Efficient induction of spawning of northern leopard frogs (Lithobates pipiens) during and outside the natural breeding season.

Background: Amphibian declines are now recognized globally. It is also well known that many anurans do not reproduce easily in captivity, especially when held over long periods, or if they require hibernation before breeding. A simple method to induce spawning and subsequent development of large numbers of healthy tadpoles is therefore required to meet research and conservation goals.

Hormonal induction of spawning in 4 species of frogs by coinjection with a gonadotropin-releasing hormone agonist and a dopamine antagonist.

Background: It is well known that many anurans do not reproduce easily in captivity. Some methods are based on administration of mammalian hormones such as human chorionic gonadotropin, which are not effective in many frogs. There is a need for simple, cost-effective alternative techniques to induce spawning.

An analysis of selection on a colour polymorphism in the northern leopard frog.

In this study, we investigated the role of selection in the maintenance of a dorsal colour polymorphism in natural populations of the northern leopard frog, Rana pipiens. We determined genetic structure both spatially and temporally from a suite of putatively neutral molecular markers and tested whether or not the colour locus exhibited patterns of genetic variation that differed from those of the neutral loci. Spatial genetic structure at the colour locus was indistinguishable from structure at neutral loci [95% confidence intervals of F(ST) (neutral) = (0.

Poor outcome of two children with relapsed state stage IV alveolar rhabdomyosarcoma after allogeneic stem cell transplantation.

The authors report on 2 boys, 11(1/2) and 13 years old, who received allogeneic stem cell transplantation (alloSCT) from their HLA-identical sibling after relapse of stage IV alveolar rhabdomyosarcoma. Both patients were transplanted in a non-remission status. After alloSCT both patients experienced disease progression at the primary tumor location sites and died due to the underlying disease 146 and 379 days after transplantation.

Influence of satellite groups on telechelic antimicrobial functions of polyoxazolines.

The antimicrobial activity of poly(alkyloxazoline) telechelics with one quaternary N,N-dimethyldodecylammonium (DDA) end group was found to be greatly controlled by the non-bioactive distal end group, the so-called satellite group. In systematic investigations, the nature of the latter groups was varied to explore the mechanism of the satellite effect. To this end, poly(2-alkyl-1,3-oxazoline)s (alkyl = ethyl, methyl) with a DDA-group at the terminating end and varying alkyl, aminoalkyl, and polyphenyloxazoline block satellite groups, have been synthesized.

Effective population sizes and temporal stability of genetic structure in Rana pipiens, the northern leopard frog.

Although studies of population genetic structure are very common, whether genetic structure is stable over time has been assessed for very few taxa. The question of stability over time is particularly interesting for frogs because it is not clear to what extent frogs exist in dynamic metapopulations with frequent extinction and recolonization, or in stable patches at equilibrium between drift and gene flow. In this study we collected tissue samples from the same five populations of leopard frogs, Rana pipiens, over a 22-30 year time interval (11-15 generations).

Traumatology of the traffic accident--dead people for the safety in traffic.

Since 1970, traumatomechanics has been a focal point in research at the Institute for Legal Medicine and Traffic Medicine in Heidelberg. Here, the main topics are the understanding of the interrelation between mechanical strain and the resulting degree of injury; at the forefront of all interest is the determination of the mechanical resilience in humans, their organs and tissues. Important are not only the means, but likewise the individual strain tolerance and the causes for its variability.

Marine biodiversity hotspots and conservation priorities for tropical reefs.

Coral reefs are the most biologically diverse of shallow water marine ecosystems but are being degraded worldwide by human activities and climate warming. Analyses of the geographic ranges of 3235 species of reef fish, corals, snails, and lobsters revealed that between 7.2% and 53.

The influence of mixed venous pO2 on the natriuretic activity of cat plasma.

Plasma was taken from anaesthetised cats with high or low mixed venous pO2. Different plasma fractions were then administered to anaesthetised rats to examine the effect on sodium excretion. It was found that only the low molecular weight fraction of the plasma from cast with high mixed venous pO2 showed any natriuretic activity.