438 research outputs found
Herpetofauna of the Little South Fork Basin (Cumberland River Drainage), Wayne and McCreary Counties, Kentucky
Author Institution: Department of Zoology, Southern Illinois UniversityAmphibians and reptiles were surveyed along Little South Fork (tributary of the Cumberland River) and other sites within the drainage basin from May-October 1996 and April-May 1997 to determine the distribution and composition of the herpetofauna. Twenty-three species of amphibians and reptiles were captured or observed. Based on published and unpublished accounts and museum records, 41 species of amphibians and reptiles are known from the basin in Wayne and McCreary counties. Chelydra serpentina and Sternotherus odoratus are known from Little South Fork, and the latter from Wayne County, for the first time. Graptemys geographica was distributed throughout the surveyed portion of Little South Fork. Leeches (Placob delta parasitical were found on two Graptemys geographica and one Chelydra serpentina
Argulus Ambystoma, a New Species Parasitic on the Salamander Ambystoma Dumerilii from Mexico (Crustacea: Branchiura: Argulidae)
Author Institution: Department of Zoology, Southern Illinois UniversityA new species of Argulus is described based on 18 specimens taken from the salamander (achoque or ajolote) Ambystoma dumerilii Duges, collected in Lake Patzcuaro, Michoacan, Mexico. Diagnostic characters include the shape of the respiratory areas, number of sclerites in suction cup rods, and structures on the legs of males. Females are heavily stippled, whereas males have a very distinctive pigment pattern consisting of abundant melanophores covering the testes dors ally and two dark, inverted triangular patches on the carapace dorsally. The new species is similar to the North American species, A versicolor,A. americanus, A. maculosus, and A diversus. A single, dorsal pore was observed on each caudal ramus using scanning electron microscopy; these pores have not been reported previously in the Branchiura
Argulus yucatanus N. Sp. (Crustacea: Branchiura) Parasitic on Cichlasoma urophthalmus from Yucatan, Mexico
A new species, Argulus yucatanus, is described based on 14 specimens from Cichlasoma urophthalmus collected in Celestun Lagoon, Yucatan, Mexico. Diagnostic characters include the number of and shape of sclerites in the suction cup support rods, shape of and position of respiratory areas, and modifications on the legs of males. In males, the coxae of the 2nd legs bear an angular lobe with 5–7 erect scales and 13–21 sensilla. The new species is compared to Argulus funduli Krøyer, 1863, A. chromidis Krøyer, 1863, A. cubensis Wilson, 1936, A. rhamdiae Wilson, 1936, and A. varians Bere, 1936
KP line solitons and Tamari lattices
The KP-II equation possesses a class of line soliton solutions which can be
qualitatively described via a tropical approximation as a chain of rooted
binary trees, except at "critical" events where a transition to a different
rooted binary tree takes place. We prove that these correspond to maximal
chains in Tamari lattices (which are poset structures on associahedra). We
further derive results that allow to compute details of the evolution,
including the critical events. Moreover, we present some insights into the
structure of the more general line soliton solutions. All this yields a
characterization of possible evolutions of line soliton patterns on a shallow
fluid surface (provided that the KP-II approximation applies).Comment: 49 pages, 36 figures, second version: section 4 expande
Describing and simulating concurrent quantum systems
We present a programming language for describing and analysing concurrent quantum systems. We have an interpreter for programs in the language, using a symbolic rather than a numeric calculator, and we give its performance on examples from quantum communication and cryptography
Selection of diazotrophic bacterial communities in biological sand filter mesocosms used for the treatment of phenolic-laden wastewater
Agri effluents such as winery or olive mill waste-waters are characterized by high phenolic concentrations. These compounds are highly toxic and generally refractory to biodegradation. Biological sand filters (BSFs) represent inexpensive, environmentally friendly, and sustainable wastewater treatment systems which rely vastly on microbial catabolic processes. Using denaturing gradient gel electrophoresis and terminal-restriction fragment length polymorphism, this study aimed to assess the impact of increasing concentrations of synthetic phenolic-rich wastewater, ranging from 96 mg L−1 gallic acid and138 mg L−1 vanillin (i.e., a total chemical oxygen demand (COD) of 234 mg L−1) to 2,400mg L−1 gallic acid and 3,442 mg L−1 vanillin (5,842 mg COD L−1), on bacterialcommunities and the specific functional diazotrophic community from BSF mesocosms. This amendment procedure instigated efficient BSF phenolic removal, significant modifications of the bacterial communities, and notably led to the selection of a phenolic-resistant and less diverse diazotrophic community. This suggests that bioavailable N is crucial in the functioning of biological treatment processes involving microbial communities, and thus that functional alterations in the bacterial communities in BSFs ensure provision of sufficient bioavailable nitrogen for the degradation of wastewater with a high C/N ratio.Web of Scienc
Impacts of organic and conventional crop management on diversity and activity of free-living nitrogen fixing bacteria and total bacteria are subsidiary to temporal effects
A three year field study (2007-2009) of the diversity and numbers of the total and metabolically active free-living diazotophic bacteria and total bacterial communities in organic and conventionally managed agricultural soil was conducted at the Nafferton Factorial Systems Comparison (NFSC) study, in northeast England. The result demonstrated that there was no consistent effect of either organic or conventional soil management across the three years on the diversity or quantity of either diazotrophic or total bacterial communities. However, ordination analyses carried out on data from each individual year showed that factors associated with the different fertility management measures including availability of nitrogen species, organic carbon and pH, did exert significant effects on the structure of both diazotrophic and total bacterial communities. It appeared that the dominant drivers of qualitative and quantitative changes in both communities were annual and seasonal effects. Moreover, regression analyses showed activity of both communities was significantly affected by soil temperature and climatic conditions. The diazotrophic community showed no significant change in diversity across the three years, however, the total bacterial community significantly increased in diversity year on year. Diversity was always greatest during March for both diazotrophic and total bacterial communities. Quantitative analyses using qPCR of each community indicated that metabolically active diazotrophs were highest in year 1 but the population significantly declined in year 2 before recovering somewhat in the final year. The total bacterial population in contrast increased significantly each year. Seasonal effects were less consistent in this quantitative study
L'incidence des variations d'intervalle de vêlage sur la productivité de la vache laitière
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