Sodium Absorption Research Articles

Activation of the intestinal tissue renin-angiotensin system by transient sodium loading in salt-sensitive rats.

Background:The renal tissue renin-angiotensin system is known to be activated by salt loading in salt-sensitive rats; however, the response in other organs remains unclear.Method:Spontaneously hypertensive rats were subjected to normal tap water or transient high-salt-concentration water from 6 to 14 weeks of age and were thereafter given normal tap water. From 18 to 20 weeks of age, rats given water with a high salt concentration were treated with an angiotensin II type 1 receptor blocker, valsartan.Results:Sustained blood pressure elevation by transient salt loading coincided with a persistent decrease in the fecal sodium content and sustained excess of the circulating volume in spontaneously hypertensive rats. Administration of valsartan sustainably reduced the blood pressure and normalized the fecal sodium levels. Notably, transient salt loading persistently induced the intestinal tissue renin-angiotensin system and enhanced sodium transporter expression exclusively in the small intestine of salt-sensitive rats, suggesting the potential connection of intestinal sodium absorption to salt sensitivity.Conclusion:These results reveal the previously unappreciated contribution of the intestinal tissue renin-angiotensin system to sodium homeostasis and blood pressure regulation in the pathophysiology of salt-sensitive hypertension.

Environmental Assessment of Groundwater Quality for Irrigation Purposes: A Case Study Of Hillah City In Iraq

This study was conducted to evaluate the groundwater quality of wells located around the Hillah city of Iraq, for the purposes of determining its suitability as water for agricultural irrigation, according to the Irrigation Water Quality Index (IWQI). The number of wells that are being investigated was 24. The spatial distribution of water quality parameters was investigated using ArcGIS software. Ten parameters were established for the dry and wet seasons of 2018 and 2019, which include pH, electric conductivity (EC), total dissolved solids (TDS), calcium, potassium, magnesium, bicarbonate, sodium, chloride and sulfuric. The results showed that all pH and sodium absorption ratio values were within the allowable limits. About 69%, and 75% electric conductivity, total dissolved solids, values respectively were higher than the allowable limits. Most values of positive and negative ions were higher than the allowable limits. In 2018, the water quality of (4%) of wells number was classified as moderate restriction and approximately 96% was poor quality in dry season, while the IWQI was enhanced in the wet season. In 2019, the quality of water was dropped as most of the water quality was classified as severe restriction and few in the high restriction for the dry season. These values were increased in the wet season due to the freshwater dilution effect. Water quality index show that a large percentage of the wells have poor water quality leads to severe restriction for irrigation requirements and need relatively high permeability soils and salt-resistant plants.

Physicochemical properties of groundwater in parts of Irun Akoko, Ondo State, Nigeria

Ten groundwater samples from hand dug wells were collected at Irun Akoko within the basement complex of part of southwestern Nigeria. The aim of the study was to determine the groundwater suitability for both drinking and irrigation purposes. The groundwater samples were analysed for some physical and chemical constituents including pH, Total Dissolved Solids (TDS), turbidity, Na, Ca, Mg, K, Cl, SO4, PO4 and NO3. The pH (7.0 – 7.9) and TDS (12.26 – 19.35 mg/l) of the groundwater indicate that the water is neutral to slightly alkaline and fresh respectively. The order of relative abundance for concentration of cations in the groundwater is K>Ca>Na>Mg, while that of anions is Cl>SO4>NO3>PO4. The concentrations of potassium in about 90% and chloride in about 40 % of the samples were above the World Health Organization (WHO) standard for drinking water. Other hydro-geochemical parameters Ca, Mg, Na, SO4, PO4 and NO3 falls within the WHO standards. Values of Sodium Absorption Ratio (SAR) classified the water as excellent for irrigation purposes. The Soluble Sodium Percentage (SSP) values classified eighty percent of the water to be of good quality and the remaining samples as fair for irrigation purposes. However, using the Magnesium Adsorption Ratio (55.0 – 68.9 %) the samples may have hazardous effects on the soil. Generally, groundwater in the study area is suitable for both domestic and irrigation uses.

Toxic wastewater status for irrigation usage at Gazipur and Savar industrial vicinity of Bangladesh

Treated wastewater can promote to minimizing the water stress in agricultural field due to the scarcity of irrigation water. The aim of the experiment was to determine the toxic metallic contamination for wastewater irrigation in the investigated area. Analytical techniques were used to determine quality parameter and ionic constituents. Samples were considerably alkaline (pH = 7.55 to 10.05). As for recommended TDS, samples were categorizing as freshwater (60%) and brackish water (40%). Electrical Conductivity (EC) and Sodium Absorption Ratio (SAR) express the salinity and alkalinity indicates the classes C4S1, C3S1 & C2S1. Soluble sodium percentage (SSP) categorized in different grade in samples. Regarding Hardness (HT), samples were rank as very hard, hard, and moderately hard. Upon analysis, all HCO3 was extremely hazardous, noxious for watering to plants and 56% samples of Cl, 92% of Cu and all sample of Cd were exceeded the limit thus risky for irrigation usage but zinc and iron have no effect on irrigation. Finally, the results revealed that all samples except few under test were unsuitable for irrigation due to having toxic metals such as Cu, Mn, Cd, HCO3, and Cl. From the above discussion, we concluded that most of the parameters like Cu, Mn, Cd, HCO3, and Cl were exceeded the maximum acceptable level and wastewater must be treated to remove all toxic elements before irrigation into the field. Moreover, this wastewater is a great value to reducing the water stress in farm level due to limited irrigation water.

Biocrust islands enhance infiltration, and reduce runoff and sediment yield on a heavily salinized dryland soil

Salinity and sodicity are major forms of land degradation in drylands worldwide, reducing soil function, and threatening pastoral livelihoods. Dryland soils are often dominated by biocrusts, surface aggregations of lichens, bryophytes, fungi and other minute organisms that stabilize surface soils. Biocrusts could have a role in maintaining hydrological functions in heavily salinized areas, but there have been few studies, and the mechanisms are poorly understood. We tested whether biocrust mosses and lichens enhanced infiltration, and reduced runoff and sediment yield, on biocrusted islands scattered among extensive patches of bare highly saline soils in northeaster Iran. Biocrusted soils had greater cumulative infiltration and hydraulic conductivity, less runoff, which commenced later, and lower sediment yields than bare soils. The water content of biocrusted soils was greater than bare soils, but only at low matric potentials. Biocrusted surfaces were alkaline, more sandy, had lower levels of sodium, chloride, and calcium-plus-magnesium ions, and a lower sodium absorption ratio than bare soils. Structural equation modelling showed that increasing salinity was associated with a suppression of the negative effect of biocrusts on runoff. Potential mechanisms for reduced runoff likely relate to enhanced soil aggregation and porosity of biocrusted soils leading to greater retention of soil water content at low matric potentials, as well as an ability of mosses and lichens to capture and store surface water or to permit infiltration into the uppermost surface layers. Overall, our findings reveal a strong association between moss- and lichen-dominant biocrusts and soil hydrological processes, and suggest that these crusts play an important role in maintaining hydrological function in heavily salinized soils.

Classification of groundwater suitability for irrigation purposes using a comprehensive approach based on the AHP and GIS techniques in North Kurdufan Province, Sudan

Deterioration of groundwater quality due to drastic human interventions is rising at an alarming rate particularly in lower- and middle-income countries. Yet, limited research effort has been devoted to monitoring and ascertaining groundwater quality. The present study develops a comprehensive irrigation water quality index (IWQI) for rating water quality of shallow and deep aquifers in North Kurdufan province, Sudan. The new approach is developed to overcome the deficiencies of the existing irrigation indices and coming up with a unified decision for classifying water quality for irrigation purposes. Because of these indices like permeability index (PI), sodium absorption ratio (SAR), etc., depending on specific elements, entirely subjective, as well as the great variations in their results, particularly when classifying water quality. Thus, IWQI is created based on eight indices that are generally used to evaluate irrigation water quality, plus three physicochemical parameters have been proven an impact on water quality. The analytic hierarchy process (AHP) is applied to minimize the subjectivity at assign parameter weights under multiple criteria decision analysis tools (MCDA). The spatial distribution of IWQI agrees with the spatial distribution of the most parameters. The results of our approach reveal that the majority of samples are suitable for irrigation uses for both aquifers except few wells in the confined aquifer. Also, noted that there are very variations in the irrigation indices results for classifying water quality. The comparison result showed that the new index robust, fair calculations and has best classifying of water quality.

Evaluation of the quality of irrigation water using the Agriwater software

Since water is an increasingly limited resource, having methods for evaluating its quality is necessary to ensure an adequate and sustainableuse for human consumption, agriculture and industry. The aim of this work was to describe agriwater software for evaluating the quality of irrigation water. The software consisted of the following stages: a) development of a database capable of hosting all the information stored in the software; b) conversion of chemical units; c) indexes calculation; and d) evaluation of performance and efficiency in data processing. The Agriwater software converts measuring units of ions to mg L-1, meq L-1 and mmol L-1, calculating the following water quality indexes: sodium absorption ratio, effective salinity, potential salinity and chloride toxicity. The result is Agriwater software, a professional tool that can handle, analyze and evaluate thousands of data in seconds in an intuitive and simple way.

Self-Standing Film Assembled using SnS-Sn/Multiwalled Carbon Nanotubes Encapsulated Carbon Fibers: A Potential Large-Scale Production Material for Ultra-stable Sodium-Ion Battery Anodes.

High-energy sodium-ion batteries have a significant prospective application as a next-generation energy storage technology. However, this technology is severely hindered by the lack of large-scale production of battery materials. Herein, a self-standing film, assembled with SnS-Sn/multiwalled carbon nanotubes encapsulated in carbon fibers (SnS-Sn/MCNTs@CFs), is prepared using ball milling and electrospinning techniques and used as sodium-ion battery anodes. To compensate the poor internal conductivity of SnS-Sn nanoparticles, MCNTs are used to interweave SnS-Sn nanoparticles to improve the conductivity. Moreover, the designed three-dimensional carbon fiber conductive network can effectively shorten the diffusion path of electron/Na+, accelerate the reaction kinetics, and provide abundant active sites for sodium absorption. Benefiting from these unique features, the self-standing film offers a high reversible capacity of 568 mA h g-1 at 0.1 A g-1 and excellent cycling stability at 1 A g-1 with a reversible capacity of 359.3 mA h g-1 after 1000 cycles. In the sodium-ion full cell device, the capacity is stable at 283.7 mA h g-1 after 100 cycles at a current of 100 mA g-1. This work provides a new strategy for electrode design and facilitates the large-scale application of the sodium-ion battery.

Prediction of water quality parameters using machine learning models: a case study of the Karun River, Iran.

Accurate water quality predicting has an essential role in improving water management and pollution control. The machine learning models have been successfully implemented for modelling total dissolved solids (TDS), sodium absorption ratio (SAR) and total hardness (TH) content in aquatic ecosystems with insufficient data. However, due to multiple pollution sources and complex behaviours of pollutants, these models' effect in predicting TDS, SAR, and TH levels in the Karun River system is still unclear. Given this problem, multiple linear regression (MLR), M5P model tree, support vector regression (SVR) and random forest regression (RFR) models were used to predict TDS, SAR and TH variables in the four stations in the Karun River for 1999-2019 period. Initially, to reduce the number of input variables, the principal component analysis (PCA) technique was used. The developed models are valued in terms of the coefficient of determination (R2) and the root mean square error (RMSE). Base on the PCA, it was found that sodium (Na), chloride (Cl) and TH and Na and Cl are the most influential inputs on TDS and SAR, respectively, while calcium (Ca) and magnesium (Mg) are the most effective on TH. The results indicated that RFR, SVR and MLR models had the lowest error in predicting TDS, SAR and TH, respectively, in all stations. RFR model had the highest performance for predicting TDS (R2= 0.98, RMSE= 70.50 mg l-1), SVR model for predicting SAR (R2= 0.99, RMSE= 0.04) and MLR model for predicting TH (R2= 0.99, RMSE= 1.54 mg l-1) in Darkhovin station. The comparison of the results indicated that the machine learning models could satisfactorily estimate the TDS, SAR and TH for all stations.

Suitability Assessment of Groundwater for Irrigation in Some Villages of Sirsa District, Haryana (India)

To determine the groundwater quality a total of twenty groundwater samples were collected from some villages of Sirsa district, Haryana, India, which is one of the most important agricultural areas of the state. The groundwater samples were collected in November 2016 from different villages of the city Sirsa. The suitability of groundwater for irrigation was assessed by determining the Sodium Absorption Ratio, % Na, Kelly’s Index, Permeability index, EC, Chloro-alkaline indices and Residual Sodium Carbonate. The CAI analysis shows the reverse cation exchange for most of the stations. The Gibbs diagrams show the precipitation dominance for most of the stations. The Piper diagram shows the alkali dominance for most of the samples. On the basis of the values of different parameters the quality of ground water at different stations was categorized into three different classes mainly excellent, good or unsuitable.

Depressive hypertension: A proposed human endotype of brain/gut microbiome dysbiosis

Hypertension (HTN) is frequently linked with depression (DEP) in adults with cardiovascular disease (CVD), yet the underlying mechanism and successful management remain elusive. We approached this knowledge gap through the lens that humans are eukaryote-prokaryote "meta-organisms," such that cardiovascular disease dysregulation is a mosaic disorder involving dysbiosis of the gut. We hypothesized that patients diagnosed with hypertension plus depression harbor a unique gut microbial ecology with attending functional genomics engaged with their hosts' gut/brain axis physiology. Stool microbiome DNA was analyzed by whole metagenome shotgun sequencing in 54 subjects parsed into cohorts diagnosed with HTN only (N = 18), DEP only (N = 7), DEP plus HTN (DEP-HTN) (N = 8), or reference subjects with neither HTN nor DEP (N = 21). A novel battery of machine-learning multivariate analyses of de-noised data yielded effect sizes and permutational covariance-based dissimilarities that significantly differentiated the cohorts (false discovery rate (FDR)-adjusted P ≤ .05); data clustering within 95% confidence interval). Metagenomic significant differences extricated the four cohorts. Data of the cohort exhibiting DEP-HTN were germane to the interplay of central control of blood pressure concomitant with the neuropathology of depressive disorders. DEP-HTN gut bacterial community ecology was defined by co-occurrence of Eubacterium siraeum, Alistipes obesi, Holdemania filiformis, and Lachnospiraceae bacterium 1.1.57FAA with Streptococcus salivariu. The corresponding microbial functional genomics of DEP-HTN engaged pathways degrading GABA and beneficial short chain fatty acids (SCFA), and are associated with enhanced sodium absorption and inflammasome induction. These data suggest a new putative endotype of hypertension, which we denote "depressive-hypertension" (DEP-HTN), for which we posit a model that is distinctive from either HTN alone or DEP alone. An "endotype" is a subtype of a heterogeneous pathophysiological mechanism. The DEP-HTN model incorporates a unique signature of microbial taxa and functional genomics with crosstalk that putatively intertwines host pathophysiology involving the gastrointestinal tract with disruptions in central control of blood pressure and mood. The DEP-HTN endotype model engages cardiology with gastroenterology and psychiatry, providing a proof-of-concept foundation to explore future treatments, diagnosis, and prevention of HTN-coupled mood disorders.

SARS‐CoV‐2 May Hijack GPCR Signaling Pathways to Compromise Lung Ion and Fluid Transport

The tropism of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), a virus responsible for the ongoing coronavirus disease 2019 (COVID‐19) pandemic, towards the host cells is determined, at least in part, by the expression and distribution of its cell surface receptor, angiotensin‐converting enzyme 2 (ACE2). The virus further exploits the host cellular machinery to gain access into the cells; its spike protein is cleaved by a host cell surface transmembrane serine protease 2 (TMPRSS2) shortly after binding ACE2 followed by its proteolytic activation at a furin cleavage site. The virus primarily targets the epithelium of the respiratory tract which is covered by a tightly regulated airway surface liquid (ASL) layer that serves as a primary defense mechanism against respiratory pathogens. The volume and viscosity of this fluid layer is regulated and maintained by a coordinated function of different transport pathways in the respiratory epithelium. We argue that SARS‐CoV‐2 may potentially alter evolutionary conserved second‐messenger signaling cascades via activation of G‐protein coupled receptors (GPCRs) or by directly modulating G protein signaling. Such signaling may in turn adversely modulate transepithelial transport processes, especially those involving cystic fibrosis transmembrane conductance regulator (CFTR) and epithelial Na+ channel (ENaC), thereby shifting the delicate balance between anion secretion and sodium absorption that controls homeostasis of this fluid layer. As a result, activation of the secretory pathways including CFTR‐mediated Cl‐ transport may overwhelm the absorptive pathways such as ENaC‐dependent Na+ uptake and initiate a pathophysiological cascade leading to lung edema, one of the most serious and potentially deadly clinical manifestations of COVID‐19.

Effect of phosphogypsum on saline-alkalinity and aggregate stability of bauxite residue

A column experiment was conducted to investigate the effect of phosphogypsum (PG) on the saline- alkalinity, and aggregate stability of bauxite residue. Results showed that: with increasing leaching time, the concentrations of saline-alkali ions decreased while the concentration increased in bauxite residue leachate; compared with CK (control group) treatment, pH, electric conductivity (EC), exchangeable sodium percentage (ESP), sodium absorption ratio (SAR), and exchangeable Na+ content of bauxite residue were reduced following PG treatment; average particle sizes in aggregates following CK and PG treatments were determined to be 155 and 193 nm, respectively. SR-μCT test results also confirmed that bauxite residue following PG treatment acquired larger aggregates and larger pore diameter. These results indicate that the PG treatment could significantly modulate the saline-alkalinity, and simultaneously enhance aggregate stability of bauxite residue, which provides a facile approach to reclaim bauxite residue disposal areas.

Evaluation of Groundwater Quality in Virudhunagar Taluk, Tamil Nadu, India by using Statistical Methods and GIS Technique

Abstract In the present study, twenty water samples were collected during pre-monsoon (June 2017) and post-monsoon (December 2017) seasons. The water samples were analyzed to determine various chemical parameters like chloride, fluoride, sulphate, nitrate, phosphate. During pre-monsoon (PRM) and post-monsoon (POM) the order of dominance of anion in the water samples are HCO3-> TDS > Cl-> SO42-> TH > NO3-> F-> PO4- and TDS >HCO3->SO42->Cl-> TH >NO3->F->PO4-, respectively. The order of dominance of cations are Na+> Ca2+> Mg2+> K+ in both the seasons. The irrigation water quality was determined using the parameters such as sodium absorption ratio (SAR), Kelly’s ratio (KR), residual sodium carbonate (RSC), potential salinity (PS), permeability index (PI), sodium percentage (SP), magnesium hazard, calcium to magnesium molar ratio. The groundwater’s geochemical control and hydrogeochemistry were evaluated using the Piper, Chadha, scatter and Gibbs plots. This study reveals that groundwater quality is unfit for drinking purposes at a few places in the study area.

Improving salinity tolerance in Salvia officinalis L. by foliar application of salicylic acid

BackgroundHigher absorption and translocation of sodium (Na) and chlorine (Cl) ions in plant tissue can lead to serious physiological and biochemical changes. However, salicylic acid (SA) is a natural signaling molecule responsible for the induction of environmental stress tolerance in plants. Spraying SA could provide protection against several types of stress such as salinity. This study aimed to show the influence of SA spraying (0.5 and 1 mM) on the damaging effects of NaCl toxicity (150 mM) in Salvia officinalis L. plants.ResultsThe results showed that salinity strongly inhibited the growth of aerial and root parts and this inhibition was accompanied by a significant decrease in the production of chlorophyll pigments (by 63%). There was also a significant accumulation of Na, mainly in the roots. This accumulation of Na+ ions was accompanied by a decrease of calcium (Ca), potassium (K) and phosphorus (P) concentrations. However, SA mainly at 0.5 mM, greatly improved plant growth, essential oils and chlorophyll pigments synthesis. Besides, SA led to a decrease in Na content and an improvement in Ca, K and P content in the leaves and roots. Salt stress decreased the essential oil yield from 1.2% (control) to 0.4% (NaCl). Furthermore, gas chromatography–mass spectrometry analysis of essential oils exhibited that the 1,8-cineol, α-thujone, and camphor were identified as the main components of essential oils under all treatments. However, we noted in stressed plant treated or not with SA the appearance of the new majority compound thujanone. Salt stress decreased the major compounds content. SA spray under stress condition increased the content of major compounds compared to stressed plants untreated with SA. The histological study in scanning electron microscopy showed the peltate glands density decreased strongly under NaCl toxicity. However, SA application on stressed plants increased peltate glands density. On the other hand, the glands of stressed plants often show certain anomalies in the morphology: the first anomaly observed was the presence of glandular structures characterized by deformations in the form of small protuberances located on the head of the gland. The second, a less common abnormality is the morphological change in certain glands that change from a spherical to an ovoid shape. On another hand, all these anomalies were not detected in stressed plants sprayed with SA. Therefore, the absence of these anomalies under the effect of SA showed the repairing effect of this growth regulator.ConclusionThe findings of the present work suggest that spraying of SA may be useful for improving the plant growth in NaCl-contaminated areas.

Effects of earthworm casts on water and salt movement in typical Loess Plateau soils under brackish water irrigation

Soil salinization severely degrades agricultural land and significantly impacts agricultural productivity. Earthworm casts, as a pollution-free improver, can effectively enhance the structure and properties of soil; however, their effects on water and salt movement in soil, under brackish water irrigation, remain unclear. In this study, we conducted laboratory experiments to investigate the effects of earthworm cast treatments under four application rates (untreated, 1%, 3%, and 5% of soil weight) on water and salt movement in anthrosols (CS) and cambisols (AS) from the Loess Plateau. The application of earthworm casts was found to inhibit soil infiltration and evaporation, except for the 1% treatment in CS; inhibition also increased with more concentrated treatments. Compared to that in untreated soil, the infiltration rate and cumulative evaporation in cast-treated CS decreased by 23.9–32.2% and 5.1–9.8%, whereas in AS, they decreased by 17.6–28.5% and 8.6–20.7%. The application of earthworm casts significantly reduced the electrical conductivity of the upper 20 cm of soil, and the reduction increased with more concentrated treatments. Compared with untreated soil, the application of earthworm casts significantly reduced the sodium absorption ratio in the upper 0–20 cm by 15.6–31.1% in CS and 12.2–28.1% in AS. Applying earthworm casts significantly reduced the exchangeable sodium percentage of soil at 0–20 cm by 16.5–25.9% in CS and 13.5–22.5% in AS. Therefore, the application of earthworm casts effectively alleviated soil salinity and sodicity in both soil types by reducing the salt content in the upper 0–20 cm under brackish water irrigation.

Effect of alkalis on products of enforced carbonation of cement paste

An approach based on enforced, wet carbonation of cement fines obtained from recycled concrete and its application as an SCM in new composite cements is presented as a new carbon capture and utilization technology. While the carbonation products are stable at a wide range of conditions, it is found that alkalis have a strong impact on product properties, as shown by carbonation in NaOH solutions in this study. Calcium carbonate precipitates mainly as calcite, regardless of the alkali concentration, however, the alkalis influence the size of the calcite crystals, which are smaller at low alkali concentrations. Alkalis modify also the structure of the alumina-silica gel, as a result of absorption of either sodium or calcium ions in this phase. Furthermore, alkali ions present in the solution influence directly the sulphate content of the carbonated cement paste, since a higher alkali concentration in the solution promotes leaching of sulphate.

Effect of Sprinkler and Basin Irrigation Systems on Yield and Water Use Efficiency of Canola Crop

An experiment was conducted to assess the yield potential and Water Use Efficiency (WUE) of Canola crop grown under sprinkler and basin irrigation techniques on a clay loam soil. The experiment was designed by the Principles of Randomized Complete Block Design (RCBD) with two treatments, viz. T1 (sprinkler irrigation method) and T2 (basin irrigation method), replicated four times. Marginal quality water with Electrical Conductivity (ECw) of 1.83 dS/m and pH of 8.2 was used for irrigation. The crop yield obtained under T1 and T2 treatments were 1,407.9 and 1,123.8 kg ha-1, respectively; 20% more yield was observed under T1 treatment. In the given order of treatments (T1 and T2), the Canola crop used 3,605 and 4,453 m3 ha-1 of irrigation water, hence, 19% water saving was achieved by T1 treatment. The WUE attained under T1 and T2 treatments were 0.39 and 0.25 kg m-3 respectively; therefore, 35.8% WUE was enhanced under T1 treatment. While comparing the agronomic parameters of the crop under the two procedures, all the observed parameters (plant height, number of branches plant-1, number of pods plant-1, pod length, number of seeds pod-1 and biomass plant-1) were superior in case of T1 treatment than T2 treatment. The soil Electrical Conductivity (ECse), Sodium Absorption Ratio (SAR), and Exchangeable Sodium Percentage (ESP) increased, and pH decreased under both the treatments, however, the maximum increase in ECse, SAR and ESP, and maximum decrease in pH occurred under T2 treatment. Statistical analysis showed that the crop yield, irrigation water use, WUE, ECse, pH, SAR, ESP, and all the agronomic parameters differed significantly (p < 0.05) under the two treatments.

The role of NHE3 (Slc9a3) in oxalate and sodium transport by mouse intestine and regulation by cAMP.

Intestinal oxalate transport involves Cl−/HCO3 − exchangers but how this transport is regulated is not currently known. NHE3 (Slc9a3), an apical Na+/H+ exchanger, is an established target for regulation of electroneutral NaCl absorption working in concert with Cl−/HCO3 − exchangers. To test whether NHE3 could be involved in regulation of intestinal oxalate transport and renal oxalate handling we compared urinary oxalate excretion rates and intestinal transepithelial fluxes of 14C‐oxalate and 22Na+ between NHE3 KO and wild‐type (WT) mice. NHE3 KO kidneys had lower creatinine clearance suggesting reduced GFR, but urinary oxalate excretion rates (µmol/24 h) were similar compared to the WT but doubled when expressed as a ratio of creatinine. Intestinal transepithelial fluxes of 14C‐oxalate and 22Na+ were measured in the distal ileum, cecum, and distal colon. The absence of NHE3 did not affect basal net transport rates of oxalate or sodium across any intestinal section examined. Stimulation of intracellular cAMP with forskolin (FSK) and 3‐isobutyl‐1‐methylxanthine (IBMX) led to an increase in net oxalate secretion in the WT distal ileum and cecum and inhibition of sodium absorption in the cecum and distal colon. In NHE3 KO cecum, cAMP stimulation of oxalate secretion was impaired suggesting the possibility of a role for NHE3 in this process. Although, there is little evidence for a role of NHE3 in basal intestinal oxalate fluxes, NHE3 may be important for cAMP stimulation of oxalate in the cecum and for renal handling of oxalate.

ABSORÇÃO DE MACRONUTRIENTES E SÓDIO PELO TOMATEIRO SUBMETIDO A IRRIGAÇÃO COM E SEM DÉFICIT HÍDRICO, UTILIZANDO DIFERENTES CONCENTRAÇÕES DE ÁGUA RESIDUÁRIA

ABSORÇÃO DE MACRONUTRIENTES E SÓDIO PELO TOMATEIRO SUBMETIDO A IRRIGAÇÃO COM E SEM DÉFICIT HÍDRICO, UTILIZANDO DIFERENTES CONCENTRAÇÕES DE ÁGUA RESIDUÁRIA FRANCIELLY GUIEIRO GOMES DE SOUSA2; RENATA DA SILVA CUBA DE CARVALHO3; MARA RÚBIA MENDES DE MELO4 E HÉLIO GRASSI FILHO5 1 Trabalho originado da dissertação de mestrado do primeiro autor intitulada: “Irrigação com água residuária em diferentes diluições e disponibilidade para a cultura do tomate cereja” 2 Doutoranda, Departamento de Engenharia Rural, Faculdade de Ciências Agronômicas – FCA – Unesp, Câmpus Botucatu, Avenida Universitária, 3780, CEP 18610-034, Altos do Paraíso, Botucatu-SP, Brasil, fran.engagricola@gmail.com 3 Doutora, Departamento de Engenharia Rural, Faculdade de Ciências Agronômicas – FCA – Unesp, Câmpus Botucatu, Avenida Universitária, 3780, CEP 18610-034, Altos do Paraíso, Botucatu-SP, Brasil, renatacuba@hotmail.com 4 Doutoranda, Departamento de Produção e Melhoramento Vegetal. Faculdade de Ciências Agronômicas (FCA/UNESP – Campus de Botucatu). Rua José Barbosa de Barros, 1780. CEP: 18.610-307, Botucatu-SP - Brasil. mara_mendesmelo@hotmail.com 5 Professor Titular do Departamento de Solos e Recursos Ambientais da Faculdade de Ciências Agronômicas - FCA/UNESP, Campus Botucatu (SP), heliograssi@fca.unesp.br 1 RESUMO Perante a grande demanda de água no planeta para o desenvolvimento de atividades econômicas e consumo doméstico, estudos relacionados ao aproveitamento da água residuária no meio agrícola podem ajudar a minimizar problemas de escassez desse recurso. Sendo assim o objetivo do presente trabalho foi avaliar a absorção de macronutrientes e sódio pela cultura do tomate irrigado com e sem déficit hídrico, utilizando água residuária. O experimento foi conduzido em ambiente protegido, o sistema de irrigação foi por gotejamento, e o manejo da irrigação foi baseado na evaporação do tanque classe ‘A’ instalado dentro do ambiente. Foram determinadas duas lâminas: 70 e 100% da evapotranspiração da cultura, nas quais foram utilizadas água de abastecimento e de esgoto doméstico tratado em quatro diluições: 25, 50, 75 e 100%. Assim, foi possível avaliar a absorção de macronutrientes e sódio, na área foliar e frutos, através de análise química. Os resultados obtidos, indicaram que as plantas irrigadas com déficit hídrico absorveram maior quantidade dos nutrientes N, K, Mg e S. No entanto quanto maior a porcentagem de água residuária na irrigação, maior foi a absorção de sódio pelas plantas e frutos. Palavras chave: nutrição, reúso doméstico, manejo da irrigação, Lycopersicon esculentum L. SOUSA, F. G. G.; CARVALHO, R. S. C.; MELO, M. R. M.; GRASSI FILHO, H. ABSORPTION OF MACRONUTRIENTS AND SODIUM BY TOMATOES SUBMITTED TO NORMAL AND WATER DEFICIENT IRRIGATION SCHEMES USING VARIOUS CONCENTRATIONS OF WASTEWATER 2 ABSTRACT The high worldwide demand for water use in economic development and domestic consumption has led to studies on the agricultural use of wastewater that can help minimize the problem of scarcity of this resource. This study aimed to evaluate the absorption of macronutrients and sodium from cultivated tomatoes, irrigated with wastewater, under normal and water deficient irrigation schemes. The experiment was conducted in a greenhouse, we used a drip irrigation system that was managed on the basis of evaporation from a Class A tank placed in the experimental area. Two irrigation depths were determined: 70 and 100% of the crop evapotranspiration, supply water, and four dilutions of domestic wastewater were used: 25, 50, 75, and 100%. We evaluated the absorption of macronutrients and sodium via chemical analysis of the leaves and fruits. Results showed that plants irrigated using the water deficit irrigation scheme absorbed more N, K, Mg, and S nutrients. However, the higher the percentage of wastewater used for irrigation, the higher the absorption of sodium by plants and fruits. Keywords: nutrition, domestic reuse, irrigation management, Lycopersicon esculentum L.