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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

Automatické rozměření signálů EKG / Automatic delineation of ECG signals

Vítek, Martin January 2011 (has links)
This dissertation deals with QRS complex detection and ECG delineation. The theoretical part of the work describes basics of electrocardiography, QRS detection approaches, ECG delineation approaches, the standard CSE database and the wavelet transform theory. The practical part of the work describes designed methods of QRS complex detection and ECG delineation. The designed methods are based on a continuous wavelet transform, appropriate scales, appropriate mother wavelet, cluster analysis and leads transformation. The introduced algorithms were evaluated on the standard CSE database. The obtained results are better, than directly comparable results of other methods and accomplished given database criteria. The robustness of designed algorithms was successfully tested on CSE database signals modified by compression and filtering. The proposed ECG delineation algorithm was successfully used as a tool for evaluation of diagnostic distortion of ECG signals modified by compression.
12

Vlnková filtrace elektrokardiogramů / Wavelet Based Filtering of Electrocardiograms

Smital, Lukáš January 2013 (has links)
This dissertation deals with possibilities of using wavelet transforms for elimination of broadband muscle noise in ECG signals. In this work, the characteristics of ECG signals and particularly the most frequently occurring type of interference are discussed firstly. The theory of wavelet transforms is also introduced and followed by design of the simple wavelet filter and the more sophisticated version with wiener filtering of wavelet coefficients. Next part is devoted to the design of our filter, which is based on wavelet wiener filtering and is complemented by algorithms that ensure full adaptability of its parameters when the properties of the input signal are changing. Suitable parameters of the proposed system are searched automatically and the algorithm is tested on the complete standard electrocardiograms database CSE, where it achieves significantly better results than other published methods.
13

Personlighet, datorerfarenhet och upplevelseav datorfrustration

Hedberg, Maria January 2006 (has links)
I och med informationsteknologins snabba framväxt i samhället ställs vi också inför problem som hur vi ska handskas med denna utveckling. Forskning visar att fenomenet datorrädsla kan bero på faktorer som exempelvis erfarenhet, personlighet, attityd eller kön. Syftet med denna studie är dock att undersöka eventuella samband mellan datorrädsla, personlighet samt datorerfarenhet. Nittio studenter vid Högskolan Dalarna agerade undersökningsdeltagare (UD) genom att svara på en enkät bestående av tre delar; bakgrundsfrågor, ett personlighetstest sammansatt av Eysenck Personality Inventory (EPI) samt åtta scenarier, där UD fick skatta sin självupplevda stressnivå i olika situationer. Studien visar att såväl neuroticism som datorerfarenhet skulle kunna predicera datorrädsla. Starkast effekt på den självskattade stressnivån hade dock variabeln kön. Man kan även dra slutsatsen att fenomenet datorrädsla inte är en specifik slags rädsla, utan till viss del hänger samman med andra fobier.
14

Training Evaluation Investigating Core Self-Evaluations and Perceptions of Training Transfer

Patterson, Thomas P 01 July 2015 (has links)
Although training evaluation is understood as an important way of determining the effectiveness of a training program, additional research in the area of training transfer and core self-evaluations (CSE) could provide insight on measuring the effectiveness of training programs. Training transfer differences and CSE were examined in training courses offered in a workforce development program. The goals of the study were to: (1) evaluate the validity of using CSE as a means of predicting perceptions of transfer, (2) test the previous findings that utility reactions measures are a stronger predictor of transfer than affective reactions measures, (3) determine which type of enrollment format in the Career and Workforce Development program has higher transfer of training, (4) evaluate if CSE can predict different rates of learning, (5) determine if CSE correlates positively with affective and utility measures of reaction surveys, and (6) further examine the finding that utility measures positively correlate with knowledge gains. In order to do this, eight Western Kentucky University Career and Workforce Development training courses were evaluated. The study did not find support for any of the hypotheses. Possible reasons for this lack of support include a small sample size, a lack of responses to the transfer survey, the number of different courses evaluated, and characteristics of the training courses such as different trainers. Thus, additional research is needed in this area to better understand the nature of the relationships between CSE, perceptions of transfer, utility reactions, affective reactions, and training course knowledge gains.
15

Påverkan och störningar : En kvalitativ studie om yttre påverkan på trafikledare i störda lägen på DLC Hallsberg / Disturbances and affecting factors : A qualitative study on the affect of external events on train dispatchers in disrupted situations in DLC Hallsberg

Nilsson, Lisa January 2012 (has links)
Trafikledare arbetar dygnet runt, året runt för att planera tågtrafiken i Sverige.  De ser till att tågen förs fram säkert på ett riskfritt sätt men även att det är säkert för de som arbetar längs spåren (Roth m.fl., 1999; Trafikledare, 2012). Det är ett komplext arbete med höga krav på trafikledarna. Denna studie undersöker vilka yttre intressenter och faktorer som påverkar trafikledarna, på driftledningscentralen i Hallsberg, främst i störda lägen. Studien har sin grund i teoriramverket resilience, där man undersöker hur operatörer arbetar under normala förhållanden i säkerhetskritiska system. Genom observationer och intervjuer på driftledningscentralen i Hallsberg under våren 2012 har trafikledare studerats för att förklara vad det finns för yttre intressenter och faktorer, vad störda lägen är och hur dessa hanteras. Slutsatserna studien drar är att yttre intressenter och faktorer som påverkar trafikledarnas i deras arbete är allt och alla som är inblandade i järnvägen, från passagerare till tågförare till olika väderförhållanden. Ett stört läge är en händelse som beroende på tid och plats, kan bli mer eller mindre stor, och påverka mer eller mindre mycket. Trafikledarna har en stor repertoar av handlingar att agera efter vid störningar och att de uppvisar resilienta förmågor.
16

Molecular gas around the binary star R Aquarii

Olander, Terese January 2017 (has links)
At the end of the lives of low- to intermediate mass stars they can be found on the asymptotic giant branch (AGB). The AGB phase ends when the entire circumstellar envelope (CSE) is blown away in a superwindphase, in the end creating a planetary nebula. It is unknown what shapes the CSE and the planetary nebula. Binarity is a favored theory. In order to test this theory the CSE around the star R Aquarii has been studied using the emission from different molecules observed with ALMA. R Aquarii is a nearby binary system and therefore easy to study. The system consists of a Mira variable on the AGB and a hot white dwarf. It was found that only in the emission from the 12CO J=3–2 transition were the CSE resolved enough for any structure to be seen. The morphology was irregular and no clear symmetry was seen. A spot in the same molecular line was detected at high velocities (v = -23 km/s) relative to the star at a projected distance of 7 arcsec south of R Aqr. Line profiles for 12CO and 13CO follow the same shape but differs in magnitude, indicating that they can be found in the same structure. A mass loss rate of 6.5·10-7 solar masses per year was calculated for R Aquarii using line intensities obtained from the line profile of 12CO. The morphology and kinematics of the CO CSE of R Aquarii are discussed within the limitations of the current data set. More observations with better resolution are needed to better understand the morphology of the CSE of R Aquarii and draw firm conclusions.
17

Planning Support for Running Large Scale Exercises as Learning Laboratories

Voshell, Martin G. 26 June 2009 (has links)
No description available.
18

Efeitos diferenciais do sulfeto de hidrogênio exógeno e endógeno na sinovite experimental induzida por carragenina em ratos Wistar. / Differential effects of hydrogen sulphide exogenous and endogenous in experimental synovitis induced by carrageenan in Wistar rats.

Valentim, Eduardo Ekundi 09 December 2010 (has links)
Este estudo se propôs a avaliar o efeito do gás sulfídrico (H2S), produzido endogenamente em mamíferos, na sinovite induzida pela injeção intra-articular de carragenina (CGN) no joelho de ratos Wistar (250 g). Ratos foram tratados (-60 min) com indometacina, o inibidor da cistationina <font face=\"Symbol\">g-liase DL-propargilglicine (PGly) ou doador de H2S reagente de Lawesson ( LR).Os parâmetros funcionais e bioquímicos foram avaliados 4h após. Ratos com sinovite exibiram dor, alodinia e edema articular. Na cavidade articular foram mensurados níveis elevados de neutrófilos (> MPO), nitração de resíduos protéicos (3-NT), atividade da iNOS, NOx-, caspase-1, IL-1<font face=\"Symbol\">&#946 e via NF-<font face=\"Symbol\">kB. O LR ou indometacina, mas não PGly, reduziu significativamente a nocicepção, edema e marcadores inflamatórios, exceto iNOS, NOx-, 3-NT e NF-<font face=\"Symbol\">kB. A PGly não modificou a dor e inflamação, mas aumentou o numero de macrófagos e atividade da iNOS (NOx-) e AP-1. Conclui-se que, enquanto a administração exógena do LR produz efeitos antiinflamatórios e anti-nociceptivos, o H2S endógeno exerce pouco efeito anti-sinovite. / In this study we evaluated the effects of exogenous and endogenous H2S on Wistar rat knee synovitis induced by the intra-articular injection of carrageenan (CGN). One hour prior to CGN injection, Rats were pre-treated with indomethacin, an inhibitor of H2S formation (DL-propargylglycine) or an H2S donor Lawessons reagent (LR). CGN evoked knee inflammation, as characterized by impaired gait, secondary allodynia of the hindpaw, joint swelling, neutrophil infiltration, increased MPO, 3-NT residues, inducible NOS (iNOS) activity and NOx-, caspase-1 and NF-<font face=\"Symbol\">kB activation. Pretreatment with LR or indomethacin significantly attenuated the pain and all the inflammatory / biochemical changes, except for the increased iNOS activity, NOx- and 3-NT. PGly potentiated synovial iNOS activity (and NOx-), enhanced macrophage infiltration and AP-1 activation, but had no effect on oedema and pain. Whereas exogenous H2S delivered to the knee joint can produce a significant anti-inflammatory and anti-nociceptive effect, locally produced H2S exerts little immunomodulatory effect.
19

Redução da produção de H2S no fígado de camundongos alimentados com dieta hiperlipídica. / Reduction in H2S production in the livers of mice fed a hyperlipidic diet.

Barbosa, Bruna Leoncio 28 May 2019 (has links)
H2S é um gasotransmissor com atua regulando processos fisiológicos e fisiopatológicos. É sintetizado principalmente pelas enzimas cistationinagama-liase (CSE) e cistationina beta-sintase (CBS), ambas dependentes do co-fator 5-fosfato de pirodoxal, e que utilizam o L-cisteína como substrato. Essas enzimas estão presentes no fígado. O camundongo knockout para CBS (CBS KO) apresenta fenótipo de homocistinúria, ou seja, além da homocisteinemia apresenta estresse oxidativo, fibrose e esteatose hepática. Ademais, há estudos in vitro sugerindo um papel desse gás reduzindo a captação de glicose hepática. A hipótese desse projeto é que haja redução precoce da produção de H2S pelo fígado de camundongos alimentados com dieta hiperlipídica (DHL) e esse seja um evento anterior à instalação do fígado gorduroso ou DGHNA associada à obesidade induzida pela DHL, DIO. Para isso, avaliamos a evolução ponderal, consumo alimentar e calórico diários, a tolerância a glicose e a insulina (GTT, ITT e Kitt), a morfohistologia hepática com corantes HE e picrocirius red, expressão proteica e gênica das enzimas CBS e CSE, a quantificação do conteúdo de triglicérides, a deteção de F4/80 e a atividade de enzimas antioxidantes (catalase, GPx e arginase) em amostras de fígado de camundongos machos C57Bl6 alimentados com a DHL por 5 períodos distintos (10, 20, 40, 60 e 80 dias de dieta). Detectamos aumento da massa corporal final a partir de 20 dias de DHL. O consumo alimentar diário foi menor nos animais com a DHL, porém com maior consumo calório do que os respectivos controles. A glicemia basal foi maior nos animais com DHL desde os 10 dias, com exceção o grupo com 40 dias. Houve maior intolerância à glicose desde 10 dias de DHL seguida de resistência à insulina a partir de 20 dias de DHL. Foi detectada presença de vacúolos intracelular nos hepatócitos a partir de 20 dias de DHL, no entanto, a presença de hepatócitos comprometidos foi de aproximadamente 2% aos 20 dias da DHL, cerca de 5% aos 40 dias da DHL e aproximadamente 60% com 60 e 80 dias da DHL. Aos 80 dias de DHL foi detectada balonização de hepatócitos, presença de infiltrado inflamatório identificado pelo aumento da marcação com F4/80, maior detecção de fibras colágenas nos espaços vasculares e aumento da atividade da enzima sérica AST. Houve redução para aproximadamente 50% da produção do H2S nas amostras de fígado dos animais a partir de 40 dias da DHL, porém sem relação clara com as modificações detectadas na expressão das enzimas CBS e CSE. Diante desses dados, concluímos que a DHL leva à intolerância à glicose, seguida de aumento da massa corporal e resistência ao efeito hipoglicemiante da insulina e que o desenvolvimento de fígado gorduroso é um evento mais tardio. Vimos que o espectro da DGHNA desenvolvida apresenta características de esteato-hepatite incipiente, com balonização dos hepatócitos, infiltrado inflamatório presente, discreto aumento de deposição de fibras colágenas e aumento da enzima hepática circulante AST. A redução da produção do gás apareceu após a instalação da resistência à insulina, mas anterior ao estabelecimento da DGHNA. Portanto, concluímos que a alteração na produção hepática do H2S pode ser um evento precoce associado ao desenvolvimento da DGHNA e que merece ser investigado seu potencial papel na progressão de estatose a EHNA com fibrose e cirrose. No entanto, será importante buscar um outro modelo animal para estudo dessa evolução. / Hydrogen sulfide (H2S) is a gaseous signaling molecule that regulates a variety of physiological and pathophysiological processes. It is primarily synthesized by cystathionine-gamma-lyase (CSE) and cystathionine beta-synthase (CBS), which are expressed in the liver, require 5\'-pyrodoxal phosphate as a co-factor, and use L-cysteine as a substrate. Interestingly, CBS knockout (CBS KO) mice present homocystinuria and associated homocysteinemia, as well as oxidative stress, fibrosis and hepatic steatosis. Furthermore, in vitro studies suggest that this gas reduces hepatic glucose uptake. It was hypothesized that mice fed a high fat diet (HFD) would display an early reduction H2S production by the liver and that this event would occur prior to the establishment of fatty liver or NAFLD, which is associated with diet induced obesity (DIO). Towards the goal of gaining a better understanding of H2S production during the onset and progression of DIO, male C57B16 mice were fed a HFD for 10, 20, 40, 60 or 80 days. During the experimental period, weight evolution, daily food and caloric intake, as well as glucose and insulin tolerance (GTT, ITT and Kitt) were evalauted. At the end of each time period hepatocyte morphology was assessed by HE and picrocirius red staining, CBS and CSE gene and protein expression were evaluated, triglyceride content was quantified, F4/80 antigen was detected and antioxidant enzyme (catalase, GPx and arginase) activites were determined. The results showed that mice fed a HFD for 20 days or longer presented an increase in final body weight. All of the HFD groups presented reduced daily food intake, but higher caloric intake, when compared to their respective controls. All of the animals fed a HFD had increased basal glycemia levels, with the exception of the group fed the diet for 40 days. Reduced glucose tolerance and insulin resistance were observed after consuming the HFD for 10 and 20 days, respectively. Intracellular vacuoles were detected in the hepatocytes after 20 days of the HFD. The amount of compromised hepatocytes increased from 2% after 20 days of the HFD, to about 5% after 40 days, to approximately 60% after 60 and 80 days. After consuming the HFD for 80 days, there was an observed ballooning of hepatocytes, increased F4/80 detection indicating the presence of inflammatory infiltrates, increased collagen fiber detection in the vascular spaces, and increased serum AST activity. There was a ~50% reduction in H2S production in the liver samples from animals fed a HFD for 40 days; however, there was no clear relationship with the alterations detected in CBS and CSE gene or protein expression. Based on the results, it was concluded that an HFD promotes glucose intolerance, followed by increased body mass and insulin resistance and that the development of fatty liver occurs later. Additionally, the spectrum of the developed NAFLD presented incipient steatohepatitis characteristics, such as: hepatocyte ballooning, inflammatory infiltrate, a slight increase in collagen fiber deposition, and an increase in circulating liver AST levels. The reduction in H2S gas production appeared after the installation of insulin resistance, but prior to the establishment of NAFLD. Therefore, we conclude that alterations in hepatic H2S production may be an early event associated with the onset of NAFLD and that its potential role in the progression of steatosis and NASH with fibrosis and cirrhosis deserves to be investigated. However, it will be important to evaluate this evolution in other animal models.
20

Efeitos diferenciais do sulfeto de hidrogênio exógeno e endógeno na sinovite experimental induzida por carragenina em ratos Wistar. / Differential effects of hydrogen sulphide exogenous and endogenous in experimental synovitis induced by carrageenan in Wistar rats.

Eduardo Ekundi Valentim 09 December 2010 (has links)
Este estudo se propôs a avaliar o efeito do gás sulfídrico (H2S), produzido endogenamente em mamíferos, na sinovite induzida pela injeção intra-articular de carragenina (CGN) no joelho de ratos Wistar (250 g). Ratos foram tratados (-60 min) com indometacina, o inibidor da cistationina <font face=\"Symbol\">g-liase DL-propargilglicine (PGly) ou doador de H2S reagente de Lawesson ( LR).Os parâmetros funcionais e bioquímicos foram avaliados 4h após. Ratos com sinovite exibiram dor, alodinia e edema articular. Na cavidade articular foram mensurados níveis elevados de neutrófilos (> MPO), nitração de resíduos protéicos (3-NT), atividade da iNOS, NOx-, caspase-1, IL-1<font face=\"Symbol\">&#946 e via NF-<font face=\"Symbol\">kB. O LR ou indometacina, mas não PGly, reduziu significativamente a nocicepção, edema e marcadores inflamatórios, exceto iNOS, NOx-, 3-NT e NF-<font face=\"Symbol\">kB. A PGly não modificou a dor e inflamação, mas aumentou o numero de macrófagos e atividade da iNOS (NOx-) e AP-1. Conclui-se que, enquanto a administração exógena do LR produz efeitos antiinflamatórios e anti-nociceptivos, o H2S endógeno exerce pouco efeito anti-sinovite. / In this study we evaluated the effects of exogenous and endogenous H2S on Wistar rat knee synovitis induced by the intra-articular injection of carrageenan (CGN). One hour prior to CGN injection, Rats were pre-treated with indomethacin, an inhibitor of H2S formation (DL-propargylglycine) or an H2S donor Lawessons reagent (LR). CGN evoked knee inflammation, as characterized by impaired gait, secondary allodynia of the hindpaw, joint swelling, neutrophil infiltration, increased MPO, 3-NT residues, inducible NOS (iNOS) activity and NOx-, caspase-1 and NF-<font face=\"Symbol\">kB activation. Pretreatment with LR or indomethacin significantly attenuated the pain and all the inflammatory / biochemical changes, except for the increased iNOS activity, NOx- and 3-NT. PGly potentiated synovial iNOS activity (and NOx-), enhanced macrophage infiltration and AP-1 activation, but had no effect on oedema and pain. Whereas exogenous H2S delivered to the knee joint can produce a significant anti-inflammatory and anti-nociceptive effect, locally produced H2S exerts little immunomodulatory effect.

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