Water Balance and Urine Production in the Australian Arid-Zone Crab Holthuisana Transversa

1980 ◽  
Vol 87 (1) ◽  
pp. 237-246
Author(s):  
PETER GREENAWAY
Keyword(s):  
Body Weight ◽  
Water Balance ◽  
Arid Zone ◽  
Tritiated Water ◽  
Water Flux ◽  
Water Output ◽  
Osmotic Water ◽  
Urine Production ◽  
Site Water ◽  
Freshwater Decapods

The permeability to tritiated water (hourly exchange fraction = 0·164) and the rate of urine flow (0·47% body weight/day) are lower than recorded in other freshwater decapods. The calculated net osmotic water flux (2·71% body weight/day) is 5 times the water output in the urine, indicating that there is extrarenal excretion of water. Water balance is maintained in the absence of urine production, again indicating an extrarenal excretory site. Water turnover is greater for crabs in burrows than for crabs kept in air of 98% R.H., indicating relatively favourable conditions of moisture availability at the base of the burrow.

scholarly journals Design of Land Application Systems for Water Reuse

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2120
Author(s):  
Clifford B. Fedler
Keyword(s):  
Water Balance ◽  
Water Reuse ◽  
Water Storage ◽  
Land Application ◽  
Design Approach ◽  
Capital Costs ◽  
Application Systems ◽  
Nutrient Salt ◽  
Site Water ◽  
Irrigated Crops

Water reuse via land application is old technology; but the water balance only design approach and practice has not worked well. There are many benefits of water reuse by irrigating crops; however, there are some risks if not designed properly. When the design approach uses a combined water-nutrient-salt balance, the most effective and sustainable, long-term system is achieved. This approach provides a design based on land area requirements, on-site water storage, and economic return from the irrigated crops. The single, most often overlooked step in the water balance is accounting for the water stored in the soil. When spread over large areas, this quantity of water results in considerably less required surface water storage, which saves capital costs. This design approach has been used successfully on multiple sites for over 30 years without failure.

scholarly journals Urine specific gravity as a diagnostic tool for dehydration in children

2010 ◽  
Vol 50 (5) ◽  
pp. 269 ◽  
Author(s):  
Kalis Joko Purwanto ◽  
Mohammad Juffrie ◽  
Djauhar Ismail
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Specific Gravity ◽  
Diagnostic Tool ◽  
Clinical Judgment ◽  
Plasma Osmolality ◽  
Body Weight Loss ◽  
Urine Osmolality ◽  
Urine Specific Gravity ◽  
Urine Production

Background Using clinical judgment to diagnose dehydration can be highly subjective. To diagnose dehydration, it would be ideal to have an accurate, inexpensive, objective and easy-to-perform diagnostic tool. In cases of dehydration, plasma osmolality rises, causing an increase in antidiuretic hormone (ADH) secretion. The increased ADH reduces urine production and increases urine osmolality. Previous studies have show that urine osmolality correlates well to urine specific gravity. We investigated if urine specific gravity can be a reliable and objective detennination of dehydration status.Objective To assess the accuracy of using urine specific gravity as a diagnostic tool to determine dehydration status of children with diarrhea.Methods We conducted the study in the pediatric ward of Sardjito Hospital from September 2009 to December 2009. Using a refractometer we measured urine specific gravity from patients with diarrhea. This measurement was then compared to a standard of acute body weight loss, with dehydration defined as weight loss of 5% or more. The cut-off value for defining dehydration using specific gravity measurements was detennined by a receiver-operator curve (ROC).Results Out of 61 pediatric patients who were recruited in this study, 18 (30%) had dehydration as defined by a body weight loss of 5% or more. Based on the ROC, we determined the cut off  value for urine specific gravity to be 1.022. Using this value, urine specific gravity was 72% sensitive (95% CI 52 to 93), and 84% specific (95% CI 73 to 95) in determining dehydration status.Conclusion Urine specific gravity is less accurate than clinical judgment in determining dehydration status in children with diarrhea.

scholarly journals Ionic Regulation and Water Balance in the Aquatic Larva of Sialis Lutaria

1955 ◽  
Vol 32 (2) ◽  
pp. 353-382 ◽  
Author(s):  
J. SHAW
Keyword(s):  
Water Balance ◽  
Electrolyte Composition ◽  
Sodium Ions ◽  
Ionic Regulation ◽  
Sodium Potassium ◽  
Water Excretion ◽  
Factors Affecting ◽  
Osmotic Water ◽  
Saline Solutions ◽  
Aquatic Larva

1. The electrolyte composition of the blood, tissues and excretory fluid of the aquatic larvae of Sialis lutaria has been measured, and the regulation of the concentrations of sodium, potassium and chloride in the blood studied in detail. 2. In the normal larvae these ions are not present in the excretory fluid. Potassium and, perhaps, sodium are reabsorbed in the rectum but chloride is never present in the rectum. 3. If these ions are present in the outside medium they are taken into the larvae through the gut. The blood concentration is regulated by the excretion of these ions via the rectal fluid. Potassium is rapidly excreted but chloride tends to be retained in the blood. Sodium is removed more rapidly than chloride. 4. Water enters the larvae by osmosis through the cuticle, but can also be absorbed through the gut by osmosis or together with sodium ions. The water intake is balanced by excretion of rectal fluid. The factors affecting the rate of water excretion have been studied. 5. The larvae are unable to survive in hypertonic saline solutions. This is due to their inability to make good osmotic water loss or to produce a hypertonic excretory fluid.

Estimation of water content by tritium dilution of animals subjected to rapid live-weight changes

1969 ◽  
Vol 72 (1) ◽  
pp. 31-40 ◽  
Author(s):  
W. R. McManus ◽  
R. K. Prichard ◽  
Carolyn Baker ◽  
M. V. Petruchenia
Keyword(s):  
Body Weight ◽  
Water Content ◽  
Total Body Water ◽  
Compensatory Growth ◽  
Specific Activity ◽  
Tritiated Water ◽  
Body Water ◽  
Under Nutrition ◽  
The Mean ◽  
Total Body

SUMMARYThe use of tritiated water to estimate total body-water content of animals experiencing recovery from under-nutrition was studied.The time for equilibration of tritiated water (TOH), given intraperitoneally, with total body water (TBW) was determined in rabbits and in rats. As judged by the specific activity of blood water, equilibration had occurred by 76–125 min in the rabbit and did not appear to be affected by the plane of nutrition. However, between slaughter groups the specific activity of water obtained from the liver 180 min after injection of TOH was significantly different from the specific activity of water simultaneously obtained from the blood plasma. It is concluded that the liver is not a suitable tissue to use for testing achievement of equilibration.As judged by the specific activity of blood water compared to that of water from the whole body macerate, equilibration in mature rats either in stable body condition or undergoing rapid compensatory growth occurred in less than 60 min.A trial comparing TOH-space (corrected by 3% body weight) and actual TBW (by desiccation) was conducted on thirty rabbits which experienced under-nutrition followed by compensatory growth.Prior to under-nutrition the agreement between actual and estimated TBW was satisfactory and within 2·3%. During compensatory growth the agreement was poor— the TOH values over-estimating actual TBW by about 12%.A trial with mature rats confirmed the findings with rabbits. For rats in stable body weight the mean estimated TOH-space for fourteen animals was within 1·2% of the actual TBW. For fourteen rats undergoing compensatory growth the mean estimated TOH-space (corrected by 3% body weight) overestimated actual TBW by 6·2%.

Water and solute permeability of rat lung caveolae: high permeabilities explained by acyl chain unsaturation

2005 ◽  
Vol 289 (1) ◽  
pp. C33-C41 ◽  
Author(s):  
Warren G. Hill ◽  
Eyad Almasri ◽  
W. Giovanni Ruiz ◽  
Gerard Apodaca ◽  
Mark L. Zeidel
Keyword(s):  
Water Permeability ◽  
Acyl Chain ◽  
Water Flux ◽  
High Water ◽  
Fatty Acyl ◽  
Rat Lung ◽  
Membrane Structures ◽  
Solute Permeability ◽  
Outer Leaflet ◽  
Osmotic Water

Caveolae are invaginated membrane structures with high levels of cholesterol, sphingomyelin, and caveolin protein that are predicted to exist as liquid-ordered domains with low water permeability. We isolated a caveolae-enriched membrane fraction without detergents from rat lung and characterized its permeability properties to nonelectrolytes and protons. Membrane permeability to water was 2.85 ± 0.41 × 10−3 cm/s, a value 5–10 times higher than expected based on comparisons with other cholesterol and sphingolipid-enriched membranes. Permeabilities to urea, ammonia, and protons were measured and found to be moderately high for urea and ammonia at 8.85 ± 2.40 × 10−7and 6.84 ± 1.03 × 10−2 respectively and high for protons at 8.84 ± 3.06 × 10−2 cm/s. To examine whether caveolin or other integral membrane proteins were responsible for high permeabilities, liposomes designed to mimic the lipids of the inner and outer leaflets of the caveolar membrane were made. Osmotic water permeability to both liposome compositions were determined and a combined inner/outer leaflet water permeability was calculated and found to be close to that of native caveolae at 1.58 ± 1.1 × 10−3 cm/s. In caveolae, activation energy for water flux was high (19.4 kcal/mol) and water permeability was not inhibited by HgCl2; however, aquaporin 1 was detectable by immunoblotting. Immunostaining of rat lung with AQP1 and caveolin antisera revealed very low levels of colocalization. We conclude that aquaporin water channels do not contribute significantly to the observed water flux and that caveolae have relatively high water and solute permeabilities due to the high degree of unsaturation in their fatty acyl chains.

The Water Balance of a Serpulid Polychaete, Mercierella Enigmatica (Fauvel)

1974 ◽  
Vol 60 (2) ◽  
pp. 321-330
Author(s):  
HELEN LE B. SKAER
Keyword(s):  
Body Weight ◽  
Water Balance ◽  
Blood Volume ◽  
Blood Concentration ◽  
Volume Regulation ◽  
Sea Water ◽  
External Medium ◽  
Wide Range ◽  
Natural Range ◽  
Passive Movements

1. The serpulid polychaete Mercierella enigmatica is found naturally in a wide range of salinities - from fresh water to 150% sea water (< 1-55‰ < 25.8-1421 mOsm). 2. Changes in body weight, blood volume and blood osmolality have been measured both during and after equilibration of animals with media of altered salinity. 3. The blood remains similar in osmolality to the external medium over a very wide range of salinity (43-1620 mOsm); osmoregulation occurs only at the lowest limit of the natural range. 4. Mercierella enigmatica shows volume regulation; after 4 days of equilibration with a medium of altered salinity the blood volume shows much less change than the blood concentration. 5. During equilibration there appear to be passive movements of both water and salts between the animals and their environment.

The structural basis for water exchange between the female cockroach (Blattella germanica) and her ootheca

2002 ◽  
Vol 205 (19) ◽  
pp. 2987-2996 ◽  
Author(s):  
Donald E. Mullins ◽  
K. June Mullins ◽  
Keith R. Tignor
Keyword(s):  
Water Balance ◽  
Water Exchange ◽  
Tritiated Water ◽  
Dark Field ◽  
Water Soluble ◽  
Structural Basis ◽  
Intimate Association ◽  
Low Humidity ◽  
Cockroach Blattella Germanica ◽  
Gravid Females

SUMMARY Female German cockroaches usually carry their oothecae until they hatch. The success of embryogenesis may be dependent on the water-balance relationship between females and their developing oothecae. Oothecae detached from females early in embryogenesis often fail to develop, especially in low-humidity environments. Experiments reported here using tritiated water have confirmed the transport of a significant amount of water to the ootheca from the female during embryogenesis; 18% of the tritiated water injected into gravid females was recovered in their oothecae after 24 h. We describe a structural basis of water absorption by the oothecae. An area located on the proximal end of the ootheca (adjacent to the `escutcheon-shaped vaginal imprint') contains small pores that penetrate the oothecal covering to access regions of the chorion lying beneath these pores. Experiments using microparabiotic chambers to examine transport of tritiated water and water-soluble materials across the escutcheon region of the oothecal covering, along with dark-field birefringent microscopy of the chorion, support the hypothesis that this chorionic network is capable of conducting water throughout the interior of the ootheca. Furthermore, the structural arrangement and intimate association of the female vestibulum with the oothecal pore field contained in the region of the escutcheon-shaped vaginal imprint appear to provide an efficient conduit to the chorion. The overall structural relationship might be a means for maintaining water balance between females and their oothecae during embryonic development. Evidence presented here supports observations that this species represents an important link in the transition from oviparity to ovoviviparity by internalization of cockroach oothecae.

Water Balance in Corixa Dentipes (Thoms.) (Hemiptera, Heteroptera)

1964 ◽  
Vol 41 (3) ◽  
pp. 609-619
Author(s):  
B. W. STADDON
Keyword(s):  
Water Balance ◽  
Osmotic Pressure ◽  
Water Intake ◽  
Ammonia Concentration ◽  
Ammonium Bicarbonate ◽  
Water Output

1. The water balance in Corixa dentipes (Thoms.) has been investigated under conditions of starvation in de-ionized water. 2. The rectal fluid was found to contain almost sufficient ammonium bicarbonate to account for the total osmotic pressure. It was invariably strongly hypotonic to the haemolymph. 3. The water output, as estimated by measuring the ammonia output and ammonia concentration of the rectal fluid, was shown to be appreciable but no connexion was found between the output of ammonia and of water. 4. Adults were shown to gain water by the mouth and some evidence was obtained that the cuticle may be an important route of water intake.

Measurement of total energy and material balance in rats by means of doubly labeled water

1960 ◽  
Vol 199 (2) ◽  
pp. 238-242 ◽  
Author(s):  
J. S. Lee ◽  
Nathan Lifson
Keyword(s):  
Body Weight ◽  
Water Intake ◽  
Material Balance ◽  
Body Water ◽  
Doubly Labeled Water ◽  
Final Body Weight ◽  
Water Output ◽  
Isotopic Analyses ◽  
The Difference ◽  
Metabolism Chamber

A test has been carried out in rats of the possibility of measuring with the aid of doubly labeled water (D2O18) the following components of the material balance of an animal: output of CO2 and water; intake of oxygen, food and water. The items of information used for the measurement were a) isotopic analyses of initial and final blood samples, b) composition of the diet with respect to percentage protein, carbohydrate and fat, c) initial and final body weight, d) final percentage body water. Initial percentage body water obtained from a by the volume of dilution principle could substitute for d. CO2 and water output were estimated isotopically; O2 consumption, from the CO2 output and dietary R. Q.; food intake, from CO2 output and dietary composition; water intake, from the difference between water output and dietary metabolic water. A rough correction for storage of materials was made from the change in body weight. The average difference between observed values for each of the above components of the material balance and values calculated by the isotope procedure was less than 10%. The fact that dry air was supplied to the animal in the metabolism chamber used to obtain the observed values probably favored better agreement between calculated and observed values for water intake and output than would prevail in ordinary moist air.

scholarly journals Evaluation of DSSAT soil-water balance module under cropped and bare soil conditions

2003 ◽  
Vol 46 (4) ◽  
pp. 489-498 ◽  
Author(s):  
Rogério Teixeira de Faria ◽  
Walter Truman Bowen
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Soil Water ◽  
Water Flux ◽  
Soil Water Potential ◽  
Bare Soil ◽  
Root Water Uptake ◽  
Soil Water Balance ◽  
Soil Conditions ◽  
Soil Water Flux

The performance of the soil water balance module (SWBM) in the models of DSSAT v3.5 was evaluated against soil moisture data measured in bare soil and dry bean plots, in Paraná, southern Brazil. Under bare soil, the SWBM showed a low performance to simulate soil moisture profiles due to inadequacies of the method used to calculate unsaturated soil water flux. Improved estimates were achieved by modifying the SWBM with the use of Darcy's equation to simulate soil water flux as a function of soil water potential gradient between consecutive soil layers. When used to simulate water balance for the bean crop, the modified SWBM improved soil moisture estimation but underpredicted crop yield. Root water uptake data indicated that assumptions on the original method limited plant water extraction for the soil in the study area. This was corrected by replacing empirical coefficients with measured values of soil hydraulic conductivity at different depths.

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