Flow along the Gut and Intestinal Absorption of Salt and Water in Euryhaline Teleosts: A Theoretical Analysis

1974 ◽  
Vol 60 (2) ◽  
pp. 557-566
Author(s):  
K. KRISTENSEN ◽  
E. SKADHAUGE
Keyword(s):  
Water Absorption ◽  
Water Flow ◽  
Permeability Coefficient ◽  
Absorption Rate ◽  
Plasma Osmolality ◽  
European Eel ◽  
Drinking Rate ◽  
Osmotic Permeability ◽  
Nacl Absorption ◽  
Concentration Changes

1. In euryhaline teleosts the transmural salt and water flow and the flow and concentration changes along the gut were simulated by analogue computation. The purpose was to elucidate the interaction of and sensitivity to the parameters of the system particularly with respect to intestinal water absorption. The simulations were based on data obtained from the yellow European eel, the rainbow trout and the cyprinodont Aphanius dispar. 2. When the experimental values for drinking rate, maximal NaCl absorption rate and concentration at half-maximal absorption rate, osmotic permeability coefficient, solute-linked water flow, and concentrations in the gut were used in the model, good consistency was achieved, and predictions could be made. 3. The simulations demonstrated a close linkage between drinking rate and maximal NaCl absorption rate. A large water absorption was only possible close to an optimal drinking rate for each value of maximal NaCl transport rate. The water absorption was little sensitive to the osmotic permeability coefficient of the intestinal wall. 4. As a means of adaptation to waters of high salinity an increase in maximal NaCl absorption rate was shown to be very costly for energetic reasons. This supports indirectly the concept that the osmotic permeability of the gills must go down. The increase in plasma osmolality was a useful part of the adaptation.

Coupling of Transmural Flows of NaCl and Water in the Intestine of the EEl (Anguilla Anguilla)

1974 ◽  
Vol 60 (2) ◽  
pp. 535-546 ◽  
Author(s):  
ERIK SKADHAUGE
Keyword(s):  
Water Flow ◽  
Permeability Coefficient ◽  
Sea Water ◽  
Water Movement ◽  
Anguilla Anguilla ◽  
European Eel ◽  
Surrounding Water ◽  
Pronounced Increase ◽  
Osmotic Permeability ◽  
Local Osmosis

1. An in vivo perfusion of the intestine of the yellow European eel (Anguilla anguilla) was used to measure the net absorption of NaCl and water, the osmotic permeability coefficient, the solute-linked water flow, and the osmolality difference against which the intestine could transport water as functions of the salinity of the surrounding water. The eels were adapted to fresh water, to sea water, and to 1½ strength sea water. 2. The osmolality difference against which the intestine could transport water was observed to be linearly related to the net transmural flow of NaCl; the solute-linked water flow had a constant hypertonicity in spite of differing net flows of NaCl. The findings are in agreement with the hypothesis of uphill water movement being caused by local osmosis due to the salt flow and with a shunt leak proportional to the transmural osmotic difference. 3. An important part of adaptation to waters of higher salinity is a pronounced increase in the intestinal absorption of NaCl. 4. The osmotic permeability coefficient varied from experiment to experiment without relation to the state of adaptation. An explanation for this finding may be that the osmotic permeability of the intestinal epithelium is of little importance for the total intestinal transfer of water.

Moisture Characteristics of Improved Gravelly Guest Soil for Bio-slope-engineering

2021 ◽  
Author(s):  
Junyun Zhang ◽  
Siyuan Chen ◽  
Zhuoling He
Keyword(s):  
Water Absorption ◽  
Field Test ◽  
Permeability Coefficient ◽  
Absorption Rate ◽  
Moisture Capacity ◽  
Water Capacity ◽  
Slope Engineering ◽  
Drought Conditions ◽  
Reasonable Proportion ◽  
Effective Water

Abstract This paper explores the reasonable proportion of guest soil in bio-slope-engineering by means of proportional experiments. In the experiment, rubble and improved materials such as peat and water-retaining agent were selected to study the effect of peat and water-retaining agent content on moisture constant, permeability coefficient and water absorption rate of guest soil.The measurements showed that peat and absorbent agent improve effective water capacity and water absorption speed of guest soil, thus guest soil absorb and hold more effective water; however, with the increase of peat content, wilting moisture capacity of guest soil will increase and its permeability coefficient will also enlarge, which is a disadvantage to plants survival in drought conditions and slope stability in rainy seasons. According to guest soil’s proportional experiments and field test, the favorable amount of rubble, peat, absorbent agent and aggregate agent, is 80%, 20%, 1.0‰ and 1.0‰, respectively, and the reasonable content of fertilizer in guest soil is 100 g/m2. The results may guide the design and construction of Guest soil spraying for bio- slope-engineering.

scholarly journals Preliminary Study of Oil Palm Decanter Cake Natural Polymer Composite (OPDC-NPC)

2014 ◽  
Vol 911 ◽  
pp. 40-44 ◽  
Author(s):  
Muhammad Aqif Adam ◽  
Alawi Sulaiman ◽  
Che Mohd Som Said ◽  
Ayub M. Som ◽  
Azhari Samsu Bahruddin ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Water Absorption ◽  
Polymer Composite ◽  
Palm Oil ◽  
Oil Palm ◽  
Absorption Rate ◽  
Natural Fiber ◽  
Natural Polymer ◽  
Water Absorption Rate ◽  
Decanter Cake

Palm oil industry produces huge amount of oil palm decanter cake (OPDC). Currently it is not yet commercialized however due to its characteristics, it can be used to produce oil palm decanter cake natural polymer composite (OPDC-NPC). NPC is a type of material made by combining natural fiber with polymer. Therefore the objective of this paper is to produce NPC from OPDC and then determine its mechanical and physical properties such as elasticity, stiffness, tensile strength and water absorption rate. The OPDC samples were collected from Felda Trolak Palm Oil Mill. Prior to NPC development, the oil was removed from OPDC using hexane soxhlet extraction method. OPDC-NPC was fabricated using molding method where the mixture of 95% polypropylene (PP) and 5% OPDC were mixed using twin-screw extruder. The results showed that OPDC-NPC has an elasticity of 2231 MPa, stiffness of 30 MPa, tensile strength of 32 MPa and water absorption rate of 0.16 % which was slightly better with the other types of fibers.

Somatostatin-related peptides isolated from the eel gut: effects on ion and water absorption across the intestine of the seawater eel.

1994 ◽  
Vol 188 (1) ◽  
pp. 205-216 ◽  
Author(s):  
T Uesaka ◽  
K Yano ◽  
M Yamasaki ◽  
K Nagashima ◽  
M Ando
Keyword(s):  
Amino Acid ◽  
Water Absorption ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Neuronal Firing ◽  
European Eel ◽  
Amino Acid Residues ◽  
Stimulatory Action ◽  
Adrenergic Antagonist ◽  
Large Peptide

Four somatostatin-related peptides were isolated from eel guts. Two of them were the same as eel SS-25II (eSS-25II) and eel SS-25I (eSS-25I) isolated from European eel pancreas. The remaining two peptides were C-terminal tetradecapeptides (eSS-14II and eSS-14I) of eSS-25II and eSS-25I, respectively. These four peptides all enhanced the serosa-negative transepithelial potential difference and short-circuit current across the seawater eel intestine after pretreatment with isobutylmethylxanthine, serotonin (5-HT) and methacholine, an agonist of acetylcholine (ACh). Among these peptides, eSS-25II was the most potent enhancer, followed by eSS-25I and eSS-14II. Since the large peptide (eSS-25II) acts at a lower concentration than the small somatostatin (eSS-14II), the 11 N-terminal amino acid residues seem to potentiate somatostatin action in the eel intestine. In contrast, eSS-14II was more potent than mammalian SS-14, indicating that the three amino acid residues (Tyr18, Gly21, Pro22) in the C-terminal portion also contribute to the potency of somatostatin. Endogenous somatostatin (eSS-25II) activated net Na+, Cl- and water fluxes across the seawater eel intestine. This stimulatory action was not inhibited by tetrodotoxin or yohimbine, an adrenergic antagonist, indicating that eSS-25II does not act through neuronal firing or through catecholamine release. Thus, eel somatostatins may act directly on the enterocytes, but on a distinct receptor from that for adrenaline, to antagonize the inhibition of NaCl and water absorption by 5-HT and ACh in the seawater eel intestine.

scholarly journals Analysis on the barrier properties of thin film PLA/PBAT reinforced with microcrystalline cellulose

2021 ◽  
Vol 2129 (1) ◽  
pp. 012059
Author(s):  
Sitti Fatimah Mhd Ramle ◽  
Aqilah Abdul Rahim ◽  
Nur Hafizzah Jusoh ◽  
Nurul Fazita Mohammad Rawi ◽  
Che Ku Abdullah Che Ku Alam
Keyword(s):  
Thin Film ◽  
Water Absorption ◽  
Microcrystalline Cellulose ◽  
Absorption Rate ◽  
Barrier Properties ◽  
Poly Lactic Acid ◽  
Plastic Pollution ◽  
Water Absorption Rate ◽  
Environmental Friendly ◽  
Hydrolysis Process

Abstract In recent times, awareness on plastic pollution had increase which brings innovation on new productions to be environmental friendly. Various polymers has been used to analyse the suitability to produce thin films. In this study, Poly lactic acid (PLA) and Polybutylene adipate terephthalate (PBAT) reinforced with microcrystalline cellulose (MCC) were investigated. MCC were produced from selected bamboo for obtaining cellulose, then followed by an acidic hydrolysis process for the processing of microcrystalline cellulose (MCC). In this study, the thin film are focusing on the barrier properties such as water absorption, solvent resistance and absorption test. From the results shows that, the lowest rate of water absorption rate is 1.9% by 1% B-MCC/PLA/PBAT, meanwhile, the highest rate of water absorption is 60.1% by 5% C-MCC/PLA/PBAT. The water absorption rate decrease gradually with the decreasing of amount of MCC in the samples. Lastly, the thin film samples can resist with oleic acid solvents as the condition of thin film samples is still remain but they were not resistance with xylene as the thin film samples were shrinked and degraded. This thin film have a potential to replace the non-biodegradable petrochemical polymer based on their properties such as food contact, availability and cost.

scholarly journals WATER ABSORPTION AND DRYING SHRINKAGE OF RECYCLED FOAMED AGGREGATE CONCRETE

2018 ◽  
Vol 30 (3) ◽  
Author(s):  
Chai Teck Jung ◽  
Tang Hing Kwong ◽  
Koh Heng Boon
Keyword(s):  
Water Absorption ◽  
Absorption Rate ◽  
Drying Shrinkage ◽  
Casting Process ◽  
Concrete Specimen ◽  
Sieve Analysis ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Water Absorption Rate ◽  
Foamed Concrete

Abstract: This paper presents some experimental results and discusses the used of recycled foamed aggregates as natural coarse aggregates replacement in producing concrete. The physical properties of recycled foamed aggregates concrete were investigated. The properties studied are water absorption and drying shrinkage from the concrete early ages until the periods of 56 days. The 100 mm x 100 mm cube specimen was used to study the water absorption at the age of 7, 28 and 56 days. Meanwhile, the 100 mm x 100 mm x 300 mm length prism had been casted and used for drying shrinkage test for recycled foamed aggregates concrete. The foamed aggregates was produced from crushing recycled foamed concrete blocks. It were coated with cement paste to reduce its water absorption ability during casting process. Superplasticizer was used to maintain the workability of fresh concrete with a slump vary between 50 mm to 100 mm. The physical tests were conducted on recycled foamed aggregates to determine their initial properties such as loose bulk density, sieve analysis and water absorption rate. Recycled foamed aggregate concretes were produced with varied water cement ratio. The results obtained indicated that the linear elastic relationship between water cement ratio and water absorption rate. The higher the water cement ratio of concrete specimen will obtained higher water absorption rate. Vice versa, the density is low for drying shrinkage. The water absorption decreased while drying shrinkage becomes more stabilized over curing period.

Annual differences in quality of leaf litter of aspen (Populus tremuloides) affecting rates of decomposition

1988 ◽  
Vol 66 (10) ◽  
pp. 1940-1947 ◽  
Author(s):  
Barry R. Taylor ◽  
Dennis Parkinson
Keyword(s):  
Water Absorption ◽  
Leaf Litter ◽  
Populus Tremuloides ◽  
Decomposition Rate ◽  
Rocky Mountains ◽  
Absorption Rate ◽  
Trembling Aspen ◽  
Leaching Loss ◽  
The Difference

Freshly fallen leaf litter was collected from a stand of trembling aspen (Populus tremuloides Michx.) in the Rocky Mountains of Alberta each autumn from 1981 through 1984. Leaves from 1981 and 1982 were yellow, waxy, and strong. Leaves from 1983 were pale brown and very brittle, and almost 1% of them suffered symmetrical deformities. Leaves from 1984 were composed of 80% yellow leaves and 20% green leaves, which apparently abscissed before senescence. Green and yellow 1984 leaves were distinctly different with respect to total (3 days) leaching loss, leachate conductivity, and proportions of ash, cellulose, and labile material. Green 1984 leaves contained twice as much nitrogen as yellow ones (13.1 vs. 6.5 mg∙g−1) and significantly more phosphorus (1.6 vs. 1.3 mg∙g−1). Leaves of different years varied widely with respect to leaf mass, water absorption rate, mass and conductivity of leachate, and proportions of cellulose, labiles, lignin, and ash, but there was no consistent ordering among years; leaves of different colouration (especially 1981 and 1983) were often physicochemically similar, while leaves identical in appearance were often chemically different. Small but significant differences in N and P concentrations among years were removed by 2 h leaching. Leaves of 1981 decomposing in laboratory microcosms at 26 °C lost less mass than either 1982 or 1983 leaves after 1 month, but not after 2 months. Ability of the cuticle to resist water absorption was probably responsible for the difference in initial decomposition rate.

Osmotic and volaemic effects on drinking rate in elasmobranch fish

2002 ◽  
Vol 205 (8) ◽  
pp. 1115-1122 ◽  
Author(s):  
W. Gary Anderson ◽  
Y. Takei ◽  
N. Hazon
Keyword(s):  
Sea Water ◽  
Plasma Osmolality ◽  
Fold Increase ◽  
Total Blood Volume ◽  
Elevated Plasma ◽  
Total Blood ◽  
Drinking Rate ◽  
Scyliorhinus Canicula ◽  
Drinking Response ◽  
Elasmobranch Fish

SUMMARYAn increase in drinking rate of two species of marine elasmobranch fish, Scyliorhinus canicula and Triakis scyllia, acclimated to 80% sea water was observed following the introduction of 100 % sea water to experimental tanks. The drinking response in both species was found to be maximal within 6 h, and a significant increase was sustained for up to 24 h in T. scyllia. Plasma osmolality was significantly increased within 6 h following introduction of 100 % sea water, and this increase was principally due to elevated plasma Na+ and Cl- concentrations. Administration of 2 mol l-1 mannitol, 75 % sucrose and vehicle(elasmobranch Ringer) did not induce a significant increase or decrease in the drinking rate of S. canicula. However, injection of 20 % NaCl was found to decrease drinking rate significantly in S. canicula 60 min after administration. Controlled haemorrhage of approximately 5.7 % of total blood volume in S. canicula induced a rapid 36-fold increase in drinking over basal levels. The present study demonstrates a physiological dipsogenesis in response to hypovolaemia in marine elasmobranch fish as part of their overall iso/hyperosmoregulatory strategy.

Kinetics of Water and Chloride Exchanges During Adaptation of the European Eel to Sea Water

1973 ◽  
Vol 58 (1) ◽  
pp. 105-121
Author(s):  
R. KIRSCH ◽  
N. MAYER-GOSTAN
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Anguilla Anguilla ◽  
Maximum Level ◽  
Progressive Increase ◽  
Plasma Sodium ◽  
European Eel ◽  
Drinking Rate ◽  
The One ◽  
Kinetics Of

Using isotopic procedures, the drinking rate and chloride exchanges were studied in the eel Anguilla anguilla during transfer from fresh water to sea water. 1. Following transfer to sea water there is a threefold increase of the drinking rate (lasting about 1 h). Then it falls to a minimum after 12-16 h and rises again to a maximum level about the seventh day after the transfer. Then a gradual reduction leads to a steady value which is not significantly different from the one observed in fresh water. 2. The changes with time of the plasma sodium and chloride concentrations are given. Their kinetics are not completely alike. 3. The chloride outflux increases 40-fold on transfer of the eel to sea water, but even so it is very low. After the sixth hour in sea water there is a progressive increase in the flux, so that on the fourth day it is higher (500 µ-equiv. h-1.100 g-1) than in the seawater-adapted animals (230 µ-equiv.h-1.100 g-1). 4. Drinking rate values in adapted animals are discussed in relation to the external medium. The kinetics of the drinking rate together with variations in body weights after freshwater-seawater transfer are discussed in relation to the possible stimulus of the drinking reflex. 5. Chloride fluxes (outflux, net flux, digestive entry) are compared and lead one to assume that in seawater-adapted fish one-third of the chloride influx enters via the gut and two-thirds via the gills.

Cell osmotic water permeability of isolated rabbit proximal straight tubules

1982 ◽  
Vol 242 (4) ◽  
pp. F321-F330 ◽  
Author(s):  
E. Gonzalez ◽  
P. Carpi-Medina ◽  
G. Whittembury
Keyword(s):  
Surface Area ◽  
Water Flow ◽  
Water Permeability ◽  
Permeability Coefficient ◽  
Osmotic Water Permeability ◽  
Water Permeability Coefficient ◽  
Osmotic Water ◽  
Straight Tubules ◽  
Tubular Surface ◽  
Set Up

Proximal straight tubules were dissected and mounted in a chamber with their lumina occluded. The well-stirred bath could be 95% changed within 84 ms to set up osmotic gradients (delta Coi) across the peritubular cell aspect. Volume changes (less than or equal to 10 pl/mm) were estimated from continuous records of diameter changes (error less than 0.1 micrometers). delta Coi greater than or equal to 2-3 mosM could be discerned. delta Coi values from 10 to 44 mosM were used to evaluate Posc, the cell osmotic water permeability coefficient, and extrapolated to delta Coi = 0. Posc = 25.1 (+/- 2.3) X 10(-4) cm3.s-1.osM-1.cm2 tubular surface area-1. These values are lower than those reported for Pose, the transepithelial osmotic water permeability coefficient, and become lower if corrected for the real (infolded) peritubular cell surface area. Thus, for a given osmotic difference, transcellular water flow finds a higher resistance than paracellular water flow. Experiments were also performed with delta Coi greater than 100 mosM, but interpretation of these data is difficult because of the presence of volume regulatory phenomena and other undesirable effects.

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