The aim of this work was to develop a production process for the enzyme xyloglucan endo-transglycosylase from Populus tremula x tremuloides (PttXET16-34). The natural transglycosylating activity of this enzyme has previously been employed in a XET-Technology. This chemo enzymatic method is useful for biomimetic modification of cellulose surfaces and holds great potential for industrial applications. Thus, it requires that the XET-enzyme can be produced in larger scale. This work also shows how the wildtype PttXET16-34 was modified into a glycosynthase. By mutation of the catalytic nucleophile into an alanine, glycine or serine residue, enzymes capable of synthesising defined xyloglucan fragments were obtained. These defined compounds are very valuable for further detailed studies of xyloglucan active-enzymes, but are also useful in molecular studies of the structurally important xyloglucan-cellulose interaction. A heterologous production system for PttXET16-34 was previously developed in the methylotrophic yeast Pichia pastoris. A methanol-limited fed-batch process was also previously established, but the yield of active XET was low due to proteolysis problems and low productivity. Therefore, two alternative fed-batch techniques were investigated for the production of PttXET16-34: a temperature-limited fed-batch (TLFB) and an oxygen-limited high-pressure fed-batch (OLHPFB). For the initial recovery of XET after the fermentation process, two different downstream processes were investigated: expanded bed adsorption (EBA) and cross-flow filtration (CFF). / <p>QC 20101108</p>

The clown loach Chromobotia macracanthus, is a well known species in ornamental fish circuits although the knowledge about it in its wild environment today is limited. The outtake of 50 million juveniles every year may drive the population into a collapse and it might be necessary to breed clown loaches in captivity to lower the pressure in wild stocks. This has not yet been accomplished without hormone treatment. The aim of the present study is to find out if it is possible for C. macracanthus to prepare for spawning in captivity without the use of hormones. The study was set up according to documentation about the wild conditions simulating the migration prior to spawning from greater rivers and swamps to smaller streams upriver. Although the experiment did not result in spawning it is believed that egg production took place according to criteria for identifying sexually mature fish ready to spawn. If so it would have resulted in the fish retaining or reabsorbing the eggs since they were not laid. A surprising result which tells us it would not be unusual with egg production in C. macracanthus in aquariums around the world.

<p>Xyloglucans are polysaccharides found as storage polymers in seeds and tubers, and as cross-linking glycans in the cell wall of plants. Their structure is complex with intricate branching patterns, which contribute to the physical properties of the polysaccharide including its binding to and interaction with other glycans such as cellulose.</p><p>Xyloglucan is widely used in bulk quantities in the food, textile and paper making industries. With an increasing interest in technically more advanced applications of xyloglucan, such as novel biocomposites, there is a need to understand and control the properties and interactions of xyloglucan with other compounds, to decipher the relationship between xyloglucan structure and function, and in particular the effect of different branching patterns. However, due to the structural heterogeneity of the polysaccharide as obtained from natural sources, relevant studies have not been possible to perform in practise. This fact has stimulated an interest in synthetic methods to obtain xyloglucan mimics and analogs with well-defined structure and decoration patterns.</p><p>Glycosynthases are hydrolytically inactive mutant glycosidases that catalyse the formation of glycosidic linkages between glycosyl fluoride donors and glycoside acceptors. Since its first conception in 1998, the technology is emerging as a useful tool in the synthesis of large, complex polysaccharides. This thesis presents the generation and characterisation of glycosynthases based on xyloglucanase scaffolds for the synthesis of well-defined homogenous xyloglucan oligo- and polysaccharides with regular substitution patterns.</p>

Le thymus subit un vieillissement précoce, appelé involution thymique, qui cause une perte de fonction du thymus avec l’âge. À ce jour, les mécanismes de renouvellement des cellules épithéliales thymiques (TECs) sont encore mal compris, c’est pourquoi nous avons voulu identifier les cellules souches de l’épithélium thymique. Comme les cellules souches sont quiescentes dans plusieurs tissus, les objectifs de notre étude étaient de déterminer si l’épithélium thymique contenait des cellules quiescentes et d’étudier la cinétique de prolifération des TECs chez les souris jeunes et adultes. Pour ce faire, nous avons utilisé une souris transgénique (H2B-GFP Tet-On) nous permettant d’identifier les cellules ne se divisant pas sur une longue période de temps (LRC, label-retaining cells¬). Nous avons d’abord montré que les TECs proliféraient plus rapidement chez les femelles que les mâles. De plus, nous avons trouvé plusieurs différences entre l’épithélium thymique post-natal et adulte : (1) les TECs corticales (cTECs) et médullaires (mTECs) ont un taux de prolifération similaire chez les jeunes souris, mais chez l’adulte, les cTECs prolifèrent plus lentement que les mTECs; (2) les TECs prolifèrent plus rapidement chez les souris jeunes que adultes; (3) des LRC sont détectées chez l’adulte, mais pas chez les jeunes souris. Les LRC, retrouvées dans le compartiment cTEC, sous-expriment des gènes associés à la sénescence et surexpriment des gènes importants pour le développement et le renouvellement des TECs. Ces résultats montrent que ces cellules sont quiescentes et suggèrent qu’elles pourraient bel et bien être les progéniteurs thymiques responsables du renouvellement des TECs adultes. / The thymus undergoes a rapid degeneration with age termed thymic involution that causes a loss of function of the thymus with age. To this day, mechanisms of thymic maintenance are still unknown. This is why we aimed to identify thymic epithelial stem cells. Since stem cells are quiescent in many tissues in adults, our main objectives were to determine whether the thymic epithelium contains quiescent cells and study the proliferation kinetics of thymic epithelial cells in neonatal and adult mice. To this end, we used the transgenic mouse model H2B-GFP Tet-On, a label-retaining assay allowing us to identify cells that have not divided for a prolonged period of time, which are called label-retaining cells (LRC). First, we showed that in the adult thymus, females’ thymic epithelial cells (TECs) proliferated more actively than males’ TECs. We observed three main differences between neonatal and adult thymi: (1) cTECs and mTECs have similar proliferation rates in young, but mTECs cycled more actively in adult mice; (2) neonatal TECs have a higher turnover rate than adult’s TECs, and (3) we were able to detect LRC in adult mice, but not in neonatal mice. These LRC are contained in the cTEC compartment and express very low levels of senescence-associated proteins and show a high expression of genes important for thymic development and. These results show that the LRC identified in adult thymi are not senescent cells and therefore might represent the elusive thymic progenitor cells responsible for thymic maintenance and regeneration in adult mice.

Partout où la pierre est facilement disponible, on trouve des constructions en maçonnerie de pierre. Suivant les coutumes et les usages, les blocs de pierres sont assemblés bruts, simplement ébauchés ou parfaitement taillés, avec ou sans l'ajout d'un liant. Supplantée par le béton dans les constructions neuves depuis le milieu du XX} siècle, les ouvrages en maçonnerie demeurent majoritaires dans le patrimoine bâti français, un patrimoine qu'il convient d'entretenir rationnellement. L'objectif de ce travail de thèse est de poursuivre l'élaboration d'un cadre scientifique rigoureux et opérationnel afin de donner aux décideurs et aux gestionnaires les outils nécessaires pour mener à bien leur mission. Nous proposons ici deux outils d'évaluation de la stabilité d'ouvrages de soutènement en maçonnerie basés sur l'utilisation conjointe du calcul à la rupture avec des méthodes d'homogénéisation. Dans un premier temps, nous mettons d'abord au point un outil analytique permettant de dimensionner des ouvrages neufs ou d'évaluer la stabilité d'ouvrages peu déformés. Cet outil permet également de dimensionner des solutions de renforcement par clouage lorsque cela est jugé nécessaire. Dans un deuxième temps, nous implémentons cet outil dans un code numérique afin de lui donner la souplesse nécessaire à l'étude d'ouvrages non-conventionnels, de grandes taille ou fortement pathologique. Enfin, nous mettons en oeuvre plusieurs campagnes expérimentales qui nous fournissent les données nécessaires à la validation de ces modèles de calcul / Wherever stone is readily available, we encounter stone masonry buildings. Depending on customs or dedicated use, the blocks are used raw, lightly faced or perfectly cut, with or without the use of mortar. Althougth concrete has replaced masonry in new construction for some decades, the better part of the French built heritage is made of masonry, an heritage we are responsible for. This works aims at contributing to create a reliable scientific frame for that purpose. This thesis uses the yield design theory alongside with homogenisation techniques to study the stability of stone masonry earth retaining walls. First, we provide an analytical tool suitable for designing new structures or assessing the stability of existing ones that are still in good shape. Should it be needed, this tools allows for the design of a strengthening solution based on soil-nailing. Then, we implement it in a finite element code to give it the versatility required to study unconventionnal structures or structures badly damaged. We then present several experimental campaigns aiming at validating the proposed tools

A numerical investigation was conducted to evaluate the geotechnical safety and slope stability of Municipal Solid Waste (MSW) landfills, considering the effects of geosynthetic reinforcements, biodegradation of the waste, and associated changes in material properties, and extreme wind force simulating hurricane conditions. Three different landfill slopes, 1:1, 1:2, and 1:3 having the height of 122m and width of 2134m, were analyzed using Limit Equilibrium Method (SLOPE/W) and Finite Element Modeling (ANSYS). Techniques developed in this study were used to analyze a case history involving a geogrid reinforced mixed landfill expansion located in Austria. It was found that few years after construction of the landfill, there is a significant decrease in the FS due to biodegradation. Extreme wind loading was also found to cause a substantial loss in the FS. The geosynthetic reinforcement increased the slope stability and approximately compensated for the damaging effects of biodegradation and wind loading. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Made available in DSpace on 2016-04-04T18:21:34Z (GMT). No. of bitstreams: 1 Paulo Martins 1.pdf: 23811071 bytes, checksum: 568400fecf0be29d976bf705b868b9c3 (MD5) Previous issue date: 2006-11-07 / Pontif?cia Universidade Cat?lica de Campinas / In the rainy periods, the city of S?o Paulo becomes a scenario for constant social and economical impacts before the damages caused by the inundations. This fact is associated, among other reasons, to an expressive land occupation and soil water-sealing and to the occupation of the areas under risk of inundations the meadows and bottoms of valleys. The research below analyzes the different concepts for handling pluvial waters under the scope of reflections relative to the infrastructure works and public actions addressed to prevent inundations. We tried to present the hygienist vision regarding the increase in water conductivity up to the new environmental vision of sustainable rain water handling, highlighting the use of non-structural measures. For such an effect, we used as case study the Basin of C?rrego Cabu?u de Baixo located at the northwest area of the city of S?o Paulo that, for a long time, was object for punctual interventions with predominance of canalization works and, in the end of the nineties, it counted with the implementation of non-conventional measures that took into account the planning of land occupation and the reservation of pluvial waters. Through the evaluation of this experience we look for identifying the permanencies and ruptures in the treatment related to the subject of inundations. / Nos per?odos de precipita??es, a cidade de S?o Paulo torna-se cen?rio de constantes impactos sociais e econ?micos frente aos preju?zos causados pelas inunda??es. Esse fato est? associado, entre outros motivos, a uma expressiva ocupa??o e impermeabiliza??o do solo e ? ocupa??o das ?reas de risco de enchentes as v?rzeas e fundos de vales. A pesquisa que se segue analisa as diversas concep??es de manejo de ?guas pluviais no ?mbito das reflex?es relativas ?s obras de infra-estrutura e a??es p?blicas destinadas ? preven??o de enchentes. Buscou-se apresentar desde a vis?o higienista do aumento da condutividade hidr?ulica at? a nova vis?o ambiental do manejo sustent?vel da ?gua precipitada, com ?nfase no uso de medidas n?o-estruturais. Nesse sentido, foi utilizado como estudo de caso a Bacia do C?rrego Cabu?u de Baixo localizada na regi?o noroeste da cidade de S?o Paulo que, durante muito tempo, foi objeto de interven??es pontuais com predomin?ncia de obras de canaliza??o e, no final dos anos 90, contou com a implementa??o de medidas n?o convencionais que levaram em considera??o o planejamento da ocupa??o do solo e a reserva??o das ?guas pluviais. Atrav?s da avalia??o dessa experi?ncia busca-se identificar as perman?ncias e rupturas no trato com a quest?o das enchentes.

Submitted by Joana Azevedo (joanad@id.uff.br) on 2017-08-15T19:32:52Z No. of bitstreams: 1 Dissert Wagner de Araujo Rezende.pdf: 2213131 bytes, checksum: 53828137b30488961115861329f87b2f (MD5) / Approved for entry into archive by Biblioteca da Escola de Engenharia (bee@ndc.uff.br) on 2017-09-05T13:17:53Z (GMT) No. of bitstreams: 1 Dissert Wagner de Araujo Rezende.pdf: 2213131 bytes, checksum: 53828137b30488961115861329f87b2f (MD5) / Made available in DSpace on 2017-09-05T13:17:53Z (GMT). No. of bitstreams: 1 Dissert Wagner de Araujo Rezende.pdf: 2213131 bytes, checksum: 53828137b30488961115861329f87b2f (MD5) Previous issue date: 2016-11-29 / Esta dissertação aborda o comprometimento organizacional em um contexto de crise econômica atravessada no Brasil. Buscou-se compreender quais os padrões de comprometimento e níveis de engajamento apresentam os funcionários de uma empresa em situações de incerteza da manutenção dos próprios vínculos empregatícios em função das mudanças estruturais e de redução do quadro de pessoal realizadas, internamente, como decorrência do contexto econômico externo. A pesquisa é caracterizada como um estudo de caso em uma empresa de varejo de grande porte com sede no Estado do Rio de Janeiro, objetivando compreender o reconhecimento da instabilidade econômica vivida pelo país; os reflexos dela sobre as organizações e ameaça aos contratos de trabalho; e, em relação a essa controvérsia, busca compreender como estão comprometidos seus empregados na visão dos gestores perante a perspectiva de superação do momento e com os objetivos de negócio. Também foi possível mapear os fatores de retenção profissional mesmo em ambientes complexos e o tipo de comprometimento que se destaca nessas circunstâncias. Quanto ao meio de investigação, além da pesquisa bibliográfica e documental, foi realizada uma pesquisa de campo, baseada na metodologia do estudo de caso único. Em loco foi possível compreender as ações de engajamento realizadas pela organização estudada, os resultados da pesquisa de engajamento realizada com todos os funcionários e, também, foram realizadas entrevistas com executivos numa amostra de dez gestores das áreas de backoffice e da atividade fim, operações de loja. As respostas foram analisadas qualitativamente, sendo criados distintos sistemas de categorização do conteúdo das informações. Os principais resultados demonstraram o reconhecimento dos executivos quanto ao momento de crise econômica vivido pelo país e o quanto esse contexto impacta nas ações de redução de despesas por parte da empresa; a percepção destes acerca do comprometimento de suas equipes; o que o atual momento exigiu dos gestores e os fatores que os levam a permanecerem comprometidos na organização mesmo em momentos de instabilidade. / This dissertation talks about the organizational commitment in a context of economics crisis in course in Brazil. Tring to understand what kind of standard commitment and engagement levels are demonstrated by employees of a company in uncertain situations including the maintenance of their employment contract due to the structure changes and downsizing actions implemented internally due to the external economic context. The research considered a case of study in a big size retail company with it’s headquarter in Rio de Janeiro State aiming to understand if they realize the economic instability current in place in the country and reflected as a threat to their labor contracts. In this way understand how committed are the employees in surpass this moment and how committed they are with the business. Was also possible assess the retaining professional factors even though complex circumstances and the type of commitment most evident in this kind of circumstance. Regarding the investigation methods in additional to the bibliographic and documental research a survey in the field based in the unique case of study was implemented. Was possible to understand in locus the engagement actions implemented by the studied organization, the results of the engagement survey administrated to all employees and was also implemented interviews with ten executives of the backoffice and operations departments. The answers were qualitative analyzed and different categories were created of the contents information. The main results showed the awareness of the executives regarding the current moment of economics crisis faced by the country and how this context impacts in actions of cost reduction by the company; their perception about their team commitment; what this moment required about themselves; and the retaining factors that make themselves committed with the organization even in instable circumstance.

This thesis presents the application of different protein engineering methods on enzymes and non-catalytic proteins that act upon xyloglucans. Xyloglucans are polysaccharides found as storage polymers in seeds and tubers, and as cross-linking glucans in the cell wall of plants. Their structure is complex with intricate branching patterns, which contribute to the physical properties of the polysaccharide including its binding to and interaction with other glucans such as cellulose. One important group of xyloglucan-active enzymes is encoded by the GH16 XTH gene family in plants, including xyloglucan endo-transglycosylases (XET) and xyloglucan endo-hydrolases (XEH). The molecular determinants behind the different catalytic routes of these homologous enzymes are still not fully understood. By combining structural data and molecular dynamics (MD) simulations, interesting facts were revealed about enzyme-substrate interaction. Furthermore, a pilot study was performed using structure-guided recombination to generate a restricted library of XET/XEH chimeras. Glycosynthases are hydrolytically inactive mutant glycoside hydrolases (GH) that catalyse the formation of glycosidic linkages between glycosyl fluoride donors and glycoside acceptors. Different enzymes with xyloglucan hydrolase activity were engineered into glycosynthases, and characterised as tools for the synthesis of well-defined homogenous xyloglucan oligo- and polysaccharides with regular substitution patterns. Carbohydrate-binding modules (CBM) are non-catalytic protein domains that bind to polysaccharidic substrates. An important technical application involves their use as molecular probes to detect and localise specific carbohydrates in vivo. The three-dimensional structure of an evolved xyloglucan binding module (XGBM) was solved by X-ray diffraction. Affinity-guided directed evolution of this first generation XGBM resulted in highly specific probes that were used to localise non-fucosylated xyloglucans in plant tissue sections. / QC 20100902

Solid concrete Lego blocks can be used as temporary retaining wall systems or as wall separators between different materials such as sand, salt, compost, etc. The advantage of concrete blocks is that you can create temporary constructions. It is easy to move or expand the constructions when no casting is required between the blocks. The purpose of this study is to make models in the Finite Element (FE) software Abaqus/CAE that can be used for calculations of the capacity for interlocking blocks. FE method is an approximate method for solving differential equations. As the concrete blocks are stacked without casting, it is important to find out the construction’s load capacity when it is subjected to a horizontal load. Several types of structures have been modeled in the FE program Abaqus/CAE. These FE models were created with boundary conditions consisting of springs and a pinned connection that allows rotation.The evaluation has been focused on rotating the interlocking blocks. With the help of the FE models, reaction forces have been calculated. The FE results in term of reaction forces have been compared with hand calculations made ​​for the same models. Moreover, a wall and a wall with lateral supports have been simulated to determine the horizontal reaction force for the interlocking concrete blocks. / Massiva Lego betongblock kan ändvänds som tillfälliga stödmurar eller vägg avskiljare för olika material som salt, kompost, sand mm. Fördelen med betongblocken är att man kan skapa tillfälliga konstruktioner. Det är lätt att flytta eller bygga ut konstruktionen när ingen fog krävs mellan blocken. Syftet med denna studie är att skapa modeller i Finita Element (FE) programmet Abaqus/CAE som kan senare användas för beräkning av kapaciteten för sammankopplade block. FE Metoden är en approximativ metod för att lösa differential ekvationer. Eftersom betongblocken är staplade på varandra utan fog är det viktigt att ta reda på konstruktionens lastupptagnings förmåga när den är belastade med horisontalkrafter. Flera typer av konstruktioner har modellerats i FE programmet Abaqus/CAE. Dessa FE modeller har skapats med randvillkor som består av fjädrar och fasta lager som tillåter rotation. Utvärderingen har gjorts med fokus på vältningen i betongblocken. Med hjälp av dessa FE modeller har reaktionskraften tagits fram. FE resultaten i form av reaktionskrafter har sedan jämförts med handberäkningar gjorda för samma modeller. Vidare har en vägg och en vägg med sidostöd FE modellerats för att utvärdera horisontala deformationsegenskaper. / - / -