Factors Altering Spiracle Control in Adult Dragonflies: Water Balance

1964 ◽  
Vol 41 (2) ◽  
pp. 331-343
Author(s):  
P. L. MILLER
Keyword(s):  
Carbon Dioxide ◽  
Water Balance ◽  
Osmotic Pressure ◽  
Marked Variation ◽  
In The Wild ◽  
Degree Of Control

1. Dragonflies caught in the wild display a marked variation in the degree of control exercised over their spiracles. 2. In the laboratory desiccation produces tighter control and hydration looser control of spiracle 2: that is, in a partially desiccated insect the thresholds of the spiracular responses to carbon dioxide and to oxygen lack are raised. 3. In desiccated insects the frequency of motor impulses to the spiracles is higher than in hydrated individuals. These effects can be reproduced by perfusion with physiological salines of various strengths. 4. The reaction does not depend on the osmotic pressure of the solution but on the concentration of one or more of its constituents. 5. The isolated mesothoracic ganglion is able to mediate this reaction.

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.

Water Balance and Kidney Function in Four Species of Rattus From Ecologically Diverse Environments.

1976 ◽  
Vol 24 (1) ◽  
pp. 7 ◽  
Author(s):  
PR Baverstock
Keyword(s):  
Drinking Water ◽  
Water Balance ◽  
Osmotic Pressure ◽  
Individual Variation ◽  
Water Deprivation ◽  
High Metabolic Rate ◽  
Sodium Potassium ◽  
Rattus Fuscipes ◽  
Microhabitat Preferences ◽  
Urine Concentrating Ability

While Rattus fuscipes survived only 4 days of water deprivation at 21�C, R. norvegicus, R. villosissimus and R. lutreolus survived 13-16 days. There was considerable inter-individual variation in the response of water-deprived R. villosissimus. Analysis of osmotic pressure, urea, sodium, potassium and chloride of both plasma and urine of rats with and without drinking water revealed that: (1) the abilities of R. norvegicus and R. villosissimus to tolerate water deprivation were due in large part to their abilities to produce highly concentrated urine; (2) R. lutreolus tolerated long periods of water deprivation not by urine-concentrating ability but by partly abandoning homeostasis and tolerating elevated levels of plasma solutes; (3) water-deprived R. fuscipes excreted large volumes of concentrated urine, possibly because their relatively high metabolic rate necessitated the excretion of excess metabolites. In all of the rats, urea constituted an unusually low proportion of the total osmotic pressure. The water-balance response of water-deprived rats is at variance with both their macrogeographical distribution and microhabitat preferences.

Rectal Absorption in the Desert Locust, Schistocherca Gregaria Forskål

1964 ◽  
Vol 41 (1) ◽  
pp. 69-80
Author(s):  
J. E. PHILLIPS
Keyword(s):  
Water Balance ◽  
Osmotic Pressure ◽  
Schistocerca Gregaria ◽  
Tap Water ◽  
Ionic Concentration ◽  
Malpighian Tubules ◽  
Desert Locust ◽  
Ionic Regulation ◽  
Rectal Absorption ◽  
Salt And Water Balance

1. The physiology of the excretory system and its role in salt and water balance have been studied in the desert locust, Schistocerca gregaria. 2. Collections and analyses were made of hindgut fluid (derived from the Malpighian tubules) and rectal fluid from locusts kept under various dietary régimes. 3. In starved locusts supplied with tap water very little fluid accumulates in the rectum, the output of the Malpighian tubules being almost completely reabsorbed. Relatively more salt than water is reabsorbed with the result that the rectal fluid attains a lower ionic concentration but higher osmotic pressure than the haemolymph. No fluid is voided. 4. In starved locusts supplied with hypertonic saline the rectum is distended with, fluid which has an osmotic pressure and ionic concentration considerably above that of the haemolymph. Very little fluid is voided. 5. Substantial elimination of fluid from the rectum occurs only in fed locusts, in association with the voiding of faeces. 6. These results are discussed in relation to the mechanism of osmotic and ionic regulation.

Do nonhuman animals reason about prestige-based status?

2021 ◽  
Author(s):  
Tara M Mandalaywala
Keyword(s):  
Social Learning ◽  
Cultural Transmission ◽  
Experimental Methods ◽  
Comparative Approach ◽  
High Status ◽  
Marked Variation ◽  
Selective Pressures ◽  
Nonhuman Animals ◽  
In The Wild ◽  
Nonhuman Species

Status is a complex, but crucially important, aspect of life across species. In recent decades, researchers have made significant contributions to our understanding of both the pathways by which status can be attained, as well as our underlying capacities for reasoning about these pathways. In 2001, Henrich & Gil-White proposed a prestige-based pathway to status where low status actors willingly defer to competent or knowledgeable high status actors, as a means of facilitating social learning and cultural transmission. Although this type of status hierarchy, and the capacity to reason about it, was hypothesized to be unique to humans, here I argue that there are several reasons why we might observe prestige-based status, and the capacity for reasoning about this pathway to status, in some nonhuman species as well. These reasons focus on the prevalence, importance, and sophistication of social learning in certain taxa, as well as the marked variation in hierarchy characteristics and structure across species. I point out places where our current methodologies encounter difficulties distinguishing whether a hierarchy in the wild is based on dominance or prestige, where our experimental methods leave us unable to assess whether an individual is reasoning about a high status actor as being prestigious or formidable, and provide suggestions for addressing these limitations. Adopting a comparative approach will clarify whether prestige-based status truly is unique to humans, and—if not—precisely what selective pressures facilitate the emergence of prestige-based status and the capacity for reasoning about it.

Chemical Characterization of Sardine Meat Powder Produced by Dehydration with High Osmotic Pressure Resin and Defatting with High Pressure Carbon Dioxide

1989 ◽  
Vol 54 (2) ◽  
pp. 265-268 ◽  
Author(s):  
KENSHIRO FUJIMOTO ◽  
YASUSHI ENDO ◽  
SOON-YEONG CHO ◽  
RITSUKO WATABE ◽  
YASUO SUZUKI ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Osmotic Pressure ◽  
Chemical Characterization

Infra-red spectra of muscle

1952 ◽  
Vol 139 (897) ◽  
pp. 526-527 ◽  
Keyword(s):  
Water Balance ◽  
Osmotic Pressure ◽  
Sea Water ◽  
Urine Volume ◽  
The Body ◽  
Fluid Distribution ◽  
Common Mechanism ◽  
Distilled Water ◽  
Body Protein ◽  
The Third

Three rations, 350 ml. distilled water, 250 ml. distilled water plus 96·5 g carbohydrate, and 350 ml. distilled water plus 150 ml. sea water, were given daily for 3-day periods to six subjects receiving no other food or drink. The experiment was fully ‘crossed-over' and was carried out in a constant environment. On the carbohydrate ration the water balance over the third day of exposure was about 200 ml. better than on the ration consisting of water only, and the rise in the total osmotic pressure of the body was smaller. The improvement in water balance was the result of a reduction in urine volume, which was in turn due to the effects of carbohydrate upon meta­bolism. These effects were (1) the sparing of body protein, (2) the prevention of ketosis and (3) a reduction of the basal metabolic rate. It is suggested that all three may have been brought about by a common mechanism. On the sea-water ration the water balance for the third day was improved by 80 to 150 ml., but the rise in the osmotic pressure of the body was greater than when distilled water alone was given. These effects were due to the retention of most of the water of the sea water, together with the salt which it contained. It is suggested that the effects of sea-water drinking on body tonicity and fluid distribution are deleterious, and that the gain of water observed on the third day would eventually have been replaced by a loss.

Advances in hydrological modelling with the Budyko framework

2016 ◽  
Vol 40 (3) ◽  
pp. 409-430 ◽  
Author(s):  
Cong Wang ◽  
Shuai Wang ◽  
Bojie Fu ◽  
Lu Zhang
Keyword(s):  
Climate Change ◽  
Water Balance ◽  
Anthropogenic Activities ◽  
Catchment Scale ◽  
Data Set ◽  
Landscape Characteristics ◽  
Temporal And Spatial Variability ◽  
Terrestrial Water ◽  
Physical Background ◽  
Degree Of Control

Substantial climate change and intensive anthropogenic activities hamper efforts to explain and predict the variability of the terrestrial water balance. The Budyko framework has recently seen a renaissance in hydrological research due to the framework’s comprehensiveness and effectiveness for studying the effects of global change on water resources. In this paper, the development of the Budyko framework is analysed first. The temporal and spatial variability for the Budyko hypothesis are subsequently elaborated. On finer temporal scales, more processes need to be considered, and the degree of control exerted by individual factors on the water balance varies with the spatial scale considered. Finally, perspectives regarding better understanding and application of the Budyko framework at the catchment scale are provided. A representative and diverse catchment data set is required to estimate the parameter in the model. The co-evolution of landscape characteristics and climate properties would be beneficial to improve the Budyko framework with respect to model parsimony and the physical background. It is necessary to illuminate how the empirical Budyko curve would change under climate change. The general laws for selecting variables and statistical methods for improving Budyko models still need to be explored.

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