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1
González, Antonio Pablo. « IDENTIFICACIÓN DE LOS GENES : Stx1, Stx2, eaeA Y hlyA, EN CEPAS DE Escherichia coli AISLADAS DE CANALES Y CARNE PROCESADA DE OVINOS ». Tesis de Licenciatura, Universidad Autónoma del Estado de México, 2018. http://hdl.handle.net/20.500.11799/94389.
Texte intégralRésumé :
E. coli productora de toxina shiga (ECST) y E. coli enterohemorrágica (ECEH) pertenecen a los grupos patógenos de Escherichia coli causantes de enfermedades diarreicas. La presencia de ECST y ECEH en estas enfermedades diarreicas se atribuye principalmente al consumo de vegetales y carnes provenientes de bovinos y ovinos contaminados con estos grupos patógenos y que actualmente se encuentran dentro de las etiologías más importantes del grupo de Enfermedades Trasmitidas por Alimentos (ETA). ECST y ECEH presentan los genes Stx1, Stx2, eaeA y hlyA que codifican a proteínas con cualidades toxicas para el hombre ocasionando graves enfermedades como la colitis hemorrágica (CH), síndrome urémico hemolítico (SUH) y purpura trombocitopénica trombótica (PTT). Por lo tanto, el objetivo de esta investigación es identificar la presencia de los genes Stx1, Stx2, eaeA y hlyA en los aislamientos de E. coli obtenidos de canales de ovinos en rastro municipal de Capulhuac y en carne procesada de ovinos provenientes de la ciudad de Toluca. Se analizaron 71 aislados de E. coli para la identificación genes característicos de los grupos patógenos de ECST y ECEH. Los resultados encontrados indican: los 18 aislamientos de E. coli obtenidas de la carne procesada de ovinos no se identifica la presencia los genes analizados y, por otro lado, de los 53 aislados obtenidos de las canales de ovinos en el rastro municipal de Capulhuac, México, amplificaron los genes Stx1 en 3.7% (2/53), Stx2 en 5.6% (3/53), eaeA en 3.7% (2/53) y hlyA en 3.7% (2/53). De tal manera, que estas canales puede ser una fuente potencial de infección por E. coli productora de toxina shiga y E. coli enterohemorrágica.
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MUNGO, DAVIDE PIETRO. « MEASUREMENT OF THE SM HIGGS BOSON PROPERTIES IN THE DIPHOTON DECAY CHANNEL WITH THE ATLAS RUN 2 DATASET ». Doctoral thesis, Università degli Studi di Milano, 2022. http://hdl.handle.net/2434/918268.
Texte intégralRésumé :
On the 4th July 2012, the ATLAS and CMS collaborations announced the discovery of a particle with mass around 125 GeV compatible with the Higgs boson predicted by the Standard Model. The long sought Higgs boson was observed combining the three most sensitive decay channels in a hadron collider, the H->yy, H->4l and H->WW channels. The collaborations have then started a huge effort in assessing its properties with the highest possible precision and found them to agree with the ones predicted for the SM Higgs boson within the statistical precision. Nowadays, this program is not settled yet: the Higgs boson still attracts our interest because it interacts with almost all the Standard Model particles and it is considered a portal towards new physics beyond the SM.
The work reported in this manuscript is fully part of this physic program, focusing on the measurement of the Higgs boson mass and production cross sections in the channel, performed with the pp collision dataset collected by ATLAS at LHC with a center-of-mass energy of 13 TeV and amounting to 139 fb^-1 . In this manuscript, the full analysis chain is described and particular emphasis is placed in the description of the innovative event categorization procedures I have designed for the coupling and mass measurements.
The Higgs boson production cross sections are measured in several different parametrizations in order to deeply explore its production phase space and represents the final Run 2 results for this decay channel. The results are up to a factor 4 more precise than latest results and they have been found to be compatible with the Standard Model prediction. The expected result for the Higgs mass measurement is reported as well and it presents a sizeable improvement with respect to the latest published results.
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Assumpção, Gustavo Lacerda Homem [UNESP]. « Avaliação dos padrões de susceptibilidade antimicrobianas e sorogrupos de cepas de Escherichia coli isoladas de bovinos leiteiros, portadoras e não portadoras dos genes stx1, stx2 e eae ». Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/94796.
Texte intégralRésumé :
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000738835.pdf: 2748761 bytes, checksum: dcad72914370b9d270982eb35f883ae3 (MD5)O presente estudo foi realizado no período de janeiro de 2012 a janeiro de 2013 em fazendas leiteiras da região de Dracena, São Paulo. Durante o período, foram coletadas 800 amostras de fezes com suabes retais em vacas leiteiras. Essas amostras foram levadas para o Laboratório de Microbiologia do Campus Experimental de Dracena, onde foram isoladas e identificadas 561 amostras para Escherichia coli. Após o isolamento foram extraídos os DNAs de todas as amostras pelo método da fervura e por PCR o DNA foi amplificado para se detectar a presença dos genes de virulência de E. coli pertencentes ao grupo STEC, produtora de toxina tipo shiga em 446 amostras. De todas as cepas isoladas 90 eram portadoras do gene stx1, 97 do gene stx2, 45 do gene eae, 37 dos genes stx1 e stx2, 110 dos genes stx1 e eae e 67 dos genes stx2 e eae. Foram isoladas também 115 cepas que não eram portadoras de nenhum dos genes de virulência de STECs do estudo. Todos os isolados de E. coli portadores de cada gene de virulência foram avaliados quanto a resistência frente a 10 antimicrobianos. Os percentuais de resistências aos antimicrobianos foram maiores para a lincomicina, penicilina e novobiocina e menores para ampicilina, neomicina e tetraciclina. Foram identificados os sorogrupos, dos quais os mais frequentes entre os isolados portadores do gene de virulência stx1 foram o O119 e O114; do gene de virulência stx2 foram os sorogrupos O9 e O8; e do gene de virulência eae foram os sorogrupos O9, O8 e O127. Todos os isolados de E. coli apresentaram multirresistência e a maioria apresentou maior percentagem de multirresistência contra 2 a 3 e contra 10 antimicrobianos. Não foi verificado estatisticamente relação entre os padrões de virulência e os padrões de resistência aos antimicrobianos entre as amostras
The present study was conducted between january 2012 to january 2013 on dairy farms of Dracena city region, São Paulo. During the period, 800 samples of faeces were collected with rectal suabs from dairy cattle cows. Those samples were taken to the laboratory of microbiology of Dracena Experimental Campus, where 561 samples were isolated and identified for Escherichia coli. After the DNA from the samples were extracted by the boiling method and with PCR the genetic material was amplified to detect the presence of virulence genes from STEC, shiga-like toxin producer E. coli, on 446 samples. Of those samples, 90 were carriers of the stx1 gene, 97 of the gene stx2, 45 of the gene eae, 37 of the genes stx1 and stx2, 110 of the genes stx1 and eae, 67 of the genes stx2 and eae. Also were isolated 115 samples that did not carry none of the virulence genes from STECs of the study. All the E. coli isolates of each virulence gene were evaluated for resistence to 10 antibiotics. The percentual of resistence were higher for lincomycin, penicillin and novobiocin and lower for ampicillin, neomycin and tetracycline. A serogroup test was made, of which the most frequent among isolates carrying the virulence gene stx1 were O119 and O114; of the gene stx2 were serogroups O8 and O9; and of the gene eae were the serogroups O9, O8 and O127. All the E. coli isolates presented multirresistence and most isolates presented more percentage of multirresistence against 2 to 3 and against 10 antibiotics. Was not verified statistically relationship between virulence patterns and patterns of antimicrobial resistance among the samples
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Assumpção, Gustavo Lacerda Homem. « Avaliação dos padrões de susceptibilidade antimicrobianas e sorogrupos de cepas de Escherichia coli isoladas de bovinos leiteiros, portadoras e não portadoras dos genes stx1, stx2 e eae / ». Jaboticabal, 2013. http://hdl.handle.net/11449/94796.
Texte intégralRésumé :
Orientador: Everlon Cid RigobeloBanca: Hélio José Montassier
Banca: José Carlos Rende
Resumo: O presente estudo foi realizado no período de janeiro de 2012 a janeiro de 2013 em fazendas leiteiras da região de Dracena, São Paulo. Durante o período, foram coletadas 800 amostras de fezes com suabes retais em vacas leiteiras. Essas amostras foram levadas para o Laboratório de Microbiologia do Campus Experimental de Dracena, onde foram isoladas e identificadas 561 amostras para Escherichia coli. Após o isolamento foram extraídos os DNAs de todas as amostras pelo método da fervura e por PCR o DNA foi amplificado para se detectar a presença dos genes de virulência de E. coli pertencentes ao grupo STEC, produtora de toxina tipo shiga em 446 amostras. De todas as cepas isoladas 90 eram portadoras do gene stx1, 97 do gene stx2, 45 do gene eae, 37 dos genes stx1 e stx2, 110 dos genes stx1 e eae e 67 dos genes stx2 e eae. Foram isoladas também 115 cepas que não eram portadoras de nenhum dos genes de virulência de STECs do estudo. Todos os isolados de E. coli portadores de cada gene de virulência foram avaliados quanto a resistência frente a 10 antimicrobianos. Os percentuais de resistências aos antimicrobianos foram maiores para a lincomicina, penicilina e novobiocina e menores para ampicilina, neomicina e tetraciclina. Foram identificados os sorogrupos, dos quais os mais frequentes entre os isolados portadores do gene de virulência stx1 foram o O119 e O114; do gene de virulência stx2 foram os sorogrupos O9 e O8; e do gene de virulência eae foram os sorogrupos O9, O8 e O127. Todos os isolados de E. coli apresentaram multirresistência e a maioria apresentou maior percentagem de multirresistência contra 2 a 3 e contra 10 antimicrobianos. Não foi verificado estatisticamente relação entre os padrões de virulência e os padrões de resistência aos antimicrobianos entre as amostras
Abstract: The present study was conducted between january 2012 to january 2013 on dairy farms of Dracena city region, São Paulo. During the period, 800 samples of faeces were collected with rectal suabs from dairy cattle cows. Those samples were taken to the laboratory of microbiology of Dracena Experimental Campus, where 561 samples were isolated and identified for Escherichia coli. After the DNA from the samples were extracted by the boiling method and with PCR the genetic material was amplified to detect the presence of virulence genes from STEC, shiga-like toxin producer E. coli, on 446 samples. Of those samples, 90 were carriers of the stx1 gene, 97 of the gene stx2, 45 of the gene eae, 37 of the genes stx1 and stx2, 110 of the genes stx1 and eae, 67 of the genes stx2 and eae. Also were isolated 115 samples that did not carry none of the virulence genes from STECs of the study. All the E. coli isolates of each virulence gene were evaluated for resistence to 10 antibiotics. The percentual of resistence were higher for lincomycin, penicillin and novobiocin and lower for ampicillin, neomycin and tetracycline. A serogroup test was made, of which the most frequent among isolates carrying the virulence gene stx1 were O119 and O114; of the gene stx2 were serogroups O8 and O9; and of the gene eae were the serogroups O9, O8 and O127. All the E. coli isolates presented multirresistence and most isolates presented more percentage of multirresistence against 2 to 3 and against 10 antibiotics. Was not verified statistically relationship between virulence patterns and patterns of antimicrobial resistance among the samples
Mestre
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Hammarin, Gabriella. « STS on STS : A Perspective of Science and Technology Studies on the STS Field Itself ». Thesis, Uppsala universitet, Ekonomisk-historiska institutionen, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-158088.
Texte intégralRésumé :
STS, today the abbreviation for Science and Technology Studies (formerly Science, Technology and Society), is an elusive field characterized by widely varying applications and intents, highly dependent on individual people and facets, yet sharing some common aims and practices. STS has risen since the 1960s and this empirical study presents a view on STS today and a discussion on how it has developed by the analysis of five different representatives from different locations in the field of STS.
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Ferreira, Tatiane Aparecida. « Estudo do potencial adjuvante dos toxóides Stx1 e Stx2 de Escherichia coli em preparações com antígenos de vesículas de membrana externa de Neisseria meningitidis B em camundongos BALB/c ». Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-30042010-095023/.
Texte intégralRésumé :
As vacinas antimeningocócicas têm se demonstrado efetivas contra os sorogrupos A e C, no entanto ainda não existe vacina contra o sorogrupo B devido à similaridade entre a estrutura capsular do polissacáride B e o ácido polisiálico que faz parte do tecido cerebral humano, podendo levar à autoimunidade. O objetivo deste estudo foi investigar as propriedades adjuvantes dos toxóides Stx1 e Stx2 (STEC) de Escherichia coli, administrados em preparações antigênicas com vesículas de membrana externa nativa (NOMV) de Neisseria meningitidis B, comparando duas vias de imunização prime-boost ou intramuscular, em camundongos BALB/c com idade entre 6-8 semanas. A determinação dos níveis de anticorpos empregando a técnica de ELISA, mostrou elevadas concentrações de anticorpos IgG em soros de animais imunizados pela via intramuscular com Stx1+NOMV, mas não com NOMV, o que sugere que por esta via (intramuscular apenas) Stx1 possa ter atuado como adjuvante. No ensaio de Immunoblotting, soros de animais imunizados com Stx1+NOMV reconheceram maior número de antígenos de NOMV quando comparado ao grupo que recebeu Stx2+NOMV. O sistema prime-boost mostrou-se efetivo quando comparamos os níveis de anticorpos presentes no soro após a dose intramuscular (reforço), entretanto, não melhor do que quando utilizamos duas doses apenas pela via intramuscular. Este estudo poderá contribuir no desenvolvimento de tecnologias associadas a novas preparações antigênicas utilizando antígenos de membrana externa de N. meningitidis B , empregando toxóides como adjuvantes.The meningococcal vaccines have been shown to be effective against serogroups A and C, however there is still no vaccine against serogroup B. The capsular polysaccharide from serogroup B meningococci polysialic acid moiety mimetic of many human glycoproteins including the neural cell adhesion molecules and may lead to autoimmunity. This study aimed to investigate the adjuvant properties of toxoids Stx1 and Stx2 (STEC) from Escherichia coli and native outer membrane vesicles (NOMV) of Neisseria meningitidis B, comparing two ways of immunization prime-boost or only intramuscular in BALB/c mice. The results showed high concentrations of IgG antibodies in sera of animals immunized intramuscularly with Stx1+NOMV, suggesting that in this way may have Stx1 acted as an adjuvant. In the Immunoblotting assay, sera from animals immunized with Stx1+NOMV recognized more antigens of NOMV when compared to the group that received Stx2+NOMV. The prime-boost was effective however, no better than only two doses intramuscularly. This study may contribute to the development of new technologies and strategies against N. meningitidis B employing toxoids as adjuvants.
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Retherford, Kurt D. « Io's aurora HST/STIS observations / ». Available to US Hopkins community, 2002. http://wwwlib.umi.com/dissertations/dlnow/3068201.
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Weaver, Racquel D. « An Assessment of Sexually Transmitted Disease Knowledge Among 7th Grade Students ». ScholarWorks, 2015. https://scholarworks.waldenu.edu/dissertations/610.
Texte intégralRésumé :
Sexually transmitted diseases (STDs) continue to remain a public health concern in the United States, especially among young people. Levels of knowledge with regard to STDs have been investigated in prior research; however, these investigations have been limited primarily to older adolescents and young adults. Grounded in the social cognitive and subjective culture theories, this quantitative, cross-sectional study assessed STD knowledge (other than HIV/AIDS) among 7th grade students attending a public middle school in the United States. Demographic differences (age, gender, and ethnicity) in STD knowledge were examined to determine if these demographic variables predict STD knowledge scores and if the Sexually Transmitted Disease Knowledge Questionnaire (STD-KQ) is a valid and reliable instrument among this study population. Chi-square analysis demonstrated that STD knowledge scores significantly differed by age only: Twelve-year-olds had higher STD scores than did 13-year-olds, contrary to research in older adolescents, which may be the result of confounding factors that warrant further investigation. Multiple regression analysis showed that age, gender, and ethnicity were not associated with STD knowledge scores. The STD-KQ was found to have face validity as well as high consistency and reliability among all questions related to STDs other than HIV/AIDS using Crohnbach's alpha. Content validity for individual STD-KQ items was shown using Lawshe's content validity ratio and subject matter experts. Results of the study support positive social change and highlight the need for earlier STD education, other than HIV/AIDS, with middle school children and the need to examine other factors that may impact STD knowledge within this age group.
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Howard, Stacy F. « Strategies for decreasing sexually transmitted infections in adolescent females ». Honors in the Major Thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1419.
Texte intégralRésumé :
This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.Bachelors
Nursing
Nursing
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Sutton, Eva Marie Ganong Lawrence H. « Undergraduate human sexuality textbooks coverage of STDs / ». Diss., Columbia, Mo. : University of Missouri--Columbia, 2008. http://hdl.handle.net/10355/5731.
Texte intégralRésumé :
The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on October 4, 2009). Thesis advisor: Dr. Lawrence Ganong. Includes bibliographical references.
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Amorim, Flavia Ferreira. « Remoção dos contaminantes orgânicos β-estradiol e saxitoxinas (STX, Neo-STX e dc-STX) por meio de nanofiltração : avaliação em escala de bancada ». reponame:Repositório Institucional da UnB, 2007. http://repositorio.unb.br/handle/10482/1853.
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O presente trabalho teve como objetivo avaliar a remoção dos contaminantes orgânicos β- estradiol e das saxitoxinas (STX, dc-STX e Neo-STX) por nanofiltração. A escolha dos contaminantes foi motivada pela crescente presença desses compostos em mananciais de abastecimento e o potencial de causar danos à saúde humana mesmo em baixas concentrações. Pesquisas demonstram que a eficiência de remoção pelo tratamento convencional não é suficiente para evitar os possíveis efeitos adversos e por isso um tratamento avançado precisa ser considerado para remoção desses contaminantes. Os ensaios de nanofiltração foram realizados em um sistema com dispositivo de separação em membranas de fluxo tangencial, em escala de bancada, com recirculação do concentrado. A pressão de trabalho aplicada no sistema foi de 689kPa e a velocidade tangencial constante foi de aproximadamente 0,4m/s. A temperatura da água de alimentação foi mantida em cerca de 25°C. Foram testados dois tipos de membranas, uma de acetato de celulose e outra composta de poliamida sobre suporte de polissulfona. Dois tipos de águas de estudo foram utilizados e, além disso, a influência do valor do pH da água no processo de remoção dos contaminantes foi avaliada. A água de estudo tipo I consistia de água deionizada contaminada com β-estradiol em concentração constante de aproximadamente 10 μg/L. A água tipo II consistia de água deionizada contaminada com saxitoxinas originadas da cepa de Cylindropermopsis raciborskii. A concentração de saxitoxinas foi variável, dependendo da concentração resultante do cultivo da cianobactéria. A quantificação do β-estradiol foi realizada pelo método “Enzyme Linked Immuno Sorbent Assay” (ELISA) e das saxitoxinas pela Cromatografia Líquida de Alto Desempenho (CLAE). Os resultados dos ensaios demonstraram que o mecanismo de adsorção contribuiu para remoção tanto do β-estradiol, quanto das saxitoxinas. As remoções de β-estradiol foram maiores para a membrana composta do que para a membrana de acetato de celulose, no entanto a porcentagem de remoção real não pode ser avaliada, pois não se alcançou o equilíbrio na remoção. Para as saxitoxinas as remoções foram maiores para a membrana de acetato de celulose do que para a membrana composta. A elevação do valor de pH promoveu a redução do fenômeno da adsorção na membrana para os contaminantes estudados e influenciou positivamente o processo, elevando bastante as eficiências de remoção de β-estradiol e saxitoxinas. _______________________________________________________________________________ ABSTRACT
The aim of work was to investigate the removal of β-estradiol and saxitoxins (STX, dc- STX and Neo-STX) by nanofiltration. These contaminants were selected due to its growing detection in drinking water reservoirs and their potential risk to human health, even at low concentrations. According to the literature, these substances are only poorly removed by conventional water and wastewater treatments and it is necessary to consider advanced treatment processes for efficient removal. The experiments were carried out in a laboratory scale cross-flow filtration system with recirculation of the concentrate. The applied pressure was fixed at 689kPa and the constant cross-flow velocity was 0,4m/s. The temperature of feed solution was kept at about 25°C. Two nanofiltration membranes, polyamide thin film composite and cellulose acetate, were tested for the removal of β-estradiol and saxitoxins. The influence of pH solution on contaminants retention was also examined. Feed water type I was prepared by spiking estradiol into mili-Q water to make up a solution containing about 10μg/L of β-estradiol. Feed water type II contained variable concentration of saxitoxins extracted from Cylindropermopsis raciborskii culture. β-estradiol and saxitoxins concentrations were quantified by Enzyme Linked Immuno Sorbent Assay (ELISA) method and High Performance Liquid Cromatography (HPLC), respectively. The results suggest that the adsorption mechanism contributes for the removal of both β- estradiol and saxitoxins by nanofiltration. The thin film composite membrane exhibited higher performance in terms of β-estradiol rejection, but the actual percentage removed was not obtained because the steady-state was not reached. The cellulose acetate exhibited a higher performance in terms of the saxitoxins rejection. The adsorption of both β- estradiol and saxitoxins on the membranes decreased when the pH of the feed water was increased. At the higher pH value, β-estradiol and saxitoxins rejections also increased.
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Xu, Xuefang. « Regulation of type III secretion in enterohaemorrhagic Escherichia coli ». Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/5941.
Texte intégralRésumé :
Enterohaemorrhagic Escherichia coli (EHEC) strains are associated with gastrointestinal and severe systemic disease in humans. EHEC O157:H7 is the most common serotype causing human infections in North America and the UK. Human infections mainly originate from cattle, through either direct contact with infected animals or indirectly through contamination of food or water with animal faeces. From the sequencing of EHEC O157 strains, it is clear that the genomes contain multiple prophages, many of them cryptic, which define this E. coli pathotype. These regions include the locus of enterocyte effacement (LEE) which is a critical horizontally acquired pathogenicity island and encodes a type III secretion system (T3SS). The T3SS translocates effector proteins into epithelial cells that enable tight attachment to these host cells and also modify innate responses and other cellular functions to promote persistence in the animal host. The T3SS is essential for the colonisation of cattle by EHEC O157 where it is localised to the terminal rectum. The regulation of T3S is complex with many regulators and environmental factors already identified. Previous work has demonstrated marked variation in the levels of T3S among EHEC O157 strains. The aim of this research was to further investigate the regulation of T3S towards two objectives: (1) to understand the localisation of EHEC O157 at the terminal rectum of cattle; (2) to understand the strain variation in T3S. (1) In relation to rectal and mucosal colonisation, established aerobic/anaerobic regulators were investigated including arcA, fnr, narX, narQ. Briefly, arcA, fnr, narX, narQ were deleted in an E. coli O157 strain ZAP198 by lambda red recombination. Apart from the fnr mutant which showed lower levels of T3S, the remaining mutants displayed similar T3S protein levels compared to the wild type strain. In addition, no significant changes in adherence and A/E lesion formation capacity were measured for the mutants following interaction with bovine epithelial cells. (2) Strain secretion variation was approached in two ways; the first was to control expression from the LEE1 operon, required for T3S expression, in order to both induce expression and examine the importance of downstream regulation. The second was to investigate variation in T3S between different phages types of EHEC O157. While attempts to construct an inducible T3SS were not successful, intermediate strains made in the process have been useful to dissect how regulators being studied in the laboratory control T3S. The main novel insights from the research have come from examining T3S in different EHEC O157 phage types. We found that the average level of T3S in PT 21/28 strains was lower than in PT 32 strains. Interestingly, most (90%) of PT 21/28 strains contained both Stx2 and Stx2c phages. In contrast, only 28% of PT 32 strains had both phages. Taken together, this raised the possibility that Stx phage integration might have a repressive impact on T3SS regulation in E.coli O157:H7. This hypothesis was addressed using a number of different approaches. Deletions of Stx phages were constructed and these had increased levels of T3S when compared to the parental strains. This phage regulation of T3SS was confirmed in an E. coli K12 background by examining an induced LEE1 reporter in the presence and absence of a transduced Stx2 phage. In addition, it was shown that deletion of the CII phage regulator led to increased T3S and may contribute to the Stx phage repression reported above. This work demonstrates for the first time that Stx phage integration represses T3S expression. It is proposed that this control may limit immune exposure of this critical colonisation factor and that the repression actually allows activation by prophage encoded regulators, including PchA/B, that co-ordinate T3S and non LEE-encoded effector expression to promote epithelial cell colonisation.
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Burianyk, Natalia. « Incarceration and death, the poetry of Vasyl' Stus ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq22957.pdf.
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Lampe, Birgit [Verfasser]. « Transkranielle Einzelimpulsstimulation (sTMS) bei akustischer Verbgenerierung / Birgit Lampe ». Köln : Deutsche Zentralbibliothek für Medizin, 2012. http://d-nb.info/1024715361/34.
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Achilli, A. « DIALOGO E SPERIMENTAZIONE : LA LIRICA DI VASYL' STUS ». Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/257953.
Texte intégralRésumé :
My dissertation explores the poetry of Vasyl' Stus (1938-1985), a major Ukrainian writer and intellectual of the second half of the 20th century. This work aims at presenting the evolution of Stus' poetic oeuvre from his beginnings in the late Fifties up to his mature poetry of the Seventies. Moreover, it inquires the complex intertextual network of Stus' dialogue with Ukrainian, Russian, and German literature.
The first chapter includes a brief sketch of Stus' biography, a discussion of the cultural setting of his human and artistic growth, as well as a critical survey of secondary literature on Stus' life and work. Stus' move to Kyiv at the beginning of the Sixties coincides with the final phase of the Thaw. The historical and literary specificity of the Ukrainian shistdesiatnytstvo, which promoted a fundamental and manifold renewal of Ukrainian culture, is at the core of the chapter. The history of Stus' reception shows how his complex and highly intellectual modernist poetical heritage has not been aptly inquired into by critics.
The second chapter deals with Stus' literary essays and letters, with particular regard to his frequent remarks on literature. Stus' dissatisfaction with several trends in the development of Ukrainian literature clearly shows his willingness to contribute actively to its modernization. His many observations on the poetry of Rainer Maria Rilke, Boris Pasternak and other writers confirm his deep interest in their work and justify the search for intertextual links with them in his own production.
The third chapter analyzes Stus' poetry, starting from his juvenilia, which include his early collections Delo №13 / BE1339 and Kruhovert', then focusing on Zymovi dereva and Veselyi cvyntar from the late Sixties, and eventually turning to his both masterpieces Chas tvorchosti / Dichtenszeit and Palimpsesty from the Seventies.
The fourth chapter is dedicated to a discussion of Stus' modernist poetics in the context of the history of European and Ukrainian poetry of the 20th century. This implies a summarization of the intertextual knots identified in the previous part of the dissertation, with the aim of identifying the main features of Stus' dialogue with his preferential interlocutors, such as Rilke, Pasternak, Cvetaeva, and Shevchenko.
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Barron, Paul E. « The impact of a dedicated Science-Technology-Society (STS) course on student knowledge of STS content ». Related electronic resource:, 2005. http://proquest.umi.com/login?COPT=REJTPTU0NWQmSU5UPTAmVkVSPTI=&clientId=3739.
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Resende, Pedro Manuel Oliveira e. Sousa de Albergaria. « Interesse do estudo de STRs na investigação médico-legal ». Master's thesis, Universidade do Porto. Reitoria, 2003. http://hdl.handle.net/10216/10496.
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Resende, Pedro Manuel Oliveira e. Sousa de Albergaria. « Interesse do estudo de STRs na investigação médico-legal ». Dissertação, Universidade do Porto. Reitoria, 2003. http://hdl.handle.net/10216/10496.
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Gurioli, Laura. « Protocollo di autenticazione STS e IKE ». Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/14127/.
Texte intégralRésumé :
Lo scambio delle chiavi di Diffie-Hellman fu il primo sistema a permettere a due interlocutori di condividere una chiave segreta senza l'utilizzo di un canale sicuro.
La debolezza più grande di questo sistema è rappresentata dall'attacco "Man in the middle", in cui l'avversario riesce a porsi in mezzo alla comunicazione e impersonare i due interlocutori. Il protocollo STS (Station To Station) nasce nel 1987 per garantire maggiore sicurezza al protocollo base di Diffie-Hellman. Esso, grazie all'utilizzo della firma digitale, aggiunge l'autenticazione dei soggetti coinvolti nello scambio, impedendo così l'attacco Man in the middle.
Rimangono, però, ancora possibili attacchi come quello di Lowe. Il protocollo STS, inoltre, è una delle basi per il protocollo di autenticazione standard per la sicurezza Internet, chiamato "Internet Key Exchange (IKE)".
A questo proposito introduciamo lo standard ISO/OSI, composto da 7 livelli, e il protocollo IP che lavora al livello 3. Quest'ultimo si occupa dell'indirizzamento e instradamento dei dati che viaggiano in rete. IP è stato migliorato in IPSec per essere più resistente agli attacchi.
L'autenticazione delle parti in IPSec è dovuta al protocollo IKE (Internet Key Exchange). Esistono diverse varianti di questo protocollo, in questa tesi vedremo soltanto le modalità basate sulla firma digitale.
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Facco, Giancarlo <1987>. « Management dell'innovazione. Il caso aziendale STS ». Master's Degree Thesis, Università Ca' Foscari Venezia, 2013. http://hdl.handle.net/10579/3387.
Texte intégralRésumé :
La tesi tratterà due tematiche principali. In una prima parte del lavoro si illustreranno le caratteristiche dell'innovazione tecnologica e dei suoi mercati, ossia le sue fonti e le sue dinamiche di manifestazione. Nella seconda parte del lavoro, la più approfondita, si mostreranno le problematiche che un'impresa deve concretamente affrontare nella pratica gestionale, per individuare e implementare una strategia per gestire l'innovazione. Tale parte del lavoro analizzerà questa tematica, producendo delle osservazioni inerenti diverse branche manageriali: organizzazione, team di sviluppo, marketing, processo di sviluppo ecc.
La tesi si concluderà con una parte empirica, che conferma la validità delle tesi teoriche sulla gestione dell'innovazione sostenute nel resto del lavoro. Tale parte empirica, riguarderà l'analisi delle modalità per riconfigurare il modello di business e la strategia tecnologica dell'impresa considerata, a fronte di mutate esigenze competitive di mercato. Le osservazioni e i dati raccolti sulla prassi gestionale di questa realtà aziendale, verranno riportati e commentati nella parte empirica. Essi riguarderanno soprattutto la modalità di implementazione di una strategia tecnologica per l'innovazione da parte dell'impresa considerata.
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Thibaut, Saltet De Sablet. « Production de Shiga-toxine Stx2 par les Escherichia coli entérohémorragiques : influence du génotype stx2, régulation par le quorum sensing et le microbiote intestinal ». Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2007. http://tel.archives-ouvertes.fr/tel-00509224.
Texte intégralRésumé :
Les Escherichia coli entérohémorragiques (EHEC) sont responsables de toxi–infections alimentaires conduisant à des colites hémorragiques pouvant se compliquer d'un syndrome hémolytique et urémique. Le facteur majeur de pathogénicité est la production de Shiga-toxines (Stx), dont la toxine Stx2. Nous avons étudié la production de toxine Stx2 in vitro par des souches STEC provenant de diverses origines (bovine ou clinique), appartenant à divers séropathotypes, et codant pour différents variants Stx2. Nous avons montré que les souches O157:H7 les plus pathogènes possèdent le variant stx2 et produisent de fortes quantité de Stx2 en conditions basales comme en présence d'un inducteur du système SOS. Les souches non-O157 présentant ces caractéristiques pourraient représenter un risque pour la santé humaine. Nous avons ensuite étudié l'effet de molécules présentes dans le tube digestif sur la synthèse de Stx2 par E. coli O157:H7. Les auto-inducteurs AI-2 et AI-3 du quorum sensing, produits par le microbiote intestinal, n'influencent pas la synthèse de Stx2, non plus que l'hormone intestinale norépinéphrine. Cependant, la protéine régulatrice QseA impliquée dans une voie de signalisation par le quorum sensing serait un activateur transcriptionnel de stx2. Enfin, nous avons étudié la production de Stx2 par la souche EHEC O157:H7 EDL 933 dans un milieu se rapprochant le plus possible de celui rencontré in vivo par les EHEC, en particulier grâce à un modèle de rats associés au microbiote intestinal humain. Nous avons ainsi montré que le microbiote humain inhibe la transcription de stx2 par l'inhibition de la transcription de recA même lors de l'induction du système SOS, et que cette inhibition peut être en partie attribuée à l'espèce Bacteroides thetaiotaomicron.
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Saltet, de Sablet d'Estières Thibaut. « Production de shiga-toxine STX2 par les Escherichia coli entérohémorragiques : influence du génotype STX2, régulation par le quorum sensing et le microbiote intestinal ». Clermont-Ferrand 2, 2007. http://www.theses.fr/2007CLF21815.
Texte intégralRésumé :
Les Escherichia coli entérehémorragiques (EHEC) sont responsables de toxi-infections alimentaires conduisant à des colites hémorragiques pouvant se compliquer d'un syndrome hémolytique et urémique. Le facteur majeur de pathogénicité est la production de Shiga-toxines (Stx), dont la toxine Stx2. Nous avons étudié la production de toxine Stx2 in vitro par des souches STEC provenant de diverses origines (bovine ou clinique) appartenant à divers séropathotypes, et codant pour différents variants Stx2. Nous avons montré que les souches O157:H7 les plus pathogènes possédent le variant stx2 et produisent de fortes quantité de Stx2 en conditions basales comme en présence d'un inducteur du système SOS. Les souches non O-157 présentant ces caractéristiques pourraient représenter un risque pour la santé humaine. Nous avons ensuite étudié l'effet de molécules présentes dans le tube digestif sur la synthèse de Stx2 par E. Coli O157:H7. Les auto-inducteurs AI-2 et AI-3 du quorum sensing, produits par le microbiote intestinal, n'influencent pas la synthèse de Stx2, non plus que l'hormone intestinale norépinéphrine. Cependant, la protéine régulatrice QseA impliquée dans une voie de signalisation par le quorum sensing serait un activateur transcriptionnel de stx2. Enfin, nous avons étudié la production de Stx2 par la souche EHEC O157:H7 EDL 933 dans un milieu se rapprochant le plus possible de celui rencontré in vivo par les EHEC, en particulier grâce à un modèle de rats associés au microbiote intestinal humain. Nous avons ainsi montré que le microbiote humain inhibe la transcription de stx2 par l'inhibition de la transcription de recA même lors de l'induction du sustème SOS, et que cette inhibition peut être en partie attribuée à l'espèce Bacteroides thetaiotaomicron
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Johnson, Christina Carole. « Survey of the Great Kanawha River, West Virginia, for virulence related gene markers stx₁, stx₂, and eaeA ». Huntington, WV : [Marshall University Libraries], 2006. http://www.marshall.edu/etd/descript.asp?ref=693.
Texte intégralRésumé :
Theses (M.S.)--Marshall University, 2006.Title from document title page. Includes abstract. Document formatted into pages: contains xii, 117 p. including illustrations and map. Bibliography: p. 36-42.
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Svensson, Linn, et Sara Waern. « Knowledge of and attitudes to sexually transmitted diseases among Thai university students ». Thesis, Uppsala universitet, Institutionen för folkhälso- och vårdvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-202708.
Texte intégralRésumé :
Sexually transmitted diseases are a major problem among adolescents in Thailand, and seeing that unprotected sex is a growing trend, awareness must be increased. The aim of this study was to examine Thai students’ knowledge of and attitudes to STDs as well as if there are any differences in gender regarding these questions. A descriptive cross-sectional study was carried out at a private university in Bangkok, Thailand. The Health Belief Model was provided as theoretical framework. A questionnaire was answered voluntarily by 150 students, both male and female. The results showed that the students had low level of knowledge on STDs and their attitudes showed that they have many misconceptions regarding these issues. The study also showed that Thai students want to learn more about STDs and wish to receive this information from school. No major difference in gender was found. This study shows that additional education on STDs is needed among Thai adolescents. Further research in this area is acquired to get a wider perspective of Thai students’ knowledge on STDs, to help prevent future spreading of STDs.Sexuellt överförbara sjukdomar är ett stort problem hos ungdomar i Thailand och eftersom oskyddat sex är en växande trend bör detta uppmärksammas. Syftet med denna studie var att undersöka thailändska studenters kunskap om och attityder till sexuellt överförbara sjukdomar. Studien önskade även undersöka huruvida det fanns någon skillnad mellan könen. En deskriptiv tvärsnittsstudie gjordes på ett privat universitet i Bangkok, Thailand. Health Belief Model användes som teoretiskt ramverk. Ett frågeformulär besvarades frivilligt av 150 manliga och kvinnliga studenter. Resultatet visade att studenterna hade bristande kunskaper om sexuellt överförbara sjukdomar. Deras attityder visade att studenterna hade många felaktiga uppfattningar i frågan. Studien visade även att de thailändska studenterna vill lära sig mer om sexuellt överförbara sjukdomar och önskar att få denna information ifrån skolan. Studien visade inga stora skillnader mellan könen. Denna studie visar att ytterligare kunskaper om sexuellt överförbara sjukdomar hos thailändska ungdomar behövs. Ytterligare forskning inom området är önskvärt. Detta för att få ett bredare perspektiv om thailändska studenters kunskaper om sexuellt överförbara sjukdomar, för att bidra till att förebygga ytterligare smittspridning.
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PAIVA, JÚNIOR Sérgio de Sá Leitão. « DNAstr.com : ferramenta estatística aplicada à genética forense ». Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/17714.
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Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-08-19T12:38:39Z
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Tese - Sergio de Sa Leitao.pdf: 2555306 bytes, checksum: 9cf4a027de7926b4d5fc1af1503bbf91 (MD5)Made available in DSpace on 2016-08-19T12:38:39Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese - Sergio de Sa Leitao.pdf: 2555306 bytes, checksum: 9cf4a027de7926b4d5fc1af1503bbf91 (MD5) Previous issue date: 2016-03-15
A introdução do uso de STRs (Short Tandem Repeat) como uma ferramenta para identificação humana, revolucionou a área forense nos últimos 20 anos. Muitos laboratórios de biologia molecular passaram a oferecer o serviço de genotipagem com o objetivo de identificação individual tanto no âmbito forense. O serviço de genotipagem é finalizado na emissão de um laudo que, em muitos casos, será utilizado em tribunais e serve como prova em conflitos na justiça, por isto o laudo deve ser isento de erros e para garantir a minimização de erros nas conclusões dos laudos é necessário um grande controle por parte do laboratório, desde a coleta das evidências passando pela genotipagem até os cálculos estatísticos. O objetivo deste trabalho foi criar uma ferramenta destinada ao uso de laboratórios de genotipagem com foco forense. O DNAstr.com é um software construído na plataforma web que foca a automatização das etapas de cadastro até a emissão do laudo, permite a integração com outros aplicativos e equipamentos do laboratório, faz análises estatísticas do banco de dados e aplica alguns dos princípios estatísticos dos softwares utilizados na literatura para a resolução de casos de paternidade e análise de mistura.
The introduction of the use of STR (Short Tandem Repeat) as a tool for human identification has revolutionized forensic science in the last 20 years. Many molecular biology laboratories began offering the genotyping service with the individual identification goal in civil and forensic context. The genotyping service terminates producing a report, which in most cases, will be used in courts and will serve as evidence of justice disputes. Therefore, the report should not contain mistakes, and to ensure the minimization of errors in the conclusions of the reports is needed a lot of control by the laboratory from genotyping to the statistical calculations. The objective was to create a tool, oriented to the use of genotipage laboratories. The DNAstr.com is software that facilitates the creation of reports, automating the steps to register and report emission, allows integration with other applications and laboratory equipment, makes analyzes database statistics and apply some of the principles of statistical software used in the literature to resolve paternity cases, and mixture analysis.
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Deli, Fatma. « A Technostructure Proposal For Online Delivery Of Stps Graduate Program ». Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/12604926/index.pdf.
Texte intégralRésumé :
The purpose of this thesis is finding out whether offering an Online STPS Graduate Program with a tuition fee is feasible or not. Firstly, definition and brief history of distance education is given. Secondly, distance education applications in the world and in Turkey are studied. The main part of the thesis is the cost analysis made about the online delivery of STPS Graduate Program. The cost items of offering an online course are determined and then specific cost values are assigned to these items. By determining the cost items and related cost values, course development cost is calculated. In the course development cost calculation, fixed and variable costs are seperated. Fixed cost are the set-up costs that do not depend on any variable. Variable costs on the other hand are the costs that change with the number of students attending to the online course. A specific price value ( 100$ ) is assigned as the tuition fee for one credit hour of an online course. At the end of the cost analysis, the number of students required to meet the total cost of an online course is calculated. In addition, a questionnaire made on STPS students by STPS department is used in the thesis. The results of the questionnaire and the cost analysis are combined in order to analyze the feasibility of offering an online STPS Graduate Program.
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Benyamin, Kangsah Benedictus [Verfasser], et Jochen [Akademischer Betreuer] Beister. « Structural Decomposition of STGs / Benedictus Benyamin Kangsah. Betreuer : Jochen Beister ». Kaiserslautern : Technische Universität Kaiserslautern, 2015. http://d-nb.info/1067842209/34.
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Alday, Parejo Juan. « Ganymede's hydrogen corona and FUV albedo from HST/STIS images ». Thesis, KTH, Rymd- och plasmafysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-223964.
Texte intégralRésumé :
Ganymedes är största månen i vårt Solsystem, och är ett föremål för intensiv vetenskaplig forskning under senaste decenier. Sedan 1998, STIS (Space Telescope Imaging Spectrograph) instrumentet ombord rymdteleskopet Hubble (HST) har observerat Ganymedes i UV ljus med våglängder mellan 1150 Å och 1730 Å i fem olika omgångar. Bilder av månen har tagits när Ganymedes var i olika positioner i sin bana. Detta gör det möjligt att jämföra båda hemisfärer av månen, och att undersöka eventuell tidsvariation. I denna rapport HST/STIS observationer av Ganymedes analyseras med målsättningen att undersöka månens exosfär bestående av atomär syre samt månens albedo i FUV våglänger. Väteexosfären, också kallad korona, förväntas sprida Lyman- ljuset vid 1216 Å, som kan observeras av STIS. Observationer i denna våglängd analyseras och en modell är framtagen för olika källor som bidrar vid denna våglängd. En uppskattning görs också av en eventuell absorption av Ganymedes emissioner i Jordens övre atmosfär, som kan uppgå till 85%. Jämförelse av modellen med bilder från HST/STIS tyder på att Ganymedes har en väteexosfär med ytdensiteten av (2-8) 103 cm3. Under Hubble kampanj 13328 har däremot betydligt lägre antal väteatomer detekterats, som kan bero på skillnader i magnetosfäriska omgivningen av månen jämfört med tidigare observationer. FUV albedo av månens yta har undersökts genom jämförelser av reflektansen vid olika våglängder, inklusive eventuella skillnader mellan olika hemisfärer. Vi finner att bakre (i förhållande till rörelsen i banan, som månen är låst i) hemisfären är ljusare än främre hemisfären för < 1600 Å. För längre våglängder, > 2000 Å, har motsatta resultat rapporterats tidigare, där främre hemisfären var ljusare. Detta tyder på att Ganymedes ytreflektans har en spektral inversion mellan 1600-2000 Å. Vi noterar även att ytreflektansen ökar med kortare våglängd för < 1400 Å, som kan bero på att ytans växelverkan med rymdpartiklar.Ganymede, the largest moon in our Solar System, has been a target for intensive scientific research during the past decades. Since 1998, the Space Telescope Imaging Spectrograph (STIS) onboard of the Hubble Space Telescope (HST) has observed it in five different HST campaigns, operating in a wavelength range between 1150-1730 Å. The images were obtained when Ganymede was located at different orbital phase, providing information about both the trailing and leading hemispheres, and allowing for the search of potential hemispherical and time variability. Here, we analyze Ganymede’s HST/STIS observations in the search for a hydrogen exosphere and the study of the far-ultraviolet (FUV) albedo at different wavelengths. The hydrogen corona is expected to scatter sunlight at the Lyman- wavelength (1216 Å), which is within STIS’ spectral range. We analyze the observations at this particular wavelength, and derive models for the different sources of emission that are expected to contribute to the signal. We also estimate the potential extinction of Ganymede’s coronal emissions in the Earth’s upper atmosphere, which can be up to 85%. The comparison between the HST/STIS images and the model allows us to detect the hydrogen exosphere, which we estimate to be in a range of approximately (2-8) 103 cm3. The atomic hydrogen abundance in Ganymede’s atmosphere during HST campaign 13328 appears to be significantly lower, which could be related to differences in the plasma magnetospheric environment. We study Ganymede’s FUV albedo comparing the reflectance at different wavelengths, and potential difference between leading and trailing hemispheres. We find out that the trailing hemisphere is brighter than the leading side for < 1600 Å. This dichotomy is opposite to the previous results reported for > 2000 Å, where the leading hemisphere is actually brighter. Hence, there is a spectral inversion of Ganymede’s surface reflectivity at some wavelength in the range 1600-2000 Å. We also find out that the reflectivity of the surface increases for < 1400 Å, which might be related to space weathering processes on the surface.
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Tabassum, Maisha. « Mechanical and Energy-Absorbing Properties of Shear-Thickening Fluids (STFs) ». Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/16856.
Texte intégralRésumé :
The absorption of dynamic energy during impact of a material is ubiquitous in industrial, biomedical and military applications. From suspension systems to shock absorbers, the ability to divert or dissipate dynamic energy imposes many challenges in developing these systems. Some typical complex composite fluids, such as shear-thickening fluids (STFs), play a vital role in these challenges. STFs, classified as non-Newtonian fluids, are special fluidic composites of dense suspensions which dramatically change their viscosity when subjected to a change in shear rate or stress. These fluidic composite materials display unusual phase transitions between liquid and “solid” phases, due to recoverable changes in viscosity at a critical rate of shear. In recent years, STFs have stimulated much research interest, in which most studies have been focused on the rheological and energy absorption properties of fabrics soaked with STF under impact. The fundamental knowledge of STFs after their shear-thickening transition is still unarticulated. Without full understanding of the fundamental structure-property relationships of STFs after shear-thickening transition it would not be able to design and optimize a material system with STFs, nor could cost-effective development of STFs as energy-absorbing materials be achieved. The aim of the studies in this thesis is to establish fundamental knowledge in developing STFs as adaptive energy-absorbing materials in practical applications. The studies establish methods and approaches for investigating and characterizing the mechanical as well as the energy-absorbing/dissipation properties of a STF systematically after the shear-thickening transition. The STF adopted in this work was composed of 58 vol.% dispersion of styrene/acrylate particles in ethylene glycol. Microscopic examination was conducted to characterize the size, geometry and distribution of styrene/acrylate particles in the STF, and the rheological behaviours of the STF were measured. Double-cantilever-beam specimens with the STF as adhesive layer were adopted to characterize the mode-I fracture energy of the STF at different crack opening displacement rates, following classic fracture mechanics. High-speed digital video-photography was used to observe the deformation behaviour of the STF. The load-displacement curve as well as the high-speed video recording confirmed that the STF showed a “solid” behaviour at high rates by developing rapid but stable crack extension that corresponded to fracture behaviour. The results indicated that the displacement rate and the STF thickness had a significant effect on the magnitude of the mode-I fracture energy of the STF. The fracture energy increased with an increase in the displacement rate, while a plateau value of about 240 J/m2 was observed at high rates. The measured fracture energy can be used as an effective parameter characterizing the crack resistance or the energy-absorbing capacity of the STF in the solid phase. The lap-shear strength and the braking energy of the STF were quantitatively characterized by a modified single-lap shear test method, performed by using two stainless steel adherends with the STF as adhesive layer. The results indicated that the shear rate had a significant effect on lap shear strength and the braking energy of the STF. Moreover, the studies were conducted to quantitatively characterize the energy absorption capacity of the STF under penetration impact and pull-out fracture at different impact or pull-out speeds. The results confirmed that the penetration rate again had a significant effect on the energy absorbing capacity of the STF. In comparisons with the energy absorbing behaviour of some cellular materials in the literature, the STF outperformed a polyurethane foam in terms of energy absorbing capacity. The ability of a STF to maintain its reversible shear-thickening transition behaviour depends on the integrity and durability of the STF. Cyclic dynamic loading at different magnitudes of durations was applied to the STF in order to quantitatively evaluate its aging behaviour. It was observed that cyclic dynamic loading affected the shear-thickening behaviour of the STF because of deterioration of the styrene/acrylate particles caused by abrasive wear during interaction between them, based on the rheological characterization. This research has delivered some new and original results for solutions to the outstanding problems in developing STFs as energy-absorbing materials. It should bring new opportunities for the development of new and advanced material systems with STFs for practical applications.
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Becker, Oliver. « Serielle Transformationen von XML ». Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2004. http://dx.doi.org/10.18452/15155.
Texte intégralRésumé :
Die Auszeichnungssprache XML definiert eine einfache Syntax für strukturierte Daten, die sich so applikationsübergreifend einsetzen lassen. Eine der wichtigsten Voraussetzungen für den Austausch solcher XML-Daten ist die Möglichkeit ihrerTransformation. Unter den derzeit verfügbaren Transformationsmethoden für XML hat die Sprache XSLT als W3C-Standard die größte Verbreitung gefunden. Allerdings skaliert XSLT nicht für große Datenmengen, da hier eine Gesamtsicht auf das XML-Dokument vorausgesetzt wird. Andere existierende Transformationsmethoden besitzen entweder die gleiche Eigenschaft oder erfordern die Programmierung auf der XML-fernen Ebene einer Programmiersprache. In dieser Arbeit wird mit STX eine Transformationssprache für XML entwickelt, die diese Lücke füllt. STX orientiert sich sehr stark an XSLT, verarbeitet jedoch ein XML-Dokument als Datenstrom. STX kann so prinzipiell beliebig große Dokumente transformieren. Die aus der Sprache XPath 2.0 des W3C abgeleitete STX-Pfadsprache (STXPath) trägt dabei der eingeschränkten Sicht auf die zu transformierenden Daten Rechnung, indem sie nur den Zugriff auf die Vorfahren des jeweiligen Kontextknotens ermöglicht. Zu den neuartigen Konzepten in STX zählen neben prozeduralen Eigenschaften vor allem Gruppen, Schnittstellen zu externen Transformationsprozessen, die komplexe Transformation von Zeichenketten sowie Sprachmittel zur Fehlerbehandlung. Diese Arbeit stellt Entwurfsmuster für die wichtigsten Transformationstypen in STX vor und demonstriert an drei Fallbeispielen den Einsatz in realen Projekten. Der dazu verwendete STX-Prozessor Joost verfügt zudem über standardisierteJava-Schnittstellen, die dessen Integration in bestehende Java-Applikationen erleichtern.The markup language XML defines a simple syntax for structured data that can be used across application boundaries. One of the most important prerequisites for the interchange of such XML data is the possibility of its transformation. Among the currently available transformation approaches for XML, the W3C standard XSLT has gained the biggest popularity. However, XSLT doesn''t scale for huge amounts of data because it requires an overall view to an XML document. Other existing transformation approaches either have the same character or require low-level programming using a general programming language. This PhD thesis introduces STX, an XML transformation language that fills this gap. STX is strongly geared to XSLT, though it processes an XML document as a stream. Therefore, STX is able to transform documents of any size. The STX path language (STXPath), derived from the W3C standard XPath 2.0, considers the restricted view to the input data and enables the access only to the ancestors of the current context node. The new concepts in STX include besides its procedural behaviour mainly groups, interfaces to external transformation processes, complex transformations of strings, as well as language means for error handling. This work introduces design patterns for the most important transformation types in STX and demonstrates three real-life scenarios. The STX processor Joost used for this purpose provides in addition standardized Java interfaces that facilitate its integration into existing Java applications.
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Shao, Jianfei. « STM/STS and BEES Study of Nanocrystals ». Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10526.
Texte intégralRésumé :
This work investigates the electronic properties of very small gold and semiconductor particles using Scanning Tunneling Microscopy/Spectroscopy (STM/STS) and Ballistic Electron Emission Spectroscopy (BEES). Complementary theoretical works were also performed. The first theoretical work was to calculate the quantized states in the CdS/HgS/CdS quantum-well-quantum-dot nanocrystals. An eight-band envelope function method was applied to this system. This method treats exactly the coupling between the conduction bands, the light-hole bands, the heavy-hole bands, and the spin-orbit split bands. The contributions of all other bands were taken into account using second order perturbation theory.
Gold nanocrystals with diameters of 1.5 nm have discrete energy levels with energy spacings of about 0.2 eV. These values are comparable to the single electron charging energy, which was about 0.5 eV in our experimental configuration. Since bulk gold doesnt have an energy gap, we expect the electron levels both below and above the Fermi level should be involved in the tunneling. Measured spectroscopy data have rich features. In order to understand and relate these features to the electronic properties of the nanocrystals, we developed a tunneling model. This model includes the effect of excited states that have electron-hole pairs. The relaxation between discrete electron energy levels can also be included in this model. We also considered how the nanocrystals affect the BEES current.
In this work an ultra-high vacuum and low-temperature STM was re-designed and rebuilt. The BEEM/BEES capabilities were incorporated into the STM. We used this STM to image gold nanocrystals and semiconductor nanocrystals. STS and BEES spectra of gold nanocrystals were collected and compared with calculations.
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Подольна, В. В., et В. А. Ярошенко. « STS-маркетинг як основа сучасного стратегічного маркетингу ». Thesis, Київський національний університет технологій та дизайну, 2015. https://er.knutd.edu.ua/handle/123456789/17323.
Texte intégral
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Sachetto, João Paulo. « Efeito do tratamento térmico de STx-1b-Li+ na condutividade de filmes de STx-1b-Li+ /Alginato de sódio ». Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18158/tde-06052016-084651/.
Texte intégralRésumé :
Neste trabalho foram estudados os efeitos causados pelo tratamento térmico na argila STx-1b-Li+ na condutividade de filmes argila/alginato de sódio. O argilomineral STx-1b foi submetido à substituição isomórfica do cátion Na+ por Li+ e posteriormente ao tratamento térmico em diferentes temperaturas. As argilas STx-1b-Li+ não tratada e tratada termicamente foram caracterizada por difração de raios-X (DRX) e termogravimetria (TG). As curvas TG mostraram que o argilomineral STx-1b-Li+ apresentou três perdas de massa que podem ser atribuídas à água adsorvida na argila, a água de hidratação dos íons Li+ e a água estrutural da argila. Para as argilas STx-1b-Li+ tratadas termicamente não foi observado a perda de massa associada à água quimicamente ligada aos contra-íons Li+. Estes resultados estão em concordância com os obtidos por DRX, onde observou-se uma diminuição no espaçamento interlamelar nas argilas tratadas termicamente. Em adição, foram preparados filmes de alginato de sódio com as argilas STx-1b-Li+ não tratada e tratada termicamente e estes foram caracterizados por calorimetria exploratória diferencia (DSC) e espectroscopia de impedância eletroquímica (EIE). As curvas DSC mostraram um aumento na temperatura de transição vítrea (Tg) dos filmes com o aumento da temperatura utilizada no tratamento das argilas. Este aumento nos valores de Tg é um indicativo que a mobilidade das cadeias diminuiu nos filmes polímero/argila que contém argilas tratadas em temperaturas mais elevadas. A espectroscopia de impedância eletroquímica (EIE) foi usada para avaliar-se a condutividade iônica dos filmes. Os resultados indicaram que os filmes contendo argilas que foram tratadas com temperaturas mais altas apresentaram menor condutividade.In this work the effects caused by the heat treatment in STx-1b-Li+ clay on the conductivity of sodium alginate/clay were studied. The clay mineral STx-1b was submitted to isomorphous substitution of the Na+ for Li+ cation and subsequently to heat treatment at different temperatures. The STx-1b-Li+ clays untreated and heats treated were characterized by X-ray diffraction (XRD) and Thermogravimetric Analysis (TG). The TG curve showed that the clay mineral STL-1b-Li+ had three mass losses which can be attributed to adsorbed water in the clay, the water of hydration of the Li+ ions and structural clay water. To STx-1b-Li+ clays heat treated there were no mass loss associated to the water chemically bound to Li+ counter ions. These results are in agreement with those obtained by XRD, which it was observed a decrease in interlayer spacing in the heat treated clay. In addition, they were prepared sodium alginate films with STx-1b-Li+ clays untreated and heat treated and these films were characterized by Differential Scanning Calorimetry (DSC) and Electrochemical Impedance Spectroscopy (EIS). DSC curves showed an increase in glass transition temperature (Tg) of the films with temperature increasing used in the treatment of clays. This increase in Tg value is an indicative that the mobility of the chains had decrease in the polymer/clay films which contains heat treated clays at higher temperatures. The electrochemical impedance spectroscopy (EIS) was used to evaluate the ionic conductivity of the films. The results indicate that films containing clays which have been treated at higher temperatures had lower conductivity.
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Svensson, Anna. « Jämställdhet som vitaliseringsstrategi : En studie om Unionen och Fackförbundet ST:s jämställdhetsarbete ». Thesis, Uppsala universitet, Statsvetenskapliga institutionen, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-339141.
Texte intégralRésumé :
This qualitative study examines whether, and to what extent, gender equality can be used for trade-union revitalisation purposes. The white-collar unions; Unionen and Fackförbundet ST, are two prominent cases of studying actor’s promotion of gender equality on the Swedish labour market. This study sets out two questions; In what ways do they work with gender issues? Why do they work with gender equality - Is it being used strategically or because they think that it is an important issue? The empirical study is based on twenty interviews with the respective union leadership, elected representatives and officials. The results of the study show that both unions are working on gender equality, because their members consider gender equality to be a priority. As regards the issue of gender equality as a strategy, my study shows that Unionen is working on gender equality as a strategy while Fackförbundet ST do not. Unionen do so that they can recruit a new group, namely young members. Therefore, my study shows that gender equality can be used as a union revitalisation strategy. The study also shows that union revitalisation strategies are contextual in the sense that strategies that work in countries with high female employment rates and high female union coverage, are different from strategies that work in countries with low female employment rates and low female union coverage.
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Lothringer, Joshua D., Björn Benneke, Ian J. M. Crossfield, Gregory W. Henry, Caroline Morley, Diana Dragomir, Travis Barman et al. « An HST/STIS Optical Transmission Spectrum of Warm Neptune GJ 436b ». IOP PUBLISHING LTD, 2018. http://hdl.handle.net/10150/626526.
Texte intégralRésumé :
GJ 436b is a prime target for understanding warm Neptune exoplanet atmospheres and a target for multiple James Webb Space Telescope (JWST) Guaranteed Time Observation programs. Here, we report the first space-based optical transmission spectrum of the planet using two Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) transit observations from 0.53 to 1.03 mu m. We find no evidence for alkali absorption features, nor evidence of a scattering slope longward of 0.53 mu m. The spectrum is indicative of moderate to high metallicity (similar to 100-1000x solar), while moderate-metallicity scenarios (similar to 100x. solar) require aerosol opacity. The optical spectrum also rules out some highly scattering haze models. We find an increase in transit depth around 0.8 mu m in the transmission spectra of three different sub-Jovian exoplanets (GJ 436b, HAT-P-26b, and GJ 1214b). While most of the data come from STIS, data from three other instruments may indicate this is not an instrumental effect. Only the transit spectrum of GJ 1214b is well fit by a model with stellar plages on the photosphere of the host star. Our photometric monitoring of the host star reveals a stellar rotation rate of 44.1 days and an activity cycle of 7.4 years. Intriguingly, GJ 436 does not become redder as it gets dimmer, which is expected if star spots were dominating the variability. These insights into the nature of the GJ 436 system help refine our expectations for future observations in the era of JWST, whose higher precision and broader wavelength coverage will shed light on the composition and structure of GJ 436b's atmosphere.
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Zaya, Johan, et Amanda Strömberg. « Optimering av St1s anläggning med integrering : Vägen till en hållbar utveckling ». Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-10278.
Texte intégralRésumé :
Många företag och industrier arbetar idag ständigt med att utveckla mindre miljöbelastande sätt att arbeta på, det beror på hårdare lagar och regler än tidigare angående utsläpp till miljön. Företag inventerar mycket resurser på ny forskning och ta fram nya metoder, allt för att bidra till en hållbar utveckling. St1 är ett av de företagen som vill vara med i arbetet för en hållbar utveckling och främst av förnybara bränslen. St1 har utvecklat en ny metod för framställning av etanol utav restråvaror från livsmedelsindustrin. Det bildas även drank som är en biprodukt som man kör ut till lantbruk för att använda som djurfoder eller vid produktion av biogas. Metoden benämns som Etanolix och den nya anläggningen på St1 Refinery AB är den senaste som fått namnet Etanolix 2.0. Syftet med rapporten är att visa hur integrering kan göras med en ny anläggning tillsammas med en redan befintlig och hur man kan ta till vara på outnyttjade resurser. I rapporten beskrivs de olika hjälpsystem som är integrerade med Etanolix 2.0 som processvatten, kvävgas samt ånga och kondensat. Det beskrivs också hur första året med Etanolix 2.0 i drift har gått och vad som varit utmaningarna vid uppstarten. Slutsatsen vi kom fram till är att Etanolix metoden bidrar till en hållbar utveckling och steget närmare att skapa framtida förnybara bränslen. Projekt Etanolix 2.0 är fortfarande i uppstartningsfasen och behöver ytterligare utveckling innan optimal produktion av etanol kan ske.
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Castro, Sarah Gurgel de. « Estudo de frequências alélicas de 15 STRs autossômicos na população paraibana ». Universidade Federal da Paraíba, 2014. http://tede.biblioteca.ufpb.br:8080/handle/tede/3657.
Texte intégralRésumé :
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Previous issue date: 2014-02-26Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Human identification is based on analyzing DNA through present throughout the genome molecular markers. These markers are transmitted from parents to offspring by heredity. STR markers are currently the most commonly used genetic markers in Forensic Genetics due to their high polymorphism, high reproducibility, possibility of being amplified by PCR in multiple copies in a single reaction, and minute quantities of DNA (1ng). The DNA test that allows individualization of the people is essential tool to the solution of forensic human identification cases, sex crimes, crime scenes (including or excluding suspects), mass disasters, and its result is presented in statistical calculations that consider allele frequency of markers used. So it is important to know the allele frequencies presented in the regional population so that the results are the most reliable possible. In this study , 15 autossomal markers (loci) STR or microsatellite (CSF1PO, D13S317, D16S539, D18S51, D19S433, D21S11, D2S1338, D3S1358, D5S818, D7S820, D8S1179, FGA, TH01, and VWA TPOX) were studied in 766 unrelated individuals paraibanos, demonstrating a tri population - hybrid formed Africans (25.86 %), Amerindian (6.81 %) and Europeans (67.33 %). The most informative were D21S11 and FGA, and were less informative TPOX, D7S820 and D13S317. The results are important for a database with allele frequencies found in Paraiba population can serve as a useful basis for calculating forensic practice in the State of Paraíba.
A identificação humana está baseada na análise do DNA através de marcadores moleculares presente em todo o genoma. Estes marcadores são transmitidos de pais para filhos por hereditariedade. Atualmente os marcadores STR são os marcadores genéticos mais utilizados em Genética Forense devido ao seu elevado polimorfismo, alta reprodutibilidade, possibilidade de serem amplificados por PCR em inúmeras cópias numa só reação e em mínimas quantidades de DNA (1ng). O exame de DNA que permite a individualização das pessoas é ferramenta indispensável à solução de casos forenses de identificação humana, crimes sexuais, locais de crime (incluindo ou excluindo suspeitos), desastres em massa, e tem seu resultado apresentado em cálculos estatísticos que consideram a frequência alélica dos marcadores usados. Por isso é importante o conhecimento das frequências alélicas apresentadas na população regional de forma que os resultados sejam os mais fidedignos possíveis. Neste trabalho, 15 marcadores autossômicos (loci) STR ou microssatélites (CSF1PO, D13S317, D16S539, D18S51, D19S433, D21S11, D2S1338, D3S1358, D5S818, D7S820, D8S1179, FGA, TH01, TPOX e vWA) foram estudados em 766 indivíduos paraibanos não aparentados, demonstrando uma população tri - hibrida, formada de africanos (25,86%), ameríndios (6,81%) e europeus (67,33%). Os mais informativos foram D21S11 e FGA, e os menos informativos foram TPOX, D7S820 e D13S317. Os resultados são importantes para que um banco de dados com as frequências alélicas encontradas na população paraibana possa servir de base de cálculo útil para prática forense no Estado da Paraíba.
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Garnett, Nomcebo Precious. « Prevalence of asymptomatic sexually transmitted infections : a retrospective review of screening data from Desmond Tutu HIV Centre clinical trial cohorts from 2012 to 2017, Cape Town ». Master's thesis, Faculty of Health Sciences, 2019. https://hdl.handle.net/11427/31649.
Texte intégralRésumé :
Background: The burden of Sexually transmitted infections (STIs) is high globally. The World Health Organisation (WHO) recommends syndromic management of these STIs, based on presentation with signs and symptoms, in resource-limited countries. Due to this syndromic approach, there is little current data on STI prevalence, including asymptomatic STIs, in high risk populations. Methods: We reviewed secondary data collected as part of the screening procedures of 6 clinical trials between 2012 and 2017 in Cape Town, South Africa. These trials recruited populations of different sexual orientation and gender, mostly key populations at risk of HIV and STI acquisition. Routine screening for STI symptoms and testing for Chlamydia, Gonorrhoea, Trichomonas, Syphilis and HIV was performed for all of the studies at screening/enrollment. Results: A total of 639 participants were screened; 411 (64.3%) self-identifying as female, 198 (31%) males, 29 (4.5%) transgender women and 01 (0.2%) transvestite. Median age was 20 years (IQR: 18-24), with the 15-24-year age category contributing 77% to the cohort. Laboratory testing diagnosed 239 (37.4%) people with STI infections in this cohort; only 28 (11.7%) people were symptomatic. 119 (88.8%) of Chlamydial, 64 (82.1%) of Gonorrhoeal, 23 (92%) of Trichomonal and 31(79.5%) of Syphilis infections elicited no signs and/or symptoms. Conclusion: A vast majority of STIs in this high-risk population were asymptomatic. Laboratory testing of causal organism was more reliable in diagnosing STIs than the use of signs and/or symptoms as recommended by WHO.
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Håkonsen, Christian, et Mikael Berkelund. « Development of a new drawing system for STS ». Thesis, Mälardalen University, School of Innovation, Design and Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-618.
Texte intégralRésumé :
An engineering firm which handles and constructs drawings needs well defined routines and structures which should be homogeneous through all the different departments. A common drawing system results in better quality and cooperation between the departments.
SAS Technical Services (STS) did not have a common drawing system which had led to development of different routines in the different regions and departments. Requested was development of new routines regarding engineering drawings, such as drawing numbering structure, revision and subscription routines, which standards to adhere to, custom made drawing templates and management of the drawings with belonging documents.
Each requested task was broken into minor tasks and analyzed. Solutions by different leading engineering companies were used for comparison and ideas.
All the tasks were collected and organized in one single document which is the result of the thesis; a drawing instruction.
The drawing instruction will after a learning phase ease the work for the STS engineers as all necessary information can be found in one single place. Also, work with contractors will be time-saving as the instruction can be handed out for guidance.
En ingenjörsfirma som hanterar och skapar mängder med ritningar behöver väldefinierade rutiner och strukturer som är homogena genom hela bolaget. Ett gemensamt ritningssystem resulterar i bättre kvalitet och bättre samarbete mellan de olika avdelningarna.
SAS Technical Services (STS) hade inte ett gemensamt ritningssystem vilket har lett till att de olika avdelningarna har utvecklat olika rutiner rörande ritningar. Önskemålet var utvecklande av nya rutiner rörande ingenjörsritningar såsom ritningsnumreringsstruktur, revisions- och prenumerationsrutiner, vilka standarder som skall följas, egna ritningsmallar och skötsel av ritningar med tillhörande dokument.
Varje önskad uppgift blev uppdelad i mindre uppgifter och analyserad. Lösningar från olika ledande ingenjörsbolag användes för jämförelse och idéer.
Alla uppgifterna samlades och organiserades i ett och samma dokument som är resultatet av detta arbete; en ritningsinstruktion.
Ritningsinstruktionen kommer efter en inlärningsfas underlätta arbetet för ingenjörerna på STS eftersom all nödvändig information nu finns på ett och samma ställe. Arbeten med entreprenörer vill också bli underlättande eftersom instruktionen kan delas ut för vägledning.
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Bausch, Francis A. « Examining One's Own : Reflexivity and Critique in STS ». Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/31361.
Texte intégralRésumé :
The principle of reflexivity, as laid out by David Bloor (in Knowledge and Social Imagery) poses serious challenges to STS - while STS analysts attempt to show the partiality of scientific claims, they simultaneously offer those analyses via authoritative pronouncements in scientific language, while claiming a scientific foundation.
This thesis questions the understanding of science as a form of inquiry distinct from other forms of inquiry, especially focusing on the elusive distinction between science and technology. The thesis analyzes Andrew Pickering's problematic attempt (in The Mangle of Practice) to dissolve the science/technology distinction through his 'Theory of Everything'/Mangle concept. Building an approach from commentaries on Pickering's work combined with resources from the STS tradition, especially from Latour and Haraway, the author proposes a new observational stance; this stance insists on the perspectival nature of all observation, and thereby claims to be reflexively robust; furthermore it maintains an agnostic attitude with regard to the science/technology distinction.Master of Science
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García, Aljaro Cristina. « Detección del gen "stx2" en muestras ambientales y evaluación de su variabilidad ». Doctoral thesis, Universitat de Barcelona, 2004. http://hdl.handle.net/10803/2392.
Texte intégralRésumé :
Las cepas de Escherichia coli productoras de toxina Shiga han emergido recientemente como patógenos humanos, provocando graves enfermedades como la colitis hemorrágica y el síndrome urémico hemolítico. Los principales factores de virulencia de estas cepas lo constituyen unas potentes citotoxinas conocidas como toxinas Shiga (codificadas por genes stx en el genoma de bacteriófagos atemperados), una proteína de membrana externa (intimina), responsable de la adhesión de la bacteria al epitelio intestinal y una enterohemolisina. La transmisión horizontal de los genes stx mediada por bacteriófagos, podría explicar la elevada diversidad de serotipos de E. coli portadores de estos genes.El objetivo de la tesis doctoral fue el análisis de la prevalencia del gen stx2 en ambientes acuáticos y la detección, el aislamiento y la caracterización de las bacterias portadoras del gen, así como el estudio de los bacteriófagos portadores del gen stx2 integrados en estas bacterias.
Se diseñó un método basado en la combinación del NMP y la PCR anidada utilizando cebadores específicos para la subunidad A del gen stx2 para el estudio de prevalencia. Se analizaron aguas residuales crudas municipales y de mataderos. El gen stx2 fue detectado en todas las muestras, observándose una relación constante entre el número estimado de cepas stx2 estimado independientemente del origen de la muestra.
Se caracterizaron 144 cepas portadoras del gen stx2 aisladas mediante el método de la hibridación colonial utilizando agar chromocult y una sonda específica para el gen stx2. Asímismo, se aislaron 72 cepas de E. coli O157 utilizando la técnica de la separación inmunomagnética, la siembra en el medio selectivo CT-SMAC y la detección inmunológica del antígeno O157. También se analizó el patrón de digestión del lipopolisacárido. Se seleccionaron un total de 65 cepas portadoras del gen stx2 y 28 cepas O157, como representantes. Todas las cepas fueron clasificadas como E. coli mediante la galería API 20E o secuenciación del 16S rDNA. Estas cepas fueron serotipadas detectándose 36 serotipos, algunos de los cuales no habían sido identificados previamente como portadores del gen stx2 . Posteriormente, se analizó la resistencia a diferentes antibióticos siendo las sulfonamidas, tetraciclina, cloramfenicol, trimetroprim y estreptomicina los antibióticos que presentaron mayor número de resistencias. Todas las cepas eran portadoras de una o dos de las variantes del gen stx2 descritas (c, d, e y g). Respecto a otros factores de virulencia se detectó el gen stx1 n el 28% y 20% de las cepas aisladas de agua residual urbana y agua residual de matadero bovino respectivamente. El gen eae fue detectado en las cepas E. coli O157:H7 mientras que el gen codificante para la enterohemolisina fue detectado en el 7%, 46% y el 11% de agua residual urbana, matadero bovino, y agua residual de origen mixto, respectivamente. El gen saa fue detectado en 5 cepas. Se detectó la producción de proteína Stx2 en algunas de las cepas aisladas, mayoritariamente aquellas de origen bovino. En el caso de la Stx1 un mayor porcentaje de cepas que expresaban el gen.
La mayoría de las cepas aisladas presentaron bacteriófagos inducibles algunos de los cuales eran portadores del gen stx2 (mayoritariamente cepas aisladas de agua residual de matadero bovino). Los bacteriófagos portadores de distintas variantes del gen stx2 presentaron variabilidad en cuanto a su capacidad de infectar a diferentes cepas huésped. Además presentaron variabilidad en los patrones RFLP y sitio de integración. Estos bacteriófagos presentaron dos morfologías diferentes: cápsides icosaédricas hexagonales con colas cortas y cápsides alargadas con colas largas.
La diversidad de bacteriófagos portadores del gen stx2 observada podría contribuir a la dispersión del gen stx2 entre las diferentes poblaciones bacterianas.
ENGLISH
Shiga toxin producing Escherichia coli have emerged recently as human pathogens. The main virulence factors are the Shiga toxins (which are bacteriophage encoded), the external membrane protein called intimin, which is responsible for the adhesion of the bacterium to the intestinal epithelium and the hemorrhagic hemolysin.
The aim of the study was to analyse the prevalence of the stx2 gene, the detection, isolation and characterization of the stx2 gene-carrying bacteria from aquatic environments and the characterization of the stx2 bacteriophages which are integrated in the genome of these bacteria.
A combination of the NMP and the nested PCR method was used to evaluate the prevalence of the stx2 gene in raw municipal sewage and animal wastewater. The stx2 gene was detected in all the samples with a constant ratio between stx2 and the bacterial indicators analysed. 144 strains were isolated by colony blot hybridisation. 72 E. Coli O157 strains were isolated using IMS, CT-SMAC and the immunological detection of the O157 antigen. These strains were biochemically characterized and a total of 65 stx2 and 28 O157 strains were chosen as representatives for further studies.
All the strains were identified as E. Colibelonging to 36 diferent serotypes. These strains antibiotics were mostly resitant to sulfonamides, tetracycline, cloramfenicol, thrimethroprim. All the strains carried one or two stx2 gene variants. The stx1 gene was detetcted in 28% and 20% of the isolated strains of urban sewage and bovine slaughterhouse. The eae gene was detected in E. ColiO157:H7, and the ehxA gene in 7%, 46% and 11% of municipal sewage, bovine slaughterhouse, and mixed slaughterhouse wastewater origin, respectively. The saa gene was detected in 5 strains. Production of Stx2 protein was detected mainly in strains from bovine origin. A greater percentage of strains expressed the stx1 gene.
Most of the isolated strains harbored stx2 bacteriophages in their genome (mainly strains from bovine slaughterhouse origin), which carried different stx2 variants, presented variability in the RFLP analysis as well as in the infection to different hosts. The diversity of stx2 bacteriophages observed could contribute to the dispersion of the gene stx2 between the different bacterial populations.
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Souza, Nayara Lopes de. « CARACTERIZAÇÃO GENÉTICA DE 12 LOCI STRs DO CROMOSSOMO X NA POPULAÇÃO BRASILEIRA ». Pontifícia Universidade Católica de Goiás, 2018. http://tede2.pucgoias.edu.br:8080/handle/tede/3984.
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Database construction with allelic and genotypic frequencies of STRs has a significant impact on the processes of human identification of different populations. Brazil already has a database of allelic and genotype frequencies of the markers of the autosomal chromosomes and markers of the Y chromosome. However, there are few studies of allelic and genotype frequencies for markers of the X chromosome. These markers have a high discrimination power and have a high rate of resolution in forensic situations, and genetic linkage analysis. The objective of this study was to estimate, in a Brazilian population, allelic and genotypic frequencies, observed in 12 STR markers of the X chromosome, aiming the consolidation of a population database with applications in genetic linkage research. For this, 1,190 genetic profiles of individuals not genetically related and submitted to genetic linkage tests from all regions of Brazil were analyzed. The samples were genotyped using the Investigator® Argus X-12 system (Qiagen, Germany). Capillary electrophoresis was performed on ABI 3500 gene analyzer. Allele frequencies were analyzed using Genetix 4.05.2 and Alerquin ® software and Hardy-Weinberg equilibrium was analyzed using GenePop 4.1.3 and Alerquin® software. Allele and genotype frequencies were obtained for the 12 STRs of the X chromosome, the 15 allele of the DXS7423 locus was the most frequent, presenting a value corresponding to 0.40 in the female sex and 0.44 in the male sex. However, several alleles in all markers presented frequencies lower than 0.01, being considered rare in the population. No Deviation of Hardy-Weinberg Equilibrium was observed in the marker set when analyzed simultaneously. The DXS10135 locus had a higher expected heterozygosity than the other loci for females, with a frequency of 0.9445. The observed heterozygosity also presented variation regarding the values found, from 0.9160 to 0.6803. Thus, the Argus X-12 system was informative in the Brazilian population and, therefore, a useful tool in forensic practice, particularly in inconclusive cases and in cases of kinship involving high complexity.
A construção de banco de dados com frequências alélicas e genotípicas de marcadores STRs tem um impacto significativo nos processos de identificação humana de diferentes populações. O Brasil já possui banco de dados de frequências alélicas e genotípicas dos marcadores dos cromossomos autossômicos e marcadores do cromossomo Y. No entanto, existem poucos estudos de frequências alélicas e genotípicas para os marcadores do cromossomo X. Estes marcadores possuem um alto poder de discriminação e apresentam alta taxa de resolutividade em situações forenses, e análises de vínculo genético. O objetivo deste estudo foi estimar, em uma amostra populacional brasileira, frequências alélicas e genotípicas, observadas em 12 marcadores STR do cromossomo X visando a consolidação de um banco de dados populacional com aplicações em investigação de vínculo genético. Para isso, foram analisados 1.190 perfis genéticos de indivíduos não relacionados geneticamente e submetidos a testes de investigações de vínculo genético, provenientes de todas as regiões do Brasil. As amostras foram genotipadas utilizando o sistema Investigator® Argus X-12 (Qiagen, Germany). A eletroforese capilar foi realizada no analisador genético ABI 3500. As frequências alélicas e genotípicas foram analisadas com auxílio do software Genetix 4.05.2 e Alerquin®, o equilíbro de Hardy-Weinberg foi analisado através do software GenePop 4.1.3. As frequências alélicas e genotípicas foram obtidas para os 12 marcadores STRs do cromossomo X, o alelo 15 do locus DXS7423 foi o mais frequente, apresentando valor correspondente a 0,40 no sexo feminino e 0,44 no sexo masculino. No entanto, diversos alelos em todos os marcadores apresentaram frequências inferiores a 0,01, sendo considerados raros na população. Não foi observado desvio do Equilíbrio de Hardy- Weinberg no conjunto de marcadores quando analisados simultaneamente. O locus DXS10135 apresentou uma heterozigosidade esperada maior em relação aos outros loci para os indivíduos do sexo feminino, com frequência 0,9445. A heterozigosidade observada também apresentou variação quanto aos valores encontrados, de 0,9160 a 0,6803. Sendo assim, o sistema Argus X-12 apresentou-se informativo na população brasileira, sendo, portanto, uma ferramenta útil na prática forense, particularmente em casos inconclusivos e em casos de parentesco envolvendo alta complexidade.
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Robison-Chadwell, Amanda. « U.S. Young Adults STDs, Risk Perception, Risk Behaviors, and Health Information Seeking ». ScholarWorks, 2017. https://scholarworks.waldenu.edu/dissertations/4096.
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Sexually transmitted diseases (STD) are preventable conditions for which treatment failure (specifically in gonorrhea) is becoming problematic. U.S. young adults (20-29 years) have high rates of STD incidence and prevention of these diseases, but reaching them to provide primary prevention educations is challenging due to low perceived susceptibility to infection and lack of knowledge about how young adults seek health information. The purpose of this quantitative survey study was to assess the association between perceived susceptibility to STDs, sexual risk behavior, and the acquisition of health information as it pertains to sexual health topics in young adults. The Health Belief Model (HBM) and the Theory of Planned Behavior (TPB) were used in combination as the theoretical foundation of this study. Data collection was done using an adapted version of the Health Information National Trends Survey (HINTS), the Condom Use Self Efficacy Scale (CUSES), and an adapted version of the Marin County (California) Health Department's Sexual Risk Survey. There were 128 eligible participants and analysis of the data showed that the internet was the primary source of both general health information (87.5%) and STD specific health information (75.8%). A multiple regression analysis showed that there was no statistically significant correlation between perceived susceptibility and health information seeking or sexual risk (p > .05).
This can aid in positive social change by prompting additional research on the subject of STD prevention in young adults through the design and dissemination of tools for education that may reduce the rate of STDs or other health ailments.
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Hall, Natasha. « Provider-Initiated Condom Education, HIV, and STDs Among Older African American Women ». ScholarWorks, 2015. https://scholarworks.waldenu.edu/dissertations/1646.
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Older African American (AA) women are at increased risk for HIV and STDs. The purpose of this quantitative study was to examine the influence of provider-initiated condom use education on condom use among unmarried, heterosexually active AA women aged 50 and over using the constructs of self-efficacy and attitudes of the health belief theoretical model. The relationships between provider education on condom use, condom use self-efficacy, condom use attitudes, and actual condom use were tested individually, and provider education on actual condom use was tested after controlling for condom use self-efficacy and attitudes among 95 study participants recruited primarily from Raleigh-Durham, NC. A 2-tailed sample t test or analysis of covariance was used for analysis. Provider education on condom usage failed to show a benefit with regard to condom usage, condom use self-efficacy, and attitudes toward condom usage. Additionally, women who received provider education on condom use were less likely to use condoms. Possibly these women had a low perception of risk and vulnerability to HIV and STDs, which correlated with lower condom use. The counter intuitive findings could also be related to another variable that was not tested and should spur more research. Results could be used to contribute to the design of an intervention model that specifically addresses the sexual behaviors of older AA women. Results of this study, combined with previous research, can help emphasize the need for improved patient-provider communication so that provider communication produces a more positive outcome and helps limit the spread of HIV and STDs, a limitation that would benefit individuals, whole communities, and the nation.
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Hughes, Megan Elizabeth. « Use of Simulation to Investigate Muscle Forces and Contributions to the STS transfer and Sensitivity to Muscle Weakness during the STS Transfer ». The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1543530282616967.
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Fogg, Paul C. M. « Stx-Phage Integration and Multiple Lysogeny in Escherichia coli ». Thesis, University of Liverpool, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491342.
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The characteristic virulence factor of shigatoxigenic E. coli strains (STEC) is the expression of Shiga-toxin encoded in the late gene region of temperate lambdoid phages. The use of differentially labelled isogenic recombinant Stx phage (cD24B) had demonstrated the production of true double lysogens in E. coli, contrary to the lambda immunity model, however, the insertion sites and underlying mechanisms had not been determined. Here, the bacteriophage <1>24B integrase gene and the preferred site of insertion in the E. coli genome have been identified. The integrase encoded by <1>24B differs significantly from the integrases of all other previously characterised phages, and the insertion site shares 24 bp of complimentary sequence with the phage aUP site. Furthermore, an additional 3 integration sites in the E. coli genome were elucidated, each with a decreased level of ide'ntity with the aUP site. Triple lysogens could be produced by means of isogenic phage in which the stx gene was interrupted with kanamycin, chloramphenicol and spectinomycin resistance genes as reporters. There were seven possible sites of integration identified, two of which lay within predicted essential genes in the E. coli genome, and thus could not be occupied, and integration at another site was never observed. The preferred integration site described above was close to an integrase gene on the E. coli chromosome but it was demonstrated unequivocally that this host integrase was not responsible for the multiple integration events. The complete partially annotated genome sequence of <1>24B revealed the presence of a gene homologous to the putative antirepressor encoding genes ofVT2-Sa and Lahul and similarity to the well-characterised phage P22 ant gene. Antirepressors bind to the lambdoid phage cI repressor responsible for superinfection immunity and it is therefore possible that the presence of an ant gene on
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Wickramanayake, Ama Manjarie. « WRFM Process Improvement ». Thesis, University of Canterbury. Engineering Management, 2014. http://hdl.handle.net/10092/8953.
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The intent of this Project was to identify areas of improvement in Shell Todd Oil Services (STOS) Well, Reservoir and Facility Management (WRFM) practices, in order to meet full compliance with Shell global WRFM Standards by their next annual review in Q4 2014. A gap analysis was carried out to identify where improvement efforts must be focussed and measures to support optimisation, streamlining and alignment of processes have been recommended.
The Shell Blade 27 – Well, Reservoir and Facility Management Guideline was used to obtain insight and understanding of the WRFM process and requirements. The STOS WRM Management Manual, WRFM Plans and Health-check outputs were used as supplementary documentation for the gap analysis. The Shell WRFM minimum requirements were used as the established benchmark against which STOS practices were measured using the asset assessment tool. Interviews were carried out to further highlight complexities and constraints at STOS to meet Shell criteria.
The findings in this report provide evidence of issues that should be addressed for the continuous improvement of WRFM at STOS. These have been provided for the consideration of Shell Todd Oil Services Limited WRFM Steering Committee Chair.
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Zhao, Hui. « Discrimination of High Risk and Low Risk Populations for the Treatment of STDs ». Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/math_theses/104.
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It is an important step in clinical practice to discriminate real diseased patients from healthy persons. It would be great to get such discrimination from some common information like personal information, life style, and the contact with diseased patient. In this study, a score is calculated for each patient based on a survey through generalized linear model, and then the diseased status is decided according to previous sexually transmitted diseases (STDs) records. This study will facilitate clinics in grouping patients into real diseased or healthy, which in turn will affect the method clinics take to screen patients: complete screening for possible diseased patient and some common screening for potentially healthy persons.
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Schneider, Glenn, Carol A. Grady, Christopher C. Stark, Andras Gaspar, Joseph Carson, John H. Debes, Thomas Henning et al. « DEEP HST /STIS VISIBLE-LIGHT IMAGING OF DEBRIS SYSTEMS AROUND SOLAR ANALOG HOSTS ». IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/621501.
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We present new Hubble Space Telescope observations of three a priori known starlight-scattering circumstellar debris systems (CDSs) viewed at intermediate inclinations around nearby close-solar analog stars: HD 207129, HD 202628, and HD 202917. Each of these CDSs possesses ring-like components that are more massive analogs of our solar system's Edgeworth-Kuiper Belt. These systems were chosen for follow-up observations to provide imaging with higher fidelity and better sensitivity for the sparse sample of solar-analog CDSs that range over two decades in systemic ages, with HD 202628 and HD 207129 (both similar to 2.3 Gyr) currently the oldest CDSs imaged in visible or near-IR light. These deep (10-14 ks) observations, made with six-roll point-spread-function template visible-light coronagraphy. using the Space Telescope Imaging Spectrograph, were designed to better reveal their angularly large debris rings of diffuse/low surface brightness, and for all targets probe their exo-ring environments for starlight-scattering materials that present observational challenges for current ground-based facilities and instruments. Contemporaneously also observing with a narrower occulter position, these observations additionally probe the CDS endo-ring environments that are seen to be relatively devoid of scatterers. We discuss the morphological, geometrical, and photometric properties of these CDSs also in the context of other CDSs hosted by FGK stars that we have previously imaged as a homogeneously observed ensemble. From this combined sample we report a general decay in quiescent-disk F-disk/F-star optical brightness similar to t(-0.8), similar to what is seen at thermal IR wavelengths, and CDSs with a significant diversity in scattering phase asymmetries, and spatial distributions of their starlight-scattering grains.
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Feng, Yuji. « Prevalence of HIV/STDs among MSM in Chengdu, China and associated risk factors ». Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1562153441&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
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