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Développement de procédés d'épitaxie basse température pour les technologies CMOS FD-SOI avancées / Low temperature raised source and drain epitaxy for Fully Depleted Silicon on Insulator (FD-SOI) technologyLabrot, Maxime 05 December 2016 (has links)
Ce travail de thèse s’inscrit dans la technologie de fabrication de transistors à canal mince (Si ou SiGe) totalement déserté sur isolant (Fully-Depleted Silicon-on-Insulator ou FDSOI) qui constitue une option prometteuse pour les nœuds 14nm et au-delà. Les problèmes liés à cette nouvelle technologie sont dus à : (1) l’existence d’instabilités morphologiques conduisant, lors de recuits haute température, à la fragmentation de la couche mince formant le canal, (2) la nécessité d’une reprise d’épitaxie SiGe:B afin de former, sur le canal, des sources et drains surélevées (Raised Source and Drain ou RSD) et (3) des problèmes liés à l’hétérogénéité du dopage induits par l’importance des interfaces substrat/canal, canal/Source et canal/Drain.Ce travail expérimental a été effectué au sein de la société STMicroelectronics en partenariat avec le Centre Interdisciplinaire de Nanoscience de Marseille. Les principaux résultats obtenus sont : 1/ La mise au point, puis l’optimisation d’une méthode de nettoyage de surface à basse température permettant d’éviter la fragmentation du canal observée lors de recuits haute température.2/ L’optimisation des conditions de préparation de la surface du canal permettant de réaliser une bonne reprise d’épitaxie pour les sources et drains surélevées.3/ L’optimisation, via l’incorporation de carbone, des profils de dopage au bore des sources et drains épitaxiés. Les tests électriques effectués sur dispositifs industriels montrent que, grâce aux développements réalisés au cours de ces travaux de thèse, le pourcentage de puces actives sur une plaque est passé de 40% à 90%. / This work concerns the Fully-Depleted Silicon-On-Insulator (FD-SOI) technology, which is a promising option for the technical nodes beyond 14nm.The use of a very thin Si or SiGe channel causes new technological problems due to (1) morphological instabilities that break the film during its high temperature annealing, (2) the necessity to grow Raised Source & Drain (RSD) by epitaxial Chemical-Vapor Deposition (CVD) of SiGe:B, (3) the non-uniformity of the boron profile in the channel because of the number of interfaces (substrate/channel, channel/ source, channel/drain). This experimental work has been performed at STMicroelectronics and Nanoscience Interdisciplinary Center of Marseille laboratory. The main results are:1/ The definition and the improvement of an efficient low temperature surface-cleaning process that avoids the dewetting of the channel.2/ The optimization of the surface preparation of the channel for a subsequent epitaxial growth of RSD materials compatible with electronic requirements.3/ The improvement, via carbon incorporation, of the boron dopant profile in the epitaxially grown RSD. Analysis of electrical devices show that all these improvements lead to a huge enhancement of the percentage of electrical active dies per wafer (from 40% to 90 %).
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Efeitos de estresses bióticos sobre os parâmetros ecofisiológicos e componentes de produção de quatro variedades de cana-de-açúcar / Biotic stresses effects on the ecophysiological parameters and yield components of four sugarcane varietiesSilva, Fábio Leal Santos da 31 July 2015 (has links)
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Brazil is the main world producer of sugarcane (Saccharum ssp.), being the activity of the
Brazilian sugarcane industry in continuous expansion, which can be seen due to increasing
both the production capacity as agricultural areas intended for the cultivation. However, the
increase of the production costs and the expansion of cultivation to less productive areas have
increasingly demanded strategies to safeguard the sector's profitability. In this sense, studies
of environmental factors that limit the yield of sugarcane crops are fundamental and can cite
the biotic stresses caused by pathogenic microorganisms and the weeds. Plants respond
differently to various types of stress, and, in general, are firstly affected in their physiological
and photosynthetic properties. Therefore, the analysis of ecophysiological parameters - being
this a tool to detect small deviations from normality of the photosynthetic performance - can
provide useful information about the behavior of plants under stressful conditions caused by
the disease and weed competition. Thus, this study aimed to evaluate the behavior of four
different sugarcane varieties submitted to the stresses caused by the bacterium Leifsonia xyli
subsp. xyli (Lxx) - causal agent of Ratoon stunting disease (RSD) - and competition with the
weed plant Brachiaria decumbens Stapf., correlating the production data with the
ecophysiological responses resulting from the stress condition. To this finality, stem segments
with just one bud were planted in plastic trays and kept in a greenhouse, being the seedlings
subsequently transplanted to the field, where were measured both yield parameters (biometric
and technological), the fluorescence of chlorophyll a and the gas exchange of plants subject,
or not, to mentioned stressors. The experimental design used was the randomized block
design with four replications, in a split-plot scheme, being the plots composed by varieties Co
997, RB867515, RB92579 and RB951541; and the subplots by the induction or not of stress
factor. Regarding Lxx inoculation, RB92579 and RB951541 varieties were less sensitive to
the RSD effects, since both ecophysiological and yield parameters were just a little bit
affected by disease, while RB867515 and Co 997 varieties underwent changes in many
parameters, highlighting the decline of photosynthetic rate and the reduction of height and
diameter of the stalks. Regarding weed competition with B. decumbens, the four varieties
tested were affected in all parameters, resulting in significant losses of yield, being that the
RB92579 variety showed higher competitive ability than the others. Thus, the use of
ecophysiological analysis tool is feasible to aid the work of selection of tolerant sugarcane
genotypes to typical adverse situations of his cultivation. / O Brasil é o principal produtor mundial de cana-de-açúcar (Saccharum ssp.), entando a
atividade do setor sucroenergético brasileiro em contínua expansão, o que pode ser constatado
devido ao aumento crescente tanto da capacidade produtiva como das áreas agrícolas
destinadas à cultura. No entanto, o aumento dos custos de produção e a expansão do cultivo
para áreas menos produtivas têm exigido cada vez mais estratégias capazes de salvaguardar a
rentabilidade do setor. Nesse sentido, os estudos dos fatores ambientais que limitam o
rendimento dos canavias são fundamentais, podendo-se citar os estresses bióticos causados
pelos microrganismos fitopatogênicos e pelas plantas infestantes. As plantas respondem de
formas diferentes aos diversos tipos de estresse, sendo que, em geral, são primeiramente
afetadas em suas propriedades fisiológicas e fotossintéticas. Isto posto, a análise dos
parâmetros ecofisiológicos – sendo uma ferramenta capaz de detectar pequenos desvios da
normalidade do desempenho fotossintético – pode fornecer informações úteis acerca do
comportamento das plantas sob as condições estressantes causadas por doenças e pela
matocompetição. Assim, o presente estudo teve por objetivo avaliar o comportamento de
quatro diferentes variedades de cana-de-açúcar submetidas aos estresses causados pela
bactéria Leifsonia xyli subsp. xyli (Lxx) – agente causal da doença Raquitismo da soqueira
(RSD) – e pela competição com a planta infestante Brachiaria decumbens Stapf.,
correlacionando os dados de produção com as respostas ecofisiológicas decorrentes da
condição de estresse. Para tal, segmentos de colmo com apenas uma gema foram plantados
em bandejas plásticas e mantidos em casa de vegetação, sendo as mudas posteriormente
transplantadas para o campo, onde foram mensurados os parâmetros de produção (biométricos
e tecnológicos), a fluorescência da clorofila a e as trocas gasosas de plantas sujeitas ou não
aos fatores de estresse mencionados. Foi utilizado o delineamento experimental em blocos
casualizados, com quatro repetições, em esquema de parcelas subdivididas, sendo as parcelas
compostas pelas variedades Co 997, RB867515, RB92579 e RB951541; e as subparcelas pela
imposição ou não do fator de estresse. Em relação à inoculação de Lxx, as variedades
RB92579 e RB951541 foram menos sensíveis aos efeitos do RSD, uma vez que, tanto
parâmetros ecofisiológicos como de produção foram pouco influenciados pela doença, ao
passo que as variedades RB867515 e Co 997 sofreram alterações em diversos parâmetros,
com destaque para o declínio da taxa fotossintética e redução da estatura e diâmetro dos
colmos. Em relação à matocompetição com B. decumbens, as quatro variedades testadas
foram afetadas em todos os parâmetros, acarretando em perdas expressivas de produtividade,
sendo a variedade RB92579 a que demonstrou maior habilidade competitiva. Assim, uso da
ferramenta de análise ecofisiológica é viável no auxílio aos trabalhos de seleção de genótipos
de cana-de-açúcar tolerantes às situações adversas própria do seu cultivo.
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Propuesta de gestión integral para el manejo de residuos sólidos domiciliarios, caso comuna de MaculOgalde Arenas, Pilar January 2018 (has links)
Memoria para optar al título de Geógrafo / La presente investigación tiene por objetivo elaborar una Propuesta de Gestión Integral para el Manejo de Residuos Sólidos Domiciliarios (RSD) para la comuna de Macul. Ella se fundamentó en la implementación de una estrategia de gestión enfocada en la sustentabilidad de este tipo de residuos en una comuna intermedia de la Región Metropolitana de Santiago. Es así que se definen lineamientos de gestión integral presentando una zonificación de gestión jerarquizada de los residuos, aplicando criterios urbanos, ambientales, culturales e institucionales-normativos. En este último punto se prestó especial atención a la Ley 20.920/2016 Ley de Marco parar la Gestión de Residuos, la Responsabilidad Extendida del Productor y Fomento al Reciclaje. Se concluye que el primer esfuerzo para el manejo sustentable de los RSD debe estar enfocado, necesariamente, en el ámbito cultural y en la construcción de un concepto de residuos, basado en su valor intrínseco, dejando de entenderse como algo “descartable” e “inservible” para transformarse en un recurso, lo que debe ser legitimado por la población. Finalmente se generan recomendaciones y un Plan de Acción para dar viabilidad a la propuesta. / The cardinal aim of this following investigation, is to create a built-in proposal of paperwork, for the management of Solid House Wastes (SHW) for the Macul county. It is based on the development of a strategy focused on sustainability of this kind of waste in an average county of the metropolitan area of Santiago.
Therefore, some built-in proposals are defined showing a zone of hierarchy management of the mentioned wastes, using an urban, environmental, cultural and ruled institutions criteria. In this last point, there was special attention to the law 20.920/2016. Law of frame work for the management of wastes, the due responsibility of the producer and encourage of recycling.
It is believed that, the first effort for the management of solid house wastes, must be focused, necessarily, on the cultural environment and in the creation of a concept of waste, based in its inner value, leaving the concepts of “disposable” and “useless” behind, to be transformed into a resource, which must be legitimated by the people. Finally, there are recommendations and an action plan to validate the proposal.
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Avaliação da resistência à Leifsonia xyli subsp. xyli, agente causal do raquitismoda- soqueira (RSD), em variedades comerciais de cana-de-açúcar / Resistance of sugarcane commercial cultivars to Leifsonia xyli subsp. xyli; the causal agent of the ratoon stunting disease (RSD)Gagliardi, Paulo Roberto 07 July 2008 (has links)
A cana-de-açúcar (Saccharum ssp.) é uma das culturas agrícolas mais importantes da história da humanidade. Foi em Nova Guiné, seu provável centro de origem, que o homem teve o primeiro contato com a planta em seu estado silvestre. Atualmente, o Brasil lidera a lista dos 80 países produtores de cana-de-açúcar. É o primeiro também em exportação de seus derivados, seguido, respectivamente, pela Austrália, Tailândia, Guatemala e África do Sul. A área plantada no Brasil está próxima dos 7 milhões de hectares. A cana-de-açúcar, assim como a grande diversidade de culturas de interesse agronômico, é hospedeira de uma série de patógenos que podem limitar sua produção, dentre os quais, destaca-se a bactéria Leifsonia xyli subsp. xyli, agente causal do raquitismo-da-soqueira (RSD). O RSD é considerado uma das mais importantes doenças da cana-de-açúcar que limita a produção no mundo todo e seu controle está fundamentado na adoção de um conjunto de medidas preventivas, pois poucas são as informações sobre materiais resistentes à doença e não existe um produto químico que a controle eficientemente. Historicamente, a dificuldade do diagnóstico do RSD, na maioria dos casos, é conseqüência da ausência de sintomas externos e pela não ocorrência de sintomas internos em determinados cultivares de cana-de-açúcar e neste sentido, técnicas de imunologia, molecular e de microscopia de contraste de fases têm sido bastante empregadas. A hipótese da possível correlação entre a anatomia vascular e a resistência de plantas a patógenos, é um assunto freqüentemente discutido por pesquisadores e poderia elucidar os mecanismos envolvidos na resistência da planta ao patógeno. Assim, o presente trabalho teve como objetivo geral avaliar a resistência/suscetibilidade de 10 variedades comerciais de canade- açúcar RB, mais a variedade CB 49-260 incluída como padrão suscetível, correlacionando os danos apresentados por análises de componentes de produção tecnológicos e biométricos amostrados no campo, com a morfologia e quantificação de conjunto de feixes vasculares e os níveis de infecção detectados nos diagnósticos. Os resultados mostraram que as variedades RB 72 454, RB 83 5486, RB 86 7515, RB 92 8064, RB 92 5211, RB 92 5345 e RB 92 5268 comportaram-se como variedades suscetíveis. A RB 85 5156 comportou-se como variedade de resistência intermediária As variedades RB 85 5536 RB 85 5453, comportaram-se como tolerantes. Os danos apresentados tiveram relação direta com as concentrações do patógeno inoculadas no início do experimento, ou seja, quanto maior a concentração de inóculo, maiores foram os danos ocorridos nas variedades menos tolerantes. Contudo, não há correlações entre o tamanho médio do metaxilema e o número de feixes vasculares por área com a resistência da planta. / Sugarcane (Saccharum ssp.) is one of the most important cultures in the history of the humanity. The center of origin is probably New Guinea, where people had the first contact with the plant in wild state. Presently, Brazil leads the list of the 80 sugarcane producing countries. Brazil is also the first in exporting sugarcane by-products, followed by Australia, Thailand, Guatemala and South Africa, respectively. The are grown in Brazil ranges 7 million hectares. As well as a great diversity of cultures of agronomical interest, sugarcane is host of a large number of pathogens which can limit its production. Among them, one can emphasize, Leifsonia xyli subsp. xyli, causal agent of ratoon stunting disease (RSD). RSD is considered one of the most important diseases of sugarcane limiting yield worldwide and the control is based on the adoption of a set of preventative measures, since the information about resistant materials and efficient chemical products are scarce. Historically, RSD diagnosis has been difficult because there are no definitive external symptoms and internal symptoms do not develop adequately in all varieties. Serological, molecular and microscopy techniques have been widely used to diagnose RSD. The hypothesis of the possible correlation among vascular anatomy and plant resistance has been discussed by researchers and could elucidate the resistance mechanisms involved in the resistance of plants to the pathogens. Thus, the overall objective of the present study was to evaluate the resistance/susceptibility of 10 RB sugarcane commercial varieties including CB 49-260 as a susceptible standard, correlate the damages presented by the analysis of technological and biometric production components of field samples, with the morphology and quantification of set of vascular bundles and the level of infections detected on the diagnostics. The results showed that varieties RB 72 454, RB 83 5486, RB 86 7515, RB 92 8064, RB 92 5211, RB 92 5345 and RB 92 5268 were susceptible. RB 85 5156, had a intermediary resistance and varieties RB 85 5536 and RB 85 5453 both showed tolerant behavior. The injuries presented had a direct relationship with the inoculum concentration, in other words, the higher the inoculum concentration the higher the injuries with the less tolerant varieties. However, there is no correlation between the average length of the metaxilem and the number of vascular bundles per area in plant resistance.
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Direktsamplande digital transciever / Direct sampling digital transceiverKarlsson, Magnus January 2002 (has links)
<p>Master thesis work at ITN (Department of Science and Technology) in the areas of A/D-construction and RF-circuit design. Major goal of project were to research suitable possibilities for implementations of direct conversion in transceivers operating in the 160MHz band, theoretic study followed by development of components in the construction environment Cadence. Suitable A/D- converter and other important parts were selected at the end of the theoretic study. Subsampling technique was applied to make A/D sample requirements more realistic to achieve. Besides lowering requirements on A/D-converter it allows a more simple construction, which saves more components than subsampling adds. Subsampling add extra noise, because of that an A/D-converter based on the RSD algorithm was chosen to improve error rate. To achieve high bit-processing rate compared to the used number of transistors, pipeline structure were selected as conversion method. The receiver was that part which gained largest attention because it’s the part which is most interesting to optimise. A/D-conversion is more difficult to construct than D/A conversion, besides there’s more to gain from eliminating mixers in the receiver than in the transmitter.</p>
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Direktsamplande digital transciever / Direct sampling digital transceiverKarlsson, Magnus January 2002 (has links)
Master thesis work at ITN (Department of Science and Technology) in the areas of A/D-construction and RF-circuit design. Major goal of project were to research suitable possibilities for implementations of direct conversion in transceivers operating in the 160MHz band, theoretic study followed by development of components in the construction environment Cadence. Suitable A/D- converter and other important parts were selected at the end of the theoretic study. Subsampling technique was applied to make A/D sample requirements more realistic to achieve. Besides lowering requirements on A/D-converter it allows a more simple construction, which saves more components than subsampling adds. Subsampling add extra noise, because of that an A/D-converter based on the RSD algorithm was chosen to improve error rate. To achieve high bit-processing rate compared to the used number of transistors, pipeline structure were selected as conversion method. The receiver was that part which gained largest attention because it’s the part which is most interesting to optimise. A/D-conversion is more difficult to construct than D/A conversion, besides there’s more to gain from eliminating mixers in the receiver than in the transmitter.
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Avaliação da resistência à Leifsonia xyli subsp. xyli, agente causal do raquitismoda- soqueira (RSD), em variedades comerciais de cana-de-açúcar / Resistance of sugarcane commercial cultivars to Leifsonia xyli subsp. xyli; the causal agent of the ratoon stunting disease (RSD)Paulo Roberto Gagliardi 07 July 2008 (has links)
A cana-de-açúcar (Saccharum ssp.) é uma das culturas agrícolas mais importantes da história da humanidade. Foi em Nova Guiné, seu provável centro de origem, que o homem teve o primeiro contato com a planta em seu estado silvestre. Atualmente, o Brasil lidera a lista dos 80 países produtores de cana-de-açúcar. É o primeiro também em exportação de seus derivados, seguido, respectivamente, pela Austrália, Tailândia, Guatemala e África do Sul. A área plantada no Brasil está próxima dos 7 milhões de hectares. A cana-de-açúcar, assim como a grande diversidade de culturas de interesse agronômico, é hospedeira de uma série de patógenos que podem limitar sua produção, dentre os quais, destaca-se a bactéria Leifsonia xyli subsp. xyli, agente causal do raquitismo-da-soqueira (RSD). O RSD é considerado uma das mais importantes doenças da cana-de-açúcar que limita a produção no mundo todo e seu controle está fundamentado na adoção de um conjunto de medidas preventivas, pois poucas são as informações sobre materiais resistentes à doença e não existe um produto químico que a controle eficientemente. Historicamente, a dificuldade do diagnóstico do RSD, na maioria dos casos, é conseqüência da ausência de sintomas externos e pela não ocorrência de sintomas internos em determinados cultivares de cana-de-açúcar e neste sentido, técnicas de imunologia, molecular e de microscopia de contraste de fases têm sido bastante empregadas. A hipótese da possível correlação entre a anatomia vascular e a resistência de plantas a patógenos, é um assunto freqüentemente discutido por pesquisadores e poderia elucidar os mecanismos envolvidos na resistência da planta ao patógeno. Assim, o presente trabalho teve como objetivo geral avaliar a resistência/suscetibilidade de 10 variedades comerciais de canade- açúcar RB, mais a variedade CB 49-260 incluída como padrão suscetível, correlacionando os danos apresentados por análises de componentes de produção tecnológicos e biométricos amostrados no campo, com a morfologia e quantificação de conjunto de feixes vasculares e os níveis de infecção detectados nos diagnósticos. Os resultados mostraram que as variedades RB 72 454, RB 83 5486, RB 86 7515, RB 92 8064, RB 92 5211, RB 92 5345 e RB 92 5268 comportaram-se como variedades suscetíveis. A RB 85 5156 comportou-se como variedade de resistência intermediária As variedades RB 85 5536 RB 85 5453, comportaram-se como tolerantes. Os danos apresentados tiveram relação direta com as concentrações do patógeno inoculadas no início do experimento, ou seja, quanto maior a concentração de inóculo, maiores foram os danos ocorridos nas variedades menos tolerantes. Contudo, não há correlações entre o tamanho médio do metaxilema e o número de feixes vasculares por área com a resistência da planta. / Sugarcane (Saccharum ssp.) is one of the most important cultures in the history of the humanity. The center of origin is probably New Guinea, where people had the first contact with the plant in wild state. Presently, Brazil leads the list of the 80 sugarcane producing countries. Brazil is also the first in exporting sugarcane by-products, followed by Australia, Thailand, Guatemala and South Africa, respectively. The are grown in Brazil ranges 7 million hectares. As well as a great diversity of cultures of agronomical interest, sugarcane is host of a large number of pathogens which can limit its production. Among them, one can emphasize, Leifsonia xyli subsp. xyli, causal agent of ratoon stunting disease (RSD). RSD is considered one of the most important diseases of sugarcane limiting yield worldwide and the control is based on the adoption of a set of preventative measures, since the information about resistant materials and efficient chemical products are scarce. Historically, RSD diagnosis has been difficult because there are no definitive external symptoms and internal symptoms do not develop adequately in all varieties. Serological, molecular and microscopy techniques have been widely used to diagnose RSD. The hypothesis of the possible correlation among vascular anatomy and plant resistance has been discussed by researchers and could elucidate the resistance mechanisms involved in the resistance of plants to the pathogens. Thus, the overall objective of the present study was to evaluate the resistance/susceptibility of 10 RB sugarcane commercial varieties including CB 49-260 as a susceptible standard, correlate the damages presented by the analysis of technological and biometric production components of field samples, with the morphology and quantification of set of vascular bundles and the level of infections detected on the diagnostics. The results showed that varieties RB 72 454, RB 83 5486, RB 86 7515, RB 92 8064, RB 92 5211, RB 92 5345 and RB 92 5268 were susceptible. RB 85 5156, had a intermediary resistance and varieties RB 85 5536 and RB 85 5453 both showed tolerant behavior. The injuries presented had a direct relationship with the inoculum concentration, in other words, the higher the inoculum concentration the higher the injuries with the less tolerant varieties. However, there is no correlation between the average length of the metaxilem and the number of vascular bundles per area in plant resistance.
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From state maintenance grants 'to a new child support system: Building a policy for poverty alleviation with special reference to the financial, social, and developmental impacts.Haarmann, Dirk January 1998 (has links)
Philosophiae Doctor - PhD / State social security transfers for families existed in South Africa only in the form of state maintenance grants, which paid up to R700 to single parents. The system was not appropriate in the South African context, being racially biased and financially unsustainable. The Department of Welfare - following in principle the recommendations of the "Lund report" - introduced with effect from 1 April 1998 a child support grant which is payable to the primary care-givers of children, regardless of their family status. The level of benefit was set at RIOOper month per child for children up to the age of six (incl.). The Department declared that 48% or 3 million children should be targeted. At the same time, the SMGs are to be phased out over a three year period. This research was conducted between November 1995 and March 1998. The analysis of the different suggestions during the policy process and the final policy is based on two pillars: • A situation analysis of the living conditions of South Africa's children on the basis of a composite index. • An evaluation of policy scenarios on the basis of a microsimulation model. The index tries to give a complex picture of the living conditions of children by looking at the financial situation, housing, health, and employment opportunities of the households the children are living in. The analysis reveals that nearly 70% of
South Africa's children up to the age of six (incl.) live below the poverty line as defined. A further analysis of the household structure indicates that poorer children are likely to live in larger households. The overall policy shift from a support of single parent families to children in poverty regardless of their family status is espoused. However, the microsimulation model which analyses the impact of different factors like the 'level of benefit', the 'age-cohort', the 'means-test', and the 'administrative requirements', reveals that there are still serious flaws in the current policy. Due to the fact that the means-test is based on the total household income, nearly 40% of the children living below the poverty line are excluded. In addition, the administration needs urgent attention as its capacity is the decisive factor in the success of the programme. The thesis calculates that in the next five years up to R2 billion less will be spent on poor children and the goal of reaching 3 million children will not be achieved, if the problems identified are not addressed. The thesis develops an alternative suggestion to the current policy. While microsimulation has become quite a standard procedure in the analysis of social policies in industrialised countries, there is so far no application in developing countries. It is hoped that by taking this policy analysis as a case-study, this thesis is a step towards the introduction of this method here. Microsimulation models provide important information to enhance the transparency and accountability of policy processes. In this case, civil society was able to challenge Government's decision on a very informed basis, to put pressure on decision makers successfully, and to make workable alternative suggestions. Furthermore, the analysis reveals that against Government's
promise redistribution does not take place. Instead a shift towards a more neo-liberal approach in social policy is observed.
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Desenvolvimento sustentável e agenda de atuação dos bancos públicos comerciais brasileiros: uma análise da estratégia negocial de Desenvolvimento Regional Sustentável (DRS) do Banco do BrasilRejani, Fernando Montrezol 16 March 2011 (has links)
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Previous issue date: 2011-03-16 / This present paper consists in analyzing the business strategy of Regional Sustainable Development (RSD) of Banco do Brasil (BB) under two aspects, of which, i) aims at identifying if the operations of BB, an hybrid Bank, that is public and private at the same time, have headroom to freely operate as an agent of the Brazilian development; and ii) to verify if the RSD business strategy is consistent with its proposed objectives and if those objectives are being achieved, in line with the perception of the BB employees interviewd in this research. The investigation method uses bibliographical research and the application of primary research with the internal agents of BB, responsible for the performance of the national strategy of RSD. Two types of questionnaires were applied to the target audience. In the first group of interviewed stakeholders (managers in strategic and tactical level), the criteria of data analysis was global. For the second group (managers at operational level), the criteria of data analysis was based on a significant sample of a population of 230 business plans of RSD spreaded throughout the country. What can be concluded in this study is that the operation of BB, as an agent of development of Brazil, it has certain inner limitations due from its own hybrid nature. It is made clear a tension that exists between the traditional commercial operation of the Bank (private nature) and its more social operations (public nature) in the implementation of the national strategy of RSD. It is worth noting that, the development promoted by the RSD has a few gaps, mainly in regards to the environmental component of the sustainable development and also in regards to the difficulty in implementing its methodology towards productive activities in the urban environments. However, it is worth highlighting that the social-environmental presence of BB, with the RSD, enables the social inclusion, by way of access to banking and credit, in a much wider aspect than the Brazilian private banks / Este estudo consiste em analisar a estratégia negocial de Desenvolvimento Regional Sustentável (DRS) do Banco do Brasil (BB) sob dois aspectos, nos quais, i) busca identificar se a atuação do BB, um banco híbrido, isto é, de caráter público e privado ao mesmo tempo, tem espaço para atuar de forma livre como agente de desenvolvimento do Estado Brasileiro; e, ii) verifica se a estratégia negocial DRS está coerente com seus objetivos propostos e se esses objetivos estão sendo atingidos, de acordo com a percepção dos funcionários do BB entrevistados nesta pesquisa. O método de investigação utiliza-se de pesquisa bibliográfica e de aplicação de pesquisa primária com os agentes internos ao BB responsáveis pela condução da estratégia negocial DRS. Foram aplicados dois tipos de questionários ao público-alvo. No primeiro grupo de entrevistados (Gerentes em nível estratégico e tático), o critério de análise dos dados foi censitário. Para o segundo grupo (Gerentes em nível operacional), o critério de análise baseou-se em uma amostra significativa de uma população de 230 Planos de Negócios DRS espalhados pelo país. O que se conclui neste estudo é que a atuação do BB, como agente de desenvolvimento do Estado Brasileiro, possui certas limitações intrínsecas à sua própria natureza híbrida. Torna-se claro uma tensão existente entre a atuação comercial tradicional do Banco (natureza privada) e sua atuação mais social (natureza pública) na implementação da estratégia negocial DRS. Cabe ressaltar ainda, que o desenvolvimento promovido pelo DRS possui algumas lacunas, principalmente em relação à componente ambiental do desenvolvimento sustentável e à dificuldade de implementação de sua metodologia às atividades produtivas no meio urbano. Entretanto, cabe destacar que a atuação socioambiental do BB, com o DRS, possibilita a inclusão social, por meio da bancarização e do acesso ao crédito, de forma muito mais ampla que os bancos privados brasileiros
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Mechanism Of Interaction Of Escherichia Coli σ70 With Anti-Sigma FactorsSharma, Umender K 07 1900 (has links)
In bacteria, the RNA polymerase (RNAP) consists of the following subunits: α2, β, β’, ω and σ. The core RNAP (α2ββ’ω) possesses the polymerising activity and it associates with one of the sigma factors to initiate transcription from a promoter region on the DNA template. All bacteria carry an essential housekeeping sigma factor and a number of extra cytoplasmic function (ECF) sigma factors. During alternate physiological states, a major part of transcriptional regulation is carried out by sigma factors, which act as transcriptional switches, thus, making it possible for bacteria to adapt to varied environmental signals by transcribing the necessary set of genes.
Bacteriophages utilise various mechanisms for subverting the bacterial biochemical machinery for their advantage. One such example in E. coli is AsiA protein encoded by an early gene of T4 bacteriophage. Because of its property of binding to σ70, AsiA can inhibit transcription from E. coli promoters bearing –10 and –35 DNA sequences leading to inhibition of growth. σ70 of E. coli is also regulated by a stationary phase specific protein, Rsd, whose major function seems to be helping the cell in switching the transcription in favour of stationary phase genes. In this study we have investigated the mechanism of interaction of T4 AsiA and E. coli Rsd to σ70 of E. coli and also tried to determine the basis of differential inhibition of E. coli growth by AsiA and Rsd.
In chapter one we have reviewed the published literature on regulation of transcription in bacteria. Some of the well known mechanisms of regulating gene expression are: DNA supercoiling, two component signal transduction system (TCS), regulation by alarmone ppGpp and 6S RNA, and sigma-antisigma interactions. Most bacteria carry a number of sigma factors and each of them is dedicated to transcribing genes in response to environmental signals. Intracellular levels of sigma factors and their binding affinity to core RNAP are deciding factors for initiating transcription from specific subsets of genes. In addition, sigma factor activity is also controlled by specific proteins, which bind to sigma factors (anti-sigma factors) under certain environmental conditions. A number of anti-sigma factors have been isolated from a variety of bacteria and the mechanisms of action of binding to cognate sigma factors have been worked out by using genetic, biochemical and structural tools.
In chapter two, using yeast two hybrid assay (YTH), we have identified the regions of σ70 which interact with AsiA, and it was observed that amino acid residues from 547-603, encompassing region 4.1 and 4.2 are involved in binding to σ70. Interestingly, we found that truncated σ70 fragments lacking the N-terminal regions, apparently bound to AsiA with higher affinity compared to full length σ70. As AsiA expression, because of its transcription inhibitory activity, is inhibitory to E.coli growth, co-expression of the truncated C-terminal σ70 fragments (e.g. residues 493-613, σ70C121), which bind to σ70 with high affinity, could relieve growth inhibition. The complex of GST:AsiA-σ70C121 could be purified from E. coli cells. GST:AsiA purified from E .coli cells was found to be associated with RNAP subunits. Since further studies on this interaction required GST:AsiA preparation devoid of RNAP subunits, we decided to express this protein in S. cerevisiae. Bioinformatics analysis indicated the absence of a σ70 homologue in S.cerevisiae. As expected, GST:AsiA purified from the yeast was found to be free from any RNAP like proteins. The protein purified from yeast was used for in-vitro binding experiments.
Our YTH analysis had indicated that deletion a part of region 4.1 or 4.2 of σ70 leads to loss of binding to AsiA. However, the published NMR structure of AsiA in complex with peptides corresponding to region 4 of σ70, showed that either region 4.1 or 4.2 alone can bind to AsiA indicating at the possible existence of two binding sites for AsiA. In order to confirm the physiological significance of this finding, we studied the interaction of truncated σ70 fragments lacking either region 4.1 or 4.2 with AsiA in-vivo in E. coli and in-vitro by affinity pull down assays. It was observed that σ70 fragments lacking either region 4.1 (σ70∆4.1) or 4.2 (σ70∆4.2), did not neutralize the GST:AsiA toxicity, indicating lack of interaction. The affinity purified GST:AsiA from these E. coli cells did not have σ70∆4.1 or σ70∆4.2 associated with it. Similar results were obtained from pull down assays in-vitro, where we found that σ70∆4.1 or σ70∆4.2 do not show any observable interaction with AsiA. This clearly established that the minimum region of σ70 required for physiologically relevant interaction with AsiA consists of both the regions 4.1 and 4.2. Chapter 3 of this thesis has been devoted to this aspect of AsiA-σ70 interaction.
Having defined the minimum region of σ70 interacting with AsiA, we sought to identify the regions and amino acid residues of AsiA, which are critical for interaction with σ70. The approach for identification of mutants and their characterisation has been discussed in chapter 4. For this purpose, we made systematic deletions in the N and C-terminal regions of the protein and also isolated random mutants of AsiA, which lack binding to σ70 and thus are non-inhibitory to E. coli growth. It was found that deletion of 5 amino acids from N-terminus and 17 amino acids from C-terminus did not alter the inhibitory activity of AsiA. In contrast, deletion of N-terminal 10 amino residues led to complete loss of activity, while in the C-terminus, a gradual loss of activity was observed when amino acid residues beyond 17 amino acids were deleted. A 34 amino acids C-terminal deletion mutant was found to be completely inactive. E10K mutant was found to be inactive, but changes of E to other amino acids such as S, Y, L, A and Q were tolerated, indicating that negative charge at E10 is not a crucial element for interaction with σ70. Inactive mutants could be overexpressed in E. coli and showed reduced binding in YTH assay and were also poor inhibitors of in-vivo transcription in E. coli. We concluded that the primary σ70 binding site of AsiA is present in the N-terminus, yet C-terminal 64-73 amino acid residues are required for effective binding in-vivo. These studies also correlate the inhibitory potential of AsiA with its σ70 binding proficiency.
In chapter 5, we have made a comparative analysis of mechanism of interaction of AsiA and Rsd to E. coli RNAP. Overexpression of Rsd was found to be less inhibitory to E. coli cell growth than that of AsiA. The affinity purified GST-AsiA from E. coli was found to have all the RNAP subunits associated with it, whereas, only σ70 was found to be associated with similarly purified GST:Rsd, pointing towards differences in binding to RNAP. In affinity pull down assays, in-vitro, it was found that both AsiA and Rsd do not show any observable binding to core RNAP. Binding of AsiA to σ70 in holo RNAP led to the formation of a ternary complex, whereas no ternary complex was observed when Rsd was made to interact with holo RNAP. Analysis of protein-protein interaction by YTH showed that region 4.1 and 4.2 are critical for binding of both AsiA and Rsd to σ70. However, in the case of Rsd, the surface of interaction is not limited to this region only and other regions of σ70 make significant contribution to this binding. Possibly, the interaction of Rsd with the core binding regions of σ70 prevents its association with core RNAP. Kinetic analysis of binding by surface plasmon resonance (SPR) showed that binding affinities (Kd) of AsiA and Rsd to σ70 are in similar range. Therefore, we concluded that the ability of AsiA to trap the holo RNAP is, probably, responsible for higher inhibitory activity of this protein compared to that of Rsd.
Thus, T4 AsiA and E. coli Rsd, which share regions of interaction on σ70, have evolved differences in their mechanism of binding to RNAP such that T4 AsiA, by trapping the holo RNAP subverts the complete bacterial transcription machinery to transcribe its own genes. Rsd, on the other hand, has evolved to interact primarily with σ70, which favours the utilisation of core RNAP by other sigma factors.
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