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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.
281

Best Effort MPI/RT as an Alternative to MPI: Design and Performance Comparison

Angadi, Raghavendra 13 December 2002 (has links)
The Real-Time Message Passing Interface (MPI/RT) is an emerging real-time communications middleware standard for distributed real-time applications. The Message Passing Interface (MPI) is the de facto standard for high performance parallel application development. In this thesis, we describe how MPI/RT with best effort quality of service can be used as an alternative for MPI. Mercury Computer Systems' RACE embedded parallel computer is used as the platform for comparison of design and performance of these two standards. The main advantages MPI/RT has over MPI are its explicit support for communication channels and its emphasis on early binding. Design and implementation of best effort MPI/RT on Mercury is described and its performance is compared with MPI in order to illustrate how MPI/RT features allow implementations to exploit the underlying platform more optimally. The results for the benchmarks show that MPI/RT outperforms MPI in almost all cases examined.
282

Differential gene expression and immune regulatory mechanisms in parasite-resistant hair and susceptible wool sheep infected with the parasitic nematode, Haemonchus contortus

MacKinnon, Kathryn Michelle 10 August 2007 (has links)
Among sheep producers, the parasitic nematode Haemonchus contortus is a major animal health concern. Caribbean hair sheep are more resistant than conventional wool breeds to this blood-feeding, abomasal parasite. Our objective was to determine differences in the immune response associated with parasite-resistant hair and susceptible wool lambs infected with 10,000 H. contortus and in uninfected controls. Animals were sacrificed and abomasum and lymph node tissues were collected at 3 or 27 days post-infection (PI), and for controls on day 17, 27, or 38 relative to d 0 of infected animals. Blood and fecal samples were collected throughout the study. Lower fecal egg counts, higher packed cell volumes, and heavier lymph nodes of infected hair compared to wool lambs, suggests hair lambs have increased parasite resistance. Greater tissue infiltration of eosinophils (P < 0.05) was observed in hair compared to wool sheep by 3 days PI, with no breed differences in globule leukocytes. Total serum IgA and IgE were greater in control hair versus wool sheep (P < 0.05). After 3, 5, and 21 of infection, total serum IgA (P< 0.05), total lymph node IgE (P < 0.01), but not total serum IgE were greater in hair sheep compared to wool sheep. Gene expression was measured between hair and wool lambs for abomasal and lymph node tissues using bovine cDNA microarrays and real-time RT-PCR. Microarray analysis revealed cell survival, endosome function, gut motility, and anti-coagulation pathways are important in abomasal and lymph node tissues during H. contortus infection. Immune genes, including IL-4, IL-4 Ra, IL-12 Rb1, and IL-12 Rb2, are also highly represented in abomasal or lymph node tissue of infected animals. Eleven genes were evaluated using real-time RT-PCR and included TH1 and TH2 cytokines, cytokine receptors, and IgE. Parasite infection leads to increased expression of IL-13 and IgE in both tissues and breeds when compared to control animals. Breed comparison of gene expression shows resistant hair sheep produce a stronger modified TH2-type immune response during infection. Differential cell infiltration, antibody production, and regulation of TH2 cytokines between breeds may be partially responsible for differences in parasite resistance. / Ph. D.
283

The Measurement of Quality of Life and its Relationship with Perceived Health Status in Adolescents

Sawatzky, Richard 08 1900 (has links)
Several assumptions of the indirect reflective model of the Multidimensional Students’ Life Satisfaction Scale (MSLSS) were tested to assess its validity as a measure of adolescents’ satisfaction with life generally and with five important life domains (family, friends, living environment, school, and self perception). We also examined whether adolescents’ perceived mental and physical health status significantly explained their global quality of life (QOL) and whether these relationships were mediated by their satisfaction with the five life domains. The data were taken from a cross-sectional health survey of 8,225 adolescents in 49 schools in British Columbia, Canada. Global QOL was measured using Cantril’s ladder and a single-item rating of the adolescents’ satisfaction with their QOL. Confirmatory factor and factor mixture analyses were used to examine the measurement assumptions of the MSLSS, and structural equation modeling was applied to test the hypothesized mediation model. The Pratt index (d) was used to evaluate variable importance. The adolescents did not respond to all MSLSS items in a consistent manner. An abridged 18-item version of the MSLSS was therefore developed by selecting items that were most invariant in the sample. Good model fit was obtained when the abridged MSLSS was used to test the hypothesized mediation model, which explained 76% of the variance in global QOL. Relatively poorer mental health and physical health were significantly associated with lower satisfaction in each of the life domains. Global QOL was predominantly explained by the adolescents’ mental health status (d = 30%) and by their satisfaction with self (d = 42%) and family (d = 20%). Self and family satisfactionwere the predominant mediating variables of the relationships between mental health (45% total mediation) and physical health (68% total mediation) and global QOL.Satisfaction with life domains and perceived physical and mental health can be viewed as conditions that potentially contribute to adolescents’ global QOL. Questions about adolescents’ experiences with important life domains require more attention in population health research so as to target appropriate supportive services for adolescents, particularly those with mental or physical health challenges. / Michael Smith Foundation for Health Research / Canadian Nurses Foundation / Trinity Western University
284

Evidence of Extrahepatic Sites of Replication of the Hepatitis E Virus in a Swine Model

Williams, Trevor Paul Emrys 14 May 2001 (has links)
Hepatitis E virus (HEV) is the major cause of enterically transmitted non-A, non-B hepatitis in many developing countries, and is also endemic in many industrialized countries. Due to the lack of an effective cell culture system and a practical animal model, the mechanisms of HEV pathogenesis and replication are poorly understood. It has been speculated that HEV replicates in sites other than the liver. Since HEV is presumably fecal-orally transmitted it is unclear how the virus reaches the liver and extrahepatic replication could be a possible explanation. The recent identification of swine HEV from pigs affords us an opportunity to systematically study HEV replication in a swine model. We experimentally infected specific-pathogen-free (SPF) pigs with two strains of HEV: swine HEV and the US-2 strain of human HEV. Eighteen pigs (group 1) were each inoculated intravenously with swine HEV, nineteen pigs (group 2) with the US-2 strain of human HEV, and seventeen pigs (group 3) as uninoculated controls. To identify the potential extrahepatic sites of HEV replication using the swine model, two pigs from each group were necropsied at 3, 7, 14, 20, 27, and 55 days post inoculation (DPI). Thirteen different types of tissues and organs were collected from each necropsied animal. Reverse transcriptase PCR (RT-PCR) was used to detect the presence of positive strand HEV RNA in each tissue collected during necropsy at different DPIs. A negative strand-specific RT-PCR was standardized and used to detect the replicative, negative-strand of HEV RNA from tissues that tested positive for the positive strand RNA. As expected, positive strand HEV RNA was detected in almost every type of tissue at some time point during viremic period between 3 and 27 DPI. Positive-strand HEV RNA was still detectable in some tissues in the absence of serum HEV RNA from both swine and human HEV inoculated pigs. However, replicative, negative strand of HEV RNA was detected primarily in the small intestine, lymph nodes, colon, and liver. Our results demonstrate for the first time that HEV replicates in tissues other than the liver and that the gastrointestinal tract is also the target of virus infection. The data from this study may have important implications for HEV pathogenesis, xenotransplantation, and the development of an in vitro cell culture system for HEV. / Master of Science
285

DEVELOPMENT AND APPLICATION OF NOVEL QUANTITATIVE AND QUALITATIVE MOLECULAR TECHNIQUES FOR DETECTION OF INFECTIOUS MYONECROSIS VIRUS (IMNV) IN PACIFIC WHITE SHRIMP LITOPENAEUS VANNAMEI

Andrade, Thales Passos de January 2009 (has links)
Infectious myonecrosis, caused by infectious myonecrosis virus (IMNV), is an important disease of shrimp that has adversely affected the production of cultured Litopenaeus vannamei. The studies reported here were centered on development and/or validation of alternative diagnostic methods for detection of IMNV. Hence, two manuscripts were published in the Journal of Aquaculture and one manuscript was published in the Journal of Fish Diseases. Chapter 2 describes the development of a real-time reverse transcription polymerase chain reaction (real-time RT-PCR) method using TaqMan probe. The results showed that this real-time RT-PCR assay can detect as little as 10 IMNV copies/μl RNA, while the nested RT-PCR can detect 1000 copies/μl RNA. These findings suggest that the TaqMan real-time RT-PCR is “the gold standard” for screening shrimp to protect aquaculture production systems from losses caused by IMNV, because it provides quantification, higher sensitivity and specificity, and because it is less time consuming and less prone to contamination compared to conventional gel-based RT-PCR. In Chapter 3 I evaluated if prolonged storage of infectious myonecrosis virus (IMNV) infected shrimp in Davidson’s AFA fixative can degrade its double-stranded RNA genome resulting in false negative ISH reactions. Shrimp were collected at Day 12 post-injection and fixed in Davidson’s AFA for five different preservation times (1, 2, 4, 7 and 10 days). Hence, in the present report it was found that the length of time (up to 10 days) in Davidson’s AFA did not have a deleterious effect on the ISH reaction for IMNV. The Chapter 4 describes the development of a reverse transcription loop-mediated isothermal amplification and nucleic acid lateral flow (RT-LAMP-NALF) for detection of IMNV. The RT-LAMP-NALF method combines simplified nucleic acid extraction, a reverse-transcription loop-mediated isothermal amplification platform, and one-step visual colorimetric confirmation of the IMNV amplified sequences using a generic NALF qualitative detection test strip. The RT-LAMP-NALF was found to be 100 and 10 times more sensitive than one-step RT-PCR and RT-LAMP (two primer pairs), respectively. These results clearly demonstrate that the RT-LAMP-NALF method is specific, sensitive, can shorten the time for analysis, and has potential application for IMNV diagnosis in resource-poor diagnostic settings.
286

Caracterização molecular de astrovírus em amostras fecais de crianças com gastroenterite em São Paulo, Brasil. / Molecular characterization of astrovirus in stool samples from children with gastroenteritis in São Paulo, Brazil.

Resque, Hugo Reis 14 February 2008 (has links)
O objetivo deste trabalho foi caracterizar astrovírus em amostras fecais coletadas de crianças com e sem diarréia, em São Paulo, Brasil, e divididas em dois grupos, EPM e HU, de acordo com a origem. A detecção foi realizada utilizando-se RT-PCR, com primers específicos. Os resultados para as amostras EPM mostram que 66/234 (28,2%) foram positivas para astrovírus. Para as amostras HU, 18/187 (9,6%) foram positivas. A genotipagem foi realizada com a técnica de nested/RT-PCR. De 66 amostras positivas (EPM), 19 (28,7%) foram caracterizadas como HAstV-1, 4 (6,0%) como HAstV-2, 2 (3,0%) como HAstV-3, 1 (1,5%) como HAstV-5 e 3 (4,5%) como HAstV-8. Das 18 positivas do HU, 1 (5,5%) amostra foi caracterizada como HAstV-1, 7 (38,8%) como HAstV-2 e 1 (5,5%) como HAstV-8. As amostras genotipadas em ambos os grupos foram submetidas ao seqüenciamento de nucleotídeos para confirmação dos resultados. Detecção e genotipagem de astrovírus em casos de diarréias pediátricas são técnicas são importantes e descrevem como esse vírus está circulando em São Paulo, Brasil. / The purpose of this study was to characterize astrovirus in faecal samples collected from children with and without diarrhea in São Paulo city, Brazil, and grouped into two distinct groups, EPM and HU. Detection was carried out using RT-PCR with specific primers. Results for EPM set showed that 66/234 (28,2%) were positive. In the HU set of samples, 18/187 (9,6%) were positive for astrovirus. Genotyping was carried out with nested/RT-PCR. Out of 66 astrovirus positive EPM samples, 19 (28,7%) were characterized as HAstV-1, 4 (6,0%) as HAstV-2, 2 (3,0%) as HAstV-3, 1 (1,5%) as HAstV-5 and 3 (4,5%) as HAstV-8. Among 18 astrovirus positive HU samples, 1 (5,5%) was characterized as HAstV-1, 7 (38,8%) as HAstV-2 and 1 (5,5%) as HAstV-8. Genotyped samples were confirmed by nucleotide sequencing. Detection and genotyping of astrovirus in pediatric diarrhea are important and describes how this virus is circulating in São Paulo, Brazil.
287

Bioanalítica de alicyclobacillus acidoterrestris : detecção em frutas cítricas, isolamento microbiológico e classificação filogenética por técnicas biomoleculares e eletroforese em microchips / Bioanalytical of alicyclobacillus acidoterrestris : detection in citric fruits, isolation microbiology and phylogenetic classification by biomolecular techniques and microchips electrophoresis\"

Huacca, Maribel Elizabeth Funes 18 April 2007 (has links)
Neste trabalho desenvolvemos métodos analíticos e moleculares para a detecção, isolamento e classificação filogenética de Alicyclobacillus spp. a partir de sucos de laranja e frutos ácidos, pelas técnicas: RT-PCR, nested RT-PCR, RAPD, seqüenciamento do 16S rRNA e análise por métodos eletroforéticos. A sensibilidade na detecção dos A. acidoterrestris foi melhorada por meio de reações de nested RT-PCR, utilizando primers internos (amplicon de 191 bp) que foram desenhados a partir do primeiro amplicom de 294 bp. O limite de detecção foi estudado com as reações RT-PCR e nested RT-PCR, sendo capazes de detectar concentrações de 0,1 UFC mL-1 para culturas puras e 2 UFC mL-1 em sucos de laranja artificialmente inoculados. A inibição de esporos de A. acidoterrestris também foi estudada para monitorar a diminuição da viabilidade com tratamento térmico e Sapindus saponaria (200 mg L-1), utilizando RT-PCR e nested RT-PCR. Com o tratamento térmico de 99 oC por 1 h o grau de inibição dos esporos foi de 96,3%. Enquanto que, com a fração purificada de S. saponaria (200 mg L-1) incubada à 45 oC por 2 dias foi de 93,6%, mas com incubação de 99 oC por 1 h foi de 98,7%, na mesma concentração de saponina. Todas as análises de quantificação de produtos de RT-PCR e nested RT-PCR foram analisadas por meio de eletroforese em gel de agarose e eletroforese capilar em microchip no Bioanalyzer 2100 (Agilent), com os kits DNA 500 e DNA 1000 LabChip®, obtendo-se maior sensibilidade nos microchips. A classificação molecular de dezenove cepas, isoladas a partir de diferentes sucos e frutos ácidos, foram estudadas utilizando RAPD-PCR e eletroforese capilar em microchips. Utilizando cinco primers aleatórios nas reações de RAPD, foi possível estudar os polimorfismos analisados nos microchips. Segundo as análises eletroforéticas, as cepas de suco concentrado e diluído de laranja (1, 2, 6) suco concentrado de limão (lim) e suco de laranja in natura (T2, T3), apresentaram similaridades genéticas com a A. acidoterrestris. O estudo de análise filogenética baseada na comparação de seqüências de DNA da região variável do gene 16S rRNA de Alicyclobacillus acidoterrestris, foi utilizado para identificar e agrupar onze cepas isoladas de superfícies e sucos de frutos ácidos. Na árvore filogenética gerada pelo método neighbor joining e bootstrap 1000x, as cepas analisadas mostraram similaridades de 99% entre todas elas, observando-se uma maior similaridade do controle A. acidoterretris (C2) com a cepa isolada de suco concentrado de limão (lim), e uma boa discriminação entre controles das espécies A. acidocaldarius, A. cicloheptanicus, A. sendaiensis e Sulfobacillus acidophilus. / In this work, we developed analytical and molecular methods for detection, isolation and phylogenetic classification of Alicyclobacillus spp. from orange juice and acid fruits using RT-PCR, nested RT-PCR, RAPD and sequencing of 16S rRNA techniques and electrophoretic methods of analysis. The sensitivity on the detection of A. acidoterrestris in orange juice was improved by nested RT-PCR, using internal primers (amplicon of 191 bp) that were designed after sequencing the first amplicon (294 bp). The detection limit was studied with RT-PCR and nested RT-PCR assay, it was able to detect concentrations of 0.1 UFC mL-1 for media culture and 2 UFC mL-1 in inoculated orange juice. The inhibition in spores from A. acidoterrestris was also studied to monitoring the diminution of viability with heat treatment and Sapindus saponaria (200 mg mL-1), using RT-PCR and nested RT-PCR assays. The inhibition by heat treatment at 99 oC for 1 h was 96.3%. However, incubation with S. saponaria at 45 oC for 2 days inhibited 93,6%, however, with incubation of 99 oC for 1 h was 98,7%, in the same concentration of saponin. The quantification of the RT-PCR and nested RT-PCR amplification product were accomplished by capillary electrophoresis in microchips using the Bioanalyzer 2100 in conjunction with the LabChip (TM) DNA 500 and DNA 1000. The molecular classification of nineteen strains isolated from different juice and acidic fruit, were studied using RAPD-PCR and capillary electrophoresis in microchips. Using five random primers in the RAPD assay, it was possible to study the polymorphisms analyzed in microchips. According to electrophoresis analyses, the strains from concentrated and diluted orange juices (1, 2, 6), lemon concentrated juice (lim) and natural orange juice (T2, T3), showed genetic similarities with the A. acidoterrestris. The study of the phylogenetic analyses based on DNA comparison sequences of the variable region of 16S rRNA gene from Alicyclobacillus acidoterrestris, was utilized for the identification and grouping of eleven strains isolated from surface and juice of acid fruits. In the phylogenetic tree produced by neighbor joining and bootstrap 1000, the strains showed similarities of 99% among all strains, showing a high similarity of A. acidoterrestris with a strain isolated from lemon concentrate juice (lim), and a good discrimination between the species A. acidocaldarius, A. cycloheptanicus, A. sendaiensis and Sulfobacillus acidophilus.
288

Paridade, desenvolvimento ovariano e transmissão vertical do vírus dengue em fêmeas de Aedes aegypti e Aedes albopictus (Diptera: Culicidae), na cidade de São Paulo / Parity ovarian development and vertical transmission of dengue virus in Aedes aegypti and Aedes albopictus (Diptera: Culicidae), in the city of São Paulo

Andrade, Pâmela dos Santos 19 September 2018 (has links)
No Brasil, a transmissão dos quatro sorotipos do vírus dengue ao homem ocorre através da picada da fêmea infectada de Aedes aegypti, também considerado vetor principal de outros arbovírus, como chikungunya e Zika. Além dessa espécie, o Aedes albopictus é considerado vetor potencial desses arbovírus. Populações brasileiras de Ae. aegypti e Ae. albopictus demonstraram a capacidade de realizar alguns repastos sanguíneos em diferentes hospedeiros dentro de um único ciclo de oviposição, o que chamamos de discordância gonotrófica. Paralelamente, a vigilância do DENV a partir de sua detecção em fêmeas de Ae. aegypti e Ae. albopictus que nunca se alimentaram de sangue é essencial para uma melhor compreensão da dinâmica de transmissão vertical desse agente etiológico. O objetivo desse estudo foi avaliar a paridade, a presença de sangue no estômago e o desenvolvimento ovariano de fêmeas de Ae. aegypti e de Ae. albopictus coletadas no Parque Esporte para Todos da Universidade de São Paulo - Cidade Universitária e na Faculdade de Saúde Pública da Universidade de São Paulo, bem como detectar DENV em fêmeas dessas espécies, oriundas de ovos coletados no Parque Municipal do Piqueri, São Paulo. Fêmeas de Ae. aegypti e Ae. albopictus capturadas tiveram o abdômen e ovários avaliados, através da técnica de dissecção. A investigação do RNA viral foi feita através de Transcrição Reversa seguida da Reação em Cadeia da Polimerase (RT-PCR). Foram encontrados 27% e 34% de fêmeas de Ae. aegypti e Ae. albopictus paridas, respectivamente, bem como 77% e 60% de fêmeas de Ae. aegypti e Ae. albopictus, respectivamente, com sangue no estômago. Foi constatado que 36% das fêmeas de Ae. aegypti estavam em discordância gonotrófica, enquanto essa taxa para Ae. albopictus foi de 27%. A transmissão vertical não foi detectada nas populações estudas. O campus da Faculdade de Saúde Pública e o Parque dos Esportes mostraram-se favoráveis para a manutenção e longevidade das duas espécies estudas. Apesar da transmissão vertical natural não ter sido detectada em nosso estudo, a investigação desse fenômeno é essencial para a compreensão da dinâmica de transmissão de arbovírus na natureza. / In Brazil, the transmission of the four serotypes of the dengue virus to human is transmitted out through the bite of the infected female of Aedes aegypti, it is also considered a vector of the main etiological agents of other arboviruses, such as chikungunya and Zika. In addition, Aedes albopictus is considered a potential arbovirus vector. Brazilian populations of Ae. aegypti and Ae. albopictus have already demonstrated an ability to perform some blood supply in different hosts within a single oviposition cycle, which we call gonotrophic discordance. At the same time, surveillance of the DENV from its detection in Ae. aegypti and Ae. albopictus that has never fed on blood is essential for a better understanding of the dynamics of vertical transmission of etiologic agent. The objective was to evaluate the parity, the presence of blood in the stomach and the ovarian development of Ae. aegypti and Ae. albopictus collected in the Parque Esporte para todos of Universidade de São Paulo - Cidade Universitária and Faculdade de Saúde Pública of Universidade de São Paulo, as well as detecting DENV in females of these species, from eggs collected in the Parque Municipal do Piqueri, São Paulo. Females of Ae. aegypti and Ae. albopictus captured, from the results obtained, through the technique of dissection. The investigation of the virus was done through Reverse Transcription followed by Polymerase Chain Reaction. We found 27% and 34% of Ae. aegypti and Ae. albopictus parous, 77% and 60% of Ae. aegypti and Ae. albopictus, respectively, with blood in the stomach. It was found that 36% of Ae. aegypti was in gonotrophic discordance, while that rate for Ae. albopictus was 27%. Vertical transmission was not detected in the selections studied. The campus of the Faculdade de Saúde Pública and the Parque Esporte para todos were favorable to the maintenance and longevity of the two species studied. Vertical nature transmission was not detected in our study, an investigation is an essential event for understanding the transmission of arbovirus data in nature.
289

Identificação in silico e perfil transcricional de genes candidatos a efetores de Austropuccinia psidii / In silico identification and transcriptional profile of effector candidate genes from Austropuccinia psidii

Lopes, Mariana da Silva 06 November 2017 (has links)
Austropuccinia psidii (sin Puccinia psidii) é um fungo biotrófico que infecta diversos gêneros de mirtáceas. É uma ferrugem (Puccinialles) nativa da América do Sul que apresenta ampla distribuição e rápida dispersão geográfica, alcançando atualmente a Austrália, centro de diversidade das mirtáceas. Este patógeno tem alarmado a comunidade científica devido à vasta capacidade de dispersão e por causar perdas econômicas consideráveis em culturas de interesse comercial, com destaque na eucaliptocultura. Apesar de sua importância, estudos relacionados ao patossistema A. psidii - Eucalyptus ainda são incipientes, sendo que o entendimento das bases moleculares envolvidas na interação planta-patógeno é essencial para adoção de medidas de controle eficazes e duradouras. Atualmente, a busca por candidatos a efetores tem crescido consideravelmente, pois são moléculas capazes de alterar a fisiologia do hospedeiro, suprimindo ou ativando os mecanismos de defesa. Dessa forma, o objetivo do presente estudo foi identificar in silico genes candidatos a efetores e validá-los por meio de análise de expressão por RT-qPCR. Para predição dos genes candidatos a efetores foi utilizado o genoma parcial de A. psidii e uma pipeline específica, baseada em diversos parâmetros, tais como: presença do peptídeo sinal, ausência de domínio transmembrana e superfície de ancoragem e pequeno tamanho. Foram identificados 2.886 candidatos, dos quais 13% apresentaram similaridade com Puccinialles. As categorias mais importantes de localização subcelular preditas foram apoplasto (87,3%), cloroplasto (7%) e núcleo (4,1%). Oito candidatos foram selecionados para análise de expressão após mineração em dados de RNA-seq. Os ensaios foram realizados in vitro com uredósporos de duas populações distintas de A. psidii, uma proveniente de eucalipto (MF-1) e outra de S. jambos (GM-J1) e as amostras foram coletadas em 6, 12 e 24 horas após inoculação (h.a.i). O perfil de expressão dos candidatos variou entre os tempos investigados, sendo que dois candidatos mostraram altos valores de expressão em todos os tempos, ao passo que quatro foram mais expressos nos tempos iniciais (6 e 12 h.a.i). Os tempos iniciais correspondem às fases de germinação e pré-penetração, fortalecendo a predição desses quatro candidatos como apoplásticos. Foi observado um perfil diferencial de expressão entre as duas populações do patógeno, o que sugere uma provável modulação pelo hospedeiro de origem na expressão dos candidatos a efetores, fato ainda pouco abordado na literatura e que deve ser melhor investigado. Embora o trabalho tenha sido realizado in vitro, foi possível selecionar potenciais candidatos para continuidade dos estudos, incluindo a validação in planta e caracterização funcional. Os dados são relevantes em vista a escassez de informações biológicas desse patossistema e fornecem uma visão inicial de como esses efetores atuam na interação planta-patógeno. / Austropuccinia psidii (sin Puccinia psidii) is a biotrophic fungus that infects several genera of Myrtaceae. It is a rust (Puccinialles) native from South America that displays a broad distribution after have shown a quick geographic dispersion, being currently present even in Australia, which is Myrtaceae\'s diversity center. This pathogen has alarmed the scientific community due to its wide dispersion ability and because of considerable economic losses occurring in crops of commercial interest, especially eucalyptus cultures. Despite its importance, studies related to A. psidii-Eucalyptus pathosystem are still incipient and the understanding of the molecular basis involved in the plant-pathogen interaction is essential to develop effective and durable control mechanisms. Currently, the search for effector candidates has increased considerably since they are molecules that alter the host physiology, suppressing or activating the defense mechanisms. In this study, we aimed to identify in silico effectors candidate genes and also to validate them by expression analysis (RT-qPCR). To predict the effector candidate genes, we used the partial genome of A. psidii and a specific pipeline based on several parameters, such as small size, presence of signal peptide, absence of transmembrane domain and anchorage surface. A total of 2,886 candidates were identified, from which 13% are similar to Puccinialles. The most important categories of predicted subcellular localization were apoplast (87,3%), chloroplast (7%) e nucleus (4,1%). Eight candidates were selected for expression analysis after mining in RNA-seq data. The in vitro assays were carried out with uredospores from two distinct populations of A. psidii: one from eucalyptus (MF-1) and other from S. jambos (GM-J1); the samples were collected 6, 12 and 24 hours after inoculation (h.a.i). The expression profile of the candidates was distinct among the times investigated. The results showed that two candidates had high expression values in all times evaluated, while four were more expressed at 6 and 12 h.a.i. These times correspond to the germination and pre-penetration phases, corroborating with the prediction of these four candidates as apoplastics. A differential expression profile was found between the two pathogen populations, suggesting a probable modulation by the origin host in the expression of effectors candidates, what has not been extensively investigated and discussed in the literature on the topic. Although this study has been performed in vitro, it was possible to select potential candidates for further investigations, including in plant validation and functional characterization. The data presented here are relevant considering the scarcity of biological information about this pathosystem, besides providing an initial insight on how these effectors act in the plant-pathogen interaction.
290

Pesquisa de infecções por Flavivirus sp. em aves silvestres provenientes das áreas verdes do município de São Paulo / Searching for Flavivirus infection in wild birds from São Paulo city green areas

Orico, Lilian Dias 26 August 2013 (has links)
INTRODUÇÃO: Em grandes cidades, como São Paulo, a pequena porcentagem de matas existentes é representada pelos parques municipais. Estas áreas, além de representarem ambientes de lazer para as pessoas, albergam uma enorme diversidade biológica, desde mosquitos até aves e mamíferos. A interação destas espécies favorece a circulação de Flavivirus, causadores de importantes doenças humanas, que têm nas aves um importante reservatório. Atribui-se às aves migratórias o papel de carreadoras dos vírus, já que as mesmas percorrem longas distâncias para completar seu ciclo biológico. A chegada de aves do Hemisfério Norte ocorre em alguns Parques, o que favoreceria a dispersão de alguns vírus, como o Vírus do Nilo Ocidental, já que nestas áreas estão presentes mosquitos potencialmente vetores. OBJETIVOS: identificar infecção por Flavivírus nas aves dos parques municipais de São Paulo. MÉTODOS: De Março de 2012 a Janeiro de 2013, foram coletadas amostras de swab de cloaca, orofaringe e sangue de aves capturadas em redes de neblina de duas áreas do município de São Paulo: Parque Anhanguera e Fazenda Castanheiras/APA Bororé Colônia. As aves foram anilhadas e liberadas após a coleta do material. Foi realizada técnica de RT-PCR em tempo real, utilizando iniciadores genéricos que amplificam fragmento do gene NS5 de Flavivirus. Amostras positivas foram encaminhadas para sequenciamento. RESULTADOS: Foi capturado um total de 231 aves, em sua maioria da Ordem Passeriformes. De um total de 463 amostras, nenhuma amostra apresentou presença de RNA viral. DISCUSSÃO: Em se tratando de alguns Flavivírus, os passeriformes são considerados os reservatórios mais competentes no ciclo de transmissão, pois atingem altos níveis de viremia. Cabe ressaltar que algumas espécies desta ordem, de ocorrência na cidade de São Paulo, já foram identificadas como portadoras dos vírus Rocio e Ilhéus. A ausência de positividade é esperada, pois embora altamente sensível, a técnica de PCR depende do estado de viremia das aves, que é curta. CONCLUSÃO: Os parques municipais são áreas que aproximam aves, mosquitos e humanos, pelo papel ambiental e de lazer que os mesmos representam. Este fato classifica estas áreas como locais com potencial de transmissão de Flavivirus, o que torna importante a continuação este estudo, aumentando as áreas de abrangência, para conhecer os Flavivírus circulantes e realizar vigilância para vírus que podem ocasionar problemas de Saúde Pública / INTRODUCTION: In big cities, as São Paulo, the little percentage of existing forests is represented by the municipal parks. These áreas, besides acting as entertainment environments to the users, promote a huge biodiversity, including mosquitoes, birds and mammals. These species interaction promotes Flavivirus circulation, viruses responsible for important human diseases. The avian species are important reservoirs for these viruses, specially the migrating birds that can fly for long distances, carrying these viruses to several areas. In some parks, the arrival of migrating birds from the North Hemisphere is documented, fact that can support some viruses dispersion, for example, the West Nile Vírus, considering that in these areas potencial vector for this virus can be found. OBJECTIVES: detect Flavivirus infection in birds captured in municipal parks of São Paulo city. METHODS: from March, 2012 to January, 2013, oropharyngeal and cloacal swabs, and blood samples were collected from birds captured in mist-net webs located in two municipal areas: Anhanguera Park and Castanheiras Farm/APA Bororé Colônia. The birds were ringed and released after samples collection. The real time RT-PCR was performed, using generic primers which amplify NS5 gene fragment. Positive samples were forwarded to sequence analysis. RESULTS: a total of 231 birds were capture, in which the majority belongs to Passeriforms order. Of 463 samples collected, all samples were negative for the viral RNA presence. DISCUSSION: when talking about Flaviviruses, the passeriforms are considered the most competent reservoirs in the transmission cycle, because they can achieve great viremia levels. Some passeriforms species, endemic in São Paulo city, were identified as Rocio and Ilhéus viruses carriers in previous studies. The negativity is expected, once the Real Time RT-PCR, although highly sensitive, depends on the viremia duration, which is short in avian species. CONCLUSION: the public parks are areas which encloses birds, mosquitoes and the human being, for the environmental and entertainment role they play. This fact classifies these parks as areas with great potencial of Flavivirus transmission, ressalting the great importance to continue this study, increasing the number of areas, to detect the circulating Flavivirus and to perform surveillance for viruses which can cause public health problems

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