In addition to its well-known role as an adipostat in adult mammals, leptin has diverse physiological and developmental actions in vertebrates. Leptin has been shown to promote development of hypothalamic circuits and to induce mitosis in different brain areas of mammals. We investigated the ontogeny of leptin mRNA, leptin actions on cell proliferation in the brain, and gene expression in the p...

Using phylogeny-based methods to identify evolutionary transitions has become an integral part of evolutionary biology. Here, we demonstrate the potential for these methods to give statistically well-supported but misleading inferences about character evolution. We also show how inferences of character evolution can be informed using GIS-based methods to reconstruct ancestral environmental regi...

Prolactin (PRL) has, for some years, been considered to be the 'juvenile hormone' in amphibians. Recently, growth hormone (GH) has been proposed as another candidate, because in the larval stages the expression of the mRNA GH is high but it is downregulated in the climax stages of metamorphosis or following treatment with thyroid hormone. In the present study, we investigated whether GH promote...

We investigate the quantum structure of Witten’s cubic open bosonic string field theory by computing the one-loop contribution to the open string tadpole using both oscillator and conformal field theory methods. We find divergences and a breakdown of BRST invariance in the tadpole diagram arising from tachyonic and massless closed string states, and we discuss ways of treating these problems. F...

Dendrobatidae (dart-poison frogs) exhibit some of the most complex spatial behaviors among amphibians, such as territoriality and tadpole transport from terrestrial clutches to widely distributed deposition sites. In species that exhibit long-term territoriality, high homing performance after tadpole transport can be assumed, but experimental evidence is lacking, and the underlying orientation ...

We analyze the latent heat and surface tension at the SU(3) deconfinement phase transition with tree level and tadpole improved Symanzik actions on lattices with temporal extent N τ = 3 and 4 and spatial extent N σ /N τ = 4, 6 and 8. In comparison to the standard Wilson action we do find a drastic reduction of cutoff effects already with tree level improved actions. On lattices with temporal ex...

the tadpole shrimp of genus triops is a well-known living fossil whose fundamental morphology has been unchanged for 220 million years. we collected specimens of triops cancriformis in temporary water bodies near the southern part of urmia lake (in the fall of 2005). some biological characteristics of this triops were investigated. the feeding re-gime of t. cancriformis was found to be related ...

Traditional methods for identifying individual amphibians in capture–mark–recapture (CMR) studies have been primarily confined to post-metamorphic stages, using artificial markers that come with a variety of limitations. An alternative may open CMR earlier life stages involves the use species' natural external photo-based identification. In this study, we investigated whether it was possible di...

A bstract We study tadpole potentials of non-supersymmetric strings, resorting to a first-order formalism known in the literature as fake supersymmetry. present detailed analysis for vacua with only gravity and dilaton, displaying obstructions that forbid simplest inclusion form fluxes. Our focus is on codimension-one vacua, which we propose definition energy might be suitable stability argumen...