scholarly journals DISCONTINUOUS CARBON DIOXIDE RELEASE IN THE EASTERN LUBBER GRASSHOPPER ROMALEA GUTTATA AND ITS EFFECT ON RESPIRATORY TRANSPIRATION

1993 ◽  
Vol 177 (1) ◽  
pp. 169-180 ◽  
Author(s):  
N. F. Hadley ◽  
M. C. Quinlan
Keyword(s):  
Water Loss ◽  
Cycle Duration ◽  
Total Water ◽  
Lubber Grasshopper ◽  
Romalea Guttata ◽  
Adult Insect ◽  
Carbon Dioxide Release ◽  
Burst Phase ◽  
Increasing Temperature ◽  
Range Of Values

Ventilatory patterns were examined in the Eastern lubber grasshopper Romalea guttata and correlated with respiratory transpiration. Discontinuous release of CO2 was only observed in quiescent individuals during their scotophase. Interburst periods (spiracles closed) alternated with bouts of CO2 emission and O2 consumption (burst phase); no true ‘flutter’ phase was observed. Cycle duration decreased with increasing temperature in both hydrated and dehydrated individuals. Metabolic rates for this large, sluggish species are lower than those reported for smaller and/or more active grasshoppers. Water loss rates fell within an expected range of values for arthropods from mesic environments. Respiratory transpiration accounted for only 1.9-3.9 % of the total water loss between 15 and 30 sC and for only 7 % of the water loss during the burst phase of the cycle. These data indicate that the cyclic release of CO2 in this adult insect does not result in substantial savings of water.

scholarly journals Intra-individual variation allows an explicit test of the hygric hypothesis for discontinuous gas exchange in insects

2009 ◽  
Vol 6 (2) ◽  
pp. 274-277 ◽  
Author(s):  
Caroline M. Williams ◽  
Shannon L. Pelini ◽  
Jessica J. Hellmann ◽  
Brent J. Sinclair
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Metabolic Rate ◽  
Water Loss ◽  
Individual Variation ◽  
Loss Reduction ◽  
Total Water ◽  
Explicit Test ◽  
Carbon Dioxide Release ◽  
Flow Through

The hygric hypothesis postulates that insect discontinuous gas exchange cycles (DGCs) are an adaptation that reduces respiratory water loss (RWL), but evidence is lacking for reduction of water loss by insects expressing DGCs under normal ecological conditions. Larvae of Erynnis propertius (Lepidoptera: Hesperiidae) naturally switch between DGCs and continuous gas exchange (CGE), allowing flow-through respirometry comparisons of water loss between the two modes. Water loss was lower during DGCs than CGE, both between individuals using different patterns and within individuals using both patterns. The hygric cost of gas exchange (water loss associated with carbon dioxide release) and the contribution of respiratory to total water loss were lower during DGCs. Metabolic rate did not differ between DGCs and CGE. Thus, DGCs reduce RWL in E. propertius , which is consistent with the suggestion that water loss reduction could account for the evolutionary origin and/or maintenance of DGCs in insects.

scholarly journals Transepidermal Water Loss after Water Immersion

2021 ◽  
Vol 73 (6) ◽  
pp. 386-390
Author(s):  
Rattanavalai Nitiyarom ◽  
Nampen Siriwat ◽  
Wanee Wisuthsarewong
Keyword(s):  
Healthy Volunteers ◽  
Water Loss ◽  
Water Immersion ◽  
Transepidermal Water Loss ◽  
Total Water ◽  
Previous Period ◽  
Cumulative Percentage ◽  
Significant Difference ◽  
Males And Females

Objective: To observe changes in transepidermal water loss (TEWL) at different times after water immersion.Materials and Methods: TEWL values were measured before water immersion and at 3, 5, 10, 15, 20, and 30 minutes after immersion of the skin in water for 5 minutes.Results: Forty-one healthy volunteers were enrolled with an average age of 30.4±5.5 years. Twenty-five subjects were female and sixteen were male. The TEWL value before water immersion (TEWLbaseline) was 13.16±7.27 g/m2/h and TEWL values at 3, 5, 10, 15, 20 and 30 minutes after immersion were 23.21±7.67, 16.12±3.42, 14.76±6.36, 14.45±6.67, 13.53±4.67 and 12.96±5.18 g/m2/h, respectively. After immersion, TEWL values at 3 and 5 minutes statistically increased compared to TEWLbaseline (p<0.001). TEWL values between 10 to 30 minutes gradually dropped with no statistically significant difference compared to the previous period and TEWLbaseline. Although total water loss from the skin occurred within 30 minutes, 56.9% of it occurred within 10 minutes after immersion. There was no significant difference between TEWLbaseline in males and females but the TEWL values at 3, 5 and 15 minutes after immersion in males was higher than in females (p<0.05). Conclusion: TEWL statistically increased after water immersion for only 5 minutes. The cumulative percentage of TEWL was high within 10 minutes. Gender did not affect TEWL values before immersion; however, males experienced more water loss from the skin than females after immersion. Therefore, moisturizer should be applied immediately before TEWL occurs.

Evaluation of seasonality on total water intake, water loss and water balance in the general population in Greece

2013 ◽  
Vol 26 ◽  
pp. 90-96 ◽  
Author(s):  
O. Malisova ◽  
V. Bountziouka ◽  
D. Β. Panagiotakos ◽  
A. Zampelas ◽  
M. Kapsokefalou
Keyword(s):  
General Population ◽  
Water Balance ◽  
Water Intake ◽  
Water Loss ◽  
Total Water ◽  
Intake Water ◽  
Total Water Intake

scholarly journals Impact of Biocontainers With and Without Shuttle Trays on Water Use in the Production of a Containerized Ornamental Greenhouse Crop

2015 ◽  
Vol 25 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Michael R. Evans ◽  
Andrew K. Koeser ◽  
Guihong Bi ◽  
Susmitha Nambuthiri ◽  
Robert Geneve ◽  
...  
Keyword(s):  
Catharanthus Roseus ◽  
Water Loss ◽  
Wood Fiber ◽  
Dairy Manure ◽  
Rice Hull ◽  
Total Water ◽  
Coconut Fiber ◽  
Irrigation Interval ◽  
Plastic Containers ◽  
Reduced Water

Nine commercially available biocontainers and a plastic control were evaluated at Fayetteville, AR, and Crystal Springs, MS, to determine the irrigation interval and total water required to grow a crop of ‘Cooler Grape’ vinca (Catharanthus roseus) with or without the use of plastic shuttle trays. Additionally, the rate at which water passed through the container wall of each container was assessed with or without the use of a shuttle tray. Slotted rice hull, coconut fiber, peat, wood fiber, dairy manure, and straw containers were constructed with water-permeable materials or had openings in the container sidewall. Such properties increased the rate of water loss compared with more impermeable bioplastic, solid rice hull, and plastic containers. This higher rate of water loss resulted in most of the biocontainers having a shorter irrigation interval and a higher water requirement than traditional plastic containers. Placing permeable biocontainers in plastic shuttle trays reduced water loss through the container walls. However, irrigation demand for these containers was still generally higher than that of the plastic control containers.

scholarly journals The scaling of carbon dioxide release and respiratory water loss in flying fruit flies (Drosophila spp.)

2000 ◽  
Vol 203 (10) ◽  
pp. 1613-1624 ◽  
Author(s):  
F.O. Lehmann ◽  
M.H. Dickinson ◽  
J. Staunton
Keyword(s):  
Carbon Dioxide ◽  
Body Size ◽  
Water Loss ◽  
Visual Motion ◽  
Bulk Water ◽  
Fruit Flies ◽  
Specific Rate ◽  
Allometric Exponent ◽  
Flying Insects ◽  
Carbon Dioxide Release

By simultaneously measuring carbon dioxide release, water loss and flight force in several species of fruit flies in the genus Drosophila, we have investigated respiration and respiratory transpiration during elevated locomotor activity. We presented tethered flying flies with moving visual stimuli in a virtual flight arena, which induced them to vary both flight force and energetic output. In response to the visual motion, the flies altered their energetic output as measured by changes in carbon dioxide release and concomitant changes in respiratory water loss. We examined the effect of absolute body size on respiration and transpiration by studying four different-sized species of fruit flies. In resting flies, body-mass-specific CO(2) release and water loss tend to decrease more rapidly with size than predicted according to simple allometric relationships. During flight, the mass-specific metabolic rate decreases with increasing body size with an allometric exponent of −0.22, which is slightly lower than the scaling exponents found in other flying insects. In contrast, the mass-specific rate of water loss appears to be proportionately greater in small animals than can be explained by a simple allometric model for spiracular transpiration. Because fractional water content does not change significantly with increasing body size, the smallest species face not only larger mass-specific energetic expenditures during flight but also a higher risk of desiccation than their larger relatives. Fruit flies lower their desiccation risk by replenishing up to 75 % of the lost bulk water by metabolic water production, which significantly lowers the risk of desiccation for animals flying under xeric environmental conditions.

scholarly journals The use of Frontier Analysis to assess the technical rigor of water loss performance indicators

2020 ◽  
Vol 3 (1) ◽  
pp. 102-117
Author(s):  
Alan S. Wyatt
Keyword(s):  
North America ◽  
Best Practices ◽  
Water Loss ◽  
Performance Indicators ◽  
Total Water ◽  
Water Losses ◽  
Frontier Analysis ◽  
Water Association ◽  
International Water ◽  
And Performance

Abstract The American Water Works Association (AWWA) has developed and disseminated advanced methods and performance indicators for assessing and reducing water losses in North America, based in large part on the methods and indicators developed by the International Water Association (IWA). However, many utilities and regulators still use the old, inaccurate, %NRW indicator. A robust, quantitative assessment of the technical rigor of water loss indicators was needed but could not be found in the literature. So, an innovative approach was developed, using Frontier Analysis which provided such a score of ‘technical rigor’. This paper presents this method, applied to three datasets from North America, assessing 15 candidate indicators for total water losses, apparent losses and real losses. The results provide quantitative ‘scores’ of the technical rigor of the candidate indicators. Indicators with relatively high scores align with indicators used in the IWA best practices. Other indicators, such as the %NRW indicator, were found to have low technical rigor. The conclusion of the paper summarizes the rigorous indicators, and suggests areas for further application of this method, and for further research.

scholarly journals Water Use of Container-grown Geraniums and Petunias

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 839C-839
Author(s):  
Karen L. Panter
Keyword(s):  
Plant Height ◽  
Water Use ◽  
Water Loss ◽  
Final Height ◽  
Dry Weight ◽  
Pot Experiment ◽  
Total Water ◽  
Plant Weight ◽  
Growing Medium ◽  
Bedding Plant

Two studies were undertaken to quantify the amount of water used by two container-grown bedding plant crops. Petunia × hybrida cv. Welby Blue and Pelargonium × hortorum cv Red Satisfaction plants were grown in 11-cm pots in a commercial greenhouse in Denver, Colo. In Expt. 1, rooted geranium cuttings and petunia seedlings were planted in Fafard #2, a growing medium containing peat, perlite, and vermiculite. Half of the plants were grown with the substrate covered. Each pot was weighed just prior to, and again 24 h, after watering. Measured amounts of water were applied to the pots. Geraniums in uncovered pots lost an average of 1.7 kg/pot over 59 days. Geraniums in covered pots lost an average of 1.6 kg/pot. Petunias, over 23 days, lost 730 g per uncovered pot and 623 g per covered pot. Experiment 2 compared water loss in growing medium amended with five different hydrophilic gels, and a control with no gel added. With geraniums, no differences were found among treatments in total water loss, initial or final plant height, or fresh or dry plant weight. With petunias, no differences occurred in initial or final height, or fresh or dry weight. There was a difference between two of the gel treatments in total amount of weight lost.

Water Relations of the Desert Scorpion, Hadrurus Arizonensis

1970 ◽  
Vol 53 (3) ◽  
pp. 547-558 ◽  
Author(s):  
NEIL F. HADLEY
Keyword(s):  
Water Loss ◽  
Temperature Curve ◽  
Total Water ◽  
World Species ◽  
Cuticular Transpiration ◽  
Hadrurus Arizonensis ◽  
Cuticular Permeability ◽  
Hydration State ◽  
Lower Saturation ◽  
Loss Rates

1. Total water-loss rates for Hadrurus arizonensis (0.028% wt/h at 30 °C in dry air) are comparable to rates for Old World species and are well below rates for other desert arthropods under similar conditions. 2. Cuticular and respiratory transpiration constitute the two major avenues of water loss, cuticular water loss predominating at temperatures up to approximately 38 °C and respiratory transpiration predominating at temperatures above 40 °C. 3. The cuticular transpiration/temperature curve exhibits a two-plateau configuration with abrupt increases in cuticular permeability occurring between 35 and 40 °C and between 65 and 70 °C 4. Cuticular water-loss values in dead scorpions exceed those of total water loss in living scorpions. The increased cuticular permeability after death is interpreted as evidence for the existence of an active cuticular water-retaining mechanism. 5. Water-loss rates are significantly reduced at lower saturation deficits; however, scorpions are unable to absorb significant quantities of water from near-saturated atmospheres or moist substrates, regardless of their hydration state. 6. The importance of water conserving versus water regaining mechanisms are discussed in relation to the total adaptations of these animals to hot, dry environments.

Hydraulic constraints and stomatal optimization

2021 ◽  
Author(s):  
Thomas Buckley
Keyword(s):  
Stomatal Conductance ◽  
Analytical Solution ◽  
Water Transport ◽  
Water Loss ◽  
Total Carbon ◽  
Carbon Gain ◽  
Total Water ◽  
Water Potentials ◽  
Hydraulic Vulnerability ◽  
Alternative Approaches

&lt;p&gt;The classical Cowan-Farquhar approach to identifying optimal stomatal conductance treats total water loss as an imposed constraint. That approach can conflict, both physically and economically, with biophysical constraints on water transport. In this talk, I will illustrate these conflicts and discuss alternative approaches -- recently pioneered by Sperry, Wolf, Eller, and their colleagues -- that aim to penalize excessive transpiration by explicitly incorporating hydraulic risk, using hydraulic vulnerability curves (VCs). In this context, I will present preliminary efforts to determine whether VCs accurately reflect the actual probabilistic risk posed by low water potentials (that is, the expected reduction in total carbon gain), as well as an extension to the recent analytical solution by Eller et al.&lt;/p&gt;

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