Received September 16, 1992; accepted October 9, 1992; revised manuscript received December 1, 1992 We recently introduced a new technique, frequency-resolved optical gating (FROG), for directly determining the full intensity I(t) and phase p(t) of a single femtosecond pulse. By using almost any instantaneous nonlinearoptical interaction of two replicas of the ultrashort pulse to be measured, F...

The frogs of the Tropical and Subtropical lowland forests east of the Andes comprise a diverse assemblage whose basic Zoogeographie patterns are just beginning to be understood. Part of the problem in understanding the basic distributions has been the unequal representation of frog collections on a geographical basis. Recently, authors have been proposing some general distribution patterns, esp...

Urotensin II (UII) is a cyclic peptide initially isolated from the caudal neurosecretory system of teleost fish. Subsequently, UII has been characterized from a frog brain extract, indicating that a gene encoding a UII precursor is also present in the genome of a tetrapod. Here, we report the characterization of the cDNAs encoding frog and human UII precursors and the localization of the corres...

25 26 Short-term synaptic facilitation occurs during high frequency stimulation, is known to be dependent on 27 presynaptic calcium ions, and persists for tens of milliseconds after a presynaptic action potential. We 28 have used the frog neuromuscular junction as a model synapse for both experimental and computer 29 simulation studies aimed at testing various mechanistic hypotheses proposed to...

Frogs are well known to capture fast-moving prey by flicking their sticky tongues out of the mouth. This tongue projection behaviour happens extremely fast which makes frog tongues a biological high-speed adhesive system. The processes at the interface between tongue and prey, and thus the mechanism of adhesion, however, are completely unknown. Here, we captured the contact mechanics of frog to...

Several analytic techniques have been used to determine sexual dimorphism in vertebrate morphological measurement data with no emergent consensus on which technique is superior. A further confounding problem for frog data is the existence of considerable measurement error. To determine dimorphism, we examine a single hypothesis (Ho = equal means) for two groups (females and males). We demonstra...

Many microhylid frog species, such as the tomato frog, Dyscophus sp., have demonstrated ability to aim their tongues independently of head and jaw movements. However, a trade-off between tongue-aiming head-only aiming exists in which former allows for crypsis but lacks speed whereas latter is faster less accurate more noticeable prey. For frogs that can move heads, under what circumstances will...

OBJECTIVE To compare the transverse dental changes induced by the palatally applied Frog appliance and buccally applied Karad's integrated distalizing system (KIDS). METHODS We evaluated the pre- and post distalization orthodontic models of 39 patients, including 19 treated using the Frog appliance, which is palatally positioned (Frog group), and 20 treated using KIDS, which is buccally posit...

The fringe-lipped bat, Trachops cirrhosus, uses frog mating calls to detect and locate its prey. The túngara frog, Physalaemus pustulosus, a preferred prey species of this bat, produces two types of sexual advertisement calls, simple and complex, and both female frogs and predatory bats prefer complex calls to simple ones. Complex calls differ from simple ones in that they contain chucks: short...