Genetic Variation and Genotype by Environment Interaction of Crown Rust Resistance in Annual Ryegrass (\u3ci\u3eLolium multiflorum\u3c/i\u3e Lam.)

The genetic variation and genotype by environment interaction of crown rust resistance of annual ryegrass (Lolium multiflorum Lam.) was evaluated at two locations in Argentina, as part of the breeding programme in progress at our Institute. Forty half sib families originated from commercial tetraploid cultivars, were grown from seeds in a greenhouse during autumn 1999. At the stage of tillering initiation forty eight plants/familiy were randomly selected and transplanted as spaced plant trial in a randomized design with three replicates, at the two locations. All plants were scored for a range of morphological and phytopatological attributes. The severity of crown rust and the winter dry matter production were assessed on each plant. Crown rust resistance at both evaluation dates, was highly heritable and not affected by environment interaction. By contrast, winter dry matter showed a large family by location interaction and a high environmental influence. The results of the present study indicated that important progress in crown rust resistance in annual ryegrass can be achieved through phenotypic recurrent selection

Genetic Variability Between Adapted Populations of Annual Ryegrass (\u3cem\u3eLolium Multiflorum\u3c/em\u3e Lam) In Argentina

Italian ryegrass (Lolium multiflorum Lam.) is one of the most important annual grasses used in Argentina because it adapts better to the intensive animal system of the Humid Pampas than other annual forage grass. Although much research has been done to study its productive potential and management technologies, little work has focused on breeding and selection. There is ample evidence that genetic variability occurs within grass species (Snaydon, 1987; Andrés and Barufaldi, 1997) both in morphology and physiology. As a result the variation of attributes related with yield potential, quality and adaptation to different management systems, is often used in plant breeding to develop new varieties. The objective of this work was to evaluate the genetic variability between 32 populations of annual ryegrass adapted to different grassland environments in the Humid Pampas Region of Argentina as an introductory part of a breeding programme at INTA. The final aim of this programme is to provide new varieties of annual ryegrass adapted to different management systems

Automated motion analysis of bony joint structures from dynamic computer tomography images: A multi-atlas approach

Dynamic computer tomography (CT) is an emerging modality to analyze in-vivo joint kinematics at the bone level, but it requires manual bone segmentation and, in some instances, landmark identification. The objective of this study is to present an automated workflow for the assessment of three-dimensional in vivo joint kinematics from dynamic musculoskeletal CT images. The proposed method relies on a multi-atlas, multi-label segmentation and landmark propagation framework to extract bony structures and detect anatomical landmarks on the CT dataset. The segmented structures serve as regions of interest for the subsequent motion estimation across the dynamic sequence. The landmarks are propagated across the dynamic sequence for the construction of bone embedded reference frames from which kinematic parameters are estimated. We applied our workflow on dynamic CT images obtained from 15 healthy subjects on two different joints: thumb base (n = 5) and knee (n = 10). The proposed method resulted in segmentation accuracies of 0.90 ± 0.01 for the thumb dataset and 0.94 ± 0.02 for the knee as measured by the Dice score coefficient. In terms of motion estimation, mean differences in cardan angles between the automated algorithm and manual segmentation, and landmark identification performed by an expert were below 1◦. Intraclass correlation (ICC) between cardan angles from the algorithm and results from expert manual landmarks ranged from 0.72 to 0.99 for all joints across all axes. The proposed automated method resulted in reproducible and reliable measurements, enabling the assessment of joint kinematics using 4DCT in clinical routine

Reaction rate reconstruction from biomass concentration measurement in bioreactors using modified second-order sliding mode algorithms

This paper deals with the estimation of unknown signals in bioreactors using sliding observers. Particular attention is drawn to estimate the specific growth rate of microorganisms from measurement of biomass concentration. In a recent article, notions of high-order sliding modes have been used to derive a growth rate observer for batch processes. In this paper we generalize and refine these preliminary results. We develop a new observer with a different error structure to cope with other types of processes. Furthermore, we show that these observers are equivalent, under coordinate transformations and time scaling, to the classical super-twisting differentiator algorithm, thus inheriting all its distinctive features. The new observers' family achieves convergence to time-varying unknown signals in finite time, and presents the best attainable estimation error order in the presence of noise. In addition, the observers are robust to modeling and parameter uncertainties since they are based on minimal assumptions on bioprocess dynamics. In addition, they have interesting applications in fault detection and monitoring. The observers performance in batch, fed-batch and continuous bioreactors is assessed by experimental data obtained from the fermentation of Saccharomyces Cerevisiae on glucose.Facultad de IngenieríaInstituto de Investigaciones en Electrónica, Control y Procesamiento de Señale

3D Spin Glass and 2D Ferromagnetic XY Model: a Comparison

We compare the probability distributions and Binder cumulants of the overlap in the 3D Ising spin glass with those of the magnetization in the ferromagnetic 2D XY model. We analyze similarities and differences. Evidence for the existence of a phase transition in the spin glass model is obtained thanks to the crossing of the Binder cumulant. We show that the behavior of the XY model is fully compatible with the Kosterlitz-Thouless scenario. Finite size effects have to be dealt with by using great care in order to discern among two very different physical pictures that can look very similar if analyzed without large attention.Comment: 14 pages and 6 figures. Also available at http://chimera.roma1.infn.it/index_papers_complex.htm

Numerical Evidence for Spontaneously Broken Replica Symmetry in 3D Spin Glasses

By numerical simulations of the $3d$ Ising spin glass we find evidence that spontaneous replica symmetry breaking theory and not the droplet model describes with good accuracy the equilibrium behavior of the system.Comment: PHYSREV format, 2 .ps figures added with figure command in uufiles forma

Efectos de la reducción de la densidad de siembra en soja

La densidad óptima está sujeta a las condiciones ambientales y edáficas de cada zona. La variación de la cantidad de plantas afecta la capacidad de crecimiento individual debido la competencia en la línea de siembra. Sin embargo, el efecto en el rendimiento no es lineal, dado que los cambios en la disponibilidad de recursos estimulan mecanismos de compensación. En el caso de la Provincia de Entre Ríos la presencia de suelos vertisoles con elevado contenido de arcillas restringe el crecimiento de los cultivos. Con el objetivo de determinar la posibilidad de lograr altos rendimientos con densidades de siembra inferiores a las utilizadas en los planteos agrícolas actuales y determinar los mecanismos de compensación, se realizaron 4 ensayos durante 2013-2016 en lotes con suelos de textura arcillosa donde se utilizaron cultivares de grupo de madurez V y VI con densidades de 3 a 40 plantas m-2. Las menores densidades de 10 y 15 plantas m-2 presentaron diferencias en la intercepción de radiación en el inicio de llenado de granos. Se hallaron diferencias en el número de granos entre las densidades. Sin embargo, este componente presentó poca variación con una disminución del 15-32% al reducir en 61-80% el stand de plantas. El número de granos fue el componente que explicó las diferencias de rendimiento; A bajas densidades se observó mayor generación de nudos en las ramificaciones y además una mayor capacidad de fijar granos por planta. El peso de granos no fue afectado por la variación en la densidad. Esto permitió determinar que en estos cultivares de GM VI el rendimiento relativo del 95% se logra con densidades de 15-20 pl m-2. En los cultivares de GM V este umbral se encontraría en las 25 pl m-2, donde por debajo de este número de plantas el rendimiento se deprime

On Smooth Orthogonal and Octilinear Drawings: Relations, Complexity and Kandinsky Drawings

We study two variants of the well-known orthogonal drawing model: (i) the smooth orthogonal, and (ii) the octilinear. Both models form an extension of the orthogonal, by supporting one additional type of edge segments (circular arcs and diagonal segments, respectively). For planar graphs of max-degree 4, we analyze relationships between the graph classes that can be drawn bendless in the two models and we also prove NP-hardness for a restricted version of the bendless drawing problem for both models. For planar graphs of higher degree, we present an algorithm that produces bi-monotone smooth orthogonal drawings with at most two segments per edge, which also guarantees a linear number of edges with exactly one segment.Comment: Appears in the Proceedings of the 25th International Symposium on Graph Drawing and Network Visualization (GD 2017

Low T Dynamical Properties of Spin Glasses Smoothly Extrapolate to T=0

We compare ground state properties of 3D Ising Spin Glasses with Gaussian couplings with results from off-equilibrium numerical simulations at non zero (but low) temperatures. We find that the non-zero temperature properties of the system smoothly connect to the T=0 behavior, confirming the point of view that results established at T=0 typically also give relevant information about the $T\ne 0$ physics of the system.Comment: 14 pages and 4 ps figure

Pixel and Voxel Representations of Graphs

We study contact representations for graphs, which we call pixel representations in 2D and voxel representations in 3D. Our representations are based on the unit square grid whose cells we call pixels in 2D and voxels in 3D. Two pixels are adjacent if they share an edge, two voxels if they share a face. We call a connected set of pixels or voxels a blob. Given a graph, we represent its vertices by disjoint blobs such that two blobs contain adjacent pixels or voxels if and only if the corresponding vertices are adjacent. We are interested in the size of a representation, which is the number of pixels or voxels it consists of. We first show that finding minimum-size representations is NP-complete. Then, we bound representation sizes needed for certain graph classes. In 2D, we show that, for $k$-outerplanar graphs with $n$ vertices, $\Theta(kn)$ pixels are always sufficient and sometimes necessary. In particular, outerplanar graphs can be represented with a linear number of pixels, whereas general planar graphs sometimes need a quadratic number. In 3D, $\Theta(n^2)$ voxels are always sufficient and sometimes necessary for any $n$-vertex graph. We improve this bound to $\Theta(n\cdot \tau)$ for graphs of treewidth $\tau$ and to $O((g+1)^2n\log^2n)$ for graphs of genus $g$. In particular, planar graphs admit representations with $O(n\log^2n)$ voxels