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The aim of this study was to examine the effects of cold exposure on rat skeletal muscle fiber type, according to myosin heavy chain ( MyHC) isoform and metabolism-related factors. Male Wistar rats (7 weeks old) were housed individually at 4 ± 2°C as a cold-exposed group or at room temperature (22 ± 2°C) as a control group for 4 weeks. We found that cold exposure significantly increased the slow-type MyHC1 content in the soleus muscle (a typical slow-type fiber), while the intermediate-type MyHC2A content was significantly decreased. In contrast to soleus, MyHC composition of extensor digitorum longus ( EDL, a typical fast-type fiber) and gastrocnemius (a mix of slow-type and fast-type fibers) muscle did not change from cold exposure. Cold exposure increased mRNA expression of mitochondrial uncoupling protein 3 ( UCP3) in both the soleus and EDL. Cold exposure also increased mRNA expression of myoglobin, peroxisome proliferator-activated receptor gamma coactivator 1α ( PGC1α) and forkhead box O1 ( FOXO1) in the soleus. Upregulation of UCP3 and PGC1α proteins were observed with Western blotting in the gastrocnemius. Thus, cold exposure increased metabolism-related factors in all muscle types that were tested, but MyHC isoforms changed only in the soleus. [ABSTRACT FROM AUTHOR]

Hibernation and daily torpor (i.e. temporal heterothermy) have been reported in many marsupial species of diverse families and are known to occur in ∼15% of all marsupials, which is a greater proportion than the percentage of heterothermic placentals. Therefore, we aimed to gather data on heterothermy, including minimal body temperature, torpor metabolic rate and torpor bout duration for marsupials, and relate these physiological variables to phylogeny and other physiological traits. Data from published studies on 41 marsupial species were available for the present analysis. Heterothermic marsupials ranged from small species such as planigales weighing 7 g to larger species such as quolls weighing up to 1000 g. We used the marsupial phylogeny to estimate various heterothermic traits where the current dataset was incomplete. The torpor metabolic rate in relation to basal metabolic rate (%) ranged from 5.2 to 62.8% in daily heterotherms and from 2.1 to 5.2% in marsupial hibernators, and was significantly correlated with the minimum body temperature in daily heterotherms ( R2 = 0.77, P < 0.001), but not in hibernators ( R2 = 0.10, P > 0.05). The mean torpor bout duration ranged from 2 to 15 h in daily heterotherms and from 85 to 342 h in hibernators, and decreased significantly with increasing minimum body temperature in daily heterotherms ( R2 = 0.31, P < 0.001), but was not significant in hibernators. Our results show that phylogeny has a significant influence on nearly all analysed individual traits and relationships between traits in daily heterotherms ( n = 35), but not in hibernators ( n = 6). However, allometric analyses show that many of the physiological parameters scale differently between hibernators and daily heterotherms. [ABSTRACT FROM AUTHOR]

Recent studies have documented high levels of bat fatalities at wind-energy facilities built on forested ridgetops in the eastern United States. To better understand the influence of temperature and elevation on bat activity levels, and the possible relationship of these factors to bat fatalities at wind facilities, we sampled bat activity and insect abundance along an elevational gradient at 3 study areas in northeastern Pennsylvania. Bat activity was sampled with an AR125 acoustic detector, and insect abundance was sampled with a black-light trap. We developed a negative binomial regression model to assess the relationship between bat activity and temperature, elevation, and insect abundance. We also assessed a hypothesized association between the occurrence of temperature inversions and increased bat activity at higher elevations. We found a significant positive association between bat activity and temperature (P < 0.001), with the effect of temperature being greater at higher elevations (P = 0.021). Contrary to predictions, there was a significant negative relationship between bat activity and insect biomass (P < 0.001), and the association between bat activity and the occurrence of temperature inversions was not significant (P = 0.1). Although we did find significantly greater bat activity at higher temperatures, and an interaction between temperature and elevation, our results do not support temperature inversions as a factor in bat fatalities at wind-energy facilities on forested ridgetops in the eastern US. [ABSTRACT FROM AUTHOR]

Townsend's big-eared bat (Corynorhinus townsendii) is a widespread species of special concern that hibernates in large numbers in the lava-tube caves of southeastern Idaho. We measured 24 habitat variables describing landscape-level, physical, and microclimate characteristics of 13 caves and identified at least three that were useful for predicting winter occupancy by C. townsendii. In univariate analyses, distance to ephemeral water was the only variable that significantly predicted occupancy. Temperature and dewpoint were non-significantly higher in occupied than unoccupied caves. Our index of human disturbance was not associated with winter occupancy as observed in other studies. A multivariate (discriminant) analysis identified three characteristics that significantly and best predicted occupancy by big-eared bats in our sample of caves: (1) greater distance to ephemeral water, (2) the presence of a collapse or constriction, and (3) lower mean height. Although not included in our mostpredictive multivariate model, high minimum relative humidity was significantly associated with caves that had a collapse or constriction. Our study suggests that both the landscape surrounding the cave and its physical and microclimate characteristics play a role in the suitability of caves as overwintering sites for Townsend's big-eared bats. [ABSTRACT FROM AUTHOR]

Models capturing the full effects of weather conditions on animal populations are scarce. Here we decompose yearly temperature and rainfall into mean trends, yearly amplitude of change and residual variation, using daily records. We establish from multi-model inference procedures, based on 1125 life histories (from 1987 to 2008), that European badger (Meles meles) annual mortality and recruitment rates respond to changes in mean trends and to variability in proximate weather components. Variation in mean rainfall was by far the most influential predictor in our analysis. Juvenile survival and recruitment rates were highest at intermediate levels of mean rainfall, whereas low adult survival rates were associated with only the driest, and not the wettest, years. Both juvenile and adult survival rates also exhibited a range of tolerance for residual standard deviation around daily predicted temperature values, beyond which survival rates declined. Life-history parameters, annual routines and adaptive behavioural responses, which define the badgers’ climatic niche, thus appear to be predicated upon a bounded range of climatic conditions, which support optimal survival and recruitment dynamics. That variability in weather conditions is influential, in combination with mean climatic trends, on the vital rates of a generalist, wide ranging and K-selected medium-sized carnivore, has major implications for evolutionary ecology and conservation. [ABSTRACT FROM AUTHOR]

Models capturing the full effects of weather conditions on animal populations are scarce. Here we decompose yearly temperature and rainfall into mean trends, yearly amplitude of change and residual variation, using daily records. We establish from multi-model inference procedures, based on 1125 life histories (from 1987 to 2008), that European badger (Meles meles) annual mortality and recruitment rates respond to changes in mean trends and to variability in proximate weather components. Variation in mean rainfall was by far the most influential predictor in our analysis. Juvenile survival and recruitment rates were highest at intermediate levels of mean rainfall, whereas low adult survival rates were associated with only the driest, and not the wettest, years. Both juvenile and adult survival rates also exhibited a range of tolerance for residual standard deviation around daily predicted temperature values, beyond which survival rates declined. Life-history parameters, annual routines and adaptive behavioural responses, which define the badgers’ climatic niche, thus appear to be predicated upon a bounded range of climatic conditions, which support optimal survival and recruitment dynamics. That variability in weather conditions is influential, in combination with mean climatic trends, on the vital rates of a generalist, wide ranging and K-selected medium-sized carnivore, has major implications for evolutionary ecology and conservation. [ABSTRACT FROM AUTHOR]

Abstract: Temperature is known to influence inflammatory signalling in mammals, but far less understood in fish. The aim of the present study was to explore the potential effects of temperature on innate immune signalling in head kidney and leukocyte populations of the economically important southern bluefin tuna through the identification and utilization of gene expression targets in vitro. Here, we identified the mRNA sequences of five potential inflammatory mediators – TNFα (1 and 2), IL-1β, IL-8, and Cox2 – and demonstrate induction of four – TNFα (2), IL-1β, IL-8, and Cox2 – following LPS stimulation of both peripheral blood leukocytes and head kidney homogenates in vitro by real-time quantitative PCR. Comparison of transcriptional expression in cultures held at 18 and 25 °C (both within the presumed natural temperature range of this heterothermic species) showed accelerated transcription of cytokines TNFα, IL-1β and IL-8 following LPS stimulation at 25 °C in both tissue types. Peak induction reached comparable levels for each transcript at both temperatures during the 24 h test period with only limited (if any) protraction in expression resulting from cold temperature (18 °C) incubation. Partial mRNA sequences were also identified for both the constitutively expressed and heat inducible chaperone proteins Hsc70 and Hsp70, and 24 h incubation at 25 °C was sufficient to induce Hsp70 transcription in leukocyte but not in head kidney cell populations. Taken together these findings suggest that temperature exerts influence in the timing but not the degree of an innate inflammatory response in bluefin tuna and that different cell populations have differential responsiveness to heat shock in this heterothermic species. Further, LPS stimulation failed to induce Hsp70 at either incubation temperature in leukocytes; whereas 25 °C incubation caused Hsp70 up-regulation in leukocytes with or without the presence of LPS. This suggests that Hsp70 does not play a direct role in immune responsiveness for this species and that an environmental temperature of 25 °C in excess of 24 h initiates a cellular stress response in blood cells of this organism. Lastly, a strong correlation between Hsp70 and IL-8 transcriptional expression was observed following LPS/heat shock stimulation of leukocytes and five potential heat shock response elements were subsequently identified on the gene promoter region of IL-8 indicating that heat shock co-activation of this chemokine previously identified in mammals is also likely present in fish. [Copyright &y& Elsevier]

The pregnancy results of 17337 inseminations carried out in a dairy herd near Cairo over a period of 12 years were retrospectively analyzed in relation to environmental temperature and temperature-humidity index (THI). The overall average of pregnancy rates to all inseminations was significantly (P<0.01) lower in pluriparous cows (31.0%) than in heifers (63.5%). Stress of lactation, propensity for clinical and subclinical mastitis and problems associated with calving are possible underlying causes. In cows, the month of insemination significantly (P<0.05) influenced the pregnancy rate. A substantial decrease of pregnancy rates from 34.1% in May to 15.7% in July as the maximum environmental temperature increased from 33.3 °C to 36.3 °C and mean THI increased from 69 to 74 was recorded. In spite of the slight increase in pregnancy rates after July, it remained low during autumn referring to the carryover effects of the summer heat load. This resulted in significantly (P<0.05) lower pregnancy rates during summer (21.2%) and autumn (24.4%) than in winter (39.1%) and spring (37.2%). Maximum environmental temperature and mean THI accounted for 72% and 82%, respectively, of the variations in pregnancy rates. The average number of inseminations per conception was the lowest between January and April (2.4±0.2 to 2.6±0.2). This was followed by a significant (P<0.05) increase in this parameter (from 2.9±0.6 in May to 6.4±1.9 in July) coinciding with increased maximum environmental temperature to reach its peak in July. The overall average number of inseminations per conception in cows was 3.2±0.4. In heifers, the pregnancy rate was high (56.9 to 69.8%) throughout the year with no significant differences between months or seasons of insemination. Better efficiency of heifers at thermoregulation compared with pluriparous cows may be implicated. The average number of inseminations per conception in heifers was 1.6±0.04. [ABSTRACT FROM AUTHOR]

The article discusses a study which showed how external parameters such as snow and temperature can influence diurnal activities including feeding behavior, heart rate and dominance behaviour of female reindeer in a fenced pasture area during winter. The hierarchy was studied between two study periods within a group of female reindeer. The study found new knowledge about the dominance relationships, competition and feeding activities among deer in winter conditions, which is said to be important in reindeer herding management.

A study was carried out to assess the influence of summer stress and effect of supplementation of vitamin E and selenium during different season on serum enzyme activities, i.e., aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) in Hallikar cattle. In the control group, activities of AST, ALT and ALP were significantly (P<0.05) higher during the summer season compared to winter season and rainy season. Further, the activity of all the enzymes were significantly (P<0.05) reduced in supplemented group compared to control group during summer, winter and rainy season. [ABSTRACT FROM AUTHOR]

The article focuses on the impact of climate change in the population of walruses in Arctic region. Topics discussed hypothesized mechanisms include retreat of sea ice over deep Arctic Ocean basin which forces walruses to use land-based haulouts, decline of sea ice which reduces access to prey resulting from adult female body condition, and impacts of sea ice decline on females and young animals.

Embedding temperature sensors within textiles provides an easy method for measuring skin temperature. Skin temperature measurements are an important parameter for a variety of health monitoring applications, where changes in temperature can indicate changes in health. This work uses a temperature sensing yarn, which was fully characterized in previous work, to create a series of temperature sensing garments: armbands, a glove, and a sock. The purpose of this work was to develop the design rules for creating temperature sensing garments and to understand the limitations of these devices. Detailed design considerations for all three devices are provided. Experiments were conducted to examine the effects of contact pressure on skin contact temperature measurements using textile-based temperature sensors. The temperature sensing sock was used for a short user trial where the foot skin temperature of five healthy volunteers was monitored under different conditions to identify the limitations of recording textile-based foot skin temperature measurements. The fit of the sock significantly affected the measurements. In some cases, wearing a shoe or walking also heavily influenced the temperature measurements. These variations show that textile-based foot skin temperature measurements may be problematic for applications where small temperature differences need to be measured. [ABSTRACT FROM AUTHOR]

Species selection, covariation of species' traits with their net diversification rates, is an important component of macroevolution. Most studies have relied on indirect evidence for its operation and have not quantified its strength relative to other macroevolutionary forces. We use an extension of the Price equation to quantify the mechanisms of body size macroevolution in mammals from the latest Palaeocene and earliest Eocene of the Bighorn and Clarks Fork Basins of Wyoming. Dwarfing of mammalian taxa across the Palaeocene/Eocene Thermal Maximum (PETM), an intense, brief warming event that occurred at approximately 56 Ma, has been suggested to reflect anagenetic change and the immigration of small bodied-mammals, but might also be attributable to species selection. Using previously reconstructed ancestor-descendant relationships, we partitioned change in mean mammalian body size into three distinct mechanisms: species selection operating on resident mammals, anagenetic change within resident mammalian lineages and change due to immigrants. The remarkable decrease in mean body size across the warming event occurred through anagenetic change and immigration. Species selection also was strong across the PETM but, intriguingly, favoured larger-bodied species, implying some unknown mechanism(s) by which warming events affect macroevolution. [ABSTRACT FROM AUTHOR]