Accurate staging of reproduction development in Cadenza wheat by non-destructive spike analysis

© 2020 The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Experimental Biology. Wheat is one of the most important crops in the world; however, loss of genetic variability and abiotic stress caused by variable climatic conditions threaten future productivity. Reproduction is critical for wheat yield; however, pollen development is amongst the developmental stages most sensitive to stresses such as heat, cold, or drought. A better understanding of how anther and pollen development is regulated is needed to help produce more resilient crops and ensure future yield increases. However, in cereals such as wheat, barley, and rice, flowers form within the developing pseudostem and therefore accurate staging of floral materials is extremely challenging. This makes detailed phenotypic and molecular analysis of floral development very difficult, particularly when limited plant material is available, for example with mutant or transgenic lines. Here we present an accurate approach to overcome this problem, by non-destructive staging of reproduction development in Cadenza, the widely used spring wheat research variety. This uses a double-scale system whereby anther and pollen development can be predicted in relation to spike size and spike position within the pseudostem. This system provides an easy, reproducible method that facilitates accurate sampling and analysis of floral materials, to enable anther and pollen developmental research

Finite Size Analysis of Luttinger Liquids with a source of 2k_f Scattering

Numerical analysis of the spectrum of large finite size Luttinger liquids (g<1) in the presence of a single source of 2k_f scattering has been made possible thanks to an effective integration of high degrees of freedom. Presence of irrelevant operators and their manifestation in transport are issues treated independently. We confirm the existence of two irrelevant operators: particle hopping and charge oscillations, with regions of dominance separated by g=1/2. Temperature dependence of conductance is shown to be dominated by hopping alone. Frequency dependence is affected by both irrelevant operators.Comment: 4 pages, LaTex (RevTex), 3 PostScript figures appende

Modelo predictivo del índice de anisotropía del semicoque a partir de las propiedades de los carbones de la Cordillera Oriental de Colombia

This study developed a theoretical model for the determination of the Coke Anisotropy Quotient (CAQ) of semi-coke from the properties of its&nbsp;precursor coal. This is an useful parameter to define the resistance and reactivity of semi-coke in the blast furnace. For 36 semi-coke samples, a textural analysis was performed alongside a fluidity test to determine the real CAQ. The main textures observed were: isotropic and circular for high volatile bituminous coals (HVB); lenticular and fine ribbons for the medium volatile bituminous coals (MVB); and medium and thick ribbons for the low volatile bituminous coals (LVB). The CAQ varied in a range from 1 to 11. A principal component analysis (PCA) and multiple regression allowed to discriminated the importance of certain coal properties, in determining the CAQ to be recognized and to estimate parameters of the mathematical model. The statistical analysis suggested that CAQ can be best predicted from the fluidity, volatile matter, and Ro of the parent coals. The veracity of this model result was then tested using a second dataset from Poland. This work optimizes the usefulness of standard datasets in the prediction of CAQ's offering a means of quality control that could be implemented in Colombian coke production.En esta investigación se desarrolló un modelo teórico para la determinación del Cociente de Anisotropía del Coque (CAQ) del semicoque a partir de las propiedades de su carbón precursor. El CAQ permite definir la resistencia y la reactividad del semicoque en el alto horno. Usando material residual de las pruebas de fluidez se realizó un análisis textural para determinar el CAQ real sobre 36 muestras de semicoque. Las principales texturas observadas para los carbones bituminosos fueron: isotrópicas y circulares para los de alta volatilidad (HVB); cintas lenticulares y finas para los de media volatilidad (MVB); y cintas medias y gruesas para los de baja volatilidad (LVB). El CAQ varió en un rango de 1 a 11. Análisis de componentes principales (PCA) y regresión múltiple permitieron reconocer la importancia de ciertas propiedades del carbón para determinar el CAQ. El análisis estadístico sugirió que el CAQ puede predecirse mejor a partir de la fluidez,la materia volátil y el Ro de los carbones precursores. Este modelo fue&nbsp;validado a través de la comparación con datos reales de carbones de Polonia. Este trabajo proporciona un medio de control de calidad que podríaimplementarse en la producción de coque colombiano.&nbsp

Mid-J CO emission from the Orion BN/KL explosive outflow

High spatial resolution low-J 12CO observations have shown that the wide-angle outflow seen in the Orion BN/KL region correlates with the famous H2 fingers. Recently, high-resolution large-scale mappings of mid- and higher-J CO emissions have been reported toward the Orion molecular cloud 1 core region using the APEX telescope. Therefore, it is of interest to investigate this outflow in the higher-J 12CO emission, which is likely excited by shocks. The observations were carried out using the dual-color heterodyne array CHAMP+ on the APEX telescope. The images of the Orion BN/KL region were obtained in the 12CO J=6-5 and J=7-6 transitions with angular resolutions of 8.6 and 7.4 arcsec, respectively. The results show a good agreement between our higher-J 12CO emission and SMA low-J 12CO data, which indicates that this wide-angle outflow in Orion BN/KL is likely the result of an explosive event that is related to the runaway objects from a dynamically decayed multiple system. From our observations, we estimate that the kinetic energy of this explosive outflow is about 1-2x10^47 erg. In addition, a scenario has been proposed where part of the outflow is decelerated and absorbed in the cloud to explain the lack of CO bullets in the southern part of BN/KL, which in turn induces the methanol masers seen in this region.Comment: 5 pages, 4 figure

Real Space Renormalization Group Methods and Quantum Groups

We apply real-space RG methods to study two quantum group invariant Hamiltonians, that of the XXZ model and the Ising model in a transverse field defined in an open chain with appropiate boundary terms. The quantum group symmetry is preserved under the RG transformation except for the appearence of a quantum group anomalous term which vanishes in the classical case. We obtain correctly the line of critical XXZ models. In the ITF model the RG-flow coincides with the tensor product decomposition of cyclic irreps. of $SU_q(2)$ with $q^4=1$.Comment: 7 pages, LATEX, no figure

QUIMICA MINERAL DE LAS ROCAS DE ALTA PRESION - FACIES ECLOGITA, DE LA PENINSULA DE LA GUAJIRA, COLOMBIA

The high pressure rocks found in the Guajira Peninsula, comprise mainly eclogites with the peak metamorphic paragenesis: omphacite + garnet + quartz + white mica ± kyanite and metapelites with the peak metamorphic paragénesis: quartz + white mica + garnet + kyanite + rutile ± apatite. These rocks register a complex history of tectonic evolution: 1) Prograde growth in two stages, through amphibolite facies, reaching the peak metamorphic paragénesis; 2) hydration of these rocks that enabled galucophane to grow locally; 3) a later not well characterized event that happened in static conditions shown by the growth of clinozoisite; 4) retrogression through amphibolite-facies. The association of eclogites with continental rocks suggest their link to an accretionary prism that was generated during the Cretaceous subduction of the Caribbean plate and the bringing together of a possible continental fragment or the South American continental margin and the Caribbean plate. Key words : Eclogites, metapelites, Caribbean plate, mineral chemistry &nbsp;Las rocas de alta presión encontradas en la Península de La Guajira, comprenden principalmente eclogitas con la paragénesis pico: onfacita + granate + cuarzo + rutilo + mica blanca ± cianita y metapelitas con la paragénesis pico: cuarzo + mica blanca + granate + cianita + rutilo ± apatito. Estas rocas muestran evidencias de una compleja historia de evolución tectónica: 1) Una primera fase de crecimiento prógrado en dos fases, a través de la facies anfibolita, hasta alcanzar la paragénesis pico; 2) un evento de hidratación que permitió la formación local de glaucofana orientada; 3) un evento no bien diferenciado que sucede en condiciones estáticas que permite la formación de clinozoisita; y 4) la retrogradación de estas rocas en facies anfibolita. La asociación de metamafitas y rocas de procedencia continental sugieren una relación con un prisma de acreción que se generó durante la subducción cretácica de la placa Caribe y el acercamiento de un posible fragmento continental o de la margen continental Suramericana a la placa del Caribe. Palabras Clave: Eclogitas, metapelitas, placa Caribe, química mineral &nbsp; &nbsp; &nbsp

QUIMICA MINERAL DE LAS ROCAS DE ALTA PRESION - FACIES ECLOGITA, DE LA PENINSULA DE LA GUAJIRA, COLOMBIA

The high pressure rocks found in the Guajira Peninsula, comprise mainly eclogites with the peak metamorphic paragenesis: omphacite + garnet + quartz + white mica ± kyanite and metapelites with the peak metamorphic paragénesis: quartz + white mica + garnet + kyanite + rutile ± apatite. These rocks register a complex history of tectonic evolution: 1) Prograde growth in two stages, through amphibolite facies, reaching the peak metamorphic paragénesis; 2) hydration of these rocks that enabled galucophane to grow locally; 3) a later not well characterized event that happened in static conditions shown by the growth of clinozoisite; 4) retrogression through amphibolite-facies. The association of eclogites with continental rocks suggest their link to an accretionary prism that was generated during the Cretaceous subduction of the Caribbean plate and the bringing together of a possible continental fragment or the South American continental margin and the Caribbean plate. Key words : Eclogites, metapelites, Caribbean plate, mineral chemistry &nbsp;Las rocas de alta presión encontradas en la Península de La Guajira, comprenden principalmente eclogitas con la paragénesis pico: onfacita + granate + cuarzo + rutilo + mica blanca ± cianita y metapelitas con la paragénesis pico: cuarzo + mica blanca + granate + cianita + rutilo ± apatito. Estas rocas muestran evidencias de una compleja historia de evolución tectónica: 1) Una primera fase de crecimiento prógrado en dos fases, a través de la facies anfibolita, hasta alcanzar la paragénesis pico; 2) un evento de hidratación que permitió la formación local de glaucofana orientada; 3) un evento no bien diferenciado que sucede en condiciones estáticas que permite la formación de clinozoisita; y 4) la retrogradación de estas rocas en facies anfibolita. La asociación de metamafitas y rocas de procedencia continental sugieren una relación con un prisma de acreción que se generó durante la subducción cretácica de la placa Caribe y el acercamiento de un posible fragmento continental o de la margen continental Suramericana a la placa del Caribe. Palabras Clave: Eclogitas, metapelitas, placa Caribe, química mineral &nbsp; &nbsp; &nbsp

Constraining the Kahler Moduli in the Heterotic Standard Model

Phenomenological implications of the volume of the Calabi-Yau threefolds on the hidden and observable M-theory boundaries, together with slope stability of their corresponding vector bundles, constrain the set of Kaehler moduli which give rise to realistic compactifications of the strongly coupled heterotic string. When vector bundles are constructed using extensions, we provide simple rules to determine lower and upper bounds to the region of the Kaehler moduli space where such compactifications can exist. We show how small these regions can be, working out in full detail the case of the recently proposed Heterotic Standard Model. More explicitely, we exhibit Kaehler classes in these regions for which the visible vector bundle is stable. On the other hand, there is no polarization for which the hidden bundle is stable.Comment: 28 pages, harvmac. Exposition improved, references and one figure added, minor correction

Relativistic hydrodynamics on spacelike and null surfaces: Formalism and computations of spherically symmetric spacetimes

We introduce a formulation of Eulerian general relativistic hydrodynamics which is applicable for (perfect) fluid data prescribed on either spacelike or null hypersurfaces. Simple explicit expressions for the characteristic speeds and fields are derived in the general case. A complete implementation of the formalism is developed in the case of spherical symmetry. The algorithm is tested in a number of different situations, predisposing for a range of possible applications. We consider the Riemann problem for a polytropic gas, with initial data given on a retarded/advanced time slice of Minkowski spacetime. We compute perfect fluid accretion onto a Schwarzschild black hole spacetime using ingoing null Eddington-Finkelstein coordinates. Tests of fluid evolution on dynamic background include constant density and TOV stars sliced along the radial null cones. Finally, we consider the accretion of self-gravitating matter onto a central black hole and the ensuing increase in the mass of the black hole horizon.Comment: 23 pages, 13 figures, submitted to Phys. Rev.

Multi-site, multi-year monitoring of the oscillating Algol-type eclipsing binary CT Her

We present the results of a multi-site photometric campaign carried out in 2004-2008 for the Algol-type eclipsing binary system CT Her, the primary component of which shows Delta Scuti-type oscillations. Our data consist of differential light curves collected in the filters B and V which have been analysed using the method of Wilson-Devinney (PHOEBE). After identification of an adequate binary model and removal of the best-matching light curve solution, we performed a Fourier analysis of the residual B and V light curves to investigate the pulsational behaviour. We confirm the presence of rapid pulsations with a main period of 27.2 min. Up to eight significant frequencies with semi-amplitudes in the range 3 to 1 mmag were detected, all of which surprisingly lie in the frequency range 43.5-53.5 c\d. This result is independent from the choice of the primary's effective temperature (8200 or 8700 K) since the light curve models for the binary are very similar in both cases. This is yet another case of a complex frequency spectrum observed for an accreting Delta Scuti-type star (after Y Cam). In addition, we demonstrate that the amplitudes of several of these pulsation frequencies show evidence of variability on time scales as short as 1-2 years, perhaps even less. Moreover, our analysis takes into account some recently acquired spectra, from which we obtained the corresponding radial velocities for the years 2007-2009. Investigation of the O-C diagram shows that further monitoring of the epochs of eclipse minima of CT Her will cast a new light on the evolution of its orbital period.Comment: 13 pages, 13 encapsulated Postscript figures. Tables~3, 4, 9 and 12 will be available in electronic form only. Astronomy and Astrophysics, in process (2011). Replaced the abstract with its final versio