Reduction in body size is a major response to climate change, yet evidence in globally imperiled amphibians is lacking. Shifts in average population body size could indicate either plasticity in the growth response to changing climates through changes in allocation and energetics, or through selection for decreased size where energy is limiting. We compared historic and contemporary size measurements in 15 Plethodon species from 102 populations (9450 individuals) and found that six species exhibited significant reductions in body size over 55 years. Biophysical models, accounting for actual changes in moisture and air temperature over that period, showed a 7.1-7.9% increase in metabolic expenditure at three latitudes but showed no change in annual duration of activity. Reduced size was greatest at southern latitudes in regions experiencing the greatest drying and warming. Our results are consistent with a plastic response of body size to climate change through reductions in body size as mediated through increased metabolism. These rapid reductions in body size over the past few decades have significance for the susceptibility of amphibians to environmental change, and relevance for whether adaptation can keep pace with climate change in the future.

The cardioprotective effects of short-term exercise against myocardial ischaemia-reperfusion injury in male and female rats were examined. We subjected male and female rats to 0 (Sed; n = 8 males and 8 females), 1 (1 day; n = 10 males and 8 females), or 5 (5 day; n = 6 males and 6 females) days of treadmill running. Langendorff-perfused hearts underwent 1 h of regional ischaemia and 2 h of reperfusion, and infarct size (expressed as a percentage of the zone at risk; ZAR), left ventricular pressure development, and coronary flow were measured for each heart. Preischaemic pressure development and coronary flow did not differ between the sexes nor were they influenced by exercise. Sed females had significantly smaller infarct sizes (25 ± 3%) than Sed male hearts (37 ± 3%; P < 0.001). Short-term running significantly reduced infarct size following 1 day (27 ± 3%; P < 0.05) and 5 days (30 ± 4%; P < 0.10) of exercise in males. One day of running did not reduce infarct size in females (19 ± 3%; P = NS), but 5 day females did show a significant reduction in infarct size (13 ± 2%; P < 0.05). There was no relationship between postischaemic coronary vascular hyperaemia and infarct size across sexes or exercise training groups. Hearts from Sed females exhibited significantly higher manganese superoxide dismutase (MnSOD) protein expression than hearts from Sed males, but short-term exercise (neither 1 nor 5 days) did not alter MnSOD protein in either sex. Increased sarcolemmal ATP-sensitive K + (K ATP ) channel subunit protein expression (SUR2A and/or K ir 6.2) correlated closely with sex-dependent and exercise-acquired protection against myocardial infarction. These data indicate that: (1) sex-dependent and exercise-induced differences in the susceptibility of the heart to ischaemia-reperfusion injury are not associated with improved coronary flow or postischaemic hyperaemia; (2) increased MnSOD protein expression is not necessary for exercise-induced protection from infarction; and (3) one possible mechanism for sex-dependent and exercise-mediated reductions in infarct size involves an increased protein expression of cardiac sarcolemmal K ATP channels.

Background: There is a negative relationship between education and religiosity and a positive relationship between education and acceptance of evolution, but how this manifests in college students who differ in degree of religiosity and prior educational experiences is unclear. We focused our study on the relative importance of education and religion on evolution understanding for college students at a large, public university in the Deep South. Methods: We used a structural equation model incorporating both acceptance and knowledge of evolution to evaluate the relative influence of religion and education on evolution understanding of 2,999 surveyed students. We further focused on acceptance of evolution and academic level, college major, high school experience, religion, and religiosity. We conducted pre and post course evaluations in three biology classes, and finally we tested the relationships between the quality of K-12 state science standards and states' religiosity and educational attainment. Results: We found that the degree of religiosity mattered significantly more than education when predicting students' understanding of evolution. When we focused on acceptance of evolution only, students taught evolution or neither evolution nor creationism in high school had significantly higher acceptance than those taught both evolution and creationism or just creationism. Science majors always outscored non-science majors, and not religious students significantly outperformed religious students. Highly religious students were more likely to reject evolution even though they understood that the scientific community accepted the theory of evolution. Overall, students in two of three biology classes increased their acceptance of evolution, but only those students that seldom/never attended religious services improved. K-12 state science standard grades were significantly and negatively correlated with measures of state religiosity and significantly and positively correlated with measures of state educational attainment.

The use of short-term (1-5 days) treadmill running is becoming increasingly common as a model to study physiological adaptations following the exercise. Although the beneficial effects of acute exercise seem clear, a paucity of data exist describing potential markers of stress in response to forced running. We subjected male and female Sprague-Dawley rats to 0, 1, 2, 5, or 10 days of treadmill running. Twenty-four to 32 h after the last bout of exercise animals were killed and examined for training-induced changes in several physiological variables. No effect of skeletal citrate synthase activity was observed in the male animals after any duration, and only at 10 days of running did females show a significant increase in citrate synthase. Myocardial heat shock protein 72 (HSP72) content was higher in male rats than female rats, and exercise led to increased HSP72 in both sexes, although the time course was different between males and females. Animals displayed several markers of systemic stress in response to the treadmill running, and this was done in a sex-dependent manner. Serum corticosterone was significantly elevated in both sexes 24 h after exercise in three of four exercise groups. Corticosterone-binding globulin was higher in females, and decreased after running in female rats. Body and spleen weights decreased in males (but not females) in response to the exercise training, and running did not alter adrenal gland weights in either sex. These data indicate that in response to short-term treadmill running both male and female rats show signs of systemic stress, but that the pattern of changes occurs in a sex-specific manner.