1000 resultados para colonização de raiz
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In the food industry, Salmonella sp. and other pathogens represent a major threat as potential causes of foodborne diseases. The Salmonella enterica serovar Heidelberg (SH) has a great importance to public health, being currently the most frequent serotype in the official control analyzes carried out in Brazil’s Southern. In this region are concentrated the largest poultry flocks, contributing over 60 % of Brazilian production of chicken meat. To help prevent and minimize infections by pathogenic bacteria, in addition to attend the standards of biosecurity in the field and good hygiene and sanitizing programs in the industry, there is the possibility to control directly on the poultry breeding. Use of organic acids added in the diet of the fowls has an antibacterial action. In the other hand, the use of probiotics has been shown to prevent enteric diseases. This dissertation was divided into two chapters and aimed to evaluate the quantitative and qualitative reduction of SH in broiler chickens. In the first chapter the aim was to collect information on the prevalence rate of SH strain in broiler chickens. This coefficient was 100 %, being a suitable method for determining the frequency of salmonellosis in broiler chickens. In the second chapter five treatments were evaluated (a positive control and four tests), in order to reduce the colonization of SH in broilers, using organic acids and probiotic during production phase. In SH count related to the colonization of the cecum at 28 days of age differences were observed (p<0,05) among treatments. The Treatment 2 showed a count of 41 most probable number of bacterial cells per gram (MPN/g) with lower counts when compared to the positive control (5.106 MPN/g) and treatment 1 (1.354 MPN/g). The evaluation index of infected birds, there was a difference between treatments. In treatment 2, and treatment 4 reduced 58,34 % and 25 % respectively the number of fowls infected with SH. There was no effect of treatments on the performance. Administration of organic acids and probiotic used in the treatment 2 proved to be an effective tool in the SH control in broilers at 28 days of age.
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A distribuição da espécie D. viscosa, nativa em Portugal, foi avaliada ao longo da berma de duas estradas, do sul do país. A composição florística e a percentagem de cobertura do solo das diferentes espécies foram amostradas em áreas de berma com e sem a influência de D. viscosa, para avaliar o seu efeito nas comunidades das bermas. O efeito do corte dos arbustos foi também estudado. A espécie em estudo apresentou uma clara preferência pelas bermas, comparativamente com as áreas envolventes. Os resultados sugerem que a presença dos arbustos provoca uma diminuição na biodiversidade das bermas. As estradas estudadas devem, portanto, ser alvo de controlo da distribuição desta espécie, para impedir a sua invasão. Com base nos resultados, sugerimos que o controlo deve ser efectuado através de dois cortes, no meio da primavera para impedir a propagação de incêndios e no final do verão, para prevenir a dispersão das sementes. ABSTRACT; The distribution of the native species D. viscosa was evaluated along the road verges of two roads in southern Portugal. The plant species composition and cover were surveyed within the roadside habitats, in areas with and without D. viscosa, to evaluate its effect on road verge communities. The effect of mowing on D. viscosa shrubs was also assessed. Shrubs showed a clear preference to verges relative to the surroundings, indicating that D. viscosa seems to be invading the study road verges. Results also suggest that the presence of the shrubs decrease the plant diversity of road sides, with potential effects on animals as well. Therefore, the study roads should be considered as important targets of local and regional efforts to prevent invasions of this species. Based on our results, we suggest that to prevent D. viscosa invasion within roadside ecosystems, the control should be based on two mowings, in mid-spring to prevent fires and in late-summer to prevent seed dispersal.
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O ácido chiquímico é um indicador da intoxicação das plantas por glifosate. Apesar de inativado no solo, há indícios de que esse herbicida pode ser liberado pelas raízes das plantas tratadas sendo, posteriormente, absorvido por outras plantas. O objetivo desse trabalho foi verificar a exsudação do glifosate a partir de plantas de soja RR e sua posterior absorção por soja convencional, ambas cultivadas em sistema hidropônico. Os resultados mostraram que houve exsudação do glifosate e de seu metabolito ácido aminometilfosfônico (AMPA) pela soja RR na solução nutritiva e posterior absorção do herbicida, indicada pelo acúmulo do ácido chiquímico nas plantas de soja convencional. Comprova-se a exsudação e posterior absorção do glifosate, entretanto, relacionar estes fatos com os efeitos negativos sobre o crescimento e o aumento da suscetibilidade das plantas às doenças é prematuro, principalmente devido à forte adsorção do produto. Há necessidade de estudos posteriores que relacionem fatores climáticos, balanço de massas além de microorganismos endofíticos e micorrizas.
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Tese (doutorado)—Universidade de Brasília, Instituto de Letras, Instituto de Letras, Departamento de Teoria Literária e Literaturas, Programa de Pós-Graduação em Literatura, 2016.
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2009
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Alrededor de los años noventa, Costa Rica experimentó una crisis en los precios de exportación del café. Esto motivo a que una parte del convenio de la Escuela de Ciencias Geográficas con la Universidad de Utrecht, bajo el Proyecto Causas y Consecuencias de los Desastres Naturales, se enrumbara hacia el análisis socio económico de los problemas que la crisis del café estaba causando en la región de Puriscal como región agrícola; el estudio debía comprender, también, la modificación del patrón espacial como producto del fenómeno. De tal manera, se ofrece el patrón espacial de este cultivo a través de algún tiempo, así como las transformaciones (reducciones según áreas) espaciales en el comportamiento del cultivo a raíz de la crisis.
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2016
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O presente artigo busca, através da categoria de formação sócio-espacial, associar a colonização germânica na Grande Florianópolis à gênese de circuitos produtivos voltados ao abastecimento alimentar da capital catarinense. Os circuitos regionais de Florianópolis, inicialmente baseados no tropeirismo entre o planalto e o litoral, adquirem com a colonização germânica, no século XIX, um maior volume e diversificação da produção. Com o aprofundamento da Divisão do Trabalho ao longo do século XX, o espaço agrário regional foi-se especializando na produção de alimentos com destino às áreas de concentração urbana. Estes circuitos regionais foram alterando sua configuração de acordo com as inovações do meio técnico-científico, encurtando as distâncias-tempo entre os lugares envolvidos no escoamento da produção; no entanto, os círculos de cooperação espacial pouco alteraram sua composição, onde um intermediário da localidade, detentor de capital e informação, realiza a transferência do produto se apropriando de parte da renda do produtor rural.
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O cultivo da mandioca tem um papel importante no Brasil, tanto como fonte de alimento, quanto como gerador de emprego e renda. A mandioca tem sua produção limitada pela incidência de doenças, como a podridão mole da raiz, que é uma doença limitadora. A obtenção de variedades resistentes é uma das formas de controle da doença e a identificação de características indicativas de resistência ao patógeno é uma ferramenta para auxiliar o melhoramento genético. O objetivo do trabalho foi verificar se características morfológicas do conjunto súber mais córtex da raiz de mandioca estão associados à resistência ou suscetibilidade à podridão mole. Foram avaliadas três variedades resistentes e cinco suscetíveis à doença. A coleta das amostras foi realizada no município de Igarapé-Açu no Estado do Pará. Foram realizadas medições súber+córtex e do xilema. Os resultados foram submetidos à análise de variância e as médias comparadas pelos testes de Scott-Knot (p>0,05).
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2016
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Spinocerebellar ataxia type 1 (SCA1), spinocerebellar ataxia type 2 (SCA2) and Machado-Joseph disease or spinocerebellar ataxia type 3 (MJD/SCA3) are three distinctive forms of autosomal dominant spinocerebellar ataxia (SCA) caused by expansions of an unstable CAG repeat localized in the coding region of the causative genes. Another related disease, dentatorubropallidoluysian atrophy (DRPLA) is also caused by an unstable triplet repeat and can present as SCA in late onset patients. We investigated the frequency of the SCA1, SCA2, MJD/SCA3 and DRPLA mutations in 328 Brazilian patients with SCA, belonging to 90 unrelated families with various patterns of inheritance and originating in different geographic regions of Brazil. We found mutations in 35 families (39%), 32 of them with a clear autosomal dominant inheritance. The frequency of the SCA1 mutation was 3% of all patients; and 6 % in the dominantly inherited SCAs. We identified the SCA2 mutation in 6% of all families and in 9% of the families with autosomal dominant inheritance. The MJD/SCA3 mutation was detected in 30 % of all patients; and in the 44% of the dominantly inherited cases. We found no DRPLA mutation. In addition, we observed variability in the frequency of the different mutations according to geographic origin of the patients, which is probably related to the distinct colonization of different parts of Brazil. These results suggest that SCA may be occasionally caused by the SCA1 and SCA2 mutations in the Brazilian population, and that the MJD/SCA3 mutation is the most common cause of dominantly inherited SCA in Brazil.
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The research approaches recycling of urban waste compost (UWC) as an alternative fertilizer for sugarcane crop and as a social and environmental solution to the solids residuals growth in urban centers. A mathematical model was used in order to know the metal dynamics as decision support tool, aiming to establish of criteria and procedures for UWC's safe use, limited by the amount of heavy metal. A compartmental model was developed from experimental data in controlled conditions and partially checked with field data. This model described the heavy metal transference in the system soil-root-aerial portion of sugarcane plants and concluded that nickel was metal to be concern, since it takes approximately three years to be attenuated in the soil, reaching the aerial portions of the plant at high concentrations. Regarding factors such as clay content, oxide level and soil pH, it was observed that for soil with higher buffering capacity, the transfer of the majority of the metals was slower. This model may become an important tool for the attainment of laws regarding the UWC use, aiming to reduce environment contamination the waste accumulation and production costs.
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The aim of this study was to analyse seed dispersal and establishment of Solanum thomasiifolium in an area of nativo vegetation in Espirito Santo state on the southeastern Brazilian coast. Ten species of birds, the crab-eating fox (Cerdocyon thous), and one species of lizard (Tropidurus torquatus) fed on S. thomasiifolium fruits and dispersed viable seeds in their faeces. The proportional contribution of each of these groups to seed dispersal was 77% (birds), 19% (crab-eating fox) and 4% (lizards). Ants also contributed to seed dispersal. More seeds were deposited in vegetation islands than in the surrounding open areas. Germination rates of seeds collected directly from fruit (control), bird droppings, the faeces of crab-eating foxes and lizards were, respectively, 64, 64, 53, and 80 %. Differences among these rates were all significant, except between birds and control. Lizards were important as seed carriers between nearby islands and they expelled a higher proportion of viable seeds. Birds and the crab-eating foxes did not enhance seed germination, but promoted seed dispersal over a wider area. Plant architecture, fruit productivity, fruit characteristics and the diversity of frugivores are important for the success of S. thomasiifolium in habitat colonization.
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Cuphea carthagenensis (Jacq.) J.F. Macbr. is an herb, which occurs preferably in wet places. Amongst other species of the genus, C. carthagenensis is distinguished for its great chemical potential and frequent use in popular medicine. In this study the morphological and anatomical structures were identified, as well as the histochemical characterization was done. Samples of root, stem and leaves were collected from adult plants. This material was processed for anatomical and histochemical analysis in light microscopy and for morphological analysis, in scanning electron microscopy. Important morphological and anatomical considerations were added for C. carthagenensis, such as: the occurrence of aerenchymatous phellem with suberized layers; the types of trichomes present in the vegetative organs, the characterization of secretory trichomes, as well as the secreted substances. The groups of secondary metabolites presents in the root, stem and leaf of C. carthagenensis with more intense histochemical reaction were: proanthocyanidins, phenolic compounds, acids polysaccharides (mucilage especially) and lipids.
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This work investigated the cytotoxic and genotoxic potential of water from the River Paraíba do Sul (Brazil) using Allium cepa roots. An anatomo-morphological parameter (root length), mitotic indices, and frequency of micronuclei were analysed. Eight bulbs were chosen at random for treatment for 24 to 120 hours with the River water collected in the years of 2005 and 2006 from sites in the cities of Tremembé and Aparecida (São Paulo state, Brazil). Daily measurements of the length of the roots grown from each bulb were carried out throughout the experiment. Mitotic index (MI) and frequency of micronuclei (MN) were determined for 2000 cells per root, using 3-5 root tips from other bulbs (7-10). Only in the roots treated with samples of the River water collected in 2005 in Tremembé city was there a decrease in the root length growth compared to the respective control. However, a reduction in MI values was verified for both sites analysed for that year. Considering the data involving root length growth and especially MI values, a cytotoxic potential is suggested for the water of the River Paraíba do Sul at Tremembé and Aparecida, in the year of 2005. On the other hand, since in this year the MN frequency was not affected with the river water treatments, genotoxicity is not assumed for the river water sampled at the aforementioned places.