4,463 research outputs found
Detection of flour or farina from Triticum aestivum in macaroni by starch-gel electrophoresis of water-soluble proteins
A water-soluble protein component, A, has been found which appears without exception at a higher concentration in Triticum aestivum than in T. durum. Quantitation of A is achieved by referring the height of densitogram peak A to the height of peak B, which corresponds to a second component that is present in all varieties studied from both species. Extreme valúes of peak height ratio (PHR) in both species are tentatively established. On the basis of these valúes, the máximum and minimum possible contents of T. aestivum in a mixture are expressed as a function of PHR. All the varieties of T. aestivum studied are detected when they contribute more than 60% to the mixture. In over 90% of all possible binary combinations between varieties of T. aestivum and T. durum, the máximum proportion of undetected T. aestivum has been 30%
Genetic control of purothionins in wheat: problems of the aneuploid analysis when searching for regulatory genes
The study of the genetic control of purothionins in wheat endosperm illustrates some of the problems and pitfalls faced in aneuploid analysis of regulatory effects. Biochemical and genetic evidence is presented indicating that the possible regulatory effect of genes located in group 5 chromosomes on the expression of the purothionin structural genes located in group 1 chromosomes is not actually operating "in vivo"
Expression of homoeologous molecular systems in wheat alloploids
Allopolyploidy is widespread in the plant kingdom, where it has been of considerable evolutionary significance. Although the existence of heterotic interactions between the genomes that make up an alloploid have been generally assumed, the precise nature of these interactions has not been extensively investigated. Presently available evidence about metabolic integration of the wheat genomes is examined in search of new insights about the different modes of genome interaction. Although additive expression seems to be the case for many homoeologous systems, more complex patterns of integration have become evident. Examples of enzyme subunit complementation, gene compensation and other dosage effects, holoprotein completion, and complementation of metabolic pathways are discussed
A New method for the estimation of common wheat (Triticum aestivum L.) in pasta products
An electrophoretic component ofthe chloroform-methanol (2:1) extractedproteins from common wheat endosperin is barely detected in durum wheat. This sharp interspecific difference is expressed in per cent units ofanother electrophoretic component which is present in both wheat species and designed protein ratio (PR). Macaroni production processing and/or. variations of milling yield do not significantly affect the PR. A linear relationship exists between PR and the % of common wheat in a known mixture. Tentative interspecific limits for PR are established from a survey of79 common wheat and 30 durum wheat variéties. Basedon these limits, máximum and mínimum possible common wheat contení in an unknown mixture is calculated as a funcí ion of PR
Loss of redundant gene expression after polyploidization in plants
Based on chromosomal location data of genes encoding 28 biochemical systems in allohexaploid wheat,Triticum aestivum L. (genomes AABBDD), it is concluded that the proportions of systems controlled by triplicate, duplicate, and single loci are 57%, 25%, and 18% respectively
Detección y cuantificación de harinas de trigo común ("Triticum vulgare") en sémolas y pastas alimenticias
El método se basa en la detección y cuantificación de un componente designado CM, del extracto cloroformo-metanol del endaspermo de trigo o de productos derivados de él, cuyo control genético radica en el cromosoma ID de •Triticum Vulgarey que por tanto no se encuentra en «T. durum». El mencionado extracto,, al que se designa proteina CM, se fracciona por electroforesis sobre gel de almidón, y e] componente CM| se estima visualmente o se cuantifica densintométricamente
Spherically symmetric loop quantum gravity: analysis of improved dynamics
We study the "improved dynamics" for the treatment of spherically symmetric
space-times in loop quantum gravity introduced by Chiou {\em et al.} in analogy
with the one that has been constructed by Ashtekar, Pawlowski and Singh for the
homogeneous space-times. In this dynamics the polymerization parameter is a
well motivated function of the dynamical variables, reflecting the fact that
the quantum of area depends on them. Contrary to the homogeneous case, its
implementation does not trigger undesirable physical properties. We identify
semiclassical physical states in the quantum theory and derive the
corresponding effective semiclassical metrics. We then discuss some of their
properties. Concretely, the space-time approaches sufficiently fast the
Schwarzschild geometry at low curvatures. Besides, regions where the
singularity is in the classical theory get replaced by a regular but discrete
effective geometry with finite and Planck order curvature, regardless of the
mass of the black hole. This circumvents trans-Planckian curvatures that
appeared for astrophysical black holes in the quantization scheme without the
improvement. It makes the resolution of the singularity more in line with the
one observed in models that use the isometry of the interior of a Schwarzschild
black hole with the Kantowski--Sachs loop quantum cosmologies. One can observe
the emergence of effective violations of the null energy condition in the
interior of the black hole as part of the mechanism of the elimination of the
singularity.Comment: 26 pages, 8 figure
The GALEX View of "Boyajian's Star" (KIC 8462852)
The enigmatic star KIC 8462852, informally known as "Boyajian's Star", has
exhibited unexplained variability from both short timescale (days) dimming
events, and years-long fading in the Kepler mission. No single physical
mechanism has successfully explained these observations to date. Here we
investigate the ultraviolet variability of KIC 8462852 on a range of timescales
using data from the GALEX mission that occurred contemporaneously with the
Kepler mission. The wide wavelength baseline between the Kepler and GALEX data
provides a unique constraint on the nature of the variability. Using 1600
seconds of photon-counting data from four GALEX visits spread over 70 days in
2011, we find no coherent NUV variability in the system on 10-100 second or
months timescales. Comparing the integrated flux from these 2011 visits to the
2012 NUV flux published in the GALEX-CAUSE Kepler survey, we find a 3% decrease
in brightness for KIC 8462852. We find this level of variability is
significant, but not necessarily unusual for stars of similar spectral type in
the GALEX data. This decrease coincides with the secular optical fading
reported by Montet & Simon (2016). We find the multi-wavelength variability is
somewhat inconsistent with typical interstellar dust absorption, but instead
favors a R = 5.0 0.9 reddening law potentially from circumstellar
dust.Comment: 8 pages, 4 figures, ApJ Accepte
Chromosomal control of non-gliadin proteins from the 70% ethanol extract of wheat endosperm
The non-gliadin fraction of the 70% ethanol extracts of compensated nulli-tetrasomics and ditelosomics of Triticum aestivum cv. Chinese Spring has been analyzed by combined electrofocusing and electrophoresis. Seventeen of the 21 protein map components of the euploid have been ascribed to eight chromosomes: 4A, 3BS, 6BS, 7BS, 3D, 4D, 5D and 7DS.
The relationship of the different map components with other proteins previously associated with the same chromosomes is discusse
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