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Sousa, Eduardo Henrique Viana de. "Obten??o e caracteriza??o de nanolubrificantes utilizados em refrigera??o aditivados com nanoparticulas de ?ndio (In)." PROGRAMA DE P?S-GRADUA??O EM ENGENHARIA MEC?NICA, 2017. https://repositorio.ufrn.br/jspui/handle/123456789/23647.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
A crescente demanda por produtos com maior performance, menor custo de fabrica??o, menos impactantes ao meio ambiente que sejam mais eficientes energeticamente, t?m fomentado pesquisas em diversas ?reas da nanoci?ncia e nanotecnologia (N&N), visando sobrepujar estas limita??es ou agregando as principais vantagens dos nanocomp?sitos e nanofluidos (NF) os quais tem sido extensivamente aplicados nas ind?strias. O objetivo deste trabalho foi estudar as caracter?sticas de nanolubrificantes (NL) aditivado com nanopart?culas (NPs) de ?ndio (In), para poder contribuir com a redu??o significativa do tamanho, peso e custos dos sistemas de transfer?ncia de calor, tendo estes uma melhor estabilidade mec?nica, uma menor resist?ncia ao atrito e desgaste, e que possuia uma melhor ader?ncia em regime de lubrifica??o limite. Para estes fins, ap?s a aquisi??o das NPs de In, foram preparados tr?s nanolubrificantes (NLs) distintos, adicionando-se 0,3 g/L aos ?leos de compressores de refrigera??o herm?ticos o ISO68, ISO32, e o Poliol ?ster (POE). Ap?s o processo de prepara??o que consiste na desfragmenta??o e homogeneiza??o, cada composto foi ensaiado em banho termost?tico e com o aux?lio de um re?metro e um condutiv?metro, foi mensurados os valores relativos ?s suas propriedades t?rmicas, para comprovar as propriedades requisitadas. A estabilidade mec?nica foi verificada atrav?s de compara??es cronol?gicas, potencial zeta e aglomera??o de part?culas, ap?s passou-se por ensaios de lubricidade utilizando-se os trib?metos de sonda com movimento alternado em alta frequ?ncia (High Frequency Reciprocating Rig ? HFRR) e ensaio de pino contra disco para an?lise de desempenho tribol?gico. Os corpos de prova dos ensaios foram analisados em MEV (Microscopia eletr?nica de varredura) e EDS (Espectr?metro de Dispers?o de Energia) para comprova??o dos resultados, onde foram realizadas analises dos modelos desenvolvidos, levando em considera??o par?metros como: coeficiente de fric??o, for?a de atrito, desgaste etetivo, composi??o final dos corpos de prova a aglomera??o das part?culas nos NLs, a temperatura e a viscosidade do fluido, e movimento Browniano das part?culas, entre outros. Os NLs compostos por In foram vi?veis, n?o se fazendo necess?ria a utiliza??o de tensoativos para melhorar a sua estabilidade, pois apresentaram resultados satisfat?rios nos ensaios tribol?gicos, mostrando-se com propriedades de lubrificantes de extrema press?o (EP), melhorando significativamente o desempenho tribol?gico. Assim, torna-se vi?vel a utiliza??o NLs gerados a partir de NP de In na lubrifica??o de compressores herm?ticos de refrigera??o.
The increasing demand for products with higher performance, lower manufacturing cost, less impactful to the environment and are more energy efficient, have fostered research in various areas of nanoscience and nanotechnology (N&N), aiming at overcoming these limitations or adding the main advantages of nanocomposites and nanofluids (NF) which have been extensively applied in industries. The objective of this work was to study the characteristics of nano-lubricants (NL) added with nanoparticles (NPs) of indium (In), In order to contribute to the significant reduction of the size, weight and costs of heat transfer systems, which have a better mechanical stability, a lower resistance to friction and wear, and a better adhesion in the limit lubrication regime. For these purposes, after the acquisition of In NPs, three separate nanolubrificantes (NLs) were prepared, adding 0.3 g / L to hermetic refrigeration compressor oils ISO68, ISO32, and Polyol Ester (POE). After the preparation process consisting of defragmentation and homogenization, each compound was tested in a thermostatic bath and with the aid of a rheometer and a conductivity meter, where the values relative to their thermal properties are measured, to verify the required properties. The mechanical stability was verified through chronological comparisons, Zeta potential and particle agglomeration, after being subjected to lubricity tests using probe tribromes with High Frequency Reciprocating Rig ? HFRR and pin-to-disk test for tribological performance analysis. The test specimens were analyzed in SEM (Scanning Electron Microscopy) and EDS (Energy Scattering Spectrometer) to prove the results, where analyzes of the developed models were carried out, taking into account parameters such as: Friction coefficient, friction force, wear resistance, final composition of the test specimens as well as the agglomeration of the particles in the NLs, temperature and viscosity of the fluid, and Brownian motion of the particles, among others. The NLs comprised of In were feasible, with the use of surfactants not being necessary to improve the stabilities, presented satisfactory results in the tribological tests, showing with properties of extreme pressure lubricants (EP), significantly improving the tribological performance. Thus, it becomes feasible to use NLs generated from NP of In in the lubrication of hermetic refrigeration compressors.
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Khadrah, S. "NNS/NNS interaction during task-based synchronous computer-mediated communication." Thesis, University of Manchester, 2007. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.508026.
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Bezerra, Paulo Cesar Rego, and Jose Bittencourt de 1937 Andrade. "Sistemas de referencia associados ao NNSS." reponame:Repositório Institucional da UFPR, 2013. http://hdl.handle.net/1884/32062.
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Resumo: O proposito deste trabalho e discutir os conceitos relacionados a definicao e a materializacao dos sistemas de referencia associados ao Navy Navigation Satellite System (NNSS). Sao apresentados todos os principios teoricos necessarios ao completo entendimento desta questao, de um modo tal que eles sao facilmente aplicaveis a outros sitemas de satelites de posicionamento ou de navegacao.
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Iwashita, Noriko. "Comprehensible output in NNS-NNS interaction in Japanese as a foreign language." Connect to thesis, 1993. http://repository.unimelb.edu.au/10187/1523.
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This study is a partial replication of Pica et al’s study (1989) of comprehensible output, and investigates comprehensible output in NNS-NNS interaction in Japanese as a Foreign Language. Data were collected using two different types of tasks (information gap and jigsaw tasks) in three sub-groups of different proficiency levels (High-High, Low-Low, and High-Low) in order to find out (1) to what extent the tasks provide opportunities for learners to modify their initial output in response to requests for clarification and confirmation, and (2) the extent to which learners actually modify their output in response to interlocutor requests.The results show that comprehensible output is an important phenomenon in NNS-NNS interaction. Unlike the result of Pica et al, task types had more effect on opportunities for comprehensible output and actual production of comprehensible output than request types. Not much difference was found among different proficiency groups.
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Manley, Lucy B. "Embedding the Consultant: A NNES Case Study." Miami University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1407853148.
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Simmers, Jessica L. "nNos localization, muscle function and atrophy in skeletal muscle disorders." Thesis, The Johns Hopkins University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3573097.
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In skeletal muscle, loss of neuronal nitric oxide synthase (nNOS) from the sarcolemma has been observed in a few muscular dystrophies and myopathies. However, the extent of this phenomenon, its mechanism, and its physiological impact are not well understood. Using immunofluorescent staining for nNOS, a survey of 161 patient biopsies found absent or reduced sarcolemmal nNOS in 43% of patients. Patient mobility and muscle functional status correlated with nNOS mislocalization from the sarcolemma. Mouse models of inherited and acquired myopathies showed similar loss of sarcolemmal nNOS and impaired mobility and muscle function. A proteomic approach, using mass spectrometry and differentially labeled control and steroid-induced myopathy (SIM) mouse samples, found novel nNOS binding proteins including alpha-actinin-3 (ACTN3), which exhibited decreased interaction with nNOS after steroid treatment. It revealed a potential explanation for impaired muscle function in SIM as nNOS interactions were lost at the sarcomere and gained at the sarcoplasmic reticulum impairing contractility. Treating nNOS-deficient mice with steroids demonstrated that loss of sarcolemmal nNOS reduces muscle contractility and strength in SIM through increased nitric oxide (NO) signaling. In SIM mice treated with a nitric oxide donor and steroids, nitric oxide partially protects the muscle from atrophy and improves muscle fatigability and recovery suggesting nNOS mislocalization also decreases NO availability. These findings show that loss of sarcolemmal nNOS is a common phenomenon that negatively impacts muscle function. Therapeutic strategies targeting nNOS or NO signaling need to allow for the complexity of local nitric oxide content and cellular context.
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Heidler, Linda E. "NNS Use of Adverbs in Academic Writing." Thesis, University of North Texas, 2011. https://digital.library.unt.edu/ark:/67531/metadc84213/.
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Recent studies have begun to redefine the idea of accuracy in second language acquisition to include not only grammatical correctness, but also native-like selection. This is an exploratory study aimed at identifying areas of nonnative-like selection of adverbs, such as sentence position, semantic category preferences, frequency of use and breadth of word choice. Using corpus-linguistic methods it compares the writing of nonnative English speakers at an intermediate and advanced level to both American college students’ writing and published academic writing. It also conducts in-depth case studies of three of the most commonly used adverbs. It finds that while advanced students are grammatically accurate, there are still several ways in which their use of adverbs differs from that of native speakers.
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Quick, Zoe Louise. "The Effects of Prenatal Exposure to Methadone on Clinical and Neurobehavioural Outcomes of Infants Measured at Term." Thesis, University of Canterbury. Psychology, 2006. http://hdl.handle.net/10092/1365.
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This study examined the effects of prenatal exposure to methadone on clinical and neurobehavioural outcomes of infants between 40 and 42 weeks gestation. The aims of this study were: (a) to describe clinical and neurobehavioural outcomes of infants exposed to methadone during pregnancy, (b) to examine the effects of maternal methadone dose during pregnancy on infant clinical and neurobehavioural measures, and (c) to examine the extent to which associations between exposure to methadone during pregnancy and infant outcomes persisted after statistical control for a range of confounding variables. Two groups of study infants were recruited. These consisted of 51 consecutively recruited infants born to mothers maintained on methadone during their pregnancy and 42 randomly identified non-methadone exposed comparison infants. Prior to her child's birth, each pregnant woman completed a comprehensive maternal interview. At birth and during the infant's hospital stay a broad perinatal data-base was collected. At 42 weeks gestation infants underwent a neurobehavioural assessment including the NICU Network Neurobehavioural Scale (NNNS; Lester & Tronick, 2004) and infant cry analysis. Study results showed significant differences across several clinical and neurobehavioural measures. Infants exposed to methadone in utero were found to be significantly lighter, have smaller head circumferences, and spend longer in hospital. Neurobehaviourally, they were significantly less well regulated, less attentive, more easily aroused, more excitable, and more hypertonic. In addition, they exhibited less motor maturity, displayed more stress abstinence symptomatology, and required more support from the assessor in order to remain in an appropriate state. Concurrent analysis of infant cry characteristics revealed no significant differences between the fundamental frequencies or the melody contours of the two groups. However, infants prenatally exposed to methadone did display higher levels of frequency perturbation in their cries, as evidenced by analysis of their jitter factor and percentage of directional jitter. Analysis of the effects of maternal dose during pregnancy suggested that maternal dose levels above 60mg/day were general indicative of poorer infant outcomes than those below 60mg/day, with significant linear trends occurring across a number of measures. The extent to which associations between methadone exposure during pregnancy and infant outcomes reflected either a) the direct effects of methadone exposure and/or b) the effects of confounding factors correlated with maternal methadone use was examined using regression analysis. The results of this analysis for infant clinical outcomes showed confounding variables attenuated the effects of methadone exposure on infant birth length and, to some degree, infant head circumference. In contrast, associations between methadone exposure during pregnancy and most neurobehavioural outcomes remained significant, suggesting that maternal methadone use during pregnancy is an important, independent predictor of infant neurobehavioural functioning. These findings support the view that prenatal exposure to methadone has at least short term impacts on the infant's central nervous system (CNS) development. Important implications of possible vulnerabilities faced by these infants and their families are discussed.
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Cheung, Nathan Yiutung. "Serotonin receptor and neuronal nitric oxide synthase expression in the rat brain : implications for MDMA toxicity." Thesis, King's College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368095.
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Penlington, Roger. "Operational characteristics of the NNPB plunger in the glass container industry." Thesis, Sheffield Hallam University, 1994. http://shura.shu.ac.uk/20218/.
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Although glass containers are an everyday item the process responsible for their production is not scientifically understood. Developments have occurred slowly over many years, mostly on a trial and error basis and in response to economic pressures. The narrow neck press and blow (NNPB) process has evolved in recent years as a result of attempts to reduce container weight. The fundamental component of the NNPB process is the plunger which is responsible for the initiation of the cavity and control of glass distribution within the container. The NNPB plunger functions as a form tool and as a heat exchanger, thus requiring a carefully selected range of properties. The Engineer responsible for tooling selection and operation has a limited resource of scientific knowledge to enable the performance of the process to be optimised. The current NNPB plunger is subject to high rates of wear and is directly responsible for product defects, thermal instability and limits process speed. The work presented here is a scientific study of current NNPB plunger technology. The plunger has been investigated in relation to the requirements of the glass container forming process. The materials used have been examined, before and after use and their wear modes explained. The thermal properties of the plunger have, as far as is possible, been examined during the forming cycle. When combined with results from the characterisation of transformations occurring in the material, during its service life, operational requirements have been explained. The ability of the NNPB plunger to remove heat from the glass has been investigated, and has illustrated significant deficiencies in the current arrangement. Details are given as to how these deficiencies may be overcome to enable the Engineer to regain control of the process. As a result of the study many phenomena exhibited by the NNPB plunger are now understood and may be related to the performance of the process.
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Jähne, Sebastian [Verfasser]. "Kompensationsmechanismen im Skelettmuskel von neuronaler Stickstoffmonoxid-Synthase (nNOS) defizienten Mäusen / Sebastian Jähne." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2010. http://d-nb.info/1027814905/34.
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Lim, Gregory B. S. "nNOS-derived nitric oxide modulation of the ryanodine receptor calcium release channel." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533867.
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Sato, Vinicius Antonio Hiroaki. "Participação da serotonina no efeito tipo-antidepressivo induzido pela inibição da nNOS no hipocampo de ratos." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/17/17133/tde-22062011-090727/.
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Introdução: O óxido nítrico (NO) tem sido relacionado como um importante neuromodulador envolvido com a neurobiologia da adaptação ao estresse e da depressão. De fato, a administração sistêmica ou intra-hipocampal de inibidores da NO sintase neuronial (nNOS) induz efeitos do tipo antidepressivo em modelos animais. Evidências recentes indicam que os efeitos sistêmicos dos inibidores da nNOS são dependentes dos níveis de serotonina no encéfalo. O sistema serotoninérgico do hipocampo dorsal, por ativação dos receptores serotoninérgicos do tipo 1A (5HT1A), facilita a adaptação ao estresse e contribui para os efeitos comportamentais de drogas antidepressivas. Portanto, o objetivo do presente estudo foi testar a hipótese de que o efeito do tipo antidepressivo induzido pela administração hipocampal de inibidores da nNOS seria mediado pela facilitação da neurotransmissão serotoninérgica local e subseqüente ativação de 5HT1A. Métodos: Após cirurgia estereotáxica, ratos Wistar com cânulas-guia direcionadas ao hipocampo dorsal foram submetidos a sessão de pré-teste (PT 15 minutos de nado) e receberam administrações locais das drogas: N-propil-L-arginina (NPA, inibidor seletivo da nNOS: 0,00001 - 1 nmol/0,5 µL), fluoxetina (SSRI: 1, 3 e 10 nmol/0,5 µL), WAY100635 (antagonista seletivo para 5HT1A: 1, 3 e 10 nmol/0,5 µL) ou veículo (0,5 µL). 24h depois, o tempo de imobilidade foi registrado em uma sessão de 5 minutos de nado. Todos os protocolos foram aprovados por um comitê de ética local (Proc. No 08.1.1133.53.4) Resultados: A administração intra hipocampal de NPA ou fluoxetina reduziu significativamente o tempo de imobilidade em animais submetidos ao teste do nado forçado, um efeito tipo antidepressivo. A administração de WAY100635 não induziu efeito por si, mas foi capaz de bloquear os efeitos induzidos por fluoxetina ou NPA. Conclusões: A inibição da nNOS, pelo NPA, ou a inibição da recaptação de serotonina, pela fluoxetina, no DH induziu efeito do tipo antidepressivo de similar magnitude. O fato de que o pré-tratamento com WAY100635 foi capaz de bloquear os efeitos induzidos por NPA e fluoxetina indica que ambos os efeitos são mediados por facilitação da neurotransmissão serotoninérgica local e subseqüente ativação de 5HT1A. Assim, esses resultados sugerem que níveis aumentados de NO no DH poderiam levar a um déficit na neurotransmissão serotoninérgica local e, portanto, predispor ao desenvolvimento das conseqüências comportamentais do estresse.Introduction: Nitric oxide (NO) has been suggested to play an important role in the neurobiology of stress adaptation and depression. In fact, systemic or hippocampal administration of neuronal NO synthase (nNOS) inhibitors induces antidepressant-like effects in animal models. Recent evidence indicates that the systemic effects of nNOS inhibitors are dependent on serotonin levels in the brain. The serotonergic system of the dorsal hippocampus (DH), through the activation of serotonin 1A (5-HT1A) receptors, is proposed to mediate stress adaptation and the behavioral effects of antidepressant drugs. Therefore, the aim of the present study was to test the hypothesis that the antidepressant-like effects induced by nNOS inhibition into the hippocampus would be mediated by a facilitation of the local serotonergic neurotransmission and subsequent 5-HT1A receptor activation. Methods: Male Wistar rats with guide-cannulae aimed at the DH were submitted to the pretest session (PT - 15 minutes of swimming) and received local administrations of the drugs: n-propyl-L-arginine (NPA, selective nNOS inhibitor: 0.00001 - 1 nmol/0.5 µL), fluoxetine (SSRI: 1, 3 and 10 nmol/0.5 µL), WAY100635 (selective 5-HT1A antagonist: 1, 3 and 10 nmol/0.5 µL) or vehicle (0.5 µL). One day later, the immobility time was registered at a 5 minutes swimming test session. All protocols were approved by a local ethical committee (Proc. N. 08.1.1133.53.4.) Results: The intrahippocampal administration of NPA or fluoxetine reduced the immobility time in animals submitted to the forced swimming test, an antidepressant-like effect in this model. WAY100635 did not induce any effect per se, but it was able to block the effects induced by fluoxetine or NPA. Conclusions: Inhibition of nNOS, by NPA, or inhibition of serotonin reuptake, by fluoxetine, in the DH induced antidepressant-like effects of similar magnitude. The fact that pretreatment with WAY100635 was able to block NPA- and fluoxetine-induced effects indicates that both effects are mediated by a facilitation of the local serotonergic neurotransmission and subsequent activation of 5-HT1A receptors. Therefore, these results suggest that increased NO levels in the DH could impair local serotonergic neurotransmission and, thus, predisposes to the development of stress-induced behavioral consequences, such as depressive-like behaviors.
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Sicola, Laura. "No, they won't "just sound like each other" NNS-NNS negotiated interaction and attention to phonological form on targeted L2 pronunciation tasks." Frankfurt, M. Berlin Bern Bruxelles New York, NY Oxford Wien Lang, 2009. http://d-nb.info/991032276/04.
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Sato, Vinicius Antonio Hiroaki. "Substratos neurais envolvidos com o desenvolvimento do comportamento de desamparo em ratos: possível envolvimento do NO." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/17/17133/tde-20072016-091556/.
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Recentemente, o óxido nítrico (NO) tem sido relacionado com a depressão. A administração de inibidores da NO sintase (NOS) induz efeitos do tipo antidepressivo em modelos animais e há um aumento da expressão da NOS em estruturas do sistema límbico em indivíduos depressivos e em animais expostos a estresse. Além disso, sabe-se que o estresse causa um aumento da ativação de neurônios localizados em estruturas do sistema límbico e que o tratamento com antidepressivos bem como com inibidor da NOS, diminui essa marcação. Contudo, ainda não se sabe como o sistema nitrérgico dessas estruturas está relacionado com os comportamentos relacionados à depressão. Assim nosso objetivo é testar a hipótese de que o desenvolvimento do desamparo (comportamento relacionado à depressão) em ratos seria causado por um aumento de atividade de neurônios que contém nNOS em estruturas envolvidas com a resposta emocional ao estresse, e que os diferentes tratamentos induzem efeitos do tipo antidepressivo no modelo apresentando através de um efeito final comum de diminuir essa ativação e, portanto, diminuir os níveis de NO. Para isso, ratos foram submetidos ao modelo do desamparo aprendido e tratados com drogas antidepressivas. Após o teste, foi feita a imunohistoquímica com marcação para Fos (Fos-IR; marcador de atividade neuronal) e nNOS (nNOS-IR). O tratamento repetido com desipramina (DES, na dose de 25, mas não na de 12,5 mg/Kg), fluoxetina (FXT, na dose de 15, mas não na de 30 mg/Kg) e imipramina (IMI, 15mg/Kg) induziu efeito do tipo-antidepressivo no teste do desamparo aprendido (LH). O tratamento agudo apenas com imipramina, mas não com FXT ou IMI, induziu o mesmo tipo de efeito. O tratamento com DES, FXT ou IMI também aumentou o número de cruzamentos entre choques no LH, porém não induziu aumento de atividade locomotora no teste do campo aberto. O tratamento repetido com DES diminuiu a Fos-IR na amígdala basolateral (BlAm), amígdala lateral (LAm), córtex pré-frontal medial (mPFC), região CA1 e CA3 do hipocampo dorsal (dHPC) e região CA3 do hipocampo ventral (vHPC). O tratamento agudo com DES induziu um aumento de Fos-IR na amígdala central (CeAm), amígdala medial (MeAm) e CA1 e CA3 do dHPC. O tratamento repetido com FXT diminuiu Fos-IR na BlAm e LAm, enquanto o tratamento agudo aumentou Fos-IR na CeAm. O tratamento repetido com IMI aumentou nNOS-IR na MeAm e a dupla marcação no núcleo leito da estria terminal (BST); e diminuiu o Fos-IR na região CA1 do dHPC e na região parvocelular do núcleo paraventricular do hipotálamo (pPVN). Por fim, foram encontradas relações positivas entre o número de células Fos-IR e o número de falhas em fugir ou escapar dos choques no LH na BlAm, LAm, CA1 e CA3 do dHPC e CA3 do vHPC; i.e., quanto mais células ativadas nessas estruturas, maior o número de choques que os animais receberam sem consegui fugir. Os resultados aqui apresentados são, em parte, corroborados pela literatura, mostrando a participação das estruturas analisadas no comportamento do desamparo aprendido e no efeito das drogas antidepressivas. Nesse contexto, acredita-se que o BST funcionaria como um núcleo de processamento da informação vinda do mPFC, HPC e amígdala, enviando projeções para o PVN e regulando o funcionamento do eixo HPA. O trabalho abre caminho para a identificação de subpopulações específicas de neurônios que expressam a nNOS, buscando compreender o papel destas na modulação das respostas comportamentais numa situação de estresse, na busca pela formulação de um cenário cada vez mais completo da participação do sistema nitrérgico dentro do complexo neurocircuito que regula as emoçõesRecently, nitric oxide (NO) has been related with the neurobiology of depression. The NO synthase (NOS) inhibition induces antidepressant-like effects in animal models and there is an increase in the NOS expression in limbic structures of depressed patients or in stress exposed animals. Besides, it is well known that stressful events causes an increase in limbic structures neuronal activation and that antidepressant treatment as well as NOS inhibition attenuates this effect. However, it is still unknown how the limbic nitrergic system is related with depression-related behaviors. Then, the aim of this work is to test the hypothesis that the helplessness behavior development (a depression-related behavior) in rats would be induced by an increased activity of nNOS-containing neurons in structures related with the neurobiology of stress responses. Furthermore, the antidepressant-like effect induced by antidepressants treatment in this model would share a final effect, decreasing the activation of such neurons, and decreasing the levels of NO in these structures. For this aim, male rats were submitted to the learned helplessness model and treated with antidepressants. After the test, immunohistochemistry assay were performed, with double labeling for c-Fos (Fos-IR; neuronal activity marker) and nNOS (nNOS-IR). The repeated treatment with desipramine (DES, 25 mg/kg but not 12,5mg/kg), fluoxetine (FXT, 15 mg/Kg, but not 30 mg/Kg) and imipramina (IMI, 15 mg/KG) induced antidepressant-like effects in the learned helplessness test (LH). The acute treatment with IMI, but not with DES or FXT, induced the same effect. The repeated treatment with DES, FXT or IMI also increased the number of intertrial crossings in the LH, but not the locomotor activity score on the open field score. The repeated treatment with DES decreased the number of Fos-IR into the basolateral amygdala (BlAm), lateral amygdala (Lam), medial prefrontal cortex (mPFC), CA1 and CA3 regions of the dorsal hippocampus (dHPC), and CA3 region of the ventral hippocampus (vHPC). The acute treatment with DES increased the Fos-IR into the central amygdale (CeAm), medial amygdala (MeAm), and CA1 and CA3 regions of the dHPC. The repeated treatment with FXT decreases the number of Fos-IR into the BlAm and Lam, while the acute treatment increases the Fos-IR into the CeAm. The repeated treatment with IMI increased the nNOS-IR into the MeAm and the double- labeled cells into the bed nucleus of stria terminalis (BST); and decreased the Fos-IR into the CA1 region of the dHPC and into the parvocellular region of the paraventricular nucleus of the hypothalamus. Finally, positive correlations between the number of Fos-IR and the number of failures in escaping or avoiding the foot shocks on the LH were found into the BlAm, Lam, CA1 and CA3 of the dHPC, and CA3 of the vHPC, i.e., with more activated cells into these structures mentioned, more foot shocks the rats received. These results are (partially) corroborated with previous scientific papers, showing the analyzed structures participation in the learned helplessness behavior as well as in the antidepressant effect of antidepressant administration. Within this context, the BST would work as a relay center, processing the information coming from the mPFC, HPC and amygdaloid nuclei, and sending the output to the PVN, modulating the HPA axis. This work open some questions about the identification of specific nNOS-containing neuronal subpopulations, aiming to clarify their role in the stress response, and searching for the formulation of a more complete scenario of the nitrergic system participation in this complex emotion-regulating neurocircuit
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McNamara, Tanner. "ENOS and nNOS contribution to reflex cutaneous vasodilation during dynamic exercise in humans." Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/13788.
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Master of ScienceDepartment of Kinesiology
B.J. Wong
Recent data suggests nNOS mediates the NO-component of reflex cutaneous vasodilation with passive heat stress. Our hypothesis was nNOS, but not eNOS, inhibition would attenuate reflex cutaneous vasodilation during dynamic exercise. Protocol 1: subjects performed a VO[subscript]2 peak test on a supine cycle ergometer. Protocol 2: with experimental arm at heart level subjects cycled in supine posture at 60% VO[subscript]2 peak to raise core temperature (Tc) 0.8-1.0°C (35-45 min). In protocol 2 subjects were equipped with 4 microdialysis fibers on the forearm and each randomly assigned as: 1) lactated Ringer’s (control); 2) 5mM NPLA (nNOS inhibition); 3) 10mM L-NIO (eNOS inhibition); and 4) 20mM L-NAME (non- selective NOS inhibition). At the end of protocol 2 all sites were locally heated to 43°C and infused with SNP to elicit maximal dilation. Mean arterial pressure (MAP), skin blood flow via laser- Doppler flowmetry (LDF), and Tc via ingestible telemetric pill were measured; cutaneous vascular conductance (CVC) was calculated as LDF/MAP and normalized to maximum. In protocol 2 there was no significant difference between control (62±5 %CVCmax) and NPLA (61±6 %CVCmax). L-NIO (38±4 %CVCmax) and L-NAME (41±7 %CVCmax) significantly attenuated CVC compared to control and NPLA (p<0.001 all conditions). There was no difference between L-NIO and L- NAME. We conclude eNOS, not nNOS, contributes to reflex cutaneous vasodilation during dynamic exercise.
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Sangüesa, Ferrer Juan F. "Modulation fonctionnelle et distribution du canal calcique Cav3. 2 : rôle de la nNOS." Montpellier 1, 2008. http://www.theses.fr/2008MON1T015.
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Le canal calcique Cav3. 2 joue un rôle capital dans de nombreux processus physiologiques, notamment dans la transmission de la douleur aigüe et chronique. Cependant, les mécanismes régulant la distribution et les propriétés de ces canaux restent encore mal connus. Au cours de ma thèse, j'ai participé au développement d'un nouveau modèle pour étudier ces mécanismes : la souris knock-in Cav3. 2-GFPécliptique. Cette souris permettra d'étudier la localisation et la dynamique de Cav3. 2 in vivo grâce à une étiquette fluorescente insérée dans la partie extracellulaire du canal. Des sites de recombinaison loxP ont été également introduits dans le génome de cette souris afin d'effectuer des invalidations tissu-spécifiques et/ou inductibles du canal. En parallèle, une approche protéomique m'a permis d'identifier un nouveau partenaire de Cav3. 2 : la nNOS, une enzyme responsable de la production d'oxyde nitrique (NO). En effet, nous avons montré que Cav3. 2 possède un motif très conservé dans sa région C-terminale qui lui permet d'interagir avec le domaine de PDZ de la nNOS. Cette interaction a des conséquences fonctionnelles pour les deux protéines. D'une part, la présence de la nNOS induit une diminution de la densité des courants générés par le canal Cav3. 2, grâce à un mécanisme qui nécessite l'activité de l'enzyme et la présence d'un centre coordinateur d'ions métalliques dans la partie extracellulaire du canal. D'autre part, nous avons montré que Cav3. 2 est capable de modifier la distribution subcellulaire de la nNOS. L'enzyme est emmenée par le canal à proximité de la membrane plasmique où elle est plus facilement activée par l'entrée de calcium. Cette association fonctionnelle Cav3. 2-nNOS pourrait être impliquée dans des processus comme la nociception, la mémoire et la régulation du tonus vasculaire.
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Lu, Chieh-Ju. "Neuronal nitric oxide synthase-CAPON regulation of cardiac sympathetic activity in the development of hypertension." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:1204dec9-9f09-458d-b361-c8d14589fcd1.
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The studies presented in this thesis were undertaken to investigate the cellular and molecular mechanisms responsible for sympathetic hyperactivity that is observed in the Spontaneous Hypertensive Rat (SHR) and whether these abnormalities arise even before the onset of hypertension. Moreover, selected molecular candidates related to oxidative state in cardiac autonomic signalling have been explored for their potential therapeutic effects. Chapter One is an overview of (i) the relevance of autonomic dysfunction in cardiovascular disease in both human and animal models, (ii) the physiological basis of cardiac sympathetic neurotransmission, (iii) the neuromodulators of peripheral cardiac sympathetic-vagal balance discussed along with how they may be involved in cardiac adrenergic control of neurotransmission and NO-cGMP signalling. This develops the formulation of the specific aims of the thesis. Chapter Two outlines a detailed rationale for the experimental approach taken to (i) characterise protein expression in the pre-hypertensive animal model with immunohistochemistry and Western blotting, (ii) manipulate selected gene expression to amplify NO-cGMP signalling in vivo and in vitro via viral gene transfer, (iii) investigate calcium handling in cardiac sympathetic stellate neurons with calcium imaging , (iv) measure cardiac noradrenergic neurotransmission from double atria using radioactive-labelled [3H]-noradrenaline. Chapter Three demonstrated abnormal NO-cGMP signalling in pre-hypertensive SHRs. Endogenous nNOS protein residing in both cardiac parasympathetic and sympathetic neurons was significantly lower in the pre-hypertensive SHR compared to aged-matched WKYs. This was associated with lower cGMP levels. An enhanced depolarization evoked [Ca2+]i transient was observed in cardiac stellate neurons from pre-hypertensive SHR when compared with the WKY, an effect that was reversed by nNOS or sGC inhibition. Chapter Four investigated the role of nNOS and brain natriuretic peptide (BNP) in cGMP signalling pathways. Gene transfer of nNOS via adenoviral vector in SHR cardiac sympathetic neurons increased cGMP concentration and normalised neuronal calcium handling during depolarization. BNP significantly reduces [3H]- noradrenaline release. Overexpression of PDE2 which facilitates the breakdown of cGMP caused an increase in [3H]- noradrenaline release in response to field stimulation and also prevented the inhibitory action of BNP. Chapter Five examined the role of the nNOS adaptor protein, CAPON in NO-cGMP signalling. Endogenous CAPON protein is present in cardiac sympathetic neurons in the WKY, and is significantly reduced in pre-hypertensive SHR cardiac neurons. Artificial up-regulation of cardiac sympathetic CAPON via targeted gene transfer directly attenuated neuronal Ca2+ transients, resulting in decreased noradrenaline release in the SHR. Chapter Six is a concluding discussion summarising the main findings from this thesis, placing them in a physiological context and discussing avenues for further research.
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Santos, Jaqueline Rocha Borges dos. "Participação da enzima nNOS na sensibilização cruzada entre estresse e etanol em camundongos Swiss." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/42/42136/tde-15032014-084536/.
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O objetivo deste trabalho foi investigar alterações comportamentais produzidas por etanol (ET) e estresse crônico imprevisível (ECI) em camundongos adolescentes (ADL) e adultos (AD), estudando a participação da enzima nNOS. Em camundongos AD também estudamos a atividade da nNOS via receptor NMDA na sensibilização cruzada entre estresse por imobilização (EI) e ET, utilizando dizocilpina (DZP) como pré-tratamento. Os resultados demonstraram haver sensibilização cruzada entre ECI e ET, tanto nos ADL quanto nos AD. Houve aumento da atividade da nNOS em hipocampo (HP) e córtex frontal (CF) de AD submetidos ao ECI. ET atenuou este efeito. A sensibilização cruzada em ADL aumentou atividade da nNOS em CF. O pré-tratamento com 7-nitroindazol inibiu sensibilização cruzada entre ECI e ET em ADL e AD, sinalizando a participação da nNOS. DZP potencializou sensibilização cruzada entre EI e ET e diminuiu a atividade da nNOS em HP e CF de animais submetidos ao EI. ECI e EI induzem sensibilização comportamental ao ET e nNOS participa na sensibilização cruzada entre ECI/EI e ET.The objective of this work was to investigate behavioral alterations produced by ethanol (ET) and chronic unpredictable stress (CUS) in adolescent (ADL) and adult (AD) mice, studying the nNOS enzyme activity. In AD mice was also studied the nNOS activity through the NMDA receptor in the cross-sensitization between immobilization stress (IS) and ET, by using dizocilpine (DZP) as a pretreatment. The results demonstrate cross-sensitization between CUS and ET in the ADL and AD mice. There was an increase in the nNOS activity in hippocampus (HP) and frontal cortex (FC) of AD submitted to CUS. This effect was attenuated by ET. The cross-sensitization in ADL increased the nNOS activity in FC. The 7-nitroindazole pretreatment inhibit cross-sensitization between CUS and ET in ADL and AD, signaling the nNOS participation. DZP potentiates cross-sensitization between IS and ET and decreased the nNOS activity in HP and FC of animals submitted to IS. CUS and IS induce behavioral sensitization to the ET and nNOS participate in the cross-sensitization between CUS/IS and ET.
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Kegler, Melissa Jean. "NES and NNES reactions to in- and out-group usages of dyke and fag /." Abstract, 2009. http://eprints.ccsu.edu/secure/00000564/01/2004ABSTR.htm.
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Thesis (M.S.) -- Central Connecticut State University, 2009.Thesis advisor: Matthew Ciscel. "... in partial fulfillment of the requirements for the degree of Master of Science in Teaching English to Speakers of Other Languages." Includes bibliographical references (leaves 62-63). Abstract available via the World Wide Web.
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Do-Thi, Nga. "Etude théorique de la fragmentation des petits agrégats neutres de carbone Cn et des hydrocarbures CnH." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00651020.
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Ce travail de thèse porte sur l'étude théorique de la fragmentation de petits agrégats carbonés et d'hydrocarbures neutres par le modèle statistique Micarocanonical Metropolis Monte Carlo (MMMC). Ce modèle décrit, à contrainte d'énergie fixée, l'espace des phases associé à tous les degrés de liberté accessibles au système (partitions des masses, mouvements de translation et de rotation, spin et moment angulaire des fragments, etc.). Les ingrédients de base du modèle (énergies de dissociation, géométries, fréquences de vibration etc.) doivent être obtenus par un calcul ab initio. Ils ont été calculés à l'aide de la théorie de la fonctionnelle de la densité (DFT) au niveau de calcul B3LYP/6-311+G(3df). Les probabilités obtenues des voies de fragmentation en fonction de l'énergie d'excitation, ont été comparées aux données expérimentales obtenues auprès du Tandem. Des faisceaux de haute vitesse (projectile de Cn+ à v = 2.6 u.a. et de CnH+ à v = 4.5 u.a.) entraient en interaction avec les noyaux d'hélium. Tous les rapports de branchement des voies de fragmentation des Cn (n ≤ 9) et des CnH (n ≤ 4) résultant de capture électroniques ont été mesurés. La distribution d'énergie d'excitation de l'agrégat parent a du être ajustée pour que les mesures expérimentales soient reproduites d'une façon optimale, à l'aide de deux algorithmes : Non-Negative Least Squares et backtracing Bayesien. La comparaison des probabilités théoriques et expérimentales montre un bon accord global. Les deux algorithmes de minimisation ont convergé vers des distributions d'énergie déposée présentant des pics. Ces pics pourraient être la signature d'états moléculaires spécifiques jouant un rôle dans la fragmentation du cluster.
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Molza, Anne-Elisabeth. "Etude in silico du complexe impliquant le domaine central de la Dystrophine, le domaine PDZ de la nNOS, l'Actine filamenteuse et les Phospholipides membranaires." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1B018.
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La dystrophine est une très grande protéine codée le gène DMD et située sous la membrane plasmique des fibres musculaires. Elle joue un rôle essentiel dans le maintien de l’intégrité de la cellule musculaire lors des cycles de contraction/relaxation. Cette protéine filamenteuse est composée de quatre domaines structuraux dont le domaine central composé de 24 répétitions homologues à la spectrine. Chaque répétition est organisée en faisceau de trois α-hélices appelé « coiled-coil ». Des mutations du gène DMD sont à l’origine des myopathies de Duchenne (DMD) et de Becker (BMD) qui s’accompagnent d’un déficit total ou d’une dystrophine mutée et induisent de ruptures fréquentes de la membrane des cellules musculaires. La connaissance de la structure de la dystrophine est nécessaire au développement de thérapies à ce jour inexistantes pour les myopathies. Au laboratoire, des données structurales du domaine central de la dystrophine ont été acquises par diffusion des rayons X aux petits angles (SAXS, Small Angles X-ray Scattering). Cette thèse présente le développement d’une approche multi-échelle combinant des données expérimentales SAXS et des données in silico pour la reconstruction de modèles haute-résolution des fragments du domaine central de la dystrophine et d’un fragment muté observé dans une mutation BMD fréquente. Nous avons également cartographié l’interaction de ce domaine central avec deux de ses partenaires fonctionnels importants, l’actine filamenteuse et avec la nitroxyde synthase neuronale (nNOS) et proposé les premiers modèles atomiques des complexes macromoléculaires correspondants. L’ensemble de ces résultats permettra à terme l’optimisation de thérapies pour le traitement des dystrophies musculairesDystrophin is a large protein encoded by DMD gene and located under the plasma membrane of muscle fibers. It plays an essential role in maintaining the integrity of muscle cells during contraction/relaxation cycles. This filamentous protein is composed of four structural domains including the central domain consisting of 24 spectrin-like repeats and four hinges. Each repetition is folded in three α-helices in a ‘coiled-coil’ assembly. Mutations in the DMD gene leads to Duchenne muscular dystrophy (DMD) and Becker (MDBs), which are accompanied by frequent plasma membrane ruptures, due to the loss or modification of dystrophin protein. There are very few structural data available concerning the central domain of dystrophin, which is subject to many mutations involved in DMD and BMD diseases. However, the description and the understanding to an atomic level of dystrophin structure and its interaction is essential for optimization of therapies. Given the impossibility to solve its structure by X-ray crystallography or NMR, structural data of the dystrophin central domain were acquired by small angles X-rays scattering (SAXS, Small Angles X-ray Scattering). This thesis presents the development of an innovative multi-scale approach combining experimental SAXS and in silico derived data, allowing the reconstruction of high-resolution models of dystrophin central domain fragments. Structural data were also obtained on a mutated dystrophin frequently observed in BMDs. Furthermore, we also mapped the interactions of the central domain with two of its majors functional partners, Filamentous actin and neuronal nitroxyde synthase (nNOS) and proposed models of the related macromolecular complexes. At long-term, all of these results will allow optimization of therapies for the treatment of muscular dystrophies
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Given, Alexis. "Models of Epsilon-Sarcoglycan Gene Inactivation and their Implications for the Pathology of Myoclonus Dystonia." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/23790.
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Myoclonus Dystonia (MD) is an autosomal dominant movement disorder characterized by bilateral myoclonic jerks paired with dystonia 1. Mutations have been mapped to the ε-sarcoglycan (SGCE) gene in about 40% of patients 2,92. The purpose of this project was to examine the properties of SGCE in the central nervous system (CNS) and use this knowledge to elucidate the pathology of MD. Although Sgce is a member of the sarcoglycan complex (SGC) in other tissues, little is known about its interactions in the CNS. The vast majority of mutations in SGCE alter the translational reading frame. Proteins arising from these rare mutations are less stable than the wild type (WT) and undergo preferential degradation via the ubiquitin proteasome system 3. As this locus is maternally imprinted, patients with MD are effectively null for sgce expression 73,91. Therefore, Sgce knock out (KO) models should approximate MD conditions both in vivo and in vitro.
As there are no current treatments for MD, in sight into the pathology of the disease will aid in eventual treatments and help bring patients some relief by finally understanding their disease. Since a large percentage of MD patients are without the sgce protein, identifying what this protein’s function is and how its absence effects normal processing in the brain should help to identify the underlying cellular pathology which produces the MD phenotype.
This research was performed under the hypothesis that, in neuronal cells, sgce interacts with a group of proteins that together play a role in stabilization and localization of ion channels and signaling proteins at the cell membrane. The aims were to: (1) Build a MD mouse model with either a conditional knock-out (cKO) or a conditional gene repair (cGR) mutation; (2) Use neuroblastoma cells to identify the other proteins which interact with sgce in neurons, and; (3) Determine if there is a disruption of the localization of the sgce-complex members due to the loss of sgce.
Recombineering was used to complete the constructs for two transgenic mouse models: One model for the KO of exon 4 of sgce and one for the cGR in intron 1. Primary neurosphere lines from two previously generated chimeras were developed, as well as from a WT mouse. These neurosphere cell lines allowed comparisons of RT-PCR results from a heterogeneous neurological cell population to neuroblastoma cell lines.
mRNA is present in neuronal cells for many of the DGC associated proteins. It was confirmed that the KD of sgce results in a reduction of nNOS protein and in increased proliferation of NIE cells. By using a nitrite/nitrate assay as well as studies with L-NAME, it was confirmed that this increased proliferation was in fact due to a lack of nNOS function. These proliferation changes did not occur in N2A cells, which do not express high levels of nNOS during proliferation, further confirming nNOS’s role in the proliferation changes. Using qRT-PCR, KD of sgce was shown to result in significant changes in the transcript levels for many DGC associated proteins. This suggests that a DGC-like complex is forming in neuronal cells. Also, as a result of difficulties with the research, it became clear that over-expression of sgce causes cell death. This observation was quantified using cell counts and TUNEL staining, both showing significant results.
Additionally, several new constructs were created which will hopefully be of use for future students wanting to study sgce’s functions. New shRNA targeting sgce and sgcb have been made and both constructs result in reducing the expression of sgce. Seven different flag-tagged sgces have been created and some of these have been transferred into a tet-inducible system, which should circumvent the problem of over-expression. Finally GFP-tagged constructs for sgce and sgcb have been made and pooled clones have been developed. These tools will hopefully enable future students to continue to tease apart sgce’s function(s).
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Eisenhauer, Astrid. "Die kognitiven Defizite in einem Sepsismodell bei Ratten sind auf eine Herunterregulierung der nNOS zurückzuführen." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=970030274.
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Lewis, Sophronia. "The effect of ablation and acute inhibition of plasma membrane calcium ATPase 4 (PMCA4) with a novel inhibitor on isolated mouse mesenteric resistance arterial contractility." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/the-effect-of-ablation-and-acute-inhibition-of-plasma-membrane-calcium-atpase-4-pmca4-with-a-novel-inhibitor-on-isolated-mouse-mesenteric-resistance-arterial-contractility(676a26ea-867e-4947-9544-76b356fce23a).html.
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Plasma membrane calcium ATPase 4 (PMCA4) is a calcium extrusion pump which may also modulate Ca2+-triggered signal transduction pathways. Previous studies postulate that PMCA4 modulates signalling via an interaction with neuronal nitric oxide synthase (nNOS) in localised plasmalemmal microdomains. The effect of PMCA4 on vascular contractility is unclear. This project has utilised PMCA4 ablated mice (PMCA4 KO (-/-)) and a novel specific PMCA4 inhibitor (termed AP2) to study the role of PMCA4 in mouse resistance artery contractility.Immunohistochemistry, Western blotting and polymerase chain reaction (PCR) confirmed the absence of PMCA4 in the brain, vasculature and ear snips obtained from PMCA4 KO (-/-) mice whereas it was present in those from wild type (WT (+/+)) mice. Pressure myography was employed to assesss contractile function of isolated, pressurised (to 60 mmHg) mesenteric resistance arteries from 3 months old male PMCA4 KO (-/-) and WT (+/+) mice, in response to high K+ physiological salt solution (KPSS) (40mM & 100mM) and noradrenaline (NA) (Log[NA] -9.0 to -5.0M). Passive lumen diameter and left and right wall thicknesses of arteries from PMAC4 KO (-/-) and WT (+/+) mice were taken at transmural pressures of 5-140 mmHg. Effects of acute PMCA4 inhibition with AP2 (10µM and 1µM), nitric oxide synthase (NOS) inhibition with LNNA (100µM) and specific nNOS inhibition with Vinyl-L-Nio (10µM) were also investigated. Effects of PMCA4 ablation and AP2 (10µM) on global intracellular Ca2+ changes ([Ca2+]i) in pressurised mesenteric arteries were assessed after loading arteries with the Ca2+-sensitive indicator indo-1. PMCA4 ablation had no effect on the magnitude of arterial constrictions or on the changes of [Ca2+]i in response to KPSS (40mM & 100mM) or to noradrenaline. The passive intra-lumen diameter, wall thickness, wall to lumen diameter and cross sectional area of mesenteric arteries across the intravascular pressure range studied were also not modulated by PMCA4 ablation. A leftwards shift in the stress to strain relationship and significant increase in beta elastic modulus (β) were revealed in arteries from PMCA4 KO (-/-) mice compared to those from WT (+/+) mice, suggesting that PMCA4 ablation reduces mesenteric arterial distensibility. Acute PMCA4 inhibition with AP2, significantly reduced arterial constrictions and the increase in [Ca2+]i in response to noradrenaline in arteries from WT (+/+) mice, but had no effect on arterial constrictions elicited by arteries from PMCA4 KO (-/-) mice. Inhibitory effects of AP2 were not present in arteries after NOS inhibition by LNNA and also after nNOS inhibition with Vinly-L-Nio. Hence, PMCA4 inhibition with AP2 reduces vascular constriction by a nNOS-dependent mechanism.In conclusion, the main findings of the study were that ablation and acute inhibition of PMCA4 with AP2 have different effects on mouse mesenteric resistance arterial contractility. This study provides more insight into PMCA4 as a significant modulator of signalling within the vasculature via effects on nNOS.
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Tang, Ting 1982. "Investigating NNS English teachers' self-assessed language proficiency in an EFL context." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99610.
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The vast majority of secondary school English teachers in China are non-native English speakers (NNS). These teachers might not have adequate language proficiency to promote a communicative language environment for students. This has raised an ongoing discussion concerning the growing need to foster NNS teachers' communicative language proficiency, which has been identified as one of the most important qualifications for successful ESL/EFL (English as a Second Language/English as a Foreign Language) teachers (Murdoch, 1994; Kamhi-Stein & Lee, 1999; Nunan, 2003). In this study, 53 secondary NNS teachers from Chinese secondary schools were asked to self-assess their English proficiency as well as to specify the minimum level of proficiency that they felt was needed to teach English effectively at the secondary school level in seven skill domains (listening comprehension, speaking ability, reading comprehension, writing ability, pronunciation, vocabulary and grammar). Paired sample t tests revealed that statistically significant differences were identified in six of the seven skill domains. Teachers perceived substantial gaps between their English proficiency and the minimum level needed to teach effectively. Teachers' perceptions about the relationship between their language proficiency and their teaching expertise were also explored through face-to-face interviews. The findings provide valuable information and have implications for language teachers in EFL contexts as well as for teacher educators.
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Ranasinghe, Gamage Indeewari. "New Reactivity Involving N-Isothiocyanates: Aminothiocarbonylation and [3+2] Cycloadditions to Form Molecules Containing NNCS Motifs." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36042.
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Nitrogen-containing heterocycles are of vital importance for the pharmaceutical and agrochemical industries. The Beauchemin group has been studying rare, amphoteric nitrogen-substituted isocyanates over the past years, and showed that their [3+2] alkene cycloaddition and cascade reactions provide access to a variety of NNCO containing heterocyclic compounds. This triggered interest into the reactivity of the parent N-isothiocyanates, which are also rare, and led to the discovery of aminothiocarbonylation reactions. The products formed are azomethine imines which contain a cyclic -aminothiocarbonyl motif, thus providing a cycloaddition route to these useful dipoles from simple starting materials. Such aminothiocarbonylation reactions were developed with both alkenes and imines as substrates.Apart from cyclic azomethine imine formations, efforts have also been made toward forming the acyclic azomethine imines as intermediates. These intermediates undergo [3+2] cycloaddition to form thiocarbamoyl pyrazolidine derivatives, and a preliminary substrate scope for this new intermolecular reactivity is presented. Other preliminary results include an unexpected Chugaev type reactivity. Collectively, these results show that N-isothiocyanates hold significant potential for the development of new reactivity.
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Abdul, Rasool Khatijah Binti. "Discourse strategies for managing problems of understanding in native speakers (NSs)-non native-speakers (NNSs) converstations." Thesis, University of Sheffield, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.548634.
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Heaton, Daniel Anthony. "Role of nNOS in the autonomic control of cardiac excitability in cardiac physiological and pathophysiological states." Thesis, University of Oxford, 2005. http://ora.ox.ac.uk/objects/uuid:5dfc213d-7846-485d-93f1-1635a0018ef0.
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Coelho, Camila Henriques. "Análise da inibição da óxido nítrico sintase neuronal (nNOS) na liberação de vasopressina durante sepse experimental." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/60/60135/tde-30102009-022744/.
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A fisiopatologia da sepse se caracteriza por hipotensão acompanhada de aumento da secreção de vasopressina (AVP) na fase inicial e diminuição numa fase mais tardia. Essa hipotensão é em parte devido ao aumento da quantidade de óxido nítrico, que juntamente com outros mediadores tem sua produção aumentada durante a sepse. A óxido nítrico sintase (NOS) é responsável pela síntese deste mediador, e sua isoforma neuronal (nNOS) está presente no músculo esquelético, pulmões, testículos, próstata, pele e também nos neurônios vasopressinérgicos do hipotálamo. O presente trabalho avaliou a participação do óxido nítrico produzido pela isoforma neuronal de NOS sobre a secreção temporal de AVP durante a sepse experimental. Ratos Wistar receberam injeção i.p. de 7-nitroindazol (50mg/kg ou 80mg/kg), inibidor específico da NOS neuronal, ou DMSO 10% + óleo de gergelim na proporção 1:9 (veículo) e após 30 minutos foram submetidos ao estímulo séptico por ligadura e perfuração cecal (CLP) ou à operação fictícia (OF). Em um grupo de animais, a sobrevida foi avaliada durante 5 dias. Em outro grupo, os animais foram decapitados 0, 4, 6, 18 e 24 horas após a cirurgia e o sangue processado para determinação do hematócrito, sódio sérico, osmolalidade, proteínas, glicose, creatinina, nitrato sérico e AVP plasmática. A neurohipófise foi removida para a determinação do conteúdo de AVP, e o hipotálamo dissecado para a determinação da atividade da NOS total. A mortalidade observada após CLP não foi modificada com o pré-tratamento com 7-NI (50mg/kg), assim como os aumentos temporais de hematócrito, glicose e nitrato sérico observados. As proteínas plasmáticas e o sódio sérico apresentaram diminuição após CLP e o pré-tratamento com 7-NI antecipou a perda proteica e postergou a diminuição do sódio sérico. Os animais após CLP não apresentaram alterações de creatinina e osmolalidade, entretanto quando prétratados com 7-NI, apresentaram aumento em 6 e 18 horas e diminuição a partir de 4hs, respectivamente. A atividade da NOS total no hipotálamo aumentou nos tempos determinados de 4 e 24 horas após CLP e este aumento foi reduzido com o prétratamento com o 7-NI nas doses de 50 e 80mg/kg, respectivamente. O conteúdo neurohipofisário de AVP diminuiu em 4, 6 e 18 horas após CLP e o pré-tratamento com 7-NI reduziu os estoques apenas em 0 e 6 horas. As concentrações plasmáticas de vasopressina apresentaram-se aumentadas sómente 6 horas após CLP e o pré-tratamento não alterou essas concentrações. Esses resultados permitem concluir que o NO produzido pela NOS neuronal não teria uma tarefa substancial na secreção de vasopressina durante sepse experimental.The pathophysiology of sepsis is caracterized by hypotension accompanied by increase of vasopressin secretion (AVP) in early phase and decrease during late phase. This hypotension is due, in part, to the increase of nitric oxide (NO) production, that, like other mediators, shows high production during sepsis. Nitric oxide synthase (NOS) is responsible by synthesis of NO. The neuronal isoform of NOS is present in skeletic muscle, testicles, prostate, skin and vasopressinergics neurons of hypothalamus. The present work evaluated the participation of nitric oxide produced by neuronal NOS in temporal vasopressin secretion during experimental sepsis. Rats Wistar received intraperitoneal injection of 7-nitroindazole (50 or 80 mg/kg), an inhibitor of neuronal nitric oxide synthase activity, or DMSO 10% + sesame oil in the proportion 1:9 (vehicle) and after 30 minutes, they were submited to septic stimulus by cecal ligation and puncture (CLP) or to sham operation. In one of the groups, the survival rate was evaluated during 5 days. In other group, the animals were decapited 0, 4, 6, 18 and 24 hours after CLP and the blood was processed to determinate haematocrit, serum sodium, osmolality, proteins, glucose, creatinine, serum nitrate, and plasma AVP. Neurohypophysis was removed to determination of vasopressin content, and hypotalamus was dissected to determinate total NOS activity. Mortality observed after CLP was not affected by periferal injection of 7-nitroindazole (50 mg/kg) as well as haematocrit, glucose and nitrate increase. Serum sodium and plasma protein decreased after CLP and the treatment antecipated the loss protein, and delayed serum sodium decrease. CLP animals didn\'t show creatinine and osmolality alterations, but when treated with 7-nitroindazole, showed increase 6 and 18 hours, and decrease 4 hours, respectively. NOS activity in hypothalamus increased 4 and 24 hours after CLP, and was reduced with 7-NI pretreatment (50 and 80 mg/kg respectively). AVP neurohypophysis content diminished 4, 6 and 18 hours after CLP and 7-NI reduced the content just at 0 and 6 hours. Vasopressin plasma concentration increased just 6 hours after CLP and 7-NI pretreatment didn\'t alter this parameter. We concluded that NO produced by neuronal NOS doesn\'t have a substantial role in vasopressin secretion during experimental sepsis.
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Rabu, Pierre. "Etude cristallochimique des composes a structure composite incommensurable (lns)#nnbs#2 (ln : yttrium, elements terre-rare)." Nantes, 1990. http://www.theses.fr/1990NANT2027.
Full textAbstract:
Les composes (lns)#nnbs#2 constituent une nouvelle famille parmi les materiaux a structure composite incommensurable. Les travaux effectues portent principalement sur une methode de resolution structurale systematique adaptee a ce type de structure, suivant des approches cristallographiques variees: 1) une approche composite avec separation d'entites structurales a symetrie propre; 2) une approche grande maille dans l'approximation commensurable; 3) une approche incommensurable faisant appel aux notions de groupe de super-espace de dimension 4. Ces edifices sont decrits comme l'empilement de feuilles de composition chimique et de symetrie differentes lns et nbs#2. Une etude preliminaire des proprietes de transport et de la susceptibilite magnetique a permis de lier les proprietes de conduction par trous a la presence de couches nbs#2 et les proprietes magnetiques a la presence d'ions ln#3#+ au sein des couches lns. Certains membres de cette famille sont supraconducteurs a basse temperature
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Iyomasa, Daniela Mizusaki. "Avaliação dos efeitos do estresse crônico sob a ansiedade e a sensibilidade nociceptiva em ratos mantidos em ambiente enriquecido." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/59/59134/tde-24052018-222146/.
Full textAbstract:
Respostas adaptativas ao estresse podem ser acompanhadas por alterações nos comportamentos emocionais, em particular relacionados com medo e ansiedade, bem como alterações na sensibilidade dolorosa. Ainda, tem sido investigado o papel do óxido nítrico em áreas encefálicas relacionadas ao comportamento defensivo. Embora várias evidências têm demonstrado que o enriquecimento ambiental promove melhora nos processos de memória, no aprendizado e em respostas nociceptivas, a relação entre o estresse crônico e as vantagens da utilização do enriquecimento ambiental ainda são pouco investigadas. O presente estudo teve como objetivo investigar se o enriquecimento ambiental promove alteração do comportamento emocional, da sensibilidade nociceptiva, bem como na imunorreatividade à nNOS no núcleo central da amígdala, na formação hipocampal e na região dorsolateral da substância cinzenta periaquedutal, em ratos submetidos ao estresse por isolamento social ou estresse crônico variado e mantidos em ambiente enriquecido ou sem enriquecimento. Ratos machos Wistar (~70g) foram divididos aleatoriamente em dois grandes grupos experimentais: Ambiente Padrão (Padrão) ou Ambiente Enriquecido (EE), mantidos por 38 dias. Cada grupo foi subdividido dependendo do tipo de estresse crônico: Controle (sem estresse), Isolamento Social (por 38 dias) e Estresse Crônico Variado (do dia 28 ao dia 37). Ao fim do tempo experimental (dia 38) os ratos foram avaliados quanto ao comportamento emocional pelos testes de labirinto em cruz elevado (LCE) e claro/escuro (TCE) e sensibilidade nociceptiva pelo teste da placa quente (a qual foi realizada em duas etapas, sendo a primeira medida no dia 0 e outra no dia 38). A eutanásia dos ratos ocorreu no dia 39, para coleta do encéfalo para análise da imunorreatividade à óxido nítrico sintase neuronal (nNOS). Levando-se em consideração o comportamento emocional e a sensibilidade nociceptiva, os diferentes tipos de estresse crônico diminuíram a porcentagem de tempo, a frequência de entrada e a exploração da extremidade dos braços abertos e na frequência de mergulho de cabeça no teste do LCE, apesar de não alterar a sensibilidade nociceptiva. Por outro lado, o enriquecimento ambiental aumentou a porcentagem de tempo, a frequência de entrada e a exploração da extremidade dos braços abertos no teste do LCE, apesar de não alterar a sensibilidade nociceptiva. Foi observado aumento da imunorreatividade à nNOS na formação hipocampal em diferentes tipos de estresse crônico. Em particular, na região de CA3 houve interação significante entre os fatores estresse por isolamento social e ambiente de manutenção. Deste modo, os resultados obtidos neste trabalho sugerem que a formação hipocampal desempenha importante função no efeito ansiogênico exercido pelos diferentes tipos de estressores crônicos (aqui representados pelo isolamento social e pelo estresse crônico variado) provavelmente pela ativação do sistema nitrérgico e sugere-se que o enriquecimento possa prevenir o comportamento do tipo ansioso.Adaptive responses to stress may be accompanied by changes in emotional behaviors, in particular related to fear and anxiety, as well as changes in pain sensitivity. Furthermore, the role of nitric oxide in brain areas related to defensive behavior has been investigated. Although several evidences have shown that environmental enrichment improves memory processes, learning and nociceptive responses, the relationship between chronic stress and the advantages of using environmental enrichment is still poorly investigated. The present study aimed to investigate whether environmental enrichment promotes alteration of the emotional behavior, nociceptive sensitivity, as well as immunoreactivity to neuronal nitric oxide synthase (nNOS) in the central nucleus of the amygdala, hippocampal formation and dorsolateral periaqueductal gray matter in rats submitted to social isolation stress or chronic unpredictable stress and reared in enriched environment or standard environment. Male Wistar rats (~ 70g) were randomly divided into two major experimental groups: Standard Environment (Standard) or Enriched Environment (EE), maintained for 38 days. Each group was subdivided according to the type of chronic stress: Control (without stress), Social Isolation (for 38 days) and Chronic Unpredictable Stress (from day 28 to day 37). At the end of the experimental time (day 38), the rats were evaluated for emotional behavior by elevated plus maze (EPM) and light/dark box (LDBT) tests and nociceptive sensitivity by the hot plate test (which was performed in two steps , the first being measured on day 0 and the other on day 38). Euthanasia of rats occurred on day 39, to collect the brain for nNOS immunoreactivity analysis. Taking into account emotional behavior and nociceptive sensitivity, the different types of chronic stress decreased the percentage of time, the frequency of entry of the open arms, end-arm exploration and the head dipping frequency in the EPM, despite of not altering the nociceptive sensitivity. On the other hand, environmental enrichment increased the percentage of time, the frequency of entry of the open arms and the end arm-exploration in the EPM test, although it did not alter the nociceptive sensitivity. Increased immunoreactivity to nNOS in hippocampal formation was observed in different types of chronic stress. In particular, in the CA3 region there was a significant interaction between stress factors due to social isolation and maintenance environment. Thus, the results obtained in this study suggest that hippocampal formation plays an important role in the anxiogenic effect exerted by the different types of chronic stressors (represented here by social isolation and by chronic chronic stress) probably due to the activation of the nitrergic system and it is suggested that environmental enrichment can prevent of anxiety-like behavior.
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Moda, Hari Priya. "Non-Negative Least Square Optimization Model for Industrial Peak Load Estimation." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/36003.
Full textAbstract:
Load research is the study of load characteristics on a power distribution system which helps planning engineer make decisions about equipment ratings and future expansion decisions. As it is expensive to collect and maintain data across the entire system, data is collected only for a sample of customers, where the sample is divided into groups based upon the customer class. These sample measurements are used to calculate the load research factors like kWHr-to-peak kW conversion factors, diversity factors and 24 hour average consumption as a function of class, month and day type. These factors are applied to the commonly available monthly billing kW data to estimate load on the system.
Among various customers on a power system, industrial customers form an important group for study as their annual kWHr consumption is among the highest. Also the errors with which the estimates are calculated are also highest for this class. Hence we choose the industrial class to demonstrate the Lawson-Hanson Non-Negative Least Square (NNLS) optimization technique to minimize the residual squared error between the estimated loads and the SCADA currents on the system. Five feeders with industrial dominant customers are chosen to demonstrate the improvement provided by the NNLS model. The results showed significant improvement over the Nonlinear Load Research Estimation (NLRE) method.Master of Science
34
Bird, Diane Carol. "An investigation into the role of neuronal nitric oxide synthase (nNOS) in the phencyclidine mouse model of schizophrenia." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0015/MQ57249.pdf.
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Hirsch, Tamara. "A behavioural evaluation of the potential of nNOS inhibitors to control dyskinesia in animal models of Parkinson's disease." Thesis, King's College London (University of London), 2012. https://kclpure.kcl.ac.uk/portal/en/theses/a-behavioural-evaluation-of-the-potential-of-nnos-inhibitors-to-control-dyskinesia-in-animal-models-of-parkinsons-disease(777432ce-93ec-429c-a5c8-41d42dd2069b).html.
Full textAbstract:
Long-term dopaminergic therapy in Parkinson’s disease (PD) can lead to motor complications including dyskinesia which can be treated with amantadine, an N-methyl-D-aspartate (NMDA) receptor antagonist. NMDA receptor activation is linked with nitric oxide (NO) production and changes in synaptic plasticity, suggesting a role in dyskinesia. This led to the hypothesis that NO, produced by neuronal nitric oxide synthase (nNOS), contributes to the occurrence and evolution of dyskinesia in PD. Therefore, these studies investigated the effects of nNOS inhibition, using the nNOS inhibitors ARR17477 and 7-nitroindazole (7-NI), on the dyskinesia expression and priming processes in rodent and primate models of PD following L-dopa and dopamine agonist treatment. To explore the role of nNOS inhibition on established dyskinesia, 6-OHDA-lesioned rats, primed to exhibit stable abnormal involuntary movements (AIMs), the rodent analogue of dyskinesia, were acutely challenged with nNOS inhibitors plus L-dopa or ropinirole. No reduction in AIMs was observed following nNOS inhibition. In order to investigate the potential for nNOS inhibitors to reduce the priming for AIMs, naïve 6-OHDA-lesioned rats were treated chronically with ARR17477 or 7-NI plus either L-dopa or ropinirole. Again, there was no beneficial effect of nNOS inhibition on the emergence of L-dopa- or ropinirole-induced AIMs. nNOS inhibition was also investigated in MPTP-treated primates, the gold standard behavioural model of PD. ARR17477 did not reduce the expression of established dyskinesia following L-dopa or ropinirole treatment. Similarly nNOS inhibition did not attenuate L-dopa-induced priming for dyskinesia in this model. In conclusion, inhibition of nNOS in 6-OHDA-lesioned rats and MPTP-treated primates did not reduce the expression or priming of L-dopa- or ropinirole-induced dyskinesia. These findings do not support a role for nitric oxide in processes underlying dyskinesia and suggest that nNOS inhibitors would not be beneficial in either preventing or attenuating motor complications in PD patients.
36
Murphy, Timothy G. "The Use of Film in a First Year College Writing Class for ESL Students." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/565898.
Full textAbstract:
The inclusion of film is becoming ever-more popular in the field of First Year College Writing Classes for NES and NNES students around the country. Many of the reasons for this are self-evident. Film frequently offers a strong emotional appeal to NNES students and more opportunities to access what may otherwise be linguistically inaccessible material (e.g., Stempleski, 1990; Kasper, 2000). In addition, film offers a pleasant alternative to the use of literature in a First Year Writing Class which can often intimidate or discourage many NNES students due to its linguistic complexity (McKay, 1982). What is less clear, however, is how film's inclusion may contribute to the development of academic writing skills in similar or different ways from print texts, such as short stories, poems, and essays. Therefore, this dissertation will compare the benefits and challenges of using film and print texts in a First Year College Writing Class for NNES students. From data gathered from student essays, interviews, surveys, and field notes, the current study addresses the following research questions: (1. What linguistic and rhetorical features characterize the style of academic discourse NES and NNES students produce about films compared to print texts? (2. What challenges do NNES freshman composition students face writing academic essays about films compared to writing about print texts? (3. What academic strategies do they say they use to try to overcome these challenges? Do any academic strategies correspond with particular linguistic and rhetorical features? (4. What are NNES students' opinions regarding watching and writing about films in a university composition class? Do students consider watching and writing about a film comparable as an academic activity to reading and writing about a print text? The study aims to contribute to the field of Second Language Writing literature by considering the impact of the choice of text form, either a movie or a print text, on NNES students' motivation and ability to write academic, college-level essays. Further, it will explore in what ways students' cultural, educational and linguistic backgrounds affect the ways they approach writing about a film and a print text. This knowledge should be especially helpful for Writing Program Administrators and First Year College Writing Teachers for NNES students. It should be noted that, as a result of this dissertation's findings, the researcher has changed his approach toward the use of film in a First Year College Writing class for NNES students. Descriptions of activities the researcher currently uses before and after screening a film are included in the final chapter of this dissertation.
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Denadai, Magda Aline. "Efeitos do 7-nitroindazole, um inibidor da sintase neuronal do oxido nitrico (nNOS), sobre o condiciomaneto contextural em pombos." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314745.
Full textAbstract:
Orientador: Elenice Aparecida de Moraes FerrariDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-11T20:16:54Z (GMT). No. of bitstreams: 1 Denadai_MagdaAline_M.pdf: 823511 bytes, checksum: 1887972f9e5047fecbd7195247b586a8 (MD5) Previous issue date: 2008
Resumo: O óxido nítrico (NO), um neurotransmissor não convencional, tem papel importante em processos neurobiológicos de comportamento e de memória. Sua síntese é mediada por três isoformas de sintase do óxido nítrico (NOS): a neuronal (nNOS), a endotelial (eNOS) e induzível (iNOS). Este trabalho analisou o efeito do 7-nitroindazole (7-NI), um inibidor seletivo da nNOS, no condicionamento clássico aversivo em pombos. Foram usados 4 grupos: tratados com 7-NI (grupo 7-nitroindazole; G7-NI, n=5), tratados com óleo de amendoim (grupo veículo; GV, n=5), controle/sem tratamento (grupo controle; GC, n=5) e grupo não tratado/não condicionado (grupo manipulação; GM, n=5). A administração i.p. de 7-NI (25 mg/kg), ou do óleo de amendoim foi feita imediatamente após o treinamento. O G7-NI, o GV e o GC receberam três associações som-choque (5°, 10° e 15º minutos) numa sessão de 20 min. O teste a o contexto foi realizado 24 horas depois. As sessões foram gravadas para posterior transcrição e análise comportamental. A ocorrência da resposta de congelamento durante o treino não diferiu entre os grupos (p>0,05), mas durante o teste foi menor para o G7-NI em comparação ao treino (p<0.01) e aos demais grupos no teste (p<0.001). A atividade da NOS dependente de Ca++ no hipocampo foi menor no G7-NI do que nos outros grupos (p<0,01). Análise por Western blot indicou aumento na expressão de nNOS no G7-NI (p<0,05). A administração sistêmica de 7-NI teve um efeito amnésico sobre a memória contextual aversiva, indicando que a atividade da NOS dependente de Ca++ é importante para os processos de condicionamento clássico aversivo em pombos.
Abstract: Nitric oxide (NO) is an unsual neurotransmitter that plays an important role in neurobiological functions underlying behavior and memory. NO synthesis and release can be mediated by three isoforms of NO synthases (NOS): neuronal (nNOS), endothelial (eNOS) and inducible (iNOS). This study examined the effect of 7-nitroindazole (7-NI), a selective nNOS inhibitor, on contextual fear conditioning in pigeons. Four groups of pigeons were used: treated with 7-NI (7-NI; n=5), treated with peanut oil (Vehicle; n=5), non treated controls (Control; n=5) and non treated and no-trained controls (Non-trained; n=5). Treatment consisted in 7-NI (25 mg/kg; i.p.) or vehicle (peanut oil) administration, immediately after training. All the animals were trained in one 20 min session during which three tone-shock pairings (5th, 10th and 15th minutes) were presented. The test to the context was conducted 24h later. Behavioral categories were analyzed through the transcription of video-tapes of the sessions. The groups 7-NI, Vehicle and Control showed no significant differences in freezing during the conditioning session (p>0.05). During the test to the context the group 7-NI expressed significantly lower freezing as compared to Vehicle and Control (p<0.05). The 7-NI pigeons showed lower hippocampal activity of Ca++ dependent-NOS than Vehicle and Control groups (p<0.01). Western blot analysis indicated significant increase in nNOS expression (p<0.05). The systemic administration of 7-NI induced amnestic effects on contextual fear memory that evidence that Ca++-dependent NOS activity is required for fear conditioning in pigeons.
Mestrado
Fisiologia
Mestre em Biologia Funcional e Molecular
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Eskandari, Julia Mirjam [Verfasser], Viktoria [Akademischer Betreuer] Kolb-Bachofen, Daniela [Akademischer Betreuer] Bruch-Gerharz, and Ulrich [Akademischer Betreuer] Germing. "Untersuchungen zur nNOS an psoriatischer Haut / Julia Mirjam Eskandari. Gutachter: Daniela Bruch-Gerharz ; Ulrich Germing. Betreuer: Viktoria Kolb-Bachofen." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2011. http://d-nb.info/1018272518/34.
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Schonhoff, Christopher M. "The Regulation of nNOS During Neuronal Differentiation and the Effect of Nitric Oxide on Hdm2-p53 Binding: a Dissertation." eScholarship@UMMS, 2000. https://escholarship.umassmed.edu/gsbs_diss/57.
Full textAbstract:
Nitric oxide is a ubiquitous signaling molecule with both physiological and pathological functions in biological systems. Formed by the enzymatic conversion of arginine to citrulline, NO, has known roles in circulatory, immune and nervous tissues. In the nervous system nitric oxide has been implicated in long-term potentiation, neurotransmitter release, channel function, neuronal protection and neuronal degeneration. Much of our work has focused on yet another role for nitric oxide in cells, namely, neuronal differentiation.
During development, neuronal differentiation is closely coupled with cessation of proliferation. We use nerve growth factor (NGF)-induced differentiation of PC12 pheochromocytoma cells as a model and find a novel signal transduction pathway that blocks cell proliferation. Treatment of PC12 cells with NGF leads to induction of nitric oxide synthase (NOS). The resulting nitric oxide (NO) acts as a second messenger, activating the p21(WAF1) promoter and inducing expression of p21(WAF1) cyclin-dependent kinase inhibitor. NO activates the p21(WAF1) promoter by p53-dependent and p53-independent mechanisms. Blocking production of NO with an inhibitor of NOS reduces accumulation of p53, activation of the p21(WAF1) promoter, expression of neuronal markers, and neurite extension. To deternine whether p21(WAF1) is required for neurite extension, we prepared a PC12 line with an inducible p21(WAF1) expression vector. Blocking NOS with an inhibitor decreases neurite extension, but induction of p21(WAF1) with isopropyl-1-thio-beta-D-galactopyranoside restored this response. Levels of p21(WAF1) induced by isopropyl-1-thio-beta-D-galactopyranoside were similar to those induced by NGF. Therefore, we have identified a signal transduction pathway that is activated by NGF; proceeds through NOS, p53 and p21(WAF1) to block cell proliferation; and is required for neuronal differentiation by PC12 cells.
In further studies of this pathway, we have examined the role of MAP kinase pathways in neuronal nitric oxide synthase (nNOS) induction during the differentiation of PC12 cells. In NGF-treated PC12 cells, we find that nNOS is induced at RNA and protein levels, resulting in increased NOS activity. We note that neither nNOS mRNA, nNOS protein nor NOS activity is induced by NGF treatment in cells that have been infected with a dominant negative Ras adenovirus. We have also used drugs that block MAP kinase pathways and assessed their ability to inhibit nNOS induction. Even though U0126 and PD98059 are both MEK inhibitors, we find that U0126, but not PD98059, blocks nNOS induction and NOS activity in NGF-treated PC12 cells. Also, the p38 kinase inhibitor, SB 203580, does not block nNOS induction in our clone of PC12 cells. Since the JNK pathway is not activated in NGF-treated PC12 cells, we determine that the Ras-ERK pathway and not the p38 or JNK pathway is required for nNOS induction in NGF-treated PC12 cells. We find that U0l26 is much more effective than PD98059 in blocking the Ras-ERK pathway, thereby explaining the discrepancy in nNOS inhibition. We conclude that the Ras-ERK pathway is required for nNOS induction.
The activation of soluble guanylate cyclase and the production of cyclic GMP is one of the best characterized modes of NO action. Having shown that inhibition of NOS blocks PC12 cell differentiation we tested whether nitric oxide acts through soluble guanylate cyclase to lead to cell cycle arrest and neuronal differentiation. Unlike NOS inhibition, the inhibition of soluble guanylate cylcase does not block the induction of neuronal markers. Moreover, treatment of NGF-treated, NOS-inhibited PC12 cells with a soluble analog of cyclic GMP was unable to restore differentiation of those cells. Hence, cGMP is not a component of this pathway and we had to consider other mechanisms of NO action.
It has become increasingly evident that another manner by which NO may exert its effects is by S-nitrosylation of cysteine residues. We tested, in vitro whether nitric oxide may control p53 by S-nitrosylation and inactivation of the p53 negative regulator, Hdm2. Treatment of Hdm2 with a nitric oxide donor inhibits Hdm2-p53 binding, the first step in Hdm2 regulation of p53. The presence of cysteine or DTT blocks this inhibition of binding. Moreover, nitric oxide inhibition of Hdm2-p53 binding was found to be reversible. Sulfhydryl-sensitivity and reversibility are consistent with nitrosylation. Finally, we have identified a critical cysteine residue that nitric oxide modifies in order to disrupt Hdm2-p53 binding. Mutation of this residue from a cysteine to an alanine does not interfere with binding but rather eliminates the sensitivity of Hdm2 to nitric oxide inactivation.
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McRae, Vicki. "Output, input and interaction in formal/informal teacher interactions and in NS, NNS children's interactions." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26884.
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Output, input and interaction are examined in this study for a native English speaking (NS) teacher and for native and non-native English speaking (NS, NNS) young children in two situations in the classroom, child organized and teacher organized. Video tapes and transcripts of fourteen samples of interactions in teacher organized situations and fourteen samples of naturally occurring interactions in child organized situations, each limited to the first consecutive one hundred utterances, were analyzed. Output was assessed in terms of verbal participation - utterances and words. Input and interaction were assessed both for discourse features (twelve negotiating devices) and in terms of the situational structure of the contexts that existed during the interactions - their distance from the speaker and the action was assessed with measures of exophoric and anaphoric reference (twenty-four reference items).
The results indicate: 1) that output or verbal participation varies for the teacher and the NS, NNS children with situation, 2) that discourse features, often used to assess input, vary in their use by the teacher and the children with the situational context, increase with verbal participation, and may not be useful measures of input, and 3) that the situational structure of the contexts that exist during teacher organized interactions and child organized interactions vary with situation - the distance of the language and the action from the speaker as well as the nature of the interaction. Individual variations amongst items, within and across groups are noted.
It is concluded that: 1) output, input and interaction vary with situation, 2) data analyses concerning input and interaction are more meaningful if they are related to the output occurring in different situations, and 3) L2 researchers will benefit from moving beyond the analysis of discourse features as the sole predictors of input during interaction to examine other aspects of the interaction situation.Education, Faculty of
Graduate
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Kececioglu, Ekin. "Analysis Of Immunoreactivity Of Nos Isoforms (nnos, Enos, Inos) In Hippocampus Of Young Rats Classified As Good And Poor Learners." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614994/index.pdf.
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Despite very extensive studies on molecular mechanisms of learning and memory formation it is little known about individual variation in the learning skills within a random animal population and about the differences in the brain biochemistry behind this variation. In the present study, we have focused on the expression and distribution of nitric oxide synthase (NOS), one of the molecules implemented in activity-dependent neuroplasticity, in the rat hippocampus, the structure critical for episodic memory in humans and animals. The aim of the present study was to investigate the differences in expression of three different NOS isoforms: neural (n), epithelial (e), and inducible (i), in four hippocampal subregions (CA1, CA3, DG, and hilus) between Wistar rats classified on the basis of their performance in partially baited 12-arm radial maze as &ldquogood&rdquo
and &ldquo
poor&rdquo
learners. The NOS isoforms were visualized on coronal hippocampal sections using fluorescent immunohistochemistry technique and n- and eNOS images were processed using ImageJ software, while iNOS immunoreactivity (IR) was assessed by counting immunoreactive cells. In this study, overall hippocampal levels of nNOS were significantly higher than those of eNOS and iNOS. The level of n and eNOS was higher in CA1 compared to DG/hilus areas, but lower than that in CA3 region. The expression of iNOS was the highest in CA1 and the lowest in hilus region. nNOS IR was significantly higher in &ldquo
poor&rdquo
than in &ldquo
good&rdquo
learners but only in CA1 region. No significant between-group differences were found in eNOS expression. iNOS expression was higher in &ldquo
poor&rdquo
learners but it did not reach the required significance level.
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Barua, Anupama. "The role of neuronal nitric oxide synthase (nNOS) in ischaemia/reoxygenation-induced injury and in protection of the mammalian myocardium." Thesis, University of Leicester, 2010. http://hdl.handle.net/2381/8754.
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Background: In physiological condition, NO is produced by two constitutive NOS isoform; eNOS and nNOS. Both isoforms have specific cellular locations and although the role of eNOS in myocardial ischaemic injury and in cardioprotection has been thoroughly addressed, but the role of nNOS remains unclear. Therefore, the aims of the thesis were to: (i) investigate the role of nNOS in ischaemia/reoxygenation-induced injury, (ii) determine whether its effect is species-dependent, (iii) elucidate the relationship of nNOS with mitoKATP channels and p38MAPK, two key components of IP and (iv) investigate whether modulation of the NO metabolism can overcome the unresponsiveness of the diabetic myocardium to IP. Methods and Results: Ventricular myocardial slices from rats and mice, nNOS knockout mice, and also from human right atrial slices were subjected to 90min ischaemia and 120min reoxygenation (37°C). Muscles were randomized to receive various treatments. Both the provision of exogenous NO and the inhibition of endogenous NO production significantly reduced tissue injury (creatine kinase release, cell necrosis and apoptosis), an effect that was species–independent. The protection seen with nNOS inhibition was as potent as that of IP, however, in nNOS-knocked out mice the cardioprotective effect of non-selective NOS (L-NAME) and selective nNOS inhibition (TRIM) and also that of IP was blocked while the benefit of exogenous NO remained intact. Additional studies revealed that the cardioprotection afforded by of exogenous NO and by inhibition of nNOS were unaffected by the mitoKATP channel blocker 5-HD although it was abrogated by p38MAPK blocker SB203580. Finally, in diabetic myocardium, IP did not decrease CK release neither reduced cell necrosis or apoptosis. In diabetic myocardium NO donor SNAP, inhibitor L-NAME and TRIM significantly reduced CK leakage, cell necrosis and apoptosis. Conclusions: nNOS plays a dual role in ischaemia/reoxygenation on that its presence is necessary to afford cardioprotection by IP but its inhibition reduces myocardial ischaemic injury. The role of nNOS is species-independent and exerted downstream of the mitoKATP channels and upstream of p38MAPK. Moreover, both the provision of exogenous NO and the suppression of endogenous NO production resulted in potent protection of diabetic human myocardium, overcoming the unresponsiveness of these tissues to IP.
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Pereira, Linus de Queiroz. "Silenciamento da expressão da enzima óxido nítrico sintase neuronal (nNOS) em linhagem de neuroblastoma via siRNAs sintéticos em dupla fita." reponame:Repositório Institucional da UnB, 2011. http://repositorio.unb.br/handle/10482/20854.
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, Programa de Pós-Graduação em Saúde Animal, 2011.Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2016-06-13T18:51:41Z No. of bitstreams: 1 2011_LinusQueirozPereira.pdf: 2001961 bytes, checksum: 8c777bf26af4a287663fdc2c8e5aa829 (MD5)
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O óxido nítrico (NO) é formado pelas enzimas NO sintases e desempenha papel na patogênese da neurodegeneração. NO sintase neuronais são expressas em áreas cerebrais lesionadas e sua inibição reduz efeitos de agentes neurotóxicos. O atual estudo desenvolveu siRNAs (small interfering RNAs) direcionados a duas sequências do RNAm de nNOS, presentes nos exons 2 e 28. Primeiramente, foi utilizado o algoritmo Biopredsi para identificar alvos de RNAi. Foi realizada síntese química dos siRNA duplos com 21 nucleotídeos - exon2_hnNOS e exon28hnNOS (Qiagen). Células de neuroblastomas SH-SY5Y receberam 150 pmol ou 300 pmol de cada siRNA estruturado em lipossomas (Lipofectamine 2000®, Invitrogen). Utilizou-se o controle negativo scramble All-Stars® (Qiagen). Os meios de cultivo celular utilizados foram Optimen® e DMEM® (Gibco), pelas primeiras 6h e para as 24h de incubação restantes, respectivamente. O conteúdo de RNAm de nNOS foi quantificado por PCR em tempo real via SYBR Green®; os efeitos de silenciamento foram apresentados pela expressão relativa (2-ΔΔCT). O nível de RNAm foi reduzido para até 60% do controle; os efeitos de silenciamento variaram de acordo com os alvos e doses. Os efeitos dos siRNA sobre a apoptose por neomicina foram determinados pelo ensaio de MTT. As células foram lesionadas por neomicina e tratadas com um dos siRNAs (exon2_hnNOS, exon28hnNOS ou scramble) por dois tempos distintos: imediatamente após ou 24h após a lesão. Ambas estruturas de siRNA mostraram efeitos antiapoptóticos, que alcançaram o máximo de 28,7%. Os efeitos variaram de acordo com o siRNA e o tempo de tratamento. Exon2_hnNOS produziu o maior efeito quando o tratamento foi realizado logo após lesão; exon28_hnNOS foi mais efetivo 24h após a lesão. Os resultados do atual estudo mostram a utilidade de siRNAs no entendimento da patogenia de doenças neurológicas e abrem novos caminhos para a terapia gênica de doenças neurodegenerativas.
Nitric oxide (NO) is formed by the NO synthase enzymes and play pivotal roles in the pathogenesis of neurodegenerative diseases. Neuronal NO synthase enzyme (nNOS) is expressed in brain areas submitted to injury, and its pharmacological blocking can decrease the effects of neurotoxic agents. In our study, we developed and tested two siRNAs targeted to two different nNOS mRNA sequences, located in the exons 2 and 28. Firstly, we used the Biopredsi algorithm to identify the RNAi targets. The synthetic siRNA duplexes with 21 nucleotides (exon2_hnNOS and exon28_hnNOS) were synthetized by Qiagen. Neuroblastoma cells SH-SY5Y received 150 pmol or 300 pmol of each siRNA mixed with Lipofectamine 2000® (Invitrogen). The negative control was the commercial scramble All-Stars® (Qiagen). The cell culture media used in this study were Optimen® and DMEM® (Gibco), for the first 6h and for the remaining 24h of incubation, respectively. The mRNA content was quantified by reverse transcription real-time PCR with SYBR Green® and the silencing effects on nNOS expressed by the relative expression (2-ΔΔCT). The nNOS mRNA content was reduced to 60% to the control level; the silencing effects varied according to the targets and doses used. To determine the effects of siRNA on the apoptotic phenotype, we used the MTT assay. Cells were lesioned by neomycin and treated with each of the siRNAs (exon2_hnNOS, exon28_hnNOS, or scramble) at two time-points: immediately after – or 24h after lesion. Both siRNA structures showed anti-apoptotic effects that reached 28.7%. The effects varied according to the siRNA used and the treatment time-point. Exon2_hnNOS produced the highest effect when the treatment began immediately after lesion; exon28_hnNOS was more effective 24h after lesion. Our results encourage the use of siRNAs to study the role of nNOS in the pathogenesis of brain diseases and highlighted a new therapeutic aproach for neurodegenerative diseases.
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McMeekin, Abigail L. "NS-NNS negotiation and communication strategy use in the host family versus the study abroad classroom." Thesis, University of Hawaii at Manoa, 2003. http://proquest.umi.com/pqdweb?index=0&did=765882961&SrchMode=1&sid=1&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1208804388&clientId=23440.
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Channing, O. Ernestien. "English written proficiency as a contributing factor to academic performance." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/65481.
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Internationally English is increasingly being used as a language of instruction in education. This is also true within the South African context, a country with eleven official languages. Many non-native English speaking (NNES) students, for whom English might be their second, third or even fourth language, are studying through the medium of English. Previous studies on this topic acknowledge that the level of English proficiency which NNES students have, affects their academic performance. The problem under investigation in this case study was the relationship between students’ academic performance in particular modules and how their written responses in examinations contributed to them failing a module. The purpose was to establish to which extent limited English proficiency contributed to the poor academic performance of NNES preservice teachers studying through distance education. This study is underpinned by Cummins’ theory of Basic Interpersonal Communication Skills and Cognitive Academic Language Proficiency (1984). It is supported by related literature which emphasises the challenges NNES students experience in understanding academic content and responding to written assessment tasks in a language other than their home language. A quantitative approach was used which focused on the written responses to examination papers of thirty undergraduate B Ed students who had failed a particular module, at a private higher education institution. The contribution of inadequate or incoherent English, as the reason why marks were not allocated to answers, was calculated and analysed. Results indicated that students’ English grammatical proficiency does have an influence on their academic performance, though it is not the main contributing factor to students failing their modules. For this case study it was determined that the pre-service teachers’ inadequate English written proficiency contributed almost a third (25,6%) of the reasons for their poor academic performance. This finding suggests the need to develop new teaching strategies to accommodate and offer language support to NNES students in higher education institutions that offer qualifications using English as the medium of instruction.Dissertation (MEd)--University of Pretoria, 2017.
Humanities Education
MEd
Unrestricted
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Balda, Mara A. "Ontogeny- and Sex-Dependent Contributions of the Neuronal Nitric Oxide Synthase (nNOS) Gene to Rewarding and Psychomotor Stimulating Effects of Cocaine." Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_dissertations/257.
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Multiple interactions between dopamine (DA), glutamate, and nitric oxide (NO) in mesolimbic and corticostriatal circuits suggest that NO may play a critical role in cocaine-induced behavioral and neural plasticity. Clinical and preclinical studies have revealed that females and adolescents display unique vulnerabilities to the behavioral and neurochemical effects of cocaine as a result of sex-dependent and ontogeny-dependent differences in dopaminergic systems. Thus, my research objectives were to investigate the contributions of the neuronal nitric oxide synthase (nNOS) gene, ontogeny, and gender on the rewarding and sensitizing effects of cocaine. I found that nNOS significantly influences the rewarding aspects of cocaine in adolescent mice and adult male mice (i.e., major deficits in several phases of cocaine conditioned place preference (CPP) were detected in nNOS knockout (KO) adolescent mice and nNOS KO adult male mice). However, the contribution of nNOS was sex-dependent as CPP phases were normal in KO adult females. In contrast to CPP, I found a major ontogeny-dependent contribution of nNOS to the sensitizing effects of cocaine. Namely, while nNOS is essential for the development of behavioral sensitization in adult males, this type of behavioral plasticity develops independently of nNOS during adolescence. The contribution of nNOS was once again sex-dependent as behavioral sensitization was normal in adult KO females. Together, this line of investigation has revealed that the NO-signaling pathway has a) a sex-dependent role in the neuroplasticity underlying cocaine CPP and b) a sex-dependent and ontogeny-dependent influence on cocaine-induced behavioral sensitization. Stereological and western blot analysis revealed that a sensitizing regimen of cocaine resulted in an increase in nNOS and tyrosine hydroxylase (TH) immunoreactivity in the dorsal striatum (dST) of adult, but not adolescent, wild-type (WT) male mice. In the absence of nNOS, dopaminergic neurons in the ventral tegmental area (VTA) were severely reduced and cocaine caused a downregulation of dST TH suggesting that nitrergic levels modulate TH. Thus, the finding that nNOS is essential for the development of sensitization in adulthood, but not adolescence, together with the fact that cocaine upregulated nNOS and TH in the dST in adult, but not adolescent mice, strongly suggest that the nitrergic system underlies behavioral sensitization through modulation of the dopaminergic system in adulthood. These findings suggest different approaches in the clinical treatment of drug craving and drug-seeking behavior in adolescent and adult patients.
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Lustosa, Cátia Valderês dos Santos Faria. "Interferência de RNA para silenciamento gênico da enzima NO sintase neuronal (nNOS) no modelo in vitro de neurodegeneração por interferon gama." reponame:Repositório Institucional da UnB, 2013. http://repositorio.unb.br/handle/10482/13967.
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2013.Submitted by Tania Milca Carvalho Malheiros (tania@bce.unb.br) on 2013-07-29T13:08:16Z No. of bitstreams: 1 2013_CatiaValderesSantosFariaLustosa_Parcial.pdf: 3115952 bytes, checksum: 57e3839be1f01cc4531234cdbb46186a (MD5)
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A vulnerabilidade de neurônios dopaminérgicos a insultos químicos continua sendo uma questão relevante na neuropatologia. Estudos anteriores revelam aumento dos níveis de interferon gama (IFN- ) e da enzima óxido nítrico sintase neuronal (nNOS) durante a injúria de células neuronais. Entretanto, até o momento, nenhum trabalho avaliou se a nNOS afeta a viabilidade de neurônios dopaminérgicos expostos ao IFN- . Para avaliar o papel da nNOS nas respostas celulares ao IFN- , o presente estudo realizou silenciamento gênico da enzima nNOS via interferência de RNA (RNAi) no modelo de neurodegeneração de células SH-SY5Y. Primeiro, analisou-se o conteúdo de RNAm de nNOS através de PCR em tempo real. Três RNAs interferentes sintéticos curtos foram testados nos tempos de 8h e 24h, em doses de 18,75nM e 37,5nM. Testou-se também um vetor de expressão de grampos curtos de RNA, denominado pnNOS_hum_4400 para o silenciamento da enzima. Os efeitos do silenciamento de nNOS sobre a viabilidade das células SH-SY5Y lesadas foram medidas via ensaio de 3-(4,5)-dimethylthiazol-2-y1)-2,5-diphenyltetrazolium bromide (MTT). O melhor efeito de silenciamento de nNOS ocorreu no tempo de 24h pós-transfecção para siRNAnNOShum_3987 e siRNAnNOShum_4400, com diminuição de 0,46 e 0,66 vezes. SiRNAnNOShum_4400 e o vetor pnNOS_hum_4400 aumentaram a viabilidade das células lesadas por IFN-y em 5,0 % e 15,8%, respectivamente. Conclui-se que a enzima nNOS participa de eventos celulares ligados à injúria de células SH-SY5Y causada pelo IFN- y. ______________________________________________________________________________ ABSTRACT
The vulnerability of dopaminergic neurons to chemical insults remains a relevant issue in neuropathology. Previous studies found increased levels of interferon gamma (IFN- ) and the neuronal nitric oxide synthase enzyme (nNOS) during neuronal injury. No previous work, however, has evaluated whether nNOS affects the viability of dopaminergic neurons exposed to IFN- . To gain more insight into the role of nNOS in cell responses to IFN- , the present study carried out the enzyme gene silencing by RNA interference (RNAi) in the neuron-like SH-SY5Y model of neurodegeneration. We first analyzed the nNOS mRNA knocking down by using a reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR). Three small interfering RNAs were tested at 8h and 24h in doses of 18.75nM and 37.5nM. We also tested a short-hairpin RNA expression vector named pnNOS_hum_4400 to improve enzyme knocking-down. nNOS silencing effects on the viability of injured SH-SY5Y cells were measured by the 3-(4,5)-dimethylthiazol-2-y1)-2,5-diphenyltetrazolium bromide (MTT) assay. The highest knocking down in nNOS mRNA content occurred at 24h post-transfection for siRNAnNOShum_3987 and siRNAnNOShum_4400, with 0.46 and 0.66 fold decrease. SiRNAnNOShum_4400 and the vector pnNOS_hum_4400 ameliorate the viability of cells injured by IFN- 5,0 % 15,8 % ely. We concluded that nNOS enzyme plays at least a partial role in SH-SY5Y cell degeneration caused by IFN-y .
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Anderson-Manrique, Julie F. "Design or detour? The non-native English-speaking (NNS) student in the community college developmental writing classroom." Thesis, Capella University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3712029.
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Each year hundreds of foreign-born and other non-native English speakers (NNS) enroll in U.S. public community colleges. More than 40% of these applicants do not pass the entrance exams and are then directed to take a series of noncredit courses before entering the mainstream freshmen composition. The word mainstream refers to the regularly credited courses that one takes to earn credits towards one’s certificate or degree program. There are studies comparing the non-native speakers (NNS) to native English speakers (NNS) in the freshmen composition class. Other studies examine the mainstream writing class from the NNS student writer’s point of view. However, there is no literature that discusses the placement of the NNS student in the developmental course from the perspectives of the NNS student, the developmental writing instructor, and the administrator. By interviewing NNS students in the developmental writing class, community college staff, faculty, and administrators who interact with these students, we gain multiple perspectives about the placement of this population in the developmental writing class. The results of this study inform community college educators that some NNS students in developmental writing courses may have detoured from the mainstream path with little regard for some of their cognitive, affective, or linguistic needs.
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Dezengrini, Renata. "HERPESVÍRUS BOVINO TIPOS 1, 2 E 5: SENSIBILIDADE A ANTIVIRAIS IN VITRO, PATOGENIA E TERAPÊUTICA EXPERIMENTAL EM COELHOS." Universidade Federal de Santa Maria, 2009. http://repositorio.ufsm.br/handle/1/4039.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorAspects of bovine herpesvirus 5 (BoHV-5) pathogenesis and experimental therapies against BoHV-1 and BoHV-5 were investigated in vitro and in inoculated rabbits. In chapter 1, we investigated the role of nitric oxide (NO), a component of innate immunity against pathogens, in the neurological disease by BoHV-5 in rabbits. Spectrophotometry for NO products revealed that NO levels were significantly increased in several regions of the brain of rabbits with neurological disease [F(4, 40)=3.33; P<0.02]. Quantification of NO levels in the brain at different time points after virus inoculation revealed a gradual increase [F(12, 128)=2.82; P<0,003], correlated spatially and temporally with virus dissemination within the brain and preceding the development of neurological signs. Thus, we propose that the overproduction of NO in the brain of BoHV-5-infected rabbits may participate in the pathogenesis of neurological disease. In chapter 2, the activity of three anti-herpetic drugs was tested against BoHV-1, BoHV-2 and BoHV-5 in vitro by plaque reduction assay. Acyclovir was moderately active against the three viruses; Gancyclovir was moderately effective against BoHV-2, and to a lesser extent against BoHV-5, being poorly active against BoHV-1. Foscarnet (PFA) exhibited the most pronounced antiviral activity, being the only drug that, at the concentration of 100 ìg/mL, completely inhibited plaque formation by all three viruses. In chapter 3, we report the activity of PFA in rabbits inoculated with BoHV-1 or BoHV-5. Rabbits inoculated with BoHV-5 and treated with 100 mg/kg of PFA presented mortality rates (11/22 or 50%) statistically lower than non-treated controls (21/22 ou 95.4%) (P<0.0008). A significant reduction in the mean virus titers was observed at day 3 pi, the peak of virus shedding [F(9,108) = 2,23; P<0.03]. Reduction in virus shedding, frequency, severity and duration of ocular signs were also observed in rabbits inoculated with BoHV-1 into the conjunctival sac, comparing to the controls. The prolonged incubation period and the reduction in the duration of the clinical course of the PFA-treated group was significant (P<0.005 and P<0.04, respectively). Therefore, the activity of PFA in vivo against BoHV-1 and BoHV-5 may be exploited in further experimental therapies. In chapter 4, we investigated the effect of the inhibition of the inducible isoform of nitric oxide synthase (iNOS), associated or not with PFA treatment, on neurological infection by BoHV-5 in rabbits. Groups of BoHV-5-inoculated rabbits were treated with the iNOS inhibitor aminoguanidine (AG); with PFA; with both drugs; or maintained as virus controls. Morbidity and mortality rates were 100% (6/6) in the groups AG and CV, 66.7% (4/6) in the group PFA and 83.3% (5/6) in the group AG+PFA. The incubation period was significantly lower (P<0.05) and the onset of neurological disease occurred earlier and was more severe in the group AG. These results demonstrate that treatment with PFA reduced morbidity and mortality rates associated to BoHV-5 infection, that AG treatment anticipated the development of neurological signs, and that the development of neurolocial disease was delayed in the group treated with both drugs. Taken together, these results contribute to the knowledge of the pathogenesis of BoHV-5 neurological disease and pave the way for other experimental pathogenesis and therapy studies.
Aspectos da patogenia da infecção neurológica pelo herpesvírus bovino 5 (BoHV-5) e terapias experimentais contra o BoHV-1 e BoHV-5 foram estudados in vitro e em coelhos inoculados. O capítulo 1 relata a investigação do papel do óxido nítrico (NO), um componente da imunidade inata contra patógenos, na doença neurológica produzida pelo BoHV-5 em coelhos. Espectrofotometria para os produtos de degradação do NO revelou um aumento significativo nos seus níveis em várias regiões do encéfalo de coelhos infectados (F(4, 40)=3.33; P<0,02). A quantificação do NO no encéfalo nos dias seguintes à inoculação viral revelou um aumento gradativo (F(12, 128)=2.82; P<0,003), correlacionado temporal e espacialmente com a invasão e disseminação viral, e precedendo o desenvolvimento de sinais neurológicos. Sugere-se, assim, que a produção aumentada de NO em resposta à infecção possa participar da patogenia dessa doença neurológica. No capítulo 2, investigou-se a atividade de três fármacos antivirais frente ao BoHV-1, BoHV-2 e BoHV-5 in vitro pelo teste de redução do número de placas. O Aciclovir foi moderadamente ativo frente aos três vírus; o Ganciclovir apresentou atividade moderada frente ao BoHV-2 e, em menor grau, contra o BoHV-5, sendo ineficaz frente ao BoHV-1. O Foscarnet (PFA) apresentou a atividade antiviral mais pronunciada, sendo o único fármaco que, na concentração de 100 μg/mL, inibiu completamente a produção de placas pelos três herpesvírus bovinos. No capítulo 3, investigou-se a atividade do PFA em coelhos inoculados com o BoHV-1 ou BoHV-5. Coelhos inoculados com o BoHV-5 e tratados com 100 mg/kg do PFA apresentaram índices de mortalidade (11/22; 50%) estatisticamente inferiores aos controles não-tratados (21/22; 93,7%) (P<0,0008). Uma redução significativa no título médio de vírus foi observada no dia 3 pi, pico da excreção viral [F(9,108) = 2,23; P<0,03]. Em coelhos inoculados no saco conjuntival com o BoHV-1 e tratados com o PFA, foram observadas reduções na excreção viral, na frequência, severidade comparando-se com o grupo controle. O período de incubação prolongado e a redução na duração do curso clínico no grupo tratado foi significante (P<0,005 e P<0,04, respectivamente). A atividade antiviral do PFA in vivo contra o BoHV-1 e BoHV-5 abre a perspectiva para outras terapias experimentais. No capítulo 4, investigou-se o efeito da inibição da isoforma induzível da enzima óxido nítrico sintase (iNOS), associada ou não ao tratamento com o PFA, na infecção neurológica pelo BoHV-5 em coelhos. Grupos de coelhos inoculados com o BoHV-5 foram tratados com o inibidor da iNOS aminoguanidina (AG); com PFA; com ambos os fármacos; ou não receberam tratamento. Os índices de morbidade e mortalidade foram de 100% (6/6) nos grupos AG e controle; 66,7% (4/6) no grupo PFA e 83,3% (5/6) no grupo AG+PFA. O período de incubação foi significativamente menor (P<0,05) e os sinais neurológicos foram mais precoces e severos nos animais do grupo AG. Portanto, o tratamento com PFA reduziu a morbidade e mortalidade associadas com a infecção pelo BoHV-5; o tratamento com AG resultou no agravamento e na antecipação do quadro neurológico e no grupo tratado com ambos os fármacos observou-se um desenvolvimento mais tardio dos sinais neurológicos. Esses resultados contribuem para o conhecimento da patogenia da doença neurológica pelo BoHV-5 e abrem perspectivas para estudos adicionais de patogenia e terapêutica anti-herpesvírus.
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Silva, Maria Isabel. "Distribuição de celulas imunorreativas para sintase neuronal do oxido nitrico (nNOS) no hipocampo de pombos (Columba livia) apos aprendizagem de escolha alimentar." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314142.
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Orientadores: Elenice Aparecida de Moraes Ferrari, Claudio Antonio Barbosa de ToledoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: O hipocampo exerce papel fundamental no processamento de aprendizagem e memória espaciais. Comparações das características funcionais, anatômicas e neuroquímicas do hipocampo são favorecidas por evidência oriunda de estudo sobre aprendizagem especial em mamíferos e aves. O objetivo do presente estudo foi analisar a marcação imunohistoquímica de células nNOS- positivas no hipocampo de pombos (C. lívia) após diferentes duração do treino em aprendizagem especial. Foram analisados grupos de animais não treinados (MAN), treinados em 1 sessão (EXP1), treinados em 5 sessões (EXP5), exposto à arena em 1 sessão (CONT1) ou em 5 sessões (CONT5). As sessões foram realizadas numa arena onde havia quatro comedouros, um dos quais com alimento. Em cada sessão, com seis tentativas, registrou-se a latência (seg) e a assertividade da escolha de um comedouro. Após os testes comportamentais, usou-se imunoistoquímica para a análise da marcação de células nNOS-positiva no hipocampo dorsal e ventral. O grupo EXP5 teve diminuição da latência de escolha ('F IND. 4,28¿= 23,74; p < 0,001) e aumento das respostas corretas ('F IND. 4,35¿= 8,66; p < 0,001) em função do treino. A marcação das células nNOS-positivas no hipocampo foi significativamente maior no hipocampo dorsal dos animais EXP5 em comparação com o hipocampo ventral ('F IND. 4,22¿= 104,79; p<0,001) e com os demais grupos ('F IND. 4,22¿= 10,17; p < 0,001). O aumento da imunorratividade de células nNOS- positivas no hipocampo dorsal de pombos após a aprendizagem da localização do comedouro correto sugere o envolvimento desta região e de processos mediados pro transmissão glutamatérgica nesse processo de aprendizagem e memória em pombos
Abstract: The hippocampus has fundamental role in spatial learning and memory processes. Functional and neurochemical analysis of the hippocampus are favored by evidence on spatial learning in mammals and birds. The present study examined the immunohistochemical expression of nNOS-positive cells in the hippocampus of pigeons (C. livia) after training in food location task. Animals were trained in one (EXP1) or five (EXP5) sessions or had one (CONT1) or five sessions (CONT5) of exposure to the experimental arena. The six trials sessions were conducted daily in one arena with 4 food bowls, one of which had food. Latency and accuracy of choise recorded. After behavioral tests, nNOS immunoractivity in hippocampal cells was analyzed. EXP 5 showed reduction imunoreactivity in hippocampal cells was analysed. EXP5 showed reduction in latency of choise ('F IND. 4,28¿= 23,74; p < 0,001) and increassis in correct choise ('F IND. 4,35¿= 8,66; p < 0,001) as function of the training. The expression of nNOS- positive cells was significantily higher in the dorsal hippocampus of EXP5 group as compared with the ventral hippocampus ('F IND. 4,22¿= 104,79; p < 0,001) and the other groups ('F IND. 4,28¿= 10,17; p < 0,001). The increases of nNOS immunoreactive neurons after learning of the food location suggest that nNOS is involved in processes of spatial learning and memory that are mediated by the dorsal hippocampus of pigeons
Mestrado
Fisiologia
Mestre em Biologia Funcional e Molecular