A method based on the familiar coupling azo dye technique has been devised for the study of enzyme distribution in thick specimens. Its application to the study of esterase distribution in whole tadpoles of Xenopus laevis is described in detail. It can also be used to show the distribution of alkaline phosphatase, both in Xenopus tadpoles and in limbs dissected from chick embryos. It has proved...

In supersymmetric theories, the occurrence of universal singlets is a delicate issue, because they usually induce tadpoles that destabilize the hierarchy. We study the effects of these tadpoles in supersymmetric hybrid inflation models. The resulting scenario is generically modified, but it is still possible to achieve inflation in a natural way. It is argued that singlets, despite the problems...

A mutant gene, Pale, (Pa) has been discovered in the discoglossid frog, Bombina orientalis. Breeding experiments indicate that the gene is recessive to the wild-type allele (P). Embryos, tadpoles and adults homozygous for the Pale gene are lighter in coloration than wild-type animals. Eggs produced by Pale females appear normally pigmented. Neural-retina defects were apparent in Pale tadpoles. ...

Most of the reproductive modes of frogs include an exotrophic tadpole, but a number of taxa have some form of endotrophic development that lacks a feeding tadpole stage. The dicroglossid frog genus Limnonectes ranges from China south into Indonesia. The breeding biologies of the approximately 60 described species display an unusual diversity that range from exotrophic tadpoles to endotrophic de...

Nonvanishing tadpoles and possible infinities associated in the multiparticle amplitudes are discussed with regard to the disk and RP 2 diagrams of the Type I ′ compactification. We find that the infinity cancellation of SO(32) type I theory extends to this case as well despite the presence of tadpoles localized in the D-brane worldvolume and the orientifold surfaces. Formalism of string S-matr...

—Tadpoles can generally increase their probability of survival in the presence of known predators by reducing their foraging activities or modifying their tail shape to increase swimming speed or lure attacks away from the head. However, it is unknown to what extent tadpoles can induce such behavioral and morphological plasticity in response to introduced predators. Lowland Leopard Frogs (Rana ...

ABSTRACT Predation is a strong driver for the evolution of prey behaviour. To properly assess actual risk predation, anuran tadpoles mostly rely on water-borne chemical cues, and their ability to evaluate environmental information even more crucial when potential predators consist unknown alien species. Behavioural plasticity – that is, capacity express changes in behaviour response different s...

We discuss the construction of sixand four-dimensional Type IIB orientifolds with vanishing untwisted RR tadpoles, but generically non-zero twisted RR tadpoles. Tadpole cancellation requires the introduction of D-brane systems with zero untwisted RR charge, but non-zero twisted RR charges. We construct explicit models containing branes and antibranes at fixed points of the internal space, or no...

Tadpoles of five anuran species were tested for preferences in the use of the eyes during inspection of their own visual image in a mirror. When tested in a tank with several small mirrors, tadpoles of five different species (Bufo bufo, Bufo viridis, Rana temporaria, Rana esculenta, Bombina variegata) preferentially approached and positioned themselves with the mirror located on their left side...

Maternal effects--where an individual's phenotype is influenced by the phenotype or environment of its mother--are taxonomically and ecologically widespread. Yet, their role in the origin of novel, complex traits remains unclear. Here we investigate the role of maternal effects in influencing the induction of a novel resource-use phenotype. Spadefoot toad tadpoles, Spea multiplicata, often devi...