267 research outputs found

    Atributos anatômicos de lâminas foliares de Paspalum spp.

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    Gramíneas do gênero Paspalum spp. apresentam alto potencial para o melhoramento genético, devido à sua grande variabilidade genética. Este estudo, conduzido na Universidade Federal da Grande Dourados, teve como objetivo avaliar atributos anatômicos de lâminas foliares de Paspalum spp. (P. malacophyllum - P30, P. guenoarum - P65, P. glaucescens - P114, P. spp.- Pl16, P. spp. - P127, P. guenoarum - P148, P. regnellii - P191 e uma cultivar comercial- P. alralum cv. Pojuca). Utilizou-se o delineamento de blocos ao acaso, oito genótipos e quatro repetições. Os fragmentos das lâminas foram fixados em F AA e após efetuou-se o preparo histológico. Alta variabilidade entre os genótipos foi observada quanto à proporção e arranjo de tecidos, e presença de tanino condensado na epiderme. Dos caracteres avaliados a presença de estrutura girder, foi a que mais discriminou os genótipos quanto ao potencial qualitativo das lâminas. Estudos devem ser conduzidos para verificar o efeito do tanino condensado, presente na epiderme, no potencial qualitativo dos genótipos

    Depletion-induced seismicity in NW-Germany: lessons from comprehensive investigations

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    Evaluating various investigations for north-German gas fields, we discuss past and actual evolutions of the rock fabric in the light of dilatant driven and spontaneous contractant critical phenomena. Features of the latter were discovered by multi-stage triaxial tests with water-saturated sandstone samples and were similarly observed around the gas fields. A Mohr–Coulomb condition with quasi-local stress components (σ^2˘71{\hat{\sigma }}\u27_1 and σ^2˘73{\hat{\sigma }}\u27_3), and variable parameters ϕ’ and c^2˘7{{\hat{c}}}\u27, can capture successive critical states of the solid fabric. The implied driven dilatation up to a collapse with contraction is captured by a stress-dilatancy relation. Fractal patterns of shear bands (faults) dominate if the smallest principal stress σ^2˘73{\hat{\sigma }}\u27_3 exceeds c^2˘7{{\hat{c}}}\u27, otherwise cracks dominate and can lead to a rockburst. Triaxial tests with X-ray attenuation, seismometry including the splitting of shear waves and/or neutron beam diffraction contribute to clarification and validation. Seismic early warning and calculation models for various geotechnical operations with dominating faults can thus be improved, but the task is more difficult for rockbursts

    Interpolating d-r.e. and REA degrees between r.e. degrees

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    We provide three new results about interpolating 2-r.e. (i.e. d-r.e.) or 2-REA (recursively enumerable in and above) degrees between given r.e. degrees: Proposition 1.13. If c < h are r.e., c is low and h is high, then there is an a < h which is REA in c but not r.e. Theorem 2.1. For all high r.e. degrees h < g there is a properly d-r.e. degree a such that h < a < g and a is r.e. in h. Theorem 3.1. There is an incomplete nonrecursive r.e. A such that every set REA in A and recursive in 0′ is of r.e. degree. The first proof is a variation on the construction of Soare and Stob (1982). The second combines highness with a modified version of the proof strategy of Cooper et al. (1989). The third theorem is a rather surprising result with a somewhat unusual proof strategy. Its proof is a 0‴ argument that at times moves left in the tree so that the accessible nodes are not linearly ordered at each stage. Thus the construction lacks a true path in the usual sense. Two substitute notions fill this role: The true nodes are the leftmost ones accessible infinitely often; the semitrue nodes are the leftmost ones such that there are infinitely many stages at which some extension is accessible. Another unusual feature of the construction is that it involves using distinct priority orderings to control the interactions of different parts of the construction

    Physical Impediment Towards Digestive Breakdown in Leaf Blades of Brachiaria Brizantha

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    Consumption of grasses is influenced by the physical properties of forages which confer resistance to digestive breakdown. Such barriers may be the proportion of indigestible tissues, girder structure and epidermal cell arrangements. Anatomical factors, if identified early are invaluable tools in breeding and selection programmes for forages of high quality. The objective of this study was to verify which anatomical attributes might be interfering in the physical resistance to rumen breakdown in Brachiaria brizantha ecotypes

    Nondensity of double bubbles in the D.C.E. degrees

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    © Springer International Publishing AG 2017.In this paper, we show that the so-called “double bubbles” are not downward dense in the d.c.e. degrees. Here, a pair of d.c.e. degrees d1 > d2 > 0 forms a double bubble if all d.c.e. degrees below d1 are comparable with d2

    Pathological findings in the red fox (Vulpes vulpes), stone marten (Martes foina) and raccoon dog (Nyctereutes procyonoides), with special emphasis on infectious and zoonotic agents in Northern Germany

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    Anthropogenic landscape changes contributed to the reduction of availability of habitats to wild animals. Hence, the presence of wild terrestrial carnivores in urban and peri-urban sites has increased considerably over the years implying an increased risk of interspecies spillover of infectious diseases and the transmission of zoonoses. The present study provides a detailed characterisation of the health status of the red fox (Vulpes vulpes), stone marten (Martes foina) and raccoon dog (Nyctereutes procyonoides) in their natural rural and periurban habitats in Schleswig-Holstein, Germany between November 2013 and January 2016 with focus on zoonoses and infectious diseases that are potentially threatening to other wildlife or domestic animal species. 79 red foxes, 17 stone martens and 10 raccoon dogs were collected from traps or hunts. In order to detect morphological changes and potential infectious diseases, necropsy and pathohistological work-up was performed. Additionally, in selected animals immunohistochemistry (influenza A virus, parvovirus, feline leukemia virus, Borna disease virus, tick-borne encephalitis, canine adenovirus, Neospora caninum, Toxoplasma gondii and Listeria monocytogenes), next-generation sequencing, polymerase chain reaction (fox circovirus) and serum-neutralisation analysis (canine distemper virus) were performed. Furthermore, all animals were screened for fox rabies virus (immunofluorescence), canine distemper virus (immunohistochemistry) and Aujeszky's disease (virus cultivation). The most important findings included encephalitis (n = 16) and pneumonia (n =20). None of the investigations revealed a specific cause for the observed morphological alterations except for one animal with an elevated serum titer of 1:160 for canine distemper. Animals displayed macroscopically and/or histopathologically detectable infections with parasites, including Taenia sp., Toxocara sp. and Alaria alata. In summary, wildlife predators carry zoonotic parasitic disease and suffer from inflammatory diseases of yet unknown etiology, possibly bearing infectious potential for other animal species and humans. This study highlights the value of monitoring terrestrial wildlife following the "One Health" notion, to estimate the incidence and the possible spread of zoonotic pathogens and to avoid animal to animal spillover as well as transmission to humans
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