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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
431

Analysis of the barley (Hordeum vulgare) tightly bound DNA-protein complexes / Miežių (Hordeum vulgare) tvirtų DNR-baltymų kompleksų analizė

Bielskienė, Kristina 02 December 2009 (has links)
Despite a great deal of research, the functional significance of tightly bound DNA-protein complexes is not yet clear, therefore these complexes are perfect object for pioneering research. Very little is known about plant TBP-DNA complexes. In this work we investigated barley TBP-DNA complexes from different organs (first leaves, roots and coleoptiles) at different developmental stages. We characterized individual components of tightly bound DNA-proteins complexes: polypeptides (TBP) and DNA. We isolated and characterized TBP proteins from barley first leaves, roots and coleoptiles of different age and differentiation stage. Also we isolated and characterized the DNA fragments from barley first leaves and water ripe and milky ripe grain TBP-DNA complexes. We demonstrated that in different developmental stages of coleoptiles, first leaves and roots TBP-DNA complexes were identified as a group of 15-160 kDa proteins, most of TBPs are acidic. Some of barley TBPs (10, 25, 38, 40 and 55 kDa) exhibit phosphatase, maybe Ser/Thr activity. We have identified also that some of TBPs tyrosines were phosphorylated, this modification depends on organ and developmental stage. Identified barley TBPs were involved in fundamental genetic processes, as well as in chromatin rearrangement and regulation processes. Nuclear matrix proteins, enzymes, transcription factors, serpins, immunophilins, and transposon polypeptides were identified among TBPs. We demonstrated that expression of TBPs depends... [to full text] / Žinoma, kad pastovi nehistoninių polipetidų frakcija yra išgryninama kartu su eukariotine DNR ir sudaro labai tvirtus (galbūt kovalentinius) kompleksus tarp branduolio baltymų ir DNR. Nustatyta, kad Erlicho ascito tvirtuose DNR-baltymų kompleksuose yra baltymas C1D, baltymai, pasižymintys fosfataziniu ir kinaziniu aktyvumais, kai kurie proteazių slopikliai ir kiti, dar neištirti baltymai. Nepaisant intensyvių tyrinėjimų, eukariotinių ląstelių tvirti DNR-baltymų kompleksai vis dar lieka menkai aprašyti ir yra objektas tolimesniems tyrimams. Augalų TBP-DNR kompleksai kol kas buvo tyrinėti labai mažai. Šiame darbe charakterizuojami miežių Hordeum vulgare tvirti DNR-baltymų kompleksai. Mes tyrėme TBP-DNR kompleksus iš miežių skirtingų ūglių organų ir skirtingų vystymosi stadijų ląstelių: lapų, šaknų, koleoptilės. Norint ištirti tokių nukleoproteidų funkcijas, svarbu charakterizuoti individualius komplekso komponentus: polipeptidus ir DNR. Taigi, išskyrėme tvirtai su DNR sąveikaujančius baltymus iš miežių skirtingos diferenciacijos bei skirtingo amžiaus ląstelių: pirminių lapelių, šaknų, koleoptilės ir juos charakterizavome. Taip pat išskyrėme ir charakterizavome DNR fragmentus iš miežių pirminių lapelių bei vandeninės brandos ir pieninės brandos grūdų TBP-DNR kompleksų. Parodėme, kad miežių TBP baltymai yra 15-160 kDa, dauguma baltymų yra rūgštiniai. Kai kurie iš miežių TBP baltymų (10, 25, 38, 40 ir 55 kDa) pasižymi fosfataziniu, galbūt, Ser/Thr aktyvumu. Nustatėme, kad tam... [toliau žr. visą tekstą]
432

Miežių (Hordeum vulgare) tvirtų DNR-baltymų kompleksų tyrimas / Analysis of the barley (Hordeum vulgare)tightly bound DNA-protein complexes

Bielskienė, Kristina 02 December 2009 (has links)
Žinoma, kad pastovi nehistoninių polipetidų frakcija yra išgryninama kartu su eukariotine DNR ir sudaro labai tvirtus (galbūt kovalentinius) kompleksus tarp branduolio baltymų ir DNR. Nustatyta, kad Erlicho ascito tvirtuose DNR-baltymų kompleksuose yra baltymas C1D, baltymai, pasižymintys fosfataziniu ir kinaziniu aktyvumais, kai kurie proteazių slopikliai ir kiti, dar neištirti baltymai. Nepaisant intensyvių tyrinėjimų, eukariotinių ląstelių tvirti DNR-baltymų kompleksai vis dar lieka menkai aprašyti ir yra objektas tolimesniems tyrimams. Augalų TBP-DNR kompleksai kol kas buvo tyrinėti labai mažai. Šiame darbe charakterizuojami miežių Hordeum vulgare tvirti DNR-baltymų kompleksai. Mes tyrėme TBP-DNR kompleksus iš miežių skirtingų ūglių organų ir skirtingų vystymosi stadijų ląstelių: lapų, šaknų, koleoptilės. Norint ištirti tokių nukleoproteidų funkcijas, svarbu charakterizuoti individualius komplekso komponentus: polipeptidus ir DNR. Taigi, išskyrėme tvirtai su DNR sąveikaujančius baltymus iš miežių skirtingos diferenciacijos bei skirtingo amžiaus ląstelių: pirminių lapelių, šaknų, koleoptilės ir juos charakterizavome. Taip pat išskyrėme ir charakterizavome DNR fragmentus iš miežių pirminių lapelių bei vandeninės brandos ir pieninės brandos grūdų TBP-DNR kompleksų. Parodėme, kad miežių TBP baltymai yra 15-160 kDa, dauguma baltymų yra rūgštiniai. Kai kurie iš miežių TBP baltymų (10, 25, 38, 40 ir 55 kDa) pasižymi fosfataziniu, galbūt, Ser/Thr aktyvumu. Nustatėme, kad tam... [toliau žr. visą tekstą] / Despite a great deal of research, the functional significance of tightly bound DNA-protein complexes is not yet clear, therefore these complexes are perfect object for pioneering research. Very little is known about plant TBP-DNA complexes. In this work we investigated barley TBP-DNA complexes from different organs (first leaves, roots and coleoptiles) at different developmental stages. We characterized individual components of tightly bound DNA-proteins complexes: polypeptides (TBP) and DNA. We isolated and characterized TBP proteins from barley first leaves, roots and coleoptiles of different age and differentiation stage. Also we isolated and characterized the DNA fragments from barley first leaves and water ripe and milky ripe grain TBP-DNA complexes. We demonstrated that in different developmental stages of coleoptiles, first leaves and roots TBP-DNA complexes were identified as a group of 15-160 kDa proteins, most of TBPs are acidic. Some of barley TBPs (10, 25, 38, 40 and 55 kDa) exhibit phosphatase, maybe Ser/Thr activity. We have identified also that some of TBPs tyrosines were phosphorylated, this modification depends on organ and developmental stage. Identified barley TBPs were involved in fundamental genetic processes, as well as in chromatin rearrangement and regulation processes. Nuclear matrix proteins, enzymes, transcription factors, serpins, immunophilins, and transposon polypeptides were identified among TBPs. We demonstrated that expression of TBPs depends... [to full text]
433

Eager, Lazy, and Other Executions for Predicative Programming

Lai, Yu Cheong Albert 08 August 2013 (has links)
Many programs are executed according to the conventional, eager execution order, for which verification of execution costs is well-understood. However, there are other execution orders in use. One such order in common use is lazy execution or lazy evaluation, which is mostly demand-driven. Laziness supports better decompositions of algorithms, e.g., into modular producers and consumers, which enables compositional reasoning of answer correctness, but then timing correctness is more elusive. This thesis gives a formal method for verifying lazy timing, compositional with respect to program structure; it is an extension of a predicative programming theory. Predicative programming theories are formal methods that unify both specifications and programs as predicates or boolean-typed expressions over memory state and other quantities of interest. Their strengths are mathematical simplicity and support of program development and verification by incremental refinements. Among these theories, Hehner's a Practical Theory of Programming has the further strength of leaving termination and timing open rather than a built-in, and therefore is a flexible substrate for various timing schemes corresponding to various execution strategies. We use this substrate for our method for lazy timing. This thesis also proves soundness of the eager timing scheme in Hehner's work with respect to an eager operational semantics, and our lazy timing scheme with respect to a lazy operational semantics. Thus, if refinements promise an upper time bound, then execution actually stops within that time. Lastly, this thesis outlines a space of more operational semantics. It is possible ground for more execution strategies.
434

Eager, Lazy, and Other Executions for Predicative Programming

Lai, Yu Cheong Albert 08 August 2013 (has links)
Many programs are executed according to the conventional, eager execution order, for which verification of execution costs is well-understood. However, there are other execution orders in use. One such order in common use is lazy execution or lazy evaluation, which is mostly demand-driven. Laziness supports better decompositions of algorithms, e.g., into modular producers and consumers, which enables compositional reasoning of answer correctness, but then timing correctness is more elusive. This thesis gives a formal method for verifying lazy timing, compositional with respect to program structure; it is an extension of a predicative programming theory. Predicative programming theories are formal methods that unify both specifications and programs as predicates or boolean-typed expressions over memory state and other quantities of interest. Their strengths are mathematical simplicity and support of program development and verification by incremental refinements. Among these theories, Hehner's a Practical Theory of Programming has the further strength of leaving termination and timing open rather than a built-in, and therefore is a flexible substrate for various timing schemes corresponding to various execution strategies. We use this substrate for our method for lazy timing. This thesis also proves soundness of the eager timing scheme in Hehner's work with respect to an eager operational semantics, and our lazy timing scheme with respect to a lazy operational semantics. Thus, if refinements promise an upper time bound, then execution actually stops within that time. Lastly, this thesis outlines a space of more operational semantics. It is possible ground for more execution strategies.
435

Approximation Algorithms for Network Connectivity Problems

Cameron, Amy 18 April 2012 (has links)
In this dissertation, we examine specific network connectivity problems, and achieve improved approximation algorithm and integrality gap results for them. We introduce an important new, highly useful and applicable, network connectivity problem - the Vital Core Connectivity Problem (VCC). Despite its many practical uses, this problem has not been previously studied. We present the first constant factor approximation algorithm for VCC, and provide an upper bound on the integrality gap of its linear programming relaxation. We also introduce a new, useful, extension of the minimum spanning tree problem, called the Extended Minimum Spanning Tree Problem (EMST), that is based on a special case of VCC; and provide both a polynomial-time algorithm and a complete linear description for it. Furthermore, we show how to generalize this new problem to handle numerous disjoint vital cores, providing the first complete linear description of, and polynomial-time algorithm for, the generalized problem. We examine the Survivable Network Design Problem (SNDP) with multiple copies of edges allowed in the solution (multi-SNDP), and present a new approximation algorithm for which the approximation guarantee is better than that of the current best known for certain cases of multi-SNDP. With our method, we also obtain improved bounds on the integrality gap of the linear programming relaxation of the problem. Furthermore, we show the application of these results to variations of SNDP. We investigate cases where the optimal values of multi-SNDP and SNDP are equal; and we present an improvement on the previously best known integrality gap bound and approximation guarantee for the special case of SNDP with metric costs and low vertex connectivity requirements, as well as for the similar special case of the Vertex Connected Survivable Network Design Problem (VC-SNDP). The quality of the results that one can obtain for a given network design problem often depends on its integer linear programming formulation, and, in particular, on its linear programming relaxation. In this connection, we investigate formulations for the Steiner Tree Problem (ST). We propose two new formulations for ST, and investigate their strength in terms of their associated integrality gaps.
436

Assembly Line Balancing With Task Paralleling

Kaplan, Ozlem 01 September 2003 (has links) (PDF)
In this study, we consider single model deterministic Assembly Line Balancing problem with task paralleling. The objective is to minimize the total cost which is composed of station opening cost and task dependent equipment cost. A branch and bound algorithm that allows two-level task paralleling is proposed. A heuristic algorithm is also developed both for obtaining efficient upper bounds to branch and bound and for achieving good approximate solutions for large sized problems. Computational experiments are conducted to investigate the effects of experimental parameters on the cost-related and algorithm-related performance measures. The exact algorithm results are compared to the proposed heuristic algorithm results, station paralleling results and optimal solutions without paralleling.
437

Tourenplanung mittelständischer Speditionsunternehmen : Modelle und Methoden /

Rieck, Julia. January 2008 (has links)
Zugl.: Clausthal, Techn. Universiẗat, Diss., 2008.
438

Θεωρία χορδών και φυσικές εφαρμογές αυτής σε προβλήματα βαρύτητας και θεωρίας βαθμίδας

Σιάμπος, Κωνσταντίνος 05 January 2011 (has links)
Σε αυτή την διδακτορική διατριβή μελετήσαμε την ευστάθεια δέσμιων καταστάσεων κουάρκ και δυονίων εντός της αντιστοιχίας AdS/CFT. Το κίνητρο για την μελέτη μας ήταν το ότι τα δυναμικά των δέσμιων αυτών καταστάσεων όπως αυτά υπολογίζονται εντός της αντιστοιχίας έχουν μερικές φορές συμπεριφορές οι οποίες είναι σε αντίθεση με τα προσδοκώμενα αποτελέσματα από την θεωρία πεδίου. Συγκεκριμένα συναντούμε: Πλειότιμα δυναμικά, Δυναμικά του οποίου το μήκος θωράκισης εξαρτάται ισχυρώς από τον προσανατολισμό της χορδής σε σχέση με τον άξονα του ζεύγους και Συμπεριφορές εγκλωβισμού κουάρκ στην N=4 SYM και διάφορες άλλες περιπτώσεις. Η ανάλυση της ευστάθειας των κλασσικών λύσεων επιλύει αυτές τις αντιφάσεις, αποδεικνύοντας ότι οι αυτές οι διατάξεις είναι ασταθείς και κατά συνέπεια είναι φυσικώς απαράδεκτες. / In this PhD thesis we studied the stabilty of quarks and dyons bound states within the AdS/CFT Correspondence. The motivation for our study was the fact that bound states potentials as these are calculated within AdS/CFT have in various cases behaviors which contradict the field theory expectations. In particular we find: Multivalued potentials, Potentials whose scrrening length heavily depends on the orientation of the string and quark confinment in N=4 SYM. Stability analysis of the classical solutions resolves these ambiguities between field theory expectations and their dual gravity description, proving that these configurations are unstable and thus they should be disgarded as unphysical.
439

Bornes supérieures pour les valeurs propres d'opérateurs naturels sur les variétés riemanniennes compactes / Upper bounds for the eigenvalues of natural operators on compact Riemannian manifolds

Hassannezhad, Asma 14 June 2012 (has links)
Le but de cette thèse est de trouver des bornes supérieures pour les valeurs propres des opérateurs naturels agissant sur les fonctions d’une variété compacte (M; g). Nous étudions l’opérateur de Laplace–Beltrami et des opérateurs du type laplacien. Dans le cas du laplacien, deux aspects sont étudiés. Le premier aspect est d’étudier des relations entre la géométrie intrinsèque et les valeurs propres du laplacien. Nous obtenons des bornes supérieures ne dépendant que de la dimension et d’un invariant conforme qui s’appelle le volume conforme minimal. Asymptotiquement, ces bornes sont consistantes avec la loi de Weyl. Elles améliorent également les résultats de Korevaar et de Yang et Yau. La méthode employée est intéressante en soi. Le deuxième aspect est d’étudier la relation entre la géométrie extrinsèque et les valeurs propres du laplacien agissant sur des sous-variétés compactes de RN et de CPN. Nous étudions un invariant extrinsèque qui s’appele l’indice d’intersection. Pour des sous-variétés compactes de RN, nous généralisons les résultats de Colbois, Dryden et El Soufi et obtenons des bornes supérieures qui sont stables par des petites perturbations. Pour des sous-variétés de CPN, nous obtenons une borne supérieure ne dépendant que du degré des sous-variétés. Pour des opérateur du type laplacien, une modification de notre méthode donne des bornes supérieures pour les valeurs propres des opérateurs de Schrödinger en termes du volume conforme minimal et de l’intégrale du potentiel. Nous obtenons également les bornes supérieures pour les valeurs propres du laplacien de Bakry–Émery dépendant d’invariants conformes. / The purpose of this thesis is to find upper bounds for the eigenvalues of natural operators acting on functions on a compact Riemannian manifold (M; g) such as the Laplace–Beltrami operator and Laplace-type operators. In the case of the Laplace-Beltrami operator, two aspects are investigated: The first aspect is to study relationships between the intrinsic geometry and eigenvalues of the Laplacian operator. In this regard, we obtain upper bounds depending only on the dimension and a conformal invariant called min-conformal volume. Asymptotically, these bounds are consistent with the Weyl law. They improve previous results by Korevaar and Yang and Yau. The method which is introduced to obtain the results, is powerful and interesting in itself. The second aspect is to study the interplay of the extrinsic geometry and eigenvalues of the Laplace–Beltrami operator acting on compact submanifolds of RN and of CPN. We investigate an extrinsic invariant called the intersection index studied by Colbois, Dryden and El Soufi. For compact submanifolds of RN, we extend their results and obtain upper bounds which are stable under small perturbation. For compact submanifolds of CPN, we obtain an upper bound depending only on the degree of submanifolds. For Laplace type operators, a modification of our method lead to have upper bounds for the eigenvalues of Schrödinger operators in terms of the min-conformal volume and integral quantity of the potential. As another application of our method, we obtain upper bounds for the eigenvalues of the Bakry–Émery Laplace operator depending on conformal invariants.
440

Barreiras, fronteiras e passagens : a burocracia e o laço social na saúde mental pública brasileira : travessia de uma experiência

Veronese, Luciane Gheller January 2015 (has links)
A pesquisa apresenta reflexões e experiências a partir dos fenômenos socioculturais e políticos, no campo da saúde mental pública brasileira, através das articulações entre o sujeito e a cultura. Estuda a temática da burocracia, pensada como política da indiferença a partir da metáfora da máquina e do anonimato como referentes do laço social neste discurso. Enfatiza as formas burocráticas contemporâneas, típicas dos Estados capitalistas atuais, os traços de uma burocracia à brasileira, estabelecida pelo hibridismo entre a autoritária maneira de lidar com a norma e seus matizes flexíveis, além das raízes da burocracia missioneira. Discute as transformações do modelo de saúde mental, com seus avanços e retrocessos, problematizando as dificuldades de rupturas com o modelo manicomial. Discorre acerca da configuração da política sanitária brasileira, com destaque para a saúde mental, em especial os CAPS. Através de fragmentos de experiências em um CAPSi propõe o lugar destas instituições como lugares utópicos, de passagens, “lugar Entre”. Aponta para a necessidade de profanar a burocracia, atentando aos restos não burocratizáveis, a partir de dois eixos: o brincar como dispositivo fundamental do trabalho em um CAPSi e a produção/utilização do arquivo como testemunha na instituição de saúde mental pública, reconhecendo a importância de um trabalho singularizado, artesanal, que não suspenda a capacidade de pensar e fortaleça o espaço público. / This research presents reflections and experiences on sociocultural and political phenomenon in the Brazilian public mental health field, articulating the subject and the culture. It studies the bureaucracy considered as an indifference policy through the machine metaphor and the anonymity as referential of the social bond in this speech. It also emphasizes the contemporary bureaucratic characteristics, typical from modern capitalist States, the features of a Brazilian bureaucracy, stablished by the hybridism between the authoritarian way of dealing with the norm and its flexible nuances, besides the roots of a missioneira bureaucracy. It argues the mental health model transformations, focusing its advances and retrocessions, as well as it analyzes the difficulties of rupture with the asylum model. It debates about the Brazilian sanitary policy, emphasizing the mental health, especially the CAPS. Thus, through experiences at a CAPSi, it proposes the place of these institutions as utopic places, of passage, “in-between place”. It points out the necessity to desecrate the bureaucracy, giving attention to the non-bureaucratic parts through two axis: to play as a fundamental device of work at a CAPSi and the production/use of a file as a witness in a public mental health institution, recognizing the importance of a singularized word, handmade, which does not suspend the ability to think and fortifies the public space.

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