Search

Temporally variable climates are expected to drive the evolution of thermal physiological traits that enable performance across a wider range of temperatures (i.e. climate variability hypothesis, CVH). Spatial thermal variability, however, may mediate this relationship by providing ectotherms with the opportunity to behaviourally select preferred temperatures (i.e. the Bogert effect). These antagonistic forces on thermal physiological traits may explain the mixed support for the CVH within species despite strong support among species at larger geographical scales. Here, we test the CVH as it relates to plasticity in physiological upper thermal limits (critical thermal maximum—CTmax) among populations of coastal tailed frogs (Ascaphus truei). We targeted populations that inhabit spatially homogeneous environments, reducing the potentially confounding effects of behavioural thermoregulation. We found that populations experiencing greater temporal thermal variability exhibited greater plasticity in CTmax, supporting the CVH. Interestingly, we identified only one site with spatial temperature variability and tadpoles from this site demonstrated greater plasticity than expected, suggesting the opportunity for behavioural thermoregulation can reduce support for the CVH. Overall, our results demonstrate one role of climate variability in shaping thermal plasticity among populations and provide a baseline understanding of the impact of the CVH in spatially homogeneous thermal landscapes. [ABSTRACT FROM AUTHOR]

Local adaptation is key for ecotypic differentiation and species evolution. Understanding underlying genomic patterns can allow the prediction of future maladaptation and ecosystem stability. Here, we report the whole-genome resequencing of 874 individuals from 100 range-wide populations of European beech (Fagus sylvatica L.), an important forest tree species in Europe. We show that genetic variation closely mirrors geography with a clear pattern of isolation-by-distance. Genome-wide analyses for genotype-environment associations (GEAs) identify relatively few potentially adaptive variants after correcting for an overwhelming signal of statistically significant but non-causal GEAs. We characterize the single high confidence genomic region and pinpoint a candidate gene possibly involved in winter temperature adaptation via modulation of spring phenology. Surprisingly, allelic variation at this locus does not result in any apparent fitness differences in a common garden. More generally, reciprocal transplant experiments across large climate distances suggest extensive phenotypic plasticity. Nevertheless, we find indications of polygenic adaptation which may be essential in natural ecosystems. This polygenic signal exhibits broad- and fine-scale variation across the landscape, highlighting the relevance of spatial resolution. In summary, our results emphasize the importance, but also exemplify the complexity, of employing natural genetic variation for forest conservation under climate change. The genomic basis of local adaptation can contribute to predicting species' future maladaptation. This study shows that local adaptation in European beech is genetically complex, with current analyses only skimming the surface of the encoded information, highlighting the need for bigger data. [ABSTRACT FROM AUTHOR]

A spontaneously occurring temperature increase in solid tumors has been reported sporadically, but is largely overlooked in terms of cancer biology. Here we show that temperature is increased in tumors of patients with pancreatic ductal adenocarcinoma (PDAC) and explore how this could affect therapy response. By mimicking this observation in PDAC cell lines, we demonstrate that through adaptive changes in lipid metabolism, the temperature increase found in human PDAC confers protection to lipid peroxidation and contributes to gemcitabine resistance. Consistent with the recently uncovered role of p38 MAPK in ferroptotic cell death, we find that the reduction in lipid peroxidation potential following adaptation to tumoral temperature allows for p38 MAPK inhibition, conferring chemoresistance. As an increase in tumoral temperature is observed in several other tumor types, our findings warrant taking tumoral temperature into account in subsequent studies related to ferroptosis and therapy resistance. More broadly, our findings indicate that tumoral temperature affects cancer biology. The development of cancer is typically accompanied by changes in the tumor microenvironment that support tumor growth and affect therapy response. Here, the authors show that increased intratumoral temperature is an inherent feature of human pancreatic cancer and contributes to therapy resistance by altering the lipid content of the tumor. [ABSTRACT FROM AUTHOR]

Collagen possesses distinctive chemical properties and biological functions due to its unique triple helix structure. However, recombinant collagen expressed in Escherichia coli without post-translational modifications such as hydroxylation lacks full function since hydroxylation is considered to be critical to the stability of the collagen triple-helix at body temperature. Here, a proline-deficient E. coli strain was constructed and employed to prepare hydroxylated recombinant collagens by incorporating proline (Pro) and hydroxyproline (Hyp) from the culture medium. By controlling the ratio of Pro to Hyp in the culture medium, collagen with different degrees of hydroxylation (0–88%) can be obtained. When the ratio of Pro and Hyp was adjusted to 12:8 mM, the proline hydroxylation rate of recombinant human collagen (rhCol, 55 kDa) ranged from 40–50%, which was also the degree of natural collagen. After proline hydroxylation, both the thermal stability and cell binding of rhCol were significantly enhanced. Notably, when the hydroxylation rate approached that of native human collagen (40–50%), the improvements were most pronounced. Moreover, the cell binding of rhCol with a hydroxylation rate of 43% increased by 29%, and the melting temperature (Tm) rose by 5 °C compared to the non-hydroxylated rhCol. The system achieved a yield of 1.186 g/L of rhCol by batch-fed in a 7 L fermenter. This innovative technology is expected to drive the development and application of collagen-related biomaterials with significant application value in the fields of tissue engineering, regenerative medicine, and biopharmaceuticals. [ABSTRACT FROM AUTHOR]

Foraminifera is the most important temperature proxy of the ocean on long time scales. However, the absence of temperature‐controlled experiments at different water depths hinders the advancement of paleotemperature reconstruction with foraminifera from the continental shelf. For the first time, this study investigated the response of benthic foraminifera to temperature change using microcosm culture and metabarcoding. Foraminiferal communities from three continental stations at varying water depths (6.0, 9.2, and 26.0 m) were cultured under five temperature gradients (6, 12, 18, 24, and 30°C), with each treatment performed in triplicate. The foraminifera were fed with microalgae every 4 days, and the filtered seawater (through 0.22 μm pores), acting as a medium, was changed accordingly. The experiment lasted for 80 days, and 47 DNA samples were obtained and analyzed, including three in situ samples. The results showed that foraminifera adjusted its growth rate within the low‐temperature range and adopted an r‐strategy to cope with high‐temperature stress. In addition, the foraminifera from deeper water stations exhibited a pronounced vulnerability to diminishing read counts. The read counts, operational taxonomic units (OTU) counts and Margalef index of foraminifera and the read counts of Rotaliida exhibited a remarkably positive correlation with temperature. The recommended relationships were described as read counts = 1314.75*T + 44754.51; OTU counts = 1.13*T + 44.26; Margalef index =1.13*T + 44.26. This study established the first quantitative relationship between temperature and foraminifera molecular parameters that holds significant implications for long‐time paleotemperature calibration in climate change. [ABSTRACT FROM AUTHOR]

Deschampsia antarctica and Colobantus quitensis are the only two vascular plants colonized on the Antarctic continent, which is usually exposed to extreme environments. Endophytic bacteria residing within plant tissues can exhibit diverse adaptations that contribute to their ecological success and potential benefits for their plant hosts. This study aimed to characterize 12 endophytic bacterial strains isolated from these plants, focusing on their ecological adaptations and functional roles like plant growth promotion, antifungal activities, tolerance to salt and low-carbon environments, wide temperature range, and biofilm formation. Using 16S rRNA sequencing, we identified several strains, including novel species like Hafnia and Agreia. Many strains exhibited nitrogen-fixing ability, phosphate solubilization, ammonia, and IAA production, potentially benefiting their hosts. Additionally, halotolerance and carbon oligotrophy were also shown by studied bacteria. While some Antarctic bacteria remain strictly psychrophilic, others demonstrate a remarkable ability to tolerate a wider range of temperatures, suggesting that they have acquired mechanisms to cope with fluctuations in environmental temperature and developed adaptations to survive in intermediate hosts like mammals and/or birds. Such adaptations and high plasticity of metabolism of Antarctic endophytic bacteria provide a foundation for research and development of new promising products or mechanisms for use in agriculture and technology. [ABSTRACT FROM AUTHOR]

Tomato plants favor warmth, making them particularly susceptible to cold conditions, especially their reproductive development. Therefore, understanding how pollen reacts to cold stress is vital for selecting and improving cold-resistant tomato varieties. The programmed cell death (PCD) in the tapetum is particularly susceptible to cold temperatures which could hinder the degradation of the tapetal layer in the anthers, thus affecting pollen development. However, it is not clear yet how genes integral to tapetal degradation respond to cold stress. Here, we report that SlHB8, working upstream of the conserved genetic module DYT1-TDF1-AMS-MYB80, is crucial for regulating cold tolerance in tomato anthers. SlHB8 expression increases in the tapetum when exposed to low temperatures. CRISPR/Cas9-generated SlHB8-knockout mutants exhibit improved pollen cold tolerance due to the reduced temperature sensitivity of the tapetum. SlHB8 directly upregulates SlDYT1 and SlMYB80 by binding to their promoters. In normal anthers, cold treatment boosts SlHB8 levels, which then elevates the expression of genes like SlDYT1, SlTDF1, SlAMS, and SlMYB80; however, slhb8 mutants do not show this gene activation during cold stress, leading to a complete blockage of delayed tapetal programmed cell death (PCD). Furthermore, we found that SlHB8 can interact with both SlTDF1 and SlMYB80, suggesting the possibility that SlHB8 might regulate tapetal PCD at the protein level. This study sheds light on molecular mechanisms of anther adaptation to temperature fluctuations. [ABSTRACT FROM AUTHOR]

In humans and many animals, a trade-off between a sufficiently high concentration of erythrocytes (hematocrit) to bind oxygen and sufficiently low blood viscosity to allow rapid blood flow has been achieved during evolution. The optimal value lies between the extreme cases of pure blood plasma, which cannot practically transport any oxygen, and 100% hematocrit, which would imply very slow blood flow or none at all. As oxygen delivery to tissues is the main task of the cardiovascular system, it is reasonable to expect that maximum oxygen delivery has been achieved during evolution. Optimal hematocrit theory, based on this optimality principle, has been successful in predicting hematocrit values of about 0.3–0.5, which are indeed observed in the systemic circulation of humans and many animal species. Similarly, the theory can explain why a hematocrit higher than normal, ranging from 0.5 to 0.7, can promote better exertional performance. Here, we present a review of theoretical approaches to the calculation of the optimal hematocrit value under different conditions and discuss them in a broad physiological context. Several physiological and medical implications are outlined, for example, in view of blood doping, temperature adaptation, dehydration, and life at high altitudes. [ABSTRACT FROM AUTHOR]

Endoscopy patients often face an uncertain, cold, anxious and thirsty wait for their procedure. Managing patient temperature is not a central concern of endoscopy nurses, whose attention and efforts are drawn to multiple other priorities. However, inadvertent hypothermia, defined as a non-intentional loss of body heat resulting in core temperature less than 36 degrees, increases morbidity, mortality and psychological distress in surgical patients. Little is known about the impact of inadvertent peri-procedural hypothermia during endoscopy procedures, however, there is potential for similar negative impacts on mental and physical health. Further, traditional practice norms mean that warmed cotton blankets remain the primary source of temperature management in many endoscopy units, despite evidence showing they are ineffective in increasing or maintaining patient's core temperature. Endoscopy patient outcomes and experiences could be improved by managing core temperature. Endoscopy nurses can take simple, evidence-based actions to support patients to maintain core temperature, resulting in a more comfortable procedural experience. Potential actions include increasing ambient temperatures in waiting and procedural areas, monitoring temperature, encouraging patients to speak up if cold, providing dressing gowns or encouraging patients to bring and wear personal warm clothing pre and post-procedure, initiating active warming if patients are hypothermic, express feelings of cold or are experiencing long wait times, assess for potential long procedures and utilise active peri-procedural warming, minimise body exposure during the procedure and prioritise active warming in the post-sedation recovery period. Whilst changing practice may have financial and environmental costs, a shift away from ineffective warmed cotton blankets will minimise the climate impacts associated with cloth blankets whilst improving patient comfort and potentially physical and psychological health. [ABSTRACT FROM AUTHOR]

Thermomyces dupontii harbors two P450 paralogs (P450S and P450L) in the gene cluster for the biosynthesis of prenylated indole alkaloids (PIAs) and correponding iron chelators with P450L assigned as one protein containing a CYP like domain fused with a FAD-binding domain-containing oxidoreductase. Genetic manipulation and metabolic profile analysis indicated both P450S and P450L were involved in transforming simple PIAs to their corresponding iron chelators. Moreover, P450S is responsible for bolstering simple PIAs to complex PIAs, and P450L for reinforcing conjugating unsaturated systems in complex PIAs. Chemical investigation led to isolation and characterization of novel complex PIA metabolites with more oxidations. P450L also contributed to forming the third iron-chelating core in iron chelators. A series of iron bioassays and infrastructure analysis revealed that lack of these P450 genes caused strongly elevated Fe3+ levels but attenuated Fe2+ levels, together with abnormal mitochondria in mycelia and lipid droplets and vacuoles in conidia. Phenotype analysis revealed that P450S and P450L facilitated fungal colony pigments, conidial formation and germination via bolstering conidiophores and cell walls in response to temperature reduction. [ABSTRACT FROM AUTHOR]

Many thermal indices have been developed to assess the levels of heat stress imposed on cattle during hot weather. In this paper, the 16 cattle-related thermal indices are critically reviewed. The primary emphasis is to evaluate each index's coherence to the typical heat transfer characteristics of a cow. Other perspectives including incorporated environmental parameters in the equation(s), experimental data, correlated physiological responses, heat-stress thresholds, scope of application, specific cattle breed involved, and experiment location(s) are also well categorised and discussed. The coherence evaluation indicates that the main effects of environmental parameters on heat stress have been properly reflected, while some interactions between the parameters have been treated differently. Given the variety of the equations used to define the 16 indices and the wide range of information used to develop each index, we conclude that each thermal index is distinct to an extent that it should be selected and employed carefully., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The present paper aimed to show the thermoregulatory responses of locally adapted Morada Nova sheep with different coat colors that were exposed to direct solar radiation in an equatorial semiarid region. Animals were classified into four groups according to the coat color as follows: (1) dark red, (2) intermediate red, (3) light red, and (4) white coats. Forty Morada Nova ewes were observed in for 7 consecutive months. The experimental variables measured were rectal temperature (RT), skin surface temperature (ST), respiratory rate (RR), skin surface evaporation (CE), respiratory evaporation (RE), and heat exchange by convection (HC) and radiation (R). Data were collected from 1100 to 1400 h after the animals were exposed to 30 min direct sunlight. The results showed that all groups maintained homeothermy. The R R was higher in the animals of groups 1 to 3, which also showed higher values for ST when compared to the white-coated animals. Sensible heat exchange mechanisms were not important for heat loss, and R was a significant source of heat gain from the environment for the animals. Groups 1, 2, and 3 used RR more intensely than group 4 (P value = 0.001); however, CE was higher for the white-coated animals. It was concluded that Morada Nova sheep are well adapted to the semiarid environment, regardless of coat color.

A role for 5-hydroxytryptamine (5-HT) or serotonin in sleep has been known for decades but was challenged by recent papers that concluded that the apparent sleep phenotype was secondary to defective thermoregulation. Those studies used mice lacking serotonergic neurons resulting from the loss of function mutations in the gene encoding the LIM homeobox transcription factor 1 ( Lmx1b ). Here we show that, while Lmx1b mutants failed to keep the physiologic body temperature, they exhibited more activities at the room and elevated temperatures. More importantly, we used mice deficient in the gene encoding tryptophan hydroxylase 2 ( Tph2 ), which could not synthesize 5-HT in the brain. Tph2 mutants were capable of thermoregulation and keeping physiologic body temperature when the environmental temperature was reduced and exhibited significantly more activities at both the room and elevated temperatures. Electroencephalographic (EEG) recording also showed decreased sleep in Tph2 -deficient mice. Our results indicate that 5-HT is important for sleep regulation but not thermoregulation., (Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.)

This study aims to develop an approach to couple a computational fluid dynamics (CFD) solver to the University of California, Berkeley (UCB) thermal comfort model to accurately evaluate thermal comfort. The coupling was made using an iterative JavaScript to automatically transfer data for each individual segment of the human body back and forth between the CFD solver and the UCB model until reaching convergence defined by a stopping criterion. The location from which data are transferred to the UCB model was determined using a new approach based on the temperature difference between subsequent points on the temperature profile curve in the vicinity of the body surface. This approach was used because the microclimate surrounding the human body differs in thickness depending on the body segment and the surrounding environment. To accurately simulate the thermal environment, the numerical model was validated beforehand using experimental data collected in a climate chamber equipped with a thermal manikin. Furthermore, an example of the practical implementations of this coupling is reported in this paper through radiant floor cooling simulation cases, in which overall and local thermal sensation and comfort were investigated using the coupled UCB model., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

It is common practice in India to consume the dairy drink buttermilk as a way of mitigating occupational heat strain. This paper explores the thermoregulatory and hydration benefits of drinking buttermilk but also the impacts of work in a hot environment on the gut microbiota, renal and cognitive function. Twelve healthy participants were subjected to a 3-h period of medium load physical intermittent work in a climatic chamber (34°C, 60% RH). The subjects were given water, buttermilk (700 ml) or no rehydration at random. Mean body temperatures when no rehydration was given were significantly higher (p≤0.001). When subjects drank water or buttermilk they had a lower sweat rate than with no rehydration (p≤0.05) and the perception of feeling hot, uncomfortable, thirsty and physically exerted was significantly reduced (p≤0.05). A hormonal stress response at the end of the exposure was seen when not drinking (p≤0.05). No differences in cognitive abilities and gut microbiota were found. The exposure lowered the renal blood flow suggesting an acute impact of short term heat exposure. It was also found that buttermilk has a protective effect on this impact. Our results demonstrated that keeping hydrated by water/buttermilk consumption mitigates heat strain in well-nourished subjects.

Objectives: The laboratory mouse is presently the most common model for examining mechanisms of human physiology and disease. Housing temperatures can have a large impact on the outcome of such experiments and on their translatability to the human situation. Humans usually create for themselves a thermoneutral environment without cold stress, while laboratory mice under standard conditions (≈20° C) are under constant cold stress. In a well-cited, theoretical paper by Speakman and Keijer in Molecular Metabolism, it was argued that housing mice under close to standard conditions is the optimal way of modeling the human metabolic situation. This tenet was mainly based on the observation that humans usually display average metabolic rates of about 1.6 times basal metabolic rate. The extra heat thereby produced would also be expected to lead to a shift in the 'lower critical temperature' towards lower temperatures., Methods: To examine these tenets experimentally, we performed high time-resolution indirect calorimetry at different environmental temperatures on mice acclimated to different housing temperatures., Results: Based on the high time-resolution calorimetry analysis, we found that mice already under thermoneutral conditions display mean diurnal energy expenditure rates 1.8 times higher than basal metabolism, remarkably closely resembling the human situation. At any temperature below thermoneutrality, mice metabolism therefore exceeds the human equivalent: Mice under standard conditions display energy expenditure 3.1 times basal metabolism. The discrepancy to previous conclusions is probably attributable to earlier limitations in establishing true mouse basal metabolic rate, due to low time resolution. We also found that the fact that mean energy expenditure exceeds resting metabolic rate does not move the apparent thermoneutral zone (the lower critical temperature) downwards., Conclusions: We show that housing mice at thermoneutrality is an advantageous step towards aligning mouse energy metabolism to human energy metabolism., (Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Body temperature regulation involves the development of responses to cold and warm challenges. Matching our understanding of the development of body temperature regulation to warm challenges with that of cold challenges will enhance our understanding of the ontogeny of thermoregulation and reveal different adaptive specializations. Warm and cold thermoregulation are important processes, and they include direct thermal effects on offspring, as well as indirect effects on them, such as those imposed by thermally associated alterations of maternal behavior. The present paper is a selective review of the existing literature and a report of some new empirical data, aimed at processes of mammalian development, especially those affecting behavior. We briefly discuss the development of body temperature regulation in rats and mice, and thermal aspects of maternal behavior with emphasis on responses to high temperatures. The new data extend previous analyses of individual and group responses in developing rodents to warm and cool ambient temperatures. This literature not only reveals a variety of adaptive specializations during development, but it points to the earlier appearance in young mammals of abilities to combat heat loss, relative to protections from hyperthermia. These relative developmental delays in compensatory defenses to heating appear to render young mammals especially vulnerable to environmental warming. We describe cascading consequences of warming-effects that illustrate interactions across levels of physiological, neural, and behavioral development., (© 2017 Wiley Periodicals, Inc.)

Following the growing interest in the further development of manikins to simulate human thermal behaviour more adequately, thermo-physiological human simulators have been developed by coupling a thermal sweating manikin with a thermo-physiology model. Despite their availability and obvious advantages, the number of studies involving these devices is only marginal, which plausibly results from the high complexity of the development and evaluation process and need of multi-disciplinary expertise. The aim of this paper is to present an integrated approach to develop, validate and operate such devices including technical challenges and limitations of thermo-physiological human simulators, their application and measurement protocol, strategy for setting test scenarios, and the comparison to standard methods and human studies including details which have not been published so far. A physical manikin controlled by a human thermoregulation model overcame the limitations of mathematical clothing models and provided a complementary method to investigate thermal interactions between the human body, protective clothing, and its environment. The opportunities of these devices include not only realistic assessment of protective clothing assemblies and equipment but also potential application in many research fields ranging from biometeorology, automotive industry, environmental engineering, and urban climate to clinical and safety applications.

Older people are always more vulnerable to thermal-related discomfort and health issues because of their diminishing ability to adapt to varying environmental conditions. There exist a few thermoregulation models but most of them did not consider age and ethnic differences. In this study, a standard thermoregulation model for Chinese elders was developed on the basis of literature review and the already established model for the Chinese young people. Furthermore, the standard model was individualized with four parameters (height, weight, sex and age) for more accurate prediction. Besides, both models were validated with experimental data. Results show that the standard model prediction-measurement discrepancies of the skin temperatures lay in the range of S.D. of measurements. Compared to the standard model, there were some improvements in the individualized model, especially for old men. Further validation with published experimental data indicated good predictions were also in good agreement with measurements. The work in the paper may play an important role in providing a more healthy and comfortable indoor environment for the elderly., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Two mathematical models of human thermal regulation include the rational Predicted Heat Strain (PHS) and the thermophysiological model by Fiala. The approaches of the models are different, however, they both aim at providing predictions of the thermophysiological responses to thermal environments of an average person. The aim of this study was to compare and analyze predictions of the two models against experimental data. The analysis also includes a gender comparison. The experimental data comprised of ten participants (5 males, 5 females, average anthropometric values were used as input) conducting an intermittent protocol of rotating tasks (cycling, stacking, stepping and arm crank) of moderate metabolic activities (134-291W/m 2 ) with breaks in-between in a controlled environmental condition (34°C, 60% RH). The validation consisted of the predictions' comparison against experimental data from 2.5h of data of rectal temperature and mean skin temperature based on contact thermometry from four body locations. The PHS model over-predicted rectal temperatures during the first activity for males and the cooling effectiveness of sweat in the recovery periods, for both males and females. As a result, the PHS simulation underestimated the thermal strain in this context. The Fiala model accurately predicted the rectal temperature throughout the exposure. The fluctuation of the experimental mean skin temperature was not reflected in any of the models. However, the PHS simulation model showed better agreement than the Fiala model. As both models predicted responses more accurately for males than females, we suggest that in future development of the models it is important to take this result into account. The paper further discusses possible sources of the observed discrepancies and concludes with some suggestions for modifications., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

An amendment to this paper has been published and can be accessed via a link at the top of the paper [ABSTRACT FROM AUTHOR]

Phase change material is a high thermal storage substance, which can reduce temperature-related diseases of asphalt pavement when mixed with asphalt mixture. In this paper, NiTi alloy phase change heat-storage asphalt mixture (NiTi APCHAM) are prepared by using equal volume parts to replace fine asphalt aggregates partially with the NiTi alloy phase change energy-storage particles (NiTi APCEP). As the temperature increases, the specific heat capacity of NiTi APCHAM will increase first and then decrease due to the heat-storage effect of NiTi APCEP. The thermal conductivity coefficient of NiTi APCHAM shows a linear increasing trend with the increase in the substitution rate of NiTi APCEP. Adding NiTi APCEP in asphalt mixture can reduce its daily maximum temperature. Increasing admixture of NiTi APCEP in asphalt mixture can help to improve the phase change heat-storage thermoregulation capacity of the mixture. However, at a 6 wt% substitution rate of NiTi APCEP, the latent heat thermoregulation efficiency of NiTi APCEP reaches to maximum. With the increase in the content of NiTi APCEP, the Marshall stability of asphalt mixture gradually increases, and flexural-tensile strain at low temperature decreases gradually. By contrast, the water stability of the asphalt mixture is unaffected by the addition of NiTi APCEP. • NiTi alloy phase change heat-storage asphalt mixture were prepared. • Adding NiTi APCEP in asphalt mixture can reduce its daily maximum temperature. • The optimal substitution rate of NiTi APCEP was recommended in this paper. [ABSTRACT FROM AUTHOR]

Context: Diadromous fish populations in the Pacific Northwest face challenges along their migratory routes from declining habitat quality, harvest, and barriers to longitudinal connectivity. These stressors complicate the prioritization of proposed management actions intended to improve conditions for migratory fishes including anadromous salmon and trout. Objectives: We describe a multi-scale hybrid mechanistic–probabilistic simulation model linking migration corridor conditions to fish fitness outcomes. We demonstrate the model's utility using a case study of salmon and steelhead adults in the Columbia River migration corridor exposed to spatially- and temporally-varying stressors. Methods: The migration corridor simulation model is based on a behavioral decision tree that governs individual interactions with the environment, and an energetic submodel that estimates the hourly costs of migration. Emergent properties of the migration corridor simulation model include passage time, energy use, and survival. Results: We observed that the simulated fish's initial energy density, the migration corridor temperatures they experienced, and their history of behavioral thermoregulation were the primary determinants of their fitness outcomes. Insights gained from use of the model might be exploited to identify management interventions that increase successful migration outcomes. Conclusions: This paper describes new methods that extend the suite of tools available to aquatic biologists and conservation practitioners. We have developed a 2-dimensional spatially-explicit behavioral and physiological model and illustrated how it can be used to simulate fish migration within a river system. Our model can be used to evaluate trade-offs between behavioral thermoregulation and fish fitness at population scales. [ABSTRACT FROM AUTHOR]

The temperatures of black and white stripes on two zebras and a zebra hide were measured, throughout separate sunny days in Kenya. There is a 12–15oC difference between living zebras' stripe temperatures throughout the middle seven daytime hours. The hide temperatures reach 16oC higher than the living zebras. Like all equids, zebras sweat to keep cool. Movement of sweat away from the skin is accelerated by the recently discovered surfactant equid protein latherin, a vital component of cooling in racehorses. Latherin decreases the surface tension of the sweat, facilitating evaporative cooling at the hair tips. We suggest that the abrupt temperature difference between the stripes causes chaotic air movement above the hair surface, thus enhancing evaporative heat dissipation. This cooling mechanism explains the lower temperatures of living zebra stripes than those of the inanimate hide. We observed that the black stripes can be separately erected, while the white remain flat. This may further refine the mechanism. There is an ongoing debate about the function of zebra stripes, recently focussed on the fact that stripes deter biting flies. The data and observations in this paper suggest that the primary function of the stripes may be thermoregulation and a secondary benefit, fly-deterrence. [ABSTRACT FROM AUTHOR]

Introduction: TRPV1 receptors play a significant physiological role. To study pharmacological activity of new agonists and antagonists is important for the development of new drugs. This paper reports on the features of polypeptide antagonists of TRPV1 based on in vivo data. Materials and methods: The study was performed on 250 mature white ICR male mice weighing 25-30 g. Tests were conducted to evaluate the pharmacological activity and biological properties of APHC1-3 and a hybrid polypeptide A13 in thermal pain, inflammation and body temperature tests. Results and discussion: APHC1-3 polypeptides showed significant antinociceptive and analgesic activity in the dose range of 0.01-0.1 mg/kg, without causing hyperthermia. A single substitution of the aspartic acid residue of APHC1 polypeptide at position 23 by transferring one asparagine residue from the cognate peptide APHC3 led to a significant change in the properties of the molecule. A new polypeptide A13 did not alter the thermal sensitivity of the mice, but showed the most significant analgesic activity in the acid-induced pain model, unlike APHC1. A13 inhibits TRPV1 and affects body temperature as a classic antagonist of this receptor. Conclusion: Antagonistic properties of A13 became different from the properties of both initial analgesic polypeptides. Polypeptides APHC1-3 can be referred to as a new class of modulators of TRPV1, which produce a pronounced analgesic effect without hyperthermia. [ABSTRACT FROM AUTHOR]

This paper aims to improve the prediction of rectal temperature (Tre) from insulated skin temperature (Tis) and micro-climate temperature (Tmc) previously reported (Richmond et al., Insulated skin temperature as a measure of core body temperature for individuals wearing CBRN protective clothing. Physiol Meas 2013; 34:1531-43.) using additional physiological and/or environmental variables, under several clothing and climatic conditions. Twelve male (25.8 ± 5.1 years; 73.6 ± 11.5 kg; 178 ± 6 cm) and nine female (24.2 ± 5.1 years; 62.4 ± 11.5 kg; 169 ± 3 cm) volunteers completed six trials, each consisting of two 40-min periods of treadmill walking separated by a 20-min rest, wearing permeable or impermeable clothing, under neutral (25°C, 50%), moderate (35°C, 35%), and hot (40°C, 25%) conditions, with and without solar radiation (600 W m-2). Participants were measured for heart rate (HR) (Polar, Finland), skin temperature (Ts) at 11 sites, Tis (Grant, Cambridge, UK), and breathing rate (f) (Hidalgo, Cambridge, UK). Tmc and relative humidity were measured within the clothing. Tre was monitored as the 'gold standard' measure of Tc for industrial or military applications using a 10 cm flexible probe (Grant, Cambridge, UK). A stepwise multiple regression analysis was run to determine which of 30 variables (Tis, Ts at 11 sites, HR, f, Tmc, temperature, and humidity inside the clothing front and back, body mass, age, body fat, sex, clothing, Thermal comfort, sensation and perception, and sweat rate) were the strongest on which to base the model. Using a bootstrap methodology to develop the equation, the best model in terms of practicality and validity included Tis, Tmc, HR, and 'work' (0 = rest; 1 = exercise), predicting Tre with a standard error of the estimate of 0.27°C and adjusted r2 of 0.86. The sensitivity and specificity for predicting individuals who reached 39°C was 97 and 85%, respectively. Insulated skin temperature was the most important individual parameter for the prediction of Tre. This paper provides novel information about the viability of predicting Tc under a wide range of conditions, using predictors which can practically be measured in a field environment. [ABSTRACT FROM AUTHOR]

Copyright of Lege Artis Medicine (LAM) is the property of LifeTime Media Kft. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents an answer to a question on whether the use of plastic bags for thermoregulation in term neonates is effective in preventing hypothermia in a low-resource setting.

• Review the classification and requirements of PCMs for asphalt pavement thermoregulation. • Introduce the synthetic and characterization methods of CPCMs. • Review the effects of PCMs and CPCMs on asphalt pavement performance. • Discuss the challenges and potential development directions in this area. The regulation of asphalt pavement temperature is crucial in ensuring its durability, promoting traffic safety, and preserving the environment. Phase change materials (PCMs) can play a critical role in preventing thermal distress of asphalt pavements as thermoregulation units. This paper presents a comprehensive review of the classification and performance requirements of PCMs and the methods of synthetic and characterization of composite PCMs (CPCMs). Furthermore, the study delves into the thermoregulation effect of CPCMs and its influence on the performance of asphalt pavements. Results show that the organic solid–liquid PCMs and organic-organic eutectic PCMs meet the requirements of asphalt pavement in terms of phase change temperature, latent heat, thermal conductivity, durability, environmental compatibility, and economic viability, and therefore have a wide range of applications. However, the direct incorporation of PCMs can significantly affect both the performance and thermoregulation properties of the asphalt pavement. Therefore, it is crucial to utilize various methods to prepare CPCMs to avoid liquid leakage. The thermoregulation effect of CPCMs on asphalt pavements can be validated through both experimental characterization and numerical simulation, and the improvement in the mechanical strength of CPCMs holds potential for enhancing the rheological properties and overall performance of asphalt pavements. Furthermore, this paper provides an in-depth analysis of the areas in which CPCM preparation methods, performance characterization, and engineering applications still require further research. It is intended that this paper will serve as a valuable resource for relevant professionals and contribute to the advancement of knowledge in this field. [ABSTRACT FROM AUTHOR]

Around 40% of total energy consumption in the UK is consumed by creating comfortable indoor environment for occupants. Occupants’ behaviour in terms of achieving thermal comfort could have a significant impact on a building’s energy consumption. Therefore, understanding the interactions of occupants with their buildings would be essential to provide a thermal comfort environment that is less reliance on energy-intensive heating, ventilation and air-conditioning systems, to meet energy-saving and carbon emission targets. This paper presents the findings of a year-long field study conducted in non-air-conditioned office buildings in the UK. Occupants’ adaptive responses in terms of technological and personal dimensions are dynamic processes which could vary with both indoor and outdoor thermal conditions. The adaptive behaviours of occupants in the surveyed building show substantial seasonal and daily variations. Our study shows that non-physical factors such as habit could influence the adaptive responses of occupants. However, occupants sometimes displayed inappropriate adaptive behaviour, which could lead to a misuse of energy. This paper attempts to illustrate how occupants would adapt and interact with their built environment and consequently contribute to development of a guide for future design/refurbishment of buildings and to develop energy management systems for a comfortable built environment. [ABSTRACT FROM PUBLISHER]

Purpose – People working in the hot environment are constantly exposed to the overheating, that can lead to cardiovascular disorders and as a consequence result in occupational diseases. The purpose of this paper is to present developed personal liquid cooling system that is able to efficiently draw excess heat from the human organism, protecting against thermal stress. Design/methodology/approach – The paper presents study concerning the assessment of effect of the coolant temperature in the developed liquid cooling garment (LCG) on physiological parameters of the subjects (heart rate, body temperature, skin temperature) and parameters of the undergarment microclimate, as well as subjective sensations reported by volunteers exercising in hot microclimate while wearing LCG and without LCG. Findings – Obtained results of physiological parameters measurements, as well as undergarment physical parameters and volunteers subjective sensations, proved satisfactory level of thermal stress reduction while working in the aluminized protective clothing in hot environment by the developed personal liquid cooling system for the variant with coolant temperature 19°C and the flow rate 0.9 dm3/min. Originality/value – This paper presents a new clothing construction intended for LCG that can efficiently support human thermoregulation processes while working in the hot environment. [ABSTRACT FROM AUTHOR]

The laboratory mouse has become the predominant test species in biomedical research. The number of papers that translate or extrapolate data from mouse to human has grown exponentially since the year 2000. There are many physiological and anatomical factors to consider in the process of extrapolating data from one species to another. Body temperature is, of course, a critical determinant in extrapolation because it has a direct impact on metabolism, cardiovascular function, drug efficacy, pharmacokinetics of toxins and drugs, and many other effects. While most would consider the thermoregulatory system of mice to be sufficiently stable and predictable as to not be a cause for concern, the thermal physiology of mice does in fact present unique challenges to the biomedical researcher. A variable and unstable core temperature, high metabolic rate, preference for warm temperatures, large surface area: body mass ratio, and high rate of thermal conductance, are some of the key factors of mice that can affect the interpretation and translation of data to humans. It is the intent of this brief review to enlighten researchers studying interspecies translation of biomedical data on the salient facets of the mouse thermal physiology and show how extrapolation in fields such as physiology, psychology, nutrition, pharmacology, toxicology, and pathology., (Published by Elsevier Inc.)

This paper aims to integrate a human thermoregulatory model with a clothing model to predict core and skin temperatures. The human thermoregulatory model, consisting of an active system and a passive system, was used to determine the thermoregulation and heat exchanges within the body. The clothing model simulated heat and moisture transfer from the human skin to the environment through the microenvironment and fabric. In this clothing model, the air gap between skin and clothing, as well as clothing properties such as thickness, thermal conductivity, density, porosity, and tortuosity were taken into consideration. The simulated core and mean skin temperatures were compared to the published experimental results of subject tests at three levels of ambient temperatures of 20 °C, 30 °C, and 40 °C. Although lower signal-to-noise-ratio was observed, the developed model demonstrated positive performance at predicting core temperatures with a maximum difference between the simulations and measurements of no more than 0.43 °C. Generally, the current model predicted the mean skin temperatures with reasonable accuracy. It could be applied to predict human physiological responses and assess thermal comfort and heat stress., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The genesis of the present research paper is to develop a revised exact analytical solution of thermal profile of 1-D Pennes' bioheat equation (PBHE) for living tissues influenced in thermal therapeutic treatments. In order to illustrate the temperature distribution in living tissue both Fourier and non-Fourier model of 1-D PBHE has been solved by 'Separation of variables' technique. Till date most of the research works have been carried out with the constant initial steady temperature of tissue which is not at all relevant for the biological body due to its nonhomogeneous living cells. There should be a temperature variation in the body before the therapeutic treatment. Therefore, a coupled heat transfer in skin surface before therapeutic heating must be taken account for establishment of exact temperature propagation. This approach has not yet been considered in any research work. In this work, an initial condition for solving governing differential equation of heat conduction in biological tissues has been represented as a function of spatial coordinate. In a few research work, initial temperature distribution with PBHE has been coupled in such a way that it eliminates metabolic heat generation. The study has been devoted to establish the comparison of thermal profile between present approach and published theoretical approach for particular initial and boundary conditions inflicted in this investigation. It has been studied that maximum temperature difference of existing approach for Fourier temperature distribution is 19.6% while in case of non-Fourier, it is 52.8%. We have validated our present analysis with experimental results and it has been observed that the temperature response based on the spatial dependent variable initial condition matches more accurately than other approaches., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Thermoregulation models of the human body have been widely used in thermal comfort studies. The existing models are complicated and not fully verified for application in China. This paper presents a simplified thermoregulation model which has been statistically validated by the predicted and measured mean skin temperature in warm environments, including 21 typical conditions with 400 Chinese subjects. This model comprises three parts: i) the physical model; ii) the controlled system; and iii) the controlling system, and considers three key questions formerly ignored by the existing models including: a) the evaporation efficiency of regulatory sweat; b) the proportional relation of total skin blood flow and total heat loss by regulatory sweating against body surface area; and c) discrepancies in the mean skin temperatures by gender. The developed model has been validated to be within the 95% confidence interval of the population mean skin temperature in three cases., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Local thermal sensation modeling gained importance due to developments in personalized and locally applied heating and cooling systems in office environments. The accuracy of these models depends on skin temperature prediction by thermophysiological models, which in turn rely on accurate environmental and personal input data. Environmental parameters are measured or prescribed, but personal factors such as clothing properties and metabolic rates have to be estimated. Data for estimating the overall values of clothing properties and metabolic rates are available in several papers and standards. However, local values are more difficult to retrieve. For local clothing, this study revealed that full and consistent data sets are not available in the published literature for typical office clothing sets. Furthermore, the values for local heat production were not verified for characteristic office activities, but were adapted empirically. Further analyses showed that variations in input parameters can lead to local skin temperature differences (∆T skin,loc  = 0.4-4.4°C). These differences can affect the local sensation output, where ∆T skin,loc  = 1°C is approximately one step on a 9-point thermal sensation scale. In conclusion, future research should include a systematic study of local clothing properties and the development of feasible methods for measuring and validating local heat production., (© 2016 The Authors. Indoor Air published by John Wiley & Sons Ltd.)

In my 2015 editorial, I selected two research publications with a focus on an applied sports sciences perspective. This year I have chosen to focus on two publications from a methodological viewpoint, highlighting the importance of laboratory procedures and extraction of data through a systematic review respectively. The first publication by Leites and colleagues (J Appl Physiol) addresses questions in relation to thermoregulation and carbohydrate metabolism in young people. This topic is difficult to conduct due to additional ethical and safety concerns due to exercising in the heat. Nonetheless, there are important basic science questions to be answered. Using a range of measurement techniques including rectal thermometry, 13 C-enriched carbohydrate isotopes and procedures to standardize the heat stress equally between a group of men and boys, this project demonstrates an exemplary range of experimental skills. In my second selected paper by Lesinski et al., (Brit J Sports Med), both a systematic review and a meta-analyses were conducted to investigate the dose-response relationships of resistance training on physical performance in youth athletes. As the requirement for more evidence based practice is demanded, the move away from a narrative review to a more methodological and rigorous approach is to be encouraged. It is, in my opinion, a skill that we should be encouraging all our early career pediatric researchers to learn from the outset, the outcome of which can only make our discipline stronger.

Dramatic relief of autistic behavior by infectious fever continues to tantalize parents and practitioners, yet researchers still hesitate to study its physiology/biochemistry, fearing stress and heat of brain imaging, contagion, and fever's complexity. Yet what could be more revealing than a common event that virtually 'normalizes' autistic behavior for a time? This paper proposes study of three simplified scenarios: (1) improvements appearing hours before fever, (2) return of autistic behavior soon after fever, (3) improvements persisting long after fever. Each scenario limits some risk - and some explanation - inviting triangulation of decisive factor(s) in relief and recurrence. Return of autistic behavior after fever may be most revealing. The complex mechanisms that generated fever have all abated; simpler cooling mechanisms prevail - how many plausible explanations can there be? The decisive factor in fever's benefit is concluded to be water drawn/carried from brain myelin and astrocytes by osmolytes glutamine and taurine released from muscles and brain; the decisive factor in return of autistic behavior after fever is return of water., (Copyright © 2016 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)

Background: The aim of this study was to review the literature on the association between hypothermia and outcomes in open and endovascular abdominal aortic aneurysm (AAA) repair. The secondary aim was to determine whether there is a difference in body temperature in patients undergoing either transperitoneal (TP), retroperitoneal (RP), or endovascular surgical repair of the abdominal aorta (EVAR)., Methods: MEDLINE, Web of Science, and Trip searched for all studies on temperature in the context of aortic surgery or endovascular aortic interventions. To be included in the review, the papers had to be related to intraoperative or postoperative hypothermia and/or normothermia, with regards to either open or endovascular repair of the abdominal aorta. Thoracic or thoracoabdominal aortic repairs were not included for review., Results: Eight studies involving 765 patients were eligible. Of these, 6 studies looked at open elective AAA repair involving 605 patients. Only 2 studies investigated emergency AAA repair and consisted of 160 patients where only 35 of those patients underwent emergency EVAR. Normothermic patients had a shorter length of stay in the intensive care unit (P = 0.0008), while hypothermia was independently associated with higher rates of organ dysfunction, in-hospital mortality, and prolonged hospital length of stay. In ruptured AAAs, the lowest average intraoperative temperature was recorded in open repair compared with EVAR (P = 0.02). There was no statistically significant difference in postoperative temperature between patients undergoing elective RP repair and those having TP surgery., Conclusions: The studies identified in this review have shown that hypothermia has numerous deleterious effects on outcomes in AAA repair - whether or not these adverse outcomes are those such as higher rates of organ dysfunction, mortality or prolonged hospital length of stay, can only be done at the single paper level and not at a literature review level, due to multiple confounding variables. Despite these limitations, the benefits of this review are numerous. This article highlights the importance of core body temperature and outcomes of AAA repair. Furthermore, it brings forth the need to standardize the method of core body temperature measurement and method of rewarming. Given the body of evidence so far, these standardized data collection points will be important for national vascular quality improvement initiatives. Only through rigorous analysis of standardized dataset can firm recommendation regarding peri- and postoperative temperature management be made., (Copyright © 2016 Elsevier Inc. All rights reserved.)