946 resultados para Effect of water


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The extraction and use of metals has been the mainstay for the sustained development and progress of a nation. Metals, though fairly stable in the natural environment are found in trace quantities in water bodies. Attention has therefore been focused to identify the metals that impair the water quality. In the last few decades the concern about the fate of these metals in the aquatic system has been gaining momentum, particularly in the industrial belts. The disasters caused by metal poisoning in recent times have prompted an indepth study of the interaction of metals with aquatic biota. Kerala, basically an agriculture oriented state has witnessed the upsurgence of various industries as a part of the nationwide economic development programme. Cochin has been identified as the industrial capital of the state.The present study is an attempt towards a better understanding of the metal-phytoplankton interactions with special reference to the physiological changes in the species. various parameters such as temperature, salinity, pH, nutrients, number of cells, photosynthetic pigments, carbohydrates, protein and lipid are studied to highlight the complexity of metal..phytoplankton interaction

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The impact of two crop planting methods and of the application of cyanobacterial inoculants on plant growth, yield, water productivity and economics of rice cultivation was evaluated with the help of a split plot designed experiment during the rainy season of 2011 in New Delhi, India. Conventional transplanting and system of rice intensification (SRI) were tested as two different planting methods and seven treatments that considered cyanobacterial inoculants and compost were applied with three repetitions each. Results revealed no significant differences in plant performance and crop yield between both planting methods. However, the application of biofilm based BGA bio-fertiliser + 2/3 N had an overall positive impact on both, plant performance (plant height, number of tillers) and crop yield (number and weight of panicles) as well as on grain and straw yield. Higher net return and a higher benefit-cost ratio were observed in rice fields under SRI planting method, whereas the application of BGA + PGPR + 2/3 N resulted in highest values. Total water productivity and irrigation water productivity was significantly higher under SRI practices (5.95 and 3.67 kg ha^(-1) mm^(-1)) compared to practices of conventional transplanting (3.36 and 2.44), meaning that using SRI method, water saving of about 34 % could be achieved and significantly less water was required to produce one kg of rice. This study could show that a combination of plant growth promoting rhizobacteria (PGPR) in conjunction with BGA and 2/3 dose of mineral N fertiliser can support crop growth performance, crop yields and reduces overall production cost, wherefore this practices should be used in the integrated nutrient management of rice fields in India.

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Understanding links between the El Nino-Southern Oscillation (ENSO) and snow would be useful for seasonal forecasting, but also for understanding natural variability and interpreting climate change predictions. Here, a 545-year run of the general circulation model HadCM3, with prescribed external forcings and fixed greenhouse gas concentrations, is used to explore the impact of ENSO on snow water equivalent (SWE) anomalies. In North America, positive ENSO events reduce the mean SWE and skew the distribution towards lower values, and vice versa during negative ENSO events. This is associated with a dipole SWE anomaly structure, with anomalies of opposite sign centered in western Canada and the central United States. In Eurasia, warm episodes lead to a more positively skewed distribution and the mean SWE is raised. Again, the opposite effect is seen during cold episodes. In Eurasia the largest anomalies are concentrated in the Himalayas. These correlations with February SWE distribution are seen to exist from the previous June-July-August (JJA) ENSO index onwards, and are weakly detected in 50-year subsections of the control run, but only a shifted North American response can be detected in the anaylsis of 40 years of ERA40 reanalysis data. The ENSO signal in SWE from the long run could still contribute to regional predictions although it would be a weak indicator only

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The effects of diet and breed on the concentration of water-soluble flavour precursors, namely sugars, free amino acids, ribonucleotides, creatinine, carnosine and creatine, were studied in beef longissimus hanborum muscle. Diet had a significant effect on the concentration of free amino acids, with animals fed on grass silage having higher free amino acid levels than animals fed on a concentrate diet, whereas animals fed concentrates had a higher total reducing sugar content. Differences between a beef breed (Aberdeen Angus x Holstein-Friesian) and a dairy breed (Holstein-Friesian) were generally small. (C) 2007 Elsevier Ltd. All rights reserved.

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Changes in glycolytic metabolites, nucleotide degradation products, free amino acids and other amino compounds were monitored in beef muscle (M. longissimus lumborum), stored for 21 days at 4 degrees C, in order to evaluate how post-mortem conditioning may affect flavour formation in beef. The major effects observed in sugar-related substances were the dephosphorylation of the phosphates of glucose, fructose and mannose, to yield their free sugars, as well as the breakdown of inosine 5'-monophosphate, to give a sixfold increase in ribose. Total reducing sugars increased by only 15% during conditioning, while glycogen levels remained unchanged from 2 days post-slaughter. Free amino acids increased during conditioning, particularly between days 7 and 14. Phenylalanine, methionine, lysine, leucine and isoleucine were the amino acids showing the greatest increase with conditioning time, with methionine, in particular, showing a sevenfold increase during the conditioning period. The effects of these precursor changes on cooked beef flavour are discussed. (c) 2007 Elsevier Ltd. All rights reserved.

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Fecal water (FW) has been shown to exert, in cultured cells, cytotoxic and genotoxic effects that have implications for colorectal cancer (CRC) risk. We have investigated a further biological activity of FW, namely, the ability to affect gap junctions in CACO2 cell monolayers as an index of mucosal barrier function, which is known to be disrupted in cancer. FW samples fi-om healthy, free-living, European subjects that were divided into two broad age groups, adult (40 +/- 9.7 yr; n = 53) and elderly (76 +/- 7.5 yr; n = 55) were tested for effects on gap junction using the transepithelial resistance (TER) assay. Overall, treatment of CACO2 cells with FW samples fi-om adults increased TER (+ 4 %), whereas FW from elderly subjects decreased TER (-5%); the difference between the two groups was significant (P < 0.05). We also measured several components of FW potentially associated with modulation of TER, namely, short-chain fatty acid (SCFA) and ammonia. SCFAs (propionic, acetic, and n-butyric) were significantly lower in the elderly population (-30%, -35%, and -21%, respectively, all P pound 0.01). We consider that FW modulation of in vitro epithelial barrier function is a potentially useful noninvasive biomarker, but it requires further validation to establish its relationship to CRC risk.

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Antioxidant properties in food are dependent on various parameters. These include the pH value and interactions with food components, including proteins or metal ions. food components affect antioxidant stability and also influence the properties of microorganisms and their viability. This paper describes an investigation of the effect of pH on the antioxidant and antibacterial properties of caffeic acid in different media. The pH values studied, using an oil-in-water emulsion as model system, were 3, 5 (with and without phosphate buffer), and 9. Effects of mixtures of caffeic acid, bovine serum albumin (BSA), and Fe (III) on oxidative deterioration in the emulsion samples were studied. The results show that the antioxidant activity of caffeic acid was increased by the presence of BSA. This effect was pH dependent and was affected by the presence of iron Ions. Antibacterial properties were also pH dependent. The minimum concentration of caffeic acid required to inhibit some microorganisms in the pH range of 5 to 7 was determined. A concentration of 0.41% (w/w) caffeic acid was enough to inhibit the growth of some of the studied microorganisms in the pH range of 5 to 7. However, near-neutral pH concentrations higher than 0.4% were needed to inhibit some microorganisms, including Listeria monocytogenes, E. coli, and Staphylococcus aureus, in the medium.

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Fermented dairy products and their component bacteria have been shown to possess health-promoting functions in consumers and recently have been suggested to reduce the risk of colorectal cancer. Kefir and ayran are two popular fermented milk drinks that have their origins in the Caucasus region of Russia. The present study aimed to evaluate their potential anticancer properties in colon cells in vitro. The comet assay and transepithelial resistance assay were used to assess the effect of kefir and ayran supernatants on genotoxicity of fecal water samples and on intestinal tight junction integrity. Their antioxidant capacity was measured by trolox equivalent antioxidant capacity assay and compared with that of unfermented milk. The results showed that DNA damage induced by 2 of 4 fecal water samples was significantly decreased by kefir and ayran supernatants and with ayran the effect was dose-dependent. However no effect on intestinal tight junctions was observed. The supernatants of kefir and ayran contained high amounts of acetic and lactic acid but only a very small quantity of caproic and butyric acid, and they showed significantly greater antioxidant capacity than milk. These findings suggest kefir and ayran can reduce DNA damage, which might be due to their antioxidant capacities.

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Reaction of Cu(ClO(4))(2)center dot 6H(2)O with the 1:2 condensate of benzildihydrazone and 2-acetylpyridine, in methanol in equimolar ratio yields a green compound which upon recrystallisation from 1:1 CH(2)Cl(2)-C(6)H(6) mixture affords [CuL(H(2)O)](ClO(4))(2)center dot 1/2C(6)H(6). The complex crystallises in the space group P-1 with a = 8.028(11) angstrom, b = 12.316(17) angstrom, c = 18.14(3) angstrom, alpha = 97.191(10)degrees, beta = 94.657(10)degrees and gamma = 108.039(10)degrees. It is single helical with the metal having a distorted trigonal bipyramidal N(4)O coordination sphere. The acid dissociation constant of the Cu(I) complex in CH(3)CN is 3.34 +/- 0.19. The X band EPR spectrum of the compound is rhombic with g(1) = 2.43, g(2) = 2.10 g(3) = 2.02 and A(1) = 79.3 x 10(-4) cm(-1). The Cu(II/I) potential of the complex in CH(2)Cl(2) at a glassy carbon electrode is 0.43 V vs SCE. It is argued that the copper-water bond persists in the corresponding copper(I) species. Its implications on the single helix-double helix interconversion in copper helicates are discussed. DFT calculations at the B3LYP/6-311G** level shows that the binding energy of water in the single helicol live-coordinate copper(I) species [CuL(H(2)O)](+) is similar to 40 kJ mol(-1).

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A drag law accounting for Ekman rotation adjacent to a flat, horizontal bou ndary is proposed for use in a plume model that is written in terms of the depth-mean velocity. The drag l aw contains a variable turning angle between the mean velocity and the drag imposed by the turbulent bound ary layer. The effect of the variable turning angle in the drag law is studied for a plume of ice shelf wat er (ISW) ascending and turning beneath an Antarctic ice shelf with draft decreasing away from the groundi ng line. As the ISW plume ascends the sloping ice shelf–ocean boundary, it can melt the ice shelf, wh ich alters the buoyancy forcing driving the plume motion. Under these conditions, the typical turning ang le is of order 10° over most of the plume area for a range of drag coefficients (the minus sign arises for th e Southern Hemisphere). The rotation of the drag with respect to the mean velocity is found to be signifi cant if the drag coefficient exceeds 0.003; in this case the plume body propagates farther along and across the b ase of the ice shelf than a plume with the standard quadratic drag law with no turning angle.

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Recent laboratory measurements show that absorption by the water vapour continuum in near-infrared windows may be about an order of magnitude higher than assumed in many radiation codes. The radiative impact of the continuum at visible and near-infrared wavelengths is examined for the present day and for a possible future warmer climate (with a global-mean total column water increase of 33%). The calculations use a continuum model frequently used in climate models (‘CKD’) and a continuum model where absorption is enhanced at wavelengths greater than 1 µm based on recent measurements (‘CAVIAR’). The continuum predominantly changes the partitioning between solar radiation absorbed by the surface and the atmosphere; changes in top-of-atmosphere net irradiances are smaller. The global-mean clear-sky atmospheric absorption is enhanced by 1.5 W m−2 (about 2%) and 2.8 W m−2 (about 3.5%) for CKD and CAVIAR respectively, relative to a hypothetical no-continuum case, with all-sky enhancements about 80% of these values. The continuum is, in relative terms, more important for radiation budget changes between the present day and a possible future climate. Relative to the no-continuum case, the increase in global-mean clear-sky absorption is 8% higher using CKD and almost 20% higher using CAVIAR; all-sky enhancements are about half these values. The effect of the continuum is estimated for the solar component of the water vapour feedback, the reduction in downward surface irradiance and precipitation change in a warmer world. For CKD and CAVIAR respectively, and relative to the no-continuum case, the solar component of the water vapour feedback is enhanced by about 4 and 9%, the change in clear-sky downward surface irradiance is 7 and 18% more negative, and the global-mean precipitation response decreases by 1 and 4%. There is a continued need for improved continuum measurements, especially at atmospheric temperatures and at wavelengths below 2 µm.

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Groundnuts cultivated in the semiarid tropics are often exposed to water stress (mid-season and end season) and high temperature (> 34 °C) during the critical stages of flowering and pod development. This study evaluated the effects of both water stress and high temperature under field conditions at ICRISAT, India. Treatments included two irrigations (full irrigation, 100 % of crop evapotranspiration; and water stress, 40 % of crop evapotranspiration), four temperature treatments from a combination of two sowing dates and heat tunnels with mean temperatures from sowing to maturity of 26.3° (T1), 27.3° (T2), 29.0° (T3) and 29.7 °C (T4) and two genotypes TMV2 and ICGS 11. The heat tunnels were capable of raising the day temperature by > 10 °C compared to ambient. During the 20-day high-temperature treatment at flowering, mean temperatures were 33.8° (T1), 41.6° (T2), 38.7° (T3) and 43.5°C (T4). The effects of water stress and high temperature were additive and temporary for both vegetative and pod yield, and disappeared as soon as high-temperature stress was removed. Water use efficiency was significantly affected by the main effects of temperature and cultivar and not by water stress treatments. Genotypic differences for tolerance to high temperature can be attributed to differences in flowering pattern, flower number, peg-set and harvest index. It can be inferred from this study that genotypes that are tolerant to water stress are also tolerant to high temperature under field conditions. In addition, genotypes with an ability to establish greater biomass and with a significantly greater partitioning of biomass to pod yield would be suitable for sustaining higher yields in semiarid tropics with high temperature and water stress.

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Proteins contain hydrophilic groups, which can bind to water molecules through hydrogen bridges, resulting in water vapour adsorption. An increase in the degree of cross-linking can be a method to improve the cohesiveness force and functional properties of protein-based films. Thus, the objective of this work was to evaluate the effect of chemical treatment of gelatin with formaldehyde and glyoxal on the mechanical properties, water vapour permeability (WVP) and water vapour sorption characteristics of gelatin-based films. Films were produced using gelatin, with and without chemical treatment. The formaldehyde treatments caused a significant increase in the tensile strength and a reduction in the WVP of films. The Guggenheim-Anderson-De Boer and Halsey models could be used to model the sorption isotherms of films. It was observed that an increase in temperature produced a decrease in water sorption, and the chemical modifications did not affect the monolayer moisture content. Copyright (c) 2007 John Wiley & Sons, Ltd.

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In this paper, calcium molybdate (CaMoO(4)) crystals (meso- and nanoscale) were synthesized by the coprecipitation method using different solvent volume ratios (water/ethylene glycol). Subsequently, the obtained suspensions were processed in microwave-assisted hydrothermal/solvothermal systems at 140 degrees C for 1 h. These meso- and nanocrystals processed were characterized by X-ray diffraction (X R I)), Fourier transform Raman (FT-Raman), Fourier transform infrared (FT-IR). ultraviolet visible (UV-vis) absorption spectroscopies, held-emission gun scanning electron microscopy (FEG-SEM). transmission electron microscopy (TEM). and photoluminescence (PL) measurements. X RI) patterns and FT-Raman spectra showed that these meso- and nanocrystals have a scheelite-type tetragonal structure without the presence of deleterious phases. FT-IR spectra exhibited a large absorption band situated at around 827 cm(-1), which is associated with the Mo-O anti-symmetric stretching vibrations into the [MoO(4)] clusters. FEG-SEM micrographs indicated that the ethylene glycol concentration in the aqueous solution plays an important role in the morphological evolution of CaMoO(4) crystals. High-resolution TEM micrographs demonstrated that the mesocrystals consist of several aggregated nanoparticles with electron diffraction patterns of monocrystal. In addition, the differences observed in the selected area electron diffraction patterns of CaMoO(4) crystals proved the coexistence of both nano- and mesostructures, First-principles quantum mechanical calculations based on the density functional theory at the B3LYP level were employed in order to understand the band structure find density of states For the CaMoO(4). UV-vis absorption measurements evidenced a variation in optical band gap values (from 3.42 to 3.72 cV) for the distinct morphologies. The blue and green PI. emissions observed in these crystals were ascribed to the intermediary energy levels arising from the distortions on the [MoO(4)] clusters clue to intrinsic defects in the lattice of anisotropic/isotropic crystals.