Muñoz Zamora et al.'s study^([1])is the first to investigate how cognitive processes can directly affect thermoregulation.By combining behavioral conditioning,engram labeling,and neural manipulation technique...Muñoz Zamora et al.'s study^([1])is the first to investigate how cognitive processes can directly affect thermoregulation.By combining behavioral conditioning,engram labeling,and neural manipulation techniques,the authors demonstrate that mice are capable of can form and retrieve memories of cold environments.Remarkably,recalling these memories induces metabolic responses typically associated with actual cold exposure.This work represents a significant advancement in our understanding of brain,body interactions,particularly in how learned experiences can modulate fundamental homeostatic processes.The findings have broad implications across multiple fields of neuroscience and physiology.展开更多
The application of thermoelectric devices(TEDs)for personalized thermoregulation is attractive for saving energy while balancing the quality of life.TEDs that directly attach to human skin remarkably minimized the ene...The application of thermoelectric devices(TEDs)for personalized thermoregulation is attractive for saving energy while balancing the quality of life.TEDs that directly attach to human skin remarkably minimized the energy wasted for cooling the entire environment.However,facing the extreme dynamic geometry change and strain of human skin,conventional TEDs cannot align with the contour of our bodies for the best thermoregulation effect.Hence,we designed a kirigami-based wearable TED with excellent water vapor permeability,flexibility,and conformability.Numerical analysis and experimental results reveal that our product can withstand various types of large mechanical deformation without circuit rupture.The stated outcome and proposed facile approach not only reinforce the development of wearable TEDs but also offer an innovative opportunity for different electronics that require high conformability.展开更多
Extending recent findings that reptile embryos seek optimal temperatures inside eggs for thermoregulation,our study demonstrates that this thermoregulatory behaviour can be affected by the amount of oxygen available t...Extending recent findings that reptile embryos seek optimal temperatures inside eggs for thermoregulation,our study demonstrates that this thermoregulatory behaviour can be affected by the amount of oxygen available to an embryo.We exposed embryos of a freshwater turtle(Mauremys reevesii)to two heat sources(an optimal temperature of 30°C and a high temperature of 33°C)under three different oxygen levels–hypoxia(12%O2),normoxia(21%O2)and hyperoxia(30%O2)–and quantified the interactive effects of temperature and oxygen availability on embryonic thermoregulatory behaviour.Our results demonstrated that,in both thermal treatments,embryos exposed to hypoxia did not move as close to the heat source and therefore selected lower temperatures than those exposed to normoxia or hyperoxia.Embryos may select low temperatures under hypoxic conditions to decrease oxygen consumption and therefore alleviate the negative impact of hypoxic stress.展开更多
In the paper a new two-dimensional 'man-WCV'(water cooling vest) mathematical model is developed. This model is of practical use: it can predict transient temperature responses and body temperature distributio...In the paper a new two-dimensional 'man-WCV'(water cooling vest) mathematical model is developed. This model is of practical use: it can predict transient temperature responses and body temperature distribution for a person in a nonuniform hot environment, doing various jobs and dressed in different clothes. In addition, the results calculated from the model can be used to optimize the distribution of the tube-net lined on the WCV and to evaluate an individual thermal conditioning system with cooling water. The results obtained from the model agree well with the author's experimental data.展开更多
A three-dimensional thermoregulation mathematical model of temperature fluctuations for the human body is developed based on predecessors＇ thermal models. The following improvements are necessary in real situations：...A three-dimensional thermoregulation mathematical model of temperature fluctuations for the human body is developed based on predecessors＇ thermal models. The following improvements are necessary in real situations： ellipsoids and elliptical cylinders are used to adequately approximate body geometry, divided into 18 segments and five layers; the core layer consists of the organs; the pulsation of the heart cycle, the pulsatile laminar flow, the peripheral resistance, and the thermal effect of food are considered. The model is calculated by adopting computational fluid dynamics（CFD） technology, and the results of the model match with the experimental data. This paper can give a reasonable explanation for the temperature fluctuations.展开更多
Metabolisms play a vital role in thermoregulation in the human body. The metabolic rate varies with the activity levels and has different behaviors in nature depending on the physical activities of the person. During ...Metabolisms play a vital role in thermoregulation in the human body. The metabolic rate varies with the activity levels and has different behaviors in nature depending on the physical activities of the person. During the activity, metabolic rate increases rapidly at the beginning and then increases slowly to become almost constant after a certain time. So, its behavior is as logistics in nature. The high metabolic rate during activity causes the increase of body core temperature up to 39˚C <a href="#ref1">[1] <a href="#ref2">[2]. The logistic model of metabolic rate is used to re-model Pennes’ bioheat equation for the study of temperature distribution in three layered human dermal parts during carpentering, swimming and marathon. The finite element method is used to obtain the solution of the model equation. The results demonstrate that there is a significant change in tissue temperature due to sweating and ambient temperature variations.展开更多
Dear Editor,Traditional studies on animal behavior mainly focus on the post-hatching phase of the life history,assuming that embryos are works-in-progress,despite most animals spending a significant time developing em...Dear Editor,Traditional studies on animal behavior mainly focus on the post-hatching phase of the life history,assuming that embryos are works-in-progress,despite most animals spending a significant time developing embryos inside an egg or mother's body(Du&Shine 2022).Although embryos are thought to be passive to their environment,several studies have demonstrated that behavioral thermoregulation occurs in embryonic reptiles and birds(Du et al.2011;Zhao et al.2013;Li et al.2014).Behavioral thermoregulation may enable embryos to develop at suitable temperatures,thereby increasing their developmental success(Du et al.2011).Second,behavioral thermoregulation by embryos is expected to produce hatchlings with better performance and higher fitness(Ye et al.2019;Liu et al.2023).For example,in species that exhibit temperature-dependent sex determination,behavioral thermoregulation may enable embryos to select suitable temperatures to fine-tune sexual differentiation,thereby expanding the range of nest temperatures that produce equal offspring sex ratios(Ye et al.2019).展开更多
With the rise of optogenetic manipulation of neurons,the effects of optogenetic heating on temperature-sensitive physi-ological processes,and the damage to surrounding tissues have been neglected.This manuscript repor...With the rise of optogenetic manipulation of neurons,the effects of optogenetic heating on temperature-sensitive physi-ological processes,and the damage to surrounding tissues have been neglected.This manuscript reports the fabrication of a highly temperature-sensitive semi-interpenetrating optical hydrogel fiber(TSOHF)using the integrated dynamic wet-spinning technique.TSOHF exhibits a structural tunable diameter,clear core/sheath structure,tunable temperature-sensitivity,excellent light propagation property(0.35 dB cm^(-1),650 nm laser light),and good biocompatibility(including tissue-like Young’s modulus,stable dimensional stability,and low cytotoxicity).Based on these properties,a potential application of optogenetic regulation of neural tissue(hypoglossal nerve),with controllable temperature using TSOHF was designed and performed.Further,this work provides new insight into molecular design and a practical approach to continually manufacture a temperature-sensitive hydrogel optical fiber for applications in intelligent photomedicine.展开更多
The thermoregulation behavior ofLucilia sericata larvae （Diptera： Calliphori- dae）, a necrophagous species that feeds on vertebrate cadavers, was investigated. These larvae require high heat incomes to develop, and...The thermoregulation behavior ofLucilia sericata larvae （Diptera： Calliphori- dae）, a necrophagous species that feeds on vertebrate cadavers, was investigated. These larvae require high heat incomes to develop, and can elevate temperatures by forming large aggregates. We hypothesized that L. sericata larvae should continue to feed at temperatures up to 38 ℃, which can be reached inside larval masses. Thermal regulation behavior such as movement between a hot food spot and colder areas was also postulated. The hypotheses were tested by tracking for 1 h the activity of single, starved third instar larvae in a Petri dish containing 1 food spot （FS） that was heated to a constant temperature of 25 ℃, 34 ℃ or 38 ℃ with an ambient temperature of 25 ℃. The influence of previous conspecific activity in the food on larval behavior was also tested. The crops of larvae were dissected to monitor food content in the digestive systems. Based on relative crop measurements, larvae fed at all food temperatures, but temperature strongly affected larval behavior and kinematics. The total time spent by larvae in FS and the duration of each stay decreased at high FS temperature. Previous activity of conspecifics in the food slightly increased the time spent by larvae in FS and also decreased the average distance to FS. Therefore, necrophagous L. sericata larvae likely thermoregulate during normal feeding activities by adjusting to local fluctuations in temperature, particularly inside maggot masses. By maintaining a steady internal body temperature, larvae likely reduce their development time.展开更多
Background Although not universal,active care is being offered to infants weighing<500 g at birth,referred to as ultra-low birth weight(ULBW)infants appropriate for gestational age.These infants have the greatest r...Background Although not universal,active care is being offered to infants weighing<500 g at birth,referred to as ultra-low birth weight(ULBW)infants appropriate for gestational age.These infants have the greatest risk of dying or developing major morbidities.ULBW infants face challenges related to fluid and heat loss as well as skin injury in the initial days of life from extreme anatomical and physiological immaturity of the skin.Although there is an emerging literature on the outcomes of ULBW infants,there is a paucity of evidence to inform practice guidelines for delivering optimal care to this cohort of infants.Data sources A comprehensive review of the literature was performed using the PubMed and Embase databases.Searched keywords included“thermoregulation or body temperature regulation”,“incubator humidity”,“skin care”,“infant,extremely low birth weight”and“ultra-low birth weight infants”.Results Evidences for thermoregulation,incubator humidity,and skincare practices are available for preterm infants weighing<1500 g at birth but not specifically for ULBW infants.Studies on thermoregulation,incubator humidity,or skincare practices had a small sample size and did not include a sub-group analysis for ULBW infants.Current practice recommendations in ULBW infants are adopted from research in very and/or extremely low birth weight infants.Conclusions This narrative review focuses on challenges in thermoregulation,incubator humidity,and skincare practices in ULBW infants,highlights current research gaps and suggests potential developments for informing practices for improving health outcomes in ULBW infants.展开更多
The brood-parasitic brown-headed cowbird(Molothrus ater)has one of the shortest incubation periods of any bird.Brown-headed cowbird eggs,and those of other avian brood parasites,tend to be more spherical due to their ...The brood-parasitic brown-headed cowbird(Molothrus ater)has one of the shortest incubation periods of any bird.Brown-headed cowbird eggs,and those of other avian brood parasites,tend to be more spherical due to their greater relative width.The traditional explanation for this egg shape is that it,combined with the thicker eggshells,resists host puncture-ejection.However,very few North American hosts of the brownheaded cowbird actually engage in puncture-ejection and therefore wider eggs may instead provide greater contact with a host’s brood patch during incubation,especially in large host nests.We tested whether greater egg width increased mean temperature and reduced temperature variation in brown-headed cowbirds by inserting temperature probes into brown-headed cowbird and house sparrow(Passer domesticus)eggs and placing them into red-winged blackbird(Agelaius phoeniceus)nests.House sparrow eggs are similar in appearance and in length to cowbird eggs,but are not as wide.We found no signifcant relationship between brown-headed cowbird egg width and mean incubation temperature.However,brown-headed cowbird eggs experienced less temperature variation than house sparrow eggs,and within brown-headed cowbird eggs,more spherical eggs experienced less temperature variation when accounting for differences in width.These results suggest that brownheaded cowbirds may have short incubation periods in part because their eggs exhibit less temperature variation over the course of incubation.The brown-headed cowbird’s egg shape may contribute to its accelerated embryonic development rate relative to host eggs of similar size,which explains its ability to hatch in a variety of host nests.展开更多
Non-signaling functions of coloration include thermoregulation(thermal melanism hypothesis),protection against ultraviolet radiation(photoprotection hypothesis),and concealment from predators(crypsis hypothesis).We in...Non-signaling functions of coloration include thermoregulation(thermal melanism hypothesis),protection against ultraviolet radiation(photoprotection hypothesis),and concealment from predators(crypsis hypothesis).We investigated whether dorsal coloration in 19 populations of spiny-footed lizards,Acanthodactylus erythrurus,across the Iberian Peninsula varies according to these functions.We captured adult males and females in each population and calculated standardized dorsum brightness estimates from photographs.We also calculated standardized ground luminosity estimates and gathered information on latitude,altitude,mean annual temperature,and mean annual solar radiation for each location.Males showed a higher percentage of black coloration and a more contrasted dorsum than females,suggesting different selection pressures on dorsal coloration in both sexes.Furthermore,males showed a darker dorsum and a higher percentage of black coloration at higher altitudes and when the ground was darker.In contrast,females exhibited a darker dorsum only when the ground was darker and a higher percentage of black coloration only at higher altitudes.We also observed that the variation of dorsum luminosity within males and the variation of dorsum luminosity among females within populations were both positively related to the variation of ground luminosity among different points within locations.Latitude,temperature,and solar radiation were not signifcantly related to dorsal coloration in either sex.Our results support the photoprotection and crypsis hypotheses in males and,to some extent,in females,whereas the thermal melanism hypothesis is weakly supported in both sexes.These fndings suggest that there is local adaptation in the dorsal coloration of the spiny-footed lizard.展开更多
The local skin temperatures of 22 subjects at air temperatures of 21,24,26,29 ℃ are measured,and the mean skin temperatures are calculated by ten skin temperature measuring points.The thermal comfort levels and the t...The local skin temperatures of 22 subjects at air temperatures of 21,24,26,29 ℃ are measured,and the mean skin temperatures are calculated by ten skin temperature measuring points.The thermal comfort levels and the thermal sensations of these subjects are also investigated by a questionnaire.The Mahalanobis distance discrimination method is applied to establish the evaluation model for the thermal comfort based on the mean skin temperature.The experimental results indicate that the difference of the mean skin temperatures between the comfort level and the discomfort level is significant.Using the evaluation model,the mean skin temperature at the thermal comfort level is 32.6 to 33.7 ℃,and the thermal comfort levels of 72% of the subjects are correctly evaluated.The accuracy of the evaluation model can be improved when the effects of sex of the subject on the mean skin temperature and the thermal comfort are considered.It can be concluded that the mean skin temperature can be used as an effective physiological indicator to evaluate human thermal comfort in a steady thermal environment.展开更多
Growing concern about the influence of climate change on flowering plants, pollinators, and the mutualistic interac- tions between them has led to a recent surge in research. Much of this research has addressed the co...Growing concern about the influence of climate change on flowering plants, pollinators, and the mutualistic interac- tions between them has led to a recent surge in research. Much of this research has addressed the consequences of warming for phenological and distributional shifts. In contrast, relatively little is known about the physiological responses of plants and insect pollinators to climate warming and, in particular, how these responses might affect plant-pollinator interactions. Here, we summa- rize the direct physiological effects of temperature on flowering plants and pollinating insects to highlight ways in which plant and pollinator responses could affect floral resources for pollinators, and pollination success for plants, respectively. We also con- sider the overall effects of these responses on plant-pollinator interaction networks. Plant responses to wanning, which include altered flower, nectar, and pollen production, could modify floral resource availability and reproductive output of pollinating in- sects. Similarly, pollinator responses, such as altered foraging activity, body size, and life span, could affect patterns of pollen flow and pollination success of flowering plants. As a result, network structure could be altered as interactions are gained and lost, weakened and strengthened, even without the gain or loss of species or temporal overlap. Future research that addresses not only how plant and pollinator physiology are affected by warming but also how responses scale up to affect interactions and networks should allow us to better understand and predict the effects of climate change on this important ecosystem service .展开更多
Acute exposure to heat, such as that experienced by people arriving into a hotter or more humid environment, can compromise physical and cognitive performance as well as health. In military contexts heat stress is exa...Acute exposure to heat, such as that experienced by people arriving into a hotter or more humid environment, can compromise physical and cognitive performance as well as health. In military contexts heat stress is exacerbated by the combination of protective clothing, carried loads, and unique activity profiles, making them susceptible to heat illnesses. As the operational environment is dynamic and unpredictable, strategies to minimize the effects of heat should be planned and conducted prior to deployment. This review explores how heat acclimation(HA) prior to deployment may attenuate the effects of heat by initiating physiological and behavioural adaptations to more efficiently and effectively protect thermal homeostasis, thereby improving performance and reducing heat illness risk. HA usually requires access to heat chamber facilities and takes weeks to conduct, which can often make it impractical and infeasible, especially if there are other training requirements and expectations. Recent research in athletic populations has produced protocols that are more feasible and accessible by reducing the time taken to induce adaptations, as well as exploring new methods such as passive HA. These protocols use shorter HA periods or minimise additional training requirements respectively, while still invoking key physiological adaptations, such as lowered core temperature, reduced heart rate and increased sweat rate at a given intensity. For deployments of special units at short notice(< 1 day) it might be optimal to use heat re-acclimation to maintain an elevated baseline of heat tolerance for long periods in anticipation of such an event. Methods practical for military groups are yet to be fully understood, therefore further investigation into the effectiveness of HA methods is required to establish the most effective and feasible approach to implement them within military groups.展开更多
Maintaining thermal comfort within the human body is crucial for optimal health and overall well-being.By merely broadening the setpoint of indoor temperatures,we could significantly slash energy usage in building hea...Maintaining thermal comfort within the human body is crucial for optimal health and overall well-being.By merely broadening the setpoint of indoor temperatures,we could significantly slash energy usage in building heating,ventilation,and air-conditioning systems.In recent years,there has been a surge in advancements in personal thermal management(PTM),aiming to regulate heat and moisture transfer within our immediate surroundings,clothing,and skin.The advent of PTM is driven by the rapid development in nano/micro-materials and energy science and engineering.An emerging research area in PTM is personal radiative thermal management(PRTM),which demonstrates immense potential with its high radiative heat transfer efficiency and ease of regulation.However,it is less taken into account in traditional textiles,and there currently lies a gap in our knowledge and understanding of PRTM.In this review,we aim to present a thorough analysis of advanced textile materials and technologies for PRTM.Specifically,we will introduce and discuss the underlying radiation heat transfer mechanisms,fabrication methods of textiles,and various indoor/outdoor applications in light of their different regulation functionalities,including radiative cooling,radiative heating,and dual-mode thermoregulation.Furthermore,we will shine a light on the current hurdles,propose potential strategies,and delve into future technology trends for PRTM with an emphasis on functionalities and applications.展开更多
This paper presents design and simulation of a switchable radiative cooler that exploits phase transition in vanadium di-oxide to turn on and off in response to temperature.The cooler consists of an emitter and a sola...This paper presents design and simulation of a switchable radiative cooler that exploits phase transition in vanadium di-oxide to turn on and off in response to temperature.The cooler consists of an emitter and a solar reflector separated by a spacer.The emitter and the reflector play a role of emitting energy in mid-infrared and blocking incoming solar energy in ultraviolet to near-infrared regime,respectively.Because of the phase transition of doped vanadium dioxide at room tem-perature,the emitter radiates its thermal energy only when the temperature is above the phase transition temperature.The feasibility of cooling is simulated using real outdoor conditions.We confirme that the switchable cooler can keep a desired temperature,despite change in environmental conditions.展开更多
The big-headed turtle Platysternon megacephalum is a stream-dwelling species whose ecology is poorly known. We carried out field and laboratory investigations to determine field body temperatures and thermal preferenc...The big-headed turtle Platysternon megacephalum is a stream-dwelling species whose ecology is poorly known. We carried out field and laboratory investigations to determine field body temperatures and thermal preference of this species. In the field, the body temperatures of the turtles conformed to the water temperature, with little diel variation in either summer or au- tumn. Over the diel cycle, the mean body temperatures ranged from 20.8℃ to 22.2℃ in summer and from 19.3℃ to 21.2℃ in autumn; the highest body temperatures ranged from 22.1℃ to 25.0℃ in summer and from 20.6℃ to 23.8℃ in autumn. In the laboratory, the preferred body temperature （Tp） was 25.3℃ Food intake was maximized at 24.0℃, whereas locomotor perfor- mance peaked at 30.0℃. Consequently, Tp was closer to the thermal optimum for food intake than for locomotion. Therefore, this freshwater turtle has relative low field body temperatures corresponding to its thermal environment. In addition, the turtle prefers low temperatures and has a low optimal temperature for food intake [Current Zoology 59 （5）： 626-632, 20＇13].展开更多
Purpose: The purpose of this study was to examine the effects of pre-cooling and fluid replacement with either crushed ice or cold water.Methods: On 2 separate occasions, in a counterbalanced order, 9 recreationally-t...Purpose: The purpose of this study was to examine the effects of pre-cooling and fluid replacement with either crushed ice or cold water.Methods: On 2 separate occasions, in a counterbalanced order, 9 recreationally-trained males ingested 1.25 g/kg(80–100 g) of either crushed ice(0.5℃)or cold water(4℃) every 5 min for 30 min before exercise. They also ingested 2.0 g/kg(130–160 g) of the same treatment drink at 15 min, 30 min, and45 min after the commencement of cycling to exhaustion at 60%VO_(2max) until voluntary exhaustion in a hot environment(35℃ and 30% relative humidity).Results: The cycling time to exhaustion in the crushed ice trial(50.0 ± 12.2 min) was longer than the cold water trial(42.2 ± 10.1 min; p = 0.02).Although the rectal temperature fell by 0.37℃± 0.03℃(p = 0.01) at the end of the resting period after the crushed ice ingestion, the rates of rise in rectal temperature during the exercise period were not significantly different between these 2 conditions(crushed ice: 0.23℃± 0.07℃, 5 min;cold water: 0.22℃± 0.07℃, 5 min; p = 0.94).Conclusion: Crushed ice ingestion before and during exercise in a hot environment may be a preferred and effective approach for minimizing thermal strain, and for improving endurance performance as compared with cold water ingestion.展开更多
Chemical resistant textiles are vital for safeguarding humans against chemical hazards in various settings.such as industrialproduction,chemicalaccidents,laboratory activities,and road transportation.However,the ideal...Chemical resistant textiles are vital for safeguarding humans against chemical hazards in various settings.such as industrialproduction,chemicalaccidents,laboratory activities,and road transportation.However,the ideal integration of chemical resistance,thermal and moisture management,and wearer condition monitoring in conventional chemically protective textiles remains challenging.Herein,the design,manufacturing,and use of stretchable hierarchical core-shell yarns(HCSYs)for integrated chemical resistance,moisture regulation,and smart sensing textiles are demonstrated.These yarns con-tain helically elastic spandex,wrapped silver-plated nylon,and surface-structuredpolytetrafluo-roethylene(PTFE)yarns and are designed and manufactured based on a scalable fabrication process.In addition to their ideal chemical resistance performance,HCSYs can function as multifunctional stretch-able electronics for real-time human motion monitoring and as the basic element of intelligent textiles.Furthermore,a desirable dynamic thermoregulation function is achieved by exploiting the fabric structure with stretching modulation.Our HCSYs may provide prospective opportunities for the future development of smart protective textiles with high durability,flexibility,and scalability.展开更多
文摘Muñoz Zamora et al.'s study^([1])is the first to investigate how cognitive processes can directly affect thermoregulation.By combining behavioral conditioning,engram labeling,and neural manipulation techniques,the authors demonstrate that mice are capable of can form and retrieve memories of cold environments.Remarkably,recalling these memories induces metabolic responses typically associated with actual cold exposure.This work represents a significant advancement in our understanding of brain,body interactions,particularly in how learned experiences can modulate fundamental homeostatic processes.The findings have broad implications across multiple fields of neuroscience and physiology.
基金supported by the National Natural Science Foundation of China(No.62122002)the Project of City University of Hong Kong(Nos.9667221,9678274,and 9680322)+1 种基金as part of the InnoHK Project on Project 2.2—AI-based 3D ultrasound imaging algorithm at Hong Kong Centre for Cerebro-Cardiovascular Health Engineering(COCHE)the Project of Research Grants Council of the Hong Kong Special Administrative Region(Nos.11213721,11215722,and 11211523)。
文摘The application of thermoelectric devices(TEDs)for personalized thermoregulation is attractive for saving energy while balancing the quality of life.TEDs that directly attach to human skin remarkably minimized the energy wasted for cooling the entire environment.However,facing the extreme dynamic geometry change and strain of human skin,conventional TEDs cannot align with the contour of our bodies for the best thermoregulation effect.Hence,we designed a kirigami-based wearable TED with excellent water vapor permeability,flexibility,and conformability.Numerical analysis and experimental results reveal that our product can withstand various types of large mechanical deformation without circuit rupture.The stated outcome and proposed facile approach not only reinforce the development of wearable TEDs but also offer an innovative opportunity for different electronics that require high conformability.
基金This work was supported by grants from the National Natural Science Foundation of China(32030013,31821001).
文摘Extending recent findings that reptile embryos seek optimal temperatures inside eggs for thermoregulation,our study demonstrates that this thermoregulatory behaviour can be affected by the amount of oxygen available to an embryo.We exposed embryos of a freshwater turtle(Mauremys reevesii)to two heat sources(an optimal temperature of 30°C and a high temperature of 33°C)under three different oxygen levels–hypoxia(12%O2),normoxia(21%O2)and hyperoxia(30%O2)–and quantified the interactive effects of temperature and oxygen availability on embryonic thermoregulatory behaviour.Our results demonstrated that,in both thermal treatments,embryos exposed to hypoxia did not move as close to the heat source and therefore selected lower temperatures than those exposed to normoxia or hyperoxia.Embryos may select low temperatures under hypoxic conditions to decrease oxygen consumption and therefore alleviate the negative impact of hypoxic stress.
文摘In the paper a new two-dimensional 'man-WCV'(water cooling vest) mathematical model is developed. This model is of practical use: it can predict transient temperature responses and body temperature distribution for a person in a nonuniform hot environment, doing various jobs and dressed in different clothes. In addition, the results calculated from the model can be used to optimize the distribution of the tube-net lined on the WCV and to evaluate an individual thermal conditioning system with cooling water. The results obtained from the model agree well with the author's experimental data.
基金Project supported by the National Basic Research Program of China(Grant No.2010CB734101)the National Natural Science Foundation of China(Grant No.51705332)
文摘A three-dimensional thermoregulation mathematical model of temperature fluctuations for the human body is developed based on predecessors＇ thermal models. The following improvements are necessary in real situations： ellipsoids and elliptical cylinders are used to adequately approximate body geometry, divided into 18 segments and five layers; the core layer consists of the organs; the pulsation of the heart cycle, the pulsatile laminar flow, the peripheral resistance, and the thermal effect of food are considered. The model is calculated by adopting computational fluid dynamics（CFD） technology, and the results of the model match with the experimental data. This paper can give a reasonable explanation for the temperature fluctuations.
文摘Metabolisms play a vital role in thermoregulation in the human body. The metabolic rate varies with the activity levels and has different behaviors in nature depending on the physical activities of the person. During the activity, metabolic rate increases rapidly at the beginning and then increases slowly to become almost constant after a certain time. So, its behavior is as logistics in nature. The high metabolic rate during activity causes the increase of body core temperature up to 39˚C <a href="#ref1">[1] <a href="#ref2">[2]. The logistic model of metabolic rate is used to re-model Pennes’ bioheat equation for the study of temperature distribution in three layered human dermal parts during carpentering, swimming and marathon. The finite element method is used to obtain the solution of the model equation. The results demonstrate that there is a significant change in tissue temperature due to sweating and ambient temperature variations.
基金supported by funding from the National Natural Science Foundation of China(Grant Nos.32030013 and 31821001)Yongpu Zhang and Shuran Li were supported by funding from the National Natural Science Foundation of China(Grant Nos.31971419 and 32171486).
文摘Dear Editor,Traditional studies on animal behavior mainly focus on the post-hatching phase of the life history,assuming that embryos are works-in-progress,despite most animals spending a significant time developing embryos inside an egg or mother's body(Du&Shine 2022).Although embryos are thought to be passive to their environment,several studies have demonstrated that behavioral thermoregulation occurs in embryonic reptiles and birds(Du et al.2011;Zhao et al.2013;Li et al.2014).Behavioral thermoregulation may enable embryos to develop at suitable temperatures,thereby increasing their developmental success(Du et al.2011).Second,behavioral thermoregulation by embryos is expected to produce hatchlings with better performance and higher fitness(Ye et al.2019;Liu et al.2023).For example,in species that exhibit temperature-dependent sex determination,behavioral thermoregulation may enable embryos to select suitable temperatures to fine-tune sexual differentiation,thereby expanding the range of nest temperatures that produce equal offspring sex ratios(Ye et al.2019).
基金supported by the Shanghai Stomatological Hospital Science and Technology Talents Project(SSH-2022-KJCX-B01)National Key Research and Development Program of China(2021YFA1201302/2021YFA1201300)+3 种基金the National Natural Science Foundation of China(NO.52173029NO.51733002NO.51803022)Guoyin Chen thanks for the support from the fellowship of China National Postdoctoral Program for Innovative Talents under Grant BX20220063,and Graduate Student Innovation Fund of Donghua University(CUSF-DH-D-2020038).
文摘With the rise of optogenetic manipulation of neurons,the effects of optogenetic heating on temperature-sensitive physi-ological processes,and the damage to surrounding tissues have been neglected.This manuscript reports the fabrication of a highly temperature-sensitive semi-interpenetrating optical hydrogel fiber(TSOHF)using the integrated dynamic wet-spinning technique.TSOHF exhibits a structural tunable diameter,clear core/sheath structure,tunable temperature-sensitivity,excellent light propagation property(0.35 dB cm^(-1),650 nm laser light),and good biocompatibility(including tissue-like Young’s modulus,stable dimensional stability,and low cytotoxicity).Based on these properties,a potential application of optogenetic regulation of neural tissue(hypoglossal nerve),with controllable temperature using TSOHF was designed and performed.Further,this work provides new insight into molecular design and a practical approach to continually manufacture a temperature-sensitive hydrogel optical fiber for applications in intelligent photomedicine.
文摘The thermoregulation behavior ofLucilia sericata larvae （Diptera： Calliphori- dae）, a necrophagous species that feeds on vertebrate cadavers, was investigated. These larvae require high heat incomes to develop, and can elevate temperatures by forming large aggregates. We hypothesized that L. sericata larvae should continue to feed at temperatures up to 38 ℃, which can be reached inside larval masses. Thermal regulation behavior such as movement between a hot food spot and colder areas was also postulated. The hypotheses were tested by tracking for 1 h the activity of single, starved third instar larvae in a Petri dish containing 1 food spot （FS） that was heated to a constant temperature of 25 ℃, 34 ℃ or 38 ℃ with an ambient temperature of 25 ℃. The influence of previous conspecific activity in the food on larval behavior was also tested. The crops of larvae were dissected to monitor food content in the digestive systems. Based on relative crop measurements, larvae fed at all food temperatures, but temperature strongly affected larval behavior and kinematics. The total time spent by larvae in FS and the duration of each stay decreased at high FS temperature. Previous activity of conspecifics in the food slightly increased the time spent by larvae in FS and also decreased the average distance to FS. Therefore, necrophagous L. sericata larvae likely thermoregulate during normal feeding activities by adjusting to local fluctuations in temperature, particularly inside maggot masses. By maintaining a steady internal body temperature, larvae likely reduce their development time.
基金Open Access funding enabled and organized by CAUL and its Member Institutions.
文摘Background Although not universal,active care is being offered to infants weighing<500 g at birth,referred to as ultra-low birth weight(ULBW)infants appropriate for gestational age.These infants have the greatest risk of dying or developing major morbidities.ULBW infants face challenges related to fluid and heat loss as well as skin injury in the initial days of life from extreme anatomical and physiological immaturity of the skin.Although there is an emerging literature on the outcomes of ULBW infants,there is a paucity of evidence to inform practice guidelines for delivering optimal care to this cohort of infants.Data sources A comprehensive review of the literature was performed using the PubMed and Embase databases.Searched keywords included“thermoregulation or body temperature regulation”,“incubator humidity”,“skin care”,“infant,extremely low birth weight”and“ultra-low birth weight infants”.Results Evidences for thermoregulation,incubator humidity,and skincare practices are available for preterm infants weighing<1500 g at birth but not specifically for ULBW infants.Studies on thermoregulation,incubator humidity,or skincare practices had a small sample size and did not include a sub-group analysis for ULBW infants.Current practice recommendations in ULBW infants are adopted from research in very and/or extremely low birth weight infants.Conclusions This narrative review focuses on challenges in thermoregulation,incubator humidity,and skincare practices in ULBW infants,highlights current research gaps and suggests potential developments for informing practices for improving health outcomes in ULBW infants.
文摘The brood-parasitic brown-headed cowbird(Molothrus ater)has one of the shortest incubation periods of any bird.Brown-headed cowbird eggs,and those of other avian brood parasites,tend to be more spherical due to their greater relative width.The traditional explanation for this egg shape is that it,combined with the thicker eggshells,resists host puncture-ejection.However,very few North American hosts of the brownheaded cowbird actually engage in puncture-ejection and therefore wider eggs may instead provide greater contact with a host’s brood patch during incubation,especially in large host nests.We tested whether greater egg width increased mean temperature and reduced temperature variation in brown-headed cowbirds by inserting temperature probes into brown-headed cowbird and house sparrow(Passer domesticus)eggs and placing them into red-winged blackbird(Agelaius phoeniceus)nests.House sparrow eggs are similar in appearance and in length to cowbird eggs,but are not as wide.We found no signifcant relationship between brown-headed cowbird egg width and mean incubation temperature.However,brown-headed cowbird eggs experienced less temperature variation than house sparrow eggs,and within brown-headed cowbird eggs,more spherical eggs experienced less temperature variation when accounting for differences in width.These results suggest that brownheaded cowbirds may have short incubation periods in part because their eggs exhibit less temperature variation over the course of incubation.The brown-headed cowbird’s egg shape may contribute to its accelerated embryonic development rate relative to host eggs of similar size,which explains its ability to hatch in a variety of host nests.
基金funded by the European Regional Development Fund(ERDF A way of making Europe)and the Spanish Ministry of Education and Science(grant CGL2008-00137/BOS).
文摘Non-signaling functions of coloration include thermoregulation(thermal melanism hypothesis),protection against ultraviolet radiation(photoprotection hypothesis),and concealment from predators(crypsis hypothesis).We investigated whether dorsal coloration in 19 populations of spiny-footed lizards,Acanthodactylus erythrurus,across the Iberian Peninsula varies according to these functions.We captured adult males and females in each population and calculated standardized dorsum brightness estimates from photographs.We also calculated standardized ground luminosity estimates and gathered information on latitude,altitude,mean annual temperature,and mean annual solar radiation for each location.Males showed a higher percentage of black coloration and a more contrasted dorsum than females,suggesting different selection pressures on dorsal coloration in both sexes.Furthermore,males showed a darker dorsum and a higher percentage of black coloration at higher altitudes and when the ground was darker.In contrast,females exhibited a darker dorsum only when the ground was darker and a higher percentage of black coloration only at higher altitudes.We also observed that the variation of dorsum luminosity within males and the variation of dorsum luminosity among females within populations were both positively related to the variation of ground luminosity among different points within locations.Latitude,temperature,and solar radiation were not signifcantly related to dorsal coloration in either sex.Our results support the photoprotection and crypsis hypotheses in males and,to some extent,in females,whereas the thermal melanism hypothesis is weakly supported in both sexes.These fndings suggest that there is local adaptation in the dorsal coloration of the spiny-footed lizard.
基金The National Natural Science Foundation of China(No.5087125)
文摘The local skin temperatures of 22 subjects at air temperatures of 21,24,26,29 ℃ are measured,and the mean skin temperatures are calculated by ten skin temperature measuring points.The thermal comfort levels and the thermal sensations of these subjects are also investigated by a questionnaire.The Mahalanobis distance discrimination method is applied to establish the evaluation model for the thermal comfort based on the mean skin temperature.The experimental results indicate that the difference of the mean skin temperatures between the comfort level and the discomfort level is significant.Using the evaluation model,the mean skin temperature at the thermal comfort level is 32.6 to 33.7 ℃,and the thermal comfort levels of 72% of the subjects are correctly evaluated.The accuracy of the evaluation model can be improved when the effects of sex of the subject on the mean skin temperature and the thermal comfort are considered.It can be concluded that the mean skin temperature can be used as an effective physiological indicator to evaluate human thermal comfort in a steady thermal environment.
文摘Growing concern about the influence of climate change on flowering plants, pollinators, and the mutualistic interac- tions between them has led to a recent surge in research. Much of this research has addressed the consequences of warming for phenological and distributional shifts. In contrast, relatively little is known about the physiological responses of plants and insect pollinators to climate warming and, in particular, how these responses might affect plant-pollinator interactions. Here, we summa- rize the direct physiological effects of temperature on flowering plants and pollinating insects to highlight ways in which plant and pollinator responses could affect floral resources for pollinators, and pollination success for plants, respectively. We also con- sider the overall effects of these responses on plant-pollinator interaction networks. Plant responses to wanning, which include altered flower, nectar, and pollen production, could modify floral resource availability and reproductive output of pollinating in- sects. Similarly, pollinator responses, such as altered foraging activity, body size, and life span, could affect patterns of pollen flow and pollination success of flowering plants. As a result, network structure could be altered as interactions are gained and lost, weakened and strengthened, even without the gain or loss of species or temporal overlap. Future research that addresses not only how plant and pollinator physiology are affected by warming but also how responses scale up to affect interactions and networks should allow us to better understand and predict the effects of climate change on this important ecosystem service .
基金supported by a Vice-Chancellors Doctoral Scholarship obtained by EA (17968962)。
文摘Acute exposure to heat, such as that experienced by people arriving into a hotter or more humid environment, can compromise physical and cognitive performance as well as health. In military contexts heat stress is exacerbated by the combination of protective clothing, carried loads, and unique activity profiles, making them susceptible to heat illnesses. As the operational environment is dynamic and unpredictable, strategies to minimize the effects of heat should be planned and conducted prior to deployment. This review explores how heat acclimation(HA) prior to deployment may attenuate the effects of heat by initiating physiological and behavioural adaptations to more efficiently and effectively protect thermal homeostasis, thereby improving performance and reducing heat illness risk. HA usually requires access to heat chamber facilities and takes weeks to conduct, which can often make it impractical and infeasible, especially if there are other training requirements and expectations. Recent research in athletic populations has produced protocols that are more feasible and accessible by reducing the time taken to induce adaptations, as well as exploring new methods such as passive HA. These protocols use shorter HA periods or minimise additional training requirements respectively, while still invoking key physiological adaptations, such as lowered core temperature, reduced heart rate and increased sweat rate at a given intensity. For deployments of special units at short notice(< 1 day) it might be optimal to use heat re-acclimation to maintain an elevated baseline of heat tolerance for long periods in anticipation of such an event. Methods practical for military groups are yet to be fully understood, therefore further investigation into the effectiveness of HA methods is required to establish the most effective and feasible approach to implement them within military groups.
基金support from the Research Grants Council of the Hong Kong Special Administrative Region,China(PolyU152052/21E)Green Tech Fund of Hong Kong(Project No.:GTF202220106)+1 种基金Innovation and Technology Fund of the Hong Kong Special Administrative Region,China(ITP/018/21TP)PolyU Endowed Young Scholars Scheme(Project No.:84CC).
文摘Maintaining thermal comfort within the human body is crucial for optimal health and overall well-being.By merely broadening the setpoint of indoor temperatures,we could significantly slash energy usage in building heating,ventilation,and air-conditioning systems.In recent years,there has been a surge in advancements in personal thermal management(PTM),aiming to regulate heat and moisture transfer within our immediate surroundings,clothing,and skin.The advent of PTM is driven by the rapid development in nano/micro-materials and energy science and engineering.An emerging research area in PTM is personal radiative thermal management(PRTM),which demonstrates immense potential with its high radiative heat transfer efficiency and ease of regulation.However,it is less taken into account in traditional textiles,and there currently lies a gap in our knowledge and understanding of PRTM.In this review,we aim to present a thorough analysis of advanced textile materials and technologies for PRTM.Specifically,we will introduce and discuss the underlying radiation heat transfer mechanisms,fabrication methods of textiles,and various indoor/outdoor applications in light of their different regulation functionalities,including radiative cooling,radiative heating,and dual-mode thermoregulation.Furthermore,we will shine a light on the current hurdles,propose potential strategies,and delve into future technology trends for PRTM with an emphasis on functionalities and applications.
基金financially supported by the Green Science program funded by POSCOthe National Research Foundation(NRF)grants(NRF2019R1A2C3003129,CAMM-2019M3A6B3030637,NRF-2019R1A5A8080290,and NRF-2018M3D1A1058997)funded by the Ministry of Science and ICT,Republic of Korea+2 种基金the Global Ph.D.fellowship(NRF-2017H1A2A1043204)from the Ministry of Education,Republic of Koreathe PIURI fellowship funded by POSTECHa fellowship from Hyundai Motor Chung Mong-Koo Foundation。
文摘This paper presents design and simulation of a switchable radiative cooler that exploits phase transition in vanadium di-oxide to turn on and off in response to temperature.The cooler consists of an emitter and a solar reflector separated by a spacer.The emitter and the reflector play a role of emitting energy in mid-infrared and blocking incoming solar energy in ultraviolet to near-infrared regime,respectively.Because of the phase transition of doped vanadium dioxide at room tem-perature,the emitter radiates its thermal energy only when the temperature is above the phase transition temperature.The feasibility of cooling is simulated using real outdoor conditions.We confirme that the switchable cooler can keep a desired temperature,despite change in environmental conditions.
文摘The big-headed turtle Platysternon megacephalum is a stream-dwelling species whose ecology is poorly known. We carried out field and laboratory investigations to determine field body temperatures and thermal preference of this species. In the field, the body temperatures of the turtles conformed to the water temperature, with little diel variation in either summer or au- tumn. Over the diel cycle, the mean body temperatures ranged from 20.8℃ to 22.2℃ in summer and from 19.3℃ to 21.2℃ in autumn; the highest body temperatures ranged from 22.1℃ to 25.0℃ in summer and from 20.6℃ to 23.8℃ in autumn. In the laboratory, the preferred body temperature （Tp） was 25.3℃ Food intake was maximized at 24.0℃, whereas locomotor perfor- mance peaked at 30.0℃. Consequently, Tp was closer to the thermal optimum for food intake than for locomotion. Therefore, this freshwater turtle has relative low field body temperatures corresponding to its thermal environment. In addition, the turtle prefers low temperatures and has a low optimal temperature for food intake [Current Zoology 59 （5）： 626-632, 20＇13].
文摘Purpose: The purpose of this study was to examine the effects of pre-cooling and fluid replacement with either crushed ice or cold water.Methods: On 2 separate occasions, in a counterbalanced order, 9 recreationally-trained males ingested 1.25 g/kg(80–100 g) of either crushed ice(0.5℃)or cold water(4℃) every 5 min for 30 min before exercise. They also ingested 2.0 g/kg(130–160 g) of the same treatment drink at 15 min, 30 min, and45 min after the commencement of cycling to exhaustion at 60%VO_(2max) until voluntary exhaustion in a hot environment(35℃ and 30% relative humidity).Results: The cycling time to exhaustion in the crushed ice trial(50.0 ± 12.2 min) was longer than the cold water trial(42.2 ± 10.1 min; p = 0.02).Although the rectal temperature fell by 0.37℃± 0.03℃(p = 0.01) at the end of the resting period after the crushed ice ingestion, the rates of rise in rectal temperature during the exercise period were not significantly different between these 2 conditions(crushed ice: 0.23℃± 0.07℃, 5 min;cold water: 0.22℃± 0.07℃, 5 min; p = 0.94).Conclusion: Crushed ice ingestion before and during exercise in a hot environment may be a preferred and effective approach for minimizing thermal strain, and for improving endurance performance as compared with cold water ingestion.
基金the National Key Research and Development Program of China(2022YFB3805800)the National Natural Science Foundation of China(52173059 and U21A2095)+2 种基金the Postgraduate Research and Practice Innovation Program of Jiangsu Province(KYCX223203)the Major Basic Research Project of the Natural Science Foundation of the Jiangsu Higher Education Institutions(21KJA540002)the Key Research and Development Program of Hubei Province(2021BAA068).
文摘Chemical resistant textiles are vital for safeguarding humans against chemical hazards in various settings.such as industrialproduction,chemicalaccidents,laboratory activities,and road transportation.However,the ideal integration of chemical resistance,thermal and moisture management,and wearer condition monitoring in conventional chemically protective textiles remains challenging.Herein,the design,manufacturing,and use of stretchable hierarchical core-shell yarns(HCSYs)for integrated chemical resistance,moisture regulation,and smart sensing textiles are demonstrated.These yarns con-tain helically elastic spandex,wrapped silver-plated nylon,and surface-structuredpolytetrafluo-roethylene(PTFE)yarns and are designed and manufactured based on a scalable fabrication process.In addition to their ideal chemical resistance performance,HCSYs can function as multifunctional stretch-able electronics for real-time human motion monitoring and as the basic element of intelligent textiles.Furthermore,a desirable dynamic thermoregulation function is achieved by exploiting the fabric structure with stretching modulation.Our HCSYs may provide prospective opportunities for the future development of smart protective textiles with high durability,flexibility,and scalability.
