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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.
1

Molecular genetic analysis of pollen irradiation as a means to isolate deletion mutants in Arabidopsis

Yang, Cai Yun January 2001 (has links)
No description available.
2

Embryogenesis and germination in Arabidopsis thaliana L

Mansfield, Stephen Gary January 1989 (has links)
No description available.
3

Molecular characterisation of the POLARIS locus of Arabidopsis

Casson, Stuart Anthony January 2000 (has links)
This study is concerned with the analysis of the AtEMl0l promoter trap line of Arabidopsis thaliana. AtEMl0l seedlings show GUS expression in the tips of both primary and lateral roots, and more weakly in the hypocotyl and cotyledons. GUS activity in mature plants is found variably in both rosette and cauline leaves, stem nodes and also siliques but not other floral organs. Active auxins rapidly upregulate whilst cytokinins downregulate GUS transcript levels. AtEMl0l roots are shorter than those of the wild-type, a phenotype which is putatively linked to elevated ethylene levels. AtEMl0l roots were also found to be hypersensitive to exogenous cytokinins. Root patterning is not affected, but cells distal to the elongation zone are shorter in the AtEMl0l line than the wild-type. The T-DNA in line AtEMl0l was found to have inserted in a small, low abundance gene named POLARIS, which encodes a putative 36 amino acid polypeptide, which does not share homology to any known genes. POLARIS shows unusual genome organisation, with its 5' end overlapping with the 3' end of an upstream gene. Upstream sequence, embedded within the upstream gene, when fused to GUS were able to direct expression in root tips whilst a longer fragment mimics the GUS expression of the AtEMl0l line. Retransformation of the AtEMl0l line with a wild-type allele of POLARIS was able to complement the mutant phenotype indicating that the T-DNA insertion into POLARIS is responsible for the AtEMlOl phenotype. Overexpression of POLRIS resulted in transgenic plants with reduced sensitivity to both cytokinins and ACC. The structure of the POLARIS locus and the potential role of POLARIS in regulating cytokinin-induced ethylene levels, with regards to the control of root growth, are discussed.
4

Variable Geometry Scramjet Combustor Cavity Multi-Dimensional Treatise for Performance Analysis

Sorensen, Andrew Liam 02 November 2021 (has links)
The abilities of Scramjets and Ramjets, in their respective operating ranges, are partially bridged by dual-mode Scramjets. The limitations of operation are due to making a static motor that is designed to function in both modes resulting in low and high speed restrictions. This study covers the analysis into the ability of morphing the combustor in a Scramjet to allow for expanded operational capacities through simple mechanisms. Through the restriction and expansion of combustor cavity volume, operational capabilities of the engine can, therefore, be modified to best match scenario requirements. Due to the engine's ability to match a wide variety of scenarios the limitations seen in that of the dual-mode Scramjet are avoided through the usage of a morphing combustor. From initial findings using the quasi-1D Canonical REactor Scramjet Simulation (CReSS) solver, progress was made to confirm results through the usage of Computational Fluid Dynamics (CFD). Prior analysis of the momentum balance between stages two and four of the simulated Scramjet engines, the results showed that the variable geometry matched or outperformed the baseline HiFiRE geometry. The analysis revealed points of Mach and altitude where certain combustor volumes demonstrated greater performance. This greater performance is only gained by the ability to tune the engine in flight to react to external factors as there is no dominant geometry for a given range of Machs and altitudes. This tuning allows for the usage of performance mapping to extract the greatest performance possible over a variety of conditions. Further, it allows for the project to be continuously expanded into mapping appropriate reactions to other initial conditions and stimuli. Using CFD modeling to perform a parametric study on the prior work allows for finer control and analysis of said initial conditions and the resulting flow paths in the variety of tested combustor volumes. From this a discussion is made in regards to the effectiveness of the prior CReSS based analysis of the novel approach. / Master of Science / The abilities of Scramjets and Ramjets (engines which contain no moving parts as the compression of the incoming air is accomplished by the speed at which they operate with the separating factor being that the scramjets internal flow does not go below supersonic speeds), in their respective operating ranges, are partially bridged by dual-mode Scramjets. Dual-mode Scramjets are scramjets which can function with both sub- and super-sonic internal flow speeds. This being below or above Mach 1 (343 m/s, 767.3 mph) respectively. The limitations of operation are due to making a static motor where the geometry does not change that is designed to function in both modes resulting in low and high speed restrictions. This study continues the analysis into the ability of morphing the combustor, the volume in which the air fuel mixture combusts, in a Scramjet to allow for expanded operational capacities through simple mechanisms. Through the restriction and expansion of combustor volume, operational capabilities of the engine can, therefore, be modified to best match scenario requirements. Due to the engine's ability to match a wide variety of scenarios the limitations seen in that of the dual-mode Scramjet are avoided through the usage of a morphing combustor where morphing in this case is a simple volume change equivalent to that of a slide whistle. From initial findings using the quasi-1D Canonical REactor Scramjet Simulation (CReSS) solver, progress was made to confirm results through the usage of Computational Fluid Dynamics (CFD). Prior analysis of the momentum balance between stages two and four of the simulated Scramjet engines, the results showed that the variable geometry matched or outperformed the baseline HiFiRE geometry. The analysis revealed points of Mach and altitude where certain combustor volumes demonstrated greater performance. This greater performance is only gained by the ability to tune the engine in flight to react to external factors as there is no dominant geometry for a given range of Machs and altitudes. This tuning allows for the usage of performance mapping to extract the greatest performance possible over a variety of conditions. Further, it allows for the project to be continuously expanded into mapping appropriate reactions to other initial conditions and stimuli. Using CFD modeling to perform a parametric study on the prior work allows for finer control and analysis of said initial conditions and the resulting flow paths in the variety of tested combustor volumes. From this a discussion is made in regards to the effectiveness of the prior CReSS based analysis of the novel approach.
5

Molecular and biochemical characterization of subtilisin-like proteases in Arabidopsis thaliana

Hamilton, John Michael Uwe January 2000 (has links)
Subtilisin-like proteases form a large group of serine proteases with diverse functions, including the specific processing of a variety of proproteins and prohormones, and are found in prokaryotic and eukaryotic organisms. The work in this thesis focuses mainly on the Aral2 subtilisin-like protease following its discovery in the filtrate of Arabidopsis cell suspension cultures. Evidence obtained by Southern blotting and database searching is presented for the existence of a large gene family encoding subtilisin-like proteases in the model plant Arabidopsis thaliana. There may be more than fifty members in this gene family. Three of the corresponding DNA sequences have been cloned by RT-PCR and used as probes in Northern analysis to investigate the tissue specificity of the gene transcripts. These three genes appear to be expressed to varying degrees in Arabidopsis leaf, stem, root and silique tissues. A 650bp cDNA fragment encoding the C-terminal portion of the Aral2 protease has been obtained by RT-PCR, ligated to the malE gene and overexpressed as a fusion protein in E. coli cells. Polyclonal antisera have been raised against a combination of the fusion protein and the Aral2 C-terminal protein purified after cleavage from the fusion protein using Factor Xa protease. Aral2 protein has been detected in Arabidopsis tissues, particularly in siliques and stems, by Western blotting using these antibodies. An apoplastic location has been ascribed to Aral2 protease by immunocytochemistry using electron microscopy. The mature Aral2 subtilisin-like protease has been purified to homogeneity from Arabidopsis cell suspension culture filtrate by ion exchange chromatography and hydrophobic interaction chromatography. The purified enzyme has an acidic pH optimum of approximately pH5.5, which is unusual for a plant subtilisin-like protease. Aral2 protease is relatively thermostable and is activated in the presence of Ca(^2+) ions. The known serine protease inhibitors phenylmethanesulphonyl fluoride (PMSF), 4-(2- aminoethyl) benzenesulphonyl fluoride (AEBSF) and diisopropyl fluorophosphates (DFP) have an inhibitory effect on the proteolytic activity of Aral2. Substrate specificity studies have been performed using artificial peptide substrates, native proteins and cell wall protein extracts from Arabidopsis cells.
6

Política Nacional de Fiscalização do Conjunto CFESS/CRESS: estudo da experiência do CRESS-Alagoas

Padilha, Taciana Martins 17 June 2013 (has links)
Made available in DSpace on 2016-04-29T14:16:22Z (GMT). No. of bitstreams: 1 Taciana Martins Padilha.pdf: 2479421 bytes, checksum: e805d7a945e4425e116014f52b466d07 (MD5) Previous issue date: 2013-06-17 / The choice of approach to the subject was due to the degree of importance it plays in relation to studies on the National Audit of both the Federal Council of Social Service as the Regional Councils of Social Service, which were based on the perspective of its historical significance, and social dimensions of affirmative principles, regulations and policies and disciplinary and pedagogical. Its range aimed at the formation of a critical Project Ethical-Political Social Worker in their daily work, since, being well articulated, these elements express the conception of this work. In order to arrive at such an understanding, we present a brief history articulated with the Brazilian Social Services, since its genesis (decade 30) until the 2000s. This social and historical hike was necessary for people to really understand the construction and the need of the National Audit of all CFESS / CRESS under the act professional Social Worker. Thus, in the mid-90s, there is a professional able to articulate both theoretical and methodological, ethical, political and technical-operational. And it is this perspective of affirmation Project Ethical-Political Social Worker who sees the need to incorporate a conscious and critical attitude in their daily work. The National Audit Committees materializes in Guidance and Control (COFI), installed in the Regional Councils of Social Service (CRESS), leading to advances in the defense and enhancement of the profession. Through this comes the realization that allows a pop theoretical maturity, ethics, politics and art in the practice of Social Work, aimed at consolidating the Project Ethical-Political spaces socio-occupational, whose challenge to position themselves critically expressions of social issues that reiterates social inequality, to reflect the conditions ethical-political, technical, operational and theoretical-methodological. This time, our intention was to stimulate a critical discussion and reflective of the theory / practice in social and occupational spaces, bringing the pop in an attempt to (re) consider the role that policy in everyday social worker. From the methodological point of view, work desk research analyzing the reports of the deliberations of the XXVI National Meeting set CFESS / CRESS, probation and supervision of activities of the Regional Council of Pernambuco, along with literature searches using several authors such as Netto, Iamamoto, Martinelli, Bridges, and Lyra Ozanira. On the other hand, also appealed to the interview instrument oral and / or written, with the development of script open questions in order to reap the answers. After hearing them, we move to the transcript of the responses, which were read, reread and, finally, compared with calls that the National Authority. The analysis of the material sought to follow in the footsteps of qualitative research: description, thematic analysis and interpretation, noticing a gap than advocates pop with the theory / practice in the professional Social Worker / A opção pela abordagem do tema se deu em função do grau de importância que ele exerce no tocante aos estudos sobre a Política Nacional de Fiscalização, tanto do Conselho Federal de Serviço Social quanto dos Conselhos Regionais de Serviço Social, os quais se basearam na perspectiva do seu significado histórico-social e nas dimensões afirmativa de princípios, normativas e disciplinadoras e políticas-pedagógicas. Seu alcance visou à formação de uma reflexão crítica do Projeto Ético-Político do Assistente Social em seu cotidiano profissional, uma vez que, estando bem articulados, estes elementos expressam a concepção deste profissional. Para que se chegasse a tal entendimento, apresentamos um breve histórico brasileiro articulado com o Serviço Social, desde a sua gênese (década 30) até chegar aos anos 2000. Este caminhar social e histórico se fez necessário para que se pudesse compreender a construção e a necessidade da Política Nacional de Fiscalização do conjunto CFESS/CRESS no âmbito do agir profissional do Assistente Social. Desse modo, em meados dos anos 90, surge um profissional capaz de articular as dimensões teórica-metodológica, ética-política e técnica-operativa. E é nessa perspectiva de afirmação do Projeto Ético-Político do Assistente Social que se vislumbra a necessidade da incorporação de uma atitude consciente e crítica em seu cotidiano de trabalho. A Política Nacional de Fiscalização materializa-se nas Comissões de Orientação e Fiscalização (COFI), instaladas nos Conselhos Regionais de Serviço Social (CRESS), levando ao avanço na defesa e valorização da profissão. Por meio disso, nasce a percepção de que a PNF permite uma maturidade teórica, ética, política e técnica no exercício profissional do Assistente Social, visando à consolidação do Projeto Ético-Político nos espaços sócio-ocupacionais, que tem como desafio se posicionar criticamente às expressões da questão social que reitera a desigualdade social, de modo a refletir às condições ética-política, técnica-operativa e teórica-metodológica. Desta feita, nossa intenção foi estimular uma discussão crítica-reflexiva da relação teoria/prática nos espaços sócio-ocupacionais, trazendo a PNF na tentativa de (re) pensar o papel dessa política no cotidiano do Assistente Social. Do ponto de vista metodológico, trabalhamos a pesquisa documental analisando relatórios de deliberações do XXVI Encontro Nacional do conjunto CFESS/CRESS, de supervisão de estágio e de atividades do Conselho Regional de Pernambuco, juntamente com pesquisas bibliográficas utilizando vários autores, tais como, Netto, Iamamoto, Martinelli, Pontes, Lyra e Ozanira. Por outro lado, recorremos também ao instrumento de entrevista oral e/ou escrita, com a elaboração de roteiro de perguntas abertas com a finalidade de colher as respostas. Após ouvi-los, passamos à transcrição das respostas, que foram lidas, relidas e, por fim, comparados com o que preconiza a Política Nacional de Fiscalização. A análise do material buscou seguir os passos da pesquisa qualitativa: descrição, análise temática e interpretação, percebendo um distanciamento do que preconiza a PNF com a relação teoria/prática no fazer profissional do Assistente Social
7

Investigation of the Metal Content in Cress Seedlings fed with increased Concentration of Lead & Iron Solutions

Burton, Nikita January 2020 (has links)
Metals are essential nutrients for plant health, but not all metals are necessary and can sometimes be harmful towards plants depending on factors such as species, elemental composition in the soil and concentration of a metal. Iron (Fe), which is one of the most abundant metals in the earth’s crust is also one the most important nutrients for plant growth, as it is responsible for metabolism. Lead (Pb) has been widely outspoken to be a harmful pollutant to plants and has been shown in studies to have an impact on a plant’s physiology and morphology. The aim of this study is to analyze whether Pb and Fe influence the metal content of Garden cress (Lepidium sativum). A solution of Pb with the following concentrations; 2.4 g/L, 1.2 g/L, 0.48 g/L, 0.24 g/L, 0.12 g/L, 0.048 g/L and 0.024 g/L were used. Another solution of Fe with the following concentrations; 0.56 g/L, 0.28 g/L, 0.11 g/L, 0.056 g/L, 0.028 g/L, 0.011 g/L and 0.0056 g/L were also used. Then a combined solution of both Pb- and Fe solution were mixed with a volume ratio of 1:1 corresponding to the following concentrations of lead and iron, respectively; 0.024/0.0056 g/L, 0.048/0.0112 g/L, 0.12/0.028 g/L, 0.24/0.056 g/L, 0.48/0.112 g/L, 1.2/0.28 g/L were used. A total of 29 different metal contents were analyzed, which include; Aluminum (Al), silver (Ag), Barium (Ba), Beryllium (Be), Bismuth (Bi), Cadmium (Cd), Cobalt (Co), Copper (Cu), Fe, gallium (Ga), potassium (K), lithium (Li), magnesium (Mg), manganese (Mn), Molybdenum (Mo), sodium (Na), nickel (Ni), Pb, rubidium (Rb), selenium (Se), strontium (Sr), tellurium (Te), thallium (Tl), uranium (U), vanadium (V), zinc (Zn). Before initial analysis, microwave plasma atomic emission spectrometry (MP-AES) was applied with a test sample to evaluate if the acidified digestion method used with nitric acid and hydrogen peroxide was successful enough to be used for the original experiment. It was successful, so the cress samples underwent the same digestion method and were analyzed with inductive coupled plasma mass spectrometry (ICP-MS). The results showed that Pb overall decreased most metal contents, while Fe seemed to generally maintain a constant metal content of most metals. Fe fed cress seemed to grow the healthiest in appearance compared to Pb fed cress which grew the worst. Mixed solution Pb and Fe cress fed grew worse than Fe fed cress, but better than Pb fed cress. The growth quality was the worst with Pb fed and the best for controlled water fed cress. For mixed Pb and Fe solution fed cress the plants seemed to share similar qualities of both Pb- and Fe solution fed cress, with better growth capabilities than Pb fed cress, but worse than Fe fed cress. The high dilution factor during the sample preparation led to the fact that some trace and ultra-trace elements could not be determined, since their contents were below LOD or LOQ. Adapting the sample preparation procedure to these low concentrations would be a further improvement.
8

Genomas de vírus de DNA de fita simples detectados em soros de suínos com síndrome multissistêmica do definhamento do suíno através de metagenômica / Single stranded DNA virus genomes identified in swine sera with porcine circovirus associated disease through metagenomic

Cerva, Cristine January 2017 (has links)
As doenças associadas ao circovírus suíno (DACS) causam impacto econômico negativo nos sistemas de criação de suínos no mundo todo. As perdas incluem tratamento da doença, mortalidade, bem como diminuição no desempenho dos animais. Uma das manifestações mais relevantes das DACS é a síndrome multissistêmica do definhamento dos suínos (SMDS). O principal agente patogênico na causa da SMDS é o circovírus suíno tipo 2 (PCV2), no entanto, estudos observacionais e experimentais demonstraram que outros agentes estão envolvidos na patogênese e manifestação dos sinais clínicos. O sequenciamento de alto desempenho aliado a metagenômica são ferramentas que tornam possível a identificação da microbiota total de uma determinada amostra, independentemente de cultivo dos microrganismos. Visando contribuir para o conhecimento dos possíveis vírus envolvidos na SMDS, o presente trabalho realizou o sequenciamento genético de alto desempenho de soros de suínos e posterior análise do metagenoma resultante. Foram utilizadas amostras de soro coletadas em 2008, de 16 suínos com sinais clínicos da SMDS, entre 80 e 100 dias de idade, em uma granja no interior do Rio Grande do Sul. Os dados revelaram sequências virais de PCV2, parvovírus suíno tipo 1 a 6 (PPV1-6), torque teno vírus de suínos (TTSuV) tipo 1b, k2a e k2b e vírus de DNA circular de fita simples codificador de proteína associada a replicação (CRESS). A ocorrência de PCV2, PPV1-5 e TTSuV já foi descrita em suínos com SMDS, portanto este estudo reforça resultados anteriores. O PPV6 foi recentemente descrito na China, Europa e Estados Unidos, e os estudos não relacionaram o vírus com nenhuma doença específica de suínos. Os CRESS já foram identificados em todos os continentes, em vários tipos de amostras, incluindo fezes de suínos, mas sem nenhuma conexão com doenças de animais. Portanto, este é o primeiro relato de PPV6 e CRESS em suínos apresentando sinais de SMDS. Porém estudos posteriores são necessários para poder atribuir relação entre PPV6 e CRESS no desenvolvimento da SMDS. / Porcine circovirus associated disease (PCVAD) is one of the causes of negative economic impact on pig farming systems described worldwide. Losses include expenditures with treatment, increased mortality rates, and decreased productivity. One of the most relevant manifestations of PCVAD is the post-weaning multisystemic wasting syndrome (PMWS). The main pathogen present in PMWS is porcine circovirus type 2 (PCV2). However, observational and experimental studies have shown that other agents may be involved in the pathogenesis and clinical manifestation. High-throughput sequencing combined with metagenomics analyses make it possible to identify the total microbiota in a given sample, regardless of microorganism culture. In order to contribute to the knowledge of the viruses involved in PMWS, the present study carried out the high-throughput sequencing of swine sera and subsequent analysis of the resulting metagenome. Sixteen serum samples collected in 2008 on a farm in Rio Grande do Sul, from 80 and 100 days old pigs with clinical signs of PMWS, were examined. Data revealed viral sequences of PCV2, porcine parvovirus type 1 through 6 (PPV1-6), torque teno sus virus (TTSuV) types 1b, k2a and k2b and circular replication-associated protein (Rep) encoding single-stranded (CRESS) DNA viruses. The occurrences of PCV2, PPV1-5 and TTSuV have already been described in pigs with PMWS, so this study reinforces previous results. PPV6 was recently described in China, Europe and the United States, and the studies did not correlate the virus to any specific disease. CRESS DNA viruses have been identified on all continents in various types of samples, including swine feces, but without any connection to animal diseases. The present study is the first report of PPV6 and CRESS in pigs presenting PMWS signals. However, further studies are necessary to be able to attribute the relationship between PPV6 and CRESS in the development of SMDS.
9

Pramonės įmonių teršalų vertinimas pasyviosios lichenoindikacijos, pasyvaus kaupimo ir biotestavimo metodais / Industrial company's pollution evaluation using passive Lichen Indication method, passive accumulation and biotesting methods

Žilinskaitė, Marija 13 June 2014 (has links)
Baigiamajame darbe tiriama pramonės įmonių tarša pasyviosios lichenoindikacijos, pasyvaus kaupimo ir biotestavimo metodais. Darbo objektas - tyrimo metu vertintos įmonių teritorijose ant medžių aptinkamos epifitinių kerpių rūšys, taip pat vertinama teršalų sklaida pagal sėjamosios pipirnės (Lepidium sativum L.) augimą ant kiminų (sugėrusių įmonių išmetamus oro teršalus) terpės. Darbo tikslas – įvertinti oro kokybę pramonės įmonių teritorijose pagal ten aptinkamas epifitinių kerpių rūšis ir sėjamosios pipirnės (Lepidium sativum L.) augimą bei gautus rezultatus palyginti su pasyviųjų kaupiklių rezultatais. Darbo metodai – tyrimai buvo atliekami 2013-2014 metais didžiausias teršalų koncentracijas Šakių rajone išleidžiančių įmonių: UAB „Idavang“ ir UAB „Kriūkų baldai“ teritorijose. Tyrimo vietose 100 m, 200 m ir 500 m atstumais nuo taršos šaltinių buvo vertinamos ant medžių aptiktos epifitinių kerpių rūšys, kiekvienos rūšies padengimas procentais ir poleotolerantiškumo indeksas, taip pat vertintas biotestinio organizmo sėjamosios pipirnės (Lepidium sativum L.) augimas kiminų (augusių taršos šaltinių zonose) terpėje bei azoto dioksido koncentracijos iš pasyviųjų kaupiklių. Darbo rezultatai. Tyrimo objektų teritorija pasižymi nedidele kerpių gausa. Iš viso identifikuota 17 skirtingų kerpių rūšių abiejų tyrimo objektų teritorijose: 5 krūmiškosios, 8 lapiškosios ir 4 žiauberiškosios. Tiek UAB „Idavang“, tiek UAB „Kriūkų baldai“ teritorijose tolstant nuo taršos šaltinio... [toliau žr. visą tekstą] / In this thesis industrial company's pollution is investigated using passive Lichen Indication method, passive accumulation and biotesting methods. Object of research: Two species of plants were selected: garden cress (Lepidium sativum L.) and epiphytic lichen. During the evaluation we examined epiphytic lichen found on trees surrounding the territories of industrial companies and evaluated pollution dispersion by the growth of garden crass (Lepidium sativum L.) on sphagnum (which have absorbed the air pollutants produced by the companies) seedbed. Aim of the research: The aim of this research is to evaluate the air quality in the territories of industrial companies by the types of epiphytic lichen found in the perimeter and the spread of garden cress (Lepidium sativum L.) on sphagnum (which have absorbed the air pollutants produced by the companies) seedbed. Methods. The evaluation took place in year 2013-2014 in the territories of the most polluting companies in Šakiai district: UAB “Indavang” and UAB “Kriūkių baldai”. At distances of 100, 200 and 500 meters from the pollution source different types of epiphytic lichen were examined, as well as their coverage in percents and polio tolerance index. Both biotest organism's garden crass (Lepidium sativum L.) growth in sphagnum seedbed (growing in the pollution source territory) and nitrogen dioxide concentration from passive accumulators were evaluated. Results. Territories evaluated in this research have a small... [to full text]
10

Genomas de vírus de DNA de fita simples detectados em soros de suínos com síndrome multissistêmica do definhamento do suíno através de metagenômica / Single stranded DNA virus genomes identified in swine sera with porcine circovirus associated disease through metagenomic

Cerva, Cristine January 2017 (has links)
As doenças associadas ao circovírus suíno (DACS) causam impacto econômico negativo nos sistemas de criação de suínos no mundo todo. As perdas incluem tratamento da doença, mortalidade, bem como diminuição no desempenho dos animais. Uma das manifestações mais relevantes das DACS é a síndrome multissistêmica do definhamento dos suínos (SMDS). O principal agente patogênico na causa da SMDS é o circovírus suíno tipo 2 (PCV2), no entanto, estudos observacionais e experimentais demonstraram que outros agentes estão envolvidos na patogênese e manifestação dos sinais clínicos. O sequenciamento de alto desempenho aliado a metagenômica são ferramentas que tornam possível a identificação da microbiota total de uma determinada amostra, independentemente de cultivo dos microrganismos. Visando contribuir para o conhecimento dos possíveis vírus envolvidos na SMDS, o presente trabalho realizou o sequenciamento genético de alto desempenho de soros de suínos e posterior análise do metagenoma resultante. Foram utilizadas amostras de soro coletadas em 2008, de 16 suínos com sinais clínicos da SMDS, entre 80 e 100 dias de idade, em uma granja no interior do Rio Grande do Sul. Os dados revelaram sequências virais de PCV2, parvovírus suíno tipo 1 a 6 (PPV1-6), torque teno vírus de suínos (TTSuV) tipo 1b, k2a e k2b e vírus de DNA circular de fita simples codificador de proteína associada a replicação (CRESS). A ocorrência de PCV2, PPV1-5 e TTSuV já foi descrita em suínos com SMDS, portanto este estudo reforça resultados anteriores. O PPV6 foi recentemente descrito na China, Europa e Estados Unidos, e os estudos não relacionaram o vírus com nenhuma doença específica de suínos. Os CRESS já foram identificados em todos os continentes, em vários tipos de amostras, incluindo fezes de suínos, mas sem nenhuma conexão com doenças de animais. Portanto, este é o primeiro relato de PPV6 e CRESS em suínos apresentando sinais de SMDS. Porém estudos posteriores são necessários para poder atribuir relação entre PPV6 e CRESS no desenvolvimento da SMDS. / Porcine circovirus associated disease (PCVAD) is one of the causes of negative economic impact on pig farming systems described worldwide. Losses include expenditures with treatment, increased mortality rates, and decreased productivity. One of the most relevant manifestations of PCVAD is the post-weaning multisystemic wasting syndrome (PMWS). The main pathogen present in PMWS is porcine circovirus type 2 (PCV2). However, observational and experimental studies have shown that other agents may be involved in the pathogenesis and clinical manifestation. High-throughput sequencing combined with metagenomics analyses make it possible to identify the total microbiota in a given sample, regardless of microorganism culture. In order to contribute to the knowledge of the viruses involved in PMWS, the present study carried out the high-throughput sequencing of swine sera and subsequent analysis of the resulting metagenome. Sixteen serum samples collected in 2008 on a farm in Rio Grande do Sul, from 80 and 100 days old pigs with clinical signs of PMWS, were examined. Data revealed viral sequences of PCV2, porcine parvovirus type 1 through 6 (PPV1-6), torque teno sus virus (TTSuV) types 1b, k2a and k2b and circular replication-associated protein (Rep) encoding single-stranded (CRESS) DNA viruses. The occurrences of PCV2, PPV1-5 and TTSuV have already been described in pigs with PMWS, so this study reinforces previous results. PPV6 was recently described in China, Europe and the United States, and the studies did not correlate the virus to any specific disease. CRESS DNA viruses have been identified on all continents in various types of samples, including swine feces, but without any connection to animal diseases. The present study is the first report of PPV6 and CRESS in pigs presenting PMWS signals. However, further studies are necessary to be able to attribute the relationship between PPV6 and CRESS in the development of SMDS.

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