δράσης, όσο και της δυναμικής της ανταπόκρισης στην πρεδνιζολόνη (πρώιμη και όψιμη δράση) – γίνονται αντικείμενο επεξεργασίας και ενδελεχούς ανάλυσης, και βάσει συγκεκριμένων, προ-διατυπωμένων συλλογισμών, προσεγγίζεται το εν λόγω ερώτημα. Το πλαίσιο αυτό είναι καινοτόμο, εφόσον, πέραν του ότι ενσωματώνει μία πρωτότυπη ακολουθία μεθόδων, προσεγγίζει συστηματικά το πρόβλημα της εγγενούς ή επίκτητης αντοχής, συνεισφέροντας, έτσι, στην ευρύτερη προσπάθεια διερεύνησης των επακριβών μηχανισμών αντοχής των λευχαιμικών κυττάρων στα γλυκοκορτικοειδή. Τα αποτελέσματα από την εφαρμογή του στα δεδομένα της εν λόγω κυτταρικής σειράς συνηγορούν υπέρ της ύπαρξης μίας σύνθετης ανταπόκρισης του υπό μελέτη συστήματος στα γλυκοκορτικοειδή, η οποία όμως τείνει περισσότερο προς έναν εγγενή μηχανισμό αντοχής. / In the present Ph.D. thesis, computational intelligence methods for processing and analyzing cDNA microarray gene expression data are designed and developed. More specifically, in the first part of this thesis, the problem of background estimation and correction of two-channel microarray data is addressed and two novel algorithms are proposed, namely the percentiles-based and the loess-based background correction methods. Both approaches are based on the multiplicative model of background, while utilizing robust background noise estimators, thus making them ideal for noisy datasets. Furthermore, a new, generic framework for the systematic evaluation of the impact of the background estimating methodologies is suggested, whereupon the aforementioned methods as well as other approaches are evaluated by application to various publicly available self-self hybridization datasets. As suggested by this thorough, comparative evaluation our algorithms perform very well regarding noise reduction. The evaluation framework, which is based mainly on different and widely used statistical measures, incorporates new criteria and visualization methods. Moreover, it represents a novel, detailed contribution to the examination of the impact of background correction methods to the final interpretation of microarray experiments, conferring explicit guidance on the pros and cons of them and when they should be applied. Additionally, in the second part of this thesis, a new, generic, computational microarray data analysis framework is described, in order to examine the hypothesis of whether the resistant T-cell leukemia cell line CCRF-CEM posses an intrinsic or exert an acquired mechanism of resistance and to investigate the molecular imprint of this, upon prednisolone treatment. More analytically, using the above explained computational analysis workflow, microarray data that enable the examination of both the dose effect of prednisolone exposure and the dynamics (early and late) of the molecular response of the cells at the transcriptomic layer, are systematically analyzed based on specific, predefined formulations. The analysis of the results supports a complex mechanism of action for the cells which seems to favor though more the intrinsic mechanism of resistance.
|
494 |
CD40-CD154 Blockade Facilitates Induction of Allogeneic Hematopoietic Chimerism and Transplantation Tolerance: A DissertationSeung, Edward 14 May 2003 (has links)
Allogeneic hematopoietic chimerism leading to central tolerance has significant therapeutic potential. Establishment of hematopoietic chimerism created by stem cell transplantation has been shown to prevent and cure a number of autoimmune diseases and induce the most robust and long-lasting form of transplantation tolerance known. However, the realization of the vast clinical potential of hematopoietic chimerism for induction of transplantation tolerance has been impeded by the toxicity of the host conditioning regimen and the development of graft-versus-host disease (GVHD). This thesis describes the development of stem cell transplantation protocols that 1) reduce the host conditioning regimen; and 2) abrogate the development of GVHD. When applied to the treatment of autoimmune diabetic NOD mice, a model of type 1 diabetes, stem cell transplantation was able to 3) prevent autoimmune recurrence; and 4) permit curative pancreatic islet transplantation.
I first describe a tolerance-based stem cell transplantation protocol that combines sub-lethal irradiation with transient blockade of the CD40-CD154 costimulatory pathway using an anti-CD154 antibody. With this protocol, I established hematopoietic chimerism in BALB/c mice transplanted with fully allogeneic C57BL/6 bone marrow. All chimeric mice treated with anti-CD154 antibody remained free of graft vs.host disease (GVHD) and accepted donor-origin but not third party skin allografts. It was similarly possible to create allogeneic hematopoietic chimerism in NOD/Lt mice with spontaneous autoimmune diabetes. Pancreatic islet allografts transplanted into chimeric NOD/Lt mice were resistant not only to allorejection but also to recurrence of autoimmunity. I conclude that it is possible to establish robust allogeneic hematopoietic chimerism in sub-lethally irradiated mice without subsequent GVHD by blocking the CD40-CD154 costimulatory pathway using as few as two injections of anti-CD154 antibody. I also conclude that chimerism created in this way generates donor-specific allograft tolerance and reverses the predisposition to recurrent autoimmune diabetes in NOD/Lt mice, enabling them to accept curative islet allografts.
In order to further reduce the impediments associated with the implementation of allogeneic hematopoietic chimerism as a therapeutic modality, I adapted a costimulation blockade-based protocol developed for solid organ transplantation for use in stem cell transplantation. The protocol combines a donor-specific transfusion (DST) with anti-CD154 antibody to induce peripheral transplantation tolerance. When applied to stem cell transplantation, administration of DST, anti-CD154 antibody, and allogeneic bone marrow led to hematopoietic chimerism and central tolerance with no myeloablation (i.e. no radiation) and no GVHD in 3 different strains of mice. The development of donor-specific tolerance in this system was shown to involve deletion of both peripheral host alloreactive CD8+ T cells and nascent intrathymic alloreactive CD8+ T cells. In the absence of large numbers of host alloreactive CD8+ T cells, the cell transfusion that precedes transplantation need not be of donor-origin, suggesting that both allo-specific and non-allo-specific mechanisms regulate engraftment. Agents that interfere with peripheral transplantation tolerance partially impair establishment of chimerism. I conclude that robust allogeneic hematopoietic chimerism and central tolerance can be established in the absence of host myeloablative conditioning using a peripheral transplantation tolerance protocol.
|
495 |
Uma festa para a Rainha da Borborema: O Centenário de Campina Grande (1960 - 1964). / A party for the Queen of Borborema: The Centennial of Campina Grande (1960 - 1964).AGUIAR, Joabe Barbosa. 09 October 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-10-09T14:42:49Z
No. of bitstreams: 1
JOABE BARBOSA AGUIAR -DISSERTAÇÃO PPGH 2014..pdf: 7832554 bytes, checksum: f8139e11a91775ca3117629fdb0558f5 (MD5) / Made available in DSpace on 2018-10-09T14:42:49Z (GMT). No. of bitstreams: 1
JOABE BARBOSA AGUIAR -DISSERTAÇÃO PPGH 2014..pdf: 7832554 bytes, checksum: f8139e11a91775ca3117629fdb0558f5 (MD5)
Previous issue date: 2014-05 / Como leitores ávidos por novos horizontes e paisagens do passado, convido-lhes para
esta trajetória em busca de novos significados sobre o centenário de Campina Grande
(1964). Trata-se de uma investigação acerca da teatralização do poder, tendo como
suporte a construção simbólica e imagética. Conduzimos teoricamente nossa pesquisa a
partir do debate com a Nova História Política, nessa fundamentação, diálogo com os
autores do campo da teatrocracia, como Balandier e Geertz. Adotamos como fonte de
pesquisa o jornal Diário da Borborema que circulava no período em análise, além dos
livros de Ata da Câmara dos Vereadores de Campina Grande, músicas produzidas para
o centenário, álbum de figurinhas e fotografias sobre o evento festivo.
Metodologicamente nos pautamos pela análise das falas, impressões e observações
produzidas do contato com nossas fontes, com a preocupação de irmos além do
meramente escrito, no sentido de compreender seus discursos como resultantes das
relações de poder. Neste cenário, pretendemos decodificar as festas, os ritos e os
cerimoniais como as letras de um alfabeto. / As readers eager for new horizons and landscapes of the past, invite them to this path in
search of new meanings about the centenary of Campina Grande (1964). This is an
investigation about the theatricality of power, supported the construction and symbolic
imagery. We conduct our research theoretically from the debate with the New Political
History, in this reasoning, dialogue with the authors in the field of teatrocracia as
Balandier and Geertz. We adopt as a research newspaper Diário da Borborema that
circulated in the period, and the books of the Minutes of the City Council of Campina
Grande, songs produced for the centenary, sticker album and photographs about the
festive event. Methodologically we have guided the analysis of discourse, impressions
and observations produced contact with our sources, with the worry of going beyond the
purely written, in order to understand their speech because of power relations. In this
scenario, we want to decode the festivals, rites and ceremonies like the letters of an
alphabet.
|
496 |
Estudo das empresas concordatárias e alterações no sistema falimentar brasileiroPiza, Sofia Ramos de Toledo 13 April 2004 (has links)
Made available in DSpace on 2010-04-20T20:51:24Z (GMT). No. of bitstreams: 0
Previous issue date: 2004-04-13T00:00:00Z / Analysis and, criticism of the proposed changes in Brazilian bankruptcy legislation based on an empiric study of Brazilian companies under debt rehabilitation (concordata) proceedings during the period from 1992 to 2002. Identification of the main features of the companies that petitioned for concordata (mainly in relation to their profitability) and moreover, identify the companies that were able to recover, using them as a basis to substantiate critical analysis of the bill for the new bankruptcy legislation, and presentation of suggestions to increase the recovery rates of companies facing financial difficulties. Comparison of the proposed changes with the current United States Law (Chapter 11), which is known to be more efficient in the recovery of companies in financial straits. / Análise e crítica das alterações propostas à legislação falimentar brasileira tendo como base o estudo empírico de empresas brasileiras que entraram em concordata no período de 1992 a 2002. Identificação das principais características das empresas que pedem concordata (principalmente quanto a sua lucratividade) e também das empresas que conseguem se recuperar e uso das mesmas como base para uma análise crítica do projeto da nova legislação falimentar, bem como apresentação de sugestões que visem aumentar as taxas de recuperação de empresas em dificuldades financeiras. Comparação das alterações propostas com a legislação norte americana atual (Chapter 11), que é reconhecidamente mais eficiente na recuperação de empresas em dificuldades.
|
497 |
Effects of English as medium of instruction on pupils' academic achievement in social studies in primary schools in MalawiMchazime, Hartford Skaliot 01 January 2002 (has links)
The current language policy in education in Malawi allows pupils to be taught through local languages form Standard 1 to 4 and through English from Standard 5 upwards. However, classroom observation suggets that teachers use Chichewa as the language of learning even in areas where Chichewa is not the home language of the majority of pupils. Surveys indicate that generally parents feel that their children would be learning better if they started learning through English earlier than in Standard 5.
This study was conducted with a view to finding out whether English is the most appropriate language of learning for senior primary school children in Malawi. The study specifically addressed the question of whether or not the use of English as the language of learning in Social Studies resulted in better academic performance among Standard 7 pupils in Malawi. The study also addressed the question of whether the use of English as the language of learning increased pupil participation in the learning process and whether the use of Chichewa as the language of learning favoured Chichewa home language pupils more than Chiyao home language pupils.
The findings suggest that primary school children in Malawi are not linguistically prepared for instruction through the medium of English. Standard 7 pupils, the target of the study, found it difficult to learn Social Studies through English although they had had three years of English as the language of learing. Their participation in academic work was hampered by their limited mastery of the language.
Pre-test and post-test results show that Standard 7 pupils receiving instruction through Chichewa obtained higher scores than those who were taught in English. When Yao and Chewa children were taught together through the Chichewa medium, the Yao children scored as well as their counterparts whose home language was Chichewa. Thus the study suggests that the use of Chichewa benefited both groups while the use of English seemed to retard their performance. These results imply that the language policy in Malawi and the way teachers are currently trained to teach English in primary schools need to be re-examined and reviewed. / English Studies / D.Litt. et Phil. (English)
|
498 |
Moses son of Akhenaten? : a study of archaeology and textual perspectivesVine, Jayne Margaret 13 October 2015 (has links)
The search for a ‘historical Moses’ is one which has been debated for several centuries. In spite of copious archaeological finds in Egypt and other parts of the ancient Near East, no material remains have been found to substantiate the Exodus story. Mythological stories from the ancient Near East bear striking similarities to the Moses narrative found in the Hebrew Bible. The inconsistencies found in the Hebrew Bible further hamper the attempt to find a historical Moses, instead Moses is found only in tradition. Taking these issues into consideration, other possibilities need to be investigated. This dissertation places Moses growing up in the court of Akhenaten an 18th Dynasty Egyptian Pharaoh in the middle of the 14th century BCE. The study investigates the possibility of Moses as a son of Akhenaten with Nefertiti as a stepmother, his own biological mother, a Mitannian princess, having died giving birth to Moses. Several similarities between Akhenaten and Moses are discussed throughout the study. The study moves into the 21st century with the groundbreaking discovery of DNA, which provides new conclusions which before were only debated. / Biblical and Ancient Studies / M.A. (Biblical Archaeology)
|
499 |
Avaliação da reconstituição da função tímica e a caracterização das subpopulações de linfócitos T e do perfil de citocinas em pacientes submetidos ao transplante alogênico de células-tronco hematopoiéticas que desenvolveram doença do enxerto-contra-hospedeiro / Evaluation of thymic function recovery and characterization of T lymphocyte subpopulations and cytokines profile in patients underwent to allogeneic hematopoietic stem cell transplantation that developed graft-versus-host diseaseLuís Klaus Alves da Rocha 28 June 2018 (has links)
O transplante de células-tronco hematopoiéticas tem sido a melhor opção terapêutica para muitas doenças. Seu sucesso, no entanto, depende de alguns fatores que influenciam a taxa de mortalidade. A doença do enxerto-contra-hospedeiro é uma causa de mortalidade. Apresenta duas formas, a aguda e a crônica, e ambas têm linfócitos T na patofisiologia. Outra causa são as infecções, cujos patógenos variam conforme o tempo de recuperação do sistema imune. O presente estudo avaliou a recuperação linfoide T com base no timo e distinção das subpopulações e citocinas nos pacientes que desenvolveram doença do enxerto-contra-hospedeiro crônica no primeiro ano de transplante. Os pacientes foram alocados no Hospital de Transplante Amaral Carvalho (Jaú/SP) e tinham entre 18 e 60 anos de idade. No pré-transplante, foram comparados com indivíduos saudáveis, pareados em idade. Após o transplante, todos os pacientes foram acompanhados por um ano e seis meses, para observação de possíveis eventos de doença do enxerto-contra-hospedeiro e/ou infecções. A análise laboratorial foi feita com o sangue do paciente, sendo a primeira antes do transplante, seguidas por mais quatro, com intervalos de três meses. Tais avaliações laboratoriais tinham por objetivos caracterizar a função tímica por quantificação de sjTREC; as subpopulações de linfócitos T, por citometria de fluxo e a análise de citocinas, por Luminex. Foram estudados 172 indivíduos, sendo 75 do transplante alogênico, 43 do transplante autólogo, além de 54 pessoas saudáveis. Nossos resultados mostraram que os pacientes apresentaram função tímica diminuída antes mesmo da realização do transplante. A função tímica enfraquecida foi um fator de risco para doença do enxerto-contrahospedeiro crônica e a recuperação do sistema imune foi melhor nos pacientes que não apresentaram doença do enxerto-contra-hospedeiro crônica após um ano do transplante. No entanto, a função tímica não foi diferente entre os pacientes que faleceram e os que estão vivos. No geral, não houve distinção quanto à apresentação das subpopulações de linfócitos T e à produção de citocinas entre os pacientes submetidos ao transplante alogênico que desenvolveram doença do enxerto-contra-hospedeiro crônica, relativamente aos demais pacientes. Com o tempo, foi observada a recuperação gradual do compartimento linfoide T e diminuição na incidência de infecções. A taxa de infecções não influenciou a apresentação das subpopulações de linfócitos T e a produção de citocinas nos pacientes que desenvolveram doença do enxerto-contrahospedeiro crônica em relação aos demais pacientes. Como conclusão, a função tímica apresentou-se deteriorada antes da realização do transplante, porém não foi determinante para que houvesse piora na evolução clínica após o transplante. Os pacientes que desenvolveram doença do enxerto-contra-hospedeiro crônica, independentemente da incidência de infecções, apresentaram semelhança no perfil das subpopulações de linfócitos T e das citocinas, quando comparados aos demais / Hematopoietic stem cell transplantation has been the best therapeutic option for many diseases. Its success depends on some factors that influence the mortality rate. Graftversus- host disease is one cause of mortality. It has two forms, acute and chronic, and both have T lymphocytes in their pathophysiology. Other causes are infections, whose pathogens vary according to immune system recovery time. The present study evaluated the lymphoid T recuperation through the thymus and the differentiation of subpopulations and cytokines in patients who developed chronic graft-versus-host disease at the first year of transplantation. The patients were allocated at Hospital de Transplantes Amaral Carvalho (Jaú/SP). They were between 18 and 60 years old. At pre-transplant phase, patients were compared to healthy individuals, age-matched. After transplantation, they were all assisted for one year and six months, so that graft-versushost disease\'s and infections\' events could be observed. The laboratory analysis was done by blood sample; the first occurred before the transplant, followed by four more, every three months. Laboratory examinations were performed to characterize thymic function by quantification of sjTREC; T lymphocyte subpopulations, by flow cytometry, and cytokine analysis, by Luminex. A total of 172 individuals were studied: 75 allogeneic transplant patients, 43 autologous transplant patients and 54 healthy persons. Our results showed that patients presented thymic function impaired even before the transplant. The weakening of the thymic function was a risk factor for chronic graft-versus-host disease and immune system recovery was better in patients who did not develop chronic graft-versus-host disease after one year of transplantation. However, the thymic function was not different between patients who died and those who remained alive. In general, there was no distinction of the presentation of T lymphocyte subpopulations and cytokines production among patients who underwent allogeneic transplant and developed chronic graft-versus-host disease, in comparison to the other patients. Over time, a gradual recovery of the T lymphoid compartment and a decrease in the infections incidence were observed. The infection rate did not influence the presentation of the T lymphocyte subpopulations and the production of cytokines in patients who developed chronic graft-versus-host disease in comparison to the other patients. In conclusion, the thymic function was impaired before transplantation, but it was not relevant for clinical evolution worsening after transplantation. Patients who developed chronic graft-versus-host disease, regardless of the incidence of infections, showed similar profile of T lymphocytes subpopulations and cytokines, relatively to other patients
|
500 |
Die onontkombaarheid van die verlede (Afrikaans)Kemp, Anna Francina 22 February 2010 (has links)
AFRIKAANS : In die studie word gepoog om aan te dui op watter ingrypende maniere die Afrikaner se problematiese verlede altyd weer opduik in die hede, en op watter maniere hierdie verlede die groei en ontwikkeling van ’n nuwe Suid-Afrikaanse identiteit kan verhinder, of andersins, hoe ’n grondige en bewuste Auseinandersetzung met die verlede kan lei tot beter begrip, nie alleenlik van die verlede nie, maar ook van die hede en (ideaalgesproke) van die toekoms. Daar word geredeneer word dat ’n proses van bewuste konfrontasie met die verlede noodsaaklik is vir die ontwikkeling van ’n lewensvatbare identiteit. Hierdie proses sluit in ’n bewuswording en ontleding van die houdings van skuld (ook kollektiewe skuld), verlies en melancholie jeens die verlede. ’n Belangrike newe-komponent van die verhandeling is om hierdie proses te koppel aan verhaaltegniese middele wat aangewend word in die bundel vertellings onder bespreking. Daar word gepoog om ’n noodwendige verband te lê tussen tematiek en narratiewe tegnieke. In die verhandeling word aandag gegee aan die temas van skuld en verlies in die verhale, asook die vele motiewe wat gekoppel kan word aan hierdie twee temas. Daar word ook aandag gegee aan verteltegnieke soos tydsvorme, assosiatiewe skryfwyse, vertellingstrant en die stem van die verteller, wat aangewend word om die konfrontasie met en houdings jeens die verlede uit te beeld. Daar word geargumenteer in die verhandeling dat die prosa in hierdie bundel as vertellings gereken moet word, eerder as kortverhale (of meer spesifiek, short stories), en wel omdat die temas en die verteltegnieke bymekaar aansluit met die oog op ’n spesifieke leserrespons wat ’n grondige konfrontasie met en bestekopname van die verlede behels. ENLISH : The study focuses on the inescapable presence of a problematic past in contemporary South Africa, and the ways in which this past prevents the development of a new South African identity. It argues that a fundamental reckoning with the past will lead to a better understanding of the present and the future, and is essential to the development of a viable South African identity. This process of reckoning with the past involves an awareness and analysis of attitudes towards the past, which includes guilt (also collective guilt), loss and melancholy. The process of Auseinandersetzung with the past is then linked to specific narrative techniques which are employed in the collection of short prose under discussion. It is argued that there exists a connection between theme and narrative technique. Narrative techniques under discussion include tense (past and present tense), associative writing, narration and voice. It is argued that the short prose in the collection under discussion should be defined as (oral) narratives (vertellings), rather than Short Stories. The reader response towards an (oral) narrative differs from the response towards a Short Story, and the difference is essential in the process of confrontation with the problematic past/history. Copyright / Dissertation (MA)--University of Pretoria, 2010. / Afrikaans / unrestricted
|
Page generated in 0.0273 seconds