28 research outputs found

    Amphibian life history in a temperate environment of the Mexican Plateau: dimorphism, phenology and trophic ecology of a hylid frog, Hyla eximia (=Dryophytes eximius)

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    The study of demographic and life history aspects of an organism provides valuable information for its conservation. Here, we analyze the phenology of the Mountain Treefrog Hyla eximia (= Dryophytes eximius) in a temperate environment of the Mexican Plateau. Females were larger in snout-vent length and body mass than males. The peak period of activity occurred in the rainy season (May–September), with amplexus and egg deposition occurring between June and July, and larval development from July to August. A logistic model best explained observed male growth patterns, while the Von Bertalanffy model better described female growth. Notably, males grew faster than females, although females reached a larger overall body size. The diet of this species is made up of 10 prey categories. The index of diet importance indicated that males feed mainly on Coleoptera and Diptera, while females feed on Coleoptera, Diptera, Hemiptera, and Aranea. Both females and males showed a significant abundance of plant material in their stomachs, suggesting that H. eximia might exhibit highly specialized feeding behavior. Reproduction was seasonal, and both female and male reproductive cycles are synchronized with the rainy season. These natural history characteristics provide information to better understand their responses to environmental conditions

    The Effects of Interactions on the Structure and Morphology of Elliptical/Lenticular galaxies in Pairs

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    We present a photometric and structural analysis of 42 E/S0 galaxies in (E/S0 + S) pairs observed in the BVRI color bands. We empirically determine the effects of interactions on their morphology, structure and stellar populations as seen from the light concentration (C), asymmetry (A), and clumpiness (S) parameters. We further compare these values to a control sample of 67 mostly isolated, non-interacting E/S0 galaxies. The paired E/S0 galaxies occupy a more scattered loci in CAS space than non-interacting E/S0's, and the structural effects of interactions on E/S0's are minor, in contrast to disk galaxies involved in interactions. This suggests that observational methods for recognizing interactions at high z, such the CAS methodology, would hardly detect E/S0's involved in interactions (related to early phases of the so called `dry-mergers'). We however find statistical differences in A when comparing isolated and interacting E/S0s. In the mean, paired E/S0 galaxies have A values 2.96+-0.72 times larger than the ones of non-interacting E/S0's. For the subset of presumably strongly interacting E/S0's, A and S can be several times larger than the typical values of the isolated E/S0's. We show that the asymmetries are consistent with several internal and external morphological distortions. We conclude that the interacting E/S0s in pairs should be dense, gas poor galaxies in systems spaning a wide range of interaction stages, with typical merging timescales >~ 0.1-0.5 Gyr. We use the observed phenomenology of these galaxies to predict the approximate loci of `dry pre-mergers' in the CAS space.(Abridged)Comment: 23 pages, 9 figures included. To appear in The Astronomical Journa

    Shrike predation on the lizard Mesalina adramitana in Qatar; a review of reported reptile and amphibian prey

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    We report, for the first time, evidence of predation by a shrike (Lanius sp.) on the lizard Mesalina adramitana. This is the first record of predation by shrikes on lizards in Qatar. Whilst we did not directly observe the event, the presence of shrikes in the area and the method of impalement indicate shrikes as the predator. The lizard was found freshly impaled on a palm tree (Phoenix dactylifera), at 150 cm above ground. Bird species of the genus Lanius are well-known predators of lizards, and in arid environments reptiles are likely common prey for these birds. We provide a review of literature concerning predatory events by shrikes on reptiles and amphibians. We suggest inspection of shrubs for animals impaled by shrikes can improve biodiversity inventories, complementing other commonly used methods

    Nanocomposites from spent coffee grounds and iron/zinc oxide: green synthesis, characterization, and application in textile wastewater treatment

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    This study reports on a novel composite of bimetallic FeO/ZnO nanoparticles supported by spent coffee grounds (SCGs). The leaves of eucalyptus (Eucalyptus globulus Labill) and trumpet (Cuphea aequipetala Cav), with their high antioxidant content, serve as bio-reductant agents for the green synthesis of nanoparticles. It was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Stable nanoparticles were produced with different diameters of 5–30 nm, and they were applied as catalysts in Fenton-like processes. Box–Behnken experimental design (BBD) was used to determine the optimal removal efficiency with three factors and was used in the degradation of textile dyes from wastewater. The nanocomposite displayed a high decolorization ratio (88%) of indigo carmine in the presence of H2O2 combined. This resulted in a reduction in chemical oxygen demand (COD) of 56% at 120 min of contact time at an initial pH of 3.0 and a 0.5 g/L of catalyst dose, a H2O2 concentration of 8.8 mM/L, an initial dye concentration of 100 mg/L, and a temperature of 25 °C. HIGHLIGHTS Green synthesis of FeO/ZnO NPs using eucalyptus (Eucalyptus globulus Labill) and trumpet (Cuphea aequipetala Cav) extract was done.; The process was optimized using a Box–Behnken design.; UV–Visible spectroscopy, SEM, XRD, and TEM were done to analyze the structure morphology, size, and shape of nanoparticles.; Nanocomposite of bimetallic FeO/ZnO was used for the removal of indigo carmine supported by spent coffee grounds (SCGs).

    Evaluation of the efficiency of water treatment by a solar heating and distillation system

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    Presently, many industries discharge colored wastewater without any treatment to water bodies such as rivers and lakes affecting flora and fauna. Due to its chemical composition, its self-purification in phreatic bodies is complicated. Although there are chemical, physical and biological treatments dedicated to the degradation of this type of compounds, they present economic and energetic disadvantages. This study reports the use of solar energy for the treatment of water containing carmine red dye at 25 ppm. The system consists of the coupling of two modules; the first heats wastewater using a parabolic heater, while the second separates clean water (distilled) from pollutants. It was observed that when a galvanized ZnO plate is introduced into the distillation unit a photodegradation process takes place improving the characteristic of the concentrate. Optimal conditions allow an efficiency of 87 % in the production of the distilled water obtained. Parameters such as pH, Conductivity, COD, Turbidity and Total Solids, indicate that the distilled water complies with the maximum permissible limits for water quality established in Mexican regulations. A 93 % photodegradation of carmine red dye wastewater was detected within 120 min during the process, which was verified by UV-Vis and IR characterization
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