Effects of nest use, huddling, and torpor on thermal energetics of eastern pygmy-possums

2009 ◽  
Vol 31 (1) ◽  
pp. 31 ◽  
Author(s):  
Sae Namekata ◽  
Fritz Geiser
Keyword(s):  
Energy Expenditure ◽  
Ambient Temperature ◽  
Cold Exposure ◽  
Energy Use ◽  
Energy Costs ◽  
Energy Conserving ◽  
Thermal Energetics ◽  
Cercartetus Nanus ◽  
Reducing Energy

Eastern pygmy-possums (Cercartetus nanus) are known to be conservative with energy use probably because they rely on food that varies in availability. We quantified how nest use, huddling, and torpor contribute to a reduction of energy expenditure in C. nanus during mild cold exposure. In comparison to normothermic resting C. nanus at the same ambient temperature, nest use reduced energy expenditure on average by ~17%, huddling as a pair in a nest by ~50%, whereas torpor, which was employed by all seven individuals, lowered energy expenditure by >95%. Our study shows that while all energy-conserving strategies employed by these possums can contribute significantly to reducing energy expenditure, torpor is by far the most effective because it not only reduces thermoregulatory energy costs, but also energy expenditure required for maintenance processes.

Energy expenditure and respiratory activity of sheep during feeding

1966 ◽  
Vol 17 (3) ◽  
pp. 355 ◽  
Author(s):  
BA Young
Keyword(s):  
Energy Expenditure ◽  
Ambient Temperature ◽  
Energy Cost ◽  
Marked Reduction ◽  
Respiratory Activity ◽  
Energy Costs

Energy costs of feeding and respiratory changes during the ingestion of prepared rations were measured in experiments on penned sheep. Feeding energy increments per kilogram liveweight (increased energy expenditure attributable to the act of eating) ranged from 5.3 to 12.4 cal/min. Differences between sheep and between rations were not significant. Energy costs of eating (increased energy expenditure per gram of ration ingested) varied with the type of ration. A concentrate ration was ingested at an energy cost (per kg liveweight) of 0.3–0.6 cal/g ration, whereas chaff rations cost 1.2–1.9 cal/g ration. A marked reduction in respiratory frequencies and respiratory minute ventilations occurred during feeding whenever the pre-feeding respiratory activity was elevated due to the ambient temperature. When the respiration was eupnoeic before feeding there was a slight increase with feeding. While sheep were eating, respiratory frequencies ranged between 20 and 40 per minute and respiratory minute ventilations from 4.5 to 8.4 litres.

Ambient temperature effects on physiological traits of white-tailed deer

1975 ◽  
Vol 53 (6) ◽  
pp. 679-685 ◽  
Author(s):  
J. B. Holter ◽  
W. E. Urban Jr. ◽  
H. H. Hayes ◽  
H. Silver ◽  
H. R. Skutt
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Energy Expenditure ◽  
Ambient Temperature ◽  
Temperature Effects ◽  
Temperature Changes ◽  
Wind Chill ◽  
Ambient Temperatures ◽  
Energy Equilibrium ◽  
Body Energy

Six adult white-tailed deer (Odocoileus virginianus borealis) were exposed to 165 periods of 12 consecutive hours of controlled constant ambient temperature in an indirect respiration calorimeter. Temperatures among periods varied from 38 to 0 (summer) or to −20C (fall, winter, spring). Traits measured were energy expenditure (metabolic rate), proportion of time spent standing, heart rate, and body temperature, the latter two using telemetry. The deer used body posture extensively as a means of maintaining body energy equilibrium. Energy expenditure was increased at low ambient temperature to combat cold and to maintain relatively constant body temperature. Changes in heart rate paralleled changes in energy expenditure. In a limited number of comparisons, slight wind chill was combatted through behavioral means with no effect on energy expenditure. The reaction of deer to varying ambient temperatures was not the same in all seasons of the year.

Body temperature regulation and oxygen consumption in young chicks fed thyroid hormone

1991 ◽  
Vol 69 (7) ◽  
pp. 1842-1847 ◽  
Author(s):  
Gregory K. Snyder ◽  
Joseph R. Coelho ◽  
Dalan R. Jensen
Keyword(s):  
Oxygen Consumption ◽  
Thyroid Hormone ◽  
Body Temperature ◽  
Ambient Temperature ◽  
Cold Exposure ◽  
Elevated Serum ◽  
Body Temperatures ◽  
Serum Thyroid Hormone ◽  
Regulate Body Temperature ◽  
Young Chicks

In chicks the ability to regulate body temperature to adult levels develops during the first 2 weeks of life. We examined whether the ability of young chicks to regulate body temperature is increased by elevated levels of the thyroid hormone 3,3′5-triiodothyronine. By 13 days following hatch, body temperatures of chicks were not significantly different from those expected for adult birds. Furthermore, at an ambient temperature of 10 °C, 13-day-old control chicks were able to maintain body temperature, and elevated serum thyroid hormone levels did not increase rates of oxygen consumption or body temperature above control values. Six-day-old chicks had body temperatures that were significantly lower than those of the 13-day-old chicks and were not able to regulate body temperature when exposed to an ambient temperature of 10 °C. On the other hand, 6-day-old chicks with elevated serum thyroid hormone had significantly higher rates of oxygen consumption than 6-day-old control chicks, and were able to maintain constant body temperatures during cold exposure. The increased oxygen consumption rates and improved ability to regulate body temperature during cold exposure were correlated with increased citrate synthase activity in skeletal muscle. Our results support the argument that thyroid hormones play an important role in the development of thermoregulatory ability in neonate birds by stimulating enzyme activities associated with aerobic metabolism.

scholarly journals Resting Energy Expenditure and Cold Induced Thermogenesis in Patients with Overt Hyperthyroidism

2021 ◽  
Author(s):  
Claudia Irene Maushart ◽  
Jaël Rut Senn ◽  
Rahel Catherina Loeliger ◽  
Judith Siegenthaler ◽  
Fabienne Bur ◽  
...  
Keyword(s):  
Body Composition ◽  
Energy Expenditure ◽  
Skin Temperature ◽  
Cold Exposure ◽  
Resting Energy Expenditure ◽  
Free T4 ◽  
Free T3 ◽  
Euthyroid State ◽  
Overt Hyperthyroidism ◽  
Resting Energy

Abstract Context Thyroid hormone is crucial for the adaptation to cold. Objective To evaluate the effect of hyperthyroidism on resting energy expenditure (REE), cold-induced thermogenesis (CIT) and changes in body composition and weight. Design Prospective cohort study. Setting Endocrine outpatient clinic at tertiary referral center. Patients Eighteen patients with overt hyperthyroidism. Main Outcome Measures We measured REE during hyperthyroidism, after restoring euthyroid TH levels and after 3 months of normal thyroid function. In fourteen patients energy expenditure (EE) was measured before and after a mild cold exposure of two hours and CIT was the difference between EEcold and EEwarm. Skin temperatures at eight positions were recorded during the study visits. Body composition was assessed by dual X-ray absorption. Results Free T4 (fT4) and free T3 (fT3) decreased significantly over time (fT4, p=0.0003; fT3, p=0.0001). REE corrected for lean body mass (LBM) decreased from 42 ± 6.7 kcal/24h/kg LBM in the hyperthyroid to 33±4.4 kcal/24h/kg LBM (-21%, p<0.0001 vs hyperthyroid) in the euthyroid state and three months later to 33 ± 5.2 kcal/24h/kg LBM (-21%, p=0.0022 vs. hyperthyroid, overall p<0.0001). Free T4 (p=0.0001) and free T3 (p<0.0001) were predictors of REE. CIT did not change from the hyperthyroid to the euthyroid state (p=0.96). Hyperthyroidism led to increased skin temperature at warm ambient conditions but did not alter core body temperature, nor skin temperature after cold exposure. Weight regain and body composition were not influenced by REE and CIT during the hyperthyroid state. Conclusions CIT is not increased in patients with overt hyperthyroidism.

scholarly journals ENERGY EFFICIENCY IN RESIDENTIAL BUILDINGS, LESS STRAIGHT FORWARD THEN PRESUMED

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Hugo Hens
Keyword(s):  
Energy Efficiency ◽  
Energy Efficient ◽  
Energy Use ◽  
Low Voltage ◽  
Residential Buildings ◽  
Primary Energy ◽  
Heating And Cooling ◽  
Net Zero ◽  
Energy Conserving ◽  
New Construction

Since the 1990s, the successive EU directives and related national or regional legislations require new construction and retrofits to be as much as possible energy-efficient. Several measures that should stepwise minimize the primary energy use for heating and cooling have become mandated as requirement. However, in reality, related predicted savings are not seen in practice. Two effects are responsible for that. The first one refers to dweller habits, which are more energy-conserving than the calculation tools presume. In fact, while in non-energy-efficient ones, habits on average result in up to a 50% lower end energy use for heating than predicted. That percentage drops to zero or it even turns negative in extremely energy-efficient residences. The second effect refers to problems with low-voltage distribution grids not designed to transport the peaks in electricity whensunny in summer. Through that, a part of converters has to be uncoupled now and then, which means less renewable electricity. This is illustrated by examples that in theory should be net-zero buildings due to the measures applied and the presence of enough photovoltaic cells (PV) on each roof. We can conclude that mandating extreme energy efficiency far beyond the present total optimum value for residential buildings looks questionable as a policy. However, despite that, governments and administrations still seem to require even more extreme measurements regarding energy efficiency.

scholarly journals Validating accelerometry-derived proxies of energy expenditure using the doubly-labelled water method in the smallest penguin species

Biology Open ◽  
2021 ◽  
pp. bio.055475
Author(s):  
G. J. Sutton ◽  
J. A. Botha ◽  
J. R. Speakman ◽  
J. P. Y. Arnould
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Energy Use ◽  
Travel Speed ◽  
Specific Energy Expenditure ◽  
Doubly Labelled Water ◽  
Data Collection And Analysis ◽  
Behavioural Patterns ◽  
Free Ranging ◽  
The Relationship

Understanding energy use is central to understanding an animal's physiological and behavioural ecology. However, directly measuring energy expenditure in free-ranging animals is inherently difficult. The doubly-labelled water (DLW) method is widely used to investigate energy expenditure in a range of taxa. Although reliable, DLW data collection and analysis is both financially costly and time consuming. Dynamic body acceleration (e.g. VeDBA) calculated from animal-borne accelerometers has been used to determine behavioural patterns, and is increasingly being used as a proxy for energy expenditure. Still its performance as a proxy for energy expenditure in free-ranging animals is not well established and requires validation against established methods. In the present study, the relationship between VeDBA and the at-sea metabolic rate calculated from DLW was investigated in little penguins (Eudyptula minor) using three approaches. Both in a simple correlation and activity-specific approaches were shown to be good predictors of at-sea metabolic rate. The third approach using activity-specific energy expenditure values obtained from literature did not accurately calculate the energy expended by individuals. However, all three approaches were significantly strengthened by the addition of mean horizontal travel speed. These results provide validation for the use of accelerometry as a proxy for energy expenditure and show how energy expenditure may be influenced by both individual behaviour and environmental conditions.

Auxiliary Heating of the Hands during Cold Exposure and Manual Performance

1971 ◽  
Vol 13 (5) ◽  
pp. 457-465 ◽  
Author(s):  
John M. Lockhart ◽  
Harold O. Kiess
Keyword(s):  
Ambient Temperature ◽  
Cold Exposure ◽  
Auxiliary Heating ◽  
Knot Tying ◽  
Performance Tasks ◽  
Impaired Performance ◽  
Ambient Temperature Condition ◽  
Significant Performance ◽  
Manual Tasks ◽  
Manual Performance

Twenty subjects performed five manual tasks barehanded during exposure to a 60°-F ambient temperature control condition, a 0°-F condition, and three ambient temperature conditions of 20°, 0°, and −20° F, in which auxiliary heat was applied to the hands. The tasks consisted of the Purdue Pegboard assembly, block-stringing, Minnesota Rate of Manipulation placing, knot-tying, and screw-tightening tasks and were performed after exposure durations of 0, 60, 120, and 180 min. Exposure to the 0°-F condition without auxiliary heat resulted in significant performance decrements on all tasks. The application of auxiliary heat to the hands resulted in the avoidance or alleviation of impaired performance during cold exposure depending upon the task, ambient temperature condition, and duration of exposure. The differential effects of auxiliary heat during cold exposure across manual performance tasks were related to the effects of auxiliary heat on hand skin temperature. These effects are discussed in terms of differential hand and finger dexterity, strength, and speed of movement requirements across tasks.

Analyzing the Performance of Ceramic Kiln by Using Thermal Image Technique for Reducing Energy Costs

2018 ◽  
Vol 766 ◽  
pp. 7-12
Author(s):  
Siwat Lawanwadeekul ◽  
Mattika Bunma
Keyword(s):  
Thermal Efficiency ◽  
Research Area ◽  
Thermal Image ◽  
Energy Costs ◽  
Thermal Camera ◽  
Depth Interview ◽  
Liquid Petroleum Gas ◽  
Image Technique ◽  
Reducing Energy

The aim of this research was to find a way to reduce energy costs by using thermal image techniques for investigating the thermal efficiency of ceramic furnaces. The case study was “Ban Nam Jo Ceramic”. The researchers collected the information by performing an in-depth interview at the research area, collecting preliminary data and using the thermal camera in the technical analysis part. The researchers also measured the temperature and volume of gas in the furnace. After that, those data were used to calculate the energy balance and the thermal efficiency of ceramic kilns. The data showed that the first measured furnace had calculated thermal efficiency of 9.99%. After the maintenance, the thermal efficiency increased to 16.64%. Furthermore, the volume of liquid petroleum gas decreased by 40%, and the damage in products after firing decreased by 3 %.

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