Sexual dimorphism of body size and shell shape in European tortoises

Adult body size and shape were examined in almost 1400 individuals of the tortoises Testudo graeca , T. hermanni and T. marginata from Greece. The size at maturity was greater in females than in males in all three species. Maximum and mean adult sizes were also greater in females than in males in T. graeca and T. hermanni . Males grew to a larger size than females in T. marginata , and mean adult size was similar in the sexes in this species. Sexual dimorphism of shape (adjusted for size covariate) was shown in most of the characters examined, and the degree of this dimorphism differed significantly among the three species. Differences were related to their contrasting courtship behaviours: horizontal head movements and severe biting in T. marginata , vertical head bobs and carapace butting in T. graeca , and mounting and tail thrusting in T. hermanni . There was no difference in the frequency of observations of courtship or fighting among the three species, but courtship was about 10 times more common than combat in males. All species showed greatest courtship activity in autumn; copulation was rarely observed in T. hermanni (only 0.36% of courting males) and not seen in the other species in the field. Observations made throughout the activity season indicated that feeding was equally common in males and females in all three species. Differences in shape were more likely to be the result of sexual selection than of natural selection for fecundity. Detailed predictions are made for sexual dimorphism of other characters in these species.     

Metabolic effects of physiological levels of caffeine in myotubes

Caffeine has been shown to stimulate multiple major regulators of cell energetics including AMP-activated protein kinase (AMPK) and Ca²⁺/calmodulin-dependent protein kinase II (CaMKII). Additionally, caffeine induces peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and mitochondrial biogenesis. While caffeine enhances oxidative metabolism, experimental concentrations often exceed physiologically attainable concentrations through diet. This work measured the effects of low-level caffeine on cellular metabolism and gene expression in myotubes, as well as the dependence of caffeine’s effects on the nuclear receptor peroxisome proliferator-activated receptor beta/delta (PPARβ/δ). C2C12 myotubes were treated with various doses of caffeine for up to 24 h. Gene and protein expression were measured via qRT-PCR and Western blot, respectively. Cellular metabolism was determined via oxygen consumption and extracellular acidification rate. Caffeine significantly induced regulators of mitochondrial biogenesis and oxidative metabolism. Mitochondrial staining was suppressed in PPARβ/δ-inhibited cells which was rescued by concurrent caffeine treatment. Caffeine-treated cells also displayed elevated peak oxidative metabolism which was partially abolished following PPARβ/δ inhibition. Similar to past observations, glucose uptake and GLUT4 content were elevated in caffeine-treated cells, however, glycolytic metabolism was unaltered following caffeine treatment. Physiological levels of caffeine appear to enhance cell metabolism through mechanisms partially dependent on PPARβ/δ.     

Home range area in the tortoise Testudo hermanni in relation to habitat complexity: implications for conservation of biodiversity

The tortoise Testudo hermanni is endangered by habitat fragmentation and loss in western Europe, where its high public profile and specific conservation projects make this a flagship species. Studies of movement in the peak reproductive season (June) showed that home ranges were substantially larger in France than in Greece. This difference was due to the intensity of use of the home range, not to the distance moved which was remarkably similar in the two areas. There was no sexual difference in home range area. The home range was therefore not large in France because of movement to nesting sites, but rather for utilization of the greater habitat complexity there. The need for reserves to include different vegetation types makes conservation of T. hermanni in France more difficult. Conversely, the need for large reserves increases its value as an umbrella species for conservation of biodiversity.     

Diazepam in Labour: Its Metabolism and Effect on the Clinical Condition and Thermogenesis of the Newborn

Following the administration of diazepam to mothers in labour the clinical effects, changes in thermogenesis, and metabolism of the drug in the newborn were observed under carefully controlled conditions. A total maternal dose of 30 mg or less in the 15 hours before delivery had little effect on the infants'' state. Larger doses, however, were accompanied by low Apgar scores at birth, apnoeic spells, hypotonia, reluctance to feed, and an impaired metabolic response to a cold stress. Measurement of plasma levels of diazepam and its active metabolite showed that both products were detectable in significant concentrations in some infants for up to eight days. We conclude that greater care should be taken in the use of this otherwise effective drug for the treatment of pre-eclampsia.     

Velvet worm (Phylum Onychophora) on a sand island,in a wetland: Flushed from a Pleistocene refuge by recent rainfall?

Velvet worms (Onychophora) are restricted to moist, humid microclimates, but are poorly known from south‐east Queensland, Australia, where they are typically rainforest fauna. We made the unlikely observation of one of these invertebrates clinging to floating debris in a wetland on North Stradbroke Island. Palaeoecology of this wetland reveals that it once was within rainforest and has remained moist for at least the past 80 000 years, thus potentially harbouring an onychophoran population as a relic of a past broader, rainforest distribution. The presence of this animal, floating in the wetland, can be explained by recent climate, since the wetland filled following heavy rainfall shortly before the observation. This highlights the importance of groundwater‐fed wetlands as evolutionary refugia for moisture‐dependent biota.