911 resultados para National Archives of Malta National Memory Project
Resumo:
A pesquisa trata do estudo da implantação de uma incubadora de empresas no município de Santana de Parnaíba em 2005. Duas perguntas estruturaram a investigação: Quais fatores ou indicadores econômicos e sociais, conforme previsto no Programa Nacional de Apoio à Implantação de Incubadoras de Empresas, se evidenciaram como viabilizadores, ou não, para a escolha do tipo de incubadora implantada no município? A incubadora de Santana de Parnaíba configurou-se ou não como espaço articulado de desenvolvimento econômico e social? Essas questões norteadoras determinaram o objetivo geral do estudo e os objetivos específicos, quais foram: investigar se houve ou não a aplicação do Estudo de Viabilidade Técnica e Econômica/SEBRAE; levantar o perfil socioeconômico do empreendedor local e, identificar o perfil das empresas graduadas quanto à geração de postos de trabalho. Para atender aos objetivos optou-se pela realização de pesquisa qualitativa de caráter exploratório e descritivo. A estratégia da observação participante foi seguida a partir da consulta aos diários de campo e às fontes primárias e secundárias, com a leitura e consulta de documentos e registros da implantação nos arquivos da FIESP. Como parte da estratégia de coleta de dados foi aplicado, junto ao universo da pesquisa, empreendedores e coordenador executivo do Programa de Incubadoras da FIESP, roteiro semiestruturado de questões. As informações foram analisadas mediante a técnica de análise de conteúdo, seguindo a metodologia do Estudo de Caso. Serviu de motivo condutor a constatação de que a notável evolução de tecnologias propiciada pelo sistema capitalista, o avanço dos processos produtivos e o aumento da produtividade nas grandes corporações ocorreram e continuam ocorrendo em ritmo sensivelmente superior à dinâmica de capacitação e qualificação da mão de obra em países em desenvolvimento, o que faz crescer o desemprego e a informalidade. A recente crise americana, em 2008, configura a oportunidade para melhor compreensão do conceito de incubadoras de empresas e demais empreendimentos solidários. Os resultados da pesquisa indicam que todos os empreendedores receberam informações de marketing e finanças. O apoio de consultorias especializadas, a participação em feiras e o desenvolvimento do plano de negó cios ao longo da incubação contemplaram as expectativas dos empreendimentos de tecnologia difundida. A pesquisa indica que, nos empreendimentos de base tecnológica, a incubadora não concretizou apoio efetivo às demandas por novos processos e novos produtos. Disso decorreu o atendimento deficitário às metas de geração de emprego na localidade pelas três empresas de base tecnológica instaladas na incubadora. Os resultados indicam que, apesar da significativa quantidade de documentos de conteúdo normativo que tratam da prevenção de insucessos de políticas públicas de apoio à implantação de incubadoras e ao empreendedorismo, não foi possível constatar indícios de articulação entre desenvolvimento econômico e desenvolvimento social nem de Estudo de Viabilidade Técnica e Econômica precedendo a implantação da incubadora no município estudado.(AU)
Resumo:
A cross-maze task that can be acquired through either place or response learning was used to examine the hypothesis that posttraining neurochemical manipulation of the hippocampus or caudate-putamen can bias an animal toward the use of a specific memory system. Male Long-Evans rats received four trials per day for 7 days, a probe trial on day 8, further training on days 9–15, and an additional probe trial on day 16. Training occurred in a cross-maze task in which rats started from a consistent start-box (south), and obtained food from a consistent goal-arm (west). On days 4–6 of training, rats received posttraining intrahippocampal (1 μg/0.5 μl) or intracaudate (2 μg/0.5 μl) injections of either glutamate or saline (0.5 μl). On days 8 and 16, a probe trial was given in which rats were placed in a novel start-box (north). Rats selecting the west goal-arm were designated “place” learners, and those selecting the east goal-arm were designated “response” learners. Saline-treated rats predominantly displayed place learning on day 8 and response learning on day 16, indicating a shift in control of learned behavior with extended training. Rats receiving intrahippocampal injections of glutamate predominantly displayed place learning on days 8 and 16, indicating that manipulation of the hippocampus produced a blockade of the shift to response learning. Rats receiving intracaudate injections of glutamate displayed response learning on days 8 and 16, indicating an accelerated shift to response learning. The findings suggest that posttraining intracerebral glutamate infusions can (i) modulate the distinct memory processes mediated by the hippocampus and caudate-putamen and (ii) bias the brain toward the use of a specific memory system to control learned behavior and thereby influence the timing of the switch from the use of cognitive memory to habit learning to guide behavior.
Resumo:
The function of the immune system is highly dependent on cellular differentiation and clonal expansion of antigen-specific lymphocytes. However, little is known about mechanisms that may have evolved to protect replicative potential in actively dividing lymphocytes during immune differentiation and response. Here we report an analysis of telomere length and telomerase expression, factors implicated in the regulation of cellular replicative lifespan, in human B cell subsets. In contrast to previous observations, in which telomere shortening and concomitant loss of replicative potential occur in the process of somatic cell differentiation and cell division, it was found that germinal center (GC) B cells, a compartment characterized by extensive clonal expansion and selection, had significantly longer telomeric restriction fragments than those of precursor naive B cells. Furthermore, it was found that telomerase, a telomere-synthesizing enzyme, is expressed at high levels in GC B cells (at least 128-fold higher than those of naive and memory B cells), correlating with the long telomeres in this subset of B cells. Finally, both naive and memory B cells were capable of up-regulating telomerase activity in vitro in response to activation signals through the B cell antigen receptor in the presence of CD40 engagement and/or interleukin 4. These observations suggest that a novel process of telomere lengthening, possibly mediated by telomerase, functions in actively dividing GC B lymphocytes and may play a critical role in humoral immune response by maintaining the replicative potential of GC and descendant memory B cells.
Resumo:
Pregnenolone sulfate (PREG S) is synthesized in the nervous system and is a major neurosteroid in the rat brain. Its concentrations were measured in the hippocampus and other brain areas of single adult and aged (22–24 month-old) male Sprague–Dawley rats. Significantly lower levels were found in aged rats, although the values were widely scattered and reached, in about half the animals, the same range as those of young ones. The spatial memory performances of aged rats were investigated in two different spatial memory tasks, the Morris water maze and Y-maze. Performances in both tests were significantly correlated and, accompanied by appropriate controls, likely evaluated genuine memory function. Importantly, individual hippocampal PREG S and distance to reach the platform in the water maze were linked by a significant correlation, i.e., those rats with lower memory deficit had the highest PREG S levels, whereas no relationship was found with the PREG S content in other brain areas (amygdala, prefrontal cortex, parietal cortex, striatum). Moreover, the memory deficit of cognitively impaired aged rats was transiently corrected after either intraperitoneal or bilateral intrahippocampal injection of PREG S. PREG S is both a γ-aminobutyric acid antagonist and a positive allosteric modulator at the N-methyl-d-aspartate receptor, and may reinforce neurotransmitter system(s) that decline with age. Indeed, intracerebroventricular injection of PREG S was shown to stimulate acetylcholine release in the adult rat hippocampus. In conclusion, it is proposed that the hippocampal content of PREG S plays a physiological role in preserving and/or enhancing cognitive abilities in old animals, possibly via an interaction with central cholinergic systems. Thus, neurosteroids should be further studied in the context of prevention and/or treatment of age-related memory disorders.
Resumo:
The high vocal center (HVC) controls song production in songbirds and sends a projection to the robust nucleus of the archistriatum (RA) of the descending vocal pathway. HVC receives new neurons in adulthood. Most of the new neurons project to RA and replace other neurons of the same kind. We show here that singing enhances mRNA and protein expression of brain-derived neurotrophic factor (BDNF) in the HVC of adult male canaries, Serinus canaria. The increased BDNF expression is proportional to the number of songs produced per unit time. Singing-induced BDNF expression in HVC occurs mainly in the RA-projecting neurons. Neuronal survival was compared among birds that did or did not sing during days 31–38 after BrdUrd injection. Survival of new HVC neurons is greater in the singing birds than in the nonsinging birds. A positive causal link between pathway use, neurotrophin expression, and new neuron survival may be common among systems that recruit new neurons in adulthood.
Resumo:
CCAAT/enhancer binding protein δ (C/EBPδ) is a transcriptional regulator implicated in the hepatic acute phase response and in adipogenic and myeloid cell differentiation. We found that C/EBPδ is widely expressed in the peripheral and central nervous systems, including neurons of the hippocampal formation, indicating a role in neural functions. To examine the role of C/EBPδ in vivo, we generated mice with a targeted deletion of the C/EBPδ gene. This mutation does not interfere with normal embryonic and postnatal development. Performance in a battery of behavioral tests indicates that basic neurological functions are normal. Furthermore, performance in a Morris water maze task suggests that C/EBPδ mutant mice have normal spatial learning. However, in the contextual and auditory-cue-conditioned fear task, C/EBPδ null mice displayed significantly more conditioned freezing to the test context than did wild-type controls, but equivalent conditioning to the auditory cue. These data demonstrate a selectively enhanced contextual fear response in mice carrying a targeted genomic mutation and implicate C/EBPδ in the regulation of a specific type of learning and memory.
Resumo:
The CD8+ T cell diaspora has been analyzed after secondary challenge with an influenza A virus that replicates only in the respiratory tract. Numbers of DbNP366- and DbPA224-specific CD8+ T cells were measured by tetramer staining at the end of the recall response, then followed sequentially in the lung, lymph nodes, spleen, blood, and other organs. The extent of clonal expansion did not reflect the sizes of the preexisting memory T cell pools. Although the high-frequency CD8+ tetramer+ populations in the pneumonic lung and mediastinal lymph nodes fell rapidly from peak values, the “whole mouse” virus-specific CD8+ T cell counts decreased only 2-fold over the 4 weeks after infection, then subsided at a fairly steady rate to reach a plateau at about 2 months. The largest numbers were found throughout in the spleen, then the bone marrow. The CD8+DbNP366+ and CD8+DbPA224+ sets remained significantly enlarged for at least 4 months, declining at equivalent rates while retaining the nucleoprotein > acid polymerase immunodominance hierarchy characteristic of the earlier antigen-driven phase. Lowest levels of the CD69 “activation marker” were detected consistently on virus-specific CD8+ T cells in the blood, then the spleen. Those in the bone marrow and liver were intermediate, and CD69hi T cells were very prominent in the regional lymph nodes and the nasal-associated lymphoid tissue. Any population of “resting” CD8+ memory T cells is thus phenotypically heterogeneous, widely dispersed, and subject to broad homeostatic and local environmental effects irrespective of epitope specificity or magnitude.
Resumo:
On deletion of the gene encoding the constant region of the T cell antigen receptor (TCR)α chain in mature T cells by induced Cre-mediated recombination, the cells lose most of their TCR from the cell surface within 7–10 days, but minute amounts of surface-bound TCRβ chains are retained for long periods of time. In a situation in which cellular influx from the thymus is blocked, TCR-deficient naïve T cells decay over time, the decay rates being faster for CD8+ cells (t1/2 ≈ 16 days) than for CD4+ cells (t1/2 ≈ 46 days). TCR+ naïve cells are either maintained (CD8+) or decay more slowly (CD4+; t1/2 ≈ 78 days.) Numbers of TCR-deficient memory T cells decline very slowly (CD8+ cells; t1/2 ≈ 52 days) or not at all (CD4+ cells), but at the population level, these cells fail to expand as their TCR+ counterparts do. Together with earlier data on T cell maintenance in environments lacking appropriate major histocompatibility complex antigens, these data argue against the possibility that spontaneous ligand-independent signaling by the αβTCR contributes significantly to T-cell homeostasis.
Resumo:
Working memory refers to the ability of the brain to store and manipulate information over brief time periods, ranging from seconds to minutes. As opposed to long-term memory, which is critically dependent upon hippocampal processing, critical substrates for working memory are distributed in a modality-specific fashion throughout cortex. N-methyl-D-aspartate (NMDA) receptors play a crucial role in the initiation of long-term memory. Neurochemical mechanisms underlying the transient memory storage required for working memory, however, remain obscure. Auditory sensory memory, which refers to the ability of the brain to retain transient representations of the physical features (e.g., pitch) of simple auditory stimuli for periods of up to approximately 30 sec, represents one of the simplest components of the brain working memory system. Functioning of the auditory sensory memory system is indexed by the generation of a well-defined event-related potential, termed mismatch negativity (MMN). MMN can thus be used as an objective index of auditory sensory memory functioning and a probe for investigating underlying neurochemical mechanisms. Monkeys generate cortical activity in response to deviant stimuli that closely resembles human MMN. This study uses a combination of intracortical recording and pharmacological micromanipulations in awake monkeys to demonstrate that both competitive and noncompetitive NMDA antagonists block the generation of MMN without affecting prior obligatory activity in primary auditory cortex. These findings suggest that, on a neurophysiological level, MMN represents selective current flow through open, unblocked NMDA channels. Furthermore, they suggest a crucial role of cortical NMDA receptors in the assessment of stimulus familiarity/unfamiliarity, which is a key process underlying working memory performance.
Resumo:
This study evaluated whether T-cell memory reflects increased precursor frequencies of specific long-lived T cells and/or a low-level immune response against some form of persistent antigen. Antivirally protective CD8+ T-cell memory was analyzed mostly in the original vaccinated host to assess the role of antigen in its maintenance. T-cell mediated resistance against reinfection was measured in the spleen and in peripheral solid organs with protocols that excluded protection by antibodies. In vivo protection was compared with detectable cytotoxic T-lymphocyte precursor frequencies determined in vitro. In the spleen, in vitro detectable cytotoxic T-lymphocyte precursor frequencies remained stable independently of antigen, conferring resistance against viral replication in the spleen during reinfection. In contrast, T-cell mediated resistance against reinfection of peripheral solid organs faded away in an antigen-dependent fashion within a few days or weeks. We show that only memory T cells persistently or freshly activated with antigen efficiently extravasate into peripheral organs, where cytotoxic T lymphocytes must be able to exert effector function immediately; both the capacity to extravasate and to rapidly exert effector function critically depend on restimulation by antigen. Our experiments document that the duration of T-cell memory protective against peripheral reinfection depended on the antigen dose used for immunization, was prolonged when additional antigen was provided, and was abrogated after removal of antigen. We conclude that T-cell mediated protective immunity against the usual peripheral routes of reinfection is antigen-dependent.
Resumo:
A fundamental question about memory and cognition concerns how information is acquired about categories and concepts as the result of encounters with specific instances. We describe a profoundly amnesic patient (E.P.) who cannot learn and remember specific instances--i.e., he has no detectable declarative memory. Yet after inspecting a series of 40 training stimuli, he was normal at classifying novel stimuli according to whether they did or did not belong to the same category as the training stimuli. In contrast, he was unable to recognize a single stimulus after it was presented 40 times in succession. These findings demonstrate that the ability to classify novel items, after experience with other items in the same category, is a separate and parallel memory function of the brain, independent of the limbic and diencephalic structures essential for remembering individual stimulus items (declarative memory). Category-level knowledge can be acquired implicitly by cumulating information from multiple training examples in the absence of detectable conscious memory for the examples themselves.
Resumo:
Introdução: A formação dos profissionais da área da saúde é fundamental para a transformação das práticas de cuidado e consolidação dos princípios e diretrizes do Sistema Único de Saúde (SUS). Sendo um desafio do SUS, esta questão também está presente no campo da Saúde Mental e é necessária para a consolidação da Reforma Psiquiátrica e construção e fortalecimento da Rede de Atenção Psicossocial. Proposição: Investigar e refletir sobre as experiências dos estudantes que realizaram estágio no Centro de Atenção Psicossocial (CAPS) III Itaim Bibi entre 2009 e 2014, no tocante à formação profissional em Saúde Mental na perspectiva da Reforma Psiquiátrica. Materiais e Métodos: Estudo qualitativo, com construção dos dados a partir da leitura de relatórios dos estudantes e de questionários com perguntas referentes à experiência dos estágios, que foram apresentadas aos participantes conforme orientações do método Delphi. As questões abordaram: motivos; expectativas; forma e qualidade de participação nas atividades; temas e estudos; trabalho em equipe; situações vivenciadas; influência na atuação profissional; apresentação do estágio e sugestões de alterações. As informações foram trabalhadas por meio de Análise de Conteúdo Temática. Resultados: Dos 52 convidados, 28 participaram da primeira rodada (53,85%), sendo: 14 terapeutas ocupacionais, 9 enfermeiros, 3 psicólogos e 2 estudantes de Serviço Social. O segundo questionário foi composto por afirmativas presentes nas respostas recebidas para que os participantes as avaliassem conforme grau de concordância da escala Likert. Nesta fase foram recebidas 26 respostas. Conclusões: Apesar das dificuldades vivenciadas, avaliou-se que a maior parte das experiências dos estágios foi positiva e possibilitou aprendizagens significativas sobre o modelo de atenção psicossocial, o funcionamento e dinâmica da instituição, o trabalho em equipe interdisciplinar e as produções de convivência, principalmente aos sujeitos que realizaram estágios com maior carga horária. Identificaram como importantes aprendizados as experiências de acompanhamento individual e grupal dos usuários, a construção de Projeto Terapêutico Singular e de redes, o trabalho territorial e intersetorial. A participação em reuniões, supervisões clínico-institucionais, multiprofissionais e em oficinas de reflexão com as docentes das Universidades foi considerada importante para a formação. O aprendizado de manejo de situações de crise e de conflitos e de técnicas de contenção foi considerado superficial. Identificou-se que modelo de gestão e o trabalho da equipe influenciam no desenvolvimento de autonomia e protagonismo dos estagiários. O fortalecimento da integração ensino-serviço-comunidade é necessário e a flexibilização das propostas instituídas poderia facilitar a construção conjunta dos planos de estágios. Como produtos desta pesquisa foram elaboradas propostas de modificações para melhor organização dos estágios no CAPS e para a integração ensino-serviço e de Plano de Estágio Supervisionado em Terapia Ocupacional para os estágios extracurriculares. Realizou-se também uma Revisão Integrativa das publicações científicas brasileiras sobre a formação de estudantes de graduação em Saúde Mental na perspectiva da Reforma Psiquiátrica. Por fim, compreendeu-se que as experiências ressoam nas práticas profissionais dos graduados de modo positivo. Os participantes que não atuam neste campo, disseram levar consigo a experiência do trabalho em equipe e de formas éticas e humanizadas de cuidado.
Resumo:
Subpixel methods increase the accuracy and efficiency of image detectors, processing units, and algorithms and provide very cost-effective systems for object tracking. Published methods achieve resolution increases up to three orders of magnitude. In this Letter, we demonstrate that this limit can be theoretically improved by several orders of magnitude, permitting micropixel and submicropixel accuracies. The necessary condition for movement detection is that one single pixel changes its status. We show that an appropriate target design increases the probability of a pixel change for arbitrarily small shifts, thus increasing the detection accuracy of a tracking system. The proposal does not impose severe restriction on the target nor on the sensor, thus allowing easy experimental implementation.
Resumo:
We have analyzed surface-wave propagation that takes place at the boundary between an isotropic medium and a semi-infinite metal-dielectric periodic medium cut normally to the layers. In the range of frequencies where the periodic medium shows hyperbolic space dispersion, hybridization of surface waves (dyakonons) occurs. At low to moderate frequencies, dyakonons enable tighter confinement near the interface in comparison with pure SPPs. On the other hand, a distinct regime governs dispersion of dyakonons at higher frequencies.
Resumo:
The present paper addresses the analysis of structural vibration transmission in the presence of structural joints. The problem is tackled from a numerical point of view, analyzing some scenarios by using finite element models. The numerical results obtained making use of this process are then compared with those evaluated using the EN 12354 standard vibration reduction index concept. It is shown that, even for the simplest cases, the behavior of a structural joint is complex and evidences the frequency dependence. Comparison with results obtained by empirical formulas reveals that those of the standards cannot accurately reproduce the expected behavior, and thus indicate that alternative complementary calculation procedures are required. A simple methodology to estimate the difference between numerical and standard predictions is here proposed allowing the calculation of an adaptation term that makes both approaches converge. This term was found to be solution-dependent, and thus should be evaluated for each structure.