Evolution of morphology and locomotor performance in anurans: relationships with microhabitat diversification.

The relationships between morphology, performance, behavior and ecology provide evidence for multiple and complex phenotypic adaptations. The anuran body plan, for example, is evolutionarily conserved and shows clear specializations to jumping performance back at least to the early Jurassic. However, there are instances of more recent adaptation to habit diversity in the post-cranial skeleton, including relative limb length. The present study tested adaptive models of morphological evolution in anurans associated with the diversity of microhabitat use (semi-aquatic arboreal, fossorial, torrent, and terrestrial) in species of anuran amphibians from Brazil and Australia. We use phylogenetic comparative methods to determine which evolutionary models, including Brownian motion (BM) and Ornstein-Uhlenbeck (OU) are consistent with morphological variation observed across anuran species. Furthermore, this study investigated the relationship of maximum distance jumped as a function of components of morphological variables and microhabitat use. We found there are multiple optima of limb lengths associated to different microhabitats with a trend of increasing hindlimbs in torrent, arboreal, semi-aquatic whereas fossorial and terrestrial species evolve toward optima with shorter hindlimbs. Moreover, arboreal, semi-aquatic and torrent anurans have higher jumping performance and longer hindlimbs, when compared to terrestrial and fossorial species. We corroborate the hypothesis that evolutionary modifications of overall limb morphology have been important in the diversification of locomotor performance along the anuran phylogeny. Such evolutionary changes converged in different phylogenetic groups adapted to similar microhabitat use in two different zoogeographical regions.

Pharmacoeconomics of intravenous antibiotic use in serious infection - abstract

A pharmacoeconomic study of 15 antibiotics available in Barbados was performed. The antibiotics studied were amoxycillin/clavulanate, ampicillin, ampicillin/sulbactam, cefazolin, cefotaxime, ceftazidime, ceftriaxone, clindamycin, cloxacillin, co-trimoxazole, gentamicin, irnipenem, metronidazole, piperacillin, piperacillin/tazobactam, and vancomycin. The costs of use of these compounds using a formula comprising eight categories: antibiotic purchase cost, maintenance of IV access, drug delivery cost, drug monitoring cost, dose readjustment, general monitoring cost, sharps disposal cost and adverse effects. The costs of adverse effects were not included in this study due to lack of accurate data. The total costs of antibiotic use (in Barbados dollars) ranged from $85.04 to $927.46 per five-day course. Generic compounds were less expensive ($85.04 - $236.02) than brand-name compounds ($212.25 - $927.46). Antibiotic purchase costs accounted for proportions of total costs ranging from 7 per cent to 93 per cent. Non-drug costs represented a much greater proportion of total costs of generic compounds. For most compounds the non-drug costs were related to the frequency of dosing, but for gentamicin the non-drug costs were relatively higher because of the need for monitoring serum gentamicin levels. Efficacy and freedom from side-effects will remain the most important determinants in the choice of antibiotic therapy. However, pharmacoeconomic analyses can provide clinicians with the information required to make cost-effective choices for treatment of their patients (AU)