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This paper will mainly talk about best scheme for the water purification project of the Lake. The engineering used the water diversion metabolism method to purify the water. If the lake area and the water volume are small, the metabolic cycle is relatively short; if the lake area and the water volume are large, the metabolic cycle is relatively long. Simultaneously, the larger the water flow is, the shorter the metabolic cycle period is and the higher the average metabolic rate is. The process of the water metabolism is in agreement with the direction of the water flow movement. With the gradual metabolism of water, different water bodies begin to dilute and diffuse. The engineers will choose the most appropriate water division project according to different water division volumes and water division routes.

The planting of several species adapted to forests areas in the Saharan Atlas would allow one to better fight against the desertification of the vegetation cover of these fragile areas. Thanks to its rapid growth on degraded soils, Robinia pseudoacacia L. has an advantage in the repopulation of these areas undergoing desertification. Operation of this large-scale tree requires good control of germination conditions and growth of plants. The scarification of the seeds of Robinia pseudoacacia L. is necessary to allow the absorption of water by the seeds. Our results show that mechanical scarification with sulphuric acid (75minutes), boiling water (90minutes) and scarification by microwaves (700W) (105seconds) give the best germination rates. The presence of PEG 6000  in the imbibition's solutions reduces considerably the germination rate of the seeds of R. pseudoacacia L. A 70 % decrease in the optimal rate of germination is observed when the osmotic pressure of the imbibition solution is at -4.65 bar., (Copyright © 2017 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.)

Aquaporins are transmembrane proteins, ubiquitous in the human body. Inserted into the cell membranes, they play an important role in filtration, absorption and secretion of fluids. However, the excellent compromise between selectivity and permeability of aquaporins remains elusive. In this review, we focus on the hourglass shape of aquaporins, and we investigate its influence on water permeability, using numerical calculations and a simple theoretical model. We show that there is an optimum opening angle that maximizes the hydrodynamic permeability, and whose value is close to the angles observed in aquaporins., (© 2015 médecine/sciences – Inserm.)

Corneal neovascularization is defined as the presence of vessels within the normally avascular corneal stroma. This physiopathological process is the consequence of local hyper-expression of pro-angiogenic factors in response to tissue damage. These new vessels (neovessels), initially immature and poorly developed, predispose the cornea to lipid exudation, inflammation, and scarring. Additionally, the influx of vascular cells into the stroma induces a loss of the cornea's immune privilege, resulting in a higher rate of graft rejection. In this literature review, we touch on epidemiological, physiopathological, and clinical aspects of corneal neovascularization, as well as secondary complications., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

The combined daily consumption of fresh water ranges from 200 to 700 liters per capita per day in most developed countries, with about 70% being used for agricultural needs. Unlike other resources such as the different forms of energy, water has no other alternatives. With the looming prospect of global water crisis, the recent laudable success in deciphering the early steps in the signal transduction of the "stress hormone" abscisic acid (ABA) has ignited hopes that crops can be engineered with the capacity to maintain productivity while requiring less water input. Although ABA was first discovered in plants, it has resurfaced in the human brain (and many other non-plant organisms : sea sponge, some parasites, hydra to name a few), suggesting that its existence may be widespread. In humans, more amazingly, ABA has shown anti-inflammatory and antiviral properties. Even its receptors and key signaling intermediates have homologs in the human genome suggesting that evolution has re-fashioned these same proteins into new functional contexts. Thus, learning about the molecular mechanisms of ABA in action using the more flexible plant model will be likely beneficial to other organisms, and especially in human diseases, which is topical in the medical circle. ABA can accumulate up to 10 to 30-fold in plants under drought stress relative to unstressed conditions. The built up of the hormone then triggers diverse adaptive pathways permitting plants to withstand temporary bouts of water shortage. One favorite experimental model to unravel ABA signaling mechanisms in all of its intimate detail is based on the hormone's ability to elicit stomatal closure - a rapid cellular response of land plants to limit water loss through transpiration. Each microscopic stoma, or pore, is contoured by two specialized kidney-shaped cells called the guard cells. Because land plants are protected by a waxy cuticle impermeable to gas exchange, the stomatal pores are thus the primary portals for photosynthetic CO(2) uptake. Drought, by biasing pathways that lead to rapid closure of these pores, has therefore a negative impact on photosynthesis, and consequently, biomass as well. The stomatal aperture widens and narrows by expansion and contraction, respectively, of these flanking guard cells caused by changes in the intracellular concentrations of ion fluxes. These transport mechanisms most likely share fundamental principles with any excitable cell. These events require coordination of channels, vacuolar and membrane transporters that generate a specific pattern of electrical signals that relay the ABA stimulus. Research on ABA begun in the 1960's has now been crowned by the achievement of having identified the soluble ABA receptor that turns on and off the activities of a kinase/phosphatase pair, as the heart of the signaling complex. Results distilled from the latest structural studies on these ABA receptors, characterized by the so-called START domain, are beginning to tender the most exciting promise for rational design of agonists and antagonists towards modulating stress adaptive ability in plants. This review will chart the recent extraordinary progress that has enlightened us on how ABA controls membrane transport mechanisms that evoke the fast stomatal closing pathway., (© Société de Biologie, 2013.)

Plants are sessile organisms that have developed the capacity to detect slight variations of their environment. They are able to perceive these environmental signals and to transduce them by signaling pathways in order to trigger adaptative responses. Lipid signaling elements play a central role in these pathways in plants. A key element is phosphatidic acid (PA), which can be produced by two pathways. In the first one, phospholipids are hydrolysed by phospholipase D (PLD) to release PA. In the second one, PA is produced through the activity of phospholipase C (PLC) to produce diacylglycerol (DAG) which is then phosphorylated by DAG kinase (DAGK). The amount of PA in the cell is regulated by PA kinase, which phosphorylates PA to produce diacylglycerolpyrophosphate (DGPP), considered as a second messenger as well. PLCs play a dual role in cell signaling by regulating the amount of intracellular Ca(2+), another essential second messenger. Phosphoinositides, such as PI3P, PI4P and PI(4,5)P(2), are substrates of PLCs and PLDs and are considered as second messengers also. In this review, we present recent data regarding the specific features of these lipid signaling pathways in plant compared with other eukaryotes., (© Société de Biologie, 2010.)

Apelin is a recently identified peptide which plays an important role in cardiovascular function and in water metabolism. Apelin and its receptor APJ (apelin system) are involved in zebra fish and xenopus cardiovascular development. Apelin is a pro-angiogenic factor. Apelin is a potent cardiac inotropic agent and exerts a vasodilatory effect in arterial and venous territories. Apelin decreases vasopressin production and its plasma level is conversely related to plasma vasopressin. Several effects of the apelin system counteract those of the renin angiotensin system. It may represent a new and promising therapeutic opportunity for the treatment of cardiovascular diseases.

The understanding of water traffic through biological membranes has tremendously progressed with the discovery of the aquaporins. Aquaporins water channels inserted in lipid bilayer drive specific, regulated, water flux under osmotic gradient. Some of them, the aquaglycéroporines, are permeated by urea, glycerol and other small solutes in addition to water. More than 450 aquaporins have been described, and 13 in vertebrates. Aquaporins 1-4, 6-8 and 11 are expressed in kidney, all along the nephron except the thick ascending limb of Henle. Each of them has a specific localization and regulation, and contributes to the body water balance.

In the present study, the effect of temperature and water activity on fungal growth and ochratoxin production on coffee-based medium was assessed. Optimal growth of three Aspergillus strains was observed in the same ecological conditions, namely 30 degrees C and 0.99 water activity. Maximal daily growth is 11.2, 6.92, and 7.22 mm/day for Aspergillus niger, Aspergillus carbonarius, and Aspergillus ochraceus, respectively. However, ecological conditions for optimal ochratoxin production vary according to the toxinogenic strain, with water activity as a limiting factor. Such an ochratoxin A production is inhibited at 42 degrees C and 0.75 water activity. Correspondence between laboratory tested water activity and that measured on a sun-dried ripe cherry batch shows that the first 5 days of drying are critical for fungal growth and ochratoxin A production. Accordingly, artificial drying of cherries at temperatures above 42 degrees C will impede not only fungal growth but also contamination with ochratoxin A.

Arterial hypertension is a complex trait influenced by a variety of environmental and genetic factors. Several approaches can be used to identify its susceptibility genes : one is to study rare monogenic forms of hypertension, like familial hyperkalemic hypertension (FHH). Also known as pseudohypoaldosteronism type 2 or Gordon syndrome, FHH is characterized by hypertension, hyperkalemia despite normal renal glomerular filtration rate, abnormalities which are particularly sensitive to thiazide diuretics. Mild hyperchloremia, metabolic acidosis, and suppressed plasma renin activity are associated findings. Despite its phenotypic and genetic heterogeneity, mutations in two related genes, WNK1 and WNK4, were recently identified. These genes belong to a newly identified family of serine-threonine (with no lysine [K]) kinases. Both are highly expressed in the kidney and in a variety of epithelia involved in chloride transport. It has thus been postulated that these two kinases could be implicated in a new pathway of ionic transport regulation. Several studies have very recently confirmed this hypothesis in vitro, in Xenopus oocytes or kidney cell lines. They have shown that, in the renal distal tubule, WNK4 inhibits sodium reabsorption and potassium secretion, via inhibition of NCC (thiazide-sensitive Na+-Cl- cotransporter) and K+ channel ROMK activity, respectively. Interestingly, FHH mutations have opposite effects : while they lead to loss of NCC inhibition, they increase ROMK inhibition. Moreover, they also increase paracellular permeability to chloride of MDCK cells. WNK4 also inhibits apical and basal chloride transporters present in extra-renal epithelia, such as CFEX and Na+-K+-2 Cl-, respectively. It is also interesting to note that the WNK4-mediated negative regulation of NCC activity is in turn inhibited by WNK1. By its role on several transporters, WNK4 appears as a putative key regulator of ionic transport and blood pressure.

Seven varieties of bred wheat and seven varieties of durum wheat were cultivated in three different sites from the area of Errachidia (southeastern Morocco). These sites differ by the degree of salinity in the irrigation water. Results obtained showed that the reduction in leaf area is the principal strategy that makes it possible to attenuate the effects of the reduction in the availability of water under saline stress. Bread wheat, which limited the reduction in the leaf area, with the risk to undergo some hydrous problems, seems to better preserve its photosynthetic potentialities and grain productivity.

Plasma sodium concentration, or natremia, results from three main factors: exchangeable sodium (Na+), exchangeable potassium (K+) and total body water (H2O). Its alterations often imply a change in cell volume. Understanding dysnatremias is essential for the treatment and prevention of hydromineral disorders. Extra-cellular fluid tonomoles consist almost exclusively of Na+ salts. Their dilution is the tonicity. K+ is an essential tonomole for intra-cellular fluid tonicity. The balance between intra and extracellular tonicities depends on water movements and is responsible for changes in intra- and extracellular fluid volumes. Cell volume is therefore depending on the tonicity balance. A change in body tonicity (which is not osmolality) can be correctly and rapidly appreciated by measuring the (Na+ + K+) and H2O balances. Clinical cases emphasize the misleadings resulting from the free-water clearance calculation or the only measurements of urinary losses. They also demonstrate that tonicity balance provides indications for therapy whereas analyses based upon electrolyte-free water do not. Intakes should be quantified with the same care than losses. The units used must be coherent to allow a quick and easy understanding at the bedside. Tonicity balance should be taught and Na+ + K+ and H2O balances should be routinely utilized by practitioners, dieticians and nurses in the concerned pediatrics, in particular intensive care, internal medicine, nephrology, pediatry and anesthesiology.

Dilution rate and volume of water in the rumen varied between rations and dairy cows but were independent of the feed intake level. Correlations between rates of transit of liquid and particles were poor.

In hemodialysis, an excessive oversimplification leads to confuse the transfer direction of a given solute (patient towards dialysate or dialysate towards patient) and the direction of transmembranar concentration gradient. Applied to sodium, this confusion leads to the usual iso- or hypotonic dialysate use, in order to eliminate the patient's sodium overload. We show here how the use of a high sodium dialysate allows the elimination of the sodium overload and makes the free water clearance (approached by the Na-free water clearance) positive, which is the necessary condition to restore an hydro-electrolytic equilibrium near from the normal. That allows a disappearance of hypovolemic symptoms during hemodialysis, a better general condition and a possible increase of water intake between sessions.

A water loading test was performed in 10 patients with a cancer of the digestive tract without hyponatremia and in 10 controls. A lowering of the CfH2O was observed in the patients during the test, as well as an increase in the cortisol plasmatic rates, while aldosterone rates remained normal. To valid the hypothesis of a hypervasopressinic state in these patients, 15 cancerous patients and 12 controls had a plasmatic ADH dosage, which pointed indicated higher hormonal level in the first group.

The authors discuss the various recent discoveries and fundamental data on absorption from the digestive tube and the digestive hormones. The practical applications of these data in oral feeding are underlined.

Isolated hepatocytes incubated at 1 degrees C loss K, gain Na and water. Rewarming results in a transient increase in K and Na permeabilities. These are insensitive to quinine, suggesting that they are not caused by an intracellular Ca accumulation.

One or two weeks after total mechanical occlusion of the dog colon, the organ is severely dilated, but the intraluminal pressure never exceeds 8 cm of water, and there are no obvious histological lesions of the mucosa. Perfusion of the occluded colon in vivo reveals marked inhibition of ion and water absorption; however, except in the case of potassium, net secretion as occurs in the occluded ileum does not develop. Glucose absorption in vivo and active phenylalanine and beta-methyl-D-glucoside transport in vitro are reduced in the mucosa of the occluded colon.

Eighteen healthy male subjects, were investigated under normal sodium intake and after 5 days of high and low sodium intake. Under normal sodium intake, the following mean values were observed -- plasma osmolality (Posm): 294 +/- 5 mOsm/kg -- plasma volume (Vp): 33.9 +/- 4,3 ml/kg -- urinary sodium output (UNa.V): 173 +/- 73 mEq/24 h -- urinary antidiuretic hormone (A.D.H.): 68.8 +/- 35.6 ng/24 h. Under low sodium intake these values decreased to -- Posm: 289 +/- 4 m Osm/kg -- Vp: 32.7 +/- 3.2 ml/kg -- UNa.V: 12 +/- 9 mEq/24 h -- A.D.H.: 40.9 +/- 16.3 ng/24 h. Under high sodium intake these values increased to -- Posm: 298 +/- 5 m Osm/kg -- Vp: 36.3 +/- 4.1 ml/kg -- UNa.V: 325 +/- 67 mEq/24 h -- A.D.H.: 118.2 +/- 45.5 NG/24 H. Highly significant correlations are found between Posm and A.D.H. and between the Posm or A.D.H. and UNa.V. Interest is focused on UNa.V since the correlation between A.D.H. and UNa.V (r = 0.78) is more significant than that between A.D.H. and Posm (r = 0.47). Overriding of Posm on Vp in the regulation of A.D.H. secretion is again demonstrated. Plasma renin activity decrease when A.D.H. increase.

In certain epithelial tissues, water permeability is markedly increased by antidiuretic hormone. This so-called hydrosmotic effect has been shown to be mediated by 3'-5' cyclic adenosine monophosphate, which, in turn, alters the permeability o the luminal membrane of receptor cells. This review deals wity ultrastructural alterations occurring in the membrane, as observed with freeze-fracture electron microscopy. Basically, these alterations consist of organized particle aggregates which appear in the apical membrane. In all experimental conditions, similar aggregates can be observed in the membrane of cytoplasmic vesicles. ADH stimulation triggers the fusion of these vesicles with the apical membrane resulting in the concomitant transfer of particle aggregates. It has been shown, in a wide range of experimental conditions, that both number and total area of the aggregates are directly proportional to the water permeability of the tissue. It is generally assumed that particle aggregates contain transmembrane channels that are selectively to water.

Photosynthetic oxygen evolution results from the dehydrogenation of water molecules by the chlorophyll-center cation of photosystem II. The primary charge separation occurs between the chlorophyll center and the primary acceptor. The positive charges are then transferred to the manganese cluster able to accumulate four positive equivalents. Protons are liberated during this process. The oxygen evolution requires the presence of Ca2+ and Cl-. The oxidation of two water molecules, and the transfer of the electrons to the plastoquinone pool, are done by a supra-molecular complex which utilizes photons as substrate, and can therefore transfer electrons against a large redox potential difference.

Tritiated water 3H, injected by intraperitoneal route into 7-week old male Rats, was incorporated into lipids synthesized de novo. The Rats were killed 0, 3, 7, 10, 15, 30, 60 and 120 min. after tracer injection. The results show that an optimal interval of about 10 min. between tracer injection and animal sacrifice was necessary to obtain a correct estimate of lipogenesis de novo by avoiding intertissue exchanges.

Eggs in Leucophaea maderae are present in an ootheca which remains in the broodsac until hatching of the larvae. During incubation, the water content of the eggs increases from 36 to 77%, the dry weight remaining constant. Water is possibly provided by the mother.

In a group of 10 patients with a cancer of the digestive tract, some investigations, performed before the surgical intervention, showed the evidence of an adrenal-postpituitary imbalance in favour of the second term. During a water loading, the plasmatic cortisol rates stayed more higher by cancerous subjects than by controls (but not the plasmatic aldosterone rates); nevertheless, the vasopressin secretion rates could be considered as more higher yet in cancerous subjects because the free water clearances were significantly lowered by these patients. Such results have to be put in relation with the opposite effects of vasopressin and corticoids on the cell mitosis, as well as with some therapeutical attempts that end to check this type of endocrine imbalance.

1.--In Sphaeroma serratum, the diffusion fluxes of water are 3 or 4 times more important in sea water (SW) than in diluted (50%) sea water. In 100% and in 50% SW influx equals the outflux. 2.--When the animal is quickly transferred from 100% SW to 50% SW, and from 50% SW to 100% SW, the outflux is instantaneously and entirely reset. 3.--The main factor of the instantaneous resettlement of the outflux seems to be the variation of the concentration of Na+ or Cl- or both together in the external medium; the Ca2+ and Mg2+ concentrations do not seem to have any effect on the diffusion flux. 4.--The validity of our results is discussed (theory of unstirred layers, blood-circulation, oxygen interchange, ultrastructure). Our results are compared with those obtained in other Crustaceans and in Fishes.

In the first part of this review, the morphological characteristics of the interfaces between blood and some compartments of the central nervous system have been described. The blood-brain barrier (BBB) is situated between the blood and the brain extracellular space (ECS) at the endothelial cells of brain capillaries joined by tight junctions. The blood-cerebrospinal fluid (CSF) barrier is mainly situated at the epithelium of the choroid plexuses. In this second part, the general mechanisms and methods of study of the transport of low molecular weight substances across the BBB are reviewed. In addition water and solute transports across the interfaces are described. The third part will deal with the transport of metabolic substrates and of drugs, with the barrier to neurotransmitters and with the physiological alterations of the permeability of the blood-brain barrier. Blood-brain transport is transcellular. According to the nature of the transported molecule it can be either by diffusion through the membranes (lipophilic molecules) or carrier-mediated (hydrophilic molecules such as metabolic substrates). In vivo methods of study have first been experimental. The recent use of short-lived positron-emitting radioisotopes should extent their use to clinical studies. In vitro measurement of transport on isolated capillaries or choroid plexuses give additional information. Water exchange between plasma and the brain is rapid. However, the permeability of the brain capillaries for water is lower than that of other capillaries and of most membranes, but more similar to that of lipid bilayers and of most tight epithelia. The permeability for water of the choroid plexuses which secrete CSF is much higher than that of brain capillaries. CSF and ECS electrolyte composition is under strict homeostatic regulation, leaving it independent of fluctuations in plasma composition. This constant composition is the consequence of the low permeability of brain capillaries to electrolytes as well as that of the presence of a sodium potassium dependent ATPase on the abluminal membrane of capillaries and the apical membrane of choroid plexuses. This enzyme contributes to the extrusion of potassium from the CSF and ECS and allows a large gradient of potassium to be created between ECS and plasma. A low level of potassium in CSF and ECS is in fact needed for normal nerve conduction.