Fossil frogs from the central highlands of Papua New Guinea

Characteristic features of the pelves of 15 species of extant New Guinean highland frogs (Hylidae and Microhylidae) are described and figured. Ilia among species in these families were found to be relatively invariate with similar sized species often indistinguishable; thus fossil species diversity is therefore likely to be underestimated in such deposits. Nine-two disarticulated ilia from the highland Nombe rockshelter deposit represent a minimum of six species: two Hylidae and four Microhylidae; most of these ilia were deposited in the late Pleistocene before significant human activity at the site. Problems of drawing conclusions about the Pleistocene frog fauna of the area, especially what the main predator was, from such a small sample and limited understanding of the site taphonomy are discussed. © AAP

The physician-patient relationship revisited: the patient’s view

Physician-patient relationship, Health behavior, Bivariate probit panel, I12, C33, D82,

Biophysical properties and functional significance of stem water storage tissues in Neotropical savanna trees

Biophysical characteristics of sapwood and outer parenchyma water storage compartments were studied in stems of eight dominant Brazilian Cerrado tree species to assess the impact of differences in tissue capacitance on whole-plant water relations. The rate of decline in tissue water potential  with relative water content was greater in the outer parenchyma than in the sapwood for most of the species, resulting in tissue-and species-specific differences in capacitance. Sapwood capacitance on a tissue volume basis ranged from 40 to 160 kg m-3 MPa-1, whereas outer parenchyma capacitance ranged from 25 to only 60 kg m-3 MPa-1. In addition, osmotic potentials at full turgor and at the turgor loss point were more negative for the outer parenchyma compared to the sapwood, and the maximum bulk elastic modulus was higher for the outer parenchyma than for the sapwood. Sapwood capacitance decreased linearly with increasing sapwood density across species, but there was no significant correlation between outer parenchyma capacitance and tissue density. Midday leaf water potential, the total hydraulic conductance of the soil/leaf pathway and stomatal conductance all increased with stem volumetric capacitance, or with the relative contribution of stored water to total daily transpiration. However, the difference between the predawn water potential of non-transpiring leaves and the weighted average soil water potential, a measure of the water potential disequilibrium between the plant and soil, increased asymptotically with total stem capacitance across species, implying that overnight recharge of water storage compartments was incomplete in species with greater capacitance. Overall, stem capacitance contributes to homeostasis in the diurnal and seasonal water balance of Cerrado trees.Fil: Scholz, Fabian Gustavo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. University of Miami; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bucci, Sandra Janet. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Goldstein, Guillermo Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Meinzer, Frederick. Department of Agriculture Forest Service; Estados UnidosFil: Franco, Augusto. Universidade do Brasília; BrasilFil: Miralles Wilhem, Fernando. Florida International University; Estados Unido