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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

O tutor presencial e a mediação na educação a distância na UFJF: papéis e atribuições

Ribeiro, Rodrigo Gonçalves 30 June 2016 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-01-10T16:31:04Z No. of bitstreams: 1 rodrigogoncalvesribeiro.pdf: 1447845 bytes, checksum: 034bc7083f25c26990e9608570be3c96 (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2017-01-31T11:20:09Z (GMT) No. of bitstreams: 1 rodrigogoncalvesribeiro.pdf: 1447845 bytes, checksum: 034bc7083f25c26990e9608570be3c96 (MD5) / Made available in DSpace on 2017-01-31T11:20:09Z (GMT). No. of bitstreams: 1 rodrigogoncalvesribeiro.pdf: 1447845 bytes, checksum: 034bc7083f25c26990e9608570be3c96 (MD5) Previous issue date: 2016-06-30 / A presente dissertação objetiva descrever e analisar a importância da potencialização do papel do tutor presencial no âmbito dos cursos de educação a distância da Universidade Federal de Juiz de Fora. A análise está centrada nas atribuições do profissional de tutoria presencial do curso de Administração Pública, comparado aos profissionais dos cursos de Licenciatura em Computação e Pedagogia. A proposta busca criar um Plano de Ação Educacional (PAE), com as reais atribuições que devem nortear o trabalho deste profissional, com vistas à potencialização do trabalho, observadas as demandas desta modalidade, para compreender suas relações, em especial no curso de Administração Pública, do Programa Nacional de Formação em Administração Pública. Para isto, foram aplicados instrumentos de pesquisa semiestruturada de profundidade aos coordenadores e tutores presenciais do curso de Administração Pública, Licenciatura em Computação e Pedagogia da UFJF, com o fim de obter dados sobre o desenvolvimento da tutoria, tendo em vista a mudança de perfil dos alunos e consequentemente do polo presencial. O primeiro capítulo apresenta inicialmente o problema, ratificado por uma pesquisa preliminar semiestruturada com os coordenadores de polo e do curso de Administração Pública. No segundo capítulo, foram analisados os dados obtidos com os eixos norteadores, identificados pelo Desenho do curso e Mediação. E, por fim, o terceiro capítulo propõe-se a potencialização do trabalho dos tutores presenciais, a partir da mudança do formato atual de trabalho, por meio de mudanças na forma de atuação do tutor, devidamente descritas no Projeto Político Pedagógico do curso de Administração Pública, bem como a construção de um manual e maiores formas de interação entre a equipe multiprofissional. / This dissertation aims to describe and analyze the importance of potentiation - the role of the on-campus tutor encompassing the distance learning undergraduate courses of the Federal University of Juiz de Fora. The analysis is focused on the professional duties of on-campus tutoring in the undergraduate course of Public Administration, compared to professionals in the undergraduate courses in Computer Science and in Education. The proposal seeks to create an Educational Action Plan (PAE, in Portuguese), with the actual tasks that should guide the work of this professional, so as to potentiate the work, observing to the demands of this educational category, to understand their relations, especially in the course of Public Administration, the National Programme for Training in Public Administration. To that end, research tools were applied of deep semistructured research to coordinators and on-campus tutors of the courses of Public Administration, Computer Science and Education at UFJF, in order to obtain data on the development of tutoring, so as to change the student profile and consequently the on-campus site. The first chapter presents the problem initially, ratified by preliminary semistructured research with site coordinators and head of the Public Administration undergraduate course. In the second chapter, the data obtained was analyzed with the guiding principles identified by the course design and mediation. And finally, the third chapter proposes the enhancement of the work of the on-campus tutors from changing the current format of work, by means of changes role of the tutor, properly described in the Pedagogical political Project of the Public Administration undergraduate course as well as the construction of a textbook and greater forms of interaction between the multidisciplinary team.
52

VISUALIZING NANO-SCALE SYNAPTIC CHANGES DURING SINGLE DENDRITIC SPINE LONG-TERM POTENTIATION BY CORRELATIVE LIGHT AND ELECTRON MICROSCOPY

Unknown Date (has links)
Dendritic spines are the major sites for receiving excitatory synaptic inputs and play important roles in neuronal signal transduction, memory storage and neuronal circuit organization. Structural plasticity of dendritic spines is correlated with functional plasticity, and is critical for learning and memory. Visualization of the changes of dendritic spines at the ultrastructural level that specifically correlated with their function changes in high throughput would shed light on detailed mechanisms of synaptic plasticity. Here we developed a correlative light and electron microscopy workflow which combines two-photon MNI-glutamate uncaging, pre-embedding immunolabeling, Automatic Tape-collecting Ultramicrotome sectioning and scanning electron microscopy imaging. This method bridges two different visualization platforms, directly linking ultrastructure and function at the level of individual synapses. With this method, we successfully relocated single dendritic spines that underwent long-term potentiation (LTP) induced by two-photon MNI-glutamate uncaging, and visualized their ultrastructures and AMPA receptors distribution at different phases of LTP in high throughput. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection
53

The Effects of Different Set Configurations on Concentric Velocities in the Barbell Back Squat

Wong, Hanson 01 August 2020 (has links)
The purpose of this study was to determine if concentric velocities of lighter loads of could be augmented if they are performed heavier working sets. Twelve trained males with experience in the barbell back squat performed a 5RM and completed two separate squat training session conditions that consisted of three sets of five repetitions with 85% of their 5RM. Both conditions differed in the placement of a reduced-load set that was either performed after the working sets or during the warm-up period. No significant differences were observed in the working set MCVs in both conditions. Additionally, no significant differences were observed amongst MCVs in the Down Set and equivalent warm-up set loads. The results of this study suggest that postactivation potentiation may not occur using a similar set-load scheme.
54

Implementing of Phase Potentiation Program with College Triathletes

Fish, David 01 August 2021 (has links)
The purpose of this study is to determine the effectiveness of an in-season resistance training program on improving measures of strength in female collegiate triathletes. Nine females (age = 19.2 ± 1.1 years, height = 166.5 ± 12.5 cm, body mass = 61.1 ± 9 kg) with limited resistance training experience were examined for this study. Formal RT intervention was monitored for 7 weeks with the athletes being assigned 6 weeks of independent RT prior to the pre-test. Athletes completed a standardized athlete monitoring program pre and post resistance training intervention. Paired sample t-tests were used to determine differences between conditions with Cohen’s d effect sizes describing the magnitude of change between pre and post-intervention. No significant changes were found between the two testing sessions (p > 0.05). A longer duration of utilizing resistance training adhering to a phase potentiated approach may be necessary for significant changes to occur.
55

Lokální a globální efekt sub-maximálního dřepu na post-aktivační zvýšení výstupního svalového výkonu / Local and global effect of sub-maximal squat on post-activation enhancement of muscle power output

Kolinger, Dominik January 2021 (has links)
Title: Local and global effect of sub-maximal squat on post-activation enhancement of muscle power output. Objectives: The aim of this thesis is to determine whether the phenomenon of post-activation performance enhancement (PAPE) manifests locally or globally in terms of improved muscle power output. That is, to determine whether activation of a complex muscle chain will lead to improvements in the muscle power output of other muscle groups and muscle groups included in the activated muscle chain. In this way, to indicate the relationship between global and local physiological mechanisms causing PAPE. Methods: The quasi-experimental method and the method of analysis were used in this work. Eleven basketball players aged 18-28 years completed two measurements in random order. The measurements started with a non-specific warm-up followed by a pre- activation test (pre-CA) to obtain baseline values. Next, the players performed a specific warm-up and activation exercise (CA) in the form of a squat with an intensity of 2 × 4 × 90 % of one repetition maximum (OM) with a rest interval of 3 min. After the activation exercise, post-CA values were measured at minutes 5, 8 and 11 on force plates and at minutes 6, 9 and 12 on an isokinetic dynamometer (IKD). Pre-CA and post-CA test of the protocol one...
56

Variable Modulation of Inputs to GABA Cells in the Ventral Tegmental Area and Hippocampus

Nufer, Teresa Marie 01 June 2018 (has links)
The ventral tegmental area (VTA) is an important component of the mesolimbic dopamine circuit and processes reward and motivational behaviors. In response to drug exposure, synaptic connections of this circuit can be rewired via synaptic plasticity—a phenomenon thought be responsible for the pathology of addiction. While much is known about dopamine neuron plasticity, less is known regarding plasticity exhibited by VTA GABA cells, specifically inhibitory inputs from outside the VTA. Expanding on the work of Bocklisch et al. (2013), we investigated the plasticity of inhibitory inputs to VTA GABA neurons. Using whole cell electrophysiology in GAD67 GFP mice, we observed that these VTA GABA cells can experience either long-term potentiation (LTP) or long-term depression (LTD) in response to a 5 Hz stimulus. While neither the LTP nor LTD appear to be mediated by the cannabinoid-1 receptor (CB1), the nitric oxide synthase (NOS) pathway, or the dopamine-2 (D2) receptor, the LTP is blocked by APV, an NMDA receptor antagonist, and the LTD is blocked by CGP 54626, an antagonist of the GABAB receptor. Additionally, µ-opioid and adenosine-1 receptors modulated plasticity at this synapse, but chronic morphine administration (10mg/kg) did not block the observed LTP or LTD. Furthermore, we used an optogenetic approach in VGAT-Cre mice to target inhibitory inputs from the lateral hypothalamus (LH) to the VTA. An optical stimulus (5 Hz) caused these inputs to depress, which has not been previously described and may be behaviorally important in reward processing. These novel findings increase our understanding of VTA neural circuitry, ultimately increasing our capacity to better comprehend and treat the pathology of addiction. Additionally, changes in synaptic strength in hippocampal CA1 pyramidal cells are thought to be responsible for the acquisition and retention of short-term memory. Feedforward stratum radiatum interneurons of many subtypes experience LTD, short-term depression (STD), or lack of plasticity, but it is not known whether plasticity correlates with specific interneuron subtypes. Using whole cell electrophysiology and qPCR, we characterized the plasticity expressed by hippocampal interneurons in correlation with their mRNA expression patterns to determine cell subtype. We also assessed the expression of endocannabinoid (eCB) biosynthetic enzymes as well as metabotropic glutamate receptor subunits known to mediate plasticity. Cells exhibiting LTD tended to express mRNA for at least one of the eCB biosynthetic enzymes and the metabotropic glutamate receptor subunit mGluR5. mGluR5 was not expressed by cells exhibiting STD or no plasticity. Cells that exhibited short-term depression tended to express mRNA for at least one of the eCB biosynthetic enzymes, but not mGluR5. This suggests that stratum radiatum interneuron plasticity can be predicted based on mGluR expression, and that these different types of plasticity may have some importance in hippocampal function.
57

Investigation of the Determinants of Agonism In a Ligand-Gated Ion Channel Using Statistical Coupling Analysis

Slobodyanyuk, Mykhaylo 11 June 2021 (has links)
The prokaryotic Erwinia chrysanthemi ligand-gated ion channel (ELIC) is competitively inhibited by acetylcholine (Pan et al., 2012). Acetylcholine is the native agonist of the structurally related family of eukaryotic acetylcholine receptors, which like ELIC are pentameric ligand-gated ion channels. To understand the opposite effect upon acetylcholine binding between ELIC and acetylcholine receptors, we used statistical coupling analysis to predict mutations necessary for installing acetylcholine agonism into ELIC. Statistical coupling analysis was performed on the acetylcholine binding protein from Lymnaea stagnalis. This protein is a structural surrogate for the agonist binding domain of acetylcholine receptors, for which a high-resolution structure in complex with acetylcholine is available. Our analysis identified a group of statistically coupled residues that comprises several amino acids previously implicated in acetylcholine agonism of acetylcholine receptors. Mapping these residues onto ELIC revealed 15 residue discrepancies, 4 of which were chosen for initial mutagenesis based upon their proximity to the known agonist binding site. Electrophysiological characterization of ELIC mutants indicates that the potency of the native agonist, cysteamine, is decreased, highlighting the optimized role wild-type residues serve in native agonism. None of the mutants were activated by acetylcholine, however the double mutant A75D/F133W abolished competitive antagonism by acetylcholine, and instead led to acetylcholine dependent potentiation of cysteamine-induced currents. This work demonstrates the ability of statistical coupling analysis to identify functionally important residues in pentameric ligand-gated ion channels and reveals that acetylcholine can be converted from a competitive antagonist into a potentiator, by installing two residues present in acetylcholine receptors.
58

Genetic Ablation of the Platelet Activating Factor Receptor Does Not Impair Learning and Memory in Wild-Type Mice or Alter Amyloid Plaque Number in a Transgenic Model of Alzheimer’s Disease

Peshdary, Vian January 2012 (has links)
We have recently established that aberrant alkylacylglycerophosphocholine metabolism results in the increased tissue concentration of platelet activating factors (PAFs) in the temporal cortex of Alzheimer Disease (AD) patients and in TgCRND8 mice over-expressing mutant human amyloid precursor protein. PAF lipids activate a G-protein coupled receptor (PAFR) reported to be expressed by microglia and subsets of neurons in rat. It is not known whether this same expression pattern is recapitulated in mice however, as the expression has only been inferred by use of pharmacological PAFR antagonists, many of which impact on both PAFR-dependent and PAFR-independent signalling pathways. PAFR plays a role in long term potentiation (LTP) induction in rats. PAFR has also been implicated in behavioural indices of spatial learning and memory in rats. Contradictory reports using mice provide ambiguity regarding the role of PAFR in LTP induction in mice. To assess whether PAFR is expressed in murine neurons, I localized PAFR mRNA in wild-type C57BL/6 mice using PAFR KO mice as a negative control. I further showed that the loss of PAFR did not impair learning and memory although this assessment must be considered preliminary as the behavioural test employed was not optimized to detect changes in learning and memory of C57BL/6 mice over time adequately.Finally, I showed that the loss of PAFR in TgCRND8 mouse model of AD had no impact upon Aβ plaque number. My observations suggest that PAFR is restricted to microglial-like cells in mouse hippocampus and as such, it may not play a role in learning and memory.
59

[pt] A EXPRESSÃO ZERO ELEVADO A ZERO / [en] THE EXPRESSION ZERO TO THE POWER OF ZERO

25 September 2020 (has links)
[pt] Este trabalho é um estudo sobre a controvérsia que circunda a expressão zero elevado a zero. Como o objetivo de contextualizar o foco principal do trabalho é apresentado um percurso histórico sobre as questões que sustentam a referida controvérsia desde o século XVIII com Leonhard Euler até a atualidade. O texto contém análises exemplificadas em contextos diversos sobre a expressão e apresenta diferentes métodos para a operação potenciação que está estritamente relacionada ao conflito exposto. Também exibe soluções diversas obtidas para o valor da expressão 0 (0) por softwares matemáticos e expõe possíveis métodos de abordagens teóricas que sustentam as soluções que caracterizam a controvérsia. Ao final, é realizada uma análise de como alguns livros didáticos brasileiros abordam a referida expressão. O objetivo deste estudo e das reflexões contidas neste trabalho é permitir aos leitores, estudantes e professores, constatarem que a matemática é rica em detalhes e que o valor de uma simples operação aritmética pode não ter resposta única caso o contexto não esteja bem definido. / [en] This work is a study on the controversy surrounding the expression zero raised to zero. As the objective of contextualizing the main focus of the work is presented a historical journey on the issues that support this controversy since the eighteenth century with Leonhard Euler until today. The text contains analyzes exemplified in different contexts about expression and presents different methods for the potentiation operation that is strictly related to the exposed conflict. It also shows various solutions obtained for the value of the expression 0 (0) by mathematical software and exposes possible methods of theoretical approaches that support the solutions that characterize the controversy. At the end, an analysis is made of how some Brazilian textbooks approach this expression. The objective of this study and the reflections contained in this work is to allow readers, students and teachers, to see that mathematics is rich in details and that the value of a simple arithmetic operation may not have a single answer if the context is not well defined.
60

The Effects of Ketones on Brain Metabolism and Cognition

Saito, Erin Reiko 10 July 2023 (has links) (PDF)
The brain is one of the most energetically demanding organs within the human body and is cognitively susceptible to energetic deficits such that the rise in obesity, insulin resistance, and Alzheimer’s disease in recent decades pose a substantial threat to cognitive longevity. The therapeutic efficacy of ketones are well-established in epilepsy and are currently being applied to other disease states. Alzheimer’s disease is characterized by impairments in brain glucose uptake and metabolism in regions relevant to learning, memory, and cognition that progress with the disease. While brain glucose uptake is impaired, ketone uptake is unaltered, potentially enabling ketones to fuel the glucose-deficient brain. Using RNA-seq data acquired from multiple publicly available AD databases, we assessed glycolytic and ketolytic gene expression in post-mortem AD and cognitively normal control brains. Gene expression was normalized to brain region – parietal lobe, cerebellum, temporal cortex, frontal lobe, inferior frontal gyrus, parahippocampal gyrus, superior temporal gyrus – and cell type – neurons, astrocytes, oligodendrocytes, and microglia. We report impairments in glycolytic gene expression in regions of the brain relevant to memory and cognition in neurons and oligodendrocytes, but not ketolytic gene expression in neurons. The data are consistent with previous work and support clinical ketone intervention. The cognitive effects of ketogenic diets remain controversial, especially in healthy adults. To elucidate the effects of a ketogenic diet in healthy mice, C57BL6 mice were placed on a ketone-supplemented ketogenic diet for eight weeks. Recognition memory was assessed in a novel object recognition test and hippocampal bioenergetics were measured using high-resolution respirometry, western blot, and biochemical assays. The diet significantly improved recognition memory and enhanced hippocampal mitochondrial efficiency, measured by ATP production per unit of oxygen consumed, suggesting cognitive validity of the diet in middle-age. Long-term potentiation (LTP), the activity-dependent strengthening of synapses, within the hippocampus, is one of the molecular mechanisms of learning and memory formation. LTP of hippocampal Schaffer-collaterals was quantified in young adult C57BL/6 mice with field electrophysiology following ex vivo brain slice incubation with a β-hydroxybutyrate-rich ACSF. Mice were then placed on the ketone-supplemented diet for four weeks. Behavioral spatial memory was measured in the Morris water maze and Schaffer-collateral LTP was assessed with field electrophysiology. No meaningful changes in LTP and behavioral memory were observed with ketone treatment, suggesting ketogenic interventions may be more applicable in aging and pathologies that display cognitive deficits, rather than in healthy young adults. Together, these studies support the exploration of ketogenic interventions as a potential restorative measure in Alzheimer’s disease and preventative measure in aging, which may be impactful facing the rise of obesity and insulin resistance.

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