923 resultados para territorial range


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We describe a new species of Cycloramphus of the eleutherodactylus group from the Ilha dos Alcatrazes, southeastern Brazil, with descriptions of advertisement and territorial calls and notes on natural history. Additionally, we describe the advertisement and territorial calls of C. eleutherodactylus. The new species is diagnosed by the following set of characters: snout truncate in lateral and dorsal views; head wider than long; eyes protruding; tibia shorter than thigh; and distinct advertisement call. The new species is known from a single population on the Ilha dos Alcatrazes, a 149 ha island about 35 kin off São Paulo State coast where these frogs are scattered in a small valley. The very restricted range of the new species of Cycloramphus and the declining quality of its habitat qualify this frog as critically endangered.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Há uma grande lacuna no conhecimento da biologia e corologia de Nyctinomops aurispinosus. Nesta comunicação, nós apresentamos o registro mais austral deste molossídeo, realizado na cidade de Curitiba (25° 25' S e 49° 15' W, 920 m), estado do Paraná, Brasil, e sumarizamos a distribuição geográfica conhecida para a espécie na América do Sul.

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Quark-model descriptions of the nucleon-nucleon interaction contain two main ingredients, a quark-exchange mechanism for the short-range repulsion and meson exchanges for the medium- and long-range parts of the interaction. We point out the special role played by higher partial waves, and in particular the (1)F(3), as a very sensitive probe for the meson-exchange pan employed in these interaction models. In particular, we show that the presently available models fail to provide a reasonable description of higher partial waves and indicate the reasons for this shortcoming.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Since the mid 1980s the Atomic Force Microscope is one the most powerful tools to perform surface investigation, and since 1995 Non-Contact AFM achieved true atomic resolution. The Frequency-Modulated Atomic Force Microscope (FM-AFM) operates in the dynamic mode, which means that the control system of the FM-AFM must force the micro-cantilever to oscillate with constant amplitude and frequency. However, tip-sample interaction forces cause modulations in the microcantilever motion. A Phase-Locked loop (PLL) is used to demodulate the tip-sample interaction forces from the microcantilever motion. The demodulated signal is used as the feedback signal to the control system, and to generate both topographic and dissipation images. As a consequence, a proper design of the PLL is vital to the FM-AFM performance. In this work, using bifurcation analysis, the lock-in range of the PLL is determined as a function of the frequency shift (Q) of the microcantilever and of the other design parameters, providing a technique to properly design the PLL in the FM-AFM system. (C) 2011 Elsevier B.V. All rights reserved.

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This paper presents an analysis of pluviometric precipitation time series obtained from 45 data collection points, with daily rain measurements (in mm), from 45 counties within the nine climatic regions of the state of SA o pound Paulo, mostly for the period of 1950-1997. SA o pound Paulo State (Brazil) is situated between the inter-tropical climatic zone, dominated by tropical and equatorial masses, and the sub-tropical climatic zone controlled by tropical and polar air masses. Due to this location the State can be divided into three climatic zones: south-east and south-west, which are permanently humid, and north with a well defined dry period. Rescaled range analysis, or R/S analysis, has been used to investigate the scale properties of the time series. We found two clear values for the Hurst exponent, one for a period of 10 to 200 days (H(1)), and another for a period above 210 days (H(2)). The value of H(1) lies between 0.6 to 0.7 for all climatic zones indicating characteristics of persistence. However, H(2) is (i) close to 0.5 for the littoral area, showing random characteristics, (ii) close to 0.6 for mountain areas, indicating persistence characteristics, and (iii) close to 0.4 for the plane area, irrespective of whether the climate is dry or humid, and shows anti-persistence characteristics.

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Let f : M --> N be a continuous map between two closed n-manifolds such that f(*): H-*(M, Z(2)) --> H-* (N, Z(2)) is an isomorphism. Suppose that M immerses in Rn+k for 5 less than or equal to n < 2k. Then N also immerses in Rn+k. We use techniques of normal bordism theory to prove this result and we show that for a large family of spaces we can replace the homolog condition by the corresponding one in homotopy. (C) 2001 Elsevier B.V. B.V. All rights reserved.