62 research outputs found

    Agronomic evaluation of varieties of sugar cane inoculated with diazotrophic bacteria and fertilized with nitrogen

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    O objetivo deste trabalho foi avaliar a eficiência da inoculação de bactérias diazotróficas e da adubaçãonitrogenada, em duas variedades de cana‑de‑açúcar, cultivadas nas mesmas condições edafoclimáticas. O experimento foi conduzido durante os anos agrícolas de 2006/2007 e 2008/2009, em delineamento experimental de blocos ao acaso, com quatro repetições, instalado em março de 2006 em área de cultivo comercial, no Município de Campos dos Goytacazes, RJ. Os tratamentos foram: inoculação com bactérias diazotróficas, adubação com 120 kg ha‑1 de N, e o controle sem inoculação e sem adubação com nitrogênio. As variedades de cana‑de‑açúcar avaliadas foram RB72454 e RB867515. O inoculante continha estirpes de cinco espécies de bactérias diazotróficas. Foram feitas avaliações quanto à produtividade de colmos frescos, ao acúmulo de matéria seca total, ao N total da parte aérea e quanto à abundância natural de 15N do N disponível no solo e na cana‑de‑açúcar. As variedades apresentaram comportamentos distintos com os tratamentos, em que a RB867515 foi responsiva e a RB72454 não responsiva àinoculação e à adubação nitrogenada. Na variedade RB867515, o crescimento e o acúmulo de N total na parte aérea das plantas, promovidos pela inoculação, foram similares aos do tratamento com adubação nitrogenada.The objective of this work was to evaluate the efficiency of inoculation with diazotrophic bacteria and nitrogen fertilization, in two varieties of sugarcane grown under the same edaphic and climatic conditions. The experiment was carried out during the agricultural years 2006/2007 and 2008/2009, in a randomized block design with four replicates, installed in March 2006 in an area of commercial cultivation in Campos dos Goytacazescity, in Rio de Janeiro state, Brazil. The treatments were: inoculation with diazotrophic bacteria, fertilization with120 kg ha‑1 N, and a control without inoculation and without nitrogen fertilization. The sugarcane varieties evaluated were RB72454 and RB867515. The inoculant was composed of five strains of diazotrophic bacteria. Evaluations were done for fresh stalk yield, total dry matter accumulation, total N of shoots, and 15N natural abundance from available N in the soil and in sugarcane. The varieties performed differently to treatments, in which RB867515 was responsive and RB72454 unresponsive to inoculation and nitrogen fertilization. In the variety RB867515, growth and accumulation of total N in the shoots, promoted by inoculation, were similar to the ones in the treatment with N fertilization

    Modulating an oxidative-inflammatory cascade: potential new treatment strategy for improving glucose metabolism, insulin resistance, and vascular function

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    Type 2 diabetes is a result of derangement of homeostatic systems of metabolic control and immune defense. Increases in visceral fat and organ adipose, environmental factors and genetic predisposition create imbalances of these homeostatic mechanisms, ultimately leading to a condition in which the oxidative environment cannot be held in check. A significant imbalance between the production of reactive oxygen species and antioxidant defenses, a condition called to oxidative stress, ensues, leading to alterations in stress-signalling pathways and potentially end-organ damage. Oxidative stress and metabolic inflammation upregulate the expression pro-inflammatory cytokines, including tissue necrosis factor alpha, monocyte chemoattractant protein-1 and interleukin-6, as well as activating stress-sensitive kinases, such as c-Jun N-terminal kinase (JNK), phosphokinase C isoforms, mitogen-activated protein kinase and inhibitor of kappa B kinase. The JNK pathway (specifically JNK-1) appears to be a regulator that triggers the oxidative-inflammation cascade that, if left unchecked, can become chronic and cause abnormal glucose metabolism. This can lead to insulin resistance and dysfunction of the vasculature and pancreatic β-cell. The series of events set in motion by the interaction between metabolic inflammation and oxidative stress constitutes an ‘oxidative-inflammatory cascade’, a delicate balance driven by mediators of the immune and metabolic systems, maintained through a positive feedback loop. Modulating an oxidative-inflammation cascade may improve glucose metabolism, insulin resistance and vascular function, thereby slowing the development and progression to cardiovascular diseases and type 2 diabetes

    Indicators of "Healthy Aging" in older women (65-69 years of age). A data-mining approach based on prediction of long-term survival

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    <p>Abstract</p> <p>Background</p> <p>Prediction of long-term survival in healthy adults requires recognition of features that serve as early indicators of successful aging. The aims of this study were to identify predictors of long-term survival in older women and to develop a multivariable model based upon longitudinal data from the Study of Osteoporotic Fractures (SOF).</p> <p>Methods</p> <p>We considered only the youngest subjects (<it>n </it>= 4,097) enrolled in the SOF cohort (65 to 69 years of age) and excluded older SOF subjects more likely to exhibit a "frail" phenotype. A total of 377 phenotypic measures were screened to determine which were of most value for prediction of long-term (19-year) survival. Prognostic capacity of individual predictors, and combinations of predictors, was evaluated using a cross-validation criterion with prediction accuracy assessed according to time-specific AUC statistics.</p> <p>Results</p> <p>Visual contrast sensitivity score was among the top 5 individual predictors relative to all 377 variables evaluated (mean AUC = 0.570). A 13-variable model with strong predictive performance was generated using a forward search strategy (mean AUC = 0.673). Variables within this model included a measure of physical function, smoking and diabetes status, self-reported health, contrast sensitivity, and functional status indices reflecting cumulative number of daily living impairments (HR ≥ 0.879 or RH ≤ 1.131; P < 0.001). We evaluated this model and show that it predicts long-term survival among subjects assigned differing causes of death (e.g., cancer, cardiovascular disease; P < 0.01). For an average follow-up time of 20 years, output from the model was associated with multiple outcomes among survivors, such as tests of cognitive function, geriatric depression, number of daily living impairments and grip strength (P < 0.03).</p> <p>Conclusions</p> <p>The multivariate model we developed characterizes a "healthy aging" phenotype based upon an integration of measures that together reflect multiple dimensions of an aging adult (65-69 years of age). Age-sensitive components of this model may be of value as biomarkers in human studies that evaluate anti-aging interventions. Our methodology could be applied to data from other longitudinal cohorts to generalize these findings, identify additional predictors of long-term survival, and to further develop the "healthy aging" concept.</p
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