Dealing with hot rocky environments: Critical thermal maxima and locomotor performance in Leptodactylus lithonaetes (Anura: Leptodactylidae)

2019 ◽  
pp. 155-161 ◽  
Author(s):  
Ivan Beltran
Keyword(s):  
Environmental Temperature ◽  
Extreme Temperature ◽  
Effect Of Temperature ◽  
Maximum Speed ◽  
Locomotor Performance ◽  
Extreme Temperatures ◽  
Physiological Limits ◽  
Fitness Consequences ◽  
Thermal Maximum ◽  
Environmental Temperatures

Environmental temperature has fitness consequences on ectotherm development, ecology and behaviour. Amphibians are especially vulnerable because thermoregulation often trades with appropriate water balance. Although substantial research has evaluated the effect of temperature in amphibian locomotion and physiological limits, there is little information about amphibians living under extreme temperature conditions. Leptodactylus lithonaetes is a frog allegedly specialised to forage and breed on dark granitic outcrops and associated puddles, which reach environmental temperatures well above 40 ˚C. Adults can select thermally favourable microhabitats during the day while tadpoles are constrained to rock puddles and associated temperature fluctuations; we thus established microhabitat temperatures and tested whether the critical thermal maximum (CTmax) of L. lithonaetes is higher in tadpoles compared to adults. In addition, we evaluated the effect of water temperature on locomotor performance of tadpoles. Contrary to our expectations, puddle temperatures were comparable and even lower than those temperatures measured in the microhabitats used by adults in the daytime. Nonetheless, the CTmax was 42.3 ˚C for tadpoles and 39.7 ˚C for adults. Regarding locomotor performance, maximum speed and maximum distance travelled by tadpoles peaked around 34 ˚C, approximately 1 ˚C below the maximum puddle temperatures registered in the puddles. In conclusion, L. lithonaetes tadpoles have a higher CTmax compared to adults, suggesting a longer exposure to extreme temperatures that lead to maintain their physiological performance at high temperatures. We suggest that these conditions are adaptations to face the strong selection forces driven by this granitic habitat.

Effect of temperature on erythropoiesis and red cell survival in the frog

1962 ◽  
Vol 203 (3) ◽  
pp. 401-403 ◽  
Author(s):  
M. J. Cline ◽  
T. A. Waldmann
Keyword(s):  
Life Span ◽  
Cell Survival ◽  
Cell Volume ◽  
Environmental Temperature ◽  
Red Cells ◽  
Effect Of Temperature ◽  
Red Cell ◽  
Cell Life ◽  
Red Cell Survival ◽  
Environmental Temperatures

The effect of environmental temperature on erythropoiesis and erythrocyte life span was studied in frogs maintained at 4 C or 24–26 C. The red cell incorporation of radioiron was used as an index of the rate of erythropoiesis and diisopropylfluorophosphate-P32 was used to measure red cell survival. The red cell life span in frogs kept at 24–26 C was approximately 200 days. The incorporation of Fe59 into circulating red cells during the first 10 days after isotope administration was significantly greater in frogs at 24–26 C than in frogs at 4 C. The peripheral hematocrit decreased in groups of frogs kept at 4 C during the period of observation. The inconstancy of the hematocrit and presumably of the total red cell volume did not permit any definite conclusions regarding the apparently longer erythrocyte life span at low environmental temperatures.

scholarly journals Termites have developed wider thermal limits to cope with environmental conditions in savannas

2021 ◽  
Author(s):  
Joel Shutt Woon ◽  
David Atkinson ◽  
Stephen Adu-Bredu ◽  
Paul Eggleton ◽  
Catherine L. Parr
Keyword(s):  
Tropical Forests ◽  
Environmental Conditions ◽  
Thermal Tolerance ◽  
Canopy Cover ◽  
Daily Rainfall ◽  
Extreme Temperatures ◽  
Termite Species ◽  
Thermal Limits ◽  
Physiological Limits ◽  
Thermal Maximum

The most diverse and abundant family of termites, the Termitidae, evolved in warm, wet African tropical forests. Since then, they have colonised grassy biomes such as savannas. These environments have more extreme temperatures than tropical forests, and greater temporal fluctuations (both annually and diurnally) that are challenging for soft-bodied ectotherms. We propose that that a likely mechanism that facilitated the expansion from forest to savanna was the widening of physiological limits of savanna termite species in order to cope with more extreme environmental conditions. We sampled termites directly from mound structures across an environmental gradient in Ghana, and recorded the thermal tolerance of individual termites, both critical thermal maximum (CTmax) and critical thermal minimum (CTmin). We estimated colony thermal tolerance by taking an average of each tested individual, and modelled these data against several environmental factors (canopy cover above the mound, rainfall and temperature). We found that savanna termite species had significantly higher CTmax values, and significantly lower CTmin values, than forest species. In addition, areas with high canopy cover were significantly associated with low CTmax values, and areas with higher average daily rainfall were significantly associated with higher CTmin values. Our results suggest that the widening of thermal tolerances has occurred in savanna termite species, probably in response to the more extreme temperatures found in those environments.

Thermal acclimation of locomotor performance in anuran amphibians

1986 ◽  
Vol 64 (9) ◽  
pp. 1956-1960 ◽  
Author(s):  
Kirk Miller ◽  
Gregory M. Zoghby
Keyword(s):  
Xenopus Laevis ◽  
Environmental Temperature ◽  
Thermal Acclimation ◽  
Bufo Marinus ◽  
Effect Of Temperature ◽  
Locomotor Performance ◽  
Temperature Changes ◽  
Leopard Frogs ◽  
Anuran Species ◽  
Improved Performance

Acclimation is the principal strategy employed by amphibians in coping with environmental temperature changes, yet acclimation has only rarely been shown to affect aspects of whole-organism function in amphibians. We examined the influence of a period of acclimation on the effect of temperature on locomotion in three anuran species. Giant toads, Bufo marinus, moved most quickly at 22 °C, and acclimation to that temperature further improved performance (inverse compensation). Leopard frogs, Ranapipiens, also moved most quickly at 22 °C, but acclimation to 12 °C improved locomotor performance at that temperature (positive compensation). Clawed frogs, Xenopus laevis, in contrast, moved most quickly at 12 °C and acclimation did not affect locomotor performance in this species (no compensation). Thus, while acclimation clearly affects locomotor performance in some anuran species, the direction of change differs among them.

The effects of environmental temperature and method of feeding on the performance and carcass composition of bacon pigs

1967 ◽  
Vol 9 (2) ◽  
pp. 209-218 ◽  
Author(s):  
D. W. Holme ◽  
W. E. Coey
Keyword(s):  
Environmental Temperature ◽  
Average Daily Gain ◽  
Carcass Composition ◽  
Restricted Feeding ◽  
Feed Conversion ◽  
Feeding Method ◽  
Feeding Regimes ◽  
Higher Temperature ◽  
Ad Libitum ◽  
Environmental Temperatures

A trial designed to investigate the effects of two environmental temperatures, three feeding regimes and the interactions between them is described. A temperature of 72° F. was better than one of 54° F. for bacon pigs between 40 lb. and 200 lb. weight. The higher temperature resulted in faster growth, more efficient feed conversion and increased length of carcass. Other carcass characteristics were not significantly altered. Ad libitum feeding resulted in faster growth and fatter carcasses than restricted feeding, but did not have a significant effect on efficiency of feed conversion. When feed intake was restricted, feeding pigs once daily or twice daily resulted in similar performance and carcass composition.There was a significant interaction between environmental temperature and feeding method for average daily gain in that pigs fed ad libitum grew faster at the low temperature and pigs fed restricted amounts of feed grew faster at the high temperature. No other interaction reached significant levels.

Temporal trends of the association between extreme temperatures and hospitalisations for schizophrenia in Hefei, China from 2005 to 2014

2021 ◽  
Vol 78 (5) ◽  
pp. 364-370
Author(s):  
Rubing Pan ◽  
Qizhi Wang ◽  
Weizhuo Yi ◽  
Qiannan Wei ◽  
Jian Cheng ◽  
...  
Keyword(s):  
Time Series Data ◽  
Temporal Trends ◽  
Extreme Temperature ◽  
Series Data ◽  
Extreme Temperatures ◽  
Distributed Lag ◽  
Increasing Trend ◽  
Related Hospitalisation ◽  
Extreme Cold ◽  
And Gender

ObjectiveWe aimed to examine the temporal trends of the association between extreme temperature and schizophrenia (SCZ) hospitalisations in Hefei, China.MethodsWe collected time-series data on SCZ hospitalisations for 10 years (2005–2014), with a total of 36 607 cases registered. We used quasi-Poisson regression and distributed lag non-linear model (DLNM) to assess the association between extreme temperature (cold and heat) and SCZ hospitalisations. A time-varying DLNM was then used to explore the temporal trends of the association between extreme temperature and SCZ hospitalisations in different periods. Subgroup analyses were conducted by age (0–39 and 40+ years) and gender, respectively.ResultsWe found that extreme cold and heat significantly increased the risk of SCZ hospitalisations (cold: 1st percentile of temperature 1.19 (95% CI 1.04 to 1.37) and 2.5th percentile of temperature 1.16 (95% CI 1.03 to 1.31); heat: 97.5th percentile of temperature 1.37 (95% CI 1.13 to 1.66) and 99th percentile of temperature 1.38 (95% CI 1.13 to 1.69)). We found a slightly decreasing trend in heat-related SCZ hospitalisations and a sharp increasing trend in cold effects from 2005 to 2014. However, the risk of heat-related hospitalisation has been rising since 2008. Stratified analyses showed that age and gender had different modification effects on temporal trends.ConclusionsThe findings highlight that as temperatures rise the body’s adaptability to high temperatures may be accompanied by more threats from extreme cold. The burden of cold-related SCZ hospitalisations may increase in the future.

Influence of the environmental temperature on the post-partum testosterone surge in the rat

1987 ◽  
Vol 115 (4) ◽  
pp. 478-482 ◽  
Author(s):  
J. Roffi ◽  
F. Chami ◽  
P. Corbier ◽  
D. A. Edwards
Keyword(s):  
Ambient Temperature ◽  
Environmental Temperature ◽  
Post Partum ◽  
Serum Testosterone ◽  
The Body ◽  
Male Rats ◽  
Effect Of Temperature ◽  
Male Rat ◽  
Foster Mother ◽  
The Central Nervous System

Abstract. In the neonatal male rat, a rapid and transient increase in serum testosterone occurs about 2 h after birth. This post-partum testosterone surge (PPTS) has been implicated in the masculinization and defeminization of the central nervous system. The present study shows that environmental temperature can have a profound influence on the PPTS. Male rats were delivered from their mothers by caesarean section on day 22 of gestation. Immediately thereafter, neonatal males were placed at an ambient temperature of either 18, 21, 24 or 30°C. With 2 h of exposure, the body temperature was in close correspondence with the ambient temperature. The PPTS was clearly abolished in the pups exposed for 2 h at either 18 or 21°C. The effect of temperature was reversible: by placing pups at either 18 or 21°C for 2 h after delivery, and then rewarming by placing them with a foster mother, the PPTS was delayed until 4 h after birth, i.e. 2 h after the beginning of rewarming. Thus, environmental cooling appears to retard the development of neural and/or endocrine systems mediating the PPTS. Aberrant maternal care which would produce substantial cooling of the male pups would be expected to affect the PPTS, which in turn might affect the sexuality of male progeny.

scholarly journals Estimating changes of temperatures and precipitation extremes in India using the Generalized Extreme Value (GEV) distribution

2018 ◽  
Author(s):  
Kishore Pangaluru ◽  
Isabella Velicogna ◽  
Tyler C. Sutterley ◽  
Yara Mohajerani ◽  
Enrico Ciraci ◽  
...  
Keyword(s):  
Extreme Temperature ◽  
Extreme Value ◽  
Precipitation Extremes ◽  
Temperature Extremes ◽  
Extreme Temperatures ◽  
Return Periods ◽  
Generalized Extreme Value ◽  
Gev Distribution ◽  
Cold Extreme ◽  
Temperature And Precipitation

Abstract. Changes in extreme temperature and precipitation may give some of the largest significant societal and ecological impacts. For changes in the magnitude of extreme temperature and precipitation over India, we used a statistical model of generalized extreme value (GEV) distribution. The GEV statistical distribution is a time-dependent distribution with different time scales of variability bounded by a precipitation, maximum (Tmax), and minimum (Tmin) temperature extremes and also assessed their possibility changes are evaluated and quantified over India is presented. The GEV-based method is applied on both precipitation and temperature extremes over India during the 20th and 21st centuries using multiple coupled climate models taking an interest in the Coupled Model Intercomparison Project Phase 5 (CMIP5) and observational datasets. The regional means of historical warm extreme temperatures are 34.89, 36.42, and 38.14 °C for three different (10, 20, and 50-year) periods, respectively; whereas the cold extreme mean temperatures are 7.75, 4.19, and −1.57 °C. It indicates that 20th century cold extreme temperatures have relatively larger variations than the warm extremes. As for the future, the CMIP5 models of warm extreme regional mean values increase from 0.33 to 0.75 °C in all return periods (10-, 20-, and 50-year periods), while in the case of cold extreme means values vary between 0.58 and 2.29 °C. In the future, cold extreme values have a larger increasing rate over the northwest, northeast, some parts of north-central, and Inter Peninsula regions. The CRU precipitation extremes are larger than the historical extreme precipitation in all three (10, 20, and 50-year) return-periods.

scholarly journals Assessment of Seasonal Variability of Extreme Temperature in Mainland China under Climate Change

2021 ◽  
Vol 13 (22) ◽  
pp. 12462
Author(s):  
Wei-Xiong Yan ◽  
Jun-Fang Zhao ◽  
Jian-Ping Li ◽  
Yun-Xia Wang
Keyword(s):  
Annual Cycle ◽  
Seasonal Cycle ◽  
Mainland China ◽  
Extreme Temperature ◽  
Spatial Characteristic ◽  
Maximum Temperature ◽  
Positive Trend ◽  
Extreme Temperatures ◽  
Annual Average ◽  
Temperature Seasonality

Some studies have suggested that variations in the seasonal cycle of temperature and season onset could affect the efficiency in the use of radiation by plants, which would then affect yield. However, the study of the temporal variation in extreme climatic variables is not sufficient in China. Using seasonal trend analysis (STA), this article evaluates the distribution of extreme temperature seasonality trends in mainland China, describes the trends in the seasonal cycle, and detects changes in extreme temperature characterized by the number of hot days (HD) and frost days (FD), the frequency of warm days (TX90p), cold days (TX10p), warm nights (TN90p), and cold nights (TN10p). The results show a statistically significant positive trend in the annual average amplitudes of extreme temperatures. The amplitude and phase of the annual cycle experience less variation than that of the annual average amplitude for extreme temperatures. The phase of the annual cycle in maximum temperature mainly shows a significant negative trend, accounting for approximately 30% of the total area of China, which is distributed across the regions except for northeast and southwest. The amplitude of the annual cycle indicates that the minimum temperature underwent slightly greater variation than the maximum temperature, and its distribution has a spatial characteristic that is almost bounded by the 400 mm isohyet, increasing in the northwest and decreasing in the southeast. In terms of the extreme air temperature indices, HD, TX90p, and TN90p show an increasing trend, FD, TX10p, and TN10p show a decreasing trend. They are statistically significant (p < 0.05). This number of days also suggests that temperature has increased over mainland China in the past 42 years.

​Impact of Extreme Hot Environmental Temperature Period on Marker Enzymes of Carbohydrate Metabolism in Non-descript Sheep from Arid Tracts of Rajasthan

2021 ◽  
Author(s):  
Anandita Srivastava ◽  
Nalini Kataria
Keyword(s):  
Carbohydrate Metabolism ◽  
Environmental Temperature ◽  
Age Groups ◽  
Extreme Temperature ◽  
Mean Value ◽  
Marker Enzymes ◽  
Mean Values ◽  
The Mean ◽  
The Impact ◽  
Enzymes Of Carbohydrate Metabolism

Background: The present investigation was envisaged to find out the impact of extreme hot environmental temperature period (ETP) on marker enzymes of carbohydrate metabolism in male and female non-descript sheep of various age groups i.e. 4 to 13 months from arid tracts of Rajasthan. Glucose-6-phosphate dehydrogenase (G-6-PDH) and malate dehydrogenase (MDH) marker enzymes of carbohydrate metabolism were considered for study. Methods: During the period October 2016-June 2017 blood samples were collected to harvest sera for spectrophotometric method from 240 healthy animals selected from private slaughter house during moderate and extreme hot environmental temperature periods (ETPs). The mean values of markers attained during moderate ETP were reckoned as the control. It was 10.00 ± 0.10 UL-1 and 42.00±1.00 respectively. Conclusion: The mean value of MDH was significantly (p≤0.05) higher while G-6-PDH significantly (p≤0.05) lowers during extreme hot temperature in comparison to moderate period. Therefore, it could be concluded that variations in enzyme markers were associated with changes in environmental temperatures. Probably ETP were able to produce a profound effect on carbohydrate metabolism in sheep. Therfore it can be suggested that during the period of extreme temperature balanced ration must be provided to the animal along with proper management to decrease the severity of temperature impact.

scholarly journals Effects of 7°C environmental temperature acclimation during a 3-week training period

2020 ◽  
Vol 128 (4) ◽  
pp. 768-777
Author(s):  
Robert Shute ◽  
Katherine Marshall ◽  
Megan Opichka ◽  
Halee Schnitzler ◽  
Brent Ruby ◽  
...  
Keyword(s):  
Room Temperature ◽  
Environmental Temperature ◽  
Cellular Signaling ◽  
Temperature Acclimation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Training Adaptations ◽  
Before And After ◽  
The Impact ◽  
Environmental Temperatures

Cold environmental temperatures during exercise and recovery alter the acute response to cellular signaling and training adaptations. Approximately 3 wk is required for cold temperature acclimation to occur. To determine the impact of cold environmental temperature on training adaptations, fitness measurements, and aerobic performance, two groups of 12 untrained male subjects completed 1 h of cycling in 16 temperature acclimation sessions in either a 7°C or 20°C environmental temperature. Fitness assessments before and after acclimation occurred at standard room temperature. Muscle biopsies were taken from the vastus lateralis muscle before and after training to assess molecular markers related to mitochondrial development. Peroxisome proliferator-activated receptor-γ coactivator 1α ( PGC-1α) mRNA was higher in 7°C than in 20°C in response to acute exercise before training ( P = 0.012) but not after training ( P = 0.813). PGC-1α mRNA was lower after training ( P < 0.001). BNIP3 was lower after training in the 7°C than in the 20°C group ( P = 0.017) but not before training ( P = 0.549). No other differences occurred between temperature groups in VEGF, ERRα, NRF1, NRF2, TFAM, PINK1, Parkin, or BNIP3L mRNAs ( P > 0.05). PGC-1α protein and mtDNA were not different before training, after training, or between temperatures ( P > 0.05). Cycling power increased during the daily training ( P < 0.001) but was not different between temperatures ( P = 0.169). V̇o2peak increased with training ( P < 0.001) but was not different between temperature groups ( P = 0.460). These data indicate that a 3-wk period of acclimation/training in cold environmental temperatures alters PGC-1α gene expression acutely but this difference is not manifested in a greater increase in V̇o2peak and is dissipated as acclimation takes place. NEW & NOTEWORTHY This study examines the adaptive response of cellular signaling during exercise in cold environmental temperatures. We demonstrate that peroxisome proliferator-activated receptor-γ coactivator 1α mRNA is different between cold and room temperature environments before training but after training this difference no longer exists. This initial difference in transcriptional response between temperatures does not lead to differences in performance measures or increases in protein or mitochondria.

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