49 resultados para 12034
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A mass in the pelvic canal of a 4-year-old pregnant alpaca hembra diagnosed as leiomyosarcoma of the urogenital tract was confirmed by biopsy. Following a tube cystotomy, the alpaca was presented 33 d later, 2 d after the tube cystotomy had been dislodged. A dead cria was delivered by caesarean section.
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Agricultural intensification has caused a decline in structural elements in European farmland, where natural habitats are increasingly fragmented. The loss of habitat structures has a detrimental effect on biodiversity and affects bat species that depend on vegetation structures for foraging and commuting. We investigated the impact of connectivity and configuration of structural landscape elements on flight activity, species richness and diversity of insectivorous bats and distinguished three bat guilds according to species-specific bioacoustic characteristics. We tested whether bats with shorter-range echolocation were more sensitive to habitat fragmentation than bats with longer-range echolocation. We expected to find different connectivity thresholds for the three guilds and hypothesized that bats prefer linear over patchy landscape elements. Bat activity was quantified using repeated acoustic monitoring in 225 locations at 15 study plots distributed across the Swiss Central Plateau, where connectivity and the shape of landscape elements were determined by spatial analysis (GIS). Spectrograms of bat calls were assigned to species with the software batit by means of image recognition and statistical classification algorithms. Bat activity was significantly higher around landscape elements compared to open control areas. Short- and long-range echolocating bats were more active in well-connected landscapes, but optimal connectivity levels differed between the guilds. Species richness increased significantly with connectivity, while species diversity did not (Shannon's diversity index). Total bat activity was unaffected by the shape of landscape elements. Synthesis and applications. This study highlights the importance of connectivity in farmland landscapes for bats, with shorter-range echolocating bats being particularly sensitive to habitat fragmentation. More structurally diverse landscape elements are likely to reduce population declines of bats and could improve conditions for other declining species, including birds. Activity was highest around optimal values of connectivity, which must be evaluated for the different guilds and spatially targeted for a region's habitat configuration. In a multi-species approach, we recommend the reintroduction of structural elements to increase habitat heterogeneity should become part of agri-environment schemes.
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The multiple high-pressure (HP), low-temperature (LT) metamorphic units of Western and Central Anatolia offer a great opportunity to investigate the subduction- and continental accretion-related evolution of the eastern limb of the long-lived Aegean subduction system. Recent reports of the HP–LT index mineral Fe-Mg-carpholite in three metasedimentary units of the Gondwana-derived Anatolide–Tauride continental block (namely the Afyon Zone, the Ören Unit and the southern Menderes Massif) suggest a more complicated scenario than the single-continental accretion model generally put forward in previous studies. This study presents the first isotopic dates (white mica 40Ar–39Ar geochronology), and where possible are combined with P–T estimates (chlorite thermometry, phengite barometry, multi-equilibrium thermobarometry), on carpholite-bearing rocks from these three HP–LT metasedimentary units. It is shown that, in the Afyon Zone, carpholite-bearing assemblages were retrogressed through greenschist-facies conditions at c. 67–62 Ma. Early retrograde stages in the Ören Unit are dated to 63–59 Ma. In the Kurudere–Nebiler Unit (HP Mesozoic cover of the southern Menderes Massif), HP retrograde stages are dated to c. 45 Ma, and post-collisional cooling to c. 26 Ma. These new results support that the Ören Unit represents the westernmost continuation of the Afyon Zone, whereas the Kurudere–Nebiler Unit correlates with the Cycladic Blueschist Unit of the Aegean Domain. In Western Anatolia, three successive HP–LT metamorphic belts thus formed: the northernmost Tavşanlı Zone (c. 88–82 Ma), the Ören–Afyon Zone (between 70 and 65 Ma), and the Kurudere–Nebiler Unit (c. 52–45 Ma). The southward younging trend of the HP–LT metamorphism from the upper and internal to the deeper and more external structural units, as in the Aegean Domain, points to the persistence of subduction in Western Anatolia between 93–90 and c. 35 Ma. After the accretion of the Menderes–Tauride terrane, in Eocene times, subduction stopped, leading to continental collision and associated Barrovian-type metamorphism. Because, by contrast, the Aegean subduction did remain active due to slab roll-back and trench migration, the eastern limb (below Southwestern Anatolia) of the Hellenic slab was dramatically curved and consequently teared. It therefore is suggested that the possibility for subduction to continue after the accretion of buoyant (e.g. continental) terranes probably depends much on palaeogeography.
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Debido al interés de empresas siderúrgicas de Mendoza (Argentina) de contar con adecuada provisión de madera para sus plantas industriales, en el Instituto Forestal de la Facultad de Ciencias Agrarias (UNCuyo) se produjeron plantas de Eucalyptus. sp. provenientes de semillas australianas y locales. Dichas plantas fueron llevadas a campo para evaluar su comportamiento en condiciones de cultivo bajo riego. El ensayo se realizó en Nueva California (Dpto. de San Martín, Mendoza), a 653 msnm, en suelos arenosos, profundos, sueltos, permeables y con poca capacidad de retención de agua. Se regó por aspersión con una lámina de 70 mm cada 10 días en verano y cada 20 en invierno. Las especies y procedencias ensayadas fueron: E. camaldulensis procedencias 15022, 15028, 15195, 15799 y local; E. badjensis procedencia 17127; E. intertexta procedencias 15095 y 15886; E. grandis procedencia 12081; E. fastigata procedencia 17126; E. johnstonii procedencia 15352; E. astringens procedencia 12842; E. amygdalina procedencia 12831; E. andrewsii ssp andrewsii procedencia 13037; E. regnans procedencia 12034; E. tereticornis procedencias 13301, 13304, 13309 y local; E. benthami procedencia 17347; E. sargentii procedencia 12406; E. viminalis procedencia 12884; E. globulus ssp. bicostata; E. sideroxylon de procedencia local; E. dalrympleana procedencias 13348 y 15273: E. cinerea procedencia 25 de Mayo (Buenos Aires) y E. leucoxylon de procedencia local. Se evaluó el comportamiento al primer año, expresado por el número de fallas producidas en cada 100 plantas. Las especies más promisorias fueron: E. camaldulensis procedencia 15022, E. camaldulensis procedencia 15799, E. camaldulensis procedencia 15195, E. tereticornis procedencia 13309 y E. camaldulensis de procedencia local, con menos del 30 % de fallas. Además, anualmente se tomaron los datos dasométricos de diámetro altura pecho (DAP) y altura total de cada una de las plantas. Al cuarto año, las especies más destacadas fueron: E. camaldulensis procedencias 15022, 15195 y local, todas ellas con diámetros entre 9 y 12 cm y alturas entre 7 y 9 m.
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This paper shows the development of a science-technological knowledge transfer model in Mexico, as a means to boost the limited relations between the scientific and industrial environments. The proposal is based on the analysis of eight organizations (research centers and firms) with varying degrees of skill in the practice of science-technological knowledge transfer, and carried out by the case study approach. The analysis highlights the synergistic use of the organizational and technological capabilities of each organization, as a means to identification of the knowledge transfer mechanisms best suited to enabling the establishment of cooperative processes, and achieve the R&D and innovation activities results.
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Mode of access: Internet.
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The work described in this thesis is directed towards the reduction of tyre/road interface noise and embodies a study of the factors involved in its generation. These factors comprise: (a) materials and construction of tyres and road surfaces (b) the spectral distribution of the noise. The importance of this work has become greater with reduction in engine noise. A review of the literature shows what has been achieved so far, and stresses the importance of maintaining other desirable tyre properties such as adhesion in wet conditions. The work has involved an analysis of mechanical factors in tyre construction and the behaviour of road surfaces. Measurements on noise have been carried out under practical conditions and also on replica surfaces in the laboratory, and in addition tests of wet road adhesion have been carried out with a variety of road surfaces. Consideration has been given to the psychological effects of the spectral distribution of noise. A major part of the work under-taken has been the development of a computer program, the results of which have made it possible to design a tyre tread block pattern to give an optimum spectral distribution. Sample tyres built to this design have been subjected to noise measurements and these have been shown to agree closely with the theoretical prediction and other properties of this tyre have proved to be satisfactory.