Baclofen into the lateral parabrachial nucleus induces hypertonic sodium chloride and sucrose intake in rats

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

Central nitrergic system regulation of neuroendocrine secretion, fluid intake and blood pressure induced by angiotensin-II

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

An Arabidopsis Mitochondrial Uncoupling Protein Confers Tolerance to Drought and Salt Stress in Transgenic Tobacco Plants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Interaction between paraventricular nucleus and septal area in the control of physiological responses induced by angiotensin II

We determined the effects of losartan (40 nmol) and PD 123319 (40 nmol) (both non-peptides and selective antagonists of the AT1 and AT2 angiotensin receptors, respectively), and [Sar¹, Ala8] angiotensin II (ANG II) (40 nmol) (a non-selective peptide antagonist of angiotensin receptors) injected into the paraventricular nucleus (PVN) on the water and salt appetite, diuresis and natriuresis and mean arterial pressure (MAP) induced by administration of 10 nmol of ANG II into the medial septal area (MSA) of male Holtzman rats weighing 250-300 g. The volume of drug solution injected was 0.5 µl over a period of 10-15 s. The responses were measured over a period of 120 min. ANG II alone injected into the MSA induced an increase in all the above parameters (8.1 ± 1.2, 1.8 ± 0.3, and 17.1 ± 1.0 ml, 217 ± 25 µEq/120 min, and 24 ± 4 mmHg, respectively, N = 10-12) compared with vehicle-treated rats (1.4 ± 0.2, 0.6 ± 0.1, and 9.3 ± 0.5 ml, 47 ± 5 µEq/120 min, and 4.1 ± 0.8 mmHg, respectively, N = 10-14). Pretreatment with losartan and [Sar¹, Ala8] ANG II completely abolished the water and sodium intake, and the pressor increase (0.5 ± 0.2, 1.1 ± 0.2, 0.5 ± 0.2, and 0.8 ± 0.2 ml, and 1.2 ± 3.9, 31 ± 4.6 mmHg, respectively, N = 9-12), whereas losartan blunted the urinary and sodium excretion induced by ANG II (13.9 ± 1.0 ml and 187 ± 10 µEq/120 min, respectively, N = 9). Pretreatment with PD 123319 and [Sar¹, Ala8] ANG II blocked the urinary and sodium excretion (10.7 ± 0.8, 9.8 ± 0.7 ml, and 67 ± 13 and 57 ± 17 µEq/120 min, respectively, N = 9), whereas pretreatment with PD 123319 partially blocked the water and sodium intake, and the MAP induced by ANG II administration (2.3 ± 0.3, 1.1 ± 0.1 ml, and 12 ± 3 mmHg, respectively, N = 9-10). These results suggest the angiotensinergic effect of the MSA on the AT1 and AT2 receptors of the PVN in terms of water and sodium homeostasis and MAP modulation.

On a possible dual role for central noradrenaline in the control of hydromineral fluid intake

Noradrenaline (NOR) is a neurotransmitter presenl in the central nervous system which is related to the control of ingestive behavior of food and fluids. We describe here the relationship between NOR and intake of water and NaCl solution, fluids that are essential for a normal body fluid electrolytic balance. Central NOR has an inhibitory effect on fluid intake, but it either induces or not alterations in food intake. Several ways of inducing water intake, such as water deprivation, meal-associated water intake, administration of angiotensinergic, cholinergic or beta-adrenergic agonists, or administration of hyperosmotic solutions, are inhibited by alpha-adrenergic agonists. Need-induced sodium intake by sodium-depleted animals is also inhibited by alpha-adrenergic agonists. NOR can also facilitate fluid intake. Water intake is elicited by NOR and the integrity of central noradrenergic systems is necessary for a normal expression of water or salt intake in dehydrated animals. The angiotensinergic component of either behavior apparently depends on a central noradrenergic system. NOR probably facililates fluid intake by acting on postsynaptic receptors, but we do not know how it inhibits fluid infake. The inhibitory and facilitatory effects of NOR on ingestive behavior suggest a dual role for this neurotransmitter in the control of hydromineral fluid intake.

Circulation and salt intrusion in the Piaçaguera Channel, Santos (SP)

A análise de dados termohalinos e correntes medidos em uma estação fixa no Canal de Piaçaguera (Estuário de Santos) no inverno foi feita em termos de condições cíclicas da maré (quadratura e sizígia) e quase-estacionária, com o objetivo de caracterizar a estratificação da massa de água estuarina, sua circulação e transporte de sal forçados pela modulação quinzenal da maré. Foram utilizados métodos clássicos de análise de dados observacionais horários e quase sinóticos e de simulações analíticas de perfis estacionários de salinidade e do componente longitudinal da velocidade. Durante o ciclo de maré de quadratura as velocidades de enchente (v<0) e vazante (v>0) variaram de -0.20 m/s a 0.30 m/s, associadas à pequena variação de salinidade entre a superfície e o fundo (26.4 psu a 30.7 psu). No ciclo de sizígia a velocidade aumentou de -0.40 m/s a 0.45 m/s, mas a estratificação de salinidade permaneceu praticamente a mesma. Os perfis estacionários teóricos de salinidade e de velocidade apresentaram boa concordância (Skill próximo a 1,0) quando comparados aos perfis observacionais. Durante a modulação quinzenal da maré não houve alteração na classificação do canal estuarino (tipo 2a-parcialmente misturado e fracamente estratificado), pois a taxa de aumento da energia potencial não foi suficiente para ocasionar a erosão da haloclina. Esses resultados, associados à alta estabilidade vertical (RiL >20) e ao número de Richardson estuarino (1,6), permitem as seguintes conclusões: i) o mecanismo que forçou a circulação e os processos de mistura foi principalmente o balanço da descarga fluvial com a maré, associado ao componente baroclínico da força de gradiente de pressão; ii) não houve variações nas principais características termohalinas e da circulação devido à modulação quinzenal da maré; e iii) os perfis quase estacionários de salinidade e da velocidade foram adequadamente simulados com um modelo analítico clássico.

CIRCULATION AND SALT INTRUSION IN THE PIACAGUERA CHANNEL, SANTOS (SP)

Analysis of thermohaline properties and currents sampled at an anchor station in the Piacaguera Channel (Santos Estuary) in the austral winter was made in terms of tidal (neap and spring tidal cycles) and non-tidal conditions, with the objective to characterize the stratification, circulation and salt transport due to the fortnightly tidal modulation. Classical methods of observational data analysis of hourly and nearly synoptic observations and analytical simulations of nearly steady-state salinity and longitudinal velocity profiles were used. During the neap tidal cycle the flood (v<0) and ebb (v>0) velocities varied in the range of -0.20 m/s to 0.30 m/s associated with a small salinity variation from surface to bottom (26.4 psu to 30.7 psu). In the spring tidal cycle the velocities increased and varied in the range of -0.40 m/s to 0.45 m/s, but the salinity stratification remained almost unaltered. The steady-state salinity and velocity profiles simulated with an analytical model presented good agreement (Skill near 1.0), in comparison with the observational profiles. During the transitional fortnightly tidal modulation period there was no changes in the channel classification (type 2a - partially mixed and weakly stratified), because the potential energy rate was to low to enhance the halocline erosion. These results, associated with the high water column vertical stability (RiL > 20) and the low estuarine Richardson number (RiE = 1.6), lead to the conclusions: i) the driving mechanism for the estuary circulation and mixing was mainly balanced by the fresh water discharge and the tidal forcing associated with the baroclinic component of the gradient pressure force; ii) there was no changes in the thermohaline and circulation characteristics due to the forthnigtly tidal modulation; and iii) the nearly steady-state of the vertical salinity and velocity profiles were well simulated with a theoretical classical analytical model.

Circulation and salt intrusion in the Piaçaguera Channel, Santos (SP)

Analysis of thermohaline properties and currents sampled at an anchor station in the Piaçaguera Channel (Santos Estuary) in the austral winter was made in terms of tidal (neap and spring tidal cycles) and non-tidal conditions, with the objective to characterize the stratification, circulation and salt transport due to the fortnightly tidal modulation. Classical methods of observational data analysis of hourly and nearly synoptic observations and analytical simulations of nearly steady-state salinity and longitudinal velocity profiles were used. During the neap tidal cycle the flood (v<0) and ebb (v>0) velocities varied in the range of -0.20 m/s to 0.30 m/s associated with a small salinity variation from surface to bottom (26.4 psu to 30.7 psu). In the spring tidal cycle the velocities increased and varied in the range of -0.40 m/s to 0.45 m/s, but the salinity stratification remained almost unaltered. The steady-state salinity and velocity profiles simulated with an analytical model presented good agreement (Skill near 1.0), in comparison with the observational profiles. During the transitional fortnightly tidal modulation period there was no changes in the channel classification (type 2a - partially mixed and weakly stratified), because the potential energy rate was to low to enhance the halocline erosion. These results, associated with the high water column vertical stability (RiL >20) and the low estuarine Richardson number (RiE=1.6), lead to the conclusions: i) the driving mechanism for the estuary circulation and mixing was mainly balanced by the fresh water discharge and the tidal forcing associated with the baroclinic component of the gradient pressure force; ii) there was no changes in the thermohaline and circulation characteristics due to the forthnigtly tidal modulation; and iii) the nearly steady-state of the vertical salinity and velocity profiles were well simulated with a theoretical classical analytical model.

Geochemistry and Stable Isotopes of Surface Water and Groundwater in the Continental Pit in Butte, Montana, USA

The Continental porphyry Cu‐Mo mine, located 2 km east of the famous Berkeley Pit lake of Butte, Montana, contains two small lakes that vary in size depending on mining activity. In contrast to the acidic Berkeley Pit lake, the Continental Pit waters have near-neutral pH and relatively low metal concentrations. The main reason is geological: whereas the Berkeley Pit mined highly‐altered granite rich in pyrite with no neutralizing potential, the Continental Pit is mining weakly‐altered granite with lower pyrite concentrations and up to 1‐2% hydrothermal calcite. The purpose of this study was to gather and interpret information that bears on the chemistry of surface water and groundwater in the active Continental Pit. Pre‐existing chemistry data from sampling of the Continental Pit were compiled from the Montana Bureau of Mines and Geology and Montana Department of Environmental Quality records. In addition, in March of 2013, new water samples were collected from the mine’s main dewatering well, the Sarsfield well, and a nearby acidic seep (Pavilion Seep) and analyzed for trace metals and several stable isotopes, including dD and d18O of water, d13C of dissolved inorganic carbon, and d34S of dissolved sulfate. In December 2013, several soil samples were collected from the shore of the frozen pit lake and surrounding area. The soil samples were analyzed using X‐ray diffraction to determine mineral content. Based on Visual Minteq modeling, water in the Continental Pit lake is near equilibrium with a number of carbonate, sulfate, and molybdate minerals, including calcite, dolomite, rhodochrosite (MnCO3), brochantite (CuSO4·3Cu(OH)2), malachite (Cu2CO3(OH)2), hydrozincite (Zn5(CO3)2(OH)6), gypsum, and powellite (CaMoO4). The fact that these minerals are close to equilibrium suggests that they are present on the weathered mine walls and/or in the sediment of the surface water ponds. X‐Ray Diffraction (XRD) analysis of the pond “beach” sample failed to show any discrete metal‐bearing phases. One of the soil samples collected higher in the mine, near an area of active weathering of chalcocite‐rich ore, contained over 50% chalcanthite (CuSO4·5H2O). This water‐soluble copper salt is easily dissolved in water, and is probably a major source of copper to the pond and underlying groundwater system. However, concentrations of copper in the latter are probably controlled by other, less‐soluble minerals, such as brochantite or malachite. Although the acidity of the Pavilion Seep is high (~ 11 meq/L), the flow is much less than the Sarsfield Well at the current time. Thus, the pH, major and minor element chemistry in the Continental Pit lakes are buffered by calcite and other carbonate minerals. For the Continental Pit waters to become acidic, the influx of acidic seepage (e.g., Pavilion Seep) would need to increase substantially over its present volume.

Knowledge of exercise recommendations and energy intake from foods and beverages in relation to exercise behaviors within two Hispanic border communities

This research is a secondary analysis of the Qué Sabrosa Vida population-based cross-sectional study of two predominately Mexican American communities located along the Texas-Mexico border in 2000. There were two aims for this research. The first was to determine the relationship between knowledge of exercise and water recommendations, and exercise behavior and water consumption. The second was to determine the relationship between exercise behavior and percentage of energy consumption from beverages. Chi-square analysis revealed the majority of both populations had adequate knowledge about water and exercise recommendations, although significant percentages of the populations (>40%) did not consume water or exercise in adequate amounts. Knowledge was found to be a component of both behaviors, as it was more prevalent in the adults who exercised and consumed water in adequate amounts. Analysis of variance revealed no significant difference between overall beverage calorie percentage and exercise level (all p-values > 0.05); both regions and genders reported ∼18% of total caloric intake from beverages. There was no disproportionate influence of beverage calories on total caloric intake, after controlling for water consumption and independent of exercise behavior. These findings suggest that overall caloric intake, from both foods and beverages, may be the most influential factor to the energy imbalance contributing to the obesity crisis in these Hispanic border populations. ^

Replacing bare fallow with cover crops in an irrigated cropping system: soil salinity and salt leaching

In irrigated areas where cover crop establishment can be assured, consequent soil or nutrient conservation could increase sustainability of cropping systems. Replacing bare fallow with cover crops may increase sustainability by enhancing soil aggregate stability, water retention capacity or controlling nitrate leaching. Nevertheless, adoption of cover crops increase evapotranspiration and reduce water percolation beyond the root systems; therefore, it could lead to salt accumulation in the upper soil layers. This study was conducted during four years to determine the effect of replacing bare fallow by a cover crop on soil salt accumulation and salt leaching in an irrigated maize production system.

The role of cover crops in irrigated systems: Soil salinity and salt leaching

Soil salinity and salt leaching are a risk for sustainable agricultural production in many irrigated areas. This study was conducted over 3.5 years to determine how replacing the usual winter fallow with a cover crop (CC) affects soil salt accumulation and salt leaching in irrigated systems. Treatments studied during the period between summer crops were: barley (Hordeum vulgare L.), vetch (Vicia villosa L.) and fallow. Soil water content was monitored daily to a depth of 1.3 m and used with the numerical model WAVE to calculate drainage. Electrical conductivity (EC) was measured in soil solutions periodically, and in the soil saturated paste extracts before sowing CC and maize. Salt leaching was calculated multiplying drainage by total dissolved salts in the soil solution, and use to obtain a salt balance. Total salt leaching over the four winter fallow periods was 26 Mg ha−1, whereas less than 18 Mg ha−1 in the presence of a CC. Periods of salt gain occurred more often in the CC than in the fallow. By the end of the experiment, net salt losses occurred in all treatments, owing to occasional periods of heavy rainfall. The CC were more prone than the fallow to reduce soil salt accumulation during the early growth stages of the subsequent cash crop.

(Table 1) Deuterium ratios, chloride content and hydrate volume of pore water and hydrate meltwater from ODP Site 164-996

Site 996 is located above the Blake Diapir where numerous indications of vertical fluid migration and the presence of hydrate existed prior to Ocean Drilling Program (ODP) Leg 164. Direct sampling of hydrates and visual observations of hydrate-filled veins that could be traced 30-40 cm along cores suggest a connection between fluid migration and hydrate formation. The composition of pore water squeezed from sediment cores showed large variations due to melting of hydrate during core recovery and influence of saline water from the evaporitic diapir below. Analysis of water released during hydrate decomposition experiments showed that the recovered hydrates contained significant amounts of pore water. Solutions of the transport equations for deuterium (d2H) and chloride (Cl-) were used to determine maximum (d2H) and minimum (Cl-) in situ concentrations of these species. Minimum in situ concentrations of hydrate were estimated by combining these results with Cl- and d2H values measured on hydrate meltwaters and pore waters obtained by squeezing of sediments, by the means of a method based on analysis of distances in the two-dimensional Cl- d2H space. The computed Cl- and d2H distribution indicates that the minimum hydrate amount solutions are representative of the actual hydrate amount. The highest and mean hydrate concentrations estimates from our model are 31% and 10% of the pore space, respectively. These concentrations agree well with visual core observations, supporting the validity of the model assumptions. The minimum in situ Cl- concentrations were used to constrain the rates of upward fluid migration. Simulation of all available data gave a mean flow rate of 0.35 m/k.y. (range: 0.125-0.5 m/k.y.).