Exigências de macronutrientes de dois cultivares de mandioca (Manihot esculenta Crantz)

This paper deals with the results of a field experiment conducted in order to study dry matter production and macronutrient accumulation in two cassava cultivars 'Branca de Santa Catarina' and 'IAC Mantiqueira'. Plants received an uniform dressing of N, P2O5 and K2O of 40, 80 and 60 kg/ha, respectively as ammonium sulphate, simple superphosphate, and muriate of potassium; N was top dressed 60 days after emergence. Two irrigations were provided in the beginning of the growth cycle. Plants were sampled and analysed for growth parameters and macronutrient composition in six occasions with 60 day intervals: The main conclusions and relevant data were as follows: 1. there was a statistical difference in root production of the two cultivars;.maximum dry matter accumulation took place in the period pf 120 - 180 days after emergence; 2. extraction of macronutrients was the same in the two cultivars, except for P; export was different only in the case of K and S.As exigências de N, P, K, Ca, Mg e S dos cultivares de mandioca (Branca de Santa Catarina e IAC Mantiqueira) foram avaliadas através da análise de material colhido em ensaio de campo. Verificou-se diferença apenas quanto à quantidade de P ex traído e K e S exportado (raízes)

Absorption of nutrients by grapevine under field conditions

From a well fertilized 7 years-old vineyard var. 'Niagara Rosada' (Vinis labrusca L. X Vitis vinifera L.). situated on an Entisol at country of Jundiaí, SP, Brazil, plants were harvested every fifteen days up to 150 days. The plants were divided into: terminal and basal leaves, terminal and basal shoots, and canes, as well grapes. The plant material was analysed by conventional methods for B, Cu, Fe, Mn and Zn. The research was conducted in order: a. to obtain data on the absorption and distribution of the nutrients by the grapevine; b. to obtain data on the exportation of nutrients by the shoots and by the grapes. Conclusions: The leaves present always a higher concentration in nutrients than the other parts of the plant. The leaves, shoots and grapes present different concentrations of the nutrients during the year. The maximum absorption by the leaves, shoots and grapes in mg per plant was observed at the following age (days): The grapevine exported by shoots (pruned) and by grapes the following quantities of nutrients in mg per plant: A vineyeard of 5,000 plants per hectare contains the following quantitites of nutrients: B = 145.45 g.; Cu = 33.60 g.; Fe = 588.85 g.; Mn = 4,093,35 g.; Za = 373.30 g.Ensaio foi conduzido com viderias da cultivar 'Niagara Rosada' (Vitis labrusca L. X Vitis vinifera L.) com 7 anos de idade, no município de Jundiaí, SP, (23°12' de latitude sul e 46°33' de longitude oeste e 715 m de altitude), situadas sobre um Regossolo unidade Currupira, com os objetivos de: (1) determinar as quantidades de nutrientes absorvidos pela videira nos diferentes estádios de desenvolvimento; (2) avaliar a exportação de nutrientes pela cultura durante um ciclo vegetativo. Após a brotação da videira, foram realizadas 17 coletas quinzenais de material. Foram coletadas e separadas as folhas das partes terminal e basal, sarmentos das partes terminal e basal e cachos. No material coletado foram determinados os teores de micronutrientes, com exceção do molibdênio e cloro. Curvas representativas das concentraçoes dos nutrientes nas partes da planta, em função da idade, foram obtidas a partir dos dados calculados através de equações de regressão. Pelos pontos de máximo estimaram-se as quantidades máximas de nutrientes extraídos. Concluiu-se que: - A concentração dos nutrientes é sempre maior nas folhas do que nos sarmentos e existem diferenças nas concentrações de nutrientes das folhas, sarmentos e cachos, em função da idade. - Os acúmulos máximos de nutrientes nas folhas, sarmentos e cachos ocorrem nas seguintes idades: - A exportação de nutrientes em mg por planta pelos cachos e sarmentos removidos pelas colheitas e poda é a seguinte

Acúmulo de nitrogênio, fósforo, potássio, cálcio, magnésio e enxofre pela videira (Vitis labrusca L. X Vitis vinifera L.) cv. 'Niágara rosada', durante um ciclo vegetativo

Plant material from a well fertilized 7 years-old vineyard var. 'Niagara Rosada' (Vitis labrusca L. X Vitis vinifera L.), situated on an Entisol at country of Jundiai, SP, Brazil, was harvested every fifteen days up to 150 days. The plants were divided into: terminal and basal leaves, terminal and basal shoots, and canes, as well grapes. The plant material was analysed by conventional methods for N, P, K, Ca, Mg, S. The research was conducted in order: a. to obtain information on the accumulation of dry matter, during a period of one year; b. to obtain data on the absorption and distribuition of the nutrients by the grapevine; c. to obtain data on the exportation of nutrients by the shoots and by the grapes. Conclusions : The maximum accumulation of the dry matter took place at the age of 148 days. The leaves present always a higher concentration in nutrients than the other parts of the plant. The leaves, shoots and grapes present different concentration of the nutrients during the year. The maximun absorption by the leaves, shoots and grapes in mg per plant was observed at the following age (days): The grapevine exported by shoots (pruned) and by grapes the following quantities of nutrients in mg per plant: A vineyeard of 5.000 plants per hectare content the following quantities of nutrients: N: 90.85 kg; P:28.40 kg; K: 97.60 kg; Ca: 41.20 kg; Mg: 8.10 kg; S: 9.30 kg.Ensaio foi conduzido com videiras de cultivar 'Niagara Rosada' (Vitis labrusca L. X Vitis vinifeva L.) com 7 anos de idade, no município de Jundiaí, SP (23°12' de latitude sul e 46º33' de longitude oeste e 715 m de altitude), situadas sobre um Regossolo unidade Currupira, com os objetivos de: (1) analisar o crescimento (produção de materia seca); (2) determinar as quantidades de nutrientes absorvidos pela videira nos diferentes estádios de desenvolvimento e (3) avaliar a exportação de nutrientes pela cultura durante o ciclo vegetativo. Após a brotação da videira, foram realizadas 17 coletas quinzenais de material. Foram coletadas e separadas as folhas das partes terminal e basal, sarmentos das partes terminal e basal e cachos. No material coletado foram determinados os teores de N, P, K, Ca, Mg e S. Curvas representativas dos acúmulos de matéria seca e das concentrações dos nutrientes nas partes da planta, em função da idade, foram obtidas a partir dos dados calculados através de equações de regressão. Pelos pontos de máximo estimaram-se a produção maxima de matéria seca e as quantidades de nutrientes extraídos. Conclui-se que: . A produção maxima de materia seca ocorre aos 148 dias. . A concentração dos nutrientes é sempre maior nas folhas do que nos sarmentos e existem diferenças nas concentrações de nutrientes das folhas, sarmentos e cachos, em função da idade. . Os acúmulos máximos de nutrientes nas folhas, sarmentos e cachos ocorrem nas seguintes idades

Aerosolized Amiloride for the Treatment of Lung Disease in Cystic Fibrosis

To the Editor: The April 26 issue of the Journal presented encouraging results by Knowles et al. regarding the beneficial effects of aerosolized amiloride in the treatment of cystic fibrosis.1 The introduction and discussion sections of this article described the function of amiloride as an inhibitor of sodium transport in the airway epithelium, and the authors suggested that the beneficial effects observed were exerted “at least in part by increasing the clearance of secretions.” Although the results of this investigation were promising in terms of the improvement in the decline of forced vital capacity in patients with cystic fibrosis, this

Black Hole Spin via Continuum Fitting and the Role of Spin in Powering Transient Jets

The spins of ten stellar black holes have been measured using the continuum-fitting method. These black holes are located in two distinct classes of X-ray binary systems, one that is persistently X-ray bright and another that is transient. Both the persistent and transient black holes remain for long periods in a state where their spectra are dominated by a thermal accretion disk component. The spin of a black hole of known mass and distance can be measured by fitting this thermal continuum spectrum to the thin-disk model of Novikov and Thorne; the key fit parameter is the radius of the inner edge of the black hole's accretion disk. Strong observational and theoretical evidence links the inner-disk radius to the radius of the innermost stable circular orbit, which is trivially related to the dimensionless spin parameter a_* of the black hole (|a_*| < 1). The ten spins that have so far been measured by this continuum-fitting method range widely from a_* \approx 0 to a_* > 0.95. The robustness of the method is demonstrated by the dozens or hundreds of independent and consistent measurements of spin that have been obtained for several black holes, and through careful consideration of many sources of systematic error. Among the results discussed is a dichotomy between the transient and persistent black holes; the latter have higher spins and larger masses. Also discussed is recently discovered evidence in the transient sources for a correlation between the power of ballistic jets and black hole spin.Comment: 30 pages. Accepted for publication in Space Science Reviews. Also to appear in hard cover in the Space Sciences Series of ISSI "The Physics of Accretion onto Black Holes" (Springer Publisher). Changes to Sections 5.2, 6.1 and 7.4. Section 7.4 responds to Russell et al. 2013 (MNRAS, 431, 405) who find no evidence for a correlation between the power of ballistic jets and black hole spi

D* Production in Deep Inelastic Scattering at HERA

This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel $D^{*+}\to (D^0 \to K^- \pi^+) \pi^+$ (+ c.c.) has been used in the study. The $e^+p$ cross section for inclusive D^{*\pm} production with $5<Q^2<100 GeV^2$ and $y<0.7$ is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {$1.3<p_T(D^{*\pm})<9.0$ GeV and $| \eta(D^{*\pm}) |<1.5$}. Differential cross sections as functions of p_T(D^{*\pm}), $\eta(D^{*\pm}), W$ and $Q^2$ are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and $\eta$(D^{*\pm}), the charm contribution $F_2^{c\bar{c}}(x,Q^2)$ to the proton structure function is determined for Bjorken $x$ between 2 $\cdot$ 10$^{-4}$ and 5 $\cdot$ 10$^{-3}$.Comment: 17 pages including 4 figure

Observation of Scaling Violations in Scaled Momentum Distributions at HERA

Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of $x$ and $Q^2$ using the ZEUS detector. The evolution of the scaled momentum, $x_p$, with $Q^2,$ in the range 10 to 1280 $GeV^2$, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of $Q^2$.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde