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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.
121

MSB First Arithmetic Circuit for Motion Estimation

Bashir, Zeeshan Ahmed 01 August 2015 (has links)
AN ABSTRACT OF THE THESIS OF Zeeshan Ahmed Bashir, for the Masters of Science degree in Electrical and Computer Engineering, presented on 29th June 2015, at Southern Illinois University Carbondale TITLE: MSB FIRST ARITHMETIC CIRCUIT FOR MOTION ESTIMATION MAJOR PROFESSOR: Dr. Haibo Wang This thesis presents a novel design of arithmetic circuits that perform computation from MSB to LSB in a serial manner. In the MSB first serial computation, the result is gradually refined along the computation cycles. If the result is used to do a comparison with a threshold, such as in motion estimation applications, it is possible to draw the comparison conclusion in the middle of the computation and subsequently skip the rest of the computation. Thus the MSB-first serial computation potentially results in significant power reduction, making them attractive to low power applications. Unlike the existing MSB-first design that uses redundant number system, the proposed design is based on the widely used 2’ complementary number system, making the proposed circuits more compact and consuming less power as compared to the existing circuits that use signed digital bit numbers. The proposed arithmetic circuits have been used to implement variable block size motion estimation (VBSME) circuits, including block sizes of 4x4, 8x4, 8x8, 8x16 and 16x16 on a Xilinx Spartan 6 FPGA device. The performance of the proposed design is compared with the design based on existing MSB-first arithmetic circuit. The comparison shows the proposed design consumes significantly less power compared to the reference design.
122

Avaliação do efeito de contraceptivos hormonais sobre o sistema complemento / Evaluation of the effect of hormonal contraceptives on the complement system

Renata Ignácio Bertozi 29 April 2011 (has links)
A ocorrência de trombose está freqüentemente associada com a presença de um ou mais fatores de riscos, os quais podem ser genéticos e/ou adquiridos, tais como as mudanças hormonais que ocorrem durante a gravidez, a terapia de reposição hormonal e o uso de contraceptivos hormonais combinados (CHC). A inflamação, por sua vez, é uma importante resposta do organismo às agressões e envolve vários mecanismos biológicos relacionados entre si e altamente regulados, tais como: coagulação, fibrinólise, ativação do sistema complemento (SC), antioxidação e regulação hormonal. Fisiologicamente, os sistemas complemento e da coagulação compartilham componentes. A ativação do fator XII da coagulação é controlada pela mesma proteína reguladora da ativação do sistema complemento, o inibidor de C1. A deficiência do inibidor de C1 leva a uma patologia conhecida como angioedema hereditário. No entanto, uma manifestação clínica similar ao angioedema tem sido descrita em mulheres que usam CHC ou recebem terapia de reposição hormonal com estrogênio (E). Esta influência do estrogênio na coagulação e no SC também é evidenciada pela ação regulatória do E sobre a expressão do fator XII e dos seus níveis plasmáticos. Considerando o efeito pleiotrópico do E, e as interações do SC e da hemostasia, o objetivo desse estudo foi avaliar o efeito de diferentes CHC sobre: a) a atividade hemolítica (AH) do SC e ativação das vias clássica/lectina e alternativa; b) a atividade opsonizante do SC em mediar o burst oxidativo dos neutrófilos; e c) a função dos receptores para complemento (CR) em mediar o burst oxidativo dos neutrófilos. Nós estudamos 5 CHC diferentes e observamos que a) drospirenona + 30g E mostrou uma tendência a aumentar o burst oxidativo mediado por CR; b) gestodeno + 20g E mostrou redução da capacidade opsonizante do SC; c) levonorgestrel + 30g E e gestodeno + 20g E promoveram uma redução no número de neutrófilos positivos para a expressão de CR1; d) drospirenona + 30g E e drospirenona + 20g E promoveram um aumento da AH da via clássica (VC) do SC; e) levonorgestrel + 30g E promoveu uma redução da AH da VC do SC; f) drospirenona + 30g E, gestodeno + 20g E e levonorgestrel + 30g E promoveram uma diminuição do nível sérico de C4d, produto da ativação das vias clássica/lectina do SC; g) levonorgestrel + 30g E apresentou um aumento da concentração sérica de inibidor de C1; h) nenhum dos CHC mostrou diferenças na ativação da via alternativa do SC. Os resultados mostram a importância de considerar os diferentes grupos de CHC nas comparações com o Grupo Controle, uma vez que algumas diferenças foram significativas apenas para CHC em particular. Estas observações podem contribuir para o entendimento dos mecanismos envolvidos na fisiopatologia dos processos inflamatórios associados ao uso de estrogênios. / The occurrence of thrombosis is often associated with the presence of one or more risk factors, which may be genetic and/or acquired, such as hormonal changes that occur during pregnancy, hormone replacement therapy and the use of combined hormonal contraceptives (CHC). The inflammation in turn, is an important body\'s response to the aggression and involves several biological mechanisms related and highly regulated, such as coagulation, fibrinolysis, activation of the complement system (CS), oxidation and hormonal regulation. Physiologically, the complement and coagulation systems share components. Activation of coagulation factor XII is controlled by the same regulatory protein activation of the complement inhibitor C1. The deficiency of C1 inhibitor leads to a condition known as hereditary angioedema. However, a clinical manifestation similar to angioedema has been reported in women using CHC or receiving hormone replacement therapy with estrogen (E). The influence of E on coagulation and the CS is also evidenced by the regulatory action of E on the expression of factor XII and its plasma levels. Considering the pleiotropic effects of E, and the interactions of CS and hemostasis, the goal of this study was to evaluate the effect of different CHC on: a) hemolytic activity (HA) CS and activation of classical/lectin and alternative pathways, b) the opsonizing activity of the CS in mediating the oxidative burst of neutrophils, and c) the function of receptors for complement (CR) in mediating the oxidative burst (OB) of neutrophils. We studied 5 different CHC and data showed: a) drospirenone + 30g E increase of the OB neutrophils mediated by CR; b) gestodene + 20g E had a reduced opsonizing ability; c) levonorgestrel + 30g E and gestodene + 20g E promoted a reduction of neutrophils positive for the expression of CR1, d) drospirenone + 30g E and drospirenone + 20g E promoted an increase in HA for classical pathway (CP); e) levonorgestrel + 30g E reduced the HA for CP; f) drospirenone + 30g E and gestodene + 20g E and levonorgestrel + 30g E reduced the serum level of C4d; g) levonorgestrel + 30g E showed an increase of the serum level of C1 inhibitor; h) none of CHC showed differences in activation of the alternative pathway in CS. The results show the importance of considering the different groups of CHC in comparison with the control group, since some differences were significant only for CHC in particular. These observations may contribute to the understanding of the mechanisms involved in the pathophysiology of inflammatory processes associated with estrogen use.
123

Interação da proteína de superfície LcpA de Leptospira com Fator H, principal regulador solúvel da via alternativa do sistema complemento humano / Interaction of the surface protein LcpA from Leptospira with Factor H, the main soluble regulator of the alternative pathway of human complement system

Ludmila Bezerra da Silva 03 July 2013 (has links)
A leptospirose é uma zoonose de distribuição mundial, com maior incidência nas regiões tropicais. As bactérias que causam a doença pertencem ao gênero Leptospira, família Leptospiracea e ordem Spirochaetales. A leptospirose é mantida na natureza pela colonização persistente dos túbulos renais proximais dos animais portadores. Uma estratégia adotada por estas espiroquetas para sobreviver à ação do sistema imune inato do hospedeiro é a capacidade que possuem de interagir com os reguladores do sistema complemento Fator H (FH) e proteína de ligação a C4b (C4BP). O sistema complemento é um componente vital da imunidade inata, uma vez que desempenha um papel crucial na defesa do hospedeiro, particularmente contra bactérias Gram-negativas. Dados recentes gerados por nosso grupo mostraram que C4BP interage com a proteína de superfície LcpA de Leptospira. Com cerca de 20 kDa, essa proteína é capaz de se ligar a C4BP purificado ou solúvel no soro de maneira dose-dependente. Uma vez ligado à proteína, C4BP permanece funcional agindo como cofator de Fator I na clivagem de C4b. O presente estudo teve como principal objetivo avaliar a interação da proteína LcpA com FH humano, principal regulador solúvel da via alternativa do sistema complemento. A proteína LcpA e suas porções N-Terminal, Intermediária e CTerminal recombinantes foram purificadas por cromatografia de afinidade a metal a partir da fração insolúvel. A interação dessas proteínas com FH foi avaliada por dois métodos distintos: ELISA e Western blot com overlay. Os resultados indicaram que a porção C-Terminal da proteína LcpA é responsável pela interação com FH. Curiosamente, C4BP também se liga a esse domínio da proteína. Uma vez que esses dois reguladores solúveis do sistema complemento interagem com o mesmo segmento da LcpA, realizaram-se, a seguir, ensaios de competição com o objetivo de avaliar se ambos compartilhariam os mesmos sítios de interação. Os dados mostraram que FH e C4BP devem se ligar a sequências distintas desta proteína. Com o objetivo de se avaliar a funcionalidade de FH ligado à LcpA, realizou-se um ensaio para investigar sua atividade de co-fator de Fator I na clivagem de C3b. Produtos de degradação de 46 kDa e 43 kDa da cadeia α' de C3b foram detectados, indicando que FH permanece funcional. Em se tratando de uma proteína com funções relacionadas ao processo de evasão ao sistema imune inato, decidiu-se realizar ensaios de desafio em modelo de hamster com a finalidade de se avaliar seu potencial imunoprotetor. Os três ensaios realizados indicaram que a proteína não é capaz de conferir proteção. Os ensaios de ELISA visando à avaliação dos títulos de anticorpos mostraram que LcpA não é imunogênica, fato que explica os resultados dos ensaios de desafio observados. Portanto, embora interaja com moléculas do hospedeiro e pareça contribuir para o processo de evasão ao sistema imune inato, essa proteína de membrana não se mostrou promissora como candidato vacinal contra leptospirose. / Leptospirosis is a zoonosis of global distribution, with higher incidence in tropical areas. The bacteria that cause the disease belong to the genus Leptospira, family Leptospiracea and order Spirochaetales. Leptospirosis is maintained in nature by persistent colonization of proximal renal tubules of carrier animals. One strategy adopted by these spirochetes to escape from host´s innate immune system is the ability to interact with the complement regulators Factor H (FH) and C4b Binding Protein (C4BP). The complement system is a vital component of the innate immune system, being crucial for host´s defense, particularly against Gram-negative bacteria. According to our recent published data, C4BP interacts with the leptospiral surface protein LcpA. This 20 kDa outer membrane protein binds both purified and serum C4BP in a dose-dependent manner. Once bound, C4BP remains functional acting as a cofactor for Factor I in the cleavage of C4b. In the present study we evaluated the interaction of LcpA with human FH, the main soluble regulator of the alternative pathway of complement. The intact protein as well as its N-terminal, intermediate and C-terminal portions were purified by metal-affinity chromatography from the insoluble pellet. The interaction of these proteins with FH was evaluated by two distinct methods: ELISA and Western blot overlay. Our results indicate that the C-terminal domain of LcpA mediates interaction with FH, and also with C4BP. Since both complement regulators interact with the same fragment of LcpA, we next performed competition assays to assess if they would share binding sites. According to our data, FH and C4BP have distinct binding sites on LcpA. Cofactor activity of FH bound to immobilized LcpA was confirmed by detecting the C3b α' chain cleavage fragments of 46 and 43 kDa upon incubation with Factor I, thus indicating that it remains functionally active. Given the LcpA´s role in host´s innate immune evasion, we also evaluated its vaccine potential in a hamster model. Data from three challenge assays indicated that the protein can not afford protection. Low ELISA antibody titers of hamsters immunized with LcpA were observed, which strongly suggests that this protein is not immunogenic. In conclusion, LcpA interacts with host´s molecules and seems to contribute to the bacterial immune evasion. Nevertheless, this outer membrane protein is not a promising vaccine candidate against leptospirosis.
124

On the preconditioning in the domain decomposition technique for the p-version finite element method. Part II

Ivanov, S. A., Korneev, V. G. 30 October 1998 (has links) (PDF)
P-version finite element method for the second order elliptic equation in an arbitrary sufficiently smooth domain is studied in the frame of DD method. Two types square reference elements are used with the products of the integrated Legendre's polynomials for the coordinate functions. There are considered the estimates for the condition numbers, preconditioning of the problems arising on subdomains and the Schur complement, the derivation of the DD preconditioner. For the result we obtain the DD preconditioner to which corresponds the generalized condition number of order (logp )2 . The paper consists of two parts. In part I there are given some preliminary results for 1D case, condition number estimates and some inequalities for 2D reference element. Part II is devoted to the derivation of the Schur complement preconditioner and conditionality number estimates for the p-version finite element matrixes. Also DD preconditioning is considered.
125

Structure/Function analysis of the Staphylococcus aureus extracellular adherence protein and the human innate immune system

Woehl, Jordan Lee January 1900 (has links)
Doctor of Philosophy / Biochemistry and Molecular Biophysics Interdepartmental Program / Brian V. Geisbrecht / The pathogenic bacterium Staphylococcus aureus actively evades many aspects of human innate immunity by expressing a series of secreted inhibitory proteins. A number of these proteins have been shown to specifically bind to and inhibit components of the complement system. Since complement is known to play a significant role in the pathophysiology of human inflammatory diseases, our long-term goal is to understand the structure, function, and mechanism of Staphylococcal immune evasion proteins to develop complement-targeted therapeutics. Since its discovery, the extracellular adherence protein (Eap) has been shown to be a crucial component in the pathogenesis and survival of S. aureus through its ability to interact and inhibit multiple aspects of the innate immune system. We have shown that Eap inhibits the classical and lectin pathways of complement by a previously undescribed mechanism. Specifically, Eap binds with nanomolar affinity to complement protein C4b, and thereby blocks binding of the classical and lectin pathway pro-protease C2 to C4b. This effectively eliminates formation of the CP/LP C3 proconvertase, which is required for amplification of downstream complement activity and subsequent inflammatory events. The full-length, mature Eap protein from S. aureus strain Mu50 consists of four ~97 residue domains, each of which adopt a similar beta-grasp fold, and are connected to one another through short linker regions that give rise to an elongated, but structured protein. Through multiple structural and functional assays, we have identified the 3rd and 4th domains of Eap as being critical for interacting with C4b and subsequent inhibition of the complement cascade. Alternative approaches to a standard co-crystal structure of Eap34 bound to C4b provided evidence that Eap domains 3 and 4 both contain a low affinity, but saturable binding site for C4b; we were able to map these sites to the α-chain and γ-chain, specifically the metal-ion-dependent adhesion site of the C345c domain, of C4b, both of which have been previously shown to be required for pro-protease binding. To provide higher resolution information, we took advantage of the abundance of surface exposed lysines in Eap34, and employed a lysine-acetylation foot printing mass spectrometry technique. This identified seven lysines in Eap34 that undergo changes in solvent exposure upon C4b binding and confirmation of these residues was done through site-directed mutagenesis, followed by direct binding and functional assays. Together, these results provide structural and functional insight into one of the many ways that Staphylococcus aureus can evade the killing powers of the innate immune system. Future plans are directed at conducting site-specific screens to identify small molecule/peptide compounds that target the Eap34 binding site on C4b. Such molecules would constitute attractive lead compounds in the search for specific inhibitors of the classical and lectin complement pathways.
126

Evidence for the alternative pathway of complement activation in the nurse shark

Culbreath, Lieneke Cecile 25 November 1992 (has links)
Complement is activated via two pathways: classical (CCP) and alternative (ACP). The CCP has been demonstrated in the nurse shark. The ACP has not been demonstrated in any cartilagenous fish. Nurse shark serum was evaluated for complement activity by its ability to lyse heterologous erythrocytes. As CCP activity requires calcium and magnesium, activity of shark serum chelated with EGTA (a selective calcium chelator) or EDTA (a chelator of calcium and magnesium) was assessed. Activity remained in serum chelated with EGTA but not EDTA. Furthermore, activity of chelated serum was enhanced by added magnesium. Activation of shark complement by activators of mammalian ACP (zymosan, LPS, inulin, CVF) was assessed. Complement was activated by zymosan and LPS. Immunoblots were employed, with limited success, to demonstrate complement proteins in nurse shark serum. This study unequivocally demonstrates that the ACP is present in the primitive nurse shark.
127

Proteoglycans of the human macula : normal distribution and age-related changes

Keenan, Tiarnan Daniel January 2013 (has links)
Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries. The Y402H polymorphism in complement factor H (CFH) is a common and important risk factor, where CFH is an inhibitor of the alternative complement pathway. The disease-associated protein variant (CFH402H) binds poorly to aged human macular Bruch’s membrane (BM), a site of AMD formation. Heparan sulphate (HS) is the major binding site for CFH in this extracellular matrix. Unlike CFH402Y, CFH402H binds poorly to lowly sulphated HS. The aim of this research was to investigate the presence and distribution of proteoglycan (PG) core proteins and glycosaminoglycans (GAGs) in the normal adult human macula, and to analyse potential changes with age in the quantity and composition of HS and other potential molecular determinants of disease in BM. Post mortem human eye tissue was obtained from consenting donors (age range 18-93 years), and either dissected into tissue layers or used to produce frozen macular tissue sections. Proteomic analysis of different retinal tissue layers was performed by tandem mass spectrometry. Immunofluorescence microscopy was undertaken on the macular tissue sections. Compositional analysis of HS in BM was performed by 2-aminoacridone labelling of HS disaccharides and reverse phase high performance liquid chromatography against reference HS disaccharide standards. PG core proteins were identified in BM and other macular tissue layers, including members of the basement membrane, hyalectan and short leucine-rich repeat PG families. HS, chondroitin sulphate, dermatan sulphate and hyaluronan were present throughout the retina and choroid, but keratan sulphate only in the sclera. The mean quantity of HS in BM was 47% lower (p=0.006) in old donors (n=13, 64-92 years), compared to young donors (n=6; 26-39 years). The mean level of HS sulphation was also lower in old donors, e.g. 34% vs. 39% (p=0.02) N-sulphated HS. The mean level of HS in macular BM by immunohistochemistry was approximately 50% lower (p=0.02) in old donors (n=10, 18-93 years), and the mean level of the HS PG core protein perlecan was reduced by 85% (p=0.01; n=18, 27-90 years). High levels of complement activation (C3b and membrane attack complex) were observed in some young donors. Reduced HS was associated with increased complement activation in some donors (r2 0.30). A combination of proteomics and immunohistochemistry approaches has provided the first comprehensive analysis of the presence and distribution of PG core proteins and their associated GAG chains throughout the macular layers of the normal adult human retina. These demonstrate a differential distribution according to PG core protein, GAG class and GAG sulphation state. The quantity of HS decreases substantially with age in human BM, and its sulphation level also decreases. The presence of less HS in old BM would make fewer binding sites available for CFH, and could contribute to AMD pathogenesis through increased complement activation. This idea is supported by the observation that reduced HS is associated in some individuals with increased C3b in BM. These findings have important implications for unravelling mechanisms of ocular disease and planning novel therapeutic strategies, particularly in the case of AMD.
128

The complement fixation test in the diagnosis of the rickettsial diseases of man tick borne relapsing fever, African human trypanosomiasis, and Rift valley fever

Wolstenholme, Brian 03 May 2017 (has links)
No description available.
129

CRP After 2004

Agrawal, Alok 01 January 2005 (has links)
C-reactive protein (CRP) that has been conserved throughout evolution is a host-defense molecule. Its attraction towards phosphocholine-ligands, such as modified low-density lipoprotein, and apoptotic cells leads to the "masking" of these substances that have the capabilities to otherwise engage in deleterious activities. Complement activation by CRP complexes and the modulation by CRP of complement activation by its ligands add up to its beneficial effects. In the presence of CRP, production of membrane-damaging last product of the complement pathway is arrested. CRP is currently serving as an indicator of cardiovascular diseases, but to pinpoint the role of CRP in atherosclerosis, a drug that can lower cholesterol levels, but not the CRP levels, is needed for experimentation.
130

Restrained Domination in Self-Complementary Graphs

Desormeaux, Wyatt J., Haynes, Teresa W., Henning, Michael A. 01 May 2021 (has links)
A self-complementary graph is a graph isomorphic to its complement. A set S of vertices in a graph G is a restrained dominating set if every vertex in V(G) \ S is adjacent to a vertex in S and to a vertex in V(G) \ S. The restrained domination number of a graph G is the minimum cardinality of a restrained dominating set of G. In this paper, we study restrained domination in self-complementary graphs. In particular, we characterize the self-complementary graphs having equal domination and restrained domination numbers.

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