Cooling agents (chemicals added to impart a cooling sensation) in tobacco products are receiving increased attention due to their use as menthol substitutes. However, detailed information on their chemical structures, physico-chemical properties, cooling activity, and human and ecotoxicity potential has not been compiled. Our goal was to profile cooling agents that could be used as menthol substitutes in tobacco products, along with descriptions of their cooling properties and estimated toxicological effects. First, we compiled a library of 228 cooling agents, including 180 unique two-dimensional (2-D) chemical structures based on a review of multiple public data sources (literature, invention patents, and public databases). The library includes chemicals with a "cool" and/or "mint" flavor profile as designated by the Flavor and Extract Manufacturers Association (FEMA), chemicals reported to activate the cation channel transient receptor potential melastatin 8 (TRPM8) receptor, and/or chemicals with reported subjective perceived sensory cooling. Second, we classified the cooling agents into three main chemical skeletons using similar structural motifs and estimated their physico-chemical properties related to cooling attributes using Schrödinger Canvas software, including log octanol-water partition coefficient (LogKow), vapor pressure, and electrotopological state index. Third, to investigate the cooling agents' similarity to each other and to menthol, we applied an unsupervised machine learning algorithm (Knowledge Discovery by Accuracy Maximization [KODAMA]) and hierarchical clustering techniques and identified six clusters. Fourth, we compiled available perceived cooling intensity data. Fifth, we used models based on experimental and predicted data (EPA's web-based Hazard Comparison Module [HCM]) to estimate human health toxicity and ecotoxicity. Some cooling agents are associated with genotoxicity, developmental toxicity, skin irritation, and eye irritation, and pose toxicity to fish, algae, and invertebrates. Using this surveillance approach will help inform future tobacco regulatory decisions and policies by profiling chemicals used as cooling agents in tobacco products and those that pose potential health hazard concerns.
Soccer is an intermittent sport requiring rapid recovery from repeated high-intensity efforts, especially under heat stress conditions. Cooling vests have emerged as a practical strategy to enhance post-exercise heat dissipation, yet their physiological effects remain underexplored. This study aimed to assess the efficacy of a cooling vest following a repeated shuttle sprint ability (RSSA) test under hot conditions, focusing on skin temperature, blood lactate, and heart rate responses. Eleven recreational male soccer players completed two RSSA tests in a randomized crossover design, each followed by 15 min of passive recovery with or without a cooling vest. Skin temperature was measured at five anatomical sites, while blood lactate and the heart rate were recorded at baseline, pre-test, and at 0, 1, 3, 5, 10, and 15 min post-exercise. Compared with the control condition, the cooling vest intervention significantly reduced skin temperature at the 3rd and the 5th min post-exercise (3 min: dz = -1.54, 95% CI [-2.53, -0.55], p < 0.001; 5 min: dz = -0.90, 95% CI [-1.71, -0.08], p = 0.016). Transient between-condition differences were also observed for blood lactate at the 3rd and the 5th min (3 min: dz = -1.00, 95% CI [-1.95, -0.006], p = 0.022; 5 min: dz = -1.34, 95% CI [-2.36, -0.31], p = 0.003) and for the heart rate at 1 min post-exercise (dz = -0.84, 95% CI [-1.59, -0.09], p = 0.013). No consistent differences were found at other time points. The protocol showed high between-day reliability (CV = 2.47%; ICC = 0.75), supporting the validity of the observed effects. In conclusion, post-exercise use of a cooling vest after repeated sprints in the heat accelerates early superficial thermal recovery, as evidenced by reductions in skin temperature during the first minutes of recovery. Transient and isolated differences were also observed for the heart rate and blood lactate concentration; however, these effects were not sustained across the full recovery time-course. From a practical perspective, cooling vests may be useful during short recovery windows in intermittent sports, while further research is needed to determine whether broader or longer-lasting physiological benefits can be achieved.
This study evaluated the practical feasibility of the CORE sensor for noninvasive tracking of changes in estimated core body temperature (Est-Tcore) during simulated beach volleyball match-play in the heat and examined the effects of a combined cooling strategy on countermovement jump (CMJ) and T-agility performance. Eleven competitive male collegiate players completed 2 simulated match-play trials under hot outdoor conditions using a randomized crossover design. The COOL condition included precooling with an ice vest and ice slurry ingestion, followed by additional ice slurry during breaks. The CON condition replicated fluid intake without cooling. Est-Tcore and heart rate (HR) were continuously monitored, and thermal sensation, thermal comfort, and session-rating of perceived exertion were assessed. CMJ and T-agility performance were measured immediately before and after the matches. COOL attenuated the increase in Est-Tcore during warm-up and improved perceptual responses (lower thermal sensation, P < .05), while HR did not differ significantly between conditions. Postmatch CMJ and T-agility did not differ significantly between the conditions, although small-to-moderate effect sizes suggested a possible preservation of performance. The CORE sensor demonstrated practical applicability for tracking relative changes in Est-Tcore during beach volleyball match play. Combined external-internal cooling attenuated thermal strain and improved perceptual responses; however, these effects did not translate into clear benefits for explosive performance outcomes.
Controlling the motion of nanoscale objects at the quantum limit promises opportunities to test fundamental quantum physics and advances in quantum sensing. Rotational motion is of particular interest, as its nonlinear dynamics in a compact, closed configuration space provides access to phenomena such as rotational interferometry, tunnelling between angular configurations and quantum-enhanced torque sensing. A key requirement for such experiments is the capability to trap nanorotors and cool their orientation close to the two-dimensional librational quantum ground state. When rotational motion is confined in a harmonic potential, it becomes librational. Here we demonstrate that coherent scattering into a high-finesse cavity enables the ground-state cooling of two orthogonal librational modes of an optically levitated SiO2 nanoparticle. Using a laser-induced desorption loading technique, we trap and cool several dimers and trimers of silica nanospheres to their respective ground states, all within a single day. The simultaneous cooling of both librational degrees of freedom allows us to align an individual nanorotor with respect to a space-fixed axis with an angular precision better than 20 µrad-close to the quantum-mechanical zero-point fluctuations.
We consider a one-machine scheduling problem where the temperature of a job rises during processing and cools down when not being processed according to given linear heating and cooling rates. No job's temperature is allowed to rise above a given threshold, and no job's temperature can cool below 0. Another crucial property of our problem is that jobs can be preempted an arbitrary number of times, and even more, we allow that a job is processed for an infinitely small amount of time. We consider two objectives: minimize the makespan and minimize the sum of completion times. Our results are as follows. We show how to compactly represent a solution. Further, we prove that the problem of minimizing the sum of completion times can be solved in polynomial time by formulating it as a linear program and deriving a structural property. This result can be extended to hold for any number of machines. Further, we show that a minimum makespan can be found in O(n) time, even when heating and cooling rates are job-dependent.
We present a high power, high energy cryogenic Yb:yttrium aluminum garnet laser head cooled by a reversed Brayton cycle-based gaseous helium system. The temperature of the helium is roughly 120 K and, typically, to reach such temperatures, liquid nitrogen is used. By utilizing a reversed Brayton cycle in the cooling circuit, the system can reach such cryogenic temperatures using only room temperature water to cool the helium. We demonstrate cooling to the level of 120 K and measure the optical properties of the laser head to show that it is suitable for high energy, high average power laser operation.
Adipocytes throughout the body reside in distinct thermal environments. Visceral adipocytes within the body core are maintained near 37 °C, whereas those in bone marrow, subcutaneous, and dermal depots occupy cooler regions within the peripheral shell. While brown and beige adipocyte responses to cold stress are well characterized, much less is known about how white adipocytes adapt to moderately reduced temperatures below 37 °C. Our recent work revealed that cultured adipocytes exposed to 31 °C, a temperature representative of distal adipose regions, exhibit enhanced mitochondrial function, including increased substrate oxidation and ATP turnover, yet the mechanisms underlying this upregulation remain unclear. Here we show that adaptation to cool temperatures leads to a widespread decrease in protein acetylation in both undifferentiated and differentiated adipocytes, independent of nutrient status, and that this change is readily reversible upon rewarming. Subcellular fractionation and immunoblotting demonstrate that the hypoacetylation coincides with a compartment-specific enrichment of acetylated proteins within mitochondria, indicating selective remodeling of the mitochondrial acetylome. Transcriptomic and biochemical analyses reveal that these temperature-dependent changes occur without alterations in acetyltransferase or deacetylase expression, NAD⁺ concentration, or acetyl-CoA availability, suggesting regulation through alternative mechanisms affecting acetyl-CoA flux or enzyme activity. Integrative acetyl-proteomic and metabolomic profiling identifies mitochondrial enzymes, including serine hydroxymethyltransferase 2 (SHMT2) and propionyl-CoA carboxylase α (PCCA), whose acetylation correlates closely with changes in associated metabolite pools. Together, these findings establish physiologically relevant cooling as a cell-autonomous regulator of mitochondrial protein acetylation and metabolic adaptation in adipocytes.
To investigate the long-term effects of combined organic and inorganic fertilizer application on the structural stability and fertility of soil in paddy fields located in the cool northeastern region of China, a long-term fixed-site experiment was initiated in 2017. The experiments included the following five treatments: 100% conventional chemical fertilizer NPK (CK), conventional PK fertilizer without N fertilizer (T1), 30% organic N and 70% chemical N fertilizers with conventional PK fertilizer (T2), 50% organic N and 50% chemical N fertilizers with conventional PK fertilizer (T3), and 100% organic N fertilizer (T4). Notably, the total amount of fertilizer applied remained consistent across treatment groups. The results revealed that the combination of organic and inorganic fertilizers significantly increased rice yields and nitrogen use efficiency, with the T3 treatment performing the best. Compared with CK, T3 resulted in a 24.26% greater rice yield, and it increased the nitrogen agronomic efficiency by 71.05%. There were no significant differences among the treatment groups in terms of the proportions of soil aggregates larger than 2 mm or smaller than 0.053 mm. Nitrogen fertilizer application reduced the proportion of 0.053-0.25 mm aggregates and promoted the formation of predominantly 0.25-2 mm aggregates. However, the different organic-inorganic combinations did not cause significant differences in soil aggregate structure or stability. Compared with the CK treatment, the application of both organic and inorganic fertilizers increased soil organic matter content, decreased N2O emissions, and increased soil catalase activity. In summary, the application of 50% organic N and 50% chemical N fertilizers with conventional PK fertilizer (T3) was determined to be the optimal combination for achieving high and stable rice yields in the cool northeastern region of China while increasing the structural stability and fertility of the soil.
A series of Na₂CaP₂O₇: xDy3+ (x = 0.01-0.06) (abbreviated as NCPO) phosphors were synthesized using the solid-state reaction method in the present research work. X-ray diffraction (XRD) was used to confirm the phase purity and crystallinity of the synthesized phosphors. Morphological and elemental analyses were carried out using field emission scanning electron microscopy (FESEM) and energy-dispersive spectroscopy (EDS), respectively. Fourier transform infrared (FT-IR) spectroscopy assessed the functional groups, while diffuse reflectance spectroscopy (DRS) was employed to estimate the optical band gap. Photoluminescence (PL) spectroscopy was performed at an excitation wavelength of 351 nm to investigate the luminescence properties of the prepared phosphors. Two emission bands were subsequently observed at 485 nm and 575 nm, corresponding to 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 transitions, respectively. The critical distance (Rc) between Dy³⁺ ions in this host was calculated to be 17 Å, indicating that both nearest-neighbor ion interactions and dipole-dipole interactions were involved. The PL decay lifetime and internal quantum efficiency (IQE) of the synthesized phosphor are determined. Photometric studies reveal that the CIE coordinates fall very close to the white light region, and the CCT value is found to be greater than 5000 K, indicating that the prepared NCPO: Dy³⁺ phosphor is a promising candidate for cool WLEDs for outdoor lighting applications.
Single-molecule white-light emitters have attracted much attention due to their potential applications in white organic light-emitting diodes (WOLEDs). Their key advantage lies in the ability to use a simple device structure, akin to that of monochromatic OLEDs, to produce WOLEDs. This approach not only simplifies the fabrication process but also reduces costs, improves device stability, and provides a shortcut for the rapid commercialization of WOLEDs. In this study, two novel single-molecule white-light emitters, SRFR-1PTZ (10-(4'-(9H-9,9'-spirobi[fluoren]-2-yl)-4a,10a-dihydro-10H-phenothiazine) and SRFR-2PTZ (2,7-bis(4a,10a-dihydro-10H-phenothiazin-10-yl)-9,9'-spirobi[fluorene]), were designed and synthesized, and successfully implemented in WOLED devices. Comprehensive photophysical characterization revealed that both compounds exhibited dual-emission characteristics in dichloromethane solution, displaying simultaneous fluorescence and phosphorescence. Notably, thermally activated delayed fluorescence (TADF) was clearly observed for SRFR-1PTZ, whereas SRFR-2PTZ did not exhibit TADF behavior. Electroluminescence studies demonstrated that both SRFR-1PTZ and SRFR-2PTZ served as good color-stable cool-white-light emitters under driving voltages of 7-10 V.
Entomopathogenic fungi (EPF) such as Metarhizium anisopliae and Beauveria bassiana are well-known biological control agents of soil-dwelling insects worldwide. Moreover, there is growing interest in applying EPF as seed treatments to serve as biostimulants for improving plant growth and stress tolerance. In this study, we examined the effects of M. anisopliae (ESF-1) and B. bassiana (GHA) seed treatments on the growth and development of turfgrasses (Lolium arundinaceum (syn. Festuca arundinacea) and Poa pratensis) in growth chamber, greenhouse, and field experiments, and also tested whether the seed treatments were a viable method of introducing EPF into the soil to increase insect suppression following soil contact using Galleria mellonella as a model. We found that EPF applied as dry powder seed treatments had overall positive or neutral effects on turfgrass growth and establishment in the greenhouse and field. In the greenhouse, we observed low to moderate levels of insect infection in G. mellonella bioassays, with infection levels varying based on the fungal species. In the field, insect infections from Beauveria spp. were much lower than in the greenhouse, while infections from Metarhizium spp. were higher than in the greenhouse, though infection levels of both fungi varied seasonally. Our findings suggest that EPF acted as a biostimulant in seed treatments that benefited turfgrass establishment and improved stand density early on; however, the potential secondary benefits for biological control of soil-dwelling insects were limited.
Agricultural soils are sources of nitrous oxide (N2O) and, under prolonged saturation, methane (CH4)-two potent greenhouse gases (GHGs). Soil management, field topography, and climate all influence GHG emissions, yet their interactions are not well understood. Over 17 months, we evaluated how three distinct management systems-Conventional, a soil health system (Soil Health), and a flocculated manure solid amendment (Flocculated Solids)-interacted with topographically high and low areas to influence N2O and CH4 emissions in a 21 ha corn (Zea mays L.) silage field in western Vermont, during a period of abnormally high precipitation. At 18 plots (3 treatments × 2 topographic positions × 3 replicates), we measured GHG fluxes year-round alongside soil temperature, moisture, and inorganic nitrogen. Annual N2O emissions were 4.4 times greater in Soil Health-Low plots (74.3 kg N2O-N ha-1 year-1) than in Flocculated Solids plots, which had the lowest emissions (17.0 kg N2O-N ha-1 year-1). Annual CH4 emissions were greatest in low plots across all treatments, with low plots emitting 2.2 times more CH4 than high plots. Boosted regression tree models identified soil moisture, ammonium, CO2 flux, and nitrate as the strongest predictors of daily N2O fluxes. For CH4, inundation duration was the dominant driver, with emissions increasing sharply after >40 days of continuous saturation. Treatment and topography explained <5% of emissions in both models, indicating that their effects are primarily indirect, modifying soil moisture, nitrogen availability, and organic matter inputs that ultimately drive GHG emissions. Greenhouse gases are naturally released from soil. However, the rate and magnitude of these emissions depend on how agricultural soils are managed, where they are within a field, and weather conditions. We studied nitrous oxide and methane emissions in a Vermont cornfield managed under three different systems across high and low landscape positions during an unusually wet growing season. Emissions were greatest in the wetter, low‐lying areas of the field where liquid manure was injected into the soil and lowest where a drier manure product was applied at a lower nitrogen rate. Soil moisture and available nutrients were the strongest factors controlling emissions, meaning that practices that increase nitrogen retention or soil wetness may also increase gaseous losses. These findings highlight the need for field‐specific management that accounts for environmental conditions and landscape position, especially as extreme precipitation becomes more common with climate change.
Mito Thermo Yellow (MTY) is a mitochondrially targeted fluorophore that shows marked fluorescence quenching with increasing temperature, allowing for interrogating temperature dynamics in the mitochondria of live cells. Here we re-evaluate published MTY fluorescence responses used to argue in favor of the 'hot mitochondria' concept; the assertion that mitochondria operate while maintaining substantial (> 10°C) apparent temperature gradients (ΔTapp) between themselves and their cellular environment. We find that MTY fluorescence kinetics are incompatible with the expected dynamics of mitochondrial heat production and diffusion. We further explore the published effects of mitochondrial inhibitors on MTY, and related evidence for ΔTapp of > 10°C, again concluding results are inconsistent with the expected heat production dynamics. Thus, assertions of ΔTapp > 10°C between mitochondria and their cellular environment based on MTY fluorescence intensity changes are unlikely to be reporting a signal that is uniquely intramitochondrial temperature. In addition to these analyses, we further argue that the inference mitochondria can operate at an internal temperature of > 48°C, as reported using MTY, is improbable as these internal temperatures would cause protein denaturation and aggregation and induction of the heat shock (HSR), unfolded protein (UPR), and integrated (ISR) stress responses. Taken as a whole, we conclude MTY and similar tools must be re-evaluated in regard to if they are providing solely information on local temperature and thus are so far inadequate, unto themselves, to demonstrate the existence of hot mitochondria.
Many terrestrial ectotherms (amphibians, reptiles) select warm retreat sites which may provide opportunities to escape the impacts of pathogens that cannot tolerate high temperatures. Recent research has exploited this mismatch in host-pathogen thermal tolerance by providing sun-heated artificial hotspot shelters to protect endangered frogs from the amphibian chytrid fungus (Batrachochytrium dendrobatridis), which causes the disease chytridiomycosis. Artificial shelters comprised of masonry bricks and small greenhouses allow endangered frogs to stay warm in winter, reducing and clearing chytrid infections and developing resistance to future infection even under cold temperatures. Such shelters can be a valuable tool for conservation in sunny cool weather, but cloudy weather reduces the thermal benefit; and in too-cool conditions the warming creates a thermal regime where chytrid could grow faster. We monitored temperatures inside hotspot shelters constructed at two sites in Australia over winter: one in a cool semi-arid climate (Werribee, Victoria, Australia), and one in a humid subtropical climate (Sydney, NSW, Australia), to evaluate the thermal performance of shelters in different chytrid-impacted climates. Our monitoring of temperatures inside hotspot shelters found minor-to-negative outcomes at the cooler site, with shelters in Werribee exceeding 25°C for at least 1 h on only 13.1% of days, compared to 82.5% of days at the Sydney site. Hotspot shelters have great potential for frog conservation, but they are not a panacea because diversity in habitat conditions and target species responses will influence their success.
Deforestation reshuffles communities across landscapes with myriad consequences for ecosystem function. Following deforestation, rapid exposure to novel microclimates can act as a strong environmental filter, favoring warm-adapted species and decoupling trophic interactions. Forest restoration may partly reverse this process through increased food resources, structural complexity of habitat, and buffering of microclimates-each potentially modified by tree diversity. Despite growing evidence that tree diversity and cool microclimates help maintain animal diversity in natural forests, less is known about how these factors shape species assemblages or multi-trophic dynamics in restoration areas. Here, using surveys and two field experiments within a long-term tree planting experiment, we assessed the relative effects of tree diversity, forest structure, and associated microclimate on fine-scale space use by birds and their top-down impacts on insects. Surveys showed that the probability of occurrences of birds increased in cooler plots, which were associated with higher tree diversity and vertical complexity. The strength of microclimate effects on bird occurrences was strongest for species that are forest specialists. To assess risk to insect herbivores from avian predation, we used a sentinel prey experiment and found that predation risk increased in warmer plots, counter to our expectations based on bird surveys. Last, we examined top-down effects of bird exclusion on leaf herbivory, finding that skeletonizing patterns of herbivory increased in exclosures and in cooler plots. Taken together, these results suggest that microclimate resulting from variation in forest structure shapes the space use of birds at fine scales with complex outcomes for bird-herbivore-tree interactions in planted forests. Active restoration methods that enhance below-canopy cooling may improve biodiversity outcomes and help maintain species interactions that underlie many ecosystem functions.
This study focuses on evaluating the thermoregulatory performance of a graphene-based electric heating cape and determining its optimal temperature for use in cool indoor environments during winter. Through controlled experiments with 30 participants in a climate chamber maintained at 15.5 °C, five heating conditions (no heating, 35 °C, 40 °C, 45 °C, and 50 °C) were systematically tested. Skin temperature and heart rate were continuously monitored, and subjective thermal sensation and comfort votes were collected using 7-point scales. Results demonstrated that the electric heating cape significantly improved thermal comfort, with 40 °C identified as the optimal temperature setpoint: overall thermal sensation shifted from slightly cool to slightly warm, and overall thermal comfort state attained 'slightly comfortable' level on the adaptive comfort scale. Repeated-measures ANOVA revealed that heating temperature had a highly significant effect on both overall thermal sensation and overall thermal comfort. Post-hoc tests identified 40 °C as the optimal temperature setpoint under these environmental conditions (15.5 °C). At this temperature, the overall thermal sensation vote improved significantly from - 1.23 (no heating) to -0.13 (p < 0.01), approaching a neutral sensation, while overall thermal comfort increased significantly from - 1.08 to 0.35, reaching a "slightly comfortable" level. The most significant improvements were observed in the abdomen and lumbar regions. While skin temperature showed a positive correlation with thermal perception, heart rate remained stable (± 5 bpm), indicating a low physiological burden. Marked individual differences in temperature preference underscore the importance of personalized thermal regulation. This study provides empirical evidence to guide the application and control of localized heating devices in cool indoor office settings during winter.
Animal coloration has diverse functions, such as camouflage, communication, thermoregulation, and protection from UV damage and more, and can be shaped by environmental selective pressures. Some climatic selective pressures are strong enough to produce consistent patterns in many species across large-scale geographic gradients, leading to the creation of macrophysiological rules such as Gloger's rule, which predicts that endothermic populations in hot, humid areas will be visibly darker than those in cool, dry areas, and the thermal melanism hypothesis, which predicts that ectothermic animals will be visibly darker in cooler areas. While these rules often capture trends in animal absorptance in the visible spectrum, wavelengths of visible light are not the only relevant wavelengths to an animal's energy budget: solar radiation extends beyond the visible spectrum [0.4-0.7 μm] into the near-infrared; thus, thermal pressures may result in changes in surface reflectance characteristics beyond the visible [e.g., 0.7-2.5 μm] in birds. Further, heat exchange with the environment extends into the mid-infrared (MIR), including heat loss through the atmospheric transparency window [8-14 μm]. It is unknown whether animal absorptance in the NIR or emittance in MIR might also follow macrophysiological rules, as seen in the visible spectrum, such as more absorptance of NIR and less emittance of MIR in cooler areas for ectotherms under the thermal melanism hypothesis. Here, we examine both UV-NIR absorptance and MIR emittance in five species of birds: the Great Horned Owl, Northern Bobwhite, Steller's Jay, Song Sparrow, and Common Raven. We show that NIR absorptance varies by species and population, corresponding to their habitat and thermoregulatory strategies. MIR emittance, in contrast, was stable across species and populations but differed slightly across populations of Northern Bobwhites. We conclude by highlighting the importance of considering the full spectrum from UV to MIR in research on animal adaptation. Further consideration of infrared radiation is necessary for a complete view of animals' phenotypic diversity and possible responses to thermal challenge. La coloration animale a des fonctions diverses telles que le camouflage, la communication, la thermorégulation, la protection contre les dommages dus aux UV et bien d’autres. Elle peut être façonnée par des pressions sélectives environnementales. Certaines pressions sélectives climatiques sont suffisamment fortes pour produire des motifs cohérents chez de nombreuses espèces le long de gradients géographiques à grande échelle, conduisant à la création de règles macrophysiologiques. Par exemple, la règle de Gloger prédit que les populations endothermes dans des zones chaudes et humides seront visiblement plus sombres que celles des zones fraîches et sèches, et l’hypothèse du mélanisme thermique, qui prédit que les animaux ectothermes seront visiblement plus sombres dans les zones plus fraîches. Bien que ces règles rendent souvent compte des tendances de l’absorbance des animaux dans le spectre visible, les longueurs d’onde de la lumière visible ne sont pas les seules pertinentes pour le budget énergétique d’un animal : le rayonnement solaire s’étend au-delà du spectre visible [0.4–0.7 μm] dans le proche infrarouge (IR). Ainsi, les pressions thermiques peuvent entraîner des modifications de la réflectance au-delà du visible [e.g., 0.7–2.5 μm] chez les oiseaux. En outre, les échanges de chaleur avec l’environnement s’étendent à l’infrarouge moyen, y compris la perte de chaleur MIR à travers la fenêtre de transmission atmosphérique [8–14 μm]. On ignore si l’absorbance animale dans le proche IR ou l’émittance dans l’IR moyen pourraient également suivre des règles macrophysiologiques, comme observé dans le spectre visible, comme par exemple, une plus grande absorbance dans le proche IR et une moindre émittance dans l’IR moyen dans les zones plus froides chez les ectothermes selon l’hypothèse du mélanisme thermique. Ici, nous examinons à la fois l’absorbance de l’UV au proche infrarouge et l’émittance dans l’infrarouge moyen chez cinq espèces d’oiseaux : le Grand-duc d’Amérique, le Colin de Virginie, le Geai de Steller, le Bruant chanteur et le Grand Corbeau. Nous montrons que l’absorbance dans l’infrarouge proche varie selon les espèces et les populations, en fonction de leur habitat et de leurs stratégies de thermorégulation. L’émittance dans l’infrarouge moyen, en revanche, est restée stable entre les espèces et les populations, mais différait légèrement entre les populations de Colin de Virginie. Nous concluons en soulignant l’importance de considérer l’ensemble du spectre de l’UV à l’infrarouge moyen dans la recherche sur l’adaptation animale. Une prise en compte plus approfondie du rayonnement infrarouge est nécessaire pour obtenir une vision complète de la diversité phénotypique des animaux et de leurs réponses possibles aux contraintes thermiques.
We studied near-instantaneous temperature responses of light-saturated photosynthesis (Asat) and the operating efficiency of photosystem II (ΦPSII) in relation to acclimation of photosynthetic biochemistry to temperature at the timescale of 1-8 days. We grew two closely related Brassica oleracea L. accessions under diurnal temperature ranges of 15°C-25°C and 5°C-15°C, representing the warm and cool native environments of the two accessions. Near-instantaneous temperature responses of Asat and ΦPSII were measured on acclimated plants exposed to a temperature ramp from 10°C to 45°C. Biochemical acclimation was quantified by switching plants between warm and cool regimes before measuring photosynthetic variables at Day 1 and Day 8 after the switch. Near-instantaneous temperature optima of Asat and ΦPSII functionally shifted towards the acclimated growth temperatures in both accessions, and both accessions achieved their highest instantaneous maximum values of Asat and ΦPSII when grown under representative native regimes. Differences in maximum carboxylation capacity were evident by Day 1; no further change was detected by Day 8. Our results highlight functional coordination between adaptation, acclimation and near-instantaneous temperature responses of photochemistry and biochemistry. Moreover, our results suggest photosynthetic biochemistry can acclimate to temperature changes within a day.
Although sunshine duration (SSD) has been associated with episodes of mental disorders, the existing evidence remains conflicting, and previous studies have overlooked the role of ambient temperature-a factor intertwined with sunlight exposure-in this association. The present study aimed to investigate the associations of SSD over short periods with risks of depressive, anxiety and schizophrenia episodes, and estimate the possible effect modification by ambient temperature. Based on hospital admission data from the urban basic medical health insurance systems in China across 268 Chinese cities from January 1, 2013, to December 31, 2017, we conducted a nationwide time-stratified case-crossover study. The primary outcomes were episodes of depressive disorder, anxiety disorder, and schizophrenia. The individuals hospitalized for episodes of depressive disorder, anxiety disorder, and schizophrenia were included based on ICD-10 diagnosis codes. In addition to daily SSD, SSD increases between neighboring days (SDIN) over consecutive days were calculated to capture multi-day relative increases in SSD. Individuals served as their own controls, and the estimations were obtained using the conditional logistic regression models. A total of 330,610, 221,332, and 817,296 hospital admissions for depressive disorder, anxiety disorder, and schizophrenia were included, respectively. After considering the effect modification by temperature, significant negative associations between SSD and hospital admissions for depressive disorder and schizophrenia were found mainly in the cool season: per 1-h increase in 13-day moving average SSD was associated with decreases of 3.33% (95% CI: -5.85%, -0.73%) and 2.60% (95% CI: -4.21%, -0.96%) in hospital admissions for depressive disorder and schizophrenia, respectively. Ambient temperature showed inverse modification on the SSD-admission associations. When stratified by temperature, significant negative associations between SSD and hospital admissions for depressive disorder and schizophrenia were observed in low temperature stratum (< median), whereas no significant association was found in the high temperature stratum (≥ the median). Additionally, increases in 13-day moving average SDIN were associated with significant additional decreases in admissions for depressive disorder and schizophrenia. Shot-term exposure to increasing SSD was associated with decreases in episode risks of depressive disorder and schizophrenia, and such associations were more apparent at low temperatures. Increasing the duration of sunlight exposure and reducing exposure to increasing temperature, especially in the cool season, may help reduce the burdens of depressive disorder and schizophrenia.
Urban heat island (UHI) effects, exacerbated by climate change, highlight the urgent need for effective management of urban green spaces (UGSs) to regulate city temperatures. However, previous studies primarily concentrated on the effects of landscape composition and configuration on mitigating urban heat islands. To address this gap, this study develops a connectivity-based framework to examine the spatiotemporal evolution of urban green spaces in Tehran, Iran, using satellite data from 2015 to 2023 processed in Google Earth Engine. Landsat-derived land surface temperature (LST) and NDVI maps were used to identify urban heat and cool islands. ROC and TSS metrics were applied to determine an optimal NDVI threshold for classifying green and non-green areas. Landscape morphology metrics quantified spatial configuration changes, while Foreground Area Density and inverse NDVI maps were used to detect core green spaces and resistance surfaces, respectively. Connectivity flows between cold cores were modeled using electrical circuit theory. Results revealed a significant decrease of 1,400 ha in cold areas in northern Tehran and a 1,618 ha increase in hot zones in the south and southwest. Spatial analysis revealed increased cold patch fragmentation and hot zone expansion, reducing green space continuity and intensifying the UHI effect. While cold cores in 2015 showed weak, scattered connectivity, by 2023 they became more concentrated in northern Tehran with a marked increase in current flow, indicating improved local connectivity. However, this concentration reveals growing imbalance in UGS distribution and cooling capacity, highlighting the need for targeted green infrastructure in southern, western, and central areas. The findings offer valuable insights for urban planners to enhance UGS connectivity and mitigate UHI effects, supporting climate resilience and improving urban quality of life.