391 research outputs found

    Mapping plant area index of tropical forest by Lidar: calibrating ALS with TLS

    Get PDF
    SilviLaser 2015, La Grande Motte, FRA, 28-/09/2015 - 30/09/2015International audienceHighlights: - We compare Plant Area Density (PAD) profiles derived from Terrestrial Laser Scanning (TLS) and contemporaneous Aerial Laser Scanning (ALS) in dense tropical forest- Poor sampling of the lower part of the canopy profile by ALS is mitigated by using a multiple resolution approach- Anisotropy of transmittance revealed by TLS allows further improvement of PAD estimates

    Genes

    Get PDF
    O livro traz uma análise sobre a fronteira entre ciência e tecnologia, focalizando as novas idéias da era pós-genômica. Com uma linguagem clara e compreensível, o autor analisa os avanços científicos e suas conseqüências para a humanidade, com foco no desenvolvimento da biologia molecular e da genética

    Nutrient solution for mint production in hydroponic solution

    Get PDF
    A menta (Mentha arvensis L.) é uma planta aromática e que produz um óleo essencial rico em mentol. Para o cultivo hidropônico de hortaliças folhosas e de frutos existe um grande número de soluções nutritivas recomendadas pela pesquisa; no entanto, existem poucas informações sobre soluções nutritivas para menta. O objetivo deste trabalho foi avaliar uma solução nutritiva para o cultivo de menta em hidroponia. Conduziram-se dois experimentos de outubro a dezembro de 2004 em Santa Maria, RS. Para o experimento a campo, as mudas foram obtidas por estacas e produzidas em substrato organo-mineral (plantmax®), posteriormente transplantadas para canteiros de 5,00 m de comprimento e 1,00 de largura, no espaçamento 0,60 x 0,30 m. No sistema hidropônico "NFT", as mudas foram propagadas por estaquia em espuma fenólica, onde permaceram 18 dias no berçário, quando foram transferidas para as bancadas de produção final. O delineamento experimental foi blocos ao acaso em esquema fatorial 2x2 com os fatores: concentração da solução nutritiva e espaçamentos. Determinou-se a fitomassa seca, o teor de óleo essencial e o mentol. Os melhores resultados de teor de óleo essencial (0,60 ml 100 g-1 de folhas frescas), mentol (82,4%) e fitomassa seca (45 g planta-1) foram obtidos com 100% da concentração da solução nutritiva no transplante e reposição de 50% quando a condutividade elétrica reduziu 50% do valor inicial e no espaçamento de 0,50 m x 0,25 m nos canais de cultivo. Constatou-se que o teor e rendimento de óleo essencial e fitomassa seca no cultivo hidropônico com a solução nutritiva proposta foram superiores aos encontrados em cultivo a campo de 27 g planta-1de fitomassa seca, 0,53 Ml 100 g-1 de folhas frescas de óleo essencial e 64,43% de mentol. A solução nutritiva com concentração de 100% no transplante e reposição de 50% dos nutrientes quando a condutividade elétrica reduzir 50% do valor inicial e o espaçamento 0,50 x 0,25 m pode ser recomendada para o cultivo hidropônico de Mentha arvensis.The mint (Mentha arvensis L.) is an aromatic plant that produces essential oil with high menthol concentration. For the hydroponic cultivation of vegetables and fruits, a great number of recommended formulas exist; however, little information exists about hydroponic solutions for mint. The goal of this work was to evaluate a nutrient solution for the mint cultivation in hydroponic system. Two experiments were carried out from October to December, 2004. For the field experiment, transplants were obtained from cuttings and produced in organic mineral substrates (plantmax®). Later they were transplanted in seed beds of 5.00 m length and 1.00 m width, spacings of 0.60 x 0.30 m. For the hydroponic system NFT, seedlings were obtained from cuttings and planted in phenolic foam where they stayed during 18 days. After that, they were transplanted to a production canal. The experimental design was a 2x2 factorial (nutrient solution concentrations x spacings). The hydroponic solution with 100% concentration in transplant and 50% replacement when the electric condutivity decreased 50% of the initial value and 0.5 x 0.25 m spacings resulted in the highest concentration of essential oil (0.60 mL 100 g-1 fresh leaves), menthol (82,4%) and total dry matter (45 g plant-1). In hydroponic system the yield of dry matter and content of essential oil was higher than under soil conditions 27 g planta-1 of dry matter, concentration oil 0.53 mL 100 g-1 and 64,43% of menthol. The hydroponic solution with 100% concentration in transplant and 50% replacement when the electric condutivity decreased 50% of the initial value and 0.5 x 0.25 m spacing can be recommended for the cultivation of mint in hydroponic solution

    Terahertz wave generation via optical rectification from multiferroic BiFeO3

    Full text link
    We detected broadband coherent terahertz (THz) emission from multiferroic BiFeO3 after illuminating a high-quality bulk single ferroelectric domain crystal with a ~100 fs optical pulse. The dependence of the emitted THz waveform on the energy and polarization of the optical pulse is consistent with the optical rectification mechanism of THz emission. The THz emission provides a sensitive probe of the electric polarization state of BiFeO3, enabling applications in ferroelectric memories and ferroelectric domain imaging. We also report room-temperature THz optical constants of BiFeO3.Comment: accepted for publication in Applied Physics Letter

    Low energy LIDARs for biomass applications

    Get PDF
    SilviLaser 2015, La Grande Motte, FRA, 28-/09/2015 - 30/09/2015International audienceA new approach for LIDAR altimetry mission for biomass applications ( tree height measurement ) is explored based on low emitted laser energy at high repetition fr equency. Low energy approach drastical ly reduces the laser induced risks. Altimetry performances meet preliminary science requirements . The proposed instrument design is compatible with a space mission

    Modelling full waveform Lidar data on forest structures at plot level : a sensitivity analysis of forest and sensor main characteristics on full-waveform simulated data

    Get PDF
    [Departement_IRSTEA]Territoires [TR1_IRSTEA]SYNERGIE [Axe_IRSTEA]TETIS-ATTOSSilviLaser, La Grande Motte, FRA, 28-/09/2015 - 30/09/2015International audienceA new approach for LIDAR altimetry mission for biomass applications (tree height measurement) is explored based on low emitted laser energy at high repetition frequency. Low energy approach drastical ly reduces the laser induced risks. Altimetry performances meet preliminary science requirements . The proposed instrument design is compatible with a space mission

    Trypanosoma rangeli: a new perspective for studying the modulation of immune reactions of Rhodnius prolixus

    Get PDF
    Insects are exposed to a wide range of microorganisms (bacteria, fungi, parasites and viruses) and have interconnected powerful immune reactions. Although insects lack an acquired immune system they have well-developed innate immune defences that allow a general and rapid response to infectious agents

    DODAB/Monoolein mixed cationic liposomes for gene delivery : investigation by DLS, DSC, fluorescence spectroscopy and phase scanning microscopy

    Get PDF
    FCT and FEDER for financial support to CFUM and also by funding through project PTDC/QUI/69795/2006 and PhD grant of J.P.N. Silva (SFRH/BD/46968/2009)

    Vesicle-micelle transition in aqueous mixtures of the cationic dioctadecyldimethylammonium and octadecyltrimethylammonium bromide surfactants

    Get PDF
    The vesicle-micelle transition in aqueous mixtures of dioctadecyldimethylammonium and octadecyltrimethylammonium bromide (DODAB and C18TAB) cationic surfactants, having respectively double and single chain, was investigated by differential scanning calorimetry (DSC), steady state fluorescence, dynamic light scattering (DLS) and surface tension. The experiments performed at constant up to 1.0 mM total surfactant concentration reveal that these homologue surfactants mix together to form either mixed vesicles and/or micelles, or both of these structures in equilibrium, depending on the relative amount of the surfactants. The main transition melting temperature Tm of the mixed DODAB-C18TAB vesicles is larger than that for the neat DODAB in water owing to the incorporation of C18TAB in the vesicle bilayer, however, little amount of C18TAB having a minor effect on the Tm of DODAB. The surface tension decreases sigmoidally with C18TAB concentration and the inflection point lies around xDODAB ≈ 0.4, indicating the onset of micelle formation owing to saturation of DODAB vesicles by C18TAB molecules and formation of vesicle structures. At low C18TAB concentrations When xDODAB > 0.5 C18TAB molecules are mainly solubilized by the vesicles bilayers, while at high C18TAB concentrations but when xDODAB < 0.25 micelles are dominant. Fluorescence data of the Nile Red probe incorporated in the system at different surfactant molar fractions indicate the formation of micelle and vesicle structures. These structures have apparent hydrodynamic radius RH of about 180 and 500-800 nm, respectively, as obtained by DLS measurements.Fundação para a Ciência e a Tecnologia (FCT
    corecore