3,566 research outputs found
Produção de mudas de almeirão e cultivo no campo, em sistema agroecológico.
Objetivou-se, neste trabalho, avaliar o desenvolvimento das mudas de almeirão em diferentes substratos orgânicos e verificar o comportamento em bandejas, após o transplante no campo e na pós-colheita, constituindo três experimentos. Foram avaliados o uso do substrato comercial e quatro misturas de proporções de composto, areia e pó de basalto. Foram quatro fases de avaliação: aos 13 e 26 dias após a emergência (DAE), aos 74 dias após o transplante e na pós-colheita. Avaliaram-se o comprimento e a massa da matéria seca de raiz e de parte aérea, número de folhas por planta, diâmetro do coleto, área foliar e a conservação pós-colheita. O composto orgânico e as misturas foram superiores ao substrato comercial, na maioria das características avaliadas nos 13 e 26 DAE; entretanto, o substrato comercial superou os demais tratamentos para o comprimento de raiz. Os substratos orgânicos (T2 e T3) podem ser recomendados para a produção de mudas de almeirão com desenvolvimento satisfatório em sistema de cultivo em bandejas e a campo e, de igual forma, em pós-colheita; o uso de composto orgânico como substrato para produção de mudas propiciou o desenvolvimento de mudas mais vigorosas e plantas mais resistentes no campo do que o substrato comercial
Proposta participativa de governança da pegada de carbono na aquicultura.
A aquicultura é uma fonte vital de proteína para a população mundial e, quando gerenciada de forma responsável, pode enfrentar desafios alimentares e ambientais. No entanto, sua pegada de carbono precisa de monitoramento. A Agenda 2030 da ONU e o Plano Nacional de Desenvolvimento da Aquicultura (PNDA) destacam a importância de práticas sustentáveis. O I Encontro Nacional sobre Pegada de Carbono na Aquicultura em 2023 buscou diretrizes e governança de forma participativa para o desenvolvimento sustentável da atividade.Evento virtual
Biochemistry of mansonic schistosomiasis: V - mitochondrial activity in livers and kidneys of marmosets (Callitrix penicillata) infected with Schistosoma mansoni
Foram estudadas mitocôndrias isoladas de fígados e rins de sagüis (Callitrix penicillata) infestados pela inoculação de 200 cercárias e entre 80 e 100 dias de infecção, nos aspectos relativos às suas atividades respiratórias endógenas, bem como frente ao succinato e ao alfa ceto glutarato de sódio. Cada experiência foi acompanhada de controle, usando-se mitocôndrias isoladas de fígados e rins de animais não infectados. As medidas das atividades respiratórias foram efetuadas polarograficamente e expressas em microlitros de oxigênio consumidos por miligrama de proteínas totais por minuto. Os resultados mostraram que as respirações endógenas das mitocôndrias isoladas dos animais infectados foram sempre maiores do que aquelas observadas nos controles. Detectou-se um estímulo para o fígado de 217% e para o rim de 84%. O succinato de sódio estimulou em 85% a respiração das mitocôndrias dos fígados dos animais controles, enquanto a inibiu de 39% nos infectados. Com referência aos rins, este mesmo substrato estimulou a referida respiração tanto nos controles quanto nos infectados, em 89% e 94% respectivamente. O alfa ceto glutarato estimulou as mitocôndrias hepáticas isoladas dos controles em 48% e as renais em 84%. Nos animais esquistossomóticos ou ele não modificou a capacidade respiratória mitocondrial como se observou para o rim, ou a inibiu de 58%, no caso do fígado. Os dados obtidos sugerem que o fígado sofre muito mais, em termos bioquímicos, com a esquistossomose mansônica do que os rins, pelo menos em nossas condições experimentais. As atividades do sistema enzimático succinato desidrogenase e do complexo alfa ceto glutarato desidrogenase permitiram identificar bioquimicamente, em nossos animais esquistossomóticos, vários graus de lesão celular, principalmente hepáticos, que vão desde os mais simples, decorrentes de modificações da físico-química dos sistemas de membranas, até os mais graves, tipo necrose.Mitochondria isolated from livers and kidneys of marmosets (Callitrix penicillata) wich were infected with 200 cercariae were studied, not less than 80 but not more than 100 days after infection, with regard to their endogenous respiratory activities. Sodium succinate and alpha keto glutarate were used as substrates. Each experiment was compared with a control specimen, using isolated mitochondria of livers and kidneys from non infected animals. The measurement of the respiratory activity was made polarographically and expressed in microliters of oxygen consumed per milligram of total protein per minute. The results showed that the endogenous respiration of mitochondria isolated from infected animals was always greater than those observed in the control specimens. A stimulus of 217% to the liver and of 84% to the kidney were observed. The sodium succinate activated the respiration of the control livers approximately 85% and provoked an inhibition of 39% in the infected marmoset. Concerning the kidneys this same substrate stimulated both, about 84% and 94% respectively. The alpha keto glutarate stimulated the hepatic mitochondrial respiration approximately 48% and the renal respiration about 84%. In reference to the schistosomotic animals, the alpha keto glutarate did not modify the mitochondrial respiratory capacity of the kidney but did inhibit that of the liver by 58%. The data obtained from our experimental conditions suggest that the liver suffers, much more, in biochemical terms, from mansonic schistosomiasis, than do the kidneys. The activities of the succinate dehydrogenase system and of the alpha keto glutarate complex, permitted the biochemical identification of the different degrees of cellular lesions, mainly in the liver, in our schistosomotic marmosets. These lesions varied from the simplest ones, caused by physical-chemical modifications of the membrane systems, to the most serious ones, such as necrosis
Fractional Distillation of Organic Liquid Compounds Produced by Catalytic Cracking of Fats, Oils, and Grease
This work aims to investigate the fractional distillation of organic liquid products (OLP) obtained by catalytic cracking of palm oil (Elaeis guineensis Jacq.) at 450°C, 1.0 atm, with 5, 10, and 15% (wt) Na2CO3, using a stirred tank reactor of 143 L. The fractional distillations of OLP were carried out in laboratory scale with and without reflux using columns of different heights, and a pilot‐packed distillation column with internal reflux. OLP and distillation fractions (gasoline, kerosene, light diesel, and heavy diesel) were physicochemically characterized for density, kinematic viscosity, acid value, saponification value, refractive index, flash point, and copper strip corrosion. The OLP and light diesel fractions were analyzed by Fourier transform infrared spectroscopy (FT‐IR) and gas chromatography‐mass spectrometry (GC‐MS). For the experiments in laboratory scale, the yields of distillates decrease along with column height, with and without reflux, while those of bottoms products increase. The yields of distillates and gas increase with increasing Na2CO3 content, while those of bottoms products decrease. The densities of gasoline, kerosene, and light diesel produced in laboratory scale with reflux superpose exactly those of kerosene, light diesel, and heavy diesel produced in laboratory scale without reflux. The kinematic viscosity decreases with increasing column height for the experiments in laboratory scale. The acid values of distillation fractions decrease along with the column height for the experiments with and without reflux. The FT‐IR of distillation fractions in pilot and laboratory scales identified the presence of aliphatic hydrocarbons and oxygenates. The GC‐MS analysis identified OLP composition of 92.84% (area) hydrocarbons and 7.16% (area) oxygenates. The light diesel fraction contains 100% hydrocarbons with an acid value of 0.34 mg KOH/g, proving the technical feasibility of OLP de‐acidification by the fractional distillation process
Accurate Atmospheric Parameters at Moderate Resolution Using Spectral Indices: Preliminary Application to the MARVELS Survey
Studies of Galactic chemical and dynamical evolution in the solar
neighborhood depend on the availability of precise atmospheric parameters
(Teff, [Fe/H] and log g) for solar-type stars. Many large-scale spectroscopic
surveys operate at low to moderate spectral resolution for efficiency in
observing large samples, which makes the stellar characterization difficult due
to the high degree of blending of spectral features. While most surveys use
spectral synthesis, in this work we employ an alternative method based on
spectral indices to determine the atmospheric parameters of a sample of nearby
FGK dwarfs and subgiants observed by the MARVELS survey at moderate resolving
power (R~12,000). We have developed three codes to automatically normalize the
observed spectra, measure the equivalent widths of the indices and, through the
comparison of those with values calculated with pre-determined calibrations,
derive the atmospheric parameters of the stars. The calibrations were built
using a sample of 309 stars with precise stellar parameters obtained from the
analysis of high-resolution FEROS spectra. A validation test of the method was
conducted with a sample of 30 MARVELS targets that also have reliable
atmospheric parameters from high-resolution spectroscopic analysis. Our
approach was able to recover the parameters within 80 K for Teff, 0.05 dex for
[Fe/H] and 0.15 dex for log g, values that are lower or equal to the typical
external uncertainties found between different high-resolution analyzes. An
additional test was performed with a subsample of 138 stars from the ELODIE
stellar library and the literature atmospheric parameters were recovered within
125 K for Teff, 0.10 dex for [Fe/H] and 0.29 dex for log g. These results show
that the spectral indices are a competitive tool to characterize stars with the
intermediate resolution spectra.Comment: Accepted for publication in AJ. Abstract edited to comply with arXiv
standards regarding the number of character
Correction: Diniz et al. Silver Nanoparticles-Composing Alginate/Gelatine Hydrogel Improves Wound Healing In Vivo. Nanomaterials 2020, 10, 390
In the original publication, there was a mistake in Figure 6 as published [...]info:eu-repo/semantics/publishedVersio
Photometric redshifts and clustering of emission line galaxies selected jointly by DES and eBOSS
We present the results of the first test plates of the extended Baryon
Oscillation Spectroscopic Survey. This paper focuses on the emission line
galaxies (ELG) population targetted from the Dark Energy Survey (DES)
photometry. We analyse the success rate, efficiency, redshift distribution, and
clustering properties of the targets. From the 9000 spectroscopic redshifts
targetted, 4600 have been selected from the DES photometry. The total success
rate for redshifts between 0.6 and 1.2 is 71\% and 68\% respectively for a
bright and faint, on average more distant, samples including redshifts measured
from a single strong emission line. We find a mean redshift of 0.8 and 0.87,
with 15 and 13\% of unknown redshifts respectively for the bright and faint
samples. In the redshift range 0.6<z<1.2, for the most secure spectroscopic
redshifts, the mean redshift for the bright and faint sample is 0.85 and 0.9
respectively. Star contamination is lower than 2\%. We measure a galaxy bias
averaged on scales of 1 and 10~Mpc/h of 1.72 \pm 0.1 for the bright sample and
of 1.78 \pm 0.12 for the faint sample. The error on the galaxy bias have been
obtained propagating the errors in the correlation function to the fitted
parameters. This redshift evolution for the galaxy bias is in agreement with
theoretical expectations for a galaxy population with MB-5\log h < -21.0. We
note that biasing is derived from the galaxy clustering relative to a model for
the mass fluctuations. We investigate the quality of the DES photometric
redshifts and find that the outlier fraction can be reduced using a comparison
between template fitting and neural network, or using a random forest
algorithm
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