Spelling suggestions: "subject:"experimentation"" "subject:"xperimentation""
191 |
Analysis of and Role for Effector and Target Cell Structures in the Regulation of Virus Infections by Natural Killer Cells: a DissertationBrutkiewicz, Randy R. 01 September 1993 (has links)
The overall emphasis in this thesis is the study of the regulation of virus infections by natural killer (NK) cells. In initial analyses, vaccinia virus (VV)-infected cells were found to be more sensitive to NK cell-mediated lysis during a discrete period of time post-infection. This enhanced susceptibility to lysis correlated with enhanced triggering (but not binding) of the effector cells and a concomitant decrease in target cell H-2 class I antigen expression. Furthermore, VV-infected cells became resistant to lysis by allospecific cytotoxic T lymphocytes (CTL) at a time when they were very sensitive to killing by NK cells or VV-specific CTL. This suggested that alterations in class I MHC antigens may affect target cell sensitivity to lysis by NK cells.
The hypothesis that viral peptide charging of H-2 class I molecules can modulate target cell sensitivity to NK cell-mediated lysis was tested by treating target cells with synthetic viral peptides corresponding to the natural or minimal immunodominant epitopes defined for virus-specific CTL, and then target cell susceptibility to NK cell-mediated lysis was assessed. None of the 12 synthetic viral peptides used were able to significantly alter target cell lysis by NK cells under any of the conditions tested.
In order to determine if H-2 class I molecules were required in the regulation of a virus infection by NK cells in vivo, intact or NK depleted (treated with anti-asialo GM1 antiserum) β2-microglobulin-deficient [β2m (-/-)] mice, which possess a defect in H-2 class I antigen expression, were infected with the prototypic NK-sensitive virus, murine cytomegalovirus (MCMV). In anti-asialo GM1-treated β2m (-/-) mice, as well as in β2m + (H-2 class I normal) control mice also treated with anti-asialo GM1 a significant enhancement in splenic MCMV titers as compared to NK-intact animals, was observed. When thymocyte expression of H-2 class I molecules (H-2Db) in normal mice was analyzed, it was found that following MCMV infection, H-2Db expression was significantly greater than the low level of expression found in uninfected thymocytes. In marked contrast, thymocytes from β2m (-/-) mice did not display any detectable H-2Db before or after infection. These in vivoresults demonstrate that NK cells can regulate a virus infection, at least in the case of MCMV, independent of H-2 class I molecule expression.
Thymocytes from uninfected normal mice were found to be very sensitive to NK cell-mediated lysis, whereas those from MCMV-infected animals were completely resistant, presumably due to the protective effects of MCMV-induced interferon (IFN). However, thymocytes from MCMV-infected β2m (-/-) mice were only slightly protected from lysis by NK cells, consistent with the inverse correlation between MHC class I antigen expression and sensitivity to NK cell-mediated lysis. These results provide in vivoevidence suggesting a requirement for MHC class I molecules in IFN-mediated protection from lysis by NK cells.
In addition to the analysis of H-2 class I molecules on target cells, the identity of a molecule present on the surface of all NK cells and other cytotoxic effector cells, which is recognized by a monoclonal antibody (mAb) generated in this laboratory designated CZ-1, and can also modulate NK cell triggering, was also of interest. This laboratory has previously reported that this antigen is upregulated on cytotoxic (and other) lymphocytes following a virus infection in vivo, or upon activation in vitro. Using competitive FACS analysis and fibroblasts transfected with various isoforms of CD45, it was found that mAb CZ-1 recognizes a sialic acid-dependent epitope associated with a subpopulation of CD45RB molecules.
|
192 |
Biochemical Studies on the Hemolymph Trypsin Inhibitors of the Tobacco Hornworm Manduca Sexta: A ThesisRamesh, Narayanaswamy 01 March 1986 (has links)
Trypsin inhibitory activity from the hemolymph of the tobacco hornworm, Manduca sexta, was purified by affinity chromatography on immobilized trypsin and resolved into two fractions with molecular weights of 13700 (inhibitor A) and 8000 (inhibitor B) by Sephadex G-75 gel filtration. SDS-polyacrylamide gel electrophoresis under non-reducing conditions gave a molecular weight estimate of 15000 for inhibitor A and 8500 for inhibitor B. Electrophoresis of these inhibitors under reducing conditions on polyacrylamide gels gave molecular weight estimates of 8300 and 9100 for inhibitor A and inhibitor B, respectively, suggesting that inhibitor A is a dimer. Isoelectro-focusing on polyacrylamide gels focused inhibitor A as a single band with pI of 5.7, whereas inhibitor B was resolved into two components with pIs of 5.3 and 7.1. Both inhibitors A and B are stable at 100° C and at pH 1.0 for at least 30 minutes, but both are inactivated by dithiothreitol even at room temperature and non-denaturing conditions. Inhibitors A and B inhibit trypsin, chymotrypsin, plasmin, and thrombin but they do not inhibit elastase, papain, pepsin, subtilisin BPN' and thermolysin. In fact, subtilisin BPN' completely inactivated both inhibitors A and B. Inhibitor A and inhibitor B form stable complexes with trypsin. Stoichiometric studies showed that inhibitor A combines with trypsin and chymotrypsin in a 1:1 molar ratio. The inhibition constants (Ki) for trypsin and chymotrypsin inhibition by inhibitor A were estimated to be 1.45 x 10-8 M and 1.7 x 10-8M, respectively. Inhibitor A in complex with chymotrypsin does not inhibit trypsin (and vice versa) suggesting that inhibitor A has a common binding site for trypsin and chymotrypsin. The amino terminal amino acid sequences of inhibitors A and B revealed that both these inhibitors are homologous to the bovine pancreatic trypsin inhibitor (Kunitz) .
Quantitation of the trypsin inhibitory activity in the hemolymph of the larval and the pupal stages of Manduca sexta showed that the trypsin inhibitory activity decreased from larval to the pupal stage. Further, inhibitor A at the concentration tested caused approximately 50% reduction in the rate of proteolytic activation of prophenoloxidase in a hemocyte lysate preparation from Manduca sexta, suggesting that inhibitor A may be involved in the regulation of prophenoloxidase activation. However, inhibitor B was not effective even at three times the concentration of inhibitor A. Since activation of prophenoloxidase has been suggested to resemble the activation of alternative pathway of complement, the effect of inhibitors A and B and the hemolymph of Manduca sexta on human serum alternative pathway complement activity was evaluated. The results showed that, although inhibitors A and B do not affect human serum alternative complement pathway, other proteinaceous component(s) in Manduca sexta hemolymph interact(s) and cause(s) an inhibition of human serum alternative complement pathway when tested using rabbit erythrocyte hemolytic assay.
|
193 |
Neural Diversity in the Drosophila Olfactory Circuitry: A DissertationLai, Sen-Lin 31 July 2007 (has links)
Different neurons and glial cells in the Drosophila olfactory circuitry have distinct functions in olfaction. The mechanisms to generate most of diverse neurons and glial cells in the olfactory circuitry remain unclear due to the incomprehensive study of cell lineages. To facilitate the analyses of cell lineages and neural diversity, two independent binary transcription systems were introduced into Drosophila to drive two different transgenes in different cells. A technique called ‘dual-expression-control MARCM’ (mosaic analysis with a repressible cell marker) was created by incorporating a GAL80-suppresible transcription factor LexA::GAD (GAL4 activation domain) into the MARCM. This technique allows the induction of UAS- and lexAop- transgenes in different patterns among the GAL80-minus cells. Dual-expression-control MARCM with a ubiquitous driver tubP-LexA::GAD and various subtype-specific GAL4s which express in antennal lobe neurons (ALNs) allowed us to characterize diverse ALNs and their lineage relationships. Genetic studies showed that ALN cell fates are determined by spatial identities rooted in their precursor cells and temporal identities based on their birth timings within the lineage, and then finalized through cell-cell interactions mediated by Notch signaling. Glial cell lineage analyses by MARCM and dual-expression-control MARCM show that diverse post-embryonic born glial cells are lineage specified and independent of neuronal lineage. Specified glial lineages expand their glial population by symmetrical division and do not further diversify glial cells. Construction of a GAL4-insensitive transcription factor LexA::VP16 (VP16 acidic activation domain) allows the independent induction of lexAop transgenes in the entire mushroom body (MB) and labeling of individual MB neurons by MARCM in the same organism. A computer algorithm is developed to perform morphometric analysis to assist the study of MB neuron diversity.
|
194 |
Development of Pharmacological Magnetic Resonance Imaging Methods and their Application to the Investigation of Antipsychotic Drugs: a DissertationSchmidt, Karl F. 08 July 2006 (has links)
Pharmacological magnetic resonance imaging (phMRI) is the use of functional MRI techniques to elucidate the effects that psychotropic drugs have on neural activity within the brain; it is an emerging field of research that holds great potential for the investigation of drugs that act on the central nervous system by revealing the changes in neural activity that mediate observable changes in behavior, cognition, and perception. However, the realization of this potential is hampered by several unanswered questions: Are the MRI measurements reliable surrogates of changing neural activity in the presence of pharmacological agents? Is it relevant to investigate psychiatric phenomena such as reward or anxiolysis in anesthetized, rather than conscious animals? What are the methods that yield reproducible and meaningful results from phMRI experiments, and are they consistent in the investigations of different drugs?
The research presented herein addresses many of these questions with the specific aims of
1) Developing pharmacological MRI methodologies that can be used in the conscious animal,
2) Validating these methodologies with the investigation of a non-stimulant, psychoactive compound, and
3) Applying these methodologies to the investigation of typical and atypical antipsychotic drugs, classes of compounds with unknown mechanisms of therapeutic action
Building on recent developments in the field of functional MRI research, we developed new techniques that enable the investigator to measure localized changes in metabolism commensurate with changing neural activity. We tested the hypothesis that metabolic changes are a more reliable surrogate of changes in neural activity in response to a cocaine challenge, than changes observed in the blood-oxygen-level-dependent (BOLD) signal alone. We developed a system capable of multi-modal imaging in the conscious rat, and we tested the hypothesis that the conscious brain exhibits a markedly different response to systemic morphine challenge than the anesthetized brain. We identified and elucidated several fundamental limitations of the imaging and analysis protocols used in phMRI investigations, and developed new tools that enable the investigator to avoid common pitfalls. Finally, we applied these phMRI techniques to the investigation of neuroleptic compounds by asking the question: does treatment with typical or atypical antipsychotic drugs modulate the systems in the brain which are direct or indirect (i.e. downstream) substrates for a dopaminergic agonist?
The execution of this research has generated several new tools for the neuroscience and drug discovery communities that can be used in neuropsychiatric investigations into the action of psychotropic drugs, while the results of this research provide evidence that supports several answers to the questions that currently limit the utility of phMRI investigations. Specifically, we observed that metabolic change can be measured to resolve discrepancies between anomalous BOLD signal changes and underlying changes in neural activity in the case of systemically administered cocaine. We found clear differences in the response to systemically administered morphine between conscious and anesthetized rats, and observed that only conscious animals exhibit a phMRI response that can be explained by the pharmacodynamics of morphine and corroborated by behavioral observations. We identified fundamental and drug-dependent limitations in the protocols used to perform phMRI investigations, and designed tools and alternate methods to facilitate protocol development.
By applying these techniques to the investigation of neuroleptic compounds, we have gained a new perspective of the alterations in dopaminergic signaling induced by treatment with antipsychotic medications, and have found effects in many nuclei outside of the pathways that act as direct substrates for dopamine. A clearer picture of how neuroleptics alter the intercommunication of brain nuclei would be an invaluable resource for the classification of investigational antipsychotic drugs, and would provide the basis for future studies that examine the neuroplastic changes that confer therapeutic efficacy following chronic treatment with antipsychotic medications.
|
195 |
In Vitro and in vivo Studies of Murine Polytropic Retrovirus Infections: a DissertationLoiler, Scott A. 01 September 2000 (has links)
Murine leukemia viruses (MuLV) are retroviruses that play important roles in the study of oncogenes, integration, transcriptional regulation and gene therapy. Mink cell focus-inducing (MCF) viruses are polytropic MuLVs that by definition infect cells from a wide variety of species. Their ability to infect human cells and their utility as gene therapy vectors were not well characterized. To address this issue, primary and immortalized human cells were tested for their ability to be infected by MCF packaged defective vectors as well as replication competent MCF virus. A new packaging cell line, called MPAC, was created to package defective retroviral vectors in virus particles with envelope proteins derived from a Moloney mink cell focus-inducing (Mo-MCF) virus. The cellular tropism of MPAC-packaged retroviral vectors was the same as replication competent MCF viruses. Testing various established cell lines showed some human cell lines could be infected with MPAC-packaged vectors while others cannot. In addition, I show that some human cells fully support MCF virus replication while others either partially or fully restrict MCF virus replication. This indicates that some human cells express a protein on their surface that acts as a receptor for MCF viruses and allows MCF viral entry. In addition, the human cells that express a receptor for MCF viral entry did not show any further block to viral replication.
An important determinant in the pathogenic phenotype of MCF 247 has been mapped to the enhancer region of the retroviral long terminal repeat (LTR). Recombination of endogenous genetic elements with the 3' portion of envoccurs and incorporates unique LTR sequences. Most strongly pathogenic MCF viruses have a duplication of the enhancer element found in the LTR.
AKR mice are an inbred strain of mice that develop spontaneous T-cell lymphomas between 6 and 12 months of age. 12-25 % of MCF induced early lymphomas of AKR mice show MCF viral integration's near c-myc in an opposite transcriptional orientation. A replication competent MCF virus containing a bacterial amber suppressor tRNA gene (supF) was used to investigate the changes in the enhancer region following injection of MCF containing one enhancer in the LTR. Newborn AKR mice were injected with the supF tagged replication competent virus and observed for signs of leukemia development (ruffled fur, lethargy, and tumor development). When these signs were detected, the animals were sacrificed and DNA was prepared from the isolated tumors. Thirty-one tumors DNA were analyzed for the presence of supF tagged virus and rearrangement of the c-myc locus. Nine supF tagged proviral LTRs integrated near c-myc from four animals were PCR amplified, sequenced, and/or cloned. All of the enhancer elements analyzed were derived from proviruses that integrated in a reverse orientation with respect to c-myc locus. Two of the isolated enhancer elements contained only a few base changes whereas the majority contained duplications of different sizes that encompassed different transcription factor binding sites. The duplicated enhancer regions contained duplications from 82-134 bp in length. One tumor contained a proviral enhancer with only 5 bp changes relative to the injected virus. This suggests that the enhancers need only a few specific base changes relative to the injected virus to accelerate leukemogenesis. The other three tumors contained proviral enhancers with various size duplications and additional transcription factor binding sites. These data suggest that the injected virus is not pathogenic unless the enhancer region is altered. One proviral integration site encompassing a duplicated enhancer region and 139 bp of the c-myc gene locus was PCR amplified, cloned and sequenced. A search of the current transcription factor database (Transfac 3.3) showed no known transcription factor binding site sequences were created at the junction of the enhancer duplications. The common motif of LVb, core NF-1, and GRE transcription factor binding sites, described by Golemis at al (57), was conserved throughout the isolated enhancers. Most of the enhancer elements contained additional NF-кB and/or GRE sites in close proximity to the conserved LVb-core region. These results support the hypothesis that additional NF-кB and/or GRE binding sites cooperatively interact with the conserved GRE-NF-1-LVb-core motif in c-myc induced leukemogenesis. In addition, two unique families of enhancer duplications were identified. The two families contained enhancers isolated from different tumors that displayed sequence homology and transcription factor binding site organization unique to each group.
|
196 |
Orientace v čase v mateřské škole se zaměřením na Slunce a Měsíc / Time orientation at kindegarten focused on the sun and the moonHavlíková, Jana January 2018 (has links)
TITLE: Orientation in time at kindergarten focusing on the Sun and Moon AUTHOR: Bc. Jana Havlíková DEPARTMENT: SUPERVISOR: PhDr. Micheala Kaslová ABSTRACT: This diploma thesis deals with the development of orientation in time focusing on the Sun and Moon in preschool children as part of the attendance at kindergarten. In the theoretical part, in addition to the definition of the term of time from various disciplines, there is also an outline of the development of perception and measurement of time in terms of both evolutionary and individual development. Many activities in kindergartens are preserved for a long time, however the observation of the sky itself has slowly disappeared from education programs and plans. The practical part is focused on setting up scenarios of individual activities for observing the position of the sun in the sky, the length and direction of the sun's shadow, and the awareness of the alternation of the day with the night and the seasons. All this within the framework of action research, which was implemented in one kindergarten class. KEYWORDS: pre-mathematical literacy, preschool education, pre-school age, time, orientation in time, sun, shadow, universe, day and night
|
197 |
Étude mécanique et microstructurale des sols bio-cimentés : application aux ouvrages hydrauliques en terre / Mechanical and microstructural study of biocemented soils : application to hydraulic earthworks.Dadda, Abdelali 07 December 2017 (has links)
Le procédé de bio-cimentation est une technique prometteuse pour renforcer les sols lâches et de faible résistance mécanique. Cette technique a montré une très bonne efficacité pour plusieurs types de sols lors d’essais en laboratoire, dans des modèles physiques ou lors d’essais sur site. Par contre, elle a montré une forte sensibilité aux conditions de traitement telles que concentrations des réactifs, bactéries, vitesse d’injection, type de sols, température, etc… Ces facteurs influencent principalement la distribution spatiale de la calcite précipitée, sa forme et sa morphologie, ce qui influence par la suite les propriétés effectives des sols traités. Ces travaux de thèse ont été réalisés dans le cadre du projet BOREAL qui vise à renforcer par cette technique des digues et barrages en terre existants contre l’érosion interne des noyaux et la liquéfaction des fondations. L'objectif de cette thèse est d'étudier l’évolution des propriétés physiques et mécaniques du sable bio-cimenté (perméabilité, résistance mécanique) par la réalisation d’essais mécaniques et de mesures de perméabilité en laboratoire, et de lier cette évolution aux changements microstructuraux via des observations par microtomographie RX. Le travail a commencé par des essais de bio-cimentation de colonnes de sable de Fontainebleau afin de vérifier la faisabilité de la bio-cimentation en laboratoire. Suite à ces essais de faisabilité, des essais triaxiaux drainés ont été réalisés sur le sable bio-cimenté afin d’estimer l’évolution de ses paramètres de résistance tels que la cohésion et l'angle de frottement. Des petits volumes de sable bio-cimenté présentant différentes teneurs en calcite ont été extraits des échantillons triaxiaux et observés par micro-tomographie aux rayons-X à l’ESRF sous une très haute résolution (0,65 µm/ pixel). Des méthodes quantitatives d’imagerie 3D ont été développées pour calculer les propriétés microstructurales moyennes (quantité de calcite, porosité, surface spécifique et surface spécifique de calcite) et les propriétés de contact (surface de contact, nombre de coordination, type de contacts, orientation des contacts, etc…) pour les différents échantillons observés. Cette étude a montré une forte évolution de la résistance du sable bio-cimenté (évolution non-linéaire de la cohésion, évolution quasi-linéaire de l’angle de frottement, légère augmentation de la résistance résiduelle, etc…) et une diminution de la perméabilité par la précipitation de la calcite à l’intérieur de l’échantillon. L’étude quantitative de l’évolution de la microstructure a montré une stabilité de la surface spécifique de la calcite à partir d’un certain niveau de calcification, une forte évolution quasi-linéaire de la surface de contact cohésive entre les grains ainsi qu’une légère évolution du nombre de coordination par la création de nouveaux contacts. La comparaison de ces évolutions avec celles obtenues pour un arrangement périodique de type cubique simple en utilisant deux scenarii de précipitation (uniforme et localisée au niveau du contact) a montré que la précipitation de la calcite se produit principalement dans les zones de contact inter-granulaire. L’utilisation de ces informations microstructurales dans des modèles micromécaniques a permis d’estimer avec succès les propriétés effectives du sable bio-cimenté (cohésion, perméabilité, modules élastiques). Enfin, les mêmes outils ont été utilisés pour étudier la durabilité chimique du sable bio-cimenté. Cette étude a montré une dégradation de la résistance du sable par la dissolution de la calcite à l’intérieur des échantillons. Les mesures quantitatives sur les images 3D ont montré une dégradation de la surface de contact sans hystérésis par rapport à l’évolution de ces surfaces de contacts pendant le processus de bio-cimentation. / The biocementation process is considered as a promising technique for strengthening loose and weak soils. This technique has shown very good efficiency for several types of soil through laboratory tests and large scale models. On the other hand, it has shown a high sensitivity to the treatment conditions such as reactant concentrations, bacteria, injection rate, type of soil, temperature, etc…. These factors influence mainly the spatial distribution of the precipitated calcite, its shape and morphology, which subsequently influences the effective properties of the treated soils. This thesis is part of the French research project BOREAL, which aims at reinforcing old dykes and earth dams with this technique against internal erosion of the core and liquefaction of foundations. The objective of this thesis is to study the evolution of the physical and mechanical properties of biocemented sands (permeability, mechanical strength) by performing mechanical tests and permeability measurements in the laboratory and linking this evolution to microstructural changes by using quantitative 3D X-ray imaging tools. To do this, this work began with biocementation tests on Fontainebleau sand to verify the feasibility of the biocementation process in the laboratory. After these feasibility tests, drained triaxial tests have been carried out on the biocemented sand in order to estimate the evolution of its resistance parameters such as cohesion and friction angle. Small sub-samples of biocemented sand with different calcite contents have been then extracted and observed using X-ray micro-tomography at ESRF at a very high resolution (0.65 μm / pixel). Quantitative methods of 3D imaging have been developed to compute mean microstructural properties (amount of calcite, porosity, specific surface area and specific surface area of calcite) and contact properties (contact surface area, coordination number, type of contacts, contact orientation, etc…) for the different observed sub-samples. This study has shown a strong evolution of the resistance of biocemented sand (non-linear evolution of the cohesion, quasi-linear evolution of the friction angle, a slight increase of the residual resistance, etc...) and a decrease of the permeability by the precipitation of the calcite inside the sample. The quantitative study of the evolution of the microstructure has shown a stability of the specific surface area of the calcite beyond a certain level of calcification, a strong quasi-linear evolution of the cohesive contact surface between the grains as well as a slight evolution the coordination number (creation of new contacts). The comparison of these evolutions with those obtained considering a simple cubic periodic arrangement using two precipitation scenarii (uniform and localized at the contact) has shown that the precipitation of the calcite mainly occurs in the zones of inter-granular contact. This microstructural information have4 been then used successfully in micromechanical models to estimate the effective properties of biocemented sand (cohesion, permeability, elastic moduli). Finally, the same tools have been used to study the chemical durability of biocemented sand. This study has shown a degradation of sand resistance by dissolving calcite within the samples. The quantitative measurements on the 3D images have shown a degradation of the contact surface area without hysteresis with respect to the evolution of these contact surfaces during the biocementation process.
|
198 |
Contribution of Ordered Water Molecules and a Crucial Phenylalanine to Cooperative Pathway(s) in Scapharca Dimeric Hemoglobin: a DissertationPardanani, Animesh Dev 01 June 1997 (has links)
The homodimeric hemoglobin (HbI) from the blood clam Scapharca inaequivalvis binds oxygen cooperatively and thus offers a simple model system for studying communication between two chemically identical sites. Although the individual subunits of HbI have the same myoglobin-fold as mammalian hemoglobins, the quaternary assemblage is radically different. Upon oxygen binding by HbI, only small tertiary changes are seen at the subunit interface in contrast to the relatively large quaternary changes observed with mammalian hemoglobins. Analysis of structures of this hemoglobin in the liganded (02or CO) and unliganded states has provided a framework for understanding the role of individual amino acid side-chains in mediating cooperativity. The work presented in this dissertation has directly tested the central tenets of the proposed structural mechanism for cooperativity in HbI, illuminating the key roles played by residue Phe 97 and interface water molecules in intersubunit communication.
Heterologous expression of Scapharca dimeric hemoglobin: A synthetic gene has been utilized to express recombinant RbI in Escherichia coli. The HbI apoprotein constitutes 5-10% of the total bacterial protein in this system. Addition of the heme precursor δ-aminolevulinic acid to the expression culture results in a ~3-fold increase in the production of soluble hemoglobin. Recombinant HbI has been successfully purified to homogeneity, resulting in a final yield of 80-100 mg of pure holoprotein from a 12 L expression culture. Analysis of recombinant HbI reveals its oxygen binding properties to be indistinguishable from native HbI. It was necessary to correct a protein sequence error by mutating residue Asn 56 to aspartate in order to obtain diffraction quality crystals, that are isomorphous to native HbI crystals. These recombinant HbI crystals diffract to high resolution, permitting the functional effects of mutant HbI proteins to be correlated with detailed structural analysis.
|
199 |
Resisitir, problematizar e experimentar como desdobramentos do aprenderKreutz, José Ricardo January 2009 (has links)
Esta tese é um estudo sobre três possíveis signos desdobrados pelos díspares do aprender, que são: (1) Resistência; (2) Ideias-Problema; (3) Experimentações. A investigação teórica e empírica, gerada pelos registros do diário de anotações, é narrada pelo personagem conceitual intitulado filosofeiro, que busca perscrutar os processos de individuação de tais signos no aprender que acontece no grupo de estudos de professores inserido no Projeto CIVITAS (Cidades Virtuais: Tecnologias de Aprendizagem e Simulação - LELIC/PPGEdu/UFRGS). O desdobramento dos signos do aprender se disparatam nos contextos (1) Político de referência; (2) Ético de imanência e (3) Estético de composição. Como metodologia, o estudo lança mão de uma perspectiva cartográfica do grupo de estudos de professores, o qual tem, como consigna, o uso do diário de anotações, a partir do qual é feita uma análise dos desdobramentos do aprender no processo de formação de professores em serviço. O estudo em questão também procura fazer uma discussão da articulação entre os signos no programa de experimentação promovido pelas regras do CIVITAS. O texto está estruturado a partir de uma apresentação do problema e da metodologia de investigação, situando o contexto do município de Sobradinho/RS/Brasil, cidade onde a experimentação com os professores foi realizada. Estabelece, também, uma relação entre essa experimentação e as políticas públicas de formação de professores. O plano político apresenta o signo resistência no contexto da experimentação, fazendo tensão aos modos de referência da ordem do mundo que influenciam a formação de professores e reforçando o modo indivíduo na educação. O plano da ética propõe que o signo idéia-problema exige uma nova forma de pensar, designada de eclusamento, pelo qual as faculdades do pensamento não concordam para o mesmo objeto, sugerindo que essa violência do pensamento gera problematizações no exercício cotidiano do aprender. Finalmente, o plano da estética ocupa-se com o contexto das composições, no qual o filosofeiro apresenta o signo da experimentação e algumas histórias de cidades inventadas em sala de aula junto com as crianças do projeto CIVITAS. Nesse contexto, onde o aprender se desdobra no signo da experimentação, evidencia-se a necessidade de aprender na saturação da composição. / This thesis is a study of three possible signs deployed by disparate learning, which are: (1) Endurance, (2) Problem-Ideas, (3) Experiments. Both theoretical and empirical records generated by daily notes, are narrated by the conceptual character named philosophist who seeks to scrutinize the process of individuation of such signs in learning that happens in the study group of teachers in the CIVITAS Project (Virtual Cities: Learning and Simulation Technologies - LELIC / PPGEDU / UFRGS). The development of learning signs makes little sense in the following contexts (1) Reference policy (2) Ethics of immanence and (3) Composition aesthetic. As a methodology, the study makes use of a cartographic perspective of the study group of teachers, which has, as noted, the use of daily notes, from which it examines the developments of the learning process in teacher education in service. This study also seeks to make a discussion of the relationship between the signs in the experimental program sponsored by the rules of CIVITAS. The text is structured around a problem statement and research methodology, setting the context of the town of Sobradinho / RS / Brazil, where the experiment with the teachers was held. In addition, it establishes a relationship between this experiment and the public policies of teacher education. The policy plan shows the sign of Endurance in the context of the experiment, causing tension on the reference modes of the world order that influence teacher education and improving the individual way in education. The ethical plan proposes the idea that the sign-problem requires a new way of thinking, so called locks, by which the faculties of thought do not agree over the same object, suggesting that the violence of thought generates problematizations on daily learning exercises. Finally, the aesthetics plane is concerned with the context of compositions in which the philosophist presents the sign of the experiment and some invented town stories in the classroom with children of the CIVITAS project. In this context, where learning unfolds in the sign of the experiment, the need to learn the saturation of the composition is highlighted.
|
200 |
A experimentação nos cursos de licenciatura em química na modalidade a distânciaPonticelli, Fernanda Alves January 2015 (has links)
A carência de professores da educação básica em diferentes áreas das escolas públicas do Brasil tem fomentado o desenvolvimento de diversas políticas públicas de incentivo a formação de professores por meio da educação a distância. Tendo como base dados estatísticos do Instituto Nacional de Estudos e Pesquisas Educacionais Anísio Teixeira e da Associação Brasileira de Educação a Distância dos últimos 13 anos observou-se a grande necessidade de formação de professores da educação básica que ministram a disciplina de Química nas regiões Norte, Nordeste e Centro-oeste do Brasil. A presente pesquisa teve como objetivo compreender como a experimentação ocorre nos cursos de Licenciatura em Química, de instituições públicas, ofertados na modalidade a distância nas referidas regiões. A construção do corpus se deu por meio da investigação dos Projetos Pedagógicos dos cursos localizados nas regiões citadas e entrevistas com os coordenadores dos referidos cursos, e a interpretação do corpus de análise teve como base a Análise Textual Discursiva, à luz dos referenciais teóricos de experimentação (GALIAZZI, 2000; GONÇALVES, 2005; HODSON, 1994; ROSITO, 2000; GIORDAN, 1999; ZUCOLOTTO, 2010) e das legislações vigentes. Os resultados indicam que as atividades práticas são realizadas nos polos de apoio presencial ou na sede da Instituição de Ensino Superior, tendo como base roteiros pré-determinados e sob a coordenação dos professores ou tutores; ainda, os relatórios provenientes das atividades práticas são utilizadas para compor a média final do aluno. Contudo, foi possível constatar, por parte dos coordenadores, a necessidade da problematização das referidas atividades práticas, na formação de professores, para a sua adaptação a real necessidade das escolas de educação básica públicas do Brasil. / The lack of basic education teachers in different areas of public schools in Brazil has fostered the development of several public policies to encourage the training of teachers through distance education. Based on statistical data from the National Institute of Educational Studies Teixeira and the Brazilian Association of Distance Education of the last 13 years there was a great need for basic education teacher training to teach the discipline of Chemistry in the North, Northeast and Midwest of Brazil. This research aimed to understand how the trial occurs in Chemistry Degree courses, public institutions, offered in the distance in these regions. The construction of the corpus was through the investigation of the pedagogical projects of the courses located in the mentioned regions and interviews with the coordinators of these courses, and the interpretation of the corpus of analysis was based on the Textual Analysis Discourse in light of theoretical experimentation reference (Galiazzi, 2000; Gonçalves, 2005; HODSON, 1994; ROSITO, 2000; GIORDAN, 1999; Zucolotto, 2010) and current legislation. The results indicate that practical activities are held at the poles on-site support or the headquarters of the Higher Education Institution, with the predetermined routes basis and under the supervision of teachers or tutors; Moreover, reports from the practical activities are used to compose the final average student. However, it was established, by the coordinators, the necessity of questioning of such practical activities, teacher training, to adapt the real need of public basic education schools in Brazil.
|
Page generated in 0.098 seconds