Short-term Effects Of Temperature Research Articles

Effects of short-term exposures to lower air temperature and cold spells on myocardial infarction hospital admissions: a nationwide study in Sweden

Abstract Background Exposures to lower air temperature and cold spells have been associated with an increased risk of various diseases. However, the short-term effect of lower air temperature and cold spells on myocardial infarction (MI) remains incompletely understood. Purpose We aimed to evaluate the short-term effects of lower air temperature and cold spells on MI hospital admissions within the nationwide SWEDEHEART registry. Methods This population-based nationwide study included 120,380 MI cases admitted to hospitals in Sweden during the cold season (October to March) from 2005 to 2019. Daily mean air temperature was estimated at 1 km2 spatial resolution across Sweden using a three-stage machine learning approach and percentiles of daily temperatures experienced by individuals in the same municipality were employed as individual exposure indicators to account for potential geographic adaptation. Cold spells were defined as periods of at least two consecutive days with a daily mean temperature below the 10th percentile of the temperature distribution for each municipality. A time-stratified case-crossover design incorporating a conditional logistic regression model with distributed lag non-linear model using lag 0-1 and lag 2-6 days was employed to evaluate the short-term effects of lower air temperature and cold spells on total MI, non-ST-segment elevation MI (NSTEMI) and ST-segment elevation MI (STEMI). Results We found significant increases in risk for total MI, NSTEMI, and STEMI in association with a decrease of one percentile in temperature at a lag of 2-6 days, indicated by ORs (95% CI) of 1.099 (1.057-1.142), 1.110 (1.06-1.164), and 1.076 (1.004-1.153), respectively. Additionally, we found that cold spells were significantly associated with increased risks for total MI, NSTEMI, and STEMI at a lag of 2-6 days, with ORs (95% CI) of 1.077 (1.037-1.12), 1.069 (1.02-1.119), and 1.095 (1.023-1.172), respectively. Moreover, independent effects of lower air temperature and cold spells on MI occurrence were found after adjusting for each other. Conversely, we observed that lower air temperature and cold spells were associated with decreased risks for MI at a lag of 0-1 days. Conclusions This nationwide case-crossover study demonstrated a novel biphasic pattern in MI risk following exposure to lower air temperatures and cold spells, characterized by an initial transient reduction in risk at lags 0-1 day, followed by a significant increase in risk at lags 2-6 days. As climate change continues to induce complex shifts in regional weather patterns, enhancing protections to reduce future cold-related cardiac hospitalizations is crucial.

Evaluating the effects of short-term low temperature on the growth and development of Trichopria drosophilae based on the age–stage two-sex life table

BackgroundThe effects of low temperatures on parasitic wasps are crucial for maintaining farmland biodiversity and enhancing biological control, especially given the implications of global warming and frequent extreme cold events.MethodsWe studied the effects of different low temperatures (−8 ± 1 °C, −4 ± 1 °C, 0 ± 1 °C, 4 ± 1 °C, and 8 ± 1 °C) on the mating frequency and duration of male adults of Trichopria drosophilae and the number of pupae beaten by female adults, and constructed the age–stage two-sex life table of T. drosophilae.ResultsThis study found that male T. drosophilae adults exposed to low temperatures for 12 h significantly altered their mating behavior, peaking between 15:00 and 17:00. As the temperature dropped during the exposure, both the mating frequency of T. drosophilae and the duration of pupal beating were affected. The survival rate of female adults dropped from 39.55% at 8 °C to just 21.17% at −8 °C. Low-temperature treatment shortened the development period and lifespan for T. drosophilae adults. They developed 4.71 days faster and had a total lifespan that was 10.66 days shorter than those in the control group after being exposed to −8 °C. Furthermore, the average number of eggs laid by females at −8 °C was 4.46 less than that at 8 °C and 6.16 less than that in the control group, which laid an average of 21.55 eggs. The net reproductive rate (R0) of T. drosophilae decreased with lower temperatures, reaching a low of 23.64 at −8 °C. Conversely, the intrinsic growth rate (rm) actually increased as temperatures dropped, with the lowest value being 0.21 at −8 °C.ConclusionsThe findings indicate that short-term exposure to low temperatures hampers the growth and population increase of T. drosophilae, thereby reducing their effectiveness as biological control agents.Graphical

Temperature Dependence and the Effects of Ultraviolet Radiation on the Ultrastructure and Photosynthetic Activity of Carpospores in Sub-Antarctic Red Alga Iridaea cordata (Turner) Bory 1826.

The short-term effects of UV radiation and low temperature on ultrastructure, photosynthetic activity (measured as the maximal photochemical quantum yield of photosystem II: Fv/Fm), chlorophyll-a (Chl-a) contents, and UV-absorbing compounds on the carpospores of Iridaea cordata from a sub-Antarctic population were investigated. Exposure to both photosynthetically active radiation (PAR) and PAR + UV for 4 h caused ultrastructural modifications in all treatments. Under PAR + UV at 2 °C, a disruption of the chloroplast's internal organization was observed. Plastoglobuli were often found in carpospores exposed to 2 °C. 'Electron dense particles', resembling physodes of brown algae, were detected for the first time in cells exposed to PAR and PAR + UV at 8 °C. Fv/Fm decreased following 4 h exposure at 2 °C under PAR + UV (64%) and PAR (25%). At 8 °C, Fv/Fm declined by 21% only under PAR + UV. The photosynthesis of carpospores previously treated with UV partially recovered after a 4 h exposure under dim light. UV-absorbing compounds were degraded in all radiation and temperature treatments without recovery after a 4 h dim light period. Chl-a did not change, whereas total carotenoids increased under PAR at 8 °C The study indicates that although carpospores of I. cordata exhibit photoprotective mechanisms, UV radiation strongly damages their ultrastructure and physiology, which were exacerbated under low temperatures.

Short-Term Effects of Lower Air Temperature and Cold Spells on Myocardial Infarction Hospitalizations in Sweden

BackgroundLower air temperature and cold spells have been associated with an increased risk of various diseases. However, the short-term effect of lower air temperature and cold spells on myocardial infarction (MI) remains incompletely understood. ObjectivesThe purpose of this study was to investigate the short-term effects of lower air temperature and cold spells on the risk of hospitalization for MI in Sweden. MethodsThis population-based nationwide study included 120,380 MI cases admitted to hospitals in Sweden during the cold season (October to March) from 2005 to 2019. Daily mean air temperature (1 km2 resolution) was estimated using machine learning, and percentiles of daily temperatures experienced by individuals in the same municipality were used as individual exposure indicators to account for potential geographic adaptation. Cold spells were defined as periods of at least 2 consecutive days with a daily mean temperature below the 10th percentile of the temperature distribution for each municipality. A time-stratified case-crossover design incorporating conditional logistic regression models with distributed lag nonlinear models using lag 0 to 1 (immediate) and 2 to 6 days (delayed) was used to evaluate the short-term effects of lower air temperature and cold spells on total MI, non–ST-segment elevation myocardial infarction (NSTEMI) and ST-segment elevation myocardial infarction (STEMI). ResultsA decrease of 1-U in percentile temperature at a lag of 2 to 6 days was significantly associated with increased risks of total MI, NSTEMI, and STEMI, with ORs of 1.099 (95% CI: 1.057-1.142), 1.110 (95% CI: 1.060-1.164), and 1.076 (95% CI: 1.004-1.153), respectively. Additionally, cold spells at a lag of 2 to 6 days were significantly associated with increased risks for total MI, NSTEMI, and STEMI, with ORs of 1.077 (95% CI: 1.037-1.120), 1.069 (95% CI: 1.020-1.119), and 1.095 (95% CI: 1.023-1.172), respectively. Conversely, lower air temperature and cold spells at a lag of 0 to 1 days were associated with decreased risks for MI. ConclusionsThis nationwide case-crossover study reveals that short-term exposures to lower air temperature and cold spells are associated with an increased risk of hospitalization for MI at lag 2 to 6 days.

Short-term Effects of Ambient Temperature on Pediatric Incident Seizure: A Case-crossover Analysis Using Distributed Lag Non-linear Models

Short-term Effects of Ambient Temperature on Pediatric Incident Seizure: A Case-crossover Analysis Using Distributed Lag Non-linear Models

Resilience mechanisms of Trichopria drosophilae (Hymenoptera: Diapriinae) under global extreme cooling: insights into parasitic response and physiological adaptation.

Global climate warming and frequent extreme low-temperature events have made it essential to investigate the impact of low temperatures on parasitic wasps to protect and strengthen farmland biodiversity, which in turn enhances the biological control potential of natural enemies such as parasitic wasps. We systematically examined how low-temperature stress affects the parasitic functional response of Trichopria drosophilae to Drosophila suzukii (Diptera: Drosophilidae) pupae. Our findings indicate that the parasitic behavior of T. drosophilae towards D. suzukii pupae aligns with the Holling II functional response model following exposure to different temperatures. Within the temperature range of 8 °C to -8 °C, lower temperatures correlated decreased instantaneous attack rate of T. drosophilae and an increase in processing time. The search constant Q initially increased and then decreased with declining temperatures. Short-term low-temperature stress negatively impacted the parasitic and searching abilities of T. drosophilae but did not alter its parasitic functional response model. Notably, short-term low-temperature stress had minimal effects on the water content, protein content, and total sugar content of male and female T. drosophilae adults. However, as temperatures decreased, the activities of key enzymes, including GAPDH, SOD, T-AOC, and malondialdehyde (MDA), exhibited an initial increase followed by a decrease. Conversely, the activities of LDH and HOAD decreased, while the activities of CAT and POD increased. Further study on the effect of short-term low temperature on T. drosophilae can provide a research basis for the large-scale production and low-temperature refrigeration technology of T. drosophilae, and provide a scientific basis for its efficient use in the field.

Different climate conditions drive variations in gross primary productivity and woody biomass accumulation in a temperate and a boreal conifer forest in Canada

Understanding the complex relationships between climate, forest carbon (C) uptake and biomass growth has become a research priority, crucial for assessing the climate change impacts on forest C sequestration. Such associations are expected to vary across biomes, due to different climate constraints on tree physiology. However, our understanding of the seasonal dynamics of long-term C sequestration and how climate influences them in different forest biomes is still limited.We investigated a boreal Pinus banksiana forest (Old Jack Pine, OJP) and a temperate Pinus strobus plantation (Turkey Point, TP39) in Canada. We aimed to assess the link between C uptake and above-ground woody biomass growth, and the effects of climate inter-annual variability on them. We used daily records of climate and gross primary productivity (GPP, period 1999–2019 at OJP and 2003–2018 at TP39), and investigated xylem biomass proxies at cell (cell wall area) and tree-ring level (ring wall area) from 1970 to 2019 at OJP, and from 1970 to 2018 at TP39.In both forests, the direct link between C sink and C source was revealed by the common inter-annual variability of GPP and xylem biomass. GPP and xylem biomass were mostly influenced by spring and late summer temperature at OJP. However, at both sites, summer drought negatively influenced GPP, and biomass growth especially in recent decades. Analysis of dry and cold years evidenced short-term negative effects of low temperature on GPP and xylem biomass in OJP, and of drought in TP39.Long-term intra-annual analyses are crucial to assess the variable effects of climate on forest C cycle. Warm spring and autumn can benefit both GPP and biomass growth, but even in the boreal forest, summer drought has negative impacts. Increasing dry spells, especially in the temperate site, could reduce future forest capacity to uptake C and fix it in wood biomass.

The short-term effect of apparent temperature on the hydration marker plasma sodium

The short-term effect of apparent temperature on the hydration marker plasma sodium

A nationwide time-series analysis for short-term effects of ambient temperature on violent crime in South Korea

Psychological theories on heat-aggression relationship have existed for decades and recent models suggest climate change will increase violence through varying pathways. Although observational studies have examined the impact of temperature on violent crime, the evidence for associations is primarily limited to coarse temporal resolution of weather and crime (e.g., yearly/monthly) and results from a few Western communities, warranting studies based on higher temporal resolution data of modern systemic crime statistics for various regions. This observational study examined short-term temperature impacts on violent crime using national crime data for the warm months (Jun.–Sep.) across South Korea (2016–2020). Distributed lag non-linear models assessed relative risks (RRs) of daily violent crime counts at the 70th, 90th, and 99th summer temperature percentiles compared to the reference temperature (10th percentile), with adjustments for long-term trends, seasonality, weather, and air pollution. Results indicate potentially non-linear relationships between daily summer temperature (lag0–lag10) and violent crime counts. Violent crimes consistently increased from the lowest temperature and showed the highest risk at the 70th temperature (~ 28.0 °C). The RR at the 70th and 90th percentiles of daily mean temperature (lag0–lag10), compared to the reference, was 1.11 (95% CI 1.09, 1.15) and 1.04 (95% CI 1.01, 1.07), indicating significant associations. Stratified analysis showed significant increases in assault and domestic violence for increases in temperature. The lagged effects, the influences of heat on subsequent crime incidence, did not persist 21 days after the exposure, possibly due to the displacement phenomenon. We found curvilinear exposure–response relationships, which provide empirical evidence to support the psychological theories for heat and violence. Lower public safety through increased violent crime may be an additional public health harm of climate change.

Light intensity influences the glycerolipid remodeling of Gracilariopsis lemaneiformis in response to short-term high temperature stress

Temperature and light are two pivotal environmental factors for the growth of marine photosynthetic organisms. While the responses of Gracilariopsis lemaneiformis to individual high temperature or light stress have been explored, our understanding of its combined stress responses remains limited. This study aimed to investigate the combined effects of short-term high temperature (33 °C, 8 h) and different light intensities, that is, low light (LL, 50 μmol photon m−2 s−1), medium light (ML, 150 μmol photon m−2 s−1), and high light (HL, 300 μmol photon m−2 s−1), on the physiological responses and lipid remodeling of G. lemaneiformis. Results demonstrated that short-term exposure to either high temperature or high light stress led to a reduction in maximum (Fv/Fm), effective photochemical efficiency (Fv'/Fm') and maximum relative electron transfer rate (rETRmax), and the combination of these stresses exerted a more pronounced inhibitory effect on photosystem II efficiency. Short-term exposure to heat stress led to an increase in superoxide dismutase (SOD) activity, as well as a rise in glutathione (GSH) and ascorbate (Asc) contents under LL, while the activities of antioxidant enzymes (SOD, peroxidase, and ascorbate peroxidase) and levels of non-enzymatic antioxidants (GSH and Asc) were reduced under ML and HL. Additionally, short-term heat stress induced the accumulations of phosphatidylcholine (PC), phosphatidylethanolamine, phosphatidylserine, phosphatidylglycerol, sulfoquinovosyldiacylglycerol, and triacylglycerol (TAG) under LL, while heat-induced lipid accumulation decreased under ML and HL. Furthermore, heat stress increased the accumulation of saturated or unsaturated PC species under LL. Specifically, there was an increase in the levels of saturated or monounsaturated acyl chain–containing PC species, whereas the levels of polyunsaturated acyl chain-containing PC species declined under ML and HL. Correspondingly, a significant increase in TAG species with polyunsaturated acyl chains was observed, particularly under LL conditions, suggesting a potential lipid turnover between PC and TAG. These results showed that the lipid metabolic plasticity of G. lemaneiformis enabled it to rapidly adapt to fluctuating environmental conditions, and the light environment regulated its heat stress response.

Short-Term Effect of Ambient Temperature in Acute Ischemic Stroke with Endovascular Treatment Due to Large Vessel Occlusion.

Acute ischemic stroke (AIS) stands as the primary cause of mortality and extended disability globally. While prior studies have examined the connection between stroke and local weather, they have produced conflicting results. Our goal was to examine the correlation between temperature and functional prognosis in patients with large vessel occlusion (LVO) undergoing endovascular therapy (EVT). This study included a total of 1809 patients. Temperatures from stroke onset to groin puncture were categorized into Cold (10th percentile of temperature), Cool (10th-50th percentile of temperature), Warm (50th-90th percentile of temperature), and Hot (90th percentile of temperature) groups. The primary efficacy result was the modified Rankin Scale (mRS) score at 90 days. Safety outcomes included mortality, symptomatic intracranial hemorrhage (sICH) and complications after cerebral infarction. The primary efficacy results demonstrated a statistical enhancement in functional outcomes at 90 days for patients in the Warm group compared to the Cold group (adjusted common odds ratio [OR]: 1.386; 95% confidence interval [CI]: 1.024-1.878, P=0.035). Secondary efficacy results showed that temperature was associated with a higher rate of 90-day functional independence (adjusted OR: 1.016; 95% CI: 1.004-1.029; P=0.009), which was higher in the Warm group compared with patients in the Cold group (adjusted OR: 1.646; 95% CI: 1.107-2.448, P=0.014). There were no significant differences between groups in terms of sICH, 90-day mortality, and post-infarction complications. Compared with Cold temperature, Warm temperature is associated with better functional outcomes and reduced mortality risk without increasing the risk of sICH.

Short-term effects of ambient temperature on acute exacerbation of inflammatory bowel disease: A nationwide case-crossover study with external validation.

Inflammatory bowel disease (IBD) is an idiopathic inflammatory disorder characterized by chronic and relapsing manifestations. Several environmental factors are known as triggers for exacerbation of IBD. However, an association between exacerbation of IBD and ambient temperature is uncertain. This study aimed to estimate the risk of acute exacerbation of IBD due to ambient temperature. We performed a bidirectional case-crossover study using a nationwide claim data from South Korea. The external validation was conducted with a large prospective cohort in the United Kingdom. We confirmed significant associations between acute exacerbation of IBD and the short-term ambient temperature changes toward severe temperatures, in the cold weather (-19.4°C-4.3°C) (odd ratio [OR] = 1.13, 95% confidence interval [CI]: 1.13-1.14) and in the hot weather (21.3°C-33.5°C) (OR = 1.16, 95% CI: 1.15-1.17). However, the association was not significant in the moderate weather (4.3°C-21.3°C). The external validation suggested consistent results with additional elevation of acute exacerbation risk in the colder weather (-13.4°C to 2.6°C) (OR = 1.90, 95% CI: 1.62-2.22) and in the hotter weather (15.7°C-28.4°C) (OR = 1.41, 95% CI: 1.32-1.51). We observed and validated that the short-term ambient temperature changes were associated with acute exacerbation of IBD in the cold and hot weathers. Our findings provide evidence that temperature changes are associated with the acute exacerbation of IBD.

Effect of Short-Term Storage Temperature on Mechanical Properties of ‘Istanbul’ Medlar

The study investigated the effect of short-term storage time on the mechanical (rupture force, rupture energy, deformation) properties of the ‘Istanbul’ medlar cultivar grafted on Quince A (QA) and Quince Province BA29 (BA29) quince clone rootstock. The study gives the average values of the physical properties (weight, size, geometric mean diameter, sphericity, surface area, true density, bulk density, and porosity) of the ‘Istanbul’ medlar cultivar. The changes in breaking force, breaking energy, and deformation values of 'Istanbul' medlar varieties stored at room temperature (251 °C) and cold storage (41 °C) for 5 days were investigated. Separate measurements were made for skin and skinless fruits. The average rupture force value of fruits of the ‘Istanbul’ medlar cultivar stored at 25 °C was determined as 8.82 N, deformation 4.66 mm, and rupture energy 0.035 J. The average rupture force value of the fruits of the ‘Istanbul’ medlar cultivar stored at 4 °C was determined as 10.06 N, deformation 5.16 mm, and rupture energy 0.043 J. It was found that the storage conditions had a statistically significant effect on the rupture force, rupture energy, and deformation values of the QA and BA29 rootstocks of the ‘Istanbul’ medlar cultivar (P≤0.001).

Short-term effects of air pollution and weather changes on the occurrence of acute aortic dissection in a cold region.

Air pollution and severe weather conditions can adversely affect cardiovascular disease emergencies. Nevertheless, it remains unclear whether air pollutants and low ambient temperature can trigger the occurrence of acute aortic dissection (AAD) in cold regions. We applied a retrospective analysis to assess the short-term effects of air pollution and ambient temperature on the occurrence of AAD in Harbin, China. A total of 564 AAD patients were enrolled from a major hospital in Harbin between January 1, 2017, and February 5, 2021. Weather condition data and air pollutant concentrations, including fine particulate matter smaller than 10 μm (PM10) and 2.5 μm in diameter (PM2.5), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), and ozone (O3), were collected every day. Conditional logistic regressions and correlation analysis were applied to analyze the relationship of environmental and atmospheric parameters with AAD occurrence at lags of 0 to 7 days. Specifically, we appraised the air quality index, CO, NO2, SO2, O3, PM10, PM2.5, temperature, dew point temperature, atmospheric pressure, and cloud amount. A total of 1,496 days at risk were assessed, of which 564 patients developed AAD. Specifically, AAD did not occur on 1,043 (69.72%) days, while 1 or more cases occurred on 453 (30.28%) days. Several pollution and weather predictors for AAD were confirmed by multilevel modeling. The air quality index (p = 0.0012), cloud amount (p = 0.0001), and concentrations of PM2.5 (p = 0.0004), PM10 (p = 0.0013), NO2 (p = 0.0007) and O3 (p = 0.0001) predicted AAD as early as 7 days before the incident (lag of 7 days) in the study period. However, only concentrations of the air pollutants NO2 (p = 0.0468) and O3 (p = 0.011) predicted the occurrence of AAD after the COVID-19 outbreak. Similar predictive effects were observed for temperature, dew point temperature, and atmospheric pressure (all p < 0.05) on all days. The risk of AAD is closely related to air pollution and weather characteristics in Harbin. While causation was not determined, the impact of air pollutants on the risk of AAD was reduced after the COVID-19 outbreak.

Effect of thermal ageing on electrical, mechanical properties of glass fiber reinforced polymer and its impact on service life

The mechanical and electrical properties of polymer composites often degrade due to environmental factors and shorten their service life. This article presents the effect of high temperatures on the mechanical and electrical characteristics of glass fiber reinforced composites and from the measurements, an attempt is made to predict the service life. Electrical conductivity, impedance and resistance are studied with a short-term temperature effect at 30, 60, 120, and 180 °C. The effect of temperature exposure at 120 and 160 °C for 1000, 2000, and 3000 h has been investigated to assess the changes in flexural, compressive, and tensile properties and for prediction of service life. Morphological studies are carried out to support some of the experimental results. The mechanical properties of composites are observed to deteriorate with the duration of aging. Flexural, tensile, and compressive strengths reveal a reduction of 8, 10, and 9%, after aging at 3000 h at 160 °C. The tensile strength and tensile modulus at 120 °C aged for 3000 h exhibit minimal changes as compared to unaged composites. However, with an increase in temperature to 160 °C, there is a reduction in tensile strength and modulus of composites by less than 10%, and 6% compared to composites with nanofillers. The variations in compression strength at 120 and 160 °C is not significant. Based on the reduction of tensile strength with temperature, the service life of composites has been estimated. For a predicted service life of 20 years, composites with nanofillers would be able to retain tensile strength of 90% of tensile strength.

Digestive enzyme activity and macromolecule content in the hemolymph of differentially adapted Lymantria dispar L. populations after short-term increases in ambient temperature

Global, unpredictable temperature increases have strong effects on all organisms, especially insects. Elucidating the effects of short-term temperature increases on midgut digestive enzymes (α-glucosidase, lipase, trypsin, and leucine aminopeptidase - LAP) and metabolic macromolecules in the hemolymph (proteins, lipids, and trehalose) of phytophagous pest larvae of Lymantria dispar is important for general considerations of insect adaptation to a warming climate and potential pest control options. We also wanted to determine whether the different adaptations of L. dispar populations to environmental pollution might affect their ability to cope with heat stress using larvae from the undisturbed, Kosmaj forest and disturbed, Lipovica forest. Heat treatments at 28 °C increased α-glucosidase activity in both larval populations, inhibited LAP activity in larvae from the polluted forest, and had no significant effect on trypsin and lipase activities, regardless of larval origin. The concentration of proteins, lipids, and trehalose in the hemolymph of larvae from the disturbed forest increased, whereas the population from the undisturbed forest showed only an increase in proteins and lipids after the heat treatments. Larval mass was also increased in larvae from the undisturbed forest. Our results suggest a higher sensitivity of digestive enzymes and metabolism to short-term heat stress in L. dispar populations adapted to pollution in their forest habitat, although climate warming is not beneficial even for populations from unpolluted forests. The digestive and metabolic processes of L. dispar larvae are substantially affected by sublethal short-term increases in ambient temperature.

Physiological Basis of High Nighttime Temperature-Induced Chalkiness Formation during Early Grain-Filling Stage in Rice (Oryza sativa L.)

Heat stress during the grain-filling stage seriously affects grain quality in rice. However, very limited information is available regarding the effects of short-term high nighttime temperature (HNT) on grain chalkiness formation in rice. In this paper, the effects of HNT at the early grain-filling stage (7 days after ear emergence) on rice chalkiness formation and the potential causes were investigated by using two rice varieties that differed in susceptibility to high temperature. Although the HNT treatment at night dramatically increased the grain chalkiness in Jiuxiangzhan (JXZ) and Huanghuazhan (HHZ), the increase was greater in JXZ compared to HHZ. The net photosynthetic rate and SPAD value were significantly reduced by HNT treatment in the flag leaves of JXZ, while no significant differences were observed in HHZ. Furthermore, HNT treatment reduced the antioxidant enzyme activity in the flag leaves of JXZ, while the opposite was observed in HHZ, exhibiting increased antioxidant enzyme activity. Moreover, HNT treatment altered the endogenous hormone levels, enhanced the enzymatic activities related to starch biosynthesis, and accelerated the filling rate in grains of JXZ when compared to HHZ. Scanning electron microscopy (SEM) observation exhibited that the starch granules in the endosperm of JXZ were loosely packed together and more starch granules with small pits were produced after HNT treatment. Based on these data, we inferred that HNT stress during the early stage of rice grain filling accelerated the grain-filling rate but shortened the grain-filling duration by changing the endogenous hormone levels and enhancing the enzymatic activities responsible for starch biosynthesis, resulting in significant changes in the morphological structure and arrangement of starch granules and eventually causing the occurrence of grain chalkiness.

Evaluating the short-term effect of ambient temperature on non-fatal outdoor falls and road traffic injuries among children and adolescents in China: a time-stratified case-crossover study.

Supplementary material is available in the online version of this article at 10.1007/s11783-023-1705-1 and is accessible for authorized users.

Short-term effect of apparent temperature on daily hospitalizations for osteoporotic fractures in Beijing, China: A retrospective observational study

BackgroundStudies on the associations between temperature and osteoporotic fractures (OF) hospitalizations are limited. This study aimed to assess the short-term effect of apparent temperature (AT) on the risk of OF hospitalizations. MethodsThis retrospective observational study was conducted in Beijing Jishuitan Hospital from 2004 to 2021. Daily OF hospitalizations, meteorological variables and fine particulate matter were collected. A Poisson generalized linear regression model combined with a distributed lag non-linear model was applied to analyze the lag-exposure-response relationship between AT and the number of OF hospitalizations. Subgroup analysis by gender, age and fracture type was also conducted. ResultsTotal daily hospitalization visits for OF during the studied period were 35,595. The exposure-response curve of AT and OF presented a non-linear relationship, with optimum apparent temperature (OAT) at 28.40 °C. Taking OAT as the reference, the cold effect (−10.58 °C, 2.5th percentage) on single lag day had statistical significance from the current day of exposure (RR = 1.18, 95 % CI: 1.08–1.28) to lag 4 day (RR = 1.04, 95 % CI: 1.01–1.08), while the cumulative cold effect increased the risk of OF hospitalization visits from lag 0 to 14 days, with the maximum RR over lag 0–14 days (RR = 1.84, 95 % CI: 1.21–2.79). There were no significant risks of OF hospitalizations for warm effects (32.53 °C, 97.5th percentage) on single or cumulative lag days. The cold effect might be more evident among females, patients aged 80 years or older, and patients with hip fractures. ConclusionExposure to cold temperatures is associated with an increased risk of OF hospitalizations. Females, patients aged 80 years or older and patients with hip fractures might be more vulnerable to the cold effect of AT.

Short-term exposure to temperature and mental health in North Carolina: a distributed lag nonlinear analysis.

Adverse mental health outcomes have been associated with high temperatures in studies worldwide. Few studies explore a broad range of mental health outcomes, and to our knowledge, none are specific to NC, USA. This ecological study explored the relationship between ambient temperature and mental health outcomes (suicide, self-harm and suicide ideation, anxiety and stress, mood disorders, and depression) in six urban counties across the state of NC, USA. We applied a quasi-Poisson generalized linear model combined with a distributed lag nonlinear model (DLNM) to examine the short-term effects of daily ambient temperature on emergency admissions for mental health conditions (2016 to 2018) and violent deaths (2004 to 2018). The results were predominately insignificant, with some key exceptions. The county with the greatest temperature range (Wake) displays higher levels of significance, while counties with the lowest temperature ranges (New Hanover and Pitt) are almost entirely insignificant. Self-harm and suicidal ideation peak in the warm months (July) and generally exhibit a protective effect at lower temperatures and shorter lag intervals. Whereas anxiety, depression, and major depressive disorders peak in the cooler months (May and September). Suicide is the only outcome that favored a 20-day lag period in the sensitivity analysis, although the association with temperature was insignificant. Our findings suggest additional research is needed across a suite of mental health outcomes to fully understand the effects of temperatures on mental health.