• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 45
  • 24
  • 11
  • 9
  • 4
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 115
  • 41
  • 20
  • 13
  • 12
  • 10
  • 10
  • 9
  • 9
  • 9
  • 8
  • 7
  • 7
  • 6
  • 6
  • 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.
91

Avaliação do potencial leishmanicida de fármacos que atuam na rota bioquímica de esteróis / Evaluation of the Leishmanicidal Potential from Drugs which Act in the Sterols Biochemical Pathway

Yamamoto, Eduardo Seiji 26 April 2019 (has links)
A leishmaniose é uma doença negligenciada causada por protozoários parasitos do gênero Leishmania sp. e transmitida por vetores. Esta doença pode apresentar formas clínicas que variam de lesões cutâneas simples que podem desaparecer espontaneamente até a forma visceral, a qual acomete órgãos como baço, fígado, medula óssea e linfonodos, e pode levar a morte se não tratada corretamente. Além disso, de acordo com a Organização Mundial da Saúde as leishmanioses são endêmicas em 98 países. O tratamento ainda é feita principalmente com dois medicamentos, os antimoniais pentavalentes e anfotericina B, os quais causam uma série de efeitos secundários, além disso, relatos de resistência a esses fármacos têm sido publicados. Além disso, medicamentos alternativos aprovados para uso, como a miltefosina e pentamidina, também possuem sérios efeitos colaterais e nem sempre são efetivos para todas as espécies do parasito e/ou formas clínicas. Estes fatos demonstram que é necessário o desenvolvimento de fármacos alternativos para a quimioterapia das leishmanioses. Nesse sentido, o reposicionamento de fármacos se mostra como uma importante estratégia para o desenvolvimento de novas alternativas terapêuticas para a leishmaniose, pois fármacos já liberados para o uso em humanos podem ser reutilizados, diminuindo o tempo de desenvolvimento e custos empregados para o desenvolvimento de novos fármacos. Leishmania sp. possui como um dos principais lipídios o ergosterol, cuja rota metabólica é complexa e envolve uma série de enzimas, as quais, se corretamente bloqueadas poderão suprimir a produção do ergosterol e, portanto, a viabilidade de parasitos. Considerando estes aspectos, o presente estudo objetivou investigar a ação leishmanicida de fármacos que possuem ação inibitória em enzimas da via de esteróis como o fármaco anti-hiperlipidêmico rosuvastatina (inibidor da enzima 3-hidroxi-3-metil-glutaril-CoA redutase) e, os antifúngicos voriconazol, tiaconazol, fenticonazol (inibidores da enzima 14 alfa-metilesterol 14-demetilase), naftifina e tolnaftato (inibidores da enzima esqualeno epoxidase), e por fim a nistatina que age diretamente sobre ergosterol. O potencial contra formas promastigotas e amastigotas intracelulares de L. (L.) amazonensis, L. (L.) infantum e L. (V.) braziliensis foram avaliados, e então foram investigadas possíveis alterações ultraestruturais, fisiológicas em promastigotas de L. (L.) amazonensis (formação de poros de membrana, e alteração do potencial de membrana mitocondrial) ou nas células hospedeiras (produção de óxido nítrico, peróxido de hidrogênio, e mudanças no pH intracelular). O fenticonazol, tioconazol, nistatina e o tolnaftato foram capazes de eliminar as formas promastigotas e amastigotas intracelulares, sendo a nistatina, o tolnaftato e o fenticonazol os mais seletivos para amastigotas das três espécies de parasitos estudados. Por outro lado, rosuvastatina, voriconazol e a naftifina não apresentaram ação contra formas amastigotas intracelulares. Além disso, os fármacos com atividade leishmanicida alteraram morfologicamente e fisiologicamente a mitocôndria do parasito. Apesar de não haver estímulo da produção de H2O2 ou NO por parte dos fármacos analisados, o fenticonazol foi capaz de alcalinizar macrófagos hospedeiros infectados. Considerando que estes fármacos foram capazes de inibir o crescimento de multi-espécies do parasito no interior dos macrófagos, esses resultados sugerem que medicamentos antifúngicos podem ser interessantes alvos para reposicionamento da quimioterapia das leishmanioses tegumentar e visceral / Leishmaniosis is a neglected disease caused by parasitic protozoa belonging to the genus Leishmania sp. and transmitted by vectors. This disease presents different clinical forms ranging from single lesion, that can heal spontaneously, to the visceral form, that affects the spleen, liver, bone marrow and lymph nodes, and may lead to death if not properly treated. Additionally, according to the World Health Organization, leishmaniosis is endemic to 98 countries. The treatment is still carried out with two main drugs, antimonials and amphotericin B that induce side effects; in addition, reports about the emergence of parasite resistance have been published. Besides, alternative drugs such as miltefosine and pentamidine still have serious side effects and are not always effective to treat all Leishmania species and/or clinical form. In this regard, drug repurposing has been considered an important strategy to develop new therapeutic alternatives to leishmaniasis chemotherapy, since drugs already approved to human use may be reused, decreasing time and costs needed for the research of new drugs. Leishmania sp. possesses ergosterol as the main membrane lipid, and the metabolic pathway to produce this lipid is complex and involves different enzymes, which if correctly inhibited may suppress ergosterol production and, therefore, parasite viability. Considering these aspects, the aims of this study is to investigate the leishmanicidal potential of drugs who inhibit enzymes of the ergosterol pathway, such as the anti-hyperlipidemic drug rosuvastatin (inhibitor of the 3-hydroxy-3-methyl-glutaryl-CoA reductase), the antifungals voriconazole, tioconazole, fenticonazole, (inhibitors of the 14 Alpha-methylsterol 14-demethylase), naftifine and tolnaftate (inhibitors of squalene epoxidase), and nystatin, that acts directly on ergosterol. The anti-promastigote and anti-amastigote potentials of drugs against L. (L.) amazonensis, L. (L.) infantum and L. (V.) braziliensis were evaluated; ultrastructural and physiological alterations of L. (L.) amazonensis promastigotes (membrane pore formation and mitochondrion membrane potential alterations) and host macrophages (nitric oxide and hydrogen peroxide productions and changes to intracellular pH) were investigated. Fenticonazole, tioconazole, nystatin and tolnaftate were capable to eliminate promastigote and amastigotes, being the most selective drugs nystatin, tolnaftate and fenticonazole to all studied species amastigotes. Rosuvastatin, voriconazole and naftifine were unable to eliminate amastigote forms. Furthermore, the drugs that possess leishmanicidal effects affected parasite mitochondrion. Although these drugs did not trigger the production of H2O2 or NO, fenticonazole was able to alkalinize host infected macrophages. Considering these drugs were able to inhibit multiple species of the parasite growth in macrophages, these results suggest that antifungal drugs can be interesting targets to be repurposed in the cutaneous and visceral leishmaniasis
92

Avaliação da fidelidade da referência externa em tecidos moles na cirurgia ortognática da maxila / Evaluation of the accuracy of soft tissue nasion reference point in maxillary surgery

Ramiro Beato Souza 26 March 2009 (has links)
Esse trabalho teve o objetivo de analisar a fidelidade da referência externa em tecidos moles no auxílio do posicionamento vertical da maxila. Foram selecionados 40 pacientes portadores de deformidade dentofacial e submetidos à osteotomia total da maxila. Os indivíduos foram divididos em 2 grupos no intuíto de avaliar duas técnicas de referência externa: a utilização da sutura em tecidos moles e o uso do fio de Kirschner. Esta última foi utilizada como a técnica do grupo-controle. Os dados foram colhidos em duas fases. Na primeira delas, foi realizada a mensuração da posição vertical da maxila antes da osteotomia Le Fort I e após a fixação da maxila, utilizando a referência externa. A partir desses números, foi obtida a alteração vertical de cada caso, colhida durante a cirurgia. Na segunda fase da coleta de dados, foram realizadas mensurações verticais da maxila baseadas nas radiografias cefalométricas pré e pós-operatórias. Assim, foi obtido o valor da alteração vertical de cada caso, baseado na documentação radiográfica. Após esta etapa, foi calculada a diferença entre a alteração vertical obtida durante a cirurgia e a alteração vertical colhida a partir das radiografias. Dessa forma, foram obtidos valores que correspondem às imperfeições no posicionamento vertical da maxila de cada paciente, tendo como base a posição do incisivo central superior. Os resultados foram comparados e analisados estatisticamente. A média aritmética da precisão no posicionamento vertical da maxila no grupo-controle foi de 0,52mm e do grupo da referência em tecidos moles foi de 0,65mm. A aplicação do teste t de Student a 5% revelou que não houve diferença estatística significativa entre o grau de precisão das duas técnicas de referência externa (P=0,429). Como conclusão, observou-se que as duas técnicas foram eficazes no auxílio ao posicionamento vertical da maxila e que a referência externa em tecidos moles apresentou um grau de precisão semelhante ao valor obtido com a técnica do fio de Kirschner. / The aim of this study was to analyze the accuracy of external reference placed in soft tissue nasion for vertical maxillary repositioning. Forty patients with dentofacial deformities who were to undergo Le Fort I maxillary osteotomy were separated into two groups to evaluate two different external reference measurement techniques: soft tissue nasion (study group) and Kirschner pins (control group). Data were collected in two phases. Initially the vertical position of the maxilla was assessed during surgery before Le Fort I osteotomy and after maxillary fixation, in relation to the external reference point, evaluating the intra-operative vertical alteration of each case. In the second phase, maxillary vertical measurements were done using the pre and pos-operative cephalometric radiographs to assess their radiographic vertical alteration. Differences among radiographic and intra-operative vertical variations of the maxilla were calculated to acquire values corresponding to discrepancies in maxillary positioning in relation to upper central incisor. Results were statistically compared and analyzed. The average of accuracy of vertical maxillary positioning was 0.525 mm for the control group and 0.650 mm for the study group. Student t test indicated no significant difference between both methods (P=0.429). In conclusion it was noted that both techniques were efficient for vertical maxillary repositioning and soft tissue nasion method showed a similar accuracy of that obtained with Kirschner pins.
93

Repositionnement des poissons migrateurs amphihalins européens dans un contexte de changement climatique : une approche exploratoire par modélisation dynamique mécaniste / Repositioning of European diadromous fish in a context of climate change : an exploratory study using a dynamic mechanistic modelling approach

Rougier, Thibaud 29 April 2014 (has links)
Le changement climatique en cours modifie les conditions environnementales et les espèces doivent s'adapter à ces nouvelles conditions, en restant sur place ou en se déplaçant conduisant alors à de nouvelles distributions. Ce repositionnement revêt deux dimensions principales : (i) l'adaptabilité des espèces aux nouvelles conditions (changement de traits d'histoire de vie) liée à la résilience des populations et (ii) leur capacité à explorer de nouveaux habitats favorables. Cette étude avait pour objectif l’élaboration d’un modèle dynamique mécaniste intégrant ces deux dimensions de manière à pouvoir évaluer, comprendre et prédire les possibilités de repositionnement des poissons migrateurs amphihalins européens face au changement climatique.Pour accomplir leurs cycles de vie, les espèces migratrices amphihalines utilisent nécessairement des écosystèmes dulçaquicoles, estuariens et marins. Ces cycles de vie particuliers leur confèrent un plus grand potentiel de repositionnement que les espèces dulçaquicoles. Une base de données sur les traits de vie de ces espèces intégrant notamment ceux pouvant potentiellement être influencés par le changement climatique et ceux pouvant jouer un rôle dans le potentiel de dispersion des espèces a été construite pour l’ensemble des espèces amphihalines européens. Une méthode d’analyse multicritère hiérarchique a été proposée pour définir un indice basé sur les traits de vies visant à caractériser le potentiel de repositionnement des espèces migratrices amphihalines.Le modèle GR3D (Global Repositioning Dynamics for Diadromous fish Distribution) a ensuite été développé pour étudier de façon dynamique le repositionnement potentiel de ces espèces, à large échelle, dans un contexte scénarisé de changement climatique. Il s’agit d’un modèle de simulation stochastique, individus centré, intégrant les principaux processus de dynamique de population d’un poisson migrateur amphihalin (reproduction, mortalité, croissance, migration de montaison avec dispersion, migration de dévalaison).Un premier cas d’étude exploratoire simulant le repositionnement d’une population virtuelle de grande alose (Alosa alosa) de son bassin versant d’origine à un bassin versant voisin inhabité dans un contexte d’augmentation de la température a permis de réaliser une analyse de sensibilité globale du modèle GR3D à la fois aux paramètres incertains de dynamique de population et aux paramètres reliés à la structure de l’environnement. Il a été mis en évidence une sensibilité particulière du modèle aux paramètres liés à la durée de vie et à la mortalité en mer ainsi qu’à la distance entre les deux bassins versants de l’environnement pour déterminer le succès de colonisation.Enfin, l’utilisation du modèle GR3D sur un cas d’application réel a permis de commencer à évaluer l’évolution de la persistance de la grande alose à l’échelle de son aire de répartition (i.e. la façade atlantique) dans un contexte de changement climatique.Les simulations du modèle GR3D devraient ainsi trouver à terme des applications pour la gestion et la conservation des espèces migratrices amphihalines. / The ongoing climate change is modifying the environmental conditions and species have to adapt to these new constraints, either on the same site or migrating in new suitable sites leading to a modification of distribution area. This repositioning has two main dimensions: (i) the species capacity to adapt to the new conditions (modification of life history traits) which is linked to the species resilience and (ii) the species capacity to explore new suitable habitats. The objective of this study was to build a mechanistic model incorporating these two dimensions in order to evaluate, understand and predict the repositioning possibilities of European diadromous fish facing climate change.In their life cycles, diadromous fish species have to use freshwater, estuarine and marine ecosystems. These specific life history strategies represent a great repositioning potential in comparison to freshwater fish species. A database of diadromous fish life history traits, incorporating those that could be influenced by climate change and those that could have an importance in the species repositioning potential, has been built. An Analytic Hierarchy Process has been suggested to develop a composite score based on life traits aiming at assessing the diadromous species repositioning potential.Then, the GR3D model (Global Repositioning Dynamics for Diadromous fish Distribution) has been developed in order to study with a dynamic approach the repositioning potential of diadromous fish, at a large scale, in a context of climate change. This model is a simulation, stochastic and individual-based model incorporating the main population dynamics processes of a diadromous fish (reproduction, mortality, growth, upstream migration with dispersal and downstream migration).A first exploratory application case simulating the repositioning of a virtual allis shad (Alosa alosa) population between two river catchments under a scenario of temperature increase has been carried out and the associated global sensitivity analysis has been performed in order to determine the influence of uncertain population dynamics parameters and of parameters defining the landscape stucture. The results showed that dispersal distance and parameters related to sea lifespan and to survival at sea were crucial to determine the success of colonization.Finally, the use of GR3D in a real application case allowed improving the understanding of allis shad persistence at the scale of its distribution area (i.e. the Atlantic coast) in a context of climate change.Over time, simulation results of GR3D should be relevant and useful in management and conservation of diadromous fish species.
94

Parents' stories of homework : experiences alongside their children and families

Murray, Tamara 12 January 2009
The objective of this program of research was to listen to parents voices on homework with a focus on what homework means for their children, themselves and their families. While, within this body of literature, there is consensus on a definition of homework, a multitude of studies on homework and its effect on academic achievement and the development of work habits, and an extensive body of literature on types of homework assignments, there are no known qualitative studies on homework from parents perspectives. Within schools, teachers are positioned as knowing professionals and parents are positioned as helpers, who know less about the learning process. Power and authority rest with educators who make decisions important to teaching and learning decisions about homework policies and practices, for example often with little or no parent input or participation. Because teachers ask for little input from parents, parents rarely feel they can talk to teachers about their childrens experiences with homework and the resulting impact on their family.<p> Determining what knowledge parents of elementary school children (pre-Kindergarten through Grade 8) hold about homework, how they feel about homework, how homework impacts their children, how homework impacts them as parents, and how homework impacts their families was the focus of this narrative inquiry. The parents stories highlight the non-academic benefits the parents believe exist for their children through their engagement with homework. They also bring to the fore the many reasons homework can be problematic for their children and for them as they attend to the individuality of their children and the complexity of their family lives. They raise important issues for educators to consider in relation to homework: the implications variations within families, schools, teachers, parents and students may have for homework policies and practices; the need for reciprocity in home/school communications and the development of equitable rather than hierarchical relationships between parents and educators. Possibilities for changes in teacher education, both preservice and inservice; for a rethinking of policy and practice for both parents and educators; and for the direction of future research all emerge in this work.
95

Parents' stories of homework : experiences alongside their children and families

Murray, Tamara 12 January 2009 (has links)
The objective of this program of research was to listen to parents voices on homework with a focus on what homework means for their children, themselves and their families. While, within this body of literature, there is consensus on a definition of homework, a multitude of studies on homework and its effect on academic achievement and the development of work habits, and an extensive body of literature on types of homework assignments, there are no known qualitative studies on homework from parents perspectives. Within schools, teachers are positioned as knowing professionals and parents are positioned as helpers, who know less about the learning process. Power and authority rest with educators who make decisions important to teaching and learning decisions about homework policies and practices, for example often with little or no parent input or participation. Because teachers ask for little input from parents, parents rarely feel they can talk to teachers about their childrens experiences with homework and the resulting impact on their family.<p> Determining what knowledge parents of elementary school children (pre-Kindergarten through Grade 8) hold about homework, how they feel about homework, how homework impacts their children, how homework impacts them as parents, and how homework impacts their families was the focus of this narrative inquiry. The parents stories highlight the non-academic benefits the parents believe exist for their children through their engagement with homework. They also bring to the fore the many reasons homework can be problematic for their children and for them as they attend to the individuality of their children and the complexity of their family lives. They raise important issues for educators to consider in relation to homework: the implications variations within families, schools, teachers, parents and students may have for homework policies and practices; the need for reciprocity in home/school communications and the development of equitable rather than hierarchical relationships between parents and educators. Possibilities for changes in teacher education, both preservice and inservice; for a rethinking of policy and practice for both parents and educators; and for the direction of future research all emerge in this work.
96

Ompositioneringens dolda hot : Riskerna med varumärkesompositioneringar

Tayeh, Ruaa, Uhman, Jennifer January 2011 (has links)
The purpose with this essay is to study how companies use the repositioning process and identify the risks involved from a business perspective. We have chosen to base our essay on the following research questions: What reasons are there for a company to initiate a repositioning?, What does it mean for companies to implement a repositioning?, What are the risks with a repositioning? We have used a qualitative research method and have chosen to interview six respondents which in various ways are actively working with brand repositioning. Our study has been implemented with and deductive character. The most important conclusion that we observed after implementing our study is that repositioning is a high-risk project. Instead of changing their entire brand image, companies should instead make small changes and revitalize the brand by developing the strength that already exist. The biggest risks that we have identified is that a repositioning may result in that the company loses their customers, customer loyalty but also losing market shares. We consider that a repositioning only should be implemented if it is absolutely necessary and when the risks are imminent. / SyfteSyftet med uppsatsen är att studera hur företagen använder sig av ompositioneringsprocesser samt identifiera de risker det innebär ur ett företagsperspektiv. Vi har valt att arbeta med följande forskningsfrågor: Vilka anledningar finns det till att ett företag genomför en ompositionering?, Vad innebär det för företagen att genomföra en ompositionering?, Vilka risker medför en ompositionering? Vi har använt oss av en kvalitativ forskningsmetod och valt att intervjua sex respondenter som på olika sätt aktivt arbetar med varumärkesompositionering. Vår studie har kommit att genomföras med en deduktiv karaktär. SlutsatserEfter att ha genomfört vår studie har vi kunnat konstatera att en ompositionering är ett högriskprojekt. Istället för att förändra sin hela varumärkesimage bör företagen istället genomföra små förändringar och vitalisera varumärket genom att utveckla de styrkor som redan finns. De största riskerna som vi har identifierat är att en ompositionering kan leda till att företaget förlorar sina lojala kunder och tappar marknadsandelar. Vi anser att en ompositionering enbart ska genomföras om det är absolut nödvändigt då riskerna är överhängande.
97

Radiologische Querschnittsstudie zur Qualitätsverbesserung von Panoramaschichtaufnahmen mittels Zungenrepositionsmanöver

Sömmer, Christian 16 April 2009 (has links)
No description available.
98

Avaliação da fidelidade da referência externa em tecidos moles na cirurgia ortognática da maxila / Evaluation of the accuracy of soft tissue nasion reference point in maxillary surgery

Ramiro Beato Souza 26 March 2009 (has links)
Esse trabalho teve o objetivo de analisar a fidelidade da referência externa em tecidos moles no auxílio do posicionamento vertical da maxila. Foram selecionados 40 pacientes portadores de deformidade dentofacial e submetidos à osteotomia total da maxila. Os indivíduos foram divididos em 2 grupos no intuíto de avaliar duas técnicas de referência externa: a utilização da sutura em tecidos moles e o uso do fio de Kirschner. Esta última foi utilizada como a técnica do grupo-controle. Os dados foram colhidos em duas fases. Na primeira delas, foi realizada a mensuração da posição vertical da maxila antes da osteotomia Le Fort I e após a fixação da maxila, utilizando a referência externa. A partir desses números, foi obtida a alteração vertical de cada caso, colhida durante a cirurgia. Na segunda fase da coleta de dados, foram realizadas mensurações verticais da maxila baseadas nas radiografias cefalométricas pré e pós-operatórias. Assim, foi obtido o valor da alteração vertical de cada caso, baseado na documentação radiográfica. Após esta etapa, foi calculada a diferença entre a alteração vertical obtida durante a cirurgia e a alteração vertical colhida a partir das radiografias. Dessa forma, foram obtidos valores que correspondem às imperfeições no posicionamento vertical da maxila de cada paciente, tendo como base a posição do incisivo central superior. Os resultados foram comparados e analisados estatisticamente. A média aritmética da precisão no posicionamento vertical da maxila no grupo-controle foi de 0,52mm e do grupo da referência em tecidos moles foi de 0,65mm. A aplicação do teste t de Student a 5% revelou que não houve diferença estatística significativa entre o grau de precisão das duas técnicas de referência externa (P=0,429). Como conclusão, observou-se que as duas técnicas foram eficazes no auxílio ao posicionamento vertical da maxila e que a referência externa em tecidos moles apresentou um grau de precisão semelhante ao valor obtido com a técnica do fio de Kirschner. / The aim of this study was to analyze the accuracy of external reference placed in soft tissue nasion for vertical maxillary repositioning. Forty patients with dentofacial deformities who were to undergo Le Fort I maxillary osteotomy were separated into two groups to evaluate two different external reference measurement techniques: soft tissue nasion (study group) and Kirschner pins (control group). Data were collected in two phases. Initially the vertical position of the maxilla was assessed during surgery before Le Fort I osteotomy and after maxillary fixation, in relation to the external reference point, evaluating the intra-operative vertical alteration of each case. In the second phase, maxillary vertical measurements were done using the pre and pos-operative cephalometric radiographs to assess their radiographic vertical alteration. Differences among radiographic and intra-operative vertical variations of the maxilla were calculated to acquire values corresponding to discrepancies in maxillary positioning in relation to upper central incisor. Results were statistically compared and analyzed. The average of accuracy of vertical maxillary positioning was 0.525 mm for the control group and 0.650 mm for the study group. Student t test indicated no significant difference between both methods (P=0.429). In conclusion it was noted that both techniques were efficient for vertical maxillary repositioning and soft tissue nasion method showed a similar accuracy of that obtained with Kirschner pins.
99

Operationssjuksköterskans kunskaper om preventivt arbete mot trycksår och nervskador : En enkätstudie / Operating theatre nurse's knowledge of preventive work against pressure ulcers and nerve damage : A survey

Helmersson, Emelie, Mattisson, Amanda January 2018 (has links)
Bakgrund: I Sverige rapporteras det årligen om patienter som drabbats av postoperativa trycksår och nervskador, till följd av felaktig positionering och/eller utesluten repositionering. Dessa komplikationer orsakar patienten onödigt lidande och förlängda vårdtider samt orsakar höga kostnader för sjukvården. Trots tidigare forskning som redogör för hur dessa komplikationer kan förebyggas saknas det ännu forskning om hur operationssjuksköterskans kunskaper är inom ämnet. Därmed är studien utförd för att undersöka och beskriva operationssjuksköterskans kunskaper idag utifrån ett stickprov bestående av några slumpmässigt utvalda sjukhus i Sverige. Syfte: Syftet med studien är att belysa operationssjuksköterskans kunskaper om positionering och repositionering för att förebygga postoperativa komplikationer, specifikt trycksår och nervskador. Metod: Studien utfördes som en empirisk tvärsnittsstudie med deskriptiv design och kvantitativ ansats där data samlades in via en egenutformad webbenkät. I studien deltog sju sjukhus i Sverige, vilket totalt resulterade i 137 enskilda deltagare. Resultat: Resultatet visade att dagens operationssjuksköterskor är intresserade av att få mer kunskap om preventivt arbete mot trycksår och nervskador. Det visade även en varierad åsikt om vem som besitter huvudansvaret för repositioneringen under operation. Slutsats: Deltagarna informerade om att de inte får regelbunden information inom ämnet från sin arbetsplats. Detta kan vara en av anledningarna till att repositionering inte utförs i den bemärkelsen som är rekommenderat enligt tidigare forskning. Det bör beslutas om vem som ska besitta huvudansvaret eller om det skall införas fasta rutiner för att därmed bidra till att patienten inte utsätts för onödigt lidande. / Background: Yearly in Sweden, patients are reported suffering from postoperative pressure ulcer and nerve damage due to incorrect positioning and/or excluded repositioning. These complications cause patient unnecessary suffering and extended time in care in the hospitals as well causes high costs for healthcare. Despite previous research which describes how these complications can be prevented, there is limited research on how the operating theatre nurse´s knowledge is on the subject. The study is conducted to investigate and describe today´s operating theatre nurses knowledge based on a sample of some randomly selected hospitals in Sweden. Aim: The aim of the study is to highlight the operating theatre nurse´s knowledge of positioning and repositioning to prevent postoperative complications, specifically pressure ulcers and nerve damage. Method: The study was conducted as an empirical cross-sectional study with descriptive design and quantitative approach where data was collected by a self-designed web questionnaire. In the study, seven hospitals in Sweden were participating, which resulted in 137 participants. Results: The results showed that today's theatre nurses are interested in gaining more knowledge about preventive work against postoperative complications, specific pressure ulcers and nerve injuries. It also showed a varied perception about who has the main responsibility for repositioning during surgery. Conclusion: Participants informed that they don´t receive regular information within the subject from their workplace. This may be one of the reasons why repositioning is not performed as recommended by previous research. It should be decided who should be in charge of the repositioning to prevent patients from unnecessary suffering.
100

Optical Sensor Uncertainties and Variable Repositioning Times in the Single and Multi-Sensor Tasking Problem

Michael James Rose (9750503) 14 December 2020 (has links)
<div>As the number of Resident Space Objects around Earth continues to increase, the need for an optimal sensor tasking strategy, specifically with Ground-Based Optical sensors, continues to be of great importance. This thesis focuses on the single and multi-sensor tasking problem with realistic optical sensor modeling for the observation of objects in the Geosynchronous Earth Orbit regime. In this work, sensor tasking refers to assigning the specific?c observation times and viewing directions of a single or multi sensor framework to either survey for or track new or existing objects. For this work specifically, the sensor tasking problem will seek to maximize the total number of Geosynchronous Earth Orbiting objects to be observed from a catalog of existing objects with a single and multi optical sensor tasking framework. This research focuses on the physical assumptions and limitations on an optical sensor, and how these assumptions affect the single and multi sensor tasking scenario. First, the concept of the probability of detection of a resident space object is calculated based on the viewing geometry of the resident space object. Then, this probability of detection is compared to the system that avoids the computational process by implementing a classical heuristic minimum elevation constraint to an electro-optical charged coupled optical sensor. It is shown that in the single and multi-sensor tasking scenario if the probability of detection is not considered in the sensor tasking framework, then a rigid elevation constraint of around 25<sup>o</sup>-35<sup>o</sup> is recommended for tasking Geosynchronous objects. Secondly, the topic of complete geo-coverage within a single night is explored. A sensor network proposed by Ackermann et al. (2018) is studied with and without the probability of detection considerations, and with and without uncertainties in the resident space objects' states. (then what you have). For the multi-sensor system, it is shown that with the assumed covariance model for this work, the framework developed by Ackermann et al. (2018) does not meet the design requirements for the cataloged Geosynchronous objects from March 19th, 2019. Finally, the concept of a variable repositioning time for the slewing of the ground-based sensors is introduced and compared to a constant repositioning time model. A model for the variable repositioning time is derived from data retrieved from the Purdue Optical Ground Station. This model is applied to a single sensor scenario. Optimizers are developed using the two repositioning time functions derived in this work. It is shown that the constant repositioning models that are greater than the maximum repositioning time produce results close to the variable repositioning solution. When the optimizers are tested, it is shown that there is a small increase in performance only when the maximum repositioning time is significant.</div>

Page generated in 0.1307 seconds