27,458 research outputs found
BRS Cohomology of Zero Curvature Systems II. The Noncomplete Ladder Case
The Yang-Mills type theories and their BRS cohomology are analysed within the
zero curvature formalism.Comment: 14 pages, latex, no figures, latex improve
Cosmic homogeneity: a spectroscopic and model-independent measurement
Cosmology relies on the Cosmological Principle, i.e., the hypothesis that the
Universe is homogeneous and isotropic on large scales. This implies in
particular that the counts of galaxies should approach a homogeneous scaling
with volume at sufficiently large scales. Testing homogeneity is crucial to
obtain a correct interpretation of the physical assumptions underlying the
current cosmic acceleration and structure formation of the Universe. In this
Letter, we use the Baryon Oscillation Spectroscopic Survey to make the first
spectroscopic and model-independent measurements of the angular homogeneity
scale . Applying four statistical estimators, we show that the
angular distribution of galaxies in the range 0.46 < z < 0.62 is consistent
with homogeneity at large scales, and that varies with
redshift, indicating a smoother Universe in the past. These results are in
agreement with the foundations of the standard cosmological paradigm.Comment: 5 pages, 2 figures, Version accepted by MNRA
Fast method for the determination of short-chain-length polyhydroxyalkanoates (scl-PHAs) in bacterial samples by In Vial-Thermolysis (IVT)
none8siA new method based on the GC–MS analysis of thermolysis products obtained by treating bacterial
samples at a high temperature (above 270 C) has been developed. This method, here named “In-Vial-
Thermolysis” (IVT), allowed for the simultaneous determination of short-chain-length polyhydrox-
yalkanoates (scl-PHA) content and composition. The method was applied to both single strains and
microbial mixed cultures (MMC) fed with different carbon sources.
The IVT procedure provided similar analytical performances compared to previous Py-GC–MS and Py-
GC-FID methods, suggesting a similar application for PHA quantitation in bacterial cells. Results from the
IVT procedure and the traditional methanolysis method were compared; the correlation between the
two datasets was
fit for the purpose, giving a R2 of 0.975. In search of further simplification, the rationale
of IVT was exploited for the development of a “field method” based on the titration of thermolyzed
samples with sodium hydrogen carbonate to quantify PHA inside bacterial cells. The accuracy of the IVT
method was
fit for the purpose.
These results lead to the possibility for the on-line measurement of PHA productivity. Moreover, they
allow for the fast and inexpensive quantification/characterization of PHA for biotechnological process
control, as well as investigation over various bacterial communities and/or feeding strategies.mixedF. Abbondanzi; G. Biscaro; G. Carvalho; L. Favaro; P. Lemos; M. Paglione; C. Samorì; C. TorriF. Abbondanzi; G. Biscaro; G. Carvalho; L. Favaro; P. Lemos; M. Paglione; C. Samorì; C. Torr
Distribution of epicenters in the Olami-Feder-Christensen model
We show that the well established Olami-Feder-Christensen (OFC) model for the
dynamics of earthquakes is able to reproduce a new striking property of real
earthquake data. Recently, it has been pointed out by Abe and Suzuki that the
epicenters of earthquakes could be connected in order to generate a graph, with
properties of a scale-free network of the Barabasi-Albert type. However, only
the non conservative version of the Olami-Feder-Christensen model is able to
reproduce this behavior. The conservative version, instead, behaves like a
random graph. Besides indicating the robustness of the model to describe
earthquake dynamics, those findings reinforce that conservative and non
conservative versions of the OFC model are qualitatively different. Also, we
propose a completely new dynamical mechanism that, even without an explicit
rule of preferential attachment, generates a free scale network. The
preferential attachment is in this case a ``by-product'' of the long term
correlations associated with the self-organized critical state. The detailed
study of the properties of this network can reveal new aspects of the dynamics
of the OFC model, contributing to the understanding of self-organized
criticality in non conserving models.Comment: 7 pages, 7 figure
Repeatability of traits evaluated in a split-plot or factorial experiment.
In this paper repeatability expressions are derived and their respective ANOVA estimators obtained by using split-plot and factorial models, both in a randomized complete block design. The paper also considers different fixed and random effect models and their assumptions and restrictions. Repeatability estimates, such as the correlation between successive measurements (over time) of the same genotype, always have the same value regardless of the model used, and this allows repeatability to be calculated using models based on the mean of the experimental units (mean of blocks) of each genotype in each time. This independence was not observed for repeatability estimates at the upper limit of broad-sense heritability based on the mean of successive measurements (over time) of the same genotype. The repeatability of traits evaluated in experimental trials of different designs is also discussed
Avaliação de genótipos de girassol nos municípios de Mata Roma e Colinas, MA: ano agrícola 2009/2010.
No ano agrícola 2009/2010, foram conduzidos no estado do Maranhão, nos municípios de Mata Roma e Colinas, dois experimentos de avaliação de genótipos de girassol com objetivo de identificar materiais promissores para produção de grãos e óleo. O espaçamento utilizado foi de 0,80 m entre linhas com plantas distanciadas de 0,30 m. Usou-se adubação de fundação na dosagem de 200 kg da fórmula 05-30-15 ha-1 com micronutrientes (FTE BR-12) e cobertura aos 30 dias após semeadura, usando-se 30 kg de N ha-1 e 30 kg de K2O ha-1. Em Mata Roma,a produtividade de grãos variou de 1.468 kg ha-1 a 1.994 kg ha-1 obtida nos genótipos HLA 44-63 e AGROBEL 960, respectivamente. O teor de óleo variou de 37,5% no genótipo M 734 a 46,3% no HLA 05-62. Para rendimento de óleo verificou-se uma variação de 596 kg ha-1 no genótipo BRS Gira 29 a 895 kg ha-1 no AGROBEL 960. Em Colinas, a produtividade de grãos variou de 1.225 kg ha-1 a 1.654 kg ha-1 , respectivamente, nos genótipos EXP 1456 DM e BRS GIRA 27. Para teor de óleo houve uma variação de 41,1% (M 734) a 49,6% (HLA 887). Quanto ao rendimento de óleo constatou-se uma variação entre 561 kg ha-1 a 723 kg ha-1, respectivamente, nos genótipos M 735 e AROMO 10. EVALUATION OF GENOTYPES OF SUNFLOWER IN MATA ROMA AND COLINAS MARANHÃO STATE, BRAZIL, IN THE AGRICULTURAL YEAR 2009/2010. In the agricultural year 2009/2010, two experiments involving the evaluation of sunflower genotypes were carried out in Mata Roma and Colinas, estate of Maranhão, Brasil. These experiments aimed to identify good material to oil production. Spacing used between lines with plants was 0,80 m and, between plants, 0,30 m. Fertilizers were initially used in the dosage of 200 kg.ha-1 of the formula 05-30-15 with micronutrients (FTE BR-12) and coverage 30 days after sowing, using 30 kg.ha-1 of N and 30 kg.ha-1 of K2O. In Mata Roma, the grain productivity ranged from 1,468 kg.ha-1 to 1,994 kg.ha-1, obtained in genotypes HLA 44-63 and AGROBRL 960, respectively. The oil content ranged from 37.5% with genotype M 734 to 46.3% with genotype HLA 05-62. The oil efficiency ranged from 596 kg.ha-1, with genotype BRS Gira 29, to 895 kg.ha-1 , with genotypes V50070. In Bom Jesus, the grain productivity ranged from 999 kg ha-1 to 1,208 kg ha-1 in genotypes EXP 1456 DM and BRS GIRA 27, respectively. Oil content ranged from 41.1% (M 734) to 49.6% (HLA 887). Finally, oil efficiency ranged from 561 kg.ha-1 to 723 kg.ha-1, respectively, in genotypes M 735 and AROMO 10
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