Effect of roost choice on winter torpor patterns of a free-ranging insectivorous bat

2016 ◽  
Vol 64 (2) ◽  
pp. 132 ◽  
Author(s):  
Clare Stawski ◽  
Shannon E. Currie
Keyword(s):  
Ambient Temperature ◽  
Skin Temperature ◽  
Agricultural Landscape ◽  
Wide Distribution ◽  
Cold Weather ◽  
Internal Cavity ◽  
Thermal Physiology ◽  
Ambient Conditions ◽  
Tree Cavity ◽  
Free Ranging

Gould’s wattled bat (Chalinolobus gouldii) is one of only three native Australian mammals with an Australia-wide distribution. However, currently no data are available on the thermal physiology of free-ranging C. gouldii. Therefore, we aimed to quantify the effect of roost choice on daily skin temperature fluctuations during winter in C. gouldii living in an agricultural landscape in a temperate region. Ambient conditions consisted of long periods below 0°C and snow. Some individuals roosted high in dead branches whereas one individual roosted in a large cavity located low in a live tree. Torpor was employed on every day of the study period by all bats, with bouts lasting for over five days. The skin temperature of individuals in the dead branches tracked ambient temperature, with skin temperatures below 3°C on 67% of bat-days (lowest recorded –0.2°C). In contrast, the individual in the tree cavity maintained a larger skin-ambient temperature differential, likely influenced by the internal cavity temperature. Our study presents the lowest skin temperature recorded for a free-ranging Australian microbat and reveals that roost choice affects the thermal physiology of C. gouldii, ensuring survival during periods of cold weather and limited food supply.

scholarly journals The effect of calf jackets on the health, performance, and skin temperature of dairy origin beef calves

2019 ◽  
Vol 4 (1) ◽  
pp. 316-323 ◽  
Author(s):  
Naomi H Rutherford ◽  
Alan W Gordon ◽  
Gareth Arnott ◽  
Francis O Lively
Keyword(s):  
Ambient Temperature ◽  
Skin Temperature ◽  
Disease Incidence ◽  
Live Weight ◽  
Climatic Conditions ◽  
Ambient Conditions ◽  
Beef Calves ◽  
Calf Health ◽  
Health Performance ◽  
Humidity Index

Abstract Variations and extremities in climatic conditions can result in cold stress for dairy calves during the preweaning period. The objective of this study was to investigate the effect of calf jackets on the health, performance, and skin temperature of dairy-origin beef calves. This study took place in a designated calf rearing unit, spanned for a duration of 1 yr, and consisted of five batches of calves. Calves (30.9 ± 1.68 d of age; 55.9 ± 0.20 kg live weight) were assigned to one of four treatment groups on arrival at the rearing unit. Treatments consisted of control (no jacket), arrival (jacket for 2 wk postarrival), weight (jacket for a minimum of 2 wk and until 65 kg live weight), and wean (jacket until 5 d postweaning). Ambient conditions differed significantly (P < 0.001) during each of the five batches; batch 4 was the coldest with a mean ambient temperature of 6.16 °C. Significant differences were observed between the five batches for day 50 weight (P < 0.01) and disease incidence (P < 0.05). However, treatment had no significant effect on calf health or performance (P > 0.05) during any of the five batches. Skin temperature was significantly greater (P < 0.001) for calves wearing a jacket. Furthermore, there was a significant (P < 0.001) relationship between ambient temperature-humidity index and skin temperature for calves with and without a calf jacket. Therefore, although calf jackets had no benefit in terms of health or performance, they did act as a barrier to environmental conditions.

scholarly journals The Supraclavicular Skin Temperature Response to Mild Cold Stimulation is Dependent on Ambient Temperature

2019 ◽  
pp. 1-5
Author(s):  
Michael E. Symonds ◽  
Helen Budge ◽  
I A Macdonald ◽  
Lindsay Jane Robinson
Keyword(s):  
Ambient Temperature ◽  
Skin Temperature ◽  
Cold Exposure ◽  
Temperature Response ◽  
Ambient Conditions ◽  
Wireless Data ◽  
Cold Stimulation ◽  
Ambient Temperatures ◽  
Brown Adipose ◽  
Supraclavicular Skin Temperature

Purpose: This study investigated the basal activity, and cold-induced thermogenic response, of supraclavicular brown adipose tissue (BAT) under warm (23˚C) and cool (18˚C) ambient conditions using supraclavicular skin temperature as a measure of BAT activity. As a highly metabolic, heat-producing tissue, it has been hypothesised that under-active/dysfunctional BAT may underlie a pathological energy imbalance leading to obesity. Methods: Five lean, healthy participants underwent infrared thermography (IRT) of supraclavicular BAT before, and during, mild cold exposure (single-hand immersion in cool water at 20˚C), once at 18˚C and once at 23˚C. Energy expenditure (EE) was measured simultaneously using indirect calorimetry, and mean skin temperature (TMSK) was calculated at 1-minute intervals in parallel to IRT using wireless data loggers. Results: Following 30 minutes of hand cooling, supraclavicular skin temperature (TSCR) rose significantly from baseline at an ambient temperature of 23˚C (∆TSCR: 0.17 ± 0.03˚C, P < 0.01), and EE rose by 0.22 ± 0.02 kJ/min, P < 0.001. At an ambient room temperature of 18˚C, TSCR after hand cooling was similar to baseline, and EE remained unchanged. The TMSK response was indicative of a systemic vasoconstrictive response of similar magnitude in both warm and cool ambient temperatures. Conclusions: At 18˚C in light clothing, BAT may already be maximally stimulated at baseline, and respond minimally to additional cold exposure. Ambient temperature is recognised as a determinant of glucose uptake in BAT. In this study, we show, that it also modulates the TSCR response to further localised cold-stimulation, indicating an effect on BAT thermogenesis.

Toe Temperatures During Dartmoor Training

1988 ◽  
Vol 74 (3) ◽  
pp. 181-186
Author(s):  
S. P. L. Travis
Keyword(s):  
Surface Temperature ◽  
Ambient Temperature ◽  
Skin Temperature ◽  
Air Temperature ◽  
Factors Associated ◽  
Recording Period ◽  
Exposure To Cold ◽  
Main Factors ◽  
Minimum Air Temperature

AbstractThe surface temperature of eight Royal Marine recruits was monitored in the field during Autumn training on Dartmoor (minimum air temperature 4.5°C). The lowest skin temperature recorded was 6.1°C. One subject experienced a toe temperature below 10° for 5.5 hours and below 15°C for 12.6 hours during a 24 hour recording period. Ambient temperature and inactivity during exposure to cold were the main factors associated with low toe temperatures but individual responses varied widely.

Application of Low Temperature Phase Change Materials to Enable the Cold Weather Operability of B100 Biodiesel in Diesel Trucks

2018 ◽  
Author(s):  
Obiajulu Nnaemeka ◽  
Eric Bibeau
Keyword(s):  
Ambient Temperature ◽  
Phase Change ◽  
Cloud Point ◽  
Canola Oil ◽  
Phase Change Materials ◽  
Fuel Tank ◽  
Cold Weather ◽  
Test Fluid ◽  
Transient Temperature ◽  
Temperature Phase

The use of pure biodiesel for compression ignition engines during the winter poses a challenge due to gelling and plugging of engine filters and fuel lines. The most common method to prevent this issue is blending with petroleum diesel and many engine manufacturers limit the biodiesel in blends to 20% or less for warrantee purposes; as low as 5% may be set for winter months. In a previous work, the authors proposed a novel fuel tank design that could potentially solve this problem and presented a numerical validation of the concept of using phase change materials (PCM) to enable cold weather operability of 100% biodiesel by maintaining its temperature above a cloud point of 5 degrees Celsius for over 3 days at an ambient temperature of −25 degrees Celsius and initial temperature of 20 degrees Celsius. In this research, an experimental analysis is performed using a scaled model of the fuel tank with canola oil as a test fluid in the tank. The tank is subjected to an ambient temperature of −20 degrees Celsius in an icing tunnel facility with air velocity at 10 m/s. The results show that the time above cloud point was increased from 18.6 hours to 22.5 and 33 hours respectively when 4 and 12 PCM tubes were inserted in the tank containing 33 litres of canola oil. A simple numerical model was formulated to predict the transient temperature of the oil and comparison with experimental results showed excellent agreement.

scholarly journals Modeling Indoor Relative Humidity and Wood Moisture Content as a Proxy for Wooden Home Fire Risk

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 5050 ◽  
Author(s):  
Torgrim Log
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Moisture Sorption ◽  
Fire Risk ◽  
Cold Weather ◽  
Indoor Climate ◽  
Ambient Conditions ◽  
Wood Panel ◽  
Fire Disaster ◽  
Strong Winds

Severe wooden home conflagrations have previously been linked to the combination of very dry indoor climate in inhabited buildings during winter time, resulting in rapid fire development and strong winds spreading the fire to neighboring structures. Knowledge about how ambient conditions increase the fire risk associated with dry indoor conditions is, however, lacking. In the present work, the moisture content of indoor wooden home wall panels was modeled based on ambient temperature and relative humidity recorded at meteorological stations as the climatic boundary conditions. The model comprises an air change rate based on ambient and indoor (22 °C) temperatures, indoor moisture sources and wood panel moisture sorption processes; it was tested on four selected homes in Norway during the winter of 2015/2016. The results were compared to values recorded by indoor relative humidity sensors in the homes, which ranged from naturally ventilated early 1900s homes to a modern home with balanced ventilation. The modeled indoor relative humidity levels during cold weather agreed well with recorded values to within 3% relative humidity (RH) root mean square deviation, and thus provided reliable information about expected wood panel moisture content. This information was used to assess historic single home fire risk represented by an estimated time to flashover during the studied period. Based on the modelling, it can be concluded that three days in Haugesund, Norway, in January 2016 were associated with very high conflagration risk due to dry indoor wooden materials and strong winds. In the future, the presented methodology may possibly be based on weather forecasts to predict increased conflagration risk a few days ahead. This could then enable proactive emergency responses for improved fire disaster risk management.

Studies on the adaptability of three breeds of sheep to a tropical environment modified by altitude II. Responses in body, skin and coat temperatures, cardio-respiratory frequencies and rate of moisture secretion of ewes to the diurnal fluctuation in ambient temperature during the hottest part of the year

1960 ◽  
Vol 55 (3) ◽  
pp. 295-302 ◽  
Author(s):  
R. B. Symington
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Skin Temperature ◽  
Skin Surface ◽  
Diurnal Fluctuation ◽  
Body Temperatures ◽  
Solar Insolation ◽  
Air Temperatures ◽  
Insensible Perspiration ◽  
Artificial Heat

Responses in body, skin and coat temperatures, cardio-respiratory frequencies and rate of moisture secretion of ewes of three breeds to the diurnal fluctuation in ambient temperature were recorded in the presence and absence of drinking water during the hottest part of the Rhodesian year.1. At 7.0 a.m. body temperatures were: Merino 102·8° F.; Persian 102·2° F. and Native 101·5° F. Between 7·0 a.m. and 1·0 p.m. body temperature rose almost equally in Persians and Natives and fell slightly in Merinos. Change in body temperature between 7.0 a.m. and 1.0 p.m. was not affected significantly by availability of water nor age of ewe, but varied with type of thermal burden (i.e. solar insolation only v. solar insolation plus artificial heat) when water was not available. Although air temperature fell towards late afternoon body temperature of Merinos and Natives rose appreciably, that of Persians only slightly.2. At 7·0 a.m. respiratory rates were (cyc./min.): Merino 59·6; Persian 43·0; Native 29·9. Increase in rate of respiration was the main thermolytic mechanism in all breeds. Merinos had a lower threshold of respiratory response to rising ambient temperature than either hair breed but increase in rate of respiration between 7.0 a.m. and 1.0 p.m. did not differ significantly with breed or age.3. No breed appeared to use the peripheral blood system in thermoregulation. Cardio-frequency, as a measure of this blood flow, remained almost constant with a slight tendency to fall with rise in ambient temperature.4. In all breeds skin temperature was related to ambient and body temperatures; consequently the diurnal fluctuation in skin temperature differed in wool and hair breeds. When thermal burden was greatest Merino skin temperature fell, that of hair breeds did not.Except at 11.0 a.m. there was a gradient between rectal, skin and air temperatures. Direct elimination of heat was thus possible for 23 hr. each day.5. In hair breeds moisture secretion depended on insensible perspiration; consequently, rate of moisture secretion changed with body and air temperatures. In Merinos moisture for skin surface evaporation was provided by sensible and insensible perspiration. Natives may be able to sweat at temperatures higher than those recorded but it is unlikely Persians have a sweating mechanism.6. In all breeds coat temperature was related closely to ambient temperature and changes in solar conditions evoked immediate response in coat temperature. Merino fleece apparently stabilized skin temperature whereas Persian and Native hair did not.

Physiology of Oil Seeds. X. Seed Quality of Peanut Genotypes as Affected by Ambient Storage Temperature1

1992 ◽  
Vol 19 (2) ◽  
pp. 72-77 ◽  
Author(s):  
Darold L. Ketring
Keyword(s):  
Ambient Temperature ◽  
Seedling Growth ◽  
Seed Quality ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Ambient Conditions ◽  
Ambient Storage ◽  
Wide Range ◽  
Genotype Diversity ◽  
Field Emergence

Abstract Proper storage of peanut (Arachis hypogaea L.) pods following drying is a critical step in maintenance of seed quality for the next planting season. The objective of this study was to examine the effect of ambient storage temperature (similar to farmers stock peanuts stored in warehouses) on seed germination and seedling vigor of selected peanut genotypes. Peanuts were grown in the field for three successive seasons. Pods were harvested, dried, and shelled. Seed samples were taken for storage under ambient conditions, humidity effects were eliminated by storing the seeds in plastic freezer bags in sealed containers. Seasons were: (1) 1986, 19 months storage at ambient temperature, (2) 1987, 7 months storage at ambient temperature, and (3) 1988, seeds without storage. When comparisons were made among genotypes within seasons, exposure to Season 1 conditions resulted in the least germination and seedling growth, but a wide range of genotype diversity occurred. Germination of seeds from Seasons 2 and 3 ranged from 81 to 98%, and significant differences in seedling growth occurred among genotypes. When comparisons were made across Seasons, the data indicated a significant storage effect, which resulted in different seed quality for individual genotypes. Usually field emergence was significantly different among genotypes and was highly correlated with germination for all seasons. Generally, emergence was negatively correlated with slow seedling growth and positively correlated with rapid seedling growth. Thus, for seeds of lower vigor (Seasons 1 and 2), rapid seedling growth was particularly critical for early, uniform emergence (10 DAP) in the field. Genotypes were significantly different in extent of seed quality reduction and field emergence both within and across storage periods. Genotype diversity to ambient storage conditions suggests there is genetic potential to improve longevity of seed quality during storage and enhance stability of field emergence.

Design of Solar Assisted Community Biogas Plant

2009 ◽  
Author(s):  
Ankit Gupta
Keyword(s):  
Anaerobic Fermentation ◽  
Weather Conditions ◽  
Biogas Plant ◽  
Heat Transfer Fluid ◽  
Cold Weather ◽  
Ambient Conditions ◽  
Biogas Yield ◽  
Northern India ◽  
Collector System ◽  
Sufficient Energy

This study aims at providing a solution to the difficulty in the production of biogas in cold weather conditions especially during winters and in hilly regions where the temperature remains low throughout the year. As is well known biogas can be produced by anaerobic fermentation of organic materials with the help of bacteria [1]. Meynell [2] pointed out that the production of biogas becomes insignificant when the slurry temperature is less than 15°C. Such situations are usually faced in northern India, where the ambient temperature and, hence, the slurry temperature, in the winters drops below 15°C and hence improper digestion of slurry leads to poor biogas yield. This problem can be overcome by making the biogas plant solar assisted. The heat requirements of the digesters generally consist of three parts; (i) heat required for raising the temperature of incoming slurry for digestion; (ii) for compensating heat losses through the boundaries of the digester and (iii) for compensating losses that might occur in the piping between the heat source and the digester [3]. The required heat is provided from the collector which absorbs solar radiation and converts it into heat which is absorbed by a heat transfer fluid passing through the collector [4]. In this work, a biogas plant for a specified capacity has been designed. Based on the biogas plant dimensions and the average ambient conditions for a specified location, the rate of loss of energy was determined. A solar collector system has been designed to supply sufficient energy to maintain the slurry temperature of 35° C.

Measurement of the work function of Y1Ba2Cu3O7−δ under ambient conditions

1993 ◽  
Vol 8 (7) ◽  
pp. 1497-1500 ◽  
Author(s):  
Jon DeVries ◽  
Steve S. Wakisaka ◽  
Erik R. Spjut
Keyword(s):  
Standard Deviation ◽  
Ambient Temperature ◽  
Work Function ◽  
Ambient Conditions ◽  
Minimum Value ◽  
Electrodynamic Balance

The photoelectric work function of samples of Y1Ba2Cu3O7−δ of approximately 40 μm diameter was measured under ambient temperature and atmosphere in an electrodynamic balance. The measured values had an average of 4.98 eV and a standard deviation of 0.24 eV. The minimum value was 4.46 eV and the maximum was 5.52 eV.

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