scholarly journals Why Physiologically Cold weather can Increase Obesity Rates?

2018 ◽  
Vol 2 (1) ◽  
pp. 11-13
Author(s):  
Nasim Habibzadeh
Keyword(s):  
Ambient Temperature ◽  
Cold Temperature ◽  
Cold Weather ◽  
Cold Environment ◽  
Body Parts

Obesity generally accounts for a pathophysiology condition at which excessive body fats get accumulated in body parts. Among different - causes, ambient temperature such as cold environment can dramatically develop obesity in different individual. Cold weather influences the hormones that are related to the hunger and increases appetite toward overeating and subsequently inactivity . Controlling the calorie intakes through informative care are good strategies to prevent or govern obesity at any situation such as cold temperature

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.

Analysis of energy expenditure at different ambient temperatures in mice lacking DGAT1

2003 ◽  
Vol 284 (1) ◽  
pp. E213-E218 ◽  
Author(s):  
Hubert C. Chen ◽  
Zuleika Ladha ◽  
Steven J. Smith ◽  
Robert V. Farese
Keyword(s):  
Food Intake ◽  
Energy Expenditure ◽  
Ambient Temperature ◽  
Cold Environment ◽  
Normal Surface ◽  
Ambient Temperatures ◽  
Active Mechanism ◽  
Key Enzyme ◽  
Secondary Mechanism ◽  
Obesity Resistance

Mice lacking acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1), a key enzyme in triglyceride synthesis, have increased energy expenditure and therefore are resistant to obesity. Because ambient temperature can significantly affect energy expenditure in mice, we undertook these studies to determine the effects of different ambient temperatures on energy expenditure, food intake, and thermoregulation in DGAT1-deficient [ Dgat1(−/−)] mice. Dgat1(−/−) mice had increased energy expenditure irrespective of changes in the ambient temperature. Although core temperature was normal, surface temperature was increased in Dgat1(−/−) mice, most likely reflecting an active mechanism to dissipate heat from increased thermogenesis. Dgat1(−/−) mice had increased food intake at baseline, and this hyperphagia became more pronounced upon exposure to cold. When fasted in a cold environment, Dgat1(−/−) mice developed hypothermia, which was associated with hypoglycemia. These results suggest that the hyperphagia in Dgat1(−/−) mice is a secondary mechanism that compensates for the increased utilization of fuel substrates. Our findings offer insights into the mechanisms of hyperphagia and increased energy expenditure in a murine model of obesity resistance.

scholarly journals Effect of Temperature on the Size of Sedimentary Remains of Littoral Chydorids

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1309
Author(s):  
János L. Korponai ◽  
Csilla Kövér ◽  
Charo López-Blanco ◽  
István Gyulai ◽  
László Forró ◽  
...  
Keyword(s):  
Body Size ◽  
Ambient Temperature ◽  
Lacustrine Sediments ◽  
The Body ◽  
Effect Of Temperature ◽  
Body Parts ◽  
Morphological Response ◽  
Subfossil Remains ◽  
Different Response ◽  
Increasing Temperature

The body size of aquatic invertebrates is, to a great extent, dependent on ambient temperature, but size distributions are also determined by other factors like food supply and predation. The effect of temperature on organisms is formulated in the temperature–size hypothesis, which predicts a smaller body size with increasing temperature. In this study, the effect of temperature on the subfossil remains of three littoral Cladocera (Alona affnis, A. quadrangularis, and Chydorus cf. sphaericus) was investigated. Exoskeletal remains of these species can be found in large numbers in lacustrine sediments and over a wide north–south range in Europe. The total length of both headshield and postabdomen for A. affinis and A. quadrangularis and carapace length for C. cf. sphaericus were measured to observe their response to changes in latitude and temperature. A different response to ambient temperature in the growth of body parts was observed. The size of the headshields of both Alona species and of the carapace of Chydorus was significantly larger in colder regions as opposed to warm ones. It turned out that the postabdomen was not a good predictor of ambient temperature. While the sizes of all remains increased with latitude, the sizes of the Alona remains was smaller in the mountain lakes of the Southern Carpathians than in other cold lakes, in this case in Finland, a fact indicative of the importance of other factors on size distribution. This study demonstrates that a morphological response to climate is present in littoral cladocerans, and, therefore, changes in the length of headshield and carapace may be used as a proxy for climate changes in paleolimnological records.

scholarly journals The Impact of Non-optimum Ambient Temperature on Years of Life Lost: A Multi-county Observational Study in Hunan, China

2020 ◽  
Vol 17 (8) ◽  
pp. 2699
Author(s):  
Ling-Shuang Lv ◽  
Dong-Hui Jin ◽  
Wen-Jun Ma ◽  
Tao Liu ◽  
Yi-Qing Xu ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Ambient Temperature ◽  
Respiratory Disease ◽  
Age Groups ◽  
The Elderly ◽  
Cold Temperature ◽  
Years Of Life Lost ◽  
Distributed Lag ◽  
Preventative Measures ◽  
The Impact

The ambient temperature–health relationship is of growing interest as the climate changes. Previous studies have examined the association between ambient temperature and mortality or morbidity, however, there is little literature available on the ambient temperature effects on year of life lost (YLL). Thus, we aimed to quantify the YLL attributable to non-optimum ambient temperature. We obtained data from 1 January 2013 to 31 December 2017 of 70 counties in Hunan, China. In order to combine the effects of each county, we used YLL rate as a health outcome indicator. The YLL rate was equal to the total YLL divided by the population of each county, and multiplied by 100,000. We estimated the associations between ambient temperature and YLL with a distributed lag non-linear model (DNLM) in a single county, and then pooled them in a multivariate meta-regression. The daily mean YLL rates were 22.62 y/(p·100,000), 10.14 y/(p·100,000) and 2.33 y/(p·100,000) within the study period for non-accidental, cardiovascular, and respiratory disease death. Ambient temperature was responsible for advancing a substantial fraction of YLL, with attributable fractions of 10.73% (4.36–17.09%) and 16.44% (9.09–23.79%) for non-accidental and cardiovascular disease death, respectively. However, the ambient temperature effect was not significantly for respiratory disease death, corresponding to 5.47% (−2.65–13.60%). Most of the YLL burden was caused by a cold temperature than the optimum temperature, with an overall estimate of 10.27% (4.52–16.03%) and 15.94% (8.82–23.05%) for non-accidental and cardiovascular disease death, respectively. Cold and heat temperature-related YLLs were higher in the elderly and females than the young and males. Extreme cold temperature had an effect on all age groups in different kinds of disease-caused death. This study highlights that general preventative measures could be important for moderate temperatures, whereas quick and effective measures should be provided for extreme temperatures.

scholarly journals A Case of Special Complication following a Large Amount of Polyacrylamide Hydrogel Injected into the Epicranial Aponeurosis: Leukocytopenia

2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
Li Rong ◽  
Shi-Jie Lan ◽  
Ying Shao ◽  
Zhe Chen ◽  
Duo Zhang
Keyword(s):  
Soft Tissue ◽  
Facial Expression ◽  
Ambient Temperature ◽  
Female Patient ◽  
Blood Supply ◽  
Soft Tissue Augmentation ◽  
Body Parts ◽  
Polyacrylamide Hydrogel ◽  
The Face ◽  
Injectable Filler

Polyacrylamide hydrogel (PAAG) has been used as an injectable filler for soft tissue augmentation of different body parts, such as the face, breasts, and penis. However, this is the first report of leukocytopenia after injection of a large amount of PAAG in the epicranial aponeurosis. After receiving PAAG injection for craniofacial contouring, the female patient described herein experienced recurrent swelling, temporal pain (particularly with changes in ambient temperature and facial expression), and ultimately leukocytopenia due to widespread migration of the injected PAAG. We removed most of the PAAG from the affected tissues and the leukocytopenia disappeared 1 year after the operation. Based on this case, we hypothesize that injection of a large amount of PAAG into tissues that have ample blood supply, such as the epicranial aponeurosis, may induce leukocytopenia.

Selected Contribution: Ambient temperature for experiments in rats: a new method for determining the zone of thermal neutrality

2002 ◽  
Vol 92 (6) ◽  
pp. 2667-2679 ◽  
Author(s):  
Andrej A. Romanovsky ◽  
Andrei I. Ivanov ◽  
Yury P. Shimansky
Keyword(s):  
Ambient Temperature ◽  
Body Core Temperature ◽  
Body Parts ◽  
Experimental Conditions ◽  
Strong Negative Correlation ◽  
Liquid Crystal Thermography ◽  
Body Core ◽  
Definition Of ◽  
Operational Range ◽  
Rat Tail

There is a misbelief that the same animal has the same thermoneutral zone (TNZ) in different experimental setups. In reality, TNZ strongly depends on the physical environment and varies widely across setups. Current methods for determining TNZ require elaborate equipment and can be applied only to a limited set of experimental conditions. A new, broadly applicable approach that rapidly determines whether given conditions are neutral for a given animal is needed. Consistent with the definition of TNZ [the range of ambient temperature (Ta) at which body core temperature (Tc) regulation is achieved only by control of sensible heat loss], we propose three criteria of thermoneutrality: 1) the presence of high-magnitude fluctuations in skin temperature (Tsk) of body parts serving as specialized heat exchangers with the environment (e.g., rat tail), 2) the closeness of Tsk to the median of its operational range, and 3) a strong negative correlation between Tskand Tc. Thermocouple thermometry and liquid crystal thermography were performed in five rat strains at 13 Ta. Under the conditions tested (no bedding or filter tops, no group thermoregulation), the Ta range of 29.5–30.5°C satisfied all three TNZ criteria in Wistar, BDIX, Long-Evans, and Zucker lean rats; Zucker fatty rats had a slightly lower TNZ (28.0–29.0°C). Skin thermometry or thermography is a definition-based, simple, and inexpensive technique to determine whether experimental or housing conditions are neutral, subneutral, or supraneutral for a given animal.

Inhibition of shivering during restraint hypothermia

1983 ◽  
Vol 61 (9) ◽  
pp. 977-982 ◽  
Author(s):  
Steven G. Shimada ◽  
John T. Stitt
Keyword(s):  
Metabolic Rate ◽  
Ambient Temperature ◽  
Cold Environment ◽  
Conscious Rats ◽  
Threatening Situation ◽  
Skin Temperatures ◽  
Shivering Thermogenesis ◽  
Cold Restraint

Restraint hypothermia has often been described, but its cause has never been clarified. We hypothesized that it might be due to a suppression of shivering thermogenesis. Thus, we restrained conscious rats in an ambient temperature of 2 °C while measuring rectal (Tre) and tail skin temperatures, metabolic rate (MR), and shivering activity. When rats were cold exposed but not restrained, Tre fell 1.4 ± 0.2 °C (SE) during the 1st h. When these same rats were restrained, Tre fell at a rate of 6.5 ± 0.2 °C/h. MR averaged 15.7 ± 1.4 W/kg for the unrestrained rats, but it averaged only 9.0 ± 1.1 W/kg for the restrained rats. The restrained rats showed no signs of shivering. The animals were then subjected to a restraint adaptation regimen and then reexposed to cold. Restraint now produced a fall in Tre of only 2.6 ± 0.7° C/h. The animals shivered and generated an MR of 15.8 ± 0.9 W/kg. Naive rats became hypothermic because restraint suppressed shivering activity. However, adapted rats continued to shiver and remained normothermic. We suggest that a stressful or threatening situation, such as restraint for a naive rat, inhibits shivering and leads to hypothermia in a cold environment. This would not occur in adapted rats because restraint is no longer stressful.

scholarly journals Hunting strategies by Siberian Jays Perisoreus infaustus on wintering small rodents

2016 ◽  
Vol 39 ◽  
pp. 25
Author(s):  
Olav Hogstad
Keyword(s):  
Ambient Temperature ◽  
Mixed Forest ◽  
Cold Weather ◽  
Myodes Glareolus ◽  
Snow Surface ◽  
Small Rodents ◽  
Hunting Strategies ◽  
Bank Voles ◽  
Perisoreus Infaustus ◽  
Rodent Abundance

The Siberian Jay Perisoreus infaustus, the smallest of west Palearctic corvids, is year-round resident, territorial and stores food prior to the winter. I studied the species’ hunting strategies on small rodents from November through March during 2004–2015 in a subalpine mixed forest in central Norway. Along a fixed track of ca. 5 km, I recorded where a flock of Siberian Jays was first observed. In years when small rodents (mainly bank voles Myodes glareolus) were abundant, the birds were most often seen in trees near open areas with numerous tracks of rodents, and mainly within the forest in years with low rodent abundance. In cold days, i.e. with ambient temperature below –10 oC, very few tracks of small rodents were registered in the snow despite high rodent abundance, and the birds then stayed within the forest. Siberian Jays apparently often stay near open areas hunting for small rodents running in the snow in years with a high rodent abundance, but keep more within the forest in years with low rodent abundance or in cold weather when the rodents live below the snow surface.

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