425 research outputs found
Produtividade do amendoinzeiro (Avachia hypogaea cv. Tatu-53) sob adubação foliar com fitoreguladores
Two nutrient foliar sprays, namely Ferti-Foliage (21-21 -21) and Wuxal (9-9-7), were applied to peanut plants under field conditions. Both were applied 23 days after germination of seeds, at the beginning of flowering, and during flowering. Other treatments were application of NPK fertilizer (9-30-16, 250 kg/ha) into the soil and check (no fertilizer). The experiment was carried out on a latosolic B "Terra Roxa" soil, sowing being made on March 6th and harvest on July 10th. Statistical analysis showed no significant differences amongst treatments. However, certain treatments had better yields. For instance, application of Ferti-Foliage showed a tendency to increasing number of pods per plant and number of seeds per pod. Same product when applied at the beginning of flowering had a tendency to increase production of seeds and of forage. Application of NPK (9-30-16) into the soil showed similar results.Para estudar o efeito da aplicação de adubos foliares com fitoreguladores na produtividade do amendoinzeiro 'Tatu - 53', efetuou-se ensaio em uma Terra Roxa Estruturada, na Faculdade de Ciências Agrárias de Jaboticabal (SP) . O experimento constou da aplicação, em diferentes épocas, dos adubos foiiares Ferti-Foiiage (21-21-21) e Wuxal (9-9-7) para NPK. Para isto realizaram - se os tratamentos controle sem adubação, aduba çao no solo de 250 kg/ha da formulação (9 -30-16) para NPK, Ferti-Foliage aplicado 23 dias após a emergência, Ferti-Foliage aplicado no início do florescimento e Ferti-Foliage aplicado em pleno florescimento. Além disso aplicou-se Wuxal 23 dias após a emergência, Wuxal no início do florescimento e Wuxal em pleno florescimento. Devido á fertilidade natural do solo utilizado, não se observaram diferenças significativas entre os tratamentos. Verificou-se porém, uma tendência de aumento no numero de vagens e de sementes nas plantas tratadas com Ferti-Foliage nas diferentes épocas. Ferti-Foliage, (21-21-21), aplicado no início da florescência, tendeu a elevar também a produção de sementes e de palhada do amendoinzeiro. Aplicaçao de NPK (9-30-16) 250 kg/ha, no plantio, mostrou tendência de aumentar a produção de sementes e o peso da palhada
Spatial averaging and apparent acceleration in inhomogeneous spaces
As an alternative to dark energy that explains the observed acceleration of
the universe, it has been suggested that we may be at the center of an
inhomogeneous isotropic universe described by a Lemaitre-Tolman-Bondi (LTB)
solution of Einstein's field equations. To test this possibility, it is
necessary to solve the null geodesics. In this paper we first give a detailed
derivation of a fully analytical set of differential equations for the radial
null geodesics as functions of the redshift in LTB models. As an application we
use these equaions to show that a positive averaged acceleration obtained
in LTB models through spatial averaging can be incompatible with cosmological
observations. We provide examples of LTB models with positive which fail
to reproduce the observed luminosity distance . Since the apparent
cosmic acceleration is obtained from fitting the observed luminosity
distance to a FLRW model we conclude that in general a positive in LTB
models does not imply a positive .Comment: 16 pages, 12 figures. Explicit derivation of the fully analytical
null geodesic equations has been added. Published in GR
Supernova neutrinos and antineutrinos: ternary luminosity diagram and spectral split patterns
In core-collapse supernovae, the nu_e and anti-nu_e species may experience
collective flavor swaps to non-electron species nu_x, within energy intervals
limited by relatively sharp boundaries ("splits"). These phenomena appear to
depend sensitively upon the initial energy spectra and luminosities. We
investigate the effect of generic variations of the fractional luminosities
(l_e, l_{anti-e}, l_x) with respect to the usual "energy equipartition" case
(1/6, 1/6, 1/6), within an early-time supernova scenario with fixed thermal
spectra and total luminosity. We represent the constraint l_e+l_{anti-e}+4l_x=1
in a ternary diagram, which is explored via numerical experiments (in
single-angle approximation) over an evenly-spaced grid of points. In inverted
hierarchy, single splits arise in most cases, but an abrupt transition to
double splits is observed for a few points surrounding the equipartition one.
In normal hierarchy, collective effects turn out to be unobservable at all grid
points but one, where single splits occur. Admissible deviations from
equipartition may thus induce dramatic changes in the shape of supernova
(anti)neutrino spectra. The observed patterns are interpreted in terms of
initial flavor polarization vectors (defining boundaries for the single/double
split transitions), lepton number conservation, and minimization of potential
energy.Comment: 24 pages, including 14 figures (1 section with 2 figures added).
Accepted for publication in JCA
Supernova neutrino three-flavor evolution with dominant collective effects
Neutrino and antineutrino fluxes from a core-collapse galactic supernova are
studied, within a representative three-flavor scenario with inverted mass
hierarchy and tiny 1-3 mixing. The initial flavor evolution is dominated by
collective self-interaction effects, which are computed in a full three-family
framework along an averaged radial trajectory. During the whole time span
considered (t=1-20 s), neutrino and antineutrino spectral splits emerge as
dominant features in the energy domain for the final, observable fluxes. Some
minor or unobservable three-family features (e.g., related to the
muonic-tauonic flavor sector) are also discussed for completeness. The main
results can be useful for SN event rate simulations in specific detectors.Comment: 22 pages, including 9 figures (1 section with 3 figures added).
Accepted for publication in JCA
Lethality by pneumonia and factors associated to death
AbstractObjectiveto describe the case-fatality rate (CFR) and risk factors of death in children with community-acquired acute pneumonia (CAP) in a pediatric university hospital.Methoda longitudinal study was developed with prospective data collected from 1996 to 2011. Patients aged 1 month to 12 years were included in the study. Those who left the hospital against medical orders and those transferred to ICU or other units were excluded. Demographic and clinical-etiological characteristics and the initial treatment were studied. Variables associated to death were determined by bivariate and multivariate analysis using logistic regression.Resultsa total of 871 patients were selected, of whom 11 were excluded; thus 860 children were included in the study. There were 26 deaths, with a CFR of 3%; in 58.7% of these, penicillin G was the initial treatment. Pneumococcus was the most common pathogen (50.4%). From 1996 to 2000, there were 24 deaths (93%), with a CFR of 5.8% (24/413). From 2001 to 2011, the age group of hospitalized patients was older (p = 0.03), and the number of deaths (p = 0.02) and the percentage of disease severity were lower (p = 0.06). Only disease severity remained associated to death in the multivariate analysis (OR = 3.2; 95%CI: 1.2-8.9; p = 0.02).Conclusionwhen the 1996-2000 and 2001-2011 periods were compared, a significant reduction in CFR was observed in the latter, as well as a change in the clinical profile of the pediatric inpatients at the institute. These findings may be related to the improvement in the socio-economical status of the population. Penicillin use did not influence CFR
Effects of inhomogeneities on apparent cosmological observables: "fake" evolving dark energy
Using the exact Lemaitre-Bondi-Tolman solution with a non-vanishing
cosmological constant , we investigate how the presence of a local
spherically-symmetric inhomogeneity can affect apparent cosmological
observables, such as the deceleration parameter or the effective equation of
state of dark energy (DE), derived from the luminosity distance under the
assumption that the real space-time is exactly homogeneous and isotropic. The
presence of a local underdensity is found to produce apparent phantom behavior
of DE, while a locally overdense region leads to apparent quintessence
behavior. We consider relatively small large scale inhomogeneities which today
are not linear and could be seeded by primordial curvature perturbations
compatible with CMB bounds. Our study shows how observations in an
inhomogeneous CDM universe with initial conditions compatible with the
inflationary beginning, if interpreted under the wrong assumption of
homogeneity, can lead to the wrong conclusion about the presence of "fake"
evolving dark energy instead of .Comment: 22 pages, 19 figures,Final version to appear in European Physical
Journal
Ação de estimulantes vegetais no comportamento do feijoeiro (Phaseolus vulgaris L. cv. goiano precoce)
This research deals with the effects of Pix, Atonik, Ergostim and Cytozyme application on behavior of beans (Phaseolus vulgaris L. cv. Goiano Precoce), under greenhouse conditions. Beans were sowing in pots and Pix and Atonik (1.0 l/ha), Ergostim (0.5 l/ha) and Cytozyme (2.0 l/ha) were applied 30 days after sowing. Ergostim promoted growth and presented a tendency to increase number of pods and seeds, and reduced K/r ratio. Pix presented a tendency to increase number of pods, K/r ratio and protein level in the seeds. Atonik and Cytozyme did not promote changes in the parameters studied.Este ensaio foi realizado com o objetivo de estudar os efeitos de estimulantes vegetais no desenvolvimento do feijoeiro 'Goiano Precoce', em condições de casa de vegetaçio. Pix (cloreto de mepiquat), Atonik (mononitroguaiacolsódico + compostos nitroaromáticos), Ergostim (AATC + ácido fólico) e Cytozyme (citocinina + derivados de etoxilato-siloxano + outros compostos) foram aplicados, 30 dias após a semeadura, nas dosagens de 1,0; 1,0; 0,5 e 2,0 l/ha, respectivamente. Verificou-se que Ergostim causou maior crescimento e apresentou uma tendência de aumentar o número de vagens e sementes, tendo reduzido a relação K/r. Pix mostrou uma tendência de aumentar o número de vagens, a relação K/r e o teor de proteína nas sementes. Atonik e Cytozyme não provocaram modificações nos parâmetros estudados
Efeito de reguladores de crescimento no potencial osmótico de tomateiro (Lycopersicon esculentum Mill. cv. Angela)
This research deals with the effects of exogenous growth regulators on leaf osmotic potential of tomato cultivar "Angela". To study the influence of growth substances on osmotic potentia, (2-chloroethyl) trimethylammonium chloride (CCC) at concentration of 2,000 ppm, succinic acid-2,2-dirnethylhydrazide (Alar) (3,000 ppm), and potassium gibberellate (Gibrel) (100 ppm) were applied. The leaf osmotic potential established everyday during six days showed that plants treated with Gibrel presented lower (negative) osmotic potential. CCC promoted better equilibrium in the osmotic potential of tomato plants. Leaves of tomato cultivar "Angela" presented higher osmotic potential in the morning in relation to leaves collected in the afternoon.A importância do estudo do potencial osmótico das plantas deve-se ao fato deste parâmetro ser considerado o principal componente do potencial hídrico, refletindo o equilíbrio de água na planta. Determinou-se o potencial osmótico foliar do tomateiro (Lycopersicon esculentum Mill. cv. "Angela") através de osmômetro de precisão. As plantas haviam sido tratadas com cloreto de (2-cloroetil) trimetilamônio (CCC) 2000 ppm, ácido succínico-2,2-dimetilhidrazida (Alar) 3000 ppm e giberelato de potássio (Gibrel) 100 ppm, além do controle. Verificou-se que o Gibrel promoveu uma redução no potencial osmótico; sendo que Alar provocou flutuações no potencial do tomateiro "Angela". O CCC causou maior equilíbrio no potencial osmótico foliar do tomateiro. Observou-se que as folhas da cultivar "Angela'' mostraram potencial osmótico mais alto pela manhã com relação ao período da tarde
Efeitos da salinidade em algodoeiros tratados com produtos químicos
Studies were carried out to establish the effects of spray of polyethylene polysulfide (5%), oxyethylene docosanol (5%) and succinic acid-2,2-dimethylhydrazide (2,000 ppm), in the growth of cotton 'IAC-RM3', under application of N-P-K (5:10:5) and irrigation with solution of NaCl - CaCl2 - MgCl2 (1.00:0.85:0.15). The antitranspirants promote increase in leaf area of cotton; and the growth retardant causes diminution in the leaf area in relation to check in salinity conditions. The chemicals promote increase in the dry weight in relation to check. The net assimilation rate and the relative growth rate were superior in the plots that received the chemicals in relation to check in salinity conditions. It was not verified differences between the plants treated with antitranspirants and the check in relation to the leaf area ratio; that parameter was inferior in the treatment with the growth retardant.Estudaram-se os efeitos de polissulfeto de polietileno (0,5%), o-xietileno docosanol (5%) e ácido succínico - 2,2-dimetil-hidrazida (2000 ppm), aplicados em pulverização, no desenvolvimento de algo-doeiro cultivar 'IAC-RM3', submetido à adubação N-P-K (5:10 5) e à irrigação com solução de NaCl - CaCl2 - MgCl2 (1,000,85:0,15). Os antitranspirantes permitiram aumento em área foliar do algo-doeiro; sendo que o retardador de crescimento provocou redução na área foliar com relação ao controle, em condições de salinidade. Os produtos químicos promoveram maior aumento no peso seco em relação ao controle. A taxa assimilatória líquida e a taxa de crescimento relativo mostraram-se mais altas nas plantas tratadas com produtos químicos em relação ao controle, nas condições de salinidade. N ao ocorreram diferenças marcantes entre as plantas tratadas com antitranspirantes e o controle, com relação à razão de área foliar; sendo que este parâmetro mostrou-se inferior no tratamento com retardador de crescimento
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