Chondrocranium and visceral skeleton of Atelopus tricolor and Atelophryniscus chrysophorus

Atelopus tricolor and Atelophryniscus chrysophorus have gastromyzophorous tadpoles. Aside from specific differences, the larval chondrocrania and visceral skeletons show several shared character states, including an almost quadrangular, open chondrocranium , cornua trabeculae with expanded tips, cartilago suprarostralis as a single element, a posteriorly projected arcus subocularis quadrati, a closed muscular tunnel, and a simplified branchial basket, with only three pairs of ceratobranchiales. They are compared with diverse character states of suctorial larvae considering them as causally related to the stream life adaptations

Description of the Tadpole of \u3cem\u3eAtelopus tricolor\u3c/em\u3e

Tadpoles of Atelopus belong to the gastromyzophorous guild of exotrophic larvae (Altig and Johnston, 1989), and are characterized by the presence of a conspicuous abdominal sucker and an expanded oral disc. The larvae of several Atelopus species have been described previously: A. varius (Starrett, 1967); A. certus, A. ignescens, and A. spumarius (Duellman and Lynch, 1969); A. cruciger (Mebs, 1980); A. flavescens (Lescure, 1981); A. peruensis (Gray and Cannatella, 1985); and A. subornatus (Lynch, 1986). These represent about 15% of the known species in the genus (Frost, 1985; Duellman, 1993). Although Atelopus tricolor was originally described at the beginning of the century (Boulenger, 1902), it is a poorly known species. It has been reported from only a few localities from southern Peru (type locality: Marcapata Valley, Departamento Cuzco), to Departamento Cochabamba, Bolivia (Fugler, 1984; De la Riva, 1990; Reynolds and Foster, 1992), at elevations of 600-2100 m (Duellman, 1979). Herein we characterize and illustrate the tadpole of Ate/opus tricolor

The Identity of the Crackling, Luminescent Frog of Suriname (\u3cem\u3eRana typhonia\u3c/em\u3e Linnaeus, 1758) (Amphibia, Anura)

Review of the literature and recently available field notes from the collector of the type allows a reconsideration of the identity of the Linnaean name Rana typhonia. We provide evidence to demonstrate that the Linnaean species is neither a bufonid nor an Asiatic ranid, but a Neotropical hylid. Subsequently, we consider Rana typhonia as an older synonym of Rana venulosa Laurenti, 1768, redescribing its holotype under the new combination, Trachycephalus typhonius (Linnaeus, 1758)

Assessment of corneal biomechanical properties and intraocular pressure in myopic Spanish healthy population

Purpose. To examine biomechanical parameters of the cornea in myopic eyes and their relationship with the degree of myopia in a western healthy population. Methods. Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann correlated intraocular pressure (IOP), and corneal compensated IOP (IOPcc) were measured using the ocular response analyzer (ORA) in 312 eyes of 177 Spanish subjects aged between 20 and 56 years. Refraction was expressed as spherical equivalent (SE), which ranged from 0 to -16.50 diopters (D) (mean: -3.88 ± 2.90 D). Subjects were divided into four groups according to their refractive status: group 1 or control group: emmetropia (-0.50 = SE 0.05); nevertheless, IOPcc was significantly higher in the moderatelymyopic (15.47±2.47mmHg) and highlymyopic (16.14± 2.59mmHg) groups than in the emmetropia (15.15 ± 2.06mmHg) and low myopia groups (14.53 ± 2.37mmHg). No correlation between age and the measured parameters was found. CH and IOPcc were weakly but significantly correlated with SE (¿ = 0.171, ¿ = 0.002 and ¿ = -0.131, ¿ = 0.021, resp.). Conclusions. Present study showed only a very weak, but significant, correlation between CHand refractive error, with CH being lower in both moderately and highlymyopic eyes than that in the emmetropic and low myopic eyes.These changes in biomechanical properties of the cornea may have an impact on IOP measurement, increasing the risk of glaucom

In vitro effects of fungicides on the fungus Haliphthoros philippinensis

Pure cultures of Haliphthoros philippinensis, isolated from infected Penaeus monodon larvae, were exposed for 24 hours to varying concentrations of antifungal agents. The efficiency of each agent to inhibit sporulation and mycelial growth was measured. Effects on P. monodon eggs and larvae were also investigated. It is concluded that preliminary bioassay of larval tolerance to the suggested effective doses should always be made prior to prophylaxix or therapeutic applications

In-vitro effect of fungicides on hyphal growth and sporogenesis of Lagenidium sp. isolated from Penaeus monodon larvae and Scylla serrata eggs

The sensitivity of Lagenidium, isolated from Penaeus monodon, Scylla serrata , to 34 antimycotics was determined. Effects on the development of vesicles, zoospores and mycelial growth were evaluated. Although mycoidal levels of the chemicals tested will be ideal for lethal treatment on control of the fungus, the high dose required may be lethal to the host, thus the use of mycostatic concentrations is more practical. Treatments of rearing water containing larvae, adult shrimps or crabs should be done only after preliminary tolerance experiments using at least the mycostatic dose prove to be safe for the hosts. Mycocidal doses can be used for determining disinfection doses of equipment and facilities used in rearing procedures as well as for destroying batches of infected larvae

The Identity of \u3cem\u3eZachaenus roseus\u3c/em\u3e Cope, 1890 (Anura: \u3cem\u3eSpecies Inquirenda\u3c/em\u3e)

Zachaenus roseus Cope, 1890, has puzzled systematists working in southern South America. A single individual, the holotype, has ever been collected and this specimen is in extremely poor preservation condition. Herein, the precise location of the type locality of Z. roseus is determined based on a historical review of the literature. Furthermore, following a careful comparison with all species that inhabit the southern austral forest, and that could potentially correspond to Zachaenus roseus, we conclude that this taxon is placed in the synonymy of Eupsophus calcaratus (Günther, 1881

Molecular-orbital Studies Via Satellite-free X-ray Fluorescence: Cl-K Absorption and K–Valence-level Emission Spectra of Chlorofluoromethanes

X-ray absorption and emission measurements in the vicinity of the chlorine K edge of the three chlorofluoromethanes have been made using monochromatic synchrotron radiation as the source of excitation. By selectively tuning the incident radiation to just above the Cl 1s single-electron ionization threshold for each molecule, less complex x-ray-emission spectra are obtained. This reduction in complexity is attributed to the elimination of multielectron transitions in the Cl K shell, which commonly produce satellite features in x-ray emission. The resulting satellite-free x-ray-emission spectra exhibit peaks due only to electrons in valence molecular orbitals filling a single Cl 1s vacancy. These simplified emission spectra and the associated x-ray absorption spectra are modeled using straightforward procedures and compared with semiempirical ground-state molecular-orbital calculations. Good agreement is observed between the present experimental and theoretical results for valence-orbital energies and those obtained from ultraviolet photoemission, and between relative radiative yields determined both experimentally and theoretically in this work

The identity of Zachaenus roseus Cope, 1890 (Anura: species inquirenda)

Zachaenus roseus Cope, 1890, has puzzled systematists working in southern South America. A single individual, the holotype, has ever been collected and this specimen is in extremely poor preservation condition. Herein, the precise location of the type locality of Z. roseus is determined based on a historical review of the literature. Furthermore, following a careful comparison with all species that inhabit the southern austral forest, and that could potentially correspond to Zachaenus roseus, we conclude that this taxon is placed in the synonym of Eupsophus calcaratus (Günther, 1881).Fil: Lavilla, Esteban Orlando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Fundación Miguel Lillo; ArgentinaFil: Nuñez, J. J.. Universidad Austral de Chile; ChileFil: Rabanal, F. E.. Universidad Austral de Chhile; ChileFil: Langone, José A.. Museo Nacional de Historia Natural; UruguayFil: de Sá, Rafael O.. University of Richmon; Estados Unido

Polarized X-ray-emission Studies of Methyl Chloride and the Chlorofluoromethanes

A new technique sensitive to molecular orientation and geometry, and based on measuring the polarization of x-ray emission, has been applied to the Cl-containing molecules methyl chloride (CH3Cl) and the chlorofluoromethanes (CF3Cl, CF2Cl2, and CFCl3) in the gas phase. Upon selective excitation using monochromatic synchrotron radiation in the Cl K-edge (Cl 1s) near-threshold region, polarization-selective x-ray emission studies reveal highly polarized molecular valence x-ray fluorescence for all four molecules. The degree and the orientation of the polarized emission are observed to be sensitive to the incident excitation energy near the Cl Kedge. In some cases, the polarization direction for x-ray emission reverses for small changes in incident excitation energy (a few eV). It is shown that the polarized x-ray emission technique can be used to infer, directly from experiment, symmetries of occupied and unoccupied valence molecular orbitals, an- isotropies in absorption and emission, and orientational and geometrical information. It is suggested that the x-ray polarized-fluorescence phenomenon, reported here for simple molecules, can be used as a new approach to study more complicated systems in a variety of environments