Fur controls iron homeostasis and oxidative stress defense in the oligotrophic alpha-proteobacterium Caulobacter crescentus

In most bacteria, the ferric uptake regulator (Fur) is a global regulator that controls iron homeostasis and other cellular processes, such as oxidative stress defense. In this work, we apply a combination of bioinformatics, in vitro and in vivo assays to identify the Caulobacter crescentus Fur regulon. A C. crescentus fur deletion mutant showed a slow growth phenotype, and was hypersensitive to H2O2 and organic peroxide. Using a position weight matrix approach, several predicted Fur-binding sites were detected in the genome of C. crescentus, located in regulatory regions of genes not only involved in iron uptake and usage but also in other functions. Selected Fur-binding sites were validated using electrophoretic mobility shift assay and DNAse I footprinting analysis. Gene expression assays revealed that genes involved in iron uptake were repressed by iron-Fur and induced under conditions of iron limitation, whereas genes encoding iron-using proteins were activated by Fur under conditions of iron sufficiency. Furthermore, several genes that are regulated via small RNAs in other bacteria were found to be directly regulated by Fur in C. crescentus. In conclusion, Fur functions as an activator and as a repressor, integrating iron metabolism and oxidative stress response in C. crescentus

Fur controls iron homeostasis and oxidative stress defense in the oligotrophic alpha-proteobacterium Caulobacter crescentus

In most bacteria, the ferric uptake regulator (Fur) is a global regulator that controls iron homeostasis and other cellular processes, such as oxidative stress defense. In this work, we apply a combination of bioinformatics, in vitro and in vivo assays to identify the Caulobacter crescentus Fur regulon. A C. crescentus fur deletion mutant showed a slow growth phenotype, and was hypersensitive to H2O2 and organic peroxide. Using a position weight matrix approach, several predicted Fur-binding sites were detected in the genome of C. crescentus, located in regulatory regions of genes not only involved in iron uptake and usage but also in other functions. Selected Fur-binding sites were validated using electrophoretic mobility shift assay and DNAse I footprinting analysis. Gene expression assays revealed that genes involved in iron uptake were repressed by iron-Fur and induced under conditions of iron limitation, whereas genes encoding iron-using proteins were activated by Fur under conditions of iron sufficiency. Furthermore, several genes that are regulated via small RNAs in other bacteria were found to be directly regulated by Fur in C. crescentus. In conclusion, Fur functions as an activator and as a repressor, integrating iron metabolism and oxidative stress response in C. crescentus

Leaf Appearance and Elongation in Panicum maximum cv. Tanzania Tillers of Varying Ages

A sward may be considered as a tiller population of varying ages and sizes, and these different age groups are likely to present distinct behaviour in terms of growth and herbage production. However, there is very little information on how tiller age, in association with grazing management practices (e.g. frequency and intensity of grazing), alter morphogenetic characteristics and, therefore, herbage production. Against this background, the present experiment had the objective to evaluate leaf appearance and elongation in Panicum maximum cv. Tanzania tillers of different age groups when submitted to intermittent grazing regimes

Herbage Production of Tanzania Grass (\u3cem\u3ePanicum maximum\u3c/em\u3e cv. Tanzania) Submitted to Combinations of Frequencies and Intensities of Grazing by Cattle

Animal production from pastures is a complex process comprising three main stages: herbage growth, consumption by grazing animals and conversion into animal products (Hodgson, 1990). Utilisation is the stage where the grazier finds greater flexibility for management, probably because most processes related to harvest of the produced herbage by the grazing animals are very responsive to manipulation and control of defoliation practices. The objective of this study was to evaluate herbage production of a Panicum maximum cv. Tanzania pasture submitted to combinations of frequencies and intensities of grazing

Excess body fat negatively affects bone mass in adolescents

AbstractObjectiveThe aim of this study was to investigate the effects of excess body fat on bone mass in overweight, obese, and extremely obese adolescents.MethodsThis study included 377 adolescents of both sexes, ages 10 to 19 y. Weight, height, body mass index (BMI), bone age, bone mineral content (BMC), and bone mineral density (BMD) were obtained by dual-energy x-ray absorptiometry. The results were adjusted for chronological age and bone age. Comparisons according to nutritional classification were performed by analysis of variance, followed by Tukey test. Linear regression models were used to explain the variation in BMD and BMC in the L1–L4 lumbar spinal region, proximal femur, and whole body in relation to BMI, lean mass, fat mass (FM), and body fat percentage (BF%), considering P < 0.05.ResultsFor all nutritional groups, average bone age was higher than chronological age. In both sexes, weight and BMI values increased from eutrophic to extremely obese groups, except for BMD and BMC, which did not differ among male adolescents, and were smaller in extremely obese than in obese female adolescents (P < 0.01). Significant differences were observed for FM and BF% values among all nutritional groups (P < 0.01). Positive, moderate to strong correlations were detected between BMD and BMC for BMI, lean mass, and FM. A negative and moderate correlation was found between BMC and BF%, and between BMD and BF% at all bone sites analyzed in males and between BF% and spine and femur BMD, in females.ConclusionThe results reveal a negative effect of BF% on bone mass in males and indicate that the higher the BF% among overweight adolescents, the lower the BMD and BMC values

PRÁTICAS DE GESTÃO SUSTENTÁVEL E SEUS IMPACTOS. UMA ANÁLISE DO SETOR HOTELEIRO DA GRANDE VITÓRIA

Este artigo trata de como a sustentabilidade, sob a forma gerencial, está sendo empregada pelo setor hoteleiro da região metropolitana do Espirito Santo. O artigo descreve e analisa as práticas e impactos do gerenciamento sustentável na hotelaria regional, identifica ações concretas nesse âmbito, a vantagem obtida pelos hotéis, e as dificuldades para implantação desses métodos e modelos de gestão. Trata-se de uma pesquisa exploratória, de natureza qualitativa, obtida através de entrevista semiestruturada, aplicada a dois gestores de importantes hotéis da Grande Vitória, embasada nos estudos e teorias de Flores (1995), Hart (1997), Quinn (1996) e Souza (1993). A sustentabilidade é necessária para manutenção do planeta e economia mundial, e através da pesquisa foi possível compreender o foco dos gestores, o nível de importância dada ao assunto e o que fazer para melhorar esse cenário

Herbage Accumulation and Animal Performance on Xaraes Palisade Grass Subjected to Intensities of Continuous Stocking Management

The large majority of species used in Brazil belong to the Brachiaria and Panicum genus, with marandu paladisadegrass (Brachiaria brizantha (Hochst. ex A. Rich) cv. Marandu) being the main cultivated forage grass species (Santos Filho 1996). Brachiaria brizantha cv. xaraés (xaraes palisade grass) was released as an option for diversifying forage species, and it had the advantages of fast regrowth and herbage yield, favouring larger stocking rates and animal productivity (Euclides et al. 2008; 2009). The objective of this study was to evaluate herbage accumulation and animal performance of beef cattle steers grazing continuously stocked xaraes palisade grass managed at 15, 30 and 45 cm

Leishmaniose visceral canina em Barra de Guaratiba, Rio de Janeiro, Brasil: avaliação dos fatores de risco

Barra de Guaratiba é uma região litorânea da cidade do Rio de Janeiro onde a leishmaniose visceral americana é endêmica. Apesar das medidas de controle aplicadas nessa localidade, incluindo sacrifício de cães e borrifação de inseticidas, a soroprevalência canina está estimada em 25% e durante 1995 e 1997, 8 casos humanos autóctones foram notificados. Para avaliar fatores de risco relacionados com o aumento da infecção por Leishmania (Leishmania) chagasi em cães, nós examinamos 365 cães utilizando a técnica de Imunofluorescência Indireta (IFAT) e capturamos flebótomos em ambientes doméstico e peridoméstico. Algumas variáveis relacionadas à infecção foram avaliadas por análise uni e multivariada. A distância da residência a borda da floresta, sua altitude e presença do gambá Didelphis marsupialis no quintal, foram considerados fatores preditores da infecção por Leishmania (Leishmania) chagasiem cães de Barra de Guaratiba. A presença de Lutzomyia longipalpis em ambiente peridoméstico indica a possibilidade de ocorrência de novos casos humanos. Nossos dados também sugerem a presença de um ciclo enzoótico nessa localidade.Barra de Guaratiba is a coastal area of the city of Rio de Janeiro where American visceral leishmaniasis (AVL) is endemic. Although control measures including killing of dogs and use of insecticides have been applied at this locality, the canine seroprevalence remains at 25% and during 1995 and 1997 eight autochthonous human cases were notified. In order to evaluate factors related to the increase of the risk for Leishmania (Leishmania) chagasi infection in dogs we have screened 365 dogs by anti-Leishmania immunofluorescent antibody test (IFAT) and captured sandflies in the domestic and peridomestic environment. Some variables related to the infection were assessed by uni- and multivariate analysis. The distance of the residence from the forest border, its altitude and the presence of the opossum Didelphis marsupialis in the backyard, were found predictor factors for L. (L.) chagasi infection in dogs in Barra de Guaratiba. The presence of Lutzomyia longipalpis in the peridomestic environment indicates the possibility of appearence of new human cases. Our data also suggest the presence of a sylvatic enzootic cycle at this locality

Desenvolvimento de processos cromatográficos para retenção de amônia em água produzida- relatório final

A extração do petróleo em áreas offshore é, em geral, acompanhada de água de formação, originária do reservatório. Esta água tem características oleosas com um alto teor de sais o que constitui um sério problema ambiental. O nível de concentração de amônia nesta água é superior ao limite máximo permitido para descarte. A principal dificuldade na remoção de amônia da água produzida é o alto nível de íons sódio e a presença de muitos outros íons interferentes encontrados nesta água. Este relatório apresenta a consolidação do estudo da remoção de amônia de água produzida utilizando zeólitas e adsorventes comerciais