3,731 research outputs found

    Aplicação de estudos genéticos para uso e conservação de uma espécie tropical em risco de extinção: o pau-rosa (Aniba rosaeodora).

    Get PDF
    Esta pesquisa tem como objetivos avaliar a variabilidade genética existente entre e dentro de populações naturais através do uso de isoenzimas e estabelecer protocolo de micropropagação de Aniba rosaedora; para gerar subsídios na elaboração de estratégias de conservação e alternativas para a utilização racional da espécie.bitstream/item/89195/1/PA-12-Regina-Quinzen.pd

    On Dwass' method for deriving the distribution of rank order statistics

    Get PDF
    summary:This note presents a critical examination of Dwass' method for obtaining the distribution of rank order statistics defined on random samples obtained from the same continuous population. New situations are discussed for the usefulness of the method

    High sensitivity and multifunctional micro-Hall sensors fabricated using InAlSb/InAsSb/InAlSb heterostructures

    Get PDF
    Further diversification of Hall sensor technology requires development of materials with high electron mobility and an ultrathin conducting layer very close to the material's surface. Here, we describe the magnetoresistive properties of micro-Hall devices fabricated using InAlSb/InAsSb/InAlSb heterostructures where electrical conduction was confined to a 30 nm-InAsSb two-dimensional electron gas layer. The 300 K electron mobility and sheet carrier concentration were 36 500 cm(2) V-1 s(-1) and 2.5 x 10(11) cm(-2), respectively. The maximum current-related sensitivity was 2 750 V A(-1) T-1, which was about an order of magnitude greater than AlGaAs/InGaAs pseudomorphic heterostructures devices. Photolithography was used to fabricate 1 mu m x 1 mu m Hall probes, which were installed into a scanning Hall probe microscope and used to image the surface of a hard disk

    Demography of helminth parasites in relation to biometic characteristics of Mastacembalus armatus

    Get PDF
    The study was conducted to collect and identify helminth parasites of Mastacembalus armatus and also to determine the prevalence intensity and abundance of parasitic infection. 118 M. armatus, obtained from different sampling stations of Yamuna river between March 2008 to February 2009 were examined for endoparasitic helminth infections. Of these only 31 fishes were found infected. Four helminth species including one nematode (Ascaridia ganpatii), two cestodes (Polyonchobothrium armatii, Senga nayari) and one trematode (Eucreadium pandeyi)were found in host fish. The over all monthly infestation of prevalence (0.29), intensity (3.28) and abundance (1.13) were recorded. The maximum infection was recorded in middle size range while very small and larger fishes showed lesser susceptibility to helminth parasites

    Histopathological analysis of liver in Puntius ticto exposed to water soluble fraction (WSF) of petrol

    Get PDF
    The fresh water fish Puntius ticto were exposed to lethal concentration of water soluble fraction (WSF) of petrol (5%-PF1, 10%-PF2, 15%-PF3, 20%-PF4 and 25%-PF5) for 96 hours. The exposure of WSF produced some conspicuous histopathological changes in liver. The swelling of hepatocytes, degeneration, necrosis, hemolysis, dilation, congestion and fibrosis in blood sinusoids were the prominent changes observed. The histological analysis showed increasing damages dose-dependents and time-dependents
    corecore