O Trypanosoma brucei é o agente etiológico da Tripanossomíase Africana Humana. Este protozoário é um parasita extracelular que possui um único flagelo e um citoesqueleto de alta estabilidade, responsável por vários processos celulares como motilidade, morfologia, infectividade e divisão celular. Em todos os gêneros da família Trypanosomatidae foram descritas proteínas de alto peso molecular (500-3500 kDa) as quais, além do papel estrutural, podem estar envolvidas na organização e regulação do citoesqueleto e seus constituintes. Este projeto teve como objetivo caracterizar no âmbito celular, bioquímico e molecular as proteínas gigantes de T. brucei e determinar os seus papéis funcionais na biologia do parasito. A partir do isolamento do citoesqueleto de T. brucei e análise por SDS-PAGE, produzimos anticorpos contra as proteínas gigantes que serviu como ferramenta para realização de Western Blotting (WB) e imunofluorescência no estudo das propriedades moleculares destas proteínas. O sequenciamento por espectrometria de massas foi utilizado para determinação da sequência primária parcial destas proteínas e identificação dos genes em no banco de dados TriTrypDB. Aqui, mostramos que as proteínas de alta massa molecular se localizam em estruturas essenciais para a regulação do citoesqueleto como na zona de adesão flagelar (FAZ), bem como no complexo tripartido responsável pela adesão do flagelo ao cinetoplasto. A espectrometria de massas revelou 19 novas proteínas de alta massa molecular ainda não estudadas em T. brucei dentre as quais 2 foram caracterizadas funcionalmente: FAZ10 e Tb927.8.3540. Para investigar os seus papeis biológicos utilizamos o modelo de silenciamento gênico por RNA de interferência. O silenciamento da proteína FAZ10 levou ao destacamento do flagelo, ao reposicionamento incorreto dos núcleos e cinetoplastos, e mais importante ao erro na definição do local de ingressão do sulco de clivagem durante a citocinese, em formas procíclicas e sanguícolas de T. brucei. Por sua vez, a proteína Tb927.8.3540 é responsável pela estabilização do citoesqueleto de microtúbulos e formação do FAZ e flagelo. Quando ausente nas células, estas adquirem um formato esférico com a presença de um flagelo internalizado. Em ambos os casos, as células induzidas apresentam inibição da proliferação celular e o acúmulo de células multinucleadas na cultura. O estudo funcional das proteínas gigantes revelou que elas possuem um papel central na morfogênese do T. brucei, agindo diretamente na organização e formação de estruturas do citoesqueleto, na manutenção da adesão flagelar, e no direcionamento da citocinese. / Trypanosoma brucei, the causative agent of sleeping sickness or Human African Trypanosomiasis (HAT), has been used as experimental model for cellular, biochemical and molecular studies. This is an extracellular protozoan parasite that has a single flagellum and a highly stable cytoskeleton, responsible for many cellular processes such as motility, morphology, infectivity and cell division. In Trypanosomatidae family, a novel class of High Molecular Weight Proteins (HMWPs; 500-3500 kDa) has been described, which besides their structural role, may play a role in cytoskeleton organization and regulation. Trypanosomatids cytoskeletons contain abundant HMWPs, but many of their biological functions are still unclear. Here, we aimed to describe the cellular and molecular properties of these proteins, and to determine their functional roles in the parasite biology. SDS-PAGE was used to analyze T. brucei cytoskeletons. Also, the HMWP bands were injected in mouse in order to produce polyclonal antibodies, which were used as a molecular tool in Western Blotting (WB) and immunofluorescence analysis. Here we show that the high molecular weight proteins are located on essential structures for the regulation of the cytoskeleton such as the flagellar adhesion zone (FAZ) and the tripartite complex, which connects the flagellum to the kinetoplast. Detergent-extracted cytoskeletons were also analyzed by gradient SDS-PAGE and the HMWP bands were sent to mass spectrometry analysis. We able to identify 19 new high molecular weight proteins most of which are uncharacterized so far in T. brucei. Here, we report the characterization of two giant proteins: FAZ10 and Tb927.8.3540. To investigate their biological roles we used a model of gene silencing by RNA interference (RNAi). Our data showed that FAZ10 is an essential giant cytoskeletal protein in both procyclic and bloodstream parasite life cycle stages, since its depletion led to defects in cell morphogenesis, flagellum attachment and kinetoplast and nucleus positioning. More importantly, ablation of FAZ10 impaired the timing and placement of the cleavage furrow during cytokinesis, resulting in premature or asymmetrical cell division. In turn, the Tb927.8.3540 protein is responsible for the stabilization and regulation of the microtubule cytoskeleton as well as the flagellum and FAZ. In its absence, cells acquire a spherical shape together with an internalized flagellum. In both cases, the resulting phenotype results in inhibition of cell proliferation and accumulation of multinucleated cells in culture. The functional study of the giant proteins revealed that they have a central role in morphogenesis of T. brucei, acting directly on the organization and regulation of cytoskeletal structures, such as the flagellum and the FAZ.

As energias e larguras de escape das Ressonâncias Gigantes, são calculadas utilizando-se técnicas de projeção visando incluir as ressonâncias de partícula-única nos cálculos de RPA (\"Random Phase Approximation\"). As equações de RPA obtidas são complexas, e as larguras de escape são interpretadas como sendo a parte imaginaria das soluções em energia. Os cálculos são feitos para a RGE1( O16 ) e RGE0 ( Zr90 ). Para o Zr90, os espectros das partículas emitidas pela RGE0, prótons e nêutrons, são calculados através do modelo híbrido. Devido à existência de mais do que um tipo de partícula sendo emitida, as analises são feitas dentro da aproximação de independência entre os canais de partículas no formalismo do modelo híbrido. / The energy and the escape of the Giant Resonances are calculated utilizing the projection to include the single-particle resonances in complex RPA (Random Phase Approximation) calculations. The escape widths are interpreted as the imaginary parts of the energy solution of the RPA equations. The Calculations are performed for the RGE1 ( O16 ) and RGE0 ( Zr90 ). For the Zr90 the spectra of the particles ejected by the RGE0, protons and neutrons, are calculated within the hybrid model. The analysis are made through the channels independence in the hybrid model formalism.

by Chiu Shui-fan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1989. / Bibliography: leaves 186-203.

Giant Cell arteritis (GCA) is a systemic inflammatory disease that affects arteries of medium- and large size. Symptoms of GCA such as headache and fever usually promptly improve with treatment of glucocorticoids. Apart from advanced age, female sex and Northern-European descent, risk factors for GCA are unknown. Most studies have found that life expectancy for patients with GCA is not reduced compared with the general population and studies on cardiovascular disease in GCA have provided conflicting results. Data for the studies of this thesis are drawn from the Reykjavik Study (RS) that is a general population-based cohort study with continuous surveillance for coronary heart disease and vital status. Subjects born in 1907–1934 and living in Reykjavik, Iceland or adjacent communities in 1966 were invited for study visit from 1967-1994. Information on cardiovascular risk factors were collected at study visit. Diagnosis of GCA for this study was based on re-examination of all temporal arteries biopsies (TAB) from members of the RS cohort; however, information was also obtained from the original pathology report. Of 19,360 subjects included in the RS, 194 developed GCA during the follow-up period. Body mass index was inversely associated with the occurrence of GCA. Among men, but not women, hypertension was associated and smoking inversely associated with the occurrence of GCA. Among women, but not men, GCA was associated with coronary heart disease. Subjects with GCA had approximately 50% increase in mortality risk compared with the general population. Increase mortality was mainly observed among GCA patients based on the diagnosis of re-examination of TAB; however, no such an association was found if diagnosis of GCA was made based on the original pathology report. Those subjects were likely not clinically diagnosed with GCA, signaling that treatment for GCA might be beneficial with respect to mortality risk.

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2015-07-29T22:02:33Z No. of bitstreams: 1 Disserta??o Final_Patr?cia Herc?lia de Almeida.pdf: 2058812 bytes, checksum: f101704775fb70cb9a74a8e794349727 (MD5) / Made available in DSpace on 2015-07-29T22:02:33Z (GMT). No. of bitstreams: 1 Disserta??o Final_Patr?cia Herc?lia de Almeida.pdf: 2058812 bytes, checksum: f101704775fb70cb9a74a8e794349727 (MD5) Previous issue date: 2014-03-27 / Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB / The African snail Achatina fulica Bowdich, 1822, is an invasive species that cause environmental and economic damage, as to human and animal health. The aim of this study was to evaluate the occurrence and parasitological aspects of A. fulica in Feira de Santana (BA). To assess the occurrence of A. fulica, sampling was made from January to June 2013 at four points in the urban perimeter of the city. In the laboratory animals were measured as the total length of the shell and the total mass. From these data the degree of development of the population was estimated, and the relationships between morphometric and climatic variables and the condition factor were calculated. During this period were collected 600 snails showing predominant length in the range of 57.0 to 47.6 mm. Results allowed to infer that the population of A. fulica in these sampling points is in decline, since in these areas were found juvenile and young animals. There was no association between climatic and morphometric variables. The relationship between total length and weight showed that A. fulica presented a negative allometric growth. The condition factor presented variations on time over the six months of collection. In order to evaluate parasitological aspects in A. fulica, animals were collected from may 2012-to june 2013 in eight areas in the urban perimeter of the city.The animals were collected early in the morning and transported to the laboratory of the Zoonoses and Public Health Research Group -UEFS. Each clam was analyzed individually using the artificial digestion technique in hydrochloric acid solution with identification of larvae found. The larvae have been identified as Metastrongylidae were submitted to the polymerase chain reaction for the identification of the genus Angyostrongylus. 220 animals were tested and in 28 (12.7; 95: 8.6 -17.9) were found at least one of four morphotypes of nematodes. Angyostrongylus has not been registered in snails examined. There was no association between climatic variables and the presence of larvae. The location of collection and the size of the snail influenced in the larvae of nematodes. Both parasited and not parasitised animals have negative allometric growth. The relative condition factor did not differ significantly between the groups. Nested-PCR has been used to search Cryptosporidium ssp and Sarcocystidae DNA in fecal samples of Achatina fulica. Amplicons compatibles with Cryptosporidium ssp were found in 2 of 223 stool samples analyzed. Of the 223 stool samples analysed, in 58 samples we found the 290 base pair fragment expected for Sarcocystidae, and then subjected to RFLP. Of these, 41 samples were cleaved by enzymes used in this study, producing a profile compatible with T. gondii. The other 17 samples were not compatible with Sarcocystidae. This is the first record of the occurrence of A. fulica in Feira de Santana (BA), with research of association of climatic variables to the biometric parameters of the animals. These results indicate the presence of animal and humana parasites in Achatina fulica in the municipality of Feira de Santana, demonstrating the potential of these animals in the maintenance and spread of these agents in the environment. / O caramujo africano Achatina fulica Bowdich, 1822, ? uma esp?cie invasora que causa preju?zos ambientais, econ?micos e a sa?de humana e animal. O objetivo desse estudo foi avaliar a ocorr?ncia e os aspectos parasit?rios de Achatina fulica no munic?pio de Feira de Santana (BA). Para avalia??o da ocorr?ncia de A. fulica foram feitas coletas de janeiro a junho de 2013 em quatro pontos no per?metro urbano do munic?pio. No laborat?rio os animais foram mensurados quanto ao comprimento total da concha e a massa total. A partir desses dados o grau de desenvolvimento da popula??o foi estimado, as rela??es entre as vari?veis morfom?tricas e clim?ticas e o fator de condi??o foram calculados. Durante esse per?odo foram coletados 600 caramujos apresentando comprimento predominante no intervalo de 47,6-57,0mm. Os resultados permitiram inferir que a popula??o de A. fulica nos pontos de coleta estudados est? em decl?nio, j? que nessas ?reas foram encontrados animais juvenis e jovens. N?o houve associa??o entre as vari?veis clim?ticas e morfom?tricas. A rela??o entre o comprimento total e a massa corporal mostrou que A. fulica apresentou um crescimento alom?trico negativo. O fator de condi??o apresentou varia??es pontuais ao longo dos seis meses de coleta. A fim de avaliar os aspectos parasit?rios em A. fulica foram realizadas coletas de maio de 2012 a junho de 2013 em oito ?reas no per?metro urbano do munic?pio, com registro de observa??es sobre os locais de coleta. Cada molusco foi analisado individualmente utilizando a t?cnica de digest?o artificial em solu??o de ?cido clor?drico, com identifica??o das larvas encontradas. As larvas identificadas como Metastrongylidae foram submetidas ? rea??o em cadeia pela polimerase para a identifica??o do g?nero Angyostrongylus. Foram analisados 220 animais e em 28 (12,7%; IC95%: 8,6-17,9) foram encontrados pelo menos um de quatro morfotipos de nemat?deos. Angyostrongylus n?o foi registrado nos caramujos examinados. N?o houve associa??o entre vari?veis clim?ticas e a presen?a de larvas. O local de coleta e o tamanho do caramujo influenciaram no encontro de larvas de nemat?deos. Tanto animais parasitados quanto n?o parasitados apresentaram um crescimento alom?trico negativo. O fator de condi??o relativo n?o diferiu significamente entre os grupos. A fim de pesquisar a presen?a de DNA Cryptosporidium ssp. e Sarcocystidae nas amostras fecais de Achatina fulica foi utilizada a t?cnica de nested-PCR (nPCR). Para Cryptosporidium ssp., amplicons compat?veis com este parasito foram encontrados em 2 de 223 amostras de fezes analisadas. Das 223 amostras de fezes de Achatina fulica submetidas ? nPCR para detec??o de Sarcocystidae, 58 amostras amplificaram o fragmento esperado de 290 pares de base, sendo ent?o submetidas ? RFLP. Destas, 41 amostras foram clivadas pelas enzimas utilizadas nesse estudo, produzindo um perfil compat?vel com T. gondii. As outras 17 amostras n?o foram compat?veis com o Sarcocystidae. Este ? o primeiro registro da ocorr?ncia de A. fulica no munic?pio de Feira de Santana (BA), com pesquisa da associa??o das vari?veis clim?ticas aos par?metros biom?tricos dos animais estudados. Estes resultados indicam que h? presen?a de parasitos de interesse em sa?de animal e humana em Achatina fulica no munic?pio de Feira de Santana, Bahia, demonstrando o potencial destes animais na manuten??o e dispers?o destes agentes no ambiente.

The steady growth of the export of Peruvian Giant Squid (commonly known as Pota) in absolute as well as relative values - as percentage of the also increasing Peruvian Exports- represents an opportunity to develop the still incipient Peruvian Pota Industry, a more inclusive one in comparison other consolidated export industries in Peru. The first two chapters of this document describe the dynamics of the Peruvian Pota Industry and Giant Squid Great China market. In the third chapter it is carried out a managerial analysis of this industry using SWOT analysis and Porter’s Diamond Model. The Great China Market itself is also analyzed using SWOT analysis regarding its potential as destination of the Peruvian Pota. Finally in the fourth chapter it is exposed some strategies for the Peruvian Pota companies in order to better satisfy the growing demand but at the same time better confront the challenging international competition to succeed in the Great China Market.

This study investigated the role of an invasive tall cane, Arundo donax L. (Arundo), in the riparian water cycle. Four 100 meter transects were arrayed perpendicular to the lower Rio Grande in southwest Texas. The first objective was to determine the primary water source for Arundo by using naturally occurring stable isotopes. Surface soil, river water, groundwater, precipitation and rhizome samples were collected every month during 2010 and 2011 growing seasons, which coincided with a major flood that saturated soils in the first year followed by extreme drought in the second year. The second objective was to characterize how Arundo water use varied with water availability gradients in the riparian zone. Leaf gas exchange and leaf delta13C were measured along potential moisture gradients. The third objective was to understand the interaction between groundwater and surface water, and whether Arundo water use affected daily groundwater fluctuations. The isotope ratio of rhizome water was consistent with shallow soil moisture uptake and with previous observations of a relatively shallow, fibrous root system. Floodwater from July 2010 persisted in the soil for at least a year despite a severe drought, and became the dominant water source for Arundo during much of the study period. Although the alluvial water table in this floodplain was shallow (< 6 m) and subject to changes in river level, groundwater seemed not to be an important source for Arundo, so long as the soil moisture was sufficient. In this study, Arundo was not found to experience soil moisture limitation, and the spatial variability of Arundo transpiration was not associated with any soil moisture availability gradients. Arundo was found to close its stomata in response to increasing vapor pressure deficit (VPD), causing declining transpiration rate and increasing leaf delta13C composition. Significant exchange between the river and the alluvial groundwater was reflected in the similarity of isotopic compositions and the high correlation between river and groundwater elevations. Cross correlation analysis showed that over 50% of the diurnal groundwater fluctuations were caused by river stage changes. Consistent with the above ecophysiological and stable isotope results, Arundo water use was not found to influence daily groundwater fluctuations.

The recent discovery that a spin-polarized current can exert a large torque on a ferromagnet, through direct transfer of spin angular momentum, offers the possibility of electrical current controlled manipulation of magnetic moment in nanoscale magnetic device structures. This so-called spin torque effect holds great promise for two applications, namely, spin torque oscillators (STOs) for wireless communication and radar communication, and spin transfer torque RAM (STT-RAM) for data/information storage.   The STO is a nanosized spintronic device capable of microwave generation at frequencies in the 1-65 GHz range with high quality factors. Although the STO is very promising for future telecommunication, two major shortcomings have to be addressed before it can truly find practical use as a radio-frequency device. Firstly, its very limited output power has to be significantly improved. One possibility is the synchronization of two or more STOs to both increase the microwave power and further increase the signal quality. Synchronization of serially connected STOs has been suggested in this thesis. In this configuration, synchronization relies on phase locking between the STOs and their self-generated alternating current. While this locking mechanism is intrinsically quite weak, we find that the locking range of two serially connected spin-valve STOs can be enhanced by over two orders of magnitude by adjusting the circuit I-V phase to that of an intrinsic preferred phase shift between the STO and an alternating current. More recently, we have also studied the phase-locking of STOs based on magnetic tunnel junctions (MTJ-STO) to meet the power specifications of actual application where the rf output levels should be above 0 dBm (1 mW). In addition to the spin torque terms present in GMR spin valves, MTJs also exhibit a significant perpendicular spin torque component with a quite complex dependence on both material choices and applied junction bias. We find that the perpendicular torque component modifies the intrinsic preferred I-V phase shift in single MTJ-STOs in such a way that serially connected STOs synchronize much more readily without the need for additional circuitry to change the I-V phase.   Secondly, equal attention has been focused on removing the applied magnetic field for STO operation, which requires bulky components and will limit the miniaturization of STO-based devices. Various attempts have been made to realize STOs operating in zero magnetic field. By using a tilted (oblique angle) polarizer (fixed layer) instead of an in-plane polarizer (standard STO), we show zero field operation over a very wide polarizer angle range without sacrificing output signal. In addition, the polarizer angle introduces an entirely new degree of freedom to any spin torque device and opens up for a wide range of additional phenomena.   The STT-RAM has advantages over other types of memories including conventional MRAM in terms of power consumption, speed, and scalability. We use a set of simulation tools to carry out a systematic study on the subject of micromagnetic switching processes of a device for STT-RAM application. We find that the non-zero k spin wave modes play an important role in the experimentally measured switching phase boundary. These may result in telegraph transitions among different spin-wave states, and be related to the back-hopping phenomena where the switching probability will decrease with increasing bias in tunnel junctions. / QC 20100819

<p>We have performed a measurement of the photodisintegration of the lithium isotopes, 6Li and 7Li, using a monochromatic, polarised photon beam and a segmented neutron detector array which covers approximately 1/4 of 4Î srad. Using time-of-flight and scintillator light-output spectra we separate the data into individual reaction channels. This work is motivated by the need to compare with recent theoretical predictions and to provide data for future theoretical work. <p>For the photodisintegration of 6Li we took data at 12 photon energies between 8 and 35 MeV. We describe the data using a model consisting of two-body reaction channels and obtain angular distributions and absolute cross sections for many of these reaction channels. We compare our results with a recent Lorentz integral transform calculation (Bacca et al. Phys. Rev. C 69, 057001 (2004)). Our results are in reasonable agreement with the calculation, in contradiction with previous experimental results. <p>For the photodisintegration of 7Li, we took data at 9 photon energies between 10 and 35 MeV. We obtain cross sections for the reaction channel 7Li + Á ¨ n + 6Li(g.s.) at all photon energies with angular distributions at all but the highest energy. We obtain angular distributions and total cross sections for reaction channels involving excited states of the daughter nucleus, 6Li, at select energies. We hope that these measurements will provide incentive for new theoretical calculations. <p>We observe neutrons that can only be described by the reaction channel 7Li+Á ¨ n+6Li(10.0) which necessitates an excited state of 6Li with excitation energy Ex = 10.0 } 0.5 MeV that is not in the standard tables of excited states.

<p>We have performed a measurement of the photodisintegration of the lithium isotopes, 6Li and 7Li, using a monochromatic, polarised photon beam and a segmented neutron detector array which covers approximately 1/4 of 4Î srad. Using time-of-flight and scintillator light-output spectra we separate the data into individual reaction channels. This work is motivated by the need to compare with recent theoretical predictions and to provide data for future theoretical work. <p>For the photodisintegration of 6Li we took data at 12 photon energies between 8 and 35 MeV. We describe the data using a model consisting of two-body reaction channels and obtain angular distributions and absolute cross sections for many of these reaction channels. We compare our results with a recent Lorentz integral transform calculation (Bacca et al. Phys. Rev. C 69, 057001 (2004)). Our results are in reasonable agreement with the calculation, in contradiction with previous experimental results. <p>For the photodisintegration of 7Li, we took data at 9 photon energies between 10 and 35 MeV. We obtain cross sections for the reaction channel 7Li + Á ¨ n + 6Li(g.s.) at all photon energies with angular distributions at all but the highest energy. We obtain angular distributions and total cross sections for reaction channels involving excited states of the daughter nucleus, 6Li, at select energies. We hope that these measurements will provide incentive for new theoretical calculations. <p>We observe neutrons that can only be described by the reaction channel 7Li+Á ¨ n+6Li(10.0) which necessitates an excited state of 6Li with excitation energy Ex = 10.0 } 0.5 MeV that is not in the standard tables of excited states.