Warm Environment Research Articles

Modeling local thermal responses of individuals: Validation of advanced human thermo-physiology models

Human thermo-physiology models (HTPM) are useful tools to assess dynamic and non-uniform human thermal states. However, they are developed based on the physiological data of an average person. In this paper, we present a detailed evaluation of two sophisticated and well-known models, JOS3 and ThermoSEM, with the objective to evaluate their capabilities in predicting the local skin temperature of individual people as both models use individual parameters such as sex, height, weight, and fat percentage as input. For the purpose of validation, controlled experiments were conducted with six human subjects (3 males, 3 females) at different environmental conditions (22–28 °C). The measured core temperature and the local skin temperature at 14 locations were used to evaluate the predicted values. Outputs from both HTPMs followed the dynamic trend of the experiments, with a root mean squared error (RMSE) of 0.9–0.3 °C for core temperature and 1.3–0.9 °C for mean skin temperature from both ThermoSEM and JOS3 correspondingly. However, the main errors came from the body extremities. The RMSE was different for each subject, and both models showed lower errors in the warmer environment. The average RMSE for the hands of all subjects was 2 °C from ThermoSEM and 1.9 °C from JOS3, while it was 0.8 °C for the forehead in both models. The paper highlights the capabilities and limitations of the selected HTPMs and, furthermore, discusses the application of HTPMs in the field of personalized thermal comfort.

Hot and Cold: Photochemical Weathering Mediates Oil Properties and Fate Differently Depending on Seawater Temperature.

Photochemical weathering transforms petroleum oil and changes its bulk physical properties, as well as its partitioning into seawater. This transformation process is likely to occur in a cold water marine oil spill, but little is known about the behavior of photochemically weathered oil in cold water. We quantified the effect of photochemical weathering on oil properties and partitioning across temperatures. Compared to weathering in the dark, photochemical weathering increases oil viscosity and water-soluble content, decreases oil-seawater interfacial tension, and slightly increases density. Many of these photochemical changes are much larger than changes caused by evaporative weathering. Further, the viscosity and water-soluble content of photochemically weathered oil are more temperature-sensitive compared to evaporatively weathered oil, which changes the importance of key fate processes in warm versus cold environments. Compared to at 30 °C, photochemically weathered oil at 5 °C would have a 16× higher viscosity and a 7× lower water-soluble content, resulting in lower entrainment and dissolution. Collectively, the physical properties and thus fate of photochemically weathered oil in a cold water spill may be substantially different from those in a warm water spill. These differences could affect the choice of oil spill response options in cold, high-light environments.

Amphibian larvae benefit from a warm environment under simultaneous threat from chytridiomycosis and ranavirosis

Rising temperatures can facilitate epizootic outbreaks, but disease outbreaks may be suppressed if temperatures increase beyond the optimum of the pathogens while still within the temperature range that allows for effective immune function in hosts. The two most devastating pathogens of wild amphibians, Batrachochytrium dendrobatidis (Bd) and ranaviruses (Rv), co‐occur in large areas, yet little is known about the consequences of their co‐infection and how these consequences depend on temperature. Here we tested how exposure to Bd and subsequent exposure to Rv, followed by treatment at elevated temperatures (28 and 30°C versus 22°C) affected Bd and Rv prevalence, infection intensities, and resulting mortalities in larval agile frogs and common toads. We found multiple pieces of evidence that the presence of one pathogen influenced the prevalence and/or infection intensity of the other pathogen in both species, depending on temperature and initial Rv concentration. Generally, the 30°C treatment lowered the prevalence and infection intensity of both pathogens and, in agile frogs, this was mirrored by higher survival. These results suggest that if temperatures naturally increase or are artificially elevated beyond what is ideal for both Bd and Rv, amphibians may be able to control infections and survive even the simultaneous presence of their most dangerous pathogenic enemies.

GEOGRAPHIC DISTRIBUTION AND ENVIRONMENTAL SETTING OF CLAVULINA PSEUDOPARISENSIS ANAN AROUND THE ARABIAN PENINSULA

The recent agglutinated small benthic foraminiferal species Clavulina pseudoparisensis Anan are common in the five coastal areas around the Arabian Peninsula: the Egyptian Red Sea coast between Qusseir-Marsa Alam, the Saudi Arabian Red Sea coast in Jeddah, the north Socotra Island of Yemen, the Abu Dhabi coast of the United Arab Emirates (UAE), and the east coast of Qatar of the Arabian Gulf. The taxonomy is presented and discussed. The warmer environment of the Red Sea, and also the other studied areas, favor precipitation of organic binding material for the sand grains of the arenaceous tests, which favor the forms thriving in shallow and warm environment. The recorded C. pseudoparisensis in wide geographic distribution in the Red Sea, Arabian Sea, and Arabian Gulf around the Arabian Peninsula indicates an open marine environment between these localities.

Variability of asymbiotic N‐fixation organism activity with distance and time in North Dakota transitional no‐till soils

AbstractAsymbiotic nitrogen fixation (N‐fixation) is a microbial process that may result in the introduction of plant‐available N into the soil. Although the process of N mineralization in soils is mediated by many microorganisms and is related mostly to soil moisture, the soil factors which regulate asymbiotic N‐fixation are relatively unknown and the number of microorganisms with the ability to fix N is small relative to the whole soil microorganism pool. Soils under long‐term no‐till management have greater asymbiotic N‐fixing organism activity compared to no‐till. This study was conducted to determine the variance of N‐fixing activity over distance, and the temporal variability of asymbiotic N‐fixing organism activity at six sites with transitional no‐till soils in eastern North Dakota over three growing seasons. Sites were sampled at the same location each month of the growing season from 2019 to 2021. At one of the sampling dates, each year additional samples were obtained at distances from the central sampling location for use in statistical analysis. The sampling over distance indicated that to characterize a large field area, multiple samples should be taken and analyzed separately or mixed together for single analysis. Monthly sampling in all 3 years indicated that peak N‐fixation activity was favored by a moist, warm environment. Dry periods and excessively wet periods resulted in low activity. Heavy rains within 48 h of sampling resulted in extremely low N‐fixation activity at the subsequent sampling date. Models were constructed relating the accumulative rainfall from the 30 days prior to sampling, and the mean air temperature from the 30 days prior to sampling. These data indicate that the activity of asymbiotic N‐fixing organisms increased with temperature and cumulative rainfall prior to measurement.

Hempcrete as a substrate for fungal growth under high humidity and variable temperature conditions

Bio-based alternatives for existing construction materials can be used to reduce the carbon footprint of the built environment. Hempcrete is one of these materials and is both an excellent hygric/thermal regulator and is carbon negative. However, this novel material is still incompletely researched, especially its fungal growth potential specifically within warm and humid environments. The incorporation of significant biological material within hempcrete can enable it to act as a microbial growth medium, with the corresponding potential for the release of bioaerosols. The aim of this research was thus to investigate the overall practicality of hempcrete implementation in a humid climate. To achieve this, the endogenous fungal genera on a sample of hempcrete were identified, fungal propagules aerosolized from a hempcrete sample enumerated, and a range of temperatures tested to determine their effect on fungi growth determined. Trials were performed to determine whether hempcrete can be effectively decontaminated with common materials to manage microbial growth. Under high humidity, fungal propagule emissions were high with low diversity, with potentially allergenic fungi detected. Disinfection of high fungal load hempcrete samples was able to reduce ∼94% of the fungal observations and reduce aerosolized counts to average background tropical fungal counts. The range of temperatures tested were not found to effect fungal growth, contrary to the consensus of the literature. Overall, these properties make hempcrete suited to humid areas, however, further research to investigate the potential effects of fungi on the material remains lacking.

Effect of change rates and directions of air temperature ramps on thermal responses of occupants under warm summer conditions

Understanding thermal comfort in dynamic environments is vital for developing various air temperature control strategies that consider energy flexibility. However, studies on the quantitative effects of air-temperature change rates and directions on human thermal responses in thermal environments with temperature ramps (TRs) are limited. In this study, 22 sex-balanced young adults were recruited to investigate the thermal perceptions and physiological responses to room air TRs at rates of 0.10–0.30 °C/min in a climate chamber. The results revealed that the air temperature change direction had no effect on the mean skin temperature (Tskin) but significantly affected the thermal sensation vote (TSV), that is, the TSV was approximately 0.5 scales lower when the temperature was decreasing than when it was increasing (P < 0.05). Moreover, the slow change rates of Tskin within the range of ±0.07 °C/min had no significant effect on dynamic TSV, unlike that in step-change environments with higher change rates. The head was the most thermally sensitive body part with the highest TSV/Tskin values and change rates of Tskin (up to ±0.08 °C/min) in warm TR environments. In most cases, the thermal response of limbs was delayed. The thermal experience and adaptation levels of occupants may play essential roles in thermal perceptions within TR environments. Preliminary thermal comfort models suitable for hot summer climates were proposed in this study, which could be used in TR control strategies, such as intermittent cooling or demand response control.

Effects of boundary layer dynamics and meteorology on ultrafine particle formation and growth

It is currently not well understood how the planetary boundary layer (PBL) dynamics affects the formation and growth of ultrafine particles in the atmosphere, because of the limited co-located aerosol size distributions and lidar measurements. Here we show, from long-term in-situ observations, a clear link between boundary layer processes and surface aerosol dynamics. Aerosol size distributions in the diameter range from 7 to 300 nm were measured with a scanning mobility particle sizer (SMPS) at the University of Alabama Huntsville campus in 2016, 2017, and 2022. The backscatter of larger aerosols was measured using a co-located lidar ceilometer. Meteorological surface parameters including temperature, relative humidity, station pressure, wind speed and direction, solar radiation, and precipitation were also measured. New particle formation (NPF) and long growth (over 12 h) events occurred most frequently during the winter, unlike many other locations where NPF events occur more frequently in spring and fall, indicating that cooler temperatures play important roles in ultrafine particle formation in the warm subtropical environment. During the summer with strong solar radiation, there were more short-time growth events (less than 6 h), likely associated with convection within the boundary layer. Our observations also show cold fronts affect the measured aerosol size distributions because the combination of precipitation scavenging and cleaner air can provide thermodynamic conditions favorable for NPF and aerosol growth. These results highlight the importance of meteorology on aerosol formation and growth.

Differences in thermal energetics of the cave myotis (Myotis velifer) from a cool and a warm environment of central Mexico

Endotherm homeotherms deal with the energetic cost of maintaining a stable body temperature ( Tb) in ecosystems differing in ambient temperature ( Ta). In response, animals adjust some of their thermal energetics to meet the energy requirements of thermoregulation. Bats are small mammals with a geographical distribution that may include environments with different Ta. Therefore, these animals should adjust their thermal energetics depending on the environmental characteristics of the habitats where they live. Using open-flow respirometry, we measured basal metabolic rate (BMR), thermal conductance ( C’), lower and upper critical temperatures ( TLC and TUC), and breadth of the thermoneutral zone (TNZb) of the cave myotis ( Myotis velifer (J.A. Allen, 1890)) living in a coniferous forest versus a tropical deciduous forest in central Mexico. To our knowledge, this is the first attempt to measure thermal energetics at the intraspecific level in populations measured at the same time. Bats from the coniferous forest had lower BMR, C’, TLC, TUC, and a wider TNZb than bats from the tropical deciduous forest. The results we found here are likely the consequence of the differences between the energy demands imposed by Ta, where the animals roost, and the Ta and prey availability of their foraging areas. These differences may help individuals regulate their heat production and dissipation to maintain low thermoregulatory costs in the places they inhabit.

Pre‐adaptation and adaptation shape trait‐environment matching in the Neotropics

AbstractAimFunctional traits shape the distribution of taxa across environments. However, it remains unclear whether trait and environmental niche evolution are correlated, and what happened first: trait change facilitating environment shifts (pre‐adaptation) or environmental change leading to trait change (adaptation). We focus on a species‐rich Neotropical legume radiation to shed light on this enigma.LocationNeotropics.Time PeriodCenozoic.Major Taxa StudiedFabaceae: Papilionoidae: Swartzia.MethodsWe assembled leaflet, fruit and petal size data from monographs and herbarium collections for 86 to 96% of the c. 180 Swartzia species, inferred a dated Swartzia phylogenetic tree from existing DNA sequences covering 38% of the species and integrated these with distribution, soil and climate data. We used phylogenetic linear regression to quantify trait–environment relationships and applied comparative methods to evaluate modes of correlated evolution between traits and environments.ResultsLeaflet and petal size were strongly linked to climate, while fruit size was not associated with climate or soil characteristics. Evolutionary transitions to relatively low rainfall and low temperature environments were conditional on the evolution of small leaflets, whereas transitions to wet and warm environments were preceded by the evolution of larger leaflets. In contrast, transitions to the warmest or coldest environments were followed, rather than preceded, by petal loss.Main ConclusionOur results show that the macroevolution of functional traits has influenced the broad‐scale distribution of Swartzia across Neotropical rainforest, seasonally dry, montane and inundated habitats. We suggest that trait evolution is conditional on environmental change but both pre‐adaptive and adaptive processes may occur. These processes are important to understand the distribution of diversity at both regional (e.g. Amazonia) and global biogeographical scales.

Experimental warming altered plant functional traits and their coordination in a permafrost ecosystem.

Knowledge about changes in plant functional traits is valuable for the mechanistic understanding of warming effects on ecosystem functions. However, observations have tended to focus on aboveground plant traits, and there is little information about changes in belowground plant traits or the coordination of above- and belowground traits under climate warming, particularly in permafrost ecosystems. Based on a 7-yr field warming experiment, we measured 26 above- and belowground plant traits of four dominant species, and explored community functional composition and trait networks in response to experimental warming in a permafrost ecosystem on the Tibetan Plateau. Experimental warming shifted community-level functional traits toward more acquisitive values, with earlier green-up, greater plant height, larger leaves, higher photosynthetic resource-use efficiency, thinner roots, and greater specific root length and root nutrient concentrations. However, warming had a negligible effect in terms of functional diversity. In addition, warming shifted hub traits which have the highest centrality in the network from specific root area to leaf area. These results demonstrate that above- and belowground traits exhibit consistent adaptive strategies, with more acquisitive traits in warmer environments. Such changes could provide an adaptive advantage for plants in response to environmental change.

Impermeable Graphene Skin Increases the Heating Efficiency and Stability of an MXene Heating Element.

A Joule heater made of emerging 2D nanosheets, i.e., MXene, has the advantage of low-voltage operation with stable heat generation owing to its highly conductive and uniformly layered structure. However, the self-heated MXene sheets easily get oxidized in warm and moist environments, which limits their intrinsic heating efficiencies. Herein, an ultrathin graphene skin is introduced as a surface-regulative coating on MXene to enhance its oxidative stability and Joule heating efficiency. The skin layer is deposited on MXene using a scalable solution-phased layer-by-layer assembly process without deteriorating the excellent electrical conductivity of the MXene. The graphene skin comprises narrow and hydrophobic channels, which results in ≈70 times higher water impermeability of the hybrid film of graphene and MXene (GMX) than that of the pristine MXene. A complementary electrochemical analysis confirms that the graphene skin facilitates longer-lasting protection than conventional polymer coatings owing to its tortuous pathways. In addition, the sp2 planar carbon surface with a low heat loss coefficient improves the heating efficiency of the GMX, indicating that this strategy is promising for developing adaptive heating materials with a tractable voltage range and high Joule heating efficiency.

The Way of Water: ALMA Resolves H2O Emission Lines in a Strongly Lensed Dusty Star-forming Galaxy at z ∼ 3.1

We report Atacama Large Millimeter/submillimeter Array (ALMA) high-resolution (≲0.3″) observations of water emission lines p-H2O(202 − 111), o-H2O(321 − 312), p-H2O(422 − 413), in the strongly lensed galaxy HATLASJ113526.2-01460 at redshift z ∼3.1. From the lensing-reconstructed maps of water emission and line profiles, we infer the general physical properties of the interstellar medium (ISM) in the molecular clouds where the lines arise. We find that the water vapor lines o-H2O(321 − 312), p-H2O(422 − 413) are mainly excited by far-infrared (FIR) pumping from dust radiation in a warm and dense environment, with dust temperatures ranging from 70 to ∼100 K, as suggested by the line ratios. The p-H2O(202 − 111) line, instead, is excited by a complex interplay between FIR pumping and collisional excitation in the dense core of the star-forming region. This scenario is also supported by the detection of the medium-level excitation of CO resulting in the line emission CO (J = 8–7). Thanks to the unprecedented high resolution offered by the combination of ALMA capabilities and gravitational lensing, we discern the different phases of the ISM and locate the hot molecular clouds into a physical scale of ∼500 pc. We discuss the possibility of J1135 hosting an active galactic nucleus in its accretion phase. Finally, we determine the relation between the water emission lines and the total IR luminosity of J1135, as well as the star formation rate as a function of water emission intensities, comparing the outcomes to local and high-z galactic samples from the literature.

Formulating a Blue Ocean Strategy to Revitalize the Hotel Industry: The Case of the Residence Hotel Industry in Korea

Purpose – The purpose of this study was to provide a systematic technique for building a blue ocean strategy for residence hotels using research methodologies on customer satisfaction aspects in marketing on a strategic canvas and an ERRC matrix. Design/Methodology/Approach – To do this, we conducted a survey among hotel visitors using questionnaire items and a self-administered data collection approach, with each item scored on a 5-point scale. Judgment sampling was utilized as the sample method. We then used the survey responses to generate an ERRC matrix using IPA analysis. Findings – According to the ERRC table, hotel attributes that fall under the Raise category include “cleanliness of rooms”, “hotel location”, and “cultural and convenience facilities around the hotel”. Hotel attributes in the Reduce category include “diversity of food and beverage outlets” and “interior decoration and design”, whereas hotel attributes in the Create category include “cultural events”, “creating cultural streets”, and “a family-friendly atmosphere”. The use of the survey results-based Blue Ocean Strategy in the formulation of innovation strategies can provide managers evaluating creative strategies and strategic generating approaches with objective and detailed suggestions. Research Implications – In the Create category, hotel attributes include “cultural events”, “creating cultural streets”, and “a family-friendly atmosphere”. This indicates that, in order to attract and maintain clients, residence hotels might separate themselves from other hotels by generating demand through the development of local cultural streets. Above all, it is vital to sell not only hotel rooms but also a warm and cozy environment reminiscent of a home.

Effect of phase change cooling vest on related thermal regulation factors in moderately hot environments

Phase change cooling vests (CV) are mostly developed to improve people's thermal comfort in warm or hot environments. In this paper, the effect of a CV on related thermal regulation factor was studied. Physiological parameters (including skin temperature, sweat rate, fingertip blood flow, and ear canal temperature) and conductive heat flux were measured in three air temperature conditions (27, 29, and 31 °C). Results found that compared with no cooling vest (NCV) conditions, the maximum decrement in local skin temperature for the back and chest with CV was 2.5 and 2.1 °C, and for the mean skin temperature (Tmsk), the decrement was 0.8 °C. Simultaneously, the mean conductive heat flux of the back and chest with CV was significantly increased by 28.3% and 234.4%, respectively (p < 0.01). The total sweat rate (SR) of subjects using CV was decreased by 14%–18%. The SR of the forehead was positively correlated with the overall thermal sensation and comfort. With the use of CV, the fingertip blood flow (Qfinger) tended to decrease. As the experimental temperature elevated, the impact of the CV on Qfinger was more effective. However, there was no difference in Qfinger and ear canal temperature between the CV and NCV conditions. The results provided a better understanding of the improving effect of CV on human thermal comfort from the perspective of thermal regulation.

Radial Growth–Climate Relationship Varies with Spatial Distribution of Schima superba Stands in Southeast China’s Subtropical Forests

To understand the impact of climate change on the tree radial growth in Southeast China’s subtropical evergreen broadleaved forest, comparative research on the radial growth–climate associations of Schima superba was conducted. This dominant evergreen broadleaved tree species was examined at both its southern and northern distribution margins through dendroclimatology. The results showed that the radial growth of S. superba stands at a high elevation in the southern margin and stands in the northern margin were positively correlated with springtime temperatures, mostly in April (e.g., mean temperature: r = 0.630, p &lt; 0.05) and May (e.g., maximum temperature: r = 0.335, p &lt; 0.05), respectively. Meanwhile, the temperature in the late rainy season had a significant negative effect on the radial growth of S. superba stands in the southern margin, including high-elevation stands (e.g., the mean temperature in previous and current September: r = −0.437 and −0.383, p &lt; 0.05) and low-elevation stands (e.g., the mean temperature in previous August and October: r = −0.577 and −0.348, p &lt; 0.05). It was shown that temperature was the key climatic factor affecting the radial growth of S. superba, and the response of radial growth to temperature had obvious spatial differences. The findings indicate that the radial growth of S. superba stands in warm growth environments will be negatively impacted by future climate warming. On the contrary, the radial growth of S. superba stands growing in relatively cold growth environments may benefit from warmer spring. The results enhance the understanding of tree growth responses to climate change in the subtropical forests of China.

Dense Molecular Environments of B[e] Supergiants and Yellow Hypergiants

Massive stars expel large amounts of mass during their late evolutionary phases. We aim to unveil the physical conditions within the warm molecular environments of B[e] supergiants (B[e]SGs) and yellow hypergiants (YHGs), which are known to be embedded in circumstellar shells and disks. We present K-band spectra of two B[e]SGs from the Large Magellanic Cloud and four Galactic YHGs. The CO band emission detected from the B[e]SGs LHA 120-S 12 and LHA 120-S 134 suggests that these stars are surrounded by stable rotating molecular rings. The spectra of the YHGs display a rather diverse appearance. The objects 6 Cas and V509 Cas lack any molecular features. The star [FMR2006] 15 displays blue-shifted CO bands in emission, which might be explained by a possible close to pole-on oriented bipolar outflow. In contrast, HD 179821 shows blue-shifted CO bands in absorption. While the star itself is too hot to form molecules in its outer atmosphere, we propose that it might have experienced a recent outburst. We speculate that we currently can only see the approaching part of the expelled matter because the star itself might still block the receding parts of a (possibly) expanding gas shell.

Slow and population specific evolutionary response to a warming environment

Adaptation to increasingly warmer environments may be critical to avoid extinction. Whether and how these adaptive responses can arise is under debate. Though several studies have tackled evolutionary responses under different thermal selective regimes, very few have specifically addressed the underlying patterns of thermal adaptation under scenarios of progressive warming conditions. Also, considering how much past history affects such evolutionary response is critical. Here, we report a long-term experimental evolution study addressing the adaptive response of Drosophila subobscura populations with distinct biogeographical history to two thermal regimes. Our results showed clear differences between the historically differentiated populations, with adaptation to the warming conditions only evident in the low latitude populations. Furthermore, this adaptation was only detected after more than 30 generations of thermal evolution. Our findings show some evolutionary potential of Drosophila populations to respond to a warming environment, but the response was slow and population specific, emphasizing limitations to the ability of ectotherms to adapt to rapid thermal shifts.

Sex and population differences underlie variation in reproductive success in a warming environment.

Current rising temperatures are threatening biodiversity. It is therefore crucial to understand how climate change impacts male and female fertility and whether evolutionary responses can help in coping with heat stress. We use experimental evolution to study male and female fertility during the real-time evolution of two historically differentiated populations of Drosophila subobscura under different thermal selection regimes for 23 generations. We aim to (a) tease apart sex-specific differences in fertility after exposure to warming conditions during development, (b) test whether thermal selection can enhance fertility under thermal stress, and (c) address the role of historically distinct genetic backgrounds. Contrary to expectations, heat stress during development had a higher negative impact on female fertility than on male fertility. We did not find clear evidence for enhanced fertility in males or females evolving under warming conditions. Population history had a clear impact on fertility response under thermal stress, particularly in males with those from lower latitude presenting better performance than their higher latitude counterparts. We show that the impact of thermal stress on fertility varies between traits, sexes, and genetic backgrounds. Incorporating these several levels of variation is crucial for a deeper understanding of how fertility evolves under climate change.

Encouraging (Nudging) People to Increase Their Fluid Intake.

This narrative historical review considers the various routes to nudging consumers towards drinking more, given self-reported evidence that many people are often not adequately hydrated. This review builds on the related notion of 'visual hunger'. Interestingly, however, while many desirable foods are associated with distinctive sensory qualities (such as an appetizing smell), that may capture the consumer's (visual) attention, it is less clear that there is an equivalent sensory attentional capture by hydration-related cues. One of the other important differences between satiety and thirst is that people tend to overconsume if they use interoceptive satiety cues to decide when to stop eating, while the evidence suggests that people typically stop drinking prior to being adequately hydrated. What is more, the increasing amount of time we spend in consistently warm indoor environments may also be exacerbating our need to drink more. A number of concrete suggestions are made concerning how people may be encouraged (or nudged) to imbibe sufficient water.