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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.
11

Caracterização morfológica e funcional de sensila gustativa da quelícera de Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) / The gustatory sensilla chelicerae of Rhipicephalus sanguineus (Latreille, 1806) (Acari: ixodidae)

Soares, Sara Fernandes 29 February 2012 (has links)
Submitted by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-06T16:58:22Z No. of bitstreams: 2 Tese - Sara Fernandes Soares - 2012.pdf: 2842867 bytes, checksum: dff92fa87ddeabaa7f16510a5ac58f11 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-06T17:07:16Z (GMT) No. of bitstreams: 2 Tese - Sara Fernandes Soares - 2012.pdf: 2842867 bytes, checksum: dff92fa87ddeabaa7f16510a5ac58f11 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-06T17:07:16Z (GMT). No. of bitstreams: 2 Tese - Sara Fernandes Soares - 2012.pdf: 2842867 bytes, checksum: dff92fa87ddeabaa7f16510a5ac58f11 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2012-02-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Rhipicephalus sanguineus is an ectoparasite of domestic dogs which can also be found in other mammals, including humans. It has high medical and veterinary importance, given that it can transmit pathogens that cause diseases such as Rocky Mountain spotted fever and Boutonneuse fever in humans and babesiosis and ehrlichiosis in dogs. The main control method to this tick is the use of chemical acaricides which, over the years, has selected resistant tick populations to these products. To develop strategies to control this tick, it is necessary to know its ecology. Electrophysiological techniques are important tools in the study of substances that interfere with the behavior of animals. In this study, the existence of gustatory sensilla on the chelicerae of R. sanguineus was investigated by scanning electron microscopy (SEM). Also, the electrophysiological responses of the neurons present in this sensilla in nonfed ticks to substances with the potential to act as phagostimulant, such as salts (KCl and NaCl), sugars (glucose, sucrose and fructose), the nucleotide adenosine triphosphate (ATP), the tripeptide reduced glutathione (GSH) and two purine (guanine and hypoxanthine) were assessed. Phytoecdysteroids (PES), compounds analogous to ecdysteroids, known as the molting hormones in arthropods, were also tested in electrophysiology. The PES ecdysone (E), 20-hidroxyecdysone (20E), ponasterone A (PonA), makisterone A (MakA), inokosterone (Inok) and Pterosterone (Pte) were tested on nonfed and fed ticks. To evaluate the influence the PEs identified as active in electrophysiology on feeding behavior of R. sanguineus, attachment bioassays in vivo were proceeded. The images obtained with SEM revealed the existence of a pore in the inner digit of the chelicerae, involved in taste perception in these ticks. The results obtained in electrophysiology showed strong activity of R. sanguineus cheliceral neurons to glucose and GSH, at concentrations above 10-4 M, to ATP from 10-2 M, and salts from 10-1 M. The action potentials observed in response to ATP at all used concentrations (from 10-6 M to 10-2 M), and to KCl at 1 M were from different neurons, while the action potentials to the other potentially phagostimulant stimuli were from a single neuron. Considering the responses to PEs in nonfed ticks, MakA and Pte triggered action potentials frequencies greater than the negative control, with detection thresholds of 10-6 M and 10-12 M, respectively. The action potentials amplitudes for these substances as well as for 20E and PonA were higher than those for the control, indicating the activity of a different neuron from that observed for the negative control. In fed ticks, only Pte at 10-4 M remained active. In the behavior assays, there was no difference in attachment between PEs and the control and no interference in the biological parameters was observed. The results obtained in this study showed the ability of R. sanguineus to detect in their cheliceral taste sensilla substances with different natures, as potential phagostimulants and PEs. Further studies in this area are needed to elucidate the role of these substances in the chemical ecology of these ticks. / Rhipicephalus sanguineus é um ectoparasita de cães domésticos, também encontrado em outros mamíferos, inclusive no homem. Tem elevada importância nas medicinas humana e veterinária, podendo transmitir agentes patogênicos causadores de doenças, como as febres botonosa e maculosa em humanos e a babesiose e a erliquiose em cães. Seu controle é feito com o uso de acaricidas químicos, o que, ao longo do tempo, selecionou populações deste carrapato resistentes a estes produtos. Para a elaboração de estratégias de controle deste carrapato é necessário conhecer sua ecologia. Técnicas eletrofisiológicas são ferramentas importantes na identificação de substâncias que interferem no comportamento de animais. Neste trabalho foi investigada a existência de sensilas gustativas nas quelíceras de R. sanguineus por meio da microscopia eletrônica de varredura (MEV). Também se avaliou a resposta eletrofisiológica dos neurônios destas sensilas, em carrapatos não alimentados, a substâncias com potencial para efeito fagoestimulante, tais como sais (KCl e NaCl), açúcares (glicose, sacarose e frutose), o nucleotídeo trifosfato de adenosina (ATP) e o tripeptídeo glutationa reduzida (GSH), assim como purinas (guanina e hipoxantina). Fitoecdisteróides (FES), compostos análogos aos ecdisteróides, conhecidos como hormônios da muda em artrópodes, foram igualmente avaliados pela eletrofisiologia. Foram empregados carrapatos antes e após a alimentação e os seguintes FEs: ecdisona (E), 20-hidroxiecdisona (20E), ponasterona A (PonA), makisterona A (MakA), inokosterona (Inok) e pterosterona (Pte). Para avaliar a interferência, no comportamento de alimentação de R. sanguineus, dos FEs que foram identificados ativos na eletrofisiologia, foram empregados testes de fixação in vivo. As imagens obtidas com a MEV evidenciaram a existência de um poro no dígito interno das quelíceras, envolvido na percepção gustativa, nesses carrapatos. Os resultados obtidos com a eletrofisiologia revelaram forte atividade de neurônios quelicerais de R. sanguineus à glicose e à GSH, em concentrações acima de 10-4 M, ao ATP, a partir de 10-2 M, e aos sais a partir de 10-1 M. Os potenciais de ação observados em resposta ao estímulo com ATP, em todas as concentrações empregadas (de 10-6 M a 10-2 M), e ao KCl a 1 M foram oriundos de diferentes neurônios, enquanto que aos demais estímulos potencialmente fagoestimulantes foram provenientes de um único neurônio. Quanto aos FEs, em carrapatos não alimentados, MakA e Pte desencadearam frequências de potenciais de ação superiores ao controle negativo, com limiares de detecção de 10-6 M e 10-12 M, respectivamente. As amplitudes dos potenciais de ação para estas substâncias bem como para 20E e PonA foram maiores que as do controle, indicando a atividade de um neurônio diferente do observado para o controle negativo. Nos carrapatos após alimentação, somente Pte à 10-4M permaneceu ativa. Nos testes comportamentais, não houve diferença de fixação entre os tratamentos com FEs e com o controle negativo e nem interferência do FEs nos parâmetros biológicos avaliados. Os resultados obtidos no presente estudo evidenciaram a capacidade de R. sanguineus em detectar, em suas sensilas gustativas quelicerais, substâncias de diferentes naturezas, como potenciais fagoestimulantes e FEs. Mais estudos nesta área são necessários visando esclarecer o papel destas substâncias na ecologia química destes carrapatos.
12

A comunicação de más notícias: análise do treinamento de habilidades para profissionais de saúde / Communication of bad news: analysis of skills training for health professionals

Sousa, Fernando Henrique de 15 September 2017 (has links)
Estudo quase experimental, com grupo de intervenção avaliado antes e após o procedimento, com o objetivo de capacitar os profissionais da saúde para as situações de comunicação de más notícias aos pacientes e aos seus familiares, por meio de um curso de difusão gratuito, com duração de cinco horas. Participaram 79 profissionais da saúde, entre enfermeiros, estudantes de enfermagem, biólogos, farmacêuticos, estudantes de medicina, psicólogos, assistentes sociais e terapeutas ocupacionais. Foram utilizados como instrumentos de pesquisas: 1) o questionário Breaking Bad News sobre o protocolo SPIKES, que possui 13 questões objetivas. Este questionário foi analisado pela distribuição da porcentagem de respostas para cada questão; 2) o questionário de avaliação do curso de más notícias composto por 43 questões objetivas. Para a análise das variáveis quantitativas foram utilizadas as médias e as medianas para resumir as informações, e os desvios-padrão, mínimo e máximo, para indicar a variabilidade dos dados, além da porcentagem. A comparação entre as pontuações dos participantes na primeira e na segunda avaliação de habilidades de comunicação foi realizada pelo teste estatístico de McNemar. O teste estatístico não paramétrico Mann-Whitney foi utilizado para comparar a relação entre a idade dos participantes e as respostas do questionário de avaliação do curso de más notícias. A comparação entre a idade e a pontuação total dos participantes na avaliação de conteúdo do curso foi feita pelo coeficiente de correlação de Spearman. Para todos os testes assumiu-se o nível de significância em 5%. A idade dos participantes variou entre 18 e 55 anos, sendo a maioria do sexo feminino (83,5%) e da área da enfermagem (53,2% profissionais e 24,1% estudantes). Ademais, 57% dos participantes nunca tiveram qualquer formação sobre transmissão de más notícias, porém mesmo após este curso, oito pessoas continuaram afirmando que não tiveram formação alguma. A autoavaliação da capacidade de informar uma má notícia no pré-teste foi considerada boa por 18,2%; 20,8% consideraram-se ruins e 6,5%, péssimos, enquanto que o pós-teste 42,8% consideraram-se bons, 11,7%, ruins e 2,6%, péssimos. O conforto do profissional neste momento variou de 21,8% para 7,7% no item absolutamente desconfortável, e de 6,4% para 14,1% no item confortável. Após o conhecimento sobre o protocolo SPIKES, 92,3% acreditam em sua aplicabilidade na prática clínica.Quanto à estratégia utilizada pelos entrevistados em sua prática clínica, o item mostrou que \"um plano ou estratégia consistente\" apresentou frequências de 21,9% no pré-teste e 51,56% no pós-teste. Os elementos do protocolo SPIKES apontados como de maiores facilidades entre os participantes no pré-teste foi o local da notícia e a verificação da compreensão de tudo o que foi dito, 30,6% e 28,6%, ao passo que no pós-teste o item mais escolhido foi a escolha do ambiente (53,06%). A relação entre idade e conhecimento do protocolo SPIKES teve apenas um item que apresentou significância. Concluiu-se, portanto, que o treinamento de habilidades de comunicação de más notícias atingiu seus objetivos melhorando o conhecimento e a aptidão dos profissionais da saúde. Evidenciou-se também que a educação em comunicação na área da saúde mantém-se falha, bem como é escassa a difusão de protocolos que abarquem esta difícil tarefa destinada aos profissionais da saúde. O pós-teste mostrar-se-ia mais eficaz caso fosse aplicado após o retorno dos profissionais aos seus pacientes e o uso das técnicas apreendidas. Sugerimos a adoção de educação permanente aos atuantes na área da saúde / A quasi-experimental study with an intervention group evaluated before and after the procedure, in order to enable health professionals to communicate bad news to patients and their families through a free course of five hours duration. We evaluated 79 health professionals, including nurses, nursing students, biologists, pharmacists, medical students, psychologists, social workers and occupational therapists. The following research tools were used: 1) the Breaking Bad News questionnaire about the SPIKES protocol, which has 13 objective questions. This questionnaire was analyzed by the distribution of the percentage of answers for each question; 2) the evaluation questionnaire of the course of bad news composed by 43 objective questions. For the quantitative analysis we used the means and the medians to summarize the information, and the standard deviations, minimum and maximum to indicate the variability of the data, besides the percentage. The comparison between the scores of participants in the first and second evaluation of communication skills was performed by the McNemar statistical test. The Mann-Whitney non-parametric statistical test was used to compare the relationship between the age of the participants and the responses of the evaluation questionnaire of the course of bad news. The comparison between the age and the total score of the participants in the evaluation of course content was made by the Spearman correlation coefficient. For all tests, the level of significance was set at 5%. The participants\' ages ranged from 18 to 55 years old, with most females (83.5%) and nursing (53.2% professionals and 24.1% students). In addition, 57% of the participants never had any training on the transmission of bad news, but even after this course, eight people continued to claim that they had no training. The self-reported ability to report bad news in the pre-test was considered good by 18.2%; 20.8% were considered bad and 6.5% were poor, while the post-test 42.8% were considered good, 11.7%, bad and 2.6% Lousy. The comfort of the professional at the time ranged from 21.8% to 7.7% on the uncomfortable item and from 6.4% to 14.1% on the comfortable item. After knowing about the SPIKES protocol, 92.3% believe in its applicability in clinical practice. Regarding the strategy used by the interviewees in their clinical practice, the item showed that \"a consistent plan or strategy\" presented frequencies of 21.9% in the pre-test and 51.56% in the post-test. The elements of the SPIKES protocol identified as greatest facilities among participants in the pre-test were the news site and the verification of the understanding of all that was said 30.6% and 28.6%, while in the post-test the most chosen item was the choice of the environment (53.06%). The relationship between age and knowledge of the SPIKES protocol had only one item that presented significance. It was concluded, therefore, that communication education in the health area remains flawed, as well as the dissemination of protocols that cover this difficult task for health professionals. The post-test would be more effective if it were applied after the return of the professionals to their patients and the use of the seized techniques. We suggest the adoption of permanent education to those in the health area
13

Um estudo sobre a detecção de spikes em sinais neuronais

Castellani, Renato Aguiar January 2014 (has links)
Orientador: Prof. Dr. Marcio Eisencraft / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia da Informação, 2014. / Efficient techniques for analysis of neuronal signals in intracranial data acquisition systems are almost prerequisites for the observation of specific brain regions for controlled stimulation,either for medical purposes or for human-computer interaction. The spike sorting, which aimsto classify firings per neuron, is relevant to simplify the analysis of noisy neuronal signalsthat possess a significant amount of information. Detection is the first step of the spikesorting and is decisive in terms of efficiency. In this case, what makes the detection problemrather difficult is the fact that we do not know exactly the waveform of the signal to bedetected and the firing instants. In the present work, the limits of detection techniques based on threshold are studied considering a simplified model of neuronal signals. The techniques are evaluated using error probability measures as a function of the signal-to-noiseratio (SNR), of the firing rate and of the threshold level used. The objective is to combine theadvantages and limits of good performance of detection techniques with the characteristicsof different time series considered. Computational simulations suggest that: (i)the SNR andthe interval between firings significantly affect the relative performance of the techniques;(ii) the optimal threshold is a function of the statistical characteristics of the time seriesand, if properly chosen, can avoid detection errors in some situations and (iii) the thresholdcalculations proposed in the literature may not be the most effective. The results of thesimplified model should serve as an estimate of the worst case performance for each methodwhen they are applied in situations with acquired real data.
14

Point process modeling as a framework to dissociate intrinsic and extrinsic components in neural systems

Fiddyment, Grant Michael 03 November 2016 (has links)
Understanding the factors shaping neuronal spiking is a central problem in neuroscience. Neurons may have complicated sensitivity and, often, are embedded in dynamic networks whose ongoing activity may influence their likelihood of spiking. One approach to characterizing neuronal spiking is the point process generalized linear model (GLM), which decomposes spike probability into explicit factors. This model represents a higher level of abstraction than biophysical models, such as Hodgkin-Huxley, but benefits from principled approaches for estimation and validation. Here we address how to infer factors affecting neuronal spiking in different types of neural systems. We first extend the point process GLM, most commonly used to analyze single neurons, to model population-level voltage discharges recorded during human seizures. Both GLMs and descriptive measures reveal rhythmic bursting and directional wave propagation. However, we show that GLM estimates account for covariance between these features in a way that pairwise measures do not. Failure to account for this covariance leads to confounded results. We interpret the GLM results to speculate the mechanisms of seizure and suggest new therapies. The second chapter highlights flexibility of the GLM. We use this single framework to analyze enhancement, a statistical phenomenon, in three distinct systems. Here we define the enhancement score, a simple measure of shared information between spike factors in a GLM. We demonstrate how to estimate the score, including confidence intervals, using simulated data. In real data, we find that enhancement occurs prominently during human seizure, while redundancy tends to occur in mouse auditory networks. We discuss implications for physiology, particularly during seizure. In the third part of this thesis, we apply point process modeling to spike trains recorded from single units in vitro under external stimulation. We re-parameterize models in a low-dimensional and physically interpretable way; namely, we represent their effects in principal component space. We show that this approach successfully separates the neurons observed in vitro into different classes consistent with their gene expression profiles. Taken together, this work contributes a statistical framework for analyzing neuronal spike trains and demonstrates how it can be applied to create new insights into clinical and experimental data sets.
15

Experimental Evaluation of Full Scale I-Section Reinforced Concrete Beams with CFRP-Shear Reinforcement

Aquino, Christian 01 January 2008 (has links)
Fiber reinforced polymer (FRP) systems have shown great promise in strengthening reinforced concrete structures. These systems are a viable option for use as external reinforcement because of their light weight, resistance to corrosion, and high strength. These systems, externally bonded in the form of sheets or laminates, have shown to increase the flexural and more recently the shear capacity of members. Major concerns of the system are issues related to the bond strength and premature peeling especially when reentrant corners are present. The objectives of this study were to verify the effectiveness of carbon FRP (CFRP) laminates on an I-section beam with no anchorage and to determine the feasibility of using an anchorage system to prevent premature debonding. The two types of anchorage systems used were a horizontal CFRP laminate and glass FRP (GFRP) spikes. These anchorage systems verified that the use of anchorage on I-shaped beams can prevent premature debonding of the laminate and allow the specimens to achieve a higher shear capacity. Recommendations for future research of such systems are also presented.
16

Characterisation of the Sydney region in relation to corrosion, timber decay risk factors and the corrosion of nails in timber in covered conditions /

McGeachie, Mark Thomas. January 2001 (has links)
Thesis (Ph.D.) -- University of Western Sydney, 2001. / Bibliography : leaves 201-208.
17

The effect of biological deterioration on the performance of nailed oriented strand board sheathing to Douglas-fir framing member connections /

Kent, Scott M. January 2004 (has links)
Thesis (Ph. D.)--Oregon State University, 2004. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.
18

Essays on Australian wholesale electricity price spikes and the Australian pre-dispatch process

Zainudin, Wan Nur Rahini Aznie Binti January 2014 (has links)
In the first essay I examine whether the occurrences of the extreme price events display any regularities that can be captured using an econometric model. Here I treat these price events as point processes and apply Hawkes and Poisson autoregressive models to model the dynamics in the intensity of this process. I use load and meteorological information to model the time variation in the intensity of the process. The models are applied to data from the Australian wholesale electricity market, and a forecasting exercise illustrates both the usefulness of these models and their limitations when attempting to forecast the occurrence of extreme price events. In the second essays I explain that in the past doubts have been raised as to whether the pre-dispatch process in Australia Electricity Market is able to give market participants and market operator good and timely quantity and price information. It is the purpose of the second essay to introduce a framework to analyse whether the pre-dispatch process is delivering biased predictions of the actual wholesale spot price outcomes. Here I investigate the bias by comparing the actual wholesale market spot price outcome to pre-dispatch sensitivity prices established the day before dispatch and on the day of dispatch. I observe a significant bias (mainly indicating that the pre-dispatch process tends to underestimate spot price outcomes) and I further establish the seasonality features of the bias across seasons and/or trading periods. I also establish changes in bias across the years in our sample period (1999 to 2007). In the formal setting of an ordered probit model I establish that there are some exogenous variables that are able to explain increased probabilities of over- or under-predictions of the spot price. It transpires that meteorological data, expected pre-dispatch prices and information on past over- and under-predictions contribute significantly to explaining variation in the probabilities for over- and under-predictions. The results allow me to conjecture that some of the bids and re-bids provided by electricity generators are not made in good faith. Finally, the third essay investigates whether information from this pre-dispatch process can be useful when predicting next-day price spikes. In a preliminary analysis I establish the effect of pre-dispatch prices on the quantiles of the spot price distribution. A Quantile regression approach reveals that higher pre-dispatch prices signal only to a certain extent an increased probability of higher spot price outcomes. They also signal a higher uncertainty about the resulting spot price outcomes. I further establish whether the inclusion of information from the pre-dispatch process can significantly improve the predictability of price spikes when these are modelled as a point process (as in the first essay). The models used here are Hawkes and Poisson autoregressive models which allow for time variation (correlated to exogenous information) in the intensity process that governs the occurrence of price spikes. It transpires that the pre-dispatch process of the Australian Electricity Market does not provide any information that can be used in a systematic manner to help predicting on what days price spikes are more likely to occur.
19

Single shear vs. double shear for nails in lateral loading

Stoneburner, Paul W. January 1952 (has links)
Tests were conducted on three-member southern pine joints to determine (1) the relationship of the lateral load-carrying capacity of nails in single and double shear, and (2) to develop a basis for structural design data for laterally loaded nails in double shear applicable whenever deformation is a governing factor, such as in joints of trussed rafters. The test loads at or near proportional limit show that low-carbon-steel plain-shank and helically threaded Screwtite nails loaded in double shear carry twice the single-shear loads; while hardened high-carbon-steel plain-shank and Screwtite nails loaded in double shear carry considerably less than twice the single-shear loads. If these relationships between single-shear and double-shear loads are to be valid, the nail must be optimum diameter tor the joint. Structural design data as based on test loads at or near proportional limit for laterally loaded low-carbon-steel plain-shank nails in single and double shear are applicable to low-carbon-steel Screwtite nails and to same-length, smaller-diameter, hardened high-carbon-steel plain-shank and Screwtite nails. This finding, however, is not valid if consideration is to be given to the load-carrying capacity beyond proportional limit and at ultimate, to the influence or exposure on nail-holding power, and to certain advantage resulting from the use of threaded-shank as well as hardened nails. Design data as advanced in the National Design Specification for low-carbon-steel plain-shank nails in single shear are verified within their scope. Additional information is presented on the performance or plain-shank nails, Screwtite nails, and Stronghold Screwnails under given conditions, on the effects or pre-boring and clinching, and on the efficiency or toothed-ring Burrlock fasteners as reinforcement for nailed lumber joints. / M.S.
20

Τοπογραφική αξιολόγηση εντοπιστικής ικανότητας εξωκρανιακού ΗΕΓ σε βλάβες κροταφικού λωβού με εξωκροταφική εντόπιση

Γιαννικοπούλου, Φωτεινή 06 December 2013 (has links)
Η παρούσα διπλωματική εργασία ασχολείται με τον προεγχειρητικό έλεγχο ασθενών με κροταφική επιληψία που είναι υποψήφιοι να χειρουργηθούν. Συγκεκριμένα εστιάζει στην αξιολόγηση της χρήσης του εξωκρανιακού ΗΕΓ (ηλεκτροεγκεφαλογραφήματος) ως προεγχειρητικού συνεπικουρικού εργαλείου για την εντόπιση και χαρτογράφηση της βλάβης του κροταφικού λοβου για ένα άριστο μετεγχειρητικό αποτέλεσμα. / This study focuses on the preoperative evaluation of extracranial EEG of patients with temporal lobe epilepsy who are candidates for surgery. More precisely, it focuses on the efficiency of the extracranial EEG to map the intracranial lesion that causes the epileptic syndrome.

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