Além de separar claramente os papéis de instituições voltadas ao acolhimento de crianças e adolescentes enquanto medida de proteção (abrigos) e os de instituições voltadas ao cumprimento de medidas sócio-educativas, o Estatuto da Criança e do Adolescente (ECA,1990) propõe novas diretrizes para o acolhimento de crianças e adolescentes que ainda estão longe de serem completamente implementadas por todas as instituições brasileiras. Esta pesquisa analisa o contexto institucional, rotinas, práticas cotidianas e estrutura física de dois abrigos voltados ao acolhimento de adolescentes do município de Porto Alegre – um governamental e uma ONG – com o objetivo de identificar possíveis diversidades nas práticas destas instituições e avaliar se esses ambientes de abrigo estão oferecendo um espaço referencial e reorganizador para os abrigados. A pesquisa investiga também se estes ‘novos’ ambientes estão conseguindo oferecer um espaço continente e de ressignificação das experiências traumáticas anteriores que levaram à situação de abrigamento, reconhecendo quais práticas se distinguem das executadas nas grandes instituições. A pesquisa segue uma metodologia qualitativa, de caráter descritivo, denominada ‘descrição de cunho etnográfico’. Para a análise dos dados, utilizou-se o método de Análise de Conteúdo das narrativas dos adolescentes e adultos entrevistados. Os resultados apontam para a importância de um acolhimento personalizado e em pequenas unidades onde é possível oferecer um acolhimento mais continente ao processo adolescente, e o reconhecimento da importância dos adultos cuidadores, especialmente monitores, como pessoas significativas para os adolescentes. Ainda em relação ao importante papel dos monitores, a pesquisa levanta vários questionamentos em relação aos papéis atribuídos a estes monitores e sobre as dificuldades no atendimento quando ao invés de serem cuidadores, no sentido mais amplo da palavra, esses adultos se tornam apenas pessoas destinadas a controlar e monitorar a vida dos abrigados. A pesquisa investiga ainda a intricada relação entre o caráter provisório da medida de proteção, preconizada pelo ECA, e a necessidade do estabelecimento de vínculos entre cuidadores e abrigados e de realizar um trabalho de médio e longo prazo, visando ressignificar suas histórias. / In addition to clearly separating the roles of institutions oriented towards the protection of children and adolescents between those which serve as measures of protection (shelters) and those of a social-educative orientation, the Child and Adolescent Statute (ECA, 1990) proposes new directives for sheltering children and adolescents, although, as of the present date, not all Brazilian institutions have fully implemented these guidelines. This current research analyses the institutional context, routines, daily practices and physical structures of two shelters that receive children and adolescents in the town of Porto Alegre – one governmental and the other non-governmental (NGO) – with the principal goal of identifying possible differences between the practices of these two institutions and evaluating if these shelter environments are offering referential and reorganising spaces to the sheltered. This research also investigates whether these ‘new’ environments are offering a continent space, capable of promoting resignification of the previous traumatic experiences that lead to sheltering, whilst identifying the practices which are distinct from those conducted at large institutions. The research follows a descriptive, qualitative methodology, called 'description of an ethnographic nature', based on the Content Analysis method of the narratives of interviewed adults and adolescents. The results point towards the importance of both personalised attendance and the use of small units, where it is possible to offer a more continent holding of the adolescent process, and shows the importance of the caring adults, especially the monitors, as meaningful figures to the adolescents. With respect to the important role of the monitors, this research raises several questions related to the roles attributed to these monitors and to the difficulties observed when, instead of taking care of the adolescents, the monitors are focus purely on the control and observation of the sheltered ones lives. This research also investigates the intricate relationship between the provisory nature of the measure of protection, as praised by ECA, and the need to establish bonds between the carers and the sheltered, as well as the necessity of a medium and long-term continuation of the holding process, as a means of permitting a resignification of the sheltered-one’s life stories.

Esta pesquisa propõe uma reflexão sobre a produção da imagem fotográfica e seus desdobramentos num processo artístico. Busca investigar a presença de procedimentos adotados por artistas que pretendem ampliar o conceito de imagem fixa, propondo alterações formais e conceituais com uso de materiais diversos. O texto apresenta análises sobre obras de artistas contemporâneos em relação com os procedimentos adotados no meu processo artístico. Desta maneira, instaura-se um campo de interação entre vários modos do fazer artístico. Durante a construção desta tese, foram identificados núcleos de análises que norteiam a organização do pensamento sobre minha conduta criadora, constituindo assim, categorias de ações e reflexões sobre imagens transitórias e as dinâmicas interativas entre o real e o imaginário nos procedimentos fotográficos. As operações poéticas, aqui apresentadas, envolvem experiências com uso de imagens fotográficas que retornam ao tipo de material ou situação que lhe deu origem, assim como o uso de materiais que se associam de maneira metafórica ou metonímica. Tais escolhas, por consequência, promovem alterações nas qualidades visuais das imagens produzidas, fator importante para discutir o “valor” da imagem no cotidiano e seu estado transitório. Assim, os desvios produzidos nos registros fotográficos foram fundamentais para ampliar o conceito da fotografia documental e da fotografia artística, discutido aqui, a partir de uma articulação prática e reflexiva das “marcas do visível”. / This research aims at a reflection about the production of the photographic image and its unfoldings in an artistic process. It tries to investigate the presence of procedures applied by artists who intend to enlarge the concept of steady image, proposing formal and conceptual changes with various materials. The text presents some analyses about works of contemporary artists in relation with the procedures applied in my artistic process. Hence, it is established a field of interaction among various kinds of art making. During the writing of this thesis, it was possible to identify nucleuses of analyses that guide the thought organization about creating conduct, constituting this way, categories of actions and reflections about transitory images and the interactive dynamics between what is real and what is imaginary in photographic procedures. The poetic operations, here presented, involve experiences with use of photographic images that return to the type of material or situation from which it originated, as well as the use of materials that are associated in a metaphoric way. Such choices, as a consequence, generate changes in the visual qualities of the images produced, an important factor to discuss the “value” of the image on a regular basis and its transitory state. Therefore, the deviations produced in the photographic registers were fundamental to enlarge the concept of the documental photography, discussed here, beginning from a practical and reflexive articulation of the “marks of visible”.

Além de separar claramente os papéis de instituições voltadas ao acolhimento de crianças e adolescentes enquanto medida de proteção (abrigos) e os de instituições voltadas ao cumprimento de medidas sócio-educativas, o Estatuto da Criança e do Adolescente (ECA,1990) propõe novas diretrizes para o acolhimento de crianças e adolescentes que ainda estão longe de serem completamente implementadas por todas as instituições brasileiras. Esta pesquisa analisa o contexto institucional, rotinas, práticas cotidianas e estrutura física de dois abrigos voltados ao acolhimento de adolescentes do município de Porto Alegre – um governamental e uma ONG – com o objetivo de identificar possíveis diversidades nas práticas destas instituições e avaliar se esses ambientes de abrigo estão oferecendo um espaço referencial e reorganizador para os abrigados. A pesquisa investiga também se estes ‘novos’ ambientes estão conseguindo oferecer um espaço continente e de ressignificação das experiências traumáticas anteriores que levaram à situação de abrigamento, reconhecendo quais práticas se distinguem das executadas nas grandes instituições. A pesquisa segue uma metodologia qualitativa, de caráter descritivo, denominada ‘descrição de cunho etnográfico’. Para a análise dos dados, utilizou-se o método de Análise de Conteúdo das narrativas dos adolescentes e adultos entrevistados. Os resultados apontam para a importância de um acolhimento personalizado e em pequenas unidades onde é possível oferecer um acolhimento mais continente ao processo adolescente, e o reconhecimento da importância dos adultos cuidadores, especialmente monitores, como pessoas significativas para os adolescentes. Ainda em relação ao importante papel dos monitores, a pesquisa levanta vários questionamentos em relação aos papéis atribuídos a estes monitores e sobre as dificuldades no atendimento quando ao invés de serem cuidadores, no sentido mais amplo da palavra, esses adultos se tornam apenas pessoas destinadas a controlar e monitorar a vida dos abrigados. A pesquisa investiga ainda a intricada relação entre o caráter provisório da medida de proteção, preconizada pelo ECA, e a necessidade do estabelecimento de vínculos entre cuidadores e abrigados e de realizar um trabalho de médio e longo prazo, visando ressignificar suas histórias. / In addition to clearly separating the roles of institutions oriented towards the protection of children and adolescents between those which serve as measures of protection (shelters) and those of a social-educative orientation, the Child and Adolescent Statute (ECA, 1990) proposes new directives for sheltering children and adolescents, although, as of the present date, not all Brazilian institutions have fully implemented these guidelines. This current research analyses the institutional context, routines, daily practices and physical structures of two shelters that receive children and adolescents in the town of Porto Alegre – one governmental and the other non-governmental (NGO) – with the principal goal of identifying possible differences between the practices of these two institutions and evaluating if these shelter environments are offering referential and reorganising spaces to the sheltered. This research also investigates whether these ‘new’ environments are offering a continent space, capable of promoting resignification of the previous traumatic experiences that lead to sheltering, whilst identifying the practices which are distinct from those conducted at large institutions. The research follows a descriptive, qualitative methodology, called 'description of an ethnographic nature', based on the Content Analysis method of the narratives of interviewed adults and adolescents. The results point towards the importance of both personalised attendance and the use of small units, where it is possible to offer a more continent holding of the adolescent process, and shows the importance of the caring adults, especially the monitors, as meaningful figures to the adolescents. With respect to the important role of the monitors, this research raises several questions related to the roles attributed to these monitors and to the difficulties observed when, instead of taking care of the adolescents, the monitors are focus purely on the control and observation of the sheltered ones lives. This research also investigates the intricate relationship between the provisory nature of the measure of protection, as praised by ECA, and the need to establish bonds between the carers and the sheltered, as well as the necessity of a medium and long-term continuation of the holding process, as a means of permitting a resignification of the sheltered-one’s life stories.

Além de separar claramente os papéis de instituições voltadas ao acolhimento de crianças e adolescentes enquanto medida de proteção (abrigos) e os de instituições voltadas ao cumprimento de medidas sócio-educativas, o Estatuto da Criança e do Adolescente (ECA,1990) propõe novas diretrizes para o acolhimento de crianças e adolescentes que ainda estão longe de serem completamente implementadas por todas as instituições brasileiras. Esta pesquisa analisa o contexto institucional, rotinas, práticas cotidianas e estrutura física de dois abrigos voltados ao acolhimento de adolescentes do município de Porto Alegre – um governamental e uma ONG – com o objetivo de identificar possíveis diversidades nas práticas destas instituições e avaliar se esses ambientes de abrigo estão oferecendo um espaço referencial e reorganizador para os abrigados. A pesquisa investiga também se estes ‘novos’ ambientes estão conseguindo oferecer um espaço continente e de ressignificação das experiências traumáticas anteriores que levaram à situação de abrigamento, reconhecendo quais práticas se distinguem das executadas nas grandes instituições. A pesquisa segue uma metodologia qualitativa, de caráter descritivo, denominada ‘descrição de cunho etnográfico’. Para a análise dos dados, utilizou-se o método de Análise de Conteúdo das narrativas dos adolescentes e adultos entrevistados. Os resultados apontam para a importância de um acolhimento personalizado e em pequenas unidades onde é possível oferecer um acolhimento mais continente ao processo adolescente, e o reconhecimento da importância dos adultos cuidadores, especialmente monitores, como pessoas significativas para os adolescentes. Ainda em relação ao importante papel dos monitores, a pesquisa levanta vários questionamentos em relação aos papéis atribuídos a estes monitores e sobre as dificuldades no atendimento quando ao invés de serem cuidadores, no sentido mais amplo da palavra, esses adultos se tornam apenas pessoas destinadas a controlar e monitorar a vida dos abrigados. A pesquisa investiga ainda a intricada relação entre o caráter provisório da medida de proteção, preconizada pelo ECA, e a necessidade do estabelecimento de vínculos entre cuidadores e abrigados e de realizar um trabalho de médio e longo prazo, visando ressignificar suas histórias. / In addition to clearly separating the roles of institutions oriented towards the protection of children and adolescents between those which serve as measures of protection (shelters) and those of a social-educative orientation, the Child and Adolescent Statute (ECA, 1990) proposes new directives for sheltering children and adolescents, although, as of the present date, not all Brazilian institutions have fully implemented these guidelines. This current research analyses the institutional context, routines, daily practices and physical structures of two shelters that receive children and adolescents in the town of Porto Alegre – one governmental and the other non-governmental (NGO) – with the principal goal of identifying possible differences between the practices of these two institutions and evaluating if these shelter environments are offering referential and reorganising spaces to the sheltered. This research also investigates whether these ‘new’ environments are offering a continent space, capable of promoting resignification of the previous traumatic experiences that lead to sheltering, whilst identifying the practices which are distinct from those conducted at large institutions. The research follows a descriptive, qualitative methodology, called 'description of an ethnographic nature', based on the Content Analysis method of the narratives of interviewed adults and adolescents. The results point towards the importance of both personalised attendance and the use of small units, where it is possible to offer a more continent holding of the adolescent process, and shows the importance of the caring adults, especially the monitors, as meaningful figures to the adolescents. With respect to the important role of the monitors, this research raises several questions related to the roles attributed to these monitors and to the difficulties observed when, instead of taking care of the adolescents, the monitors are focus purely on the control and observation of the sheltered ones lives. This research also investigates the intricate relationship between the provisory nature of the measure of protection, as praised by ECA, and the need to establish bonds between the carers and the sheltered, as well as the necessity of a medium and long-term continuation of the holding process, as a means of permitting a resignification of the sheltered-one’s life stories.

Ce travail présente la synthèse et l’étude d’une nouvelle famille de composés photochromes de type di(hétéroaryl)éthène ainsi que leur utilisation comme ligand pontant en chimie de coordination dans le but d’élaborer des matériaux moléculaires à propriétés photomodulables. Depuis ces dernières années, le photochromisme occupe une place prépondérante dans le développement de nouveaux matériaux photosensible.Ainsi, de nouveaux di(hétéroaryl)éthènes, dérivés de terarylènes, ont été synthétisés et leurs propriétés photochromes ont été étudiées en détail. Ces nouveaux systèmes, baptisés tétrarylènes, ont également permis l’obtention de composés dissymétriques présentant un biphotochromisme exclusif. Enfin, ces tétrarylènes ont pu être utilisés pour la synthèse de complexes mono- et di-nucléaires de Cu(II). Certains cas ont alors révélé l’éjection réversible du métal de la cavité chélatante par étude RPE.Mots clés : photochromisme, diaryléthènes, terarylènes, commutation, Absorption transitoire, chimie de coordination, RPE / This work deals with the synthesis and study of a new family of photochromic di(heteroaryl)ethenes as well as their use as bridging ligand in coordination chemistry in order to design photo-switchable molecular materials. Over the past few years, the interest of the scientific world to photochromism is growing for its potential use in optical memory devices, optoelectronic or any others photonic devices.Thus, new di(heteroaryl)ethenes, structurally close from terarylenes, have been synthesized and their photochromic properties have been studied in depth. These new systems, called tetrarylènes, enable us to obtain biphotochromic compounds, introducing dissymmetry in the structure. Synthesis of mono- and di-nuclear copper(II) complexes can be performed using these tetrarylenes. Some cases revealed, by EPR study, the reversible release and uptake of the metal ion in solution upon irradiation.Key-words : photochromism, diarylethenes, terarylenes, switches, transitory absorption, Coordination chemistry, EPR

Os projetos de redes hidráulicas dimensionam a capacidade de vazão e pressão para atender a uma demanda e prever a resistência necessária para garantir a estabilidade da instalação. Os esforços solicitantes não deverão ultrapassar as resistências estruturais, mantendo-se um coeficiente de segurança que garanta a estabilidade, mesmo nos casos de falhas operacionais. Deve-se proceder à simulação hidráulica tanto para o regime permanente quanto para o regime transitório. Na fase operacional haverão situações transitórias ocasionadas por manobras intencionais ou falhas não previstas que provocarão mudanças do regime permanente para o regime transitório, cuja variação de carga é diretamente proporcional à velocidade de propagação da onda ou celeridade e, dependendo da intensidade do transitório hidráulico, haverá a necessidade de instalar dispositivos de proteção de redes. A concepção dos dispositivos de proteção baseia-se na dissipação do fenômeno transitório por meios de descargas, amortecimento em câmaras de ar comprimido e por reservatórios intermediários que absorvem e suprem os picos de pressão e vazão no início da perturbação, de tal forma que a onda de pressão seja controlada. A celeridade, por sua vez, é função das características do meio fluido, do material da tubulação e da geometria. Ao provocar uma mudança na compressibilidade do meio fluido, tem-se redução no coeficiente de compressibilidade volumétrico da mistura fluida que vai ocasionar uma redução na velocidade de propagação da onda ou celeridade, amortecendo o impacto da variação de carga para níveis que possam ser absorvidos pela instalação. Esta dissertação aborda um dispositivo de redução da velocidade de propagação ou celeridade que pode ser usado como proteção de redes hidráulicas ou atenuador de celeridade, que junto com outros dispositivos e associados em série, distribuídos ao longo da tubulação, podem absorver os excessos de pressão e vazão gerados pelos transitórios e manter os esforços solicitantes inferiores à resistência oferecida pela instalação. / The projects of hydraulic networks define the capacity of outflow and pressure to meet a demand and to achieve the necessary resistance to guarantee the installation stability. The applied loading must not exceed structural resistance, there remaining a safety coefficient which guarantees the stability even in case of operational failure. The hydraulic simulation must be performed both for permanent and transitory regime. In the operational phase, there will be transitory situations caused by intentional maneuvers or unpredicted failures which will cause changes from permanent to transitory regime, with changes in load directly proportional to the propagation speed of the wave or celerity and, depending on the intensity of the hydraulic transient, it will be necessary to provide devices for the network protection. The conception of protection devices is based on the transient phenomena dissipation by means of discharges, shock absorption in air compressed chambers and though intermediate reservoirs, which absorb and supply the outflow and pressure peaks in the beginning of the disturbance. This dissertation approaches a device so that the pressure wave is controlled. The celerity, in its turn, is a function of the fluid characteristics, the network material and geometry. Provoking a change in the mean fluid compressibility there is a reduction in the volumetric compressibility coefficient and also in the specific mass of the mixture, which will cause a reduction in the speed of propagation of the wave or celerity, cushioning the impact of the pressure head variation to a level that can be absorbed by the installation. Therefore, the reduction in the speed of propagation or celerity canbe used is as a protection device for hydraulic nets, or celerity attenuation, which together with other devices, associated in series and distributed along the duct may absorb the excess of pressure and outflow generated by the transitory and keep the applied loading inferior to the resistance supplied by the installation.

In der vorliegenden Arbeit wurden cDNAs, kodierend für bisher unbekannte stärkeabbauende Enzyme, aus Kartoffel isoliert und funktionell analysiert. Die Isolation der cDNAs erfolgte mit Hilfe eines Systems, welches sich der funktionellen Expression von cDNA-Bibliotheken in E. coli bediente. Die mit diesem System zur Expression gebrachten cDNA-Bibliotheken wurden im Rahmen dieser Arbeit hergestellt. Zum einen handelte es sich um eine blattspezifische Phagen-cDNA-Bibliothek (Proben wurden während des Tag/Nacht Übergangs genommen), zum anderen um eine knollenspezifische cDNA-Bibliothek aus kaltgelagerten Knollen. Nach der Überführung der Phagen-Bibliotheken in Plasmid-Bibliotheken wurden diese funktionell in dem E. coli Stamm KV832 exprimiert. Der Stamm KV832 wurde aufgrund seiner Fähigkeit, lineare Glucane zu akkumulieren, ausgewählt. Werden Glucan akkumulierende KV832 Kolonien mit Jod bedampft, so zeigen diese eine typische Blaufärbung. Nach der Expression der Plasmid-Bibliotheken in KV832 wurden solche Kolonien weiter untersucht, welche in ihrer Färbung von den blauen Kolonien abwichen. Mittels eines zweiten E. coli Stamms, PGM −, welcher ebenfalls in der Lage ist, lineare Glucane zu akkumulieren, wurden die Ergebnisse für KV832 bestätigt. Die funktionelle Expression der Bibliotheken führte zur Isolation einer Reihe von unbekannten cDNAs. Zwei dieser cDNAs wurden im Rahmen dieser Arbeit weiterführend untersucht. Zum einen handelte es sich um eine cDNA, die für eine bis dahin unbekannte β-Amylase aus Kartoffel kodierte und deren Homolog aus Arabidopsis (CT-BMY) im Laufe dieser Arbeit von Lao et al. (1999) veröffentlicht wurde, zum anderen um eine cDNA, die für ein unbekanntes Enzym kodierte (DSD10). Das Arabidopsis Homolog zu DSD10 wurde im Zuge der Arabidopsis Genominitiative Ende 2000 publiziert. Im Rahmen dieser Arbeit konnte gezeigt werden, dass die isolierte β-Amylase cDNA für eine funktionelle β-Amylase kodiert und dieses Enzym in der Lage ist, neben löslicher auch rohe Stärke anzugreifen. Lokalisationsexperimente zeigten, dass das Enzym in isolierte Erbsenchloroplasten importiert wurde und dass die 100 N-terminalen Aminosäuren für den Import in die Plastiden ausreichten. Die β-Amylase wurde als PCT-BMYI bezeichnet. Die »antisense«-Inhibierung von PCT-BMYI führte zu einem Hochstärke-Phänotyp der Blätter, sowie zu einem Anstieg der Trockenmasse. Der Hochstärke-Phänotyp ist auf eine Reduktion der Stärkemobilisierung und die daraus folgende Akkumulation der Stärke während der Vegetationsperiode zurückzuführen. Damit konnte erstmals die physiologische Bedeutung einer β-Amylase für den Abbau der transitorischen Stärke gezeigt werden. Kein Einfluss zeigte die »antisense« Inhibierung von PCT-BMYI auf den kälteinduzierten Abbau der Speicherstärke in Knollen. Es konnte auch kein Unterschied im Keimverhalten oder der Entwicklung der neuen Pflanze beobachtet werden. Ein Teil der Ergebnisse zu PCT-BMYI wurde bereits publiziert (Scheidig et al., 2002). Die isolierten cDNAs dsd10, sgeI (die Volllängen cDNA zu dsd10) und das Arabidopsis Homolog asgeI kodieren für Enzyme, welche α-Amylase-Aktivität besitzen, aber keine Homologie zu bekannten α-Amylasen aufweisen. Ein mögliches Glucoamylase Motiv erwies sich für die Aktivität des Proteins als essentiell. Lokalisationsexperimente deuteten auf den Import des SGEI Proteins in isolierte Erbsenchloroplasten hin. Die »antisense«-Inhibierung von sgeI führte in den entsprechenden Linien zu einem Hochstärke-Phänotyp in Blättern, einem Anstieg der Trockenmasse in Blättern, sowie zu größeren Stärkekörnern in einer der untersuchten Linien. Ein nicht erwarteter Effekt zeigte sich in Blättern der entsprechenden Linien, welche für längere Zeit dunkel gehalten wurden. Die Blätter der untransformierten Kontrolle waren abgestorben, wohingegen die Blätter der SGEI »antisense« Linien grün und vital erschienen. Die α- und β-Amylase-Aktivität war in Blättern der SGEI »antisense« Linien reduziert, weshalb eine genaue Zuordnung der Funktion von SGEI nicht möglich war. Die vorliegenden Ergebnisse zu den SGEI »antisense« Linien deuten aber darauf hin, dass der beobachtete Hochstärke-Phänotyp nicht alleine auf die Reduktion der β-Amylase-Aktivität zurückzuführen ist. Ein Einfluss von SGEI auf den kälteinduzierten Abbau der Speicherstärke konnte nicht beobachtet werden. Es konnte auch hier kein Unterschied im Keimverhalten oder der Entwicklung der neuen Pflanze beobachtet werden. / In the presented work, previously unidentified starch metabolic genes from potato were isolated and functionally characterized. Gene isolation proceeded using a cDNA library system that allows the functional expression of potato genes in E. coli. The generated libraries included 1) a phage vector-based, leaf-specific cDNA library generated from mRNA isolated during the day/night transition and 2) a phage vector-based, tuber-specific cDNA library generated from mRNA isolated from potato tubers after cold storage. After in vivo mass Excision of the phage library, the resulting plasmid libraries were functionally expressed in E. coli strain, KV832. This strain was selected for its ability to accumulate linear glucans. Reaction with iodine vapour in glucan-producing KV832 colonies results in a characteristic blue hue. The expression library was thus screened for colonies in which the blue hue was diminished, a potential indicator of the expression of starch degrading enzymes. Library clones from the selected colonies were reconfirmed in PGM−, an alternative E. coli that also accumulates linear glucans. The above expression and screening program allowed isolation of a series of previously uncharacterized cDNA clones. Two such clones were investigated in depth in the remainder of the presented work. The first of these cDNA clones comprised a gene for a hitherto unidentified β-amylase function. The second encoded a functional truncation of a previously unknown enzyme, and was designated DSD10. The full length version of this gene was isolated and designated sgeI. Homologs of both full-length genes have since been identified in Arabidopsis: the former was published as CT-BMY by Lao et al. (1999), while the latter was published in the course of the Arabidopsis Genome Initiative at the end of 2000. Demonstrated in the course of this work is that the first of these isolated amylase cDNAs encodes a functional β-amylase enzyme that hydrolyses raw as well as soluble starch. Enzyme localization experiments showed that the 100 N-terminal amino acids are sufficient to effect import into isolated pea chloroplasts, which is supportive of plastid-targeted localization in potato. This novel β-amylase was designated as PCT-BMYI. Whole-plant antisense inhibition of PCT-BMYI in the potato plant resulted in a high-starch phenotype in the leaf, as well as to an increase in leaf dry weight. The high-starch phenotype was caused by a reduction in starch mobilization and the resulting accumulation of starch during the vegetative phase. This represents the first demonstration of the physiological role of a β-amylase in the metabolism of transitory starch deposits. In contrast to its role in the leaf, antisense inhibition of PCT-BMY1 resulted in no observable alteration in cold-induced metabolism of storage starch in the potato tuber. Additionally, inhibition of PCT-BMY1 resulted in no observable alteration in tuber sprouting, nor in the development of the potato plants. A portion of the results regarding PCT-BMYI have been published (Scheidig et al., 2002). The second isolated gene, sgeI, and its Arabidopsis homolog, asgeI, encode enzymes with α-amylase activity, but neither show homology to known α-amylases. A putative glucoamylase motif, however, was found to be essential for activity of the sgeI gene product, SGEI. As was the case for PCT-BMY1, localization experiments demonstrated import of SGEI into isolated pea chloroplasts, again suggesting plastid localization in potato. Antisense inhibition of sgeI in potato lead to a high-starch phenotype in the leaf and an increase in the leaf dry weight, but also to an increase in starch granule size in one of the studied potato lines. Longer term storage of such lines in the absence of light resulted in an unexpected phenomenon. While the wild type control leaves withered and died within days, the sgeI antisense lines appeared green and healthy for over two weeks. The reason for this may be the metabolism of the stored, hyper-accumulated starch, both due to and despite the initial antisense suppression of sgeI. The exact roll of SGEI in these experiments was complicated by the observed simultaneous suppression of both α- und β-amylase activity in the sgeI antisense lines. The clear quantitative differences in the observed high-starch phenotypes of the sgeI and PCT-BMY1 lines, however, suggest that these phenotypic differences were not due to suppression of β-amylase activity alone. SGEI suppression resulted in no observed differences in sprouting, development of potato plants, or in the metabolism of storage starch in the potato tuber.

This thesis contributes to the discussion on the importance of accounting information for stock market efficiency. As any analysis of market efficiency depends on the use of adequate risk proxies, the thesis first investigates the ability of commonly used risk factors to explain the cross-sectional variation of Swedish stock returns. The findings suggest that capturing risk is indeed very complicated, as neither CAPM beta nor size and book-to-market equity ratio are significantly associated with realized monthly returns. The relative bid-ask spread is found to be the strongest of all the analyzed factors; nevertheless it does not seem to be related to momentum in the manner predicted in the conceptual argument presented earlier in the paper. Second, the thesis documents that simple accounting summary measures, such as earnings and book value of equity, can be used as benchmarks for the identification of mispriced stocks. Contrarian investment strategies (CISs) based on these simple measures earn a substantial value premium of 11-14%. In addition, we find that their effectiveness is compromised by noise that is caused by transitory earnings and accounting conservatism. Controlling for these factors increases the magnitude of the value premium and improves the consistency of the CIS. This suggests that the information reflected in key accounting measures is not fully reflected in stock prices. Finally, this thesis shows that the structure of accounting information matters too. It documents that the transition from the Swedish GAAP to IFRS in 2005 not only changed the average goodwill charges reported by companies, but also affected valuation of goodwill-intensive companies. This suggests that investors were not able to see through the conservative treatment of goodwill prior to the adoption of IFRS and that they recognized its higher persistence only after being provided with accounting information directly highlighting it. It is sometimes suggested that the structure of financial reporting “per se” should not be relevant to the valuation of companies, because the presentation itself does not the affect expected operating performance and because investors and analysts can “see through” and properly discount for various reporting formats. This thesis concludes that, contrary to this proposition, the structure of accounting does matter for equity valuation and that changes in representation do impact on stock prices.

Os projetos de redes hidráulicas dimensionam a capacidade de vazão e pressão para atender a uma demanda e prever a resistência necessária para garantir a estabilidade da instalação. Os esforços solicitantes não deverão ultrapassar as resistências estruturais, mantendo-se um coeficiente de segurança que garanta a estabilidade, mesmo nos casos de falhas operacionais. Deve-se proceder à simulação hidráulica tanto para o regime permanente quanto para o regime transitório. Na fase operacional haverão situações transitórias ocasionadas por manobras intencionais ou falhas não previstas que provocarão mudanças do regime permanente para o regime transitório, cuja variação de carga é diretamente proporcional à velocidade de propagação da onda ou celeridade e, dependendo da intensidade do transitório hidráulico, haverá a necessidade de instalar dispositivos de proteção de redes. A concepção dos dispositivos de proteção baseia-se na dissipação do fenômeno transitório por meios de descargas, amortecimento em câmaras de ar comprimido e por reservatórios intermediários que absorvem e suprem os picos de pressão e vazão no início da perturbação, de tal forma que a onda de pressão seja controlada. A celeridade, por sua vez, é função das características do meio fluido, do material da tubulação e da geometria. Ao provocar uma mudança na compressibilidade do meio fluido, tem-se redução no coeficiente de compressibilidade volumétrico da mistura fluida que vai ocasionar uma redução na velocidade de propagação da onda ou celeridade, amortecendo o impacto da variação de carga para níveis que possam ser absorvidos pela instalação. Esta dissertação aborda um dispositivo de redução da velocidade de propagação ou celeridade que pode ser usado como proteção de redes hidráulicas ou atenuador de celeridade, que junto com outros dispositivos e associados em série, distribuídos ao longo da tubulação, podem absorver os excessos de pressão e vazão gerados pelos transitórios e manter os esforços solicitantes inferiores à resistência oferecida pela instalação. / The projects of hydraulic networks define the capacity of outflow and pressure to meet a demand and to achieve the necessary resistance to guarantee the installation stability. The applied loading must not exceed structural resistance, there remaining a safety coefficient which guarantees the stability even in case of operational failure. The hydraulic simulation must be performed both for permanent and transitory regime. In the operational phase, there will be transitory situations caused by intentional maneuvers or unpredicted failures which will cause changes from permanent to transitory regime, with changes in load directly proportional to the propagation speed of the wave or celerity and, depending on the intensity of the hydraulic transient, it will be necessary to provide devices for the network protection. The conception of protection devices is based on the transient phenomena dissipation by means of discharges, shock absorption in air compressed chambers and though intermediate reservoirs, which absorb and supply the outflow and pressure peaks in the beginning of the disturbance. This dissertation approaches a device so that the pressure wave is controlled. The celerity, in its turn, is a function of the fluid characteristics, the network material and geometry. Provoking a change in the mean fluid compressibility there is a reduction in the volumetric compressibility coefficient and also in the specific mass of the mixture, which will cause a reduction in the speed of propagation of the wave or celerity, cushioning the impact of the pressure head variation to a level that can be absorbed by the installation. Therefore, the reduction in the speed of propagation or celerity canbe used is as a protection device for hydraulic nets, or celerity attenuation, which together with other devices, associated in series and distributed along the duct may absorb the excess of pressure and outflow generated by the transitory and keep the applied loading inferior to the resistance supplied by the installation.

La généralisation des mélangeurs continu dans l'industrie est freinée par le manque de connaissance générale sur ces procédés et en particulier d'une stratégie de contrôle commande de ce procédé. Se plaçant dans cette perspective, ce travail se penche, tant du point du vue expérimental et modélisation, sur la dynamique du procédé de mélange en continu, en particulier durant les phases transitoires que sont le démarrage, la vidange ou le changement de consigne. On étudie l'effet des variables opératoires, vitesse d'agitation et débit, sur la répartition massique et les débits internes des particules dans le mélangeur, ainsi que sur les variations d'homogénéité du mélange en sortie. A ce titre, un protocole expérimental spécifique basé sur l'analyse d'images est développé pour mesurer en ligne la qualité du mélange à une échelle d'observation que l'on peut ajuster. Un cadre de modélisation Markovienne est proposé pour décrire les phénomènes observés aux échelles macro et méso. Le modèle permet de décrire la composition du mélange dans les différentes zones du mélangeur ainsi qu'en sortie de l'appareil, quel que soit le régime envisagé, notamment lors de fortes perturbations de vitesse de rotation, dont l'intérêt est discuté. / The implementation of a continuous mixer in the industry requires detailed studies for a better understanding of this process, with essential aim the development of a control process strategy. The present work reports experimental and modelling results concerning the dynamics of a continuous powder mixer in steady and unsteady states. In particular, we will focus on the transitory phases that are likely to occur : starting, emptying, feeder's feeding, accidental perturbation, etc. We investigate the effect of operating variables, as rotational speed of the stirrer and the inflow rate, on the distribution of particles mass in the mixer and the intermediates flow rates, as well as that of the homogeneity of binary mixtures at the outlet of continuous mixer. A specific experimental protocol, based on image analysis, has been developed for determining mixture quality. The scale of scrutiny can be adjusted and mixture homogeneity can be calculated for this scale in real time. AMarkov chain model is proposed to describe the phenomena observed at both macro-and meso-scales. The model allows to describe the composition of the mixture in different zones of the mixer as well as in the outlet of the vessel, during steady and unsteady regimes and especially at high speed perturbations, whose interest is discussed.