Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-07-04T17:46:23Z No. of bitstreams: 1 TES_STEPHANIE_WAGNER_GALLO_PARCIAL.pdf: 790698 bytes, checksum: 760c735fb69bbd136bd69c8c9ddfb82d (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-07-04T17:46:32Z (GMT) No. of bitstreams: 1 TES_STEPHANIE_WAGNER_GALLO_PARCIAL.pdf: 790698 bytes, checksum: 760c735fb69bbd136bd69c8c9ddfb82d (MD5) / Made available in DSpace on 2017-07-04T17:46:40Z (GMT). No. of bitstreams: 1 TES_STEPHANIE_WAGNER_GALLO_PARCIAL.pdf: 790698 bytes, checksum: 760c735fb69bbd136bd69c8c9ddfb82d (MD5) Previous issue date: 2017-03-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Funda??o de Amparo ? Pesquisa do Estado do Rio Grande do Sul (FAPERGS) / Acinetobacter calcoaceticus-baumannii (ACB) complex comprises opportunistic and emerging pathogens that are responsible for several diseases, mainly affecting immunocompromised patients and those hospitalized in intensive care units. Therapeutic options for ACB infections are restricted, since these microorganisms are often resistant to most antimicrobials. In addition, these bacteria may also form persister cells, which constitute a small population of susceptible cells able to survive lethal concentrations of bactericidal antimicrobials and other stressors. This phenotype is associated with failure in antimicrobial therapy, especially in chronic and recurrent infections. Therefore, the aim of this study was to evaluate the presence of persister cells from ACB complex isolates exposed to meropenem and/or polymyxin B, in biofilm and planktonic cells, as well as to analyze these cells regarding their morphology and identify expression patterns of proteins possibly involved in the formation and maintenance of persistence. For this, 20 clinical isolates were characterized for the ability to form biofilm on polystyrene surface, and for meropenem and polymyxin B susceptibility, by the assessment of Minimum Inhibitory Concentration (MIC). All isolates were exposed to meropenem at different concentrations above the MIC, while five isolates were exposed to polymyxin B for the assessment of the persisters presence. For all experiments, in order to estimate the fraction of remaining cells, aliquots were removed at determined time points, followed by serial decimal dilutions and drop plating technique on nutrient agar. All isolates presented persisters at different proportions, in both culture conditions when exposed to meropenem or polymyxin B after 48 h. The higher fractions were verified in biofilm for both antimicrobials in comparison with planktonic cultures. Meropenem concentrations did not influence persisters levels. However, after polymyxin B exposure, persister cells fractions were dependent on the concentration employed. After 24 h polymyxin B exposure, a growth resumption of surviving cells was observed. These cells were again evaluated for susceptibility to this antimicrobial, remaining susceptible with MIC of 1 ?g/ mL. Moreover, integrity of polymyxin B in the supernatant of the cultures was verified by chromatographic assay, demonstrating that polymyxin B is not significantly degraded after 48 h exposure. On the other hand, when meropenem and polymyxin B were associated at different concentrations, no resumption of cell growth was observed, as well as this combination was able to eradicate persister cells from A. baumannii (Acb-1) cultured in late exponential phase. Furthermore, Nano-Liquid Chromatography Coupled to Tandem Mass Spectrometry was employed for the identification and relative quantification of proteins possibly associated with persistence in A. baumannii, after exposure to meropenem. Different patterns of expression were identified between persister cells present in planktonic and biofilm cultures, suggesting that persistence may be regulated by different mechanisms. Proteins involved in the cell division and DNA replication were overexpressed in planktonic persisters, in agreement with the electron scanning microscopy images that presented dividing cells in this culture condition. Overexpression of glucose dehydrogenase (GDH), NADH dehydrogenase 1 (NDH-1), succinate dehydrogenase and ATP synthase indicates the electron transfer from the GDH-catalyzed reaction to the electron transport chain as a possible energy source for persisters, supporting the presence of cell division observed in planktonic culture. Conversely, proteins involved in amino acid metabolism, as well as major elongation factors were underexpressed in Acb-1 persister cells, suggesting that protein synthesis is reduced, even though many proteins were overproduced. Increased expression of several membrane-related proteins has also been observed, indicating possible changes in its composition and function, although proteins related to lipid metabolism were underexpressed. Overall, proteomic analysis of the persister cells showed that these cells could be physiologically distinct when cultured under different conditions, as well as overtime in the same condition. Therefore, considering the different behaviors of Acb-1 when exposed alone to meropenem or polymyxin B, as well as when exposed to these drugs in combination, it was concluded that each antimicrobial might act as a different stressor, possibly leading and/or selecting distinct tolerance mechanisms among persisters, which enabled their eradication when the drugs were combined. / Os pat?genos pertencentes ao complexo Acinetobacter calcoaceticus-baumannii (ACB) s?o considerados oportunistas e emergentes, respons?veis por ocasionar diversas enfermidades, acometendo principalmente pacientes imunocomprometidos e internados em unidades de tratamento intensivo. As op??es terap?uticas para o tratamento de infec??es ocasionadas por estes pat?genos s?o restritas, uma vez que estes apresentam frequentemente resist?ncia ? maioria dos antimicrobianos. Al?m disso, essas bact?rias podem ainda formar c?lulas persisters, que constituem uma pequena popula??o de c?lulas suscet?veis capazes de tolerar concentra??es letais de antimicrobianos bactericidas e outros agentes estressores. Este fen?tipo est? associado a falhas na terapia antimicrobiana, especialmente nas infec??es cr?nicas e recorrentes. Desta forma, o objetivo deste trabalho foi avaliar a presen?a de c?lulas persisters formadas por isolados do complexo ACB frente ? exposi??o ao meropenem e/ou ? polimixina B, na condi??o de biofilme e em cultivo planct?nico, assim como analisar estas c?lulas morfologicamente e identificar padr?es de express?o de prote?nas que pudessem estar envolvidos na forma??o e manuten??o da persist?ncia. Para tanto, 20 isolados cl?nicos foram caracterizados quanto ? capacidade em formar biofilme em superf?cie de poliestireno, e ? suscetibilidade ao meropenem e ? polimixina B, que foi avaliada por meio da determina??o da Concentra??o Inibit?ria M?nima (CIM) a estes f?rmacos. Todos os isolados foram submetidos ? exposi??o ao meropenem em diferentes concentra??es acima da CIM, enquanto que cinco foram expostos ? polimixina B para a avalia??o da presen?a de c?lulas persisters. Para todos os experimentos, a fim de estimar a fra??o de c?lulas remanescentes, al?quotas foram removidas em tempos determinados, efetuando-se dilui??es decimais seriadas e semeadura pela t?cnica da gota em ?gar nutriente. C?lulas persisters, em diferentes fra??es, foram encontradas nos cultivos de todos os isolados, tanto em biofilmes como na condi??o planct?nica, ap?s a exposi??o por 48 h ao meropenem e ? polimixina B, sendo as fra??es mais elevadas encontradas na condi??o de biofilme para ambos os antimicrobianos. As diferentes concentra??es de meropenem avaliadas n?o influenciaram os n?veis de c?lulas persisters; entretanto, frente ? exposi??o ? polimixina B, a fra??o de c?lulas mostrou-se dependente da concentra??o empregada. Ap?s exposi??o ? polimixina B por 24 h, foi observada retomada de crescimento das c?lulas sobreviventes, que foram avaliadas novamente quanto ? suscetibilidade a este antimicrobiano, mantendo-se suscet?veis com CIM de 1 ?g/mL, bem como foi verificada a integridade do antimicrobiano no sobrenadante destes cultivos por ensaios cromatogr?ficos, demonstrando que o mesmo n?o sofre degrada??o ap?s 48 h de exposi??o. Entretanto, quando se associou meropenem ? polimixina B em diferentes concentra??es, al?m de n?o ter sido observada a retomada de crescimento das c?lulas remanescentes, ocorreu a erradica??o das c?lulas persisters de um isolado de A. baumannii (Acb-1) cultivado em fase exponencial tardia. Al?m disso, a t?cnica de Nano-Cromatografia L?quida acoplada ? Espectrometria de Massas em Tandem foi empregada para a identifica??o e quantifica??o relativa de prote?nas possivelmente associadas ? persist?ncia em A. baumannii, ap?s a exposi??o ao meropenem. Diferentes padr?es de express?o foram identificados entre as c?lulas persisters presentes em cultivo planct?nico e em biofilme, sugerindo que a regula??o da persist?ncia possa ser realizada por mecanismos diferentes. Observou-se express?o aumentada de prote?nas envolvidas nos processos de divis?o celular e replica??o de DNA, especialmente no cultivo planct?nico, em concord?ncia com a presen?a de divis?o celular observada nas imagens obtidas a partir da microscopia eletr?nica de varredura nesta condi??o de cultivo. O aumento de express?o da glicose desidrogenase (GDH), NADH desidrogenase (NDH-1), succinato desidrogenase e ATP sintase indicam a transfer?ncia de el?trons a partir da rea??o catalisada por GDH para a cadeia de transporte de el?trons como uma poss?vel fonte de energ?tica para as persisters, corroborando a observa??o da presen?a de divis?o celular observada no cultivo planct?nico. Em contraste, prote?nas envolvidas no metabolismo de amino?cidos, bem como os principais fatores de elonga??o apresentaram express?o diminu?da em c?lulas persisters de Acb-1, sugerindo que a s?ntese proteica esteja reduzida, mesmo que muitas prote?nas tenham sido identificadas com express?o aumentada. Muitas prote?nas relacionadas ? membrana apresentaram a sua express?o aumentada, indicando poss?veis altera??es em sua composi??o e fun??o, embora prote?nas relacionadas ao metabolismo de lip?deos tenham apresentado express?o diminu?da. A an?lise prote?mica das c?lulas persisters, sobretudo, mostrou que estas c?lulas podem ser fisiologicamente distintas quando cultivadas em condi??es diferentes, bem como ao longo do tempo em uma mesma condi??o. Desta forma, considerando os distintos comportamentos do Acb-1 quando exposto isoladamente ao meropenem ou ? polimixina B, bem como quando exposto a estes f?rmacos ao mesmo tempo, pode-se concluir que cada antimicrobiano pode ter atuado como um diferente estressor, possivelmente, levando a e/ou selecionando mecanismos de toler?ncia diferentes entre as persisters, o que possibilitou a sua erradica??o quando os f?rmacos foram combinados.

abstract: Using a sample of 931 undergraduate students, the current study examined the influential factors on undergraduate students' academic performance, satisfaction, and intentions to persist in their enrolled major. Specifically, the current study investigated the salience of interest-major match in predicting academic success. Interest-major match has been found to be one of the most influential determinants of academic and occupational success. However, support for this relationship has been equivocal and modest at best. The present study was designed to improve upon the current understanding of this relation by examining the moderating effect of gender and employing a longitudinal design to investigate the reciprocal relation between interest-major match and academic outcomes. Correlational results suggested that women reported greater interest-major match and results of the path analyses demonstrated a moderating effect of gender. Although a reciprocal relation was not supported, the findings indicated that a student’s level of academic satisfaction may influence the degree of fit between his or her interest and academic major. The results also highlight the tendency for students further along in their academic tenure to persist to graduation despite poor fit. Implications for educators and administrators are discussed. / Dissertation/Thesis / Doctoral Dissertation Counseling Psychology 2016

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-22T15:02:52Z No. of bitstreams: 1 JeanGuerethesFernandesGuedes_DISSERT.pdf: 3398698 bytes, checksum: 6e847e280c1fe33f04641aa4bc1758db (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-26T23:20:34Z (GMT) No. of bitstreams: 1 JeanGuerethesFernandesGuedes_DISSERT.pdf: 3398698 bytes, checksum: 6e847e280c1fe33f04641aa4bc1758db (MD5) / Made available in DSpace on 2016-07-26T23:20:34Z (GMT). No. of bitstreams: 1 JeanGuerethesFernandesGuedes_DISSERT.pdf: 3398698 bytes, checksum: 6e847e280c1fe33f04641aa4bc1758db (MD5) Previous issue date: 2015-08-28 / Diante da crescente demanda pela cria??o de aplicativos m?veis, impulsionada pelo usocada vez mais frequente de smartphones e tablets, cresceu na sociedade a necessidade poracesso a dados remotos de forma integral na utiliza??o do aplicativo m?vel em ambientessem conectividade, em que n?o h? disponibiliza??o de acesso ? rede em todos os momentos.Diante dessa realidade, esse trabalho teve como objetivo o desenvolvimento de uma solu??oatrav?s de um framework, que apresente como principais fun??es o provimento de ummecanismo de persist?ncia, replica??o e sincroniza??o dos dados, contemplando a cria??o,remo??o, atualiza??o e visualiza??o dos dados persistidos ou requisitados, mesmo estandoo dispositivo m?vel sem conectividade com a rede. Do ponto de vista das pr?ticas deprograma??o e arquitetura, isso reflete em definir estrat?gias para persist?ncia de dadoslocal, replica??o e sincroniza??o de dados. Atrav?s de um estudo controlado foi poss?velvalidar a solu??o proposta, sendo constatado ganhos como a redu??o na quantidade delinhas de c?digo e de quantidade de tempo necess?rios para realizar o desenvolvimento deum aplicativo sem que houvesse aumento significativo para a realiza??o das opera??es. / Given the growing demand for the development of mobile applications, driven by use increasingly common in smartphones and tablets grew in society the need for remote data access in full in the use of mobile application without connectivity environments where there is no provision network access at all times. Given this reality, this work proposes a framework that present main functions are the provision of a persistence mechanism, replication and data synchronization, contemplating the creation, deletion, update and display persisted or requested data, even though the mobile device without connectivity with the network. From the point of view of the architecture and programming practices, it reflected in defining strategies for the main functions of the framework are met. Through a controlled study was to validate the solution proposal, being found as the gains in reducing the number of lines code and the amount of time required to perform the development of an application without there being significant increase for the operations.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-06-05T18:15:26Z No. of bitstreams: 1 CeciliaMariaMedeirosDantasDeMelo_DISSERT.pdf: 1373911 bytes, checksum: 0b5059e6a28df228fafad46f8f5cc835 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-06-12T20:02:22Z (GMT) No. of bitstreams: 1 CeciliaMariaMedeirosDantasDeMelo_DISSERT.pdf: 1373911 bytes, checksum: 0b5059e6a28df228fafad46f8f5cc835 (MD5) / Made available in DSpace on 2017-06-12T20:02:22Z (GMT). No. of bitstreams: 1 CeciliaMariaMedeirosDantasDeMelo_DISSERT.pdf: 1373911 bytes, checksum: 0b5059e6a28df228fafad46f8f5cc835 (MD5) Previous issue date: 2017-03-10 / Os estudos sobre remunera??o de executivos t?m sido foco de bastante discuss?o no meio acad?mico e no mercado. Esta pesquisa busca analisar se a remunera??o dos executivos exerce influ?ncia na persist?ncia do desempenho das empresas listadas na BM&FBOVESPA. Para atingir este objetivo, foi utilizado um modelo econom?trico com as vari?veis ? lucro operacional, remunera??o fixa, b?nus, participa??o nos lucros, pagamento baseado em a??es, tamanho, alavancagem e grau de responsabilidade social, para uma amostra de cento e quatro empresas abertas, no per?odo de 2011 a 2015, cujas informa??es est?o dispon?veis na base de dados da Bloomberg. Utilizou-se, como ferramenta estat?stica, uma abordagem de painel din?mico por estima??o pelo M?todo dos Momentos Generalizados de Sistema (GMM-SYS), de Arellano e Bover (1995) e Blundell e Bond (1998). Os resultados mostram que apenas as empresas de controle governamental n?o apresentaram resultados persistentes. Quanto ? remunera??o, observou-se que a parcela fixa contribui para o aumento da persist?ncia no desempenho das companhias de controle institucional, familiar e difuso. Al?m disso, verificou-se, em todos os tipos de controle, a n?o signific?ncia do pagamento de b?nus, apesar de ter apresentado coeficientes relevantes. Por outro lado, a participa??o nos lucros apresentou uma rela??o positiva com o lucro operacional no ano anterior nas companhias de controle governamental. J? o pagamento baseado em a??es influencia na gera??o de lucros mais persistentes apenas quando o controle ? do tipo difuso, divergindo dos achados de Baber, Kang e Kumar (1998) e Ashley e Yang (2004), em que n?o foi observada signific?ncia de tal vari?vel. Constatou-se, ainda, que vari?veis como tamanho e alavancagem contribuem para elevar a persist?ncia dos lucros, enquanto a responsabilidade social contribui para a sua redu??o. / Studies on business executives? compensation have been the focus of much discussion in academia and in the market. This research seeks to analyze whether executive compensation influences the performance persistence of the companies listed on BM&FBOVESPA. To achieve this objective, an econometric model was used with the variables - operating profit, fixed compensation, bonus, profit sharing, share-based payment, size, leverage and social responsibility level - for a sample of one hundred and four open companies, in the period from 2011 to 2015, whose information are available in the Bloomberg database. As a statistical tool, a dynamic panel approach was used by Arellano and Bover (1995) and Blundell and Bond (1998) to estimate the system Generalized Moments of Time (GMM-SYS) method. The results show that only the governmental control companies did not present persistent results. Regarding the compensation, it was observed that the fixed compensation contributes to increase the performance persistence on institutional, family and diffuse controlled companies. In addition, it was found, in all types of control, the non-significance of the payment of bonuses, despite the relevant coefficients. On the other hand, profit sharing had a positive outcome with operating profit in the previous year in government-owned companies. The stock-based payment influences the generation profit in a more persistent way only when the control is diffuse, differing from the findings of Baber, Kang and Kumar (1998) and Ashley and Yang (2004), in which there was no significant variable change. It was also observed that variables such as size and leverage contributes to increase the persistence of profits, while social responsibility contributes to their reduction.

No description available.

Made available in DSpace on 2015-04-14T13:53:32Z (GMT). No. of bitstreams: 1 423347.pdf: 826079 bytes, checksum: 27767fb50abea565e985683b95754e83 (MD5) Previous issue date: 2010-03-18 / V?rias evid?ncias sugerem que o sistema dopamin?rgico cerebral participa do processamento mnem?nico. Contudo, o conhecimento sobre a plena contribui??o deste sistema, particularmente na regi?o hipocampal, nos processos de consolida??o e persist?ncia ainda precisam ser mais detalhados. O objetivo do presente trabalho foi avaliar a participa??o do sistema dopamin?rgico hipocampal na consolida??o e persist?ncia de mem?ria espacial atrav?s da utiliza??o do paradigma de labirinto aqu?tico de Morris (LAM). Animais com implanta??o bilateral de c?nulas na regi?o CA1 do hipocampo dorsal foram treinados durante 5 dias na vers?o espacial do Labirinto Aqu?tico de Morris (LAM). Os animais receberam a infus?o de SCH23390 ou SKF38393 (40 nmol/lado) ou ve?culo (VEH) imediatamente ou 3 horas ap?s a ultima sess?o de treino. Os resultados mostram que a infus?o de SCH23390, antagonista dopamin?rgico D1-D5, na regi?o CA1 do hipocampo dorsal de ratos imediatamente, mas n?o 3 horas, ap?s o treino na vers?o espacial do LAM prejudica a consolida??o da mem?ria para esta tarefa. Al?m disso, foi mostrado que a infus?o de SKF38393, agonista D1-D5, na regi?o CA1 do hipocampo dorsal imediatamente ap?s o treino em uma vers?o espacial de aprendizado do LAM, embora n?o melhore a consolida??o da mem?ria para esta tarefa, promove a persist?ncia do tra?o mnem?nico adquirido ao longo dos dias. Juntos, esses resultados apontam para a participa??o do sistema dopamin?rgico hipocampal na consolida??o de mem?rias espaciais bem como para uma potencial modula??o positiva na persist?ncia do tra?o mnem?nico armazenado.

Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T18:34:28Z No. of bitstreams: 1 DIS_BRUNA_KERN_DONAMORE_PARCIAL.pdf: 256997 bytes, checksum: a87e4fb183ebf7c784b824c77b71092c (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T18:34:34Z (GMT) No. of bitstreams: 1 DIS_BRUNA_KERN_DONAMORE_PARCIAL.pdf: 256997 bytes, checksum: a87e4fb183ebf7c784b824c77b71092c (MD5) / Made available in DSpace on 2017-06-30T18:34:43Z (GMT). No. of bitstreams: 1 DIS_BRUNA_KERN_DONAMORE_PARCIAL.pdf: 256997 bytes, checksum: a87e4fb183ebf7c784b824c77b71092c (MD5) Previous issue date: 2016-03-31 / Acinetobacter calcoaceticus-baumannii complex opportunistic human pathogens are responsible for several diseases affecting specially intensive care units and immunocompromised patients. These bacteria may also present the persistence phenotype, where a small population of susceptible bacteria survives after a high antimicrobial concentration treatment ? which the fraction of surviving cells may be affected by environmental conditions present in the medium. Thus, the aim of this study was to evaluate the influence of oxygen availability and galactose, sodium citrate and sheep blood presence in the formation of these cells upon meropenem and tobramycin exposure. For this, 10 clinical isolates, sent by the Clinical Pathology Laboratory of S?o Lucas Hospital, had their susceptibility characterized regarding the minimum inhibitory concentration (MIC) to tobramycin and meropenem. The influence of different environmental conditions was analyzed by exposing late exponential-phase cultures to meropenem and tobramycin for 48 h in the presence of sodium citrate, galactose and sheep blood; or in aerated or static condition. For all evaluations, aliquots were removed at determined time points, followed by serial decimal dilutions and drop plating technique on nutrient agar, to estimate the fraction of surviving cells. Aerated condition promoted a reduction of persister cells fraction ? independent of antimicrobial used ?, and, in addition, concentrations of tobramycin higher than 10X MIC provided even lower levels of these cells after 48 h of treatment. Regarding the presence of different sources of nutrients, it was observed that sodium citrate presence in 48 h of meropenem treatment promoted lower fraction of surviving cells when compared to this same antibiotic associated with galactose; whereas tobramycin exposure in the presence of galactose provided a reduced formation of persister cells in the first 6 h of treatment. Sheep blood, however, did not affect the fraction of surviving cells after 48 h of treatment, independently of the antimicrobial used. A remarkable heterogeneity in the behavior of all 10 isolates used in the study was present, regardless the conditions that have been exposed. Thus, it is possible that the conditions imposed in the experiments have influenced in the formation of persister cells by enhanced production of reactive oxygen species, and through the availability of more targets for antibiotic action by the bacterial growth stimulation. / Os pat?genos oportunistas do complexo Acinetobacter calcoaceticus-baumannii s?o respons?veis por diversas enfermidades, acometendo principalmente pacientes de unidades de tratamento intensivo e imunocomprometidos. Estas bact?rias podem ainda apresentar o fen?tipo de persist?ncia, onde uma pequena popula??o de bact?rias suscet?veis sobrevive ap?s o tratamento com elevadas concentra??es de antimicrobianos - podendo essa fra??o de c?lulas sobreviventes ser afetada pelas condi??es ambientais presentes no meio. Desta forma, o objetivo deste trabalho foi avaliar a influ?ncia da disponibilidade de oxig?nio e da presen?a de galactose, citrato de s?dio e sangue de carneiro na forma??o destas c?lulas frente ? exposi??o ao meropenem e ? tobramicina. Para isto, 10 isolados cl?nicos, cedidos pelo Laborat?rio de Patologia Cl?nica do Hospital S?o Lucas da PUCRS, tiveram sua suscetibilidade caracterizada quanto ? concentra??o inibit?ria m?nima (CIM) de tobramicina e de meropenem. A influ?ncia das diferentes condi??es ambientais foi analisada ao expor culturas de fase exponencial tardia ao meropenem e ? tobramicina por 48 h na presen?a de citrato de s?dio, galactose ou sangue de carneiro; ou em uma condi??o aerada ou est?tica. Para todas as observa??es, al?quotas foram removidas em tempos determinados, seguidas de dilui??es decimais seriadas e semeadura pela t?cnica da gota em ?gar nutriente, para estimar a fra??o de c?lulas sobreviventes. A condi??o aerada promoveu uma diminui??o na fra??o de c?lulas persisters - independente do antimicrobiano utilizado -, e tamb?m verificarmos que concentra??es superiores a 10X a CIM de tobramicina proporcionaram n?veis ainda menores destas c?lulas ap?s 48 h de tratamento. Quanto ? presen?a de diferentes fontes de nutrientes, foi observado que a presen?a de citrato de s?dio no tratamento de 48 h com meropenem proporcionou uma menor fra??o de c?lulas sobreviventes comparado a quando este mesmo antimicrobiano estava associado ? galactose; enquanto a exposi??o ? tobramicina na presen?a de galactose promoveu uma menor forma??o de c?lulas persisters nas primeiras 6 h de tratamento. O sangue de carneiro, entretanto, n?o afetou a fra??o de c?lulas sobreviventes ap?s 48 h de tratamento, independente do antimicrobiano utilizado. P?de-se ainda constatar uma not?vel heterogeneidade no comportamento de todos os 10 isolados utilizados no estudo, independente das condi??es as quais foram expostos. Desta forma, ? poss?vel que as condi??es avaliadas nos experimentos tenham influenciado a forma??o c?lulas persisters atrav?s da maior produ??o de esp?cies reativas de oxig?nio, e por disponibilizar mais alvos para a a??o dos antimicrobianos ao estimular o crescimento bacteriano.

The purpose of this study was to develop and evaluate engineering self-efficacy measures for undergraduate students (N = 321) and to examine whether students' engineering self-efficacy differed by gender, year level, and major. The relationships between engineering self-efficacy and academic achievement and intent to persist in engineering were also investigated. Data from engineering students from two southeastern universities were collected in spring 2013. Exploratory factor analyses resulted in a unidimensional general engineering self-efficacy scale and a three-factor (i.e., research skills, tinkering skills, and engineering design) engineering skills self-efficacy scale. Multivariate analyses of variance revealed that self-efficacy did not differ by gender or year level. Students in different engineering sub disciplines reported different levels of tinkering self-efficacy. Multiple regression analysis showed that engineering self-efficacy measures predicted academic achievement outcomes but not intent to persist in engineering. Engineering self-efficacy significantly contributed to the prediction of achievement after controlling for prior achievement. Research funded by the National Science Foundation, EEC Award No.1240328.

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Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-07-03T15:03:25Z No. of bitstreams: 1 TES_TACIANO_DRECKMANN_PEREZ_COMPLETO.pdf: 1779781 bytes, checksum: 2111ccea963be0eea76bdbb7d24321d9 (MD5) / Made available in DSpace on 2017-07-03T15:03:25Z (GMT). No. of bitstreams: 1 TES_TACIANO_DRECKMANN_PEREZ_COMPLETO.pdf: 1779781 bytes, checksum: 2111ccea963be0eea76bdbb7d24321d9 (MD5) Previous issue date: 2017-05-03 / Sistemas computacionais da atualidade tradicionalmente separam mem?ria e armazenamento. Linguagens de programa??o tipicamente refletem essa distin??o usando diferentes representa??es para dados em mem?ria (ex. estruturas de dados, objetos) e armazenamento (ex. arquivos, bancos de dados). A movimenta??o de dados entre esses dois n?veis e representa??es, bidirecionalmente, compromete tanto a efici?ncia do programador quanto de execu??o dos programas. Tecnologias recentes de memoria n?o-vol?til, tais como mem?ria de transi??o de fase, resistiva e magnetoresistiva, possibilitam combinar mem?ria principal e armazenamento em uma ?nica entidade de mem?ria persistente, abrindo caminho para abstra??es mais eficientes para lidar com persist?ncia de dados. Essa tese de doutorado introduz uma abordagem de projeto para o ambiente de execu??o de linguagens com ger?ncia autom?tica de mem?ria, baseado numa combina??o original de persist?ncia ortogonal, programa??o para mem?ria persistente, persist?ncia por alcance, e transa??es com atomicidade em caso de falha. Esta abordagem pode melhorar significativamente a produtividade do programador e a efici?ncia de execu??o dos programas, uma vez que estruturas de dados em mem?ria passam a ser persistentes de forma transparente, sem a necessidade de programar explicitamente o armazenamento, e removendo a necessidade de cruzar fronteiras sem?nticas. De forma a validar e demonstrar a abordagem proposta, esse trabalho tamb?m apresenta JaphaVM, a primeira M?quina Virtual Java especificamente projetada para mem?ria persistente. Resultados experimentais usando benchmarks e aplica??es reais demonstram que a JaphaVM, na maioria dos casos, executa as mesmas opera??es cerca de uma a duas ordens de magnitude mais rapidamente do que implementa??es equivalentes usando bancos de dados ou arquivos, e, ao mesmo tempo, requer significativamente menos linhas de c?digo. / Current computer systems separate main memory from storage. Programming languages typically reflect this distinction using different representations for data in memory (e.g. data structures, objects) and storage (e.g. files, databases). Moving data back and forth between these different layers and representations compromise both programming and execution efficiency. Recent nonvolatile memory technologies, such as Phase-Change Memory, Resistive RAM, and Magnetoresistive RAM make it possible to collapse main memory and storage into a single layer of persistent memory, opening the way for simpler and more efficient programming abstractions for handling persistence. This Ph.D. thesis introduces a design for the runtime environment for languages with automatic memory management, based on an original combination of orthogonal persistence, persistent memory programming, persistence by reachability, and lock-based failure-atomic transactions. Such design can significantly increase programming and execution efficiency, as in-memory data structures are transparently persistent, without the need for programmatic persistence handling, and removing the need for crossing semantic boundaries. In order to validate and demonstrate the proposed concepts, this work also presents JaphaVM, the first Java Virtual Machine specifically designed for persistent memory. In experimental results using benchmarks and real-world applications, JaphaVM in most cases executed the same operations between one and two orders of magnitude faster than database- and file-based implementations, while requiring significantly less lines of code.