Effects of nitrate concentration on larval development of the giant river prawn, Macrobrachium rosenbergii

The effect of nitrate concentration on giant river prawn, Macrobrachium rosenbergii, larvae was investigated. Survival rate, weight gain, and larval development were evaluated for different concentrations of nitrate in three experiments. The experiments were divided i n to two phases. In the first phase, larvae from stages I through VIII were analysed, while in the second phase larvae from stage VIII through post-larvae metamorphosis were analysed. Oxygen consumption was also determined for zoea I, II, and VIII exposed to 0, 700, and 1,000 mg/L of nitrate-N. No effect was observed for concentrations up to 180 mg/L NO3-N (experiments I and II), and nitrate levels as 1,000 mg/L NO3-N did not affect survival in the first phase of the third experiment. On the other hand, larval stage index (LSI) and weight gain decreased as nitrate-N concentration increased from 0 to 1,000 mg/L. In the second phase, survival and metamorphosis rate decreased as nitrate concentration increased, according to a linear model. The effect of nitrate levels on weight gain followed a curvilinear pattern. Larval respiration decreased in the water where nitrate was added, but only during stage II. The results demonstrated that nitrate presents extremely low toxicity for giant river prawn larvae, and data were related to the levels of nitrate that usually occur in larviculture systems also discussed. Therefore, nitrate is not a limiting factor for giant river prawn larviculture. © 2003 by The Haworth Press, Inc. All rights reserved.

Water table effects on bean yield and nitrate distribution in the soil profile

In order to evaluate the bean yield under different water table levels as well as the moisture and nitrate distribution in the soil profile, a field experiment was carried out at the experimental area from the College of Agronomic Sciences - UNESP, Botucatu, SP, Brazil. Beans were grown in field lysimeters and subjected to five water table depths:30; 40; 50; 60 and 70 cm. The moisture in the soil profile was gravimetrically determined through samples obtained at 10; 20; 30; 40; 50; 60 and 70cm of depth. The water table depths of 30cm and 40cm showed the highest productivities (3,228.4 kg.ha-1 and 3,422.1 kg.ha-1, respectively), showing no statistical differences between each other. The highest productivity was related to the two most elevated water table levels (30 and 40cm), which provided the highest moisture average values on basis of volume in the soil profile (33.3 e 31%) as well as the consumptive use of water (416 and 396 mm). The nitrate content during the bean cycle at the extraction depth of 60cm has been under the safe drinking limit of 10 mg.1-1 for water table depths of 30; 40; 50 and 60cm, showing the denitrification effectiveness as a way of controlling water table from nitrate pollution. The water table handling allowed the attainment of high bean productivity levels, as well as the reduction of the nitrate level.

Water quality and plankton populations in an earthen polyculture pond

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Role of brain nitric oxide in the thermoregulation of broiler chicks

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Adubação nitrogenada em cobertura no feijoeiro com suplementação de molibdênio via foliar

The objective of this work was to evaluate the effect of leaf spray of molybdenum (Mo) and nitrogen (N) rates in common bean (Phaseolus vulgaris L.), cultivar Carioca Precoce, evaluating the yield components, yield and leaves nitrate levels. The research was carried out in Botucatu, State of São Paulo, Brazil. The sowing of the beans (06/03/2003) was made with the supply of 230 kg ha(-1) of NPK (4-30-10) granulated fertilizer at planting. The experiment was a complete randomized block, with four replications and a 5 x 2 factorial arrangement, involving five N rates (25; 50; 75 and 125 kg ha(-1)), applied 20 days after emergency (DAE), with or without 80 g ha(-1) of Mo, applied on leaves at 25 DAE. The Mo absence by leaf spray promoted the nitrate accumulation in the leaves in treatments with higher rates of N. The weight of 100 grains increased with the Mo by leaf spray, reducing the need for N to get the best results. The molybdenum fertilization increased bean yield regardless of N rate applied to the beans.

Exercise Training and Caloric Restriction Prevent Reduction in Cardiac Ca2+-Handling Protein Profile in Obese Rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Prevalência de dislipidemia em adultos de meia-idade com polimorfismo do gene NOS3 e baixa aptidão cardiorrespiratória

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reactivity of mesenteric and aortic rings from trained rats fed with high caloric diet

A strong association between the benefits of physical exercise on the cardiovascular disease with an improvement of the endothelium-derived relaxing factor production has been consistently shown. The purpose of this study was to evaluate the effect of exercise training associated with high caloric diet in the reactivity of rat mesenteric and aortic rings. Experimental protocol consisted of 4 weeks of high caloric diet consumption previous to 4 weeks of run training (1.2 km/h, 0% grade, in sessions of 60 min, 5 days/week). Concentrations of triglycerides, glucose, insulin and nitrite/nitrate levels were measured and atherogenic index was calculated. Concentration-response curves to acetylcholine (10 nM-100 mu M), sodium nitroprusside (100 pM-100 nM) and phenylephrine (1 nM-3 mu M) were obtained. Exercise training reduced body mass (6%) and triglyceride levels (about 54%), without changes in glucose and insulin concentrations. An improvement of endothelium-dependent relaxation responses to acetylcholine in mesenteric and aortic rings was observed in trained group. No changes were seen for sodium nitroprusside and phenylephrine. In conclusion, our study is the first to show clearly that run training promotes an improvement of the endothelium-dependent relaxing response in aorta and mesenteric rings from rats fed with high caloric diet and that is associated with increase of NO production. (c) 2006 Elsevier B.V. All rights reserved.

Doses de N-Ureia e de esterco bovino na qualidade nutricional da alface em consórcio com a rúcula

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Antioxidante em vegetais pós-colheira de origem orgânica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Soil nitrogen dynamics after Brachiaria desiccation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of 6-months of physical exercise on the nitrate/nitrite levels in hypertensive postmenopausal women

Background: Evidences have showed that the incidence of arterial hypertension is greater in postmenopausal women as compared to premenopausal. Physical inactivity has been implicated as a major contributor to weight gain and abdominal obesity in postmenopausal women and the incidence of cardiovascular disease increases dramatically after menopause. Additionally, more women than men die each year of coronary heart disease and are twice as likely as men to die within the first year after a heart attack. A healthy lifestyle has been strongly associated with the regular physical activity and evidences have shown that physically active subjects have more longevity with reduction of morbidity and mortality. Nitric oxide (NO) produced by endothelial cells has been implicated in this beneficial effect with improvement of vascular relaxing and reduction in blood pressure in both laboratory animals and human. Although the effect of exercise training in the human cardiovascular system has been largely studied, the majority of these studies were predominantly conducted in men or young volunteers. Therefore, the aim of this work was to investigate the effects of 6 months of dynamic exercise training (ET) on blood pressure and plasma nitrate/nitrite concentration (NOx-) in hypertensive postmenopausal women. Methods: Eleven volunteers were submitted to the ET consisting in 3 days a week, each session of 60 minutes during 6 months at moderate intensity (50% of heart rate reserve). Anthropometric parameters, blood pressure, NOx- concentration were measured at initial time and after ET. Results: A significant reduction in both systolic and diastolic blood pressure values was seen after ET which was accompanied by markedly increase of NOx- levels (basal: 10 ± 0.9; ET: 16 ± 2 μM). Total cholesterol was significantly reduced (basal: 220 ± 38 and ET: 178 ± 22 mg/dl), whereas triglycerides levels were not modified after ET (basal: 141 ± 89 and ET: 147 ± 8 mg/dl). Conclusion: Our study shows that changing in lifestyle promotes reducftion of arterial pressure which was accompanied by increase in nitrite/nitrate concentration. Therefore, 6-months of exercise training are an important approach in management arterial hypertension and play a protective effect in postmenopausal women. © 2009 Zaros et al; licensee BioMed Central Ltd.

Development and application of an electronic tongue for detection and monitoring of nitrate, nitrite and ammonium levels in waters

This work presents the first study and development of an electronic tongue analysis system for the monitoring of nitrogen stable species: nitrate, nitrite and ammonium in water. The electronic tongue was composed of an array of 15 potentiometric poly(vinyl chloride) membrane sensors sensitive to cations and anions plus an artificial neural network (ANN) response model. The building of the ANN model was performed in a medium containing sodium, potassium, and chloride as interfering ions, thus simulating real environmental samples. The correlation coefficient in the cross-validation of nitrate, nitrite and ammonium was satisfactory in the three cases with values higher than 0.92. Finally, the utility of the proposed system is shown in the monitoring of the photoelectrocatalytic treatment of nitrate. © 2013 Elsevier B.V.

Cover crops affecting levels of ammonium and nitrate in the soil and upland rice development

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)