Intracerebroventricular administration of TRH Agonist, RX-77368 alleviates visceral pain induced by colorectal distension in rats

Thyrotropin-releasing hormone (TRH) acts centrally to exert pleiotropic actions independently from its endocrine function, including antinociceptive effects against somatic pain in rodents. Whether exogenous or endogenous activation of TRH signaling in the brain modulates visceral pain is unknown. Adult male Sprague-Dawley rats received an intracerebroventricular (ICV) injection of the stable TRH analog, RX-77368 (10, 30 and 100 ng/rat) or saline (5 µl) or were semi-restrained and exposed to cold (4°C) for 45 min. The visceromotor response (VMR) to graded phasic colorectal distensions (CRD) was monitored using non-invasive intracolonic pressure manometry. Naloxone (1 mg/kg) was injected subcutaneously 10 min before ICV RX-77368 or saline. Fecal pellet output was monitored for 1 h after ICV injection. RX-77368 ICV (10, 30 and 100 ng/rat) reduced significantly the VMR by 56.7%, 67.1% and 81.1% at 40 mmHg and by 30.3%, 58.9% and 87.4% at 60 mmHg respectively vs ICV saline. Naloxone reduced RX-77368 (30 and 100 ng, ICV) analgesic response by 51% and 28% at 40 mmHg and by 30% and 33% at 60 mmHg respectively, but had no effect per se. The visceral analgesia was mimicked by the acute exposure to cold. At the doses of 30 and 100 ng, ICV RX-77368 induced defecation within 30 min. These data established the antinociceptive action of RX-77368 injected ICV in a model of visceral pain induced by colonic distension through recruitment of both opioid and non-opioid dependent mechanisms.

24-h passive heat and cold exposures did not modify energy intake and appetite but strongly modify food reward

Effects of acute thermal exposures on appetite appear hypothetical in reason of very heterogeneous methodologies. The aim of this study was therefore to clearly define the effects of passive 24-h cold (16°C) and heat (32°C) exposures on appetitive responses compared to a thermo neutral condition (24°C). Twenty-three healthy, young, and active male participants realised three sessions (from 1 pm) in a laboratory conceived like an apartment dressed with the same outfit (Clo=1). Three meals composed of three or four cold or warm dishes were served ad libitum to assess energy intake (EI). Leeds Food Preference Questionnaires were used before each meal to assess food reward. Subjective appetite was regularly assessed and levels of appetitive hormones (acylated ghrelin, GLP-1, leptin, and PYY) were assessed before and after the last meal (lunch). Contrary to the literature, total EI was not modified by cold or heat exposure (p=0.120). Accordingly, hunger scores (p=0.554) were not altered. Levels of acylated ghrelin and leptin were marginally higher during the 16 (p=0.032) and 32°C (p<0.023) sessions, respectively. Interestingly, implicit wanting for cold and low-fat foods at 32°C and for warm and high-fat foods at 16°C were increased during the whole exposure (p < 0.024). Moreover, cold entrées were more consumed at 32 °C (p<0.062) and warm main dishes more consumed at 16°C (p<0.025). Thus, passive cold and hot exposures had limited effects on appetite and it seems that offering some choice based on food temperature may help individuals to express their specific food preferences and maintain EI.

Warming, but not infection with Borrelia burgdorferi, increases off-host winter activity in the ectoparasite, Ixodes scapularis

Warming winters will change patterns of behaviour in temperate and polar arthropods, but we know little about the drivers of winter activity in animals such as ticks. Any changes in behaviour are likely to arise from a combination of both abiotic (e.g. temperature) and biotic (e.g. infection) drivers, and will have important consequences for survival and species interactions. Blacklegged ticks, Ixodes scapularis, have invaded Atlantic Canada and high proportions (30-50%) are infected with the bacteria causing Lyme disease, Borrelia burgdorferi. Infection is correlated with increased overwintering survival of adult females, and ticks are increasingly active in the winter, but it is unclear if infection is associated with activity. Further, we know little about how temperature drives the frequency of winter activity. Here, we exposed wild-caught, adult, female Ixodes scapularis ticks to three different winter temperature regimes (constant low temperatures, increased warming, and increased warming + variability) to determine the thermal and infection conditions that promote or suppress activity. We used automated behaviour monitors to track daily activity in individual ticks and repeated the study with fresh ticks over three years. Following exposure to winter conditions we determined whether ticks were infected with the bacteria B. burgdorferi and if infection was responsible for any patterns in winter activity. Warming conditions promoted increased activity throughout the overwintering period but infection with B. burgdorferi had no impact on the frequency or overall number of ticks active throughout the winter. Individual ticks varied in their levels of activity throughout the winter, such that some were largely dormant for several weeks, while others were active almost daily; however, we do not yet know the drivers behind this individual variation in behaviour. Overall, warming winters will heighten the risk of tick-host encounters.

Emerging effects of temperature on human cognition, affect, and behaviour

Human body core temperature is tightly regulated within approximately 37 °C. Global near surface temperature has increased by over 1.2 °C between 1850 and 2020. In light of the challenge this poses to human thermoregulation, the present perspective article sought to provide an overview on the effects of varying ambient and body temperature on cognitive, affective, and behavioural domains of functioning. To this end, an overview of observational and experimental studies in healthy individuals and individuals with mental disorders was provided. Within body core temperature at approximately 37 °C, relatively lower ambient and skin temperatures appear to evoke a need for social connection, whereas comparably higher temperatures appear to facilitate notions of other as closer and more sociable. Above-average ambient temperatures are associated with increased conflicts as well as incident psychotic and depressive symptoms, mental disorders, and suicide. With mild hypo- and hyperthermia, paradoxical effects are observed: whereas the acute states are generally characterised by impairments in cognitive performance, anxiety, and irritability, individuals with depression experience longer-term symptom improvements with treatments deliberately inducing these states for brief amounts of time. When taken together, it has thus become clear that temperature is inexorably associated with human cognition, affect, and (potentially) behaviour. Given the projected increase in global warming, further research into the affective and behavioural sequelae of heat and the mechanisms translating it into mental health outcomes is urgently warranted.

Independent, additive and interactive effects of acute normobaric hypoxia and cold on submaximal and maximal endurance exercise

PURPOSE

To evaluate the independent and combined effects of hypoxia (FiO2 = 13.5%) and cold (- 20 °C) on physiological and perceptual responses to endurance exercise.

METHODS

14 trained male subjects ( V . O2max: 64 ± 5 mL/kg/min) randomly performed a discontinuous maximal incremental test to exhaustion on a motorized treadmill under four environmental conditions: Normothermic-Normoxia (N), Normothermic-Hypoxia (H), Cold-Normoxia (C) and Cold-Hypoxia (CH). Performance and physiological and perceptual responses throughout exercise were evaluated.

RESULTS

Maximal WorkLoad (WL) and WL at lactate threshold (LT) were reduced in C (- 2.3% and - 3.5%) and H (- 18.0% and - 21.7%) compared to N, with no interactive (p = 0.25 and 0.81) but additive effect in CH (- 21.5% and - 24.6%). Similarly, HRmax and Vemax were reduced in C (- 3.2% and - 14.6%) and H (- 5.0% and - 7%), showing additive effects in CH (- 7.7% and - 16.6%). At LT, additive effect of C (- 2.8%) and H (- 3.8%) on HR reduction in CH (- 5.7%) was maintained, whereas an interactive effect (p = 0.007) of the two stressors combined was noted on Ve (C: - 3.1%, H: + 5.5%, CH: - 10.9%). [La] curve shifted on the left in CH, displaying an interaction effect between the 2 stressors on this parameter. Finally, RPE at LT was exclusively reduced by hypoxia (p < 0.001), whereas TSmax is synergistically reduced by cold and hypoxia (interaction p = 0.047).

CONCLUSION

If compared to single stress exposure, exercise performance and physiological and perceptual variables undergo additive or synergistic effects when cold and hypoxia are combined. These results provide new insight into human physiological responses to extreme environments.

Evaluation of the efficacy of a light ration adapted to cold weather during a 20-day expedition in Greenland

INTRODUCTION

Limiting body mass loss during military expeditions/training in the cold by providing rations containing easy-to-use, highly palatable, and familiar foods is feasible, but the bulk/weight is too high to be realistically used in a military context. We carried out an analysis of lighter rations adapted to cold weather (1,011 g, 15.7 MJ/3750 kcal) during a 20-day expedition in Greenland.

METHODS

Ten French soldiers daily reported all foods and beverages consumed, the reasons they did not consume certain foods, the palatability of each consumed food, the timing of intake, and the sensation of hunger using a diary.

RESULTS

Although energy intake increased in the 3rd week (vs 1st week; p = 0.015), it was insufficient to prevent the loss of body mass (-4.2 ± 1.9 kg, p = 0.002). More extensive analyses showed that 1) energy intake increased only during dinner (p = 0.024) and that hunger levels continued to increase before dinner (p = 0.029), 2) palatability increased during the 3rd week (vs 1st week) especially for savory day foods (p< 0.001), and 3) lack of hunger and lack of appeal (33 % each) were the main reasons for not consuming certain items.

CONCLUSION

Soldiers placed in total autonomy during a 20-day expedition in the cold and provided rations that were slightly undersized but adapted for cold conditions, surprisingly, remained picky, leading to large losses of body mass. Our results suggest a margin for improvement to stimulate spontaneous food intake. For example, more energy-dense and savory foods during the day and the replacement of certain disliked items.

reveals that DoWRKY71 enhanced the tolerance to cold and ABA stress

WRKY transcription factors constitute one of the largest plant-specific gene families, regulating various aspects of plant growth, development, physiological processes, and responses to abiotic stresses. This study aimed to comprehensively analyze the WRKY gene family of yam (Dioscorea opposita Thunb.), to understand their expression patterns during the growth and development process and their response to different treatments of yam and analyze the function of DoWRKY71 in detail. A total of 25 DoWRKY genes were identified from the transcriptome of yam, which were divided into six clades (I, IIa, IIc, IId, IIe, III) based on phylogenetic analysis. The analysis of conserved motifs revealed 10 motifs, varying in length from 16 to 50 amino acids. Based on real-time quantitative PCR (qRT-PCR) analysis, DoWRKY genes were expressed at different stages of growth and development and responded differentially to various abiotic stresses. The expression level of DoWRKY71 genes was up-regulated in the early stage and then down-regulated in tuber enlargement. This gene showed responsiveness to cold and abiotic stresses, such as abscisic acid (ABA) and methyl jasmonate (MeJA). Therefore, further study was conducted on this gene. Subcellular localization analysis revealed that the DoWRKY71 protein was localized in the nucleus. Moreover, the overexpression of DoWRKY71 enhanced the cold tolerance of transgenic tobacco and promoted ABA mediated stomatal closure. This study presents the first systematic analysis of the WRKY gene family in yam, offering new insights for studying WRKY transcription factors in yam. The functional study of DoWRKY71 lays theoretical foundation for further exploring the regulatory function of the DoWRKY71 gene in the growth and development related signaling pathway of yam.

Impaired autophagy following ex vivo cooling of simulated hypothermic temperatures in peripheral blood mononuclear cells from young and older adults

Hypothermia is a critical consequence of extreme cold exposure that increases the risk of cold-related injury and death in humans. While the initiation of cytoprotective mechanisms including the process of autophagy and the heat shock response (HSR) is crucial to cellular survival during periods of stress, age-related decrements in these systems may underlie cold-induced cellular vulnerability in older adults. Moreover, whether potential sex-related differences in autophagic regulation influence the human cold stress response remain unknown. We evaluated the effect of age and sex on mechanisms of cytoprotection (autophagy and the HSR) and cellular stress (apoptotic signaling and the acute inflammatory response) during ex vivo hypothermic cooling. Venous blood samples from 20 healthy young (10 females; mean [SD]: 22 [2] years) and 20 healthy older (10 females; 66 [5] years) adults were either isolated immediately (baseline) for peripheral blood mononuclear cells (PBMCs) or exposed to water bath temperatures maintained at 37, 35, 33, 31, or 4 °C for 90 min before PBMC isolation. Proteins associated with autophagy, apoptosis, the HSR, and inflammation were analyzed via Western blotting. Indicators of autophagic initiation and signaling (LC3, ULK1, and beclin-2) and the HSR (HSP90 and HSP70) increased when exposed to hypothermic temperatures in young and older adults (all p ≤ 0.007). Sex-related differences were only observed with autophagic initiation (ULK1; p = 0.015). However, despite increases in autophagic initiators ULK1 and beclin-2 (all p < 0.001), this was paralleled by autophagic dysfunction (increased p62) in all groups (all p < 0.001). Further, apoptotic (cleaved-caspase-3) and inflammatory (IL-6 and TNF-α) signaling increased in all groups (all p < 0.001). We demonstrated that exposure to hypothermic conditions is associated with autophagic dysfunction, irrespective of age or sex, although there may exist innate sex-related differences in cytoprotection in response to cold exposure as evidenced through altered autophagic initiation.

Maternal exposure to ambient air temperature and adverse birth outcomes: An umbrella review of systematic reviews and meta-analyses

BACKGROUND

Multiple systematic reviews on prenatal ambient temperature and adverse birth outcomes exist, but the overall epidemiological evidence and the appropriate metric for thermal stress remain unclear. An umbrella review was performed to summarise and appraise the evidence with recommendations.

METHODS

Systematic reviews and meta-analyses on the associations between ambient temperature and adverse birth outcomes (preterm birth, stillbirth, birth weight, low birth weight, and small for gestational age) up to December 20, 2023, were synthesised according to a published protocol. Databases PubMed, CINAHL, Scopus, MEDLINE/Ovid, EMBASE/Ovid, Web of Science Core Collection, systematic reviews repositories, electronic grey literature, and references were searched. Risk of bias was assessed using Joanna Briggs Institute's critical appraisal tool.

RESULTS

Eleven systematic reviews, including two meta-analyses, were included. This comprised 90 distinct observational studies that employed multiple temperature assessment metrics with a very high overlap of primary studies. Primary studies were mostly from the United States while both Africa and South Asia contributed only three studies. A majority (7 out of 11) of the systematic reviews were rated as moderate risk of bias. All systematic reviews indicated that maternal exposures to both extremely high and low temperatures, particularly during late gestation are associated with increased risks of preterm birth, stillbirth, and reduced fetal growth. However, due to great differences in the exposure assessments, high heterogeneity, imprecision, and methodological limitations of the included systematic reviews, the overall epidemiological evidence was classified as probable evidence of causation. No study assessed biothermal metrics for thermal stress.

CONCLUSIONS

Despite the notable methodological differences, prenatal exposure to extreme ambient temperatures, particularly during late pregnancy, was associated with adverse birth outcomes. Adhering to the appropriate systematic review guidelines for environmental health research, incorporating biothermal metrics into exposure assessment, evidence from broader geodemographic settings, and interventions are recommended in future studies.

Integrating Shared Socioeconomic Pathway-informed adaptation into temperature-related mortality projections under climate change

The extent to which populations will successfully adapt to continued warming temperatures will be a crucial factor in determining future health burdens. Previous health impact assessments of future temperature-related mortality burdens mostly disregard adaptation or make simplistic assumptions. We apply a novel evidence-based approach to model adaptation that takes into account the fact that adaptation potential is likely to vary at different temperatures. Temporal changes in age-specific mortality risk associated with low and high temperatures were characterised for Scotland between 1974 and 2018 using temperature-specific RR ratios to reflect past changes in adaptive capacity. Three scenarios of future adaption were constructed consistent with the SSPs. These adaptation projections were combined with climate and population projections to estimate the mortality burdens attributable to high (above the 90th percentile of the historical temperature distribution) and low (below the 10th percentile) temperatures up to 2080 under five RCP-SSP scenarios. A decomposition analysis was conducted to attribute the change in the mortality burden into adaptation, climate and population. In 1980-2000, the heat burden (21 deaths/year) was smaller than the colder burden (312 deaths/year). In the 2060-2080 period, the heat burden was projected to be the highest under RCP8.5-SSP5 (1285 deaths/year), and the cold burden was the highest under RCP4.5-SSP4 (320 deaths/year). The net burden was lowest under RCP2.6-SSP1 and highest under RCP8.5-SSP5. Improvements in adaptation was the largest factor reducing the cold burden under RCP2.6-SSP1 whilst temperature increase was the biggest factor contributing to the high heat burdens under RCP8.5-SSP5. Ambient heat will become a more important health determinant than cold in Scotland under all climate change and socio-economic scenarios. Adaptive capacity will not fully counter projected increases in heat deaths, underscoring the need for more ambitious climate mitigation measures for Scotland and elsewhere.

in response to cold stress

Cold stress, as an abiotic stress, is one of the most limiting factors which pose a great threat to the plant's productivity. To understand the transcriptional regulation and connectivity pattern of genes involved in barley cold stress responses, co-expression network analysis was performed based on the global transcriptome profiling. The microarray datasets related to cold stress treatments were retrieved from the Gene Expression Omnibus (GEO) and Array express databases. Four microarray datasets related to cold stress-responsive transcriptome in barley were included in our study. Gene co-expression analysis was constructed using WGCNA method. Module-Trait Relationships (MTR) analysis and hub genes determination and validation were carried out. Finally, transcription factor and kinase regulatory networks were Inferred using machine learning algorithm. The co-expression modules were determined using beta index = 10. In total 13 co-expressed modules were identified with an average size of 153 genes. Functional enrichment based on gene ontology (GO) showed that each of the stress related significant modules were enriched in different biological processes. Annotation of significant modules identifies some TFs and Kinases such as ethylene-responsive transcription factor 1-like, transcription factor PCL1-like, transcription factor MYC2, WRKY, serine/threonine-protein kinase PBL7, and receptor-like protein kinase At2g42960 were contributed in barley cold stress response. Our analysis highlighted the functional importance of ABA signaling pathway, ROS signaling, defensive and protective proteins, degrading protein, Ca2+ related signaling, ribosome-mediated translation and etc. in responding of barley to cold stress condition. The current findings add substantially to our understanding of the cold responsive underlying mechanism of barley which can serve in future studies and breeding programs.

Transcriptome, histological, and physiological responses of Amur sleeper (Perccottus glenii) during cold stress, freezing, and recovery

Freeze tolerance is a survival strategy employed by some ectotherms living in extremely cold environments. Some fish in extremely cold areas can recover from their frozen state, but they also have to endure cold stress. Amur sleeper (Perccottus glenii) can recover from a completely frozen state. To explore the response of freeze-resistant fish to low temperatures, we analyzed histological alterations, and antioxidant and carbohydrate-lipid metabolizing enzymes of P. glenii under low temperatures. So far, sensory genes regulating P. glenii during cold stress, freezing, and recovery have not been identified. Ultrastructure results indicated that glycogen content and mitochondrial ridge decreased during cold stress and freezing, whereas the number of endoplasmic reticulum increased during recovery. Plasma glucose and glycerol levels of the three treatment groups significantly increased. Lactate dehydrogenase and pyruvate kinase levels significantly increased during cold stress and freezing, and hexokinase levels significantly increased during cold stress. In total, 30,560 unigenes were found (average length 1724 bp, N50 2843 bp). In addition, 7370 differentially expressed genes (DEGs; including 2938 upregulated genes and 4432 downregulated genes) were identified. KEGG analysis revealed that the DEGs were enriched in carbohydrate and lipid metabolism, lipid synthesis, immune system, and anti-apoptosis. Genes involved in glycolysis and phospholipid metabolism were significantly upregulated during cold stress; genes related to circadian rhythm, oxidative phosphorylation, and lipid synthesis were significantly upregulated during freezing; and genes involved in the immune system and anti-apoptosis were significantly upregulated during recovery. Our results attempt to offer new insights into the physiological mechanisms of complex adaptation in P. glenii and provide useful information for future studies on the mechanism underlying freezing/recovery in animals.

Comparison of the Efficacy and Safety of Pulp Sensitivity Testing Results Using a New Pulp Testing Device versus Some Commonly Used Methods: A Crossover Study

INTRODUCTION

The efficacy and safety of a single novel electronic pulp sensitivity tester with a transilluminator (PSTT) capable of providing 4 different tests was compared with gold standard (GS) pulp testing methods.

METHODS

Four hundred eighty teeth, including 3 from each quadrant and their contralateral and opposing teeth, were randomly assessed using the PSTT or GS methods. Seven days later, the same teeth were assessed using the method not used earlier so that all teeth were evaluated using both methods. Sixty previously root canal-treated teeth, serving as negative controls, were assessed identically to the experimental groups. Results were analyzed using IBM SPSS software (IBM Corp, Armonk, NY) (P < .05).

RESULTS

A higher percentage of teeth responded to cold and electricity using GS methods compared with the PSTT (99.4 vs 93.1 and 99.6 vs 97.3, respectively). A lower percentage of teeth responded to heat using the GS method compared with the PSTT (50.0 vs 68.1). Chi-square tests determined differences in the proportion of sensitivity to temperature, and electric testing methods were statistically significant (P < .001 and P = .004, respectively). No difference in the proportion of sensitivity was observed for transillumination. The Wilcoxon signed rank test determined significantly shorter cold testing times using the GS method (P = .024). Shorter testing times were observed using the PSTT for heat (P < .001), electric pulp testing (P = .048), and transillumination (P = .001). The overall PSTT testing time was significantly shorter than the GS testing time (P = .03). Tissue injury was not observed.

CONCLUSIONS

The PSTT efficiently and safely provided heat and transillumination for pulpal diagnosis. Improvements are needed to enhance the cold and electric stimulus efficacy.

The effect of temporal data aggregation to assess the impact of changing temperatures in Europe: an epidemiological modelling study

Background

Daily time-series regression models are commonly used to estimate the lagged nonlinear relation between temperature and mortality. A major impediment to this type of analysis is the restricted access to daily health records. The use of weekly and monthly data represents a possible solution unexplored to date.

Methods

We temporally aggregated daily temperatures and mortality records from 147 contiguous regions in 16 European countries, representing their entire population of over 400 million people. We estimated temperature-lag-mortality relationships by using standard time-series quasi-Poisson regression models applied to daily data, and compared the results with those obtained with different degrees of temporal aggregation.

Findings

We observed progressively larger differences in the epidemiological estimates with the degree of temporal data aggregation. The daily data model estimated an annual cold and heat-related mortality of 290,104 (213,745-359,636) and 39,434 (30,782-47,084) deaths, respectively, and the weekly model underestimated these numbers by 8.56% and 21.56%. Importantly, differences were systematically smaller during extreme cold and heat periods, such as the summer of 2003, with an underestimation of only 4.62% in the weekly data model. We applied this framework to infer that the heat-related mortality burden during the year 2022 in Europe may have exceeded the 70,000 deaths.

Interpretation

The present work represents a first reference study validating the use of weekly time series as an approximation to the short-term effects of cold and heat on human mortality. This approach can be adopted to complement access-restricted data networks, and facilitate data access for research, translation and policy-making.

Funding

The study was supported by the ERC Consolidator Grant EARLY-ADAPT (https://www.early-adapt.eu/), and the ERC Proof-of-Concept Grants HHS-EWS and FORECAST-AIR.

[Influence of wind, cold and dampness on clinical manifestation of knee osteoarthritis patients based on the stratifications of traditional Chinese medicine constitution]

OBJECTIVE

To explore influence of external factors of wind, cold and dampness on clinical symptoms in knee osteoarthritis (KOA) patients with different constitutions of traditional Chinese medicine.

METHODS

A cross-sectional stratified study was performed to select 108 patients with GradeⅡKOA in Kellgren & Lawrence (K-L) classification, including 22 males and 86 females, aged from 47 to 75 years old with an average of (60.7±6.0) years old;body mass index(BMI) ranged from 17.87 to 31.22 kg·m-2 with an average of (23.80±2.86) kg·m-2. According to Classification and Judgment of TCM Physique (ZYYXH/T157-2009), the types of TCM physique were determined and divided into 4 layers according to the deficiency and actual physique. Among them, there were 24 patients without biased physique, 12 males and 12 females, aged from 51 to 73 years old with an average of(62.8±6.0) years old, BMI ranged from 17.87 to 31.14 kg·m-2 with an average of (24.32±3.25) kg·m-2;there were 46 patients with virtual bias constitution, including 7 males and 39 females, aged from 47 to 70 years old with an average of (60.0±5.8) years old, BMI ranged from 19.38 to 31.22 kg·m-2 with an average of(23.42±2.97) kg·m-2;There were 26 patients with solid bias constitution, including 2 males and 24 females, aged from 48 to 75 years old with an average of (60.4±5.8) years old, BMI ranged from 21.16 to 30.76 kg·m-2 with an average of (24.15±2.33) kg·m-2;there were 9 patients with special constitution, 1 male and 8 female, aged from 53 to 75 years old with an average of (59.8±7.5) years old, BMI ranged from 19.26 to 26.67 kg·m-2 with an average of (23.79±2.49) kg·m-2. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used to evaluate severity of clinical symptoms. The wind-cold-dampness external factor score was calculated through the questionnaire of wind-cold-dampness syndrome scale to evaluate degree of influence of wind-cold-dampness external factor. Pearson correlation analysis and partial correlation analysis were used to calculate the correlation coefficient between severity of external factors affecting wind, cold and dampness and severity of clinical symptoms in patients with different TCM constitution stratification.

RESULTS

There was no statistical significance between total score of wind-cold-dampness and WOMAC score in patients with no biased constitution and special condition. Total wind-cold-dampness score of patients with virtual biased constitution was positively correlated with WOMAC stiffness score (r=0.327, P=0.032), and total wind-cold-dampness score of patients with solid biased constitution was positively correlated with WOMAC pain score (r=0.561, P=0.005) and WOMAC overall score (r=0.446, P=0.033). After further adjusting for the interaction of external factors of wind-cold-dampness, there was no statistical significance between wind-cold-dampness scores and WOMAC scores in patients with solid biased constitution. The score of dampness and pathogenic factors was positively correlated with WOMAC stiffness score (r=0.414, P=0.007).

CONCLUSION

The external factors of wind-cold dampness have different effects on the clinical symptoms of KOA patients with different TCM constitutions. Compared with other constitutions, the rigid symptoms of patients with asthenic biased constitutions are more susceptible to dampness pathogenic factors.

Rapture of the deep: gas narcosis may impair decision-making in scuba divers

Introduction

While gas narcosis is familiar to most divers conducting deep (> 30 metres) dives, its effects are often considered minuscule or subtle at 30 metres. However, previous studies have shown that narcosis may affect divers at depths usually considered safe from its influence, but little knowledge exists on the effects of gas narcosis on higher cognitive functions such as decision-making in relatively shallow water at 30 metres. Impaired decision-making could be a significant safety issue for a multitasking diver.

Methods

We conducted a study exploring the effects of gas narcosis on decision-making in divers breathing compressed air underwater. The divers (n = 22) were evenly divided into 5-metre and 30-metre groups. In the water, we used underwater tablets equipped with the Iowa Gambling Task (IGT), a well-known psychological task used to evaluate impairment in decision-making.

Results

The divers at 30 metres achieved a lower score (mean 1,584.5, standard deviation 436.7) in the IGT than the divers at 5 metres (mean 2,062.5, standard deviation 584.1). Age, body mass index, gender, or the number of previous dives did not affect performance in the IGT.

Conclusions

Our results suggest that gas narcosis may affect decision-making in scuba divers at 30 metres depth. This supports previous studies showing that gas narcosis is present at relatively shallow depths and shows that it may affect higher cognitive functions.

Projection of extreme heat- and cold-related mortality in Sweden based on the spatial synoptic classification

BACKGROUND

Climate change is projected to result in increased heat events and decreased cold events. This will substantially impact human health, particularly when compounded with demographic change. This study employed the Spatial Synoptic Classification (SSC) to categorize daily weather into one of seven types. Here we estimated future mortality due to extremely hot and cold weather types under different climate change scenarios for one southern (Stockholm) and one northern (Jämtland) Swedish region.

METHODS

Time-series Poisson regression with distributed lags was used to assess the relationship between extremely hot and cold weather events and daily deaths in the population above 65 years, with cumulative effects (6 days in summer, 28 days in winter), 1991 to 2014. A global climate model (MPI-M-MPI-ESM-LR) and two climate change scenarios (RCP 4.5 and 8.5) were used to project the occurrence of hot and cold days from 2031 to 2070. Place-specific projected mortality was calculated to derive attributable numbers and attributable fractions (AF) of heat- and cold-related deaths.

RESULTS

In Stockholm, for the RCP 4.5 scenario, the mean number of annual deaths attributed to heat increased from 48.7 (CI 32.2-64.2; AF = 0.68%) in 2031-2040 to 90.2 (56.7-120.5; AF = 0.97%) in 2061-2070, respectively. For RCP 8.5, heat-related deaths increased more drastically from 52.1 (33.6-69.7; AF = 0.72%) to 126.4 (68.7-175.8; AF = 1.36%) between the first and the last decade. Cold-related deaths slightly increased over the projected period in both scenarios. In Jämtland, projections showed a small decrease in cold-related deaths but no change in heat-related mortality.

CONCLUSIONS

In rural northern region of Sweden, a decrease of cold-related deaths represents the dominant trend. In urban southern locations, on the other hand, an increase of heat-related mortality is to be expected. With an increasing elderly population, heat-related mortality will outweigh cold-related mortality at least under the RCP 8.5 scenario, requiring societal adaptation measures.

Non-coding RNAs (ncRNAs) in plant: Master regulators for adapting to extreme temperature conditions

Unusual daily temperature fluctuations caused by climate change and climate variability adversely impact agricultural crop production. Since plants are immobile and constantly receive external environmental signals, such as extreme high (heat) and low (cold) temperatures, they have developed complex molecular regulatory mechanisms to cope with stressful situations to sustain their natural growth and development. Among these mechanisms, non-coding RNAs (ncRNAs), particularly microRNAs (miRNAs), small-interfering RNAs (siRNAs), and long-non-coding RNAs (lncRNAs), play a significant role in enhancing heat and cold stress tolerance. This review explores the pivotal findings related to miRNAs, siRNAs, and lncRNAs, elucidating how they functionally regulate plant adaptation to extreme temperatures. In addition, this review addresses the challenges associated with uncovering these non-coding RNAs and understanding their roles in orchestrating heat and cold tolerance in plants.

Molecular mechanisms of SNAC1 (Stress-responsive NAC1) in conferring the abiotic stress tolerance

NAC family gene - SNAC1 (Stress-responsive NAC1) is responsive to drought, salt, cold stress, and ABA. It acts as a regulator in mediating tolerance to abiotic stress through different pathways. Abiotic stress, among them drought and salinity, are adverse factors for plant growth and crop productivity. SNAC1 was an object of high interest according to the effect of improved drought and salt tolerance when overexpressed in different plant species such as rice, wheat, barley, cotton, maize, banana, or oat. SNAC1 functions by regulating the expression of genes that contain the NAC Recognized Sequence (NACRS) within their promoter region. This gene is induced by drought, specifically in guard cells. Its downstream targets have been identified. The role of SNAC1 in molecular and physiological responses during abiotic stress has been proposed, but this knowledge still needs to be expanded. Here, we describe recent advances in understanding the action of SNAC1 in adapting plants to abiotic stress.

To the extreme! How biological anthropology can inform exercise physiology in extreme environments

The fields of biological anthropology and exercise physiology are closely related and can provide mutually beneficial insights into human performance. These fields often use similar methods and are both interested in how humans function, perform, and respond in extreme environments. However, these two fields have different perspectives, ask different questions, and work within different theoretical frameworks and timescales. Biological anthropologists and exercise physiologists can greatly benefit from working together when examining human adaptation, acclimatization, and athletic performance in the extremes of heat, cold, and high-altitude. Here we review the adaptations and acclimatizations in these three different extreme environments. We then examine how this work has informed and built upon exercise physiology research on human performance. Finally, we present an agenda for moving forward, hopefully, with these two fields working more closely together to produce innovative research that improves our holistic understanding of human performance capacities informed by evolutionary theory, modern human acclimatization, and the desire to produce immediate and direct benefits.

Association of low and high ambient temperature with mortality for cardiorespiratory diseases in Brazil

Extreme temperatures are a major public health concern, as they have been linked to an increased risk of mortality from circulatory and respiratory diseases. Brazil, a country with vast geographic and climatic variations, is particularly vulnerable to the health impacts of extreme temperatures. In this study, we examined the nationwide (considering 5572 municipalities) association of low and high ambient temperature (1st and 99th percentiles) with daily mortality for circulatory and respiratory diseases in Brazil between 2003 and 2017. We used an extension of the two-stage time-series design. First, we applied a case time series design in combination with distributed lag non-linear modeling (DLMN) framework to assess the association by Brazilian region. Here, the analyses were stratified by sex, age group (15-45, 46-65, and >65 years), and cause of death (respiratory and circulatory mortality). In the second stage, we performed a meta-analysis to estimate pooled effects across the Brazilian regions. Our study population included 1,071,090 death records due to cardiorespiratory diseases in Brazil over the study period. We found increased risk of respiratory and circulatory mortality associated with low and high ambient temperatures. The pooled national results for the whole population (all ages and sex) suggest a relative risk (RR) of 1.27 (95% CI: 1.16; 1.37) and 1.11 (95% CI: 1.01; 1.21) associated with circulatory mortality during cold and heat exposure, respectively. For respiratory mortality, we estimated a RR of 1.16 (95% CI: 1.08; 1.25) during cold exposure and a RR of 1.14 (95% CI: 0.99; 1.28) during heat exposure. The national meta-analysis indicated robust positive associations for circulatory mortality on cold days across several subgroups by sex and age, while only a few subgroups presented robust positive associations for circulatory mortality on warm days and respiratory mortality on both cold and warm days. These findings have important public health implications for Brazil and suggest the need for targeted interventions to mitigate the adverse effects of extreme temperatures on human health.

Cold-water immersion and whole-body cryotherapy attenuate muscle soreness during 3 days of match-like tennis protocol

PURPOSE

This study aimed to investigate the effect of whole-body cryotherapy (WBC), cold-water immersion (CWI) and passive recovery (PAS) on tennis recovery.

METHODS

Thirteen competitive male tennis players completed three consecutive match-like tennis protocols, followed by recovery (WBC, CWI, PAS) in a crossover design. Five tennis drills and serves were performed using a ball machine to standardize the fatiguing protocol. Maximal voluntary contraction (MVC) peak torque, creatine kinase activity (CK), muscle soreness, ball accuracy and velocity together with voluntary activation, low- and high-frequency torque and EMG activity were recorded before each protocol and 24 h following the third protocol.

RESULTS

MVC peak torque (- 7.7 ± 11.3%; p = 0.001) and the high- to low-frequency torque ratio (- 10.0 ± 25.8%; p < 0.05) decreased on Day 1 but returned to baseline on Day 2, Day 3 and Day 4 (p = 0.052, all p > 0.06). The CK activity slightly increased from 161.0 ± 100.2 to 226.0 ± 106.7 UA L-1 on Day 1 (p = 0.001) and stayed at this level (p = 0.016) across days with no differences between recovery interventions. Muscle soreness increased across days with PAS recovery (p = 0.005), while no main effect of time was neither observed with WBC nor CWI (all p > 0.292). The technical performance was maintained across protocols with WBC and PAS, while it increased for CWI on Day 3 vs Day 1 (p = 0.017).

CONCLUSION

Our 1.5-h tennis protocol led to mild muscle damage, though neither the neuromuscular function nor the tennis performance was altered due to accumulated workload induced by consecutive tennis protocols. The muscle soreness resulting from tennis protocols was similarly alleviated by both CWI and WBC.

TRIAL REGISTRATION

IRB No. 2017-A02255-48, 12/05/2017.

Cardiorespiratory physiology and swimming capacity of Atlantic salmon (Salmo salar) at cold temperatures

We investigated how acclimation to 8, 4 and 1°C, and acute cooling from 8  to 1°C, affected the Atlantic salmon's aerobic and anaerobic metabolism, and cardiac function, during a critical swim speed (Ucrit) test. This study revealed several interesting temperature-dependent effects. First, while differences in resting heart rate (fH) between groups were predictable based on previous research (range ∼28-65 beats  min-1), with values for 1°C-acclimated fish slightly higher than those of acutely exposed conspecifics, the resting cardiac output () of 1°C-acclimated fish was much lower and compensated for by a higher resting blood oxygen extraction (ṀO2/). In contrast, the acutely exposed fish had a ∼2-fold greater resting stroke volume (VS) compared with that of the other groups. Second, increases in fH (1.2- to 1.4-fold) contributed little to during the Ucrit test, and the contributions of (VS) versus ṀO2/ to aerobic scope (AS) were very different in the two groups tested at 1°C (1°C-acclimated and 8-1°C fish). Finally, Ucrit was 2.08 and 1.69 body lengths (BL) s-1 in the 8 and 4°C-acclimated groups, but only 1.27 and 1.44 BL s-1 in the 1°C-acclimated and 8-1°C fish, respectively - this lower value in 1°C versus 8-1°C fish despite higher values for maximum metabolic rate and AS. These data: support recent studies which suggest that the capacity to increase fH is constrained at low temperatures; show that cardiorespiratory function at cold temperatures, and its response to increased demands, depends on exposure duration; and suggest that AS does not constrain swimming capacity in salmon when chronically exposed to temperatures approaching their lower limit.

Seven plant capacities to adapt to abiotic stress

Abiotic stresses such as drought and heat continue to impact crop production in a warming world. This review distinguishes seven inherent capacities that enable plants to respond to abiotic stresses and continue growing, although at a reduced rate, to achieve a productive yield. These are the capacities to selectively take up essential resources, store them and supply them to different plant parts, generate the energy required for cellular functions, conduct repairs to maintain plant tissues, communicate between plant parts, manage existing structural assets in the face of changed circumstances, and shape-shift through development to be efficient in different environments. By illustration, we show how all seven plant capacities are important for reproductive success of major crop species during drought, salinity, temperature extremes, flooding, and nutrient stress. Confusion about the term 'oxidative stress' is explained. This allows us to focus on the strategies that enhance plant adaptation by identifying key responses that can be targets for plant breeding.

Low ambient temperature and hospitalization for cardiorespiratory diseases in Brazil

Studies have shown that larger temperature-related health impacts may be associated with cold rather than with hot temperatures. Although it remains unclear the cold-related health burden in warmer regions, in particular at the national level in Brazil. We address this gap by examining the association between low ambient temperature and daily hospital admissions for cardiovascular and respiratory diseases in Brazil between 2008 and 2018. We first applied a case time series design in combination with distributed lag non-linear modeling (DLNM) framework to assess the association of low ambient temperature with daily hospital admissions by Brazilian region. Here, we also stratified the analyses by sex, age group (15-45, 46-65, and >65 years), and cause (respiratory and cardiovascular hospital admissions). In the second stage, we performed a meta-analysis to estimate pooled effects across the Brazilian regions. Our sample included more than 23 million hospitalizations for cardiovascular and respiratory diseases nationwide between 2008 and 2018, of which 53% were admissions for respiratory diseases and 47% for cardiovascular diseases. Our findings suggest that low temperatures are associated with a relative risk of 1.17 (95% CI: 1.07; 1.27) and 1.07 (95% CI: 1.01; 1.14) for cardiovascular and respiratory admissions in Brazil, respectively. The pooled national results indicate robust positive associations for cardiovascular and respiratory hospital admissions in most of the subgroup analyses. In particular, for cardiovascular hospital admissions, men and older adults (>65 years old) were slightly more impacted by cold exposure. For respiratory admissions, the results did not indicate differences among the population groups by sex and age. This study can help decision-makers to create adaptive measures to protect public health from the effects of cold temperature.

Biological function research of Fusarium oxysporum f. sp. cubense inducible banana long noncoding RNA Malnc2310 in Arabidopsis

Long noncoding RNAs (lncRNAs) participate in plant biological processes under biotic and abiotic stresses. However, little is known about the function and regulation mechanism of lncRNAs related to the pathogen at a molecular level. A banana lncRNA, Malnc2310, is a Fusarium oxysporum f. sp. cubense inducible lncRNA in roots. In this study, we demonstrate the nuclear localization of Malnc2310 by fluorescence in situ hybridization and it can bind to several proteins that are related to flavonoid pathway, pathogen response and programmed cell death. Overexpression of Malnc2310 increases susceptibility to Fusarium crude extract (Fu), salinity, and cold in transgenic Arabidopsis. In addition, Malnc2310 transgenic Arabidopsis accumulated more anthocyanins under Fusarium crude extract and cold treatments that are related to upregulation of these genes involved in anthocyanin biosynthesis. Based on our findings, we propose that Malnc2310 may participate in flavonoid metabolism in plants under stress. Furthermore, phenylalanine ammonia lyase (PAL) protein expression was enhanced in Malnc2310 overexpressed transgenic Arabidopsis, and Malnc2310 may participate in PAL regulation by binding to it. This study provides new insights into the role of Malnc2310 in mediating plant stress adaptation.

Climate and human mortality in Virginia, 2005-2020

Using an extensive database of every resident death in Virginia from 2005 to 2020, climate-mortality relationships are examined for 12 climatically homogeneous regions within the Commonwealth. Each region is represented by a first-order weather station from which archived temperature and humidity data are used to generate a variety of biometeorologically relevant indices. Using these indices and other variables (such as air quality and heat and cold waves), daily mortality and climate relationships are modeled for each region over a 21-day lag period utilizing generalized additive models and distributed lag non-linear models. Optimal models are identified for each region, and a consensus model was also run based on maximum temperature to facilitate inter-regional comparisons. The relative risk of mortality varies markedly as a function of climate between regions, with U-shaped, J-shaped, and inverse linear relationships evident. Cold mortality exceeds heat mortality across most of Virginia (typical relative risks are 1.10 for cold and 1.03 for heat), with cold risks strongest at lags 3 to 10. Low temperatures (or low humidity) are protective at lags 0-2 days except in the colder, western parts of state. Heat mortality occurs at short lags (0-2 days) for three-fourths of the stations, but the spatial pattern is random. Mortality displacement is evident for most regions for several days following the heat-related spike. Although the use of region-specific models is justified, the simple consensus model based on a consistent set of predictors provides similar results.

Data of germination ability of tetraploid rice lines under multiple stress factors

Rice production is affected by several environmental factors, such as cold, salinity and drought stress. These unfavourable factors could have a serious impact on germination as well as on later growth, causing many types of damage. Recently, polyploid breeding can offer an alternative opportunity to enhance the yield and abiotic stress tolerance in rice breeding. This article describes some germination parameters of 11 different autotetraploid breeding lines and their parental lines under different environmental stresses. Each genotype was grown in a climate chamber under controlled conditions: 13 °C for 4 weeks in the cold test and 30/25 °C for 5 days in control, salinity (150 mM NaCl) and drought (15% PEG 6000) treatments, respectively. The germination process was monitored throughout the experiment. The average data were calculated using three replicates. This dataset contains germination raw data and three calculated germination parameters, such as median germination time (MGT), final germination percentage (FGP), and germination index (GI). These data may provide reliable support to clarify whether the tetraploid lines can exceed the performance of their diploid parental lines under germination phase or not.

Genome-wide identification and functional analysis of ICE genes reveal that Gossypium thurberi "GthICE2" is responsible for cold and drought stress tolerance

Cold stress has been found to have a negative impact on cotton growth and annual production. To address this issue, the utilization of cold-tolerant gene resources from wild species of Gossypium is crucial for genetic improvements in cultivated cotton. ICE (inducer of CBF expression) are the key regulators of cold tolerance in plants, however, there is relatively little information on ICE genes in cotton. Herein, we performed comprehensive bioinformatics analyses of the ICE gene family in eight cotton species. Phylogenetic analysis showed that 52 ICE genes were clustered into four subgroups. Cis-regulatory elements analysis suggests that the expression of ICE genes might be regulated by light, plant hormones, and various environment stresses. Higher expression of GthICE2 was observed in leaves as compared to roots and stems, in response to cold, drought, and exogenous hormone ABA. Furthermore, overexpression of GthICE2 in A. thaliana led to higher germination and survival rates, longer root length, lower ion leakage, and induction under cold and drought stress. Histochemical staining showed that oxidative damage in transgenic lines was much lower compared to wild-type plants. Lower MDA contents and higher SOD and POD activities were observed in overexpressed plants. Y1H and LUC assays revealed that GthICE2 might activate the expression of GthCBF4, a cold-responsive gene, by connecting with the MYC cis-element present in the promoter of GthCBF4. GthICE2 confers cold and drought stress tolerance in cotton. Our findings add significantly to the existing knowledge regarding cold stress tolerance and helps to elucidate cold response mechanisms in cotton.

Genome-wide identification and expression analysis of the Pisum sativum (L.) APETALA2/ethylene-responsive factor (AP2/ERF) gene family reveals functions in drought and cold stresses

AP2/ERF (APETALA2/Ethylene Response Factor) is a family of transcription factors that play essential roles in regulating gene expression in response to various environmental stimuli, including biotic and abiotic stresses, hormone signaling, and developmental processes. Pisum sativum (L.), commonly known as garden pea, is a winter crop sensitive to high temperatures and can also be affected by extreme cold and drought conditions. This study performed a genome-wide analysis of AP2/ERF genes and identified 153 AP2/ERF genes in P. sativum. Based on the conserved AP2/ERF domain and sequence homology, they were classified into AP2 (APETALA2), ERF (Ethylene Response Factor), DREB (Dehydration responsive element-binding), RAV (Related to Abscisic Acid Insensitive 3/ Viviparous 1) and Soloist subfamily. The DREB and ERF subfamily were further divided into groups A1-6 and B1-B6. Tandem and segmental duplication events were more frequent in the ERF subfamily, which can have important implications for their evolution and functional diversification. Under cold stress, the expression of DREB1A was highly induced in leaves, whereas DREB1B was suppressed. Similarly, the DREB2A, DREB2C, DREB2E, and DREB2F were induced in leaves under drought stress. The putative target genes of AP2/ERF transcription factors are highly diversified, suggesting that they play essential roles in various physiological responses in plants, including responses to biotic and abiotic stresses as well as developmental processes. Thus, this study of AP2/ERF genes and their functions provides valuable insight into how P. sativum responds to different environmental conditions, including cold and drought stresses.

Effects of gestational ambient extreme temperature exposures on the risk of preterm birth in China: A sibling-matched study based on a multi-center prospective cohort

BACKGROUND

Previous epidemiological findings on extreme temperature and preterm birth (PTB) were heterogeneous, especially for extreme cold exposure. Measured and unmeasured individual-level factors such as genetic factors or lifecourse exposures may constitute important contributors but have not been addressed.

OBJECTIVES

We aimed to examine the association of gestational heat and cold exposure with PTB using a novel sibling-matched study.

METHODS

Based on a multi-center population-based birth cohort across 16 counties in China, we included 10,826 sibling pairs born from March 2013 to December 2018. Conditional logistic and Cox Proportional Hazard regression models were used to estimate the effects of heat and cold exposure on PTB in each trimester, one and four weeks before delivery and the entire pregnancy. We also tested the heterogeneity in the association of temperature with PTB between siblings.

FINDINGS

Exposure to heat during the third trimester and the entire pregnancy increased the risk of PTB. For heat (> 90th) defined with mean temperature, the odds ratios were 2.32 (1.63, 3.30) and 3.19 (2.22, 4.58), respectively. Cold exposure (< 10th) during the first, the third, and the entire pregnancy was associated with a higher PTB risk, with ORs (95%CIs) of 2.04 (1.43, 2.90), 3.13 (2.14, 4.58), and 4.26 (2.94, 6.19), respectively. We found slightly stronger associations of heat exposure during the entire pregnancy with the firstborn PTB, and stronger associations of cold exposure during one week and four weeks before delivery with secondborn PTB.

CONCLUSIONS

Using a sibling-matched study, we took into account some mother-level unobserved confounding. Our research strengthens the evidence that gestational exposure to heat and cold increases the risk of PTB. Our findings may have important implications for improving the health of newborns in the context of climate change.

Lethal and sublethal implications of low temperature exposure for three intertidal predators

Benthic invertebrate predators play a key role in top-down trophic regulation in intertidal ecosystems. While the physiological and ecological consequences of predator exposure to high temperatures during summer low tides are increasingly well-studied, the effects of cold exposure during winter low tides remain poorly understood. To address this knowledge gap, we measured the supercooling points, survival, and feeding rates of three intertidal predator species in British Columbia, Canada - the sea stars Pisaster ochraceus and Evasterias troschelii and the dogwhelk Nucella lamellosa - in response to exposure to sub-zero air temperatures. Overall, we found that all three predators exhibited evidence of internal freezing at relatively mild sub-zero temperatures, with sea stars exhibiting an average supercooling point of -2.50 °C, and the dogwhelk averaging approximately -3.99 °C. None of the tested species are strongly freeze tolerant, as evidenced by moderate-to-low survival rates after exposure to -8 °C air. All three predators exhibited significantly reduced feeding rates over a two-week period following a single 3-h sublethal (-0.5 °C) exposure event. We also quantified variation in predator body temperature among thermal microhabitats during winter low tides. Predators that were found at the base of large boulders, on the sediment, and within crevices had higher body temperatures during winter low tides, as compared to those situated in other microhabitats. However, we did not find evidence of behavioural thermoregulation via selective microhabitat use during cold weather. Since these intertidal predators are less freeze tolerant than their preferred prey, winter low temperature exposures can have important implications for organism survival and predator-prey dynamics across thermal gradients at both local (habitat-driven) and geographic (climate-driven) scales.

Changes in the temperature-mortality relationship in France: Limited evidence of adaptation to a new climate

CONTEXT

Documenting trends in the health impacts of ambient temperature is key to supporting adaptation strategies to climate change. This paper explores changes in the temperature-related mortality in 18 French urban centers between 1970 and 2015.

METHOD

A multicentric time-series design with time-varying distributed lag nonlinear models was adopted to model the shape of the relationship and assess temporal changes in risks and impacts.

RESULTS

The general shape of the temperature-mortality relationship did not change over time, except for an increasing risk at very low percentiles and a decreasing risk at very high percentiles. The relative risk at the 99.9^th percentile compared to the 50^th percentile of the 1970-2015 temperature distribution decreased from 2.33 [95% confidence interval (CI): 1.95:2.79] in 1975 to 1.33 [95% CI: 1.14:1.55] in 2015. Between 1970 and 2015, 302,456 [95% CI: 292,723:311,392] deaths were attributable to non-optimal temperatures, corresponding to 5.5% [95% CI: 5.3:5.6] of total mortality. This burden decreased progressively, representing 7.2% [95% CI: 6.7:7.7] of total mortality in the 1970s to 3.4% [95% CI: 3.2:3.6] in the 2000s. However, the contribution of hot temperatures to this burden (higher than the 90^th percentile) increased.

DISCUSSION

Despite the decreasing relative risk, the fraction of mortality attributable to extreme heat increased between 1970 and 2015, thus highlighting the need for proactive adaptation.

Ambient temperature and nervous system diseases-related mortality in Japan from 2010 to 2019: A time-stratified case-crossover analysis

BACKGROUND

Despite the substantial disease burden caused by nervous system diseases, few studies have examined the association between ambient temperature and nervous system diseases, especially during cold seasons. Evidence for specific disease subgroups such as Alzheimer's and Parkinson's is also lacking.

OBJECTIVES

This study examined the association between short-term changes in ambient temperature and nervous system diseases-related mortality in ten Japanese prefectures from 1 January 2010 to 31 December 2019.

METHODS

A two-stage analysis based on a time-stratified case-crossover study design was conducted. A conditional quasi-Poisson regression model with a distributed lag non-linear model for temperature was applied followed by a multivariate random-effects meta-analysis to obtain average associations. Mortality due to all and cause-specific nervous system diseases (major neurodegenerative diseases, Alzheimer's, and Parkinson's) were analyzed, with consideration for sex and age (0-84 and 85+ years old) subgroups.

RESULTS

We analyzed 162,315 death cases due to nervous system diseases. Cold was associated with all categories of nervous system diseases-related mortality, but not heat. The estimated relative risks for cold, obtained by comparing the 2.5th percentile of daily mean temperature distribution to the minimum mortality temperature (MMT), were 1.43 (95 % CI: 1.28-1.60), 1.37 (95 % CI: 1.17-1.59), 1.53 (95 % CI: 1.07-2.01), and 1.54 (95 % CI: 1.13-2.10) for all nervous system diseases, major neurodegenerative diseases, Alzheimer's, and Parkinson's, respectively. These associations were also observed in the sex and age subgroups in general but without evidence of effect modification. Heat (the 97.5th percentile of daily mean temperature distribution vs. MMT) was associated with Parkinson's disease-related mortality among those aged 85 years and over.

DISCUSSION

Cold was associated with an increased risk of nervous system disease-related mortality. The effect of heat was not observed, except for mortality among the elderly aged 85 years and older with Parkinson's disease.

Identifying the critical windows and joint effects of temperature and PM2.5 exposure on small for gestational age

The potential critical windows for extreme ambient temperature, air pollution exposure and small for gestational age (SGA) are still unclear, and no study has explored their joint effects on SGA. In a national multi-center prospective cohort, we included 179,761 pairs of mother-infant from 16 counties of 8 provinces in China during 2014-2018. Daily averaged temperature and PM2.5 concentration were matched to the maternal residential address to estimate personal exposure. Extreme temperature exposures were categorized by a series of percentile in each meteorological and geographic division for the entire pregnancy, each trimester and gestational week (GA-week). Generalized linear mixed models (GLMMs) and distributed lag nonlinear models (DLNMs) were used to estimate the whole pregnancy-, trimester-specific, and weekly-specific associations of extreme temperature and PM2.5 exposures with SGA. Combined effects were evaluated with the relative excess risk due to interaction (RERI) and proportion attributable to interaction (AP). We observed that by referring to temperature at the 41st - 50th percentile, heat (>90th percentile) exposure during 13th - 29th GA-weeks was associated with SGA; odds ratio (OR) and 95 % confidence intervals (CI) was 1.16 (1.06, 1.28). For cold (<=10th percentile), inverse associations were observed during the 1st - 8th GA-weeks. PM2.5 exposure during the 2nd - 5th and 19th - 27th GA-weeks was associated with SGA, with the strongest association in the 2nd GA-week (OR = 1.0017, 95 %CI: 1.0001, 1.0034, for a 10 μg/m3 increase). No interactive effects between ambient temperature and PM2.5 on SGA were observed. Our findings suggest the weekly susceptibility windows for heat and PM2.5 exposure were primarily the gestational weeks within the 2nd trimester, therefore, corresponding protective measures should be conveyed to pregnant women during routine prenatal visits to reduce exposures.

Abnormal ambient temperature change increases the risk of out-of-hospital cardiac arrest: A systematic review and meta-analysis of exposure types, risk, and vulnerable populations

BACKGROUND

There is growing evidence in support of a short-term association between ambient temperature and cardiac arrest attacks that is a serious manifestation of cardiovascular disease and has a high incidence and low survival rate. However, it remains unrecognized about the hazardous temperature exposure types, exposure risk magnitude, and vulnerable populations.

OBJECTIVES

We comprehensively summarize prior epidemiological studies looking at the short-term associations of out-of-hospital cardiac arrest (OHCA) with various temperature exposures among different populations.

METHODS

We searched PubMed and Web of Science databases from inception to October 2021 for eligible English language. Temperature exposure was categorized into three types: heat (included high temperature, extreme heat, and heatwave), cold (included low temperature and extreme cold), and temperature variation (included diurnal temperature range and temperature change between two adjacent days). Meta-analysis weighted by inverse variance was used to pool effect estimates.

RESULTS

This study included 15 studies from 8 countries, totaling around 1 million OHCA events. Extreme heat and extreme cold were significantly associated with an increased risk of OHCA, and the pooled relative risks (RRs) were 1.071 [95 % confidence interval (CI): 1.019-1.126] and 1.662 (95%CI: 1.138-2.427), respectively. The risk of OHCA was also elevated by heatwaves (RR = 1.248, 95%CI: 1.091-1.427) and more intensive heatwaves had a greater effect. Notably, the elderly and males seemed to be more vulnerable to the effects of heat and cold. However, we did not observe a significant association between temperature variation and the risk of OHCA (1.005, 95%CI: 0.999-1.012).

CONCLUSION

Short-term exposure to heat and cold may be novel risk factors for OHCA. Considering available studies in limited regions, the temperature effect on OHCA should be urgently confirmed in different regions.

The air-breathing Alaska blackfish (Dallia pectoralis) suppresses brain mitochondrial reactive oxygen species to survive cold hypoxic winters

The Alaska blackfish (Dallia pectoralis) is the only air-breathing fish in the Arctic. In the summer, a modified esophagus allows the fish to extract oxygen from the air, but this behavior is not possible in the winter because of ice and snow cover. The lack of oxygen (hypoxia) and near freezing temperatures in winter is expected to severely compromise metabolism, and yet remarkably, overwintering Alaska blackfish remain active. To maintain energy balance in the brain and limit the accumulation of reactive oxygen species (ROS), we hypothesized that cold hypoxic conditions would trigger brain mitochondrial remodeling in the Alaska blackfish. To address this hypothesis, fish were acclimated to warm (15 °C) normoxia, cold (5 °C) normoxia or cold hypoxia (5 °C, 2.1-4.2 kPa; no air access) for 5-8 weeks. Mitochondrial respiration, ADP affinity and H₂0₂ production were measured at 10 °C in isolated brain homogenates with an Oroboros respirometer. Cold acclimation and chronic hypoxia had no effects on mitochondrial aerobic capacity or ADP affinity. However, cold acclimation in normoxia led to a suppression of brain mitochondrial H₂0₂ production, which persisted and became more pronounced in the cold hypoxic fish. Overall, our study suggests cold acclimation supresses ROS production in Alaska blackfish, which may protect the fish from oxidative stress when oxygen becomes limited during winter.

A novel method to selectively elicit cold sensations without touch

BACKGROUND

Thermal and tactile stimuli are transduced by different receptor classes. However, mechano- and thermo-sensitive afferents interact at spinal and supraspinal levels. Yet, most studies on responses to cooling stimuli are confounded by mechanical contact, making these interactions difficult to isolate. Methods for precise control of non-mechanical thermal stimulations remain challenging, particularly in the cold range.

NEW METHOD

We developed a non-tactile, focal, temperature-controlled, multi-purpose cooling stimulator. This method controls the exposure of a target skin region to a dry-ice source. Using a thermal camera to monitor skin temperature, and adjusting the source-skin distance accordingly, we could deliver non-tactile cooling stimuli with customisable profiles, for studying different aspects of cold sensation.

RESULTS

To validate our method, we measured absolute and relative thresholds for cold sensation without mechanical contact in 13 human volunteer participants, using the method of limits. We found that the absolute cold detection threshold was 32.71 ^oC ± 0.88 ^oC. This corresponded to a threshold relative to each participant's baseline skin temperature of - 1.08 ^oC ± 0.37 ^oC.

COMPARISONS WITH EXISTING METHOD

Our method allows cooling stimulation without the confound of mechanical contact, in a controllable and focal manner.

CONCLUSIONS

We report a non-contact cooling stimulator and accompanying control system. We used this to measure cold thresholds in the absence of confounding touch. Our method enables more targeted studies of both cold sensory pathways, and of cold-touch interactions.

Factors affecting outdoor physical activity in extreme temperatures in a sub-tropical Chinese urban population: an exploratory telephone survey

BACKGROUND

Physical activity (PA) can be affected by extreme temperatures, however fewer studies have identified factors impacting this relationship. This study sought to identify factors associated with changes of outdoor PA during extreme cold/heat events in a sub-tropical Chinese urban population, including factors of sociodemographic, health conditions, temperature-related awareness and attitude, and protective behaviours.

METHODS

Two telephone surveys were conducted a week after extreme cold/heat events in 2016 and 2017 among a cohort of Hong Kong residents over age 15. Data was collected on self-reported changes in outdoor PA level during the periods of extreme temperatures, health status, comorbidities, sociodemographic, and temperature-related awareness, and behavioural variables. We conducted multivariable logistic regression analyses to assess predictors of change in outdoor PA over the two extreme temperature events.

RESULTS AND CONCLUSION

Among 435 participants (42.8% response rate), over a third of the participants reported decreased outdoor PA level in extreme temperature events, while 10% reported an increase in extreme heat. Self-reported cardiovascular diseases were associated with decreased PA level in extreme cold, while hypertension was associated with unchanged/increased PA level in extreme heat. These results suggest physical activity to be an important consideration in the understanding of climate change-and-health pathways and meriting further research.

Ambient temperature and risk of motor vehicle crashes: A countrywide analysis in Spain

BACKGROUND

Some studies have documented that cold or hot ambient temperatures increase the risk of motor vehicle crashes. However, the number of existing studies is still limited, especially for the effects of cold.

OBJECTIVES

To estimate the relationship between ambient temperatures and risk of motor vehicle crashes in Spain, and to estimate the same association when restricting to those crashes with driver performance-associated factors (namely distraction, fatigue, sleepiness or disease).

METHODS

We used data for the period 1993-2013. We conducted a time series analysis controlling for seasonality and trends and using the distributed lag nonlinear model framework to estimate nonlinear and delayed effects of up to 7 days. Analyses were conducted at the province level and combined using multivariate meta-analysis.

RESULTS

The study included 1,908,460 motor vehicle crashes, 37% of them with associated driver performance factors. The overall analysis showed that the risk of crashes increased almost linearly with temperature. The estimates of the cumulative effect of lags 0-7 when comparing the 99th percentile and the first percentile of temperature produced a relative risk (RR) of 1.15 (95% confidence interval (CI): 1.11, 1.20). The estimates were slightly higher when analyses were restricted to crashes with driver performance-associated factors (RR: 1.23, 95% CI: 1.17, 1.30). In some provinces that reached temperatures below 0 °C, an increased risk with cold temperatures was also observed. An added effect of both cold spell and heat wave periods was found only in the analysis of crashes with driver performance-associated factors (cold spells, RR: 1.029, 95% CI: 1.005, 1.053; heat waves, RR: 1.020, 95% CI: 1.002, 1.039).

CONCLUSIONS

The increase of temperature increased the risk of motor vehicle crashes in Spain. Measures aimed at reducing the influence of heat on the risk of motor vehicle crashes can have important benefits for public health.

Characteristics of wet perception during the static touch of moist paper by the index fingertip alongside thermal stimulus application

Several factors have been reported to affect the perception of wetness. In the present study, we aimed to examine how wet perception changes when the factors related to thermal and/or wetness stimuli are modulated. First, the percentage of participants experiencing wet perception among filter papers with different water contents (0.00, 3.75, 7.50, 11.25, 15.00, and 18.75 µg/cm², corresponding to 0.00, 0.18, 0.37, 0.55,0.73 and 0.91 µg/mm³) was evaluated during static touch by the right index finger pad. The stimulus temperature was maintained at 30 °C. Second, the wet perception of paper with a water content of 18.75 µg/cm² was evaluated at stimulus temperature of 20 °C, 25 °C, 30 °C, 35 °C, and 40 °C. In the first experiment, the percentage of participants experiencing wet perception elevated with the increasing water content; however, the percentage plateaued at 11.25 µg/cm² of water (68.1 ± 25.5%). In the second experiment, when the stimulus temperature was < 30 °C, the wet perception increased as the stimulation temperature decreased. However, the wet perception reached a plateau at a stimulation temperature ≥30 °C. Participants experienced wet perception more consistently as the water content increased when the stimulus temperature was 30 ˚C. The effect of temperature on wet perception was limited to the stimulus temperature of <30 °C at which cold sensation was induced. However, no clear relationship between stimulus temperature and wet perception was observed when the stimulus temperature was ≥30 ˚C at which warm/hot sensation was induced.

Starch parameters and short-term temperature fluctuations - Important but not yet in focus?

Plants are regularly challenged by unfavorable environmental conditions. As climate change continues, adverse situations such as drought, heat, and cold are expected to increase and become more severe. Most starchy crops are affected by such stresses. In recent years, researchers have made many new discoveries about starch metabolism in general and also on granule structure, including effects on starch following longer-term temperature stresses. However, in this study, we focus on short-term temperature stress on storage starch granule properties. Here our knowledge is less and it is likely that also short-term temperature stresses can affect various starch parameters. Therefore, we see a need for this type of analysis and discuss the matter in more detail and we conclude that a deeper knowledge particularly of starch granule parameters could allow targeted breeding of cultivars that exhibit different starch characteristics as a result of short-term stress. For these reasons, we are convinced that more comprehensive research on the effects of short-term temperature stress on starch granule characteristics is important, necessary, and timely.

StICE1 enhances plant cold tolerance by directly upregulating StLTI6A expression

Under cold conditions, StICE1 enhances plant cold tolerance by upregulating StLTI6A expression to maintain the cell membrane stability. Cold stress affects potato plants growth and development, crop productivity and quality. The ICE-CBF-COR regulatory cascade is the well-known pathway in response to cold stress in plants. ICE1, as a MYC-like bHLH transcription factor, can regulate the expressions of CBFs. However, whether ICE1 could regulate other genes still need to be explored. Our results showed that overexpressing ICE1 from potato in Arabidopsis thaliana could enhance plant cold tolerance. Under cold stress, overexpressed StICE1 in plants improved the stability of cell membrane, enhanced scavenging capacity of reactive oxygen species and increased expression levels of CBFs and COR genes. Furthermore, StICE1 could bind to the promoter of StLTI6A gene, which could maintain the stability of the cell membrane, to upregulate StLTI6A expression under cold conditions. Our findings revealed that StICE1 could directly regulate StLTI6A, CBF and COR genes expression to response to cold stress.

Why hibernate? Predator avoidance in the edible dormouse

We address the question of ultimate selective advantages of hibernation. Biologists generally seem to accept the notion that multiday torpor is primarily a response to adverse environmental conditions, namely cold climate and low food abundance. We closely examine hibernation, and its summer equivalent estivation, in the edible dormouse, Glis glis. We conclude that in this species, hibernation is not primarily driven by poor conditions. Dormice enter torpor with fat reserves in years that are unfavourable for reproduction but provide ample food supply for animals to sustain themselves and even gain body energy reserves. While staying in hibernacula below ground, hibernators have much higher chances of survival than during the active season. We think that dormice enter prolonged torpor predominantly to avoid predation, mainly nocturnal owls. Because estivation in summer is immediately followed by hibernation, this strategy requires a good body condition in terms of fat reserves. As dormice age, they encounter fewer occasions to reproduce when calorie-rich seeds are available late in the year, and phase advance the hibernation season. By early emergence from hibernation, the best territories can be occupied and the number of mates maximised. However, this advantage comes at the cost of increased predation pressure that is maximal in spring. We argue the predator avoidance is generally one of the primary reasons for hibernation, as increased perceived predation pressure leads to an enhanced torpor use. The edible dormouse may be just an example where this behaviour becomes most obvious, on the population level and across large areas.

Modulation of transient receptor potential (TRP) channels by plant derived substances used in over-the-counter cough and cold remedies

BACKGROUND

Upper respiratory tract infections (URTIs) impact all age groups and have a significant economic and social burden on society, worldwide. Most URTIs are mild and self-limiting, but due to the wide range of possible causative agents, including Rhinovirus (hRV), Adenovirus, Respiratory Syncytial Virus (RSV), Coronavirus and Influenza, there is no single and effective treatment. Over-the-counter (OTC) remedies, including traditional medicines and those containing plant derived substances, help to alleviate symptoms including inflammation, pain, fever and cough.

PURPOSE

This systematic review focuses on the role of the major plant derived substances in several OTC remedies used to treat cold symptoms, with a particular focus on the transient receptor potential (TRP) channels involved in pain and cough.

METHODS

Literature searches were done using Pubmed and Web of Science, with no date limitations, using the principles of the PRISMA statement. The search terms used were 'TRP channel AND plant compound', 'cough AND plant compound', 'cough AND TRP channels AND plant compound', 'cough AND P2X3 AND plant compound' and 'P2X3 AND plant compound' where plant compound represents menthol or camphor or eucalyptus or turpentine or thymol.

RESULTS

The literature reviewed showed that menthol activates TRPM8 and may inhibit respiratory reflexes reducing irritation and cough. Menthol has a bimodal action on TRPA1, but inhibition may have an analgesic effect. Eucalyptus also activates TRPM8 and inhibits TRPA1 whilst down regulating P2X3, aiding in the reduction of cough, pain and airway irritation. Camphor inhibits TRPA1 and the activation of TRPM8 may add to the effects of menthol. Activation of TRPV1 by camphor, may also have an analgesic effect.

CONCLUSIONS

The literature suggests that these plant derived substances have multifaceted actions and can interact with the TRP 'cough' receptors. The plant derived substances used in cough and cold medicines have the potential to target multiple symptoms experienced during a cold.

Isolation and characterization of wheat ice recrystallisation inhibition gene promoter involved in low temperature and methyl jasmonate responses

It is well known that plant growth, development, survival and geographical distribution are constrained by extreme climatic conditions, especially extreme low temperature. Under cold stress, cold-inducible promoters were identified as important molecular switches to transcriptionally regulate the initiation of genes associated with cold acclimation processes and enhance the adaptability of plants to cold stimulation. Wheat (Triticum aestivum L.) is one of the most dominating food crops in the world, and wheat crops are generally overwintering with strong cold resistance. Our previous study already proved that heterologous expression of wheat ice recrystallization inhibition (IRI) genes enhanced freezing tolerance in tobacco. However, the upstream regulatory mechanisms of TaIRI are ambiguous. In this study, the space-time specific expression of TaIRI genes in wheat was analyzed by quantitative real-time PCR (qRT-PCR), and results showed that the expression of TaIRI in all tissues was cold-induced and accelerate by exogenous methyl jasmonate (MeJA). Three promoters of TaIRI genes were isolated from wheat genome, and various 5'-deletion fragments of TaIRIp were integrated into β-glucuronidase (GUS) within vector pCAMBIA1301. The promoter activity of TaIRI genes was determined through transient expression system of tobacco and stable expression of Arabidopsis thaliana. Results revealed that the GUS activity were significantly strengthened by cold and MeJA treatments. This study will provide insights into elucidating the transcription-regulatory mechanism of IRI proteins responding to low temperature.

Can sacubitril/valsartan combination enhance browning more than coldness?

BACKGROUND

It is a growing importance to induce a new treatment approach to encourage weight loss but also to improve maintenance of lost weight. It has been shown that promotion of brown adipose tissue (BAT) function or acquisition of BAT characteristics in white adipose tissue (terms referred as "browning") can be protective against obesity.

MAIN TEXT

Amongst numerous established environmental influences on BAT activity, cold exposure is the best interested technique due to its not only effects on of BAT depots in proliferation process but also de novo differentiation of precursor cells via β-adrenergic receptor activation. A novel combination drug, sacubitril/valsartan, has been shown to be more efficient in reducing cardiovascular events and heart failure readmission compared to conventional therapy. Also, this combination of drugs increases the postprandial lipid oxidation contributing to energy expenditure, promotes lipolysis in adipocytes and reduces body weight. To date, there is no research examining potential of combined sacubitril/valsartan use to promote browning or mechanisms in the basis of this thermogenic process.

CONCLUSION

Due to the pronounced effects of cold and sacubitril/valsartan treatment on function and metabolism of BAT, the primary goal of further research should focused on investigation of the synergistic effects of the sacubitril/valsartan treatment at low temperature environmental conditions.

Cold exposure induces dynamic changes in circulating triacylglycerol species, which is dependent on intracellular lipolysis: A randomized cross-over trial

BACKGROUND

The application of cold exposure has emerged as an approach to enhance whole-body lipid catabolism. The global effect of cold exposure on the lipidome in humans has been reported with mixed results depending on intensity and duration of cold.

METHODS

This secondary study was based on data from a previous randomized cross-over trial (ClinicalTrials.gov ID: NCT03012113). We performed sequential lipidomic profiling in serum during 120 min cold exposure of human volunteers. Next, the intracellular lipolysis was blocked in mice (eighteen 10-week-old male wild-type mice C57BL/6J) using a small-molecule inhibitor of adipose triglyceride lipase (ATGL; Atglistatin), and mice were exposed to cold for a similar duration. The quantitative lipidomic profiling was assessed in-depth using the Lipidyzer platform.

FINDINGS

In humans, cold exposure gradually increased circulating free fatty acids reaching a maximum at 60 min, and transiently decreased total triacylglycerols (TAGs) only at 30 min. A broad range of TAG species was initially decreased, in particular unsaturated and polyunsaturated TAG species with ≤5 double bonds, while after 120 min a significant increase was observed for polyunsaturated TAG species with ≥6 double bonds in humans. The mechanistic study in mice revealed that the cold-induced increase in polyunsaturated TAGs was largely prevented by blocking adipose triglyceride lipase.

INTERPRETATION

We interpret these findings as that cold exposure feeds thermogenic tissues with TAG-derived fatty acids for combustion, resulting in a decrease of circulating TAG species, followed by increased hepatic production of polyunsaturated TAG species induced by liberation of free fatty acids stemming from adipose tissue.

FUNDING

This work was supported by the Netherlands CardioVascular Research Initiative: 'the Dutch Heart Foundation, Dutch Federation of University Medical Centers, the Netherlands Organisation for Health Research and Development and the Royal Netherlands Academy of Sciences' [CVON2017-20 GENIUS-II] to Patrick C.N. Rensen. Borja Martinez-Tellez is supported by individual postdoctoral grant from the Fundación Alfonso Martin Escudero and by a Maria Zambrano fellowship by the Ministerio de Universidades y la Unión Europea - NextGenerationEU (RR_C_2021_04). Lucas Jurado-Fasoli was supported by an individual pre-doctoral grant from the Spanish Ministry of Education (FPU19/01609) and with an Albert Renold Travel Fellowship from the European Foundation for the Study of Diabetes (EFSD). Martin Giera was partially supported by NWO XOmics project #184.034.019.

Harder, better, faster, stronger: Frost tolerance of Eucalyptus benthamii under cold acclimation

Eucalypts are the most planted hardwood trees worldwide because of their very rapid growth, exceptional wood quality and adaptability. However, most commercial species and derived hybrids are sensitive to frost, which remains as the largest obstacle to their introduction in warm/temperate climates. As evergreen species, Eucalypts have developed the ability to tolerate frost events based on physiological and molecular responses triggered by previous exposure to cold temperatures, globally named cold acclimation. To characterize the acclimation process in two species with different tolerance to frost, E. grandis (Eg) and E. benthamii (Eb), seedlings were exposed for different times to low temperatures. Frost tolerance was estimated in leaves by an electrolyte leakage assay, and metabolome and morpho-physiological changes studied and correlated to the observed acclimation responses. Eb showed higher basal frost tolerance and an earlier and stronger acclimation response to cold temperatures than in the frost sensitive Eg. Eb was able to modify several morpho-physiological parameters, with a restriction in plant height, leaf area and leaf fresh weight during acclimation. Metabolome characterization allowed us to differentiate species and strengthen our understanding of their acclimation response dynamics. Interestingly, Eb displayed an early phase of sugar accumulation followed by a rise of different metabolites with possible roles as osmolytes and antioxidants, that correlated to frost tolerance and may explain Eb higher capacity to acclimate. This novel approach has helped us to point to the main metabolic processes underlying the cold tolerance acquisition process in two relevant Eucalyptus species.

Excess out-of-hospital cardiac arrests due to ambient temperatures in South Korea from 2008 to 2018

Out-of-hospital cardiac arrest (OHCA) is a notable public health issue with negative outcomes, such as high mortality and aftereffects. Additionally, the adverse effects of extreme temperatures on health have become more important under climate change; however, few studies have investigated the relationship between temperature and OHCA. In this study, we examined the association between temperature and OHCA and its underlying risk factors. We conducted a two-stage time-series analysis using a Poisson regression model with a distributed lag non-linear model (DLNM) and meta-analysis, based on a nationwide dataset from South Korea (2008-2018). We found that 17.4% of excess OHCA was attributed to cold, while 0.9% was attributed to heat. Based on central estimates, excess OHCA attributed to cold were more prominent in the population with hypertension comorbidity (31.0%) than the populations with diabetes (24.3%) and heart disease (17.4%). Excess OHCA attributed to heat were larger in the populations with diabetes (2.7%) and heart disease comorbidity (2.7%) than the population with hypertension (1.2%) based on central estimates. Furthermore, the time-varying excess OHCA attributed to cold have decreased over time, and although those of heat did not show a certain pattern during the study period, there was a weak increasing tendency since 2011. In conclusion, we found that OHCAs were associated with temperature, and cold temperatures showed a greater impact than that of hot temperatures. The effects of cold and hot temperatures on OHCA were more evident in the populations with hypertension, diabetes, and heart diseases, compared to the general population. In addition, the impacts of heat on OHCA increased in recent years, while those of cold temperatures decreased. Our results provide scientific evidence for policymakers to mitigate the OHCA burden attributed to temperature.