The Effect of Hay Supplementation on Performance of Grazing Alpaca in the Peruvian Andes

Productivity of alpaca grazing rangelands in the Andes is often limited by the low availability and quality of those pastures during the dry season of the year. The use as supplements of forages cultivated during the rainy season in appropriate areas in the Andes may be a strategy to improve performance of alpacas. Therefore, the supplementation of oat-vetch pellets or oat hay was evaluated and compared with a control group without supplementation. Sixty three female alpacas (15 months of age, 34 ± 1.0 kg BW), divided in three groups, grazing range pastures (6.1% crude protein and 61.3% NDF) during dry season in Puno region of the Peruvian Andes were used for the study. The supplement was offered daily after grazing (400 g/alpaca/day). The study lasted for 84 days with evaluations of weight gain and intake every 28 days. Weight gain was greater for animals supplemented with oat-vetch pellet (3.1 ± 0.27 kg) compared to oat hay (0.98 ± 0.33) (P≤ 0.05) while the control lost BW (0.64 ± 0.22). The total dry matter intake (pasture and supplement) was 502, 575.6 and 579.5 g / alpaca/ day for the control, oat-vetch pellet and oat hay group respectively indicating partial replacement of pasture by the supplement. Under the study conditions, the supplementation of oat-vetch pellets improved performance better than oats hay or no supplementation for alpacas grazing range pastures during the dry season

SeqBreed : a python tool to evaluate genomic prediction in complex scenarios

Background: Genomic prediction (GP) is a method whereby DNA polymorphism information is used to predict breeding values for complex traits. Although GP can significantly enhance predictive accuracy, it can be expensive and difficult to implement. To help design optimum breeding programs and experiments, including genome-wide association studies and genomic selection experiments, we have developed SeqBreed, a generic and flexible forward simulator programmed in python3. Results: SeqBreed accommodates sex and mitochondrion chromosomes as well as autopolyploidy. It can simulate any number of complex phenotypes that are determined by any number of causal loci. SeqBreed implements several GP methods, including genomic best linear unbiased prediction (GBLUP), single-step GBLUP, pedigree-based BLUP, and mass selection. We illustrate its functionality with Drosophila genome reference panel (DGRP) sequence data and with tetraploid potato genotype data. Conclusions: SeqBreed is a flexible and easy to use tool that can be used to optimize GP or genome-wide association studies. It incorporates some of the most popular GP methods and includes several visualization tools. Code is open and can be freely modified. Software, documentation, and examples are available at https://github.com/miguelperezenciso/SeqBreed

Quantitative trait locus analysis of hybrid pedigrees: variance-components model, inbreeding parameter, and power

<p>Abstract</p> <p>Background</p> <p>For the last years reliable mapping of quantitative trait loci (QTLs) has become feasible through linkage analysis based on the variance-components method. There are now many approaches to the QTL analysis of various types of crosses within one population (breed) as well as crosses between divergent populations (breeds). However, to analyse a complex pedigree with dominance and inbreeding, when the pedigree's founders have an inter-population (hybrid) origin, it is necessary to develop a high-powered method taking into account these features of the pedigree.</p> <p>Results</p> <p>We offer a universal approach to QTL analysis of complex pedigrees descended from crosses between outbred parental lines with different QTL allele frequencies. This approach improves the established variance-components method due to the consideration of the genetic effect conditioned by inter-population origin and inbreeding of individuals. To estimate model parameters, namely additive and dominant effects, and the allelic frequencies of the QTL analysed, and also to define the QTL positions on a chromosome with respect to genotyped markers, we used the maximum-likelihood method. To detect linkage between the QTL and the markers we propose statistics with a non-central χ²-distribution that provides the possibility to deduce analytical expressions for the power of the method and therefore, to estimate the pedigree's size required for 80% power. The method works for arbitrarily structured pedigrees with dominance and inbreeding.</p> <p>Conclusion</p> <p>Our method uses the phenotypic values and the marker information for each individual of the pedigree under observation as initial data and can be valuable for fine mapping purposes. The power of the method is increased if the QTL effects conditioned by inter-population origin and inbreeding are enhanced. Several improvements can be developed to take into account fixed factors affecting trait formation, such as age and sex.</p

RALEO DE FRUTOS EN PLANTAS DE MELÓN (Cucumis melo) DEL TIPO RETICULADO CULTIVADO EN INVERNADERO

El raleo de frutos es una práctica utilizada en horticultura para aumentar el tamaño de frutos. Este trabajo tuvo como objetivo evaluar el rendimiento y calidad de frutos del melón variedad Autumn Waltz, sometido a diferentes intensidades de raleo de frutos. El experimento fue realizado en un invernadero de la Facultad de Ciencias Agrarias, Universidad Nacional de Asunción, ubicado en San Lorenzo, Paraguay, a 25º 20' de latitud Sur y 57º 31' longitud Oeste. La producción de mudas fue en bandejas y el transplante al lugar definitivo se realizó el 22/02/08 y la cosecha entre el 7/05/08 y 29/05/08. El cultivo fue conducido en forma tutorada con dos ramas por planta. Los tratamientos fueron: T1= 1 fruto/rama (2 frutos/planta); T2= 2 frutos/rama (4 frutos/planta); T3 = 3 frutos/rama (6 frutos/planta) y T4= Sin raleo de frutos. El diseño estadístico fue completamente al azar con 5 repeticiones. Los datos fueron sometidos al análisis de varianza y prueba de Duncan al 5%. El tratamiento con 1 fruto/rama generó las mayores medias para peso, diámetro y altura de frutos, mientras para rendimiento por planta, proporcionó la menor media

Qxpak.5: Old mixed model solutions for new genomics problems

Mixed models have a long and fruitful history in statistics. They are pertinent to genomics problems because they are highly versatile, accommodating a wide variety of situations within the same theoretical and algorithmic framework. Qxpak is a package for versatile statistical genomics, specifically designed for sophisticated quantitative trait loci and association analyses. Multiple loci, multiple trait, infinitesimal genetic effects, imprinting, epistasis or sex linked loci can be fitted. The new version (v. 5) allows us, among other new features, to include either relationship matrices obtained with molecular information or user defined matrices that can be read from an input file. This feature can be used for genome selection or - more importantly - to correct for population structure in association studies. In crosses, two parental lines, not necessarily inbred, can be accommodated. This software aims at simplifying statistical genetic analyses implementing a coherent and unified approach by mixed models. It provides a tool that can be used in a wide variety of situations with ample genetic and statistical modeling flexibility. The software, a complete manual and examples are available at http://www.icrea.cat/Web/OtherSectionViewer.aspx?key=485&titol=Software:Qxpak.

CARACTERIZACIÓN MORFOLÓGICA DE COLECTAS Y ACCESIONES DE Jatropha curcas L, EN EL DEPARTAMENTO DE ALTO PARANÁ, PARAGUAY

Esta evaluación se llevó acabo entre los meses de enero y julio del 2009, con el propósito de caracterizar morfológicamente la colección de germoplasma de Jatropha curcas del Centro Tecnológico Agropecuario en Paraguay (CETAPAR). El método empleado para las evaluaciones fue el de muestreo aleatorio con quince tratamientos y cinco repeticiones. La colección se encuentra compuesta de 15 híbridos clonales implantados en el año 2007, provenientes de colectas de las localidades paraguayas de: Guayaki, Juan León Mallorquín, Minga Guazú, Caraguatay, La Colmena, Sapucai, Fulgencio R. Moreno, Santa Rosa del Aguaray y Horqueta; y de la localidad brasileña de Dourados; además de accesiones del estado brasileño de Minas Gerais, cuyas denominaciones son: Bento, Filomena, Gonzalo, Oracilia y Paraguaçu. Se evaluaron la altura de plantas en enero y julio, crecimiento en altura en 6 meses, diámetro de tallo, diámetro de copa, número de ramas primarias y secundarias, diámetro ecuatorial de frutos, longitud y ancho de semillas. Los resultados estadísticos muestran que para las variables: altura de planta y número de ramas por planta existen diferencias entre los materiales, no así para las demás características evaluadas

COMPORTAMIENTO AGRONOMICO DEL MAMON TAINUNG 01 EN FINCA DE PRODUCTOR BAJO LAS CONDICIONES DEL DEPARTAMENTO DE CORDILLERA

Con el objetivo de evaluar el comportamiento agronómico del mamón híbrido Tainung 01 en finca de productor, se condujo un experimento en el período de febrero de 2008 a marzo de 2009, en finca de productor en el municipio de Caacupé, departamento de Cordillera, Paraguay, ubicado aproximadamente a 25º 24' S y 57º 06' O y 228 msnm de altitud. La parcela experimental estuvo constituida por 100 plantas, de las cuales fueron seleccionadas después de la floración 20 plantas con flores hermafroditas para las evaluaciones. El sistema de riego fue por goteo. Los datos obtenidos fueron analizados mediante la estimación de la media poblacional de las variables medidas, con intervalo de confianza del 95 % de confiabilidad. Las medias obtenidas de las variables medidas fueron: altura de inserción del fruto de 0,85 m, diámetro de tallo de 9,54 cm, número de frutos por planta de 20,30; peso de fruto de 728,54 g, productividad por planta de 14,82 kg, longitud de fruto de 20,89 cm, diámetro de fruto de 9,16 cm; rendimiento de 24,69 t/ha y contenido de sólidos solubles totales de 14,21 ºBrix.

A remark on an overdetermined problem in Riemannian Geometry

Let $(M,g)$ be a Riemannian manifold with a distinguished point $O$ and assume that the geodesic distance $d$ from $O$ is an isoparametric function. Let $\Omega\subset M$ be a bounded domain, with $O \in \Omega$, and consider the problem $\Delta_p u = -1$ in $\Omega$ with $u=0$ on $\partial \Omega$, where $\Delta_p$ is the $p$-Laplacian of $g$. We prove that if the normal derivative $\partial_{\nu}u$ of $u$ along the boundary of $\Omega$ is a function of $d$ satisfying suitable conditions, then $\Omega$ must be a geodesic ball. In particular, our result applies to open balls of $\mathbb{R}^n$ equipped with a rotationally symmetric metric of the form $g=dt^2+\rho^2(t)\,g_S$, where $g_S$ is the standard metric of the sphere.Comment: 8 pages. This paper has been written for possible publication in a special volume dedicated to the conference "Geometric Properties for Parabolic and Elliptic PDE's. 4th Italian-Japanese Workshop", organized in Palinuro in May 201

The boson peak in structural and orientational glasses of simple alcohols: Specific heat at low temperatures

We review in this work specific-heat experiments, that we have conducted on different hydrogen-bonded glasses during last years. Specifically, we have measured the low-temperature specific heat Cp for a set of glassy alcohols: normal and fully-deuterated ethanol, 1- and 2- propanol, and glycerol. Ethanol exhibits a very interesting polymorphism presenting three different solid phases at low temperature: a fully-ordered (monoclinic) crystal, an orientationally-disordered (cubic) crystal or 'orientational glass', and the ordinary structural glass. By measuring and comparing the low-temperature specific heat of the three phases, in the 'boson peak' range 2-10 K as well as in the tunneling-states range below 1K, we are able to provide a quantitative confirmation that ''glassy behavior'' is not an exclusive property of amorphous solids. On the other hand, propanol is the simplest monoalcohol with two different stereoisomers (1- and 2-propanol), what allows us to study directly the influence of the spatial rearrangement of atoms on the universal properties of glasses. We have measured the specific heat of both isomers, finding a noteworthy quantitative difference between them. Finally, low-temperature specific-heat data of glassy glycerol have also been obtained. Here we propose a simple method based upon the soft-potential model to analyze low-temperature specific-heat measurements, and we use this method for a quantitative comparison of all these data of glassy alcohols and as a stringent test of several universal correlations and scaling laws suggested in the literature. In particular, we find that the interstitialcy model for the boson peak [A. V. Granato, Phys. Rev. Lett. 68 (1992) 974] gives a very good account of the temperature at which the maximum in Cp/T^3 occurs.Comment: 16 pages, 2 figures, Proceedings of the 4th International Discussion Meeting on Relaxations in Complex Systems, Hersonissos (Crete), June 2001. Journal of Non-Crystalline Solids (accepted for publication

New superintegrable models with position-dependent mass from Bertrand's Theorem on curved spaces

A generalized version of Bertrand's theorem on spherically symmetric curved spaces is presented. This result is based on the classification of (3+1)-dimensional (Lorentzian) Bertrand spacetimes, that gives rise to two families of Hamiltonian systems defined on certain 3-dimensional (Riemannian) spaces. These two systems are shown to be either the Kepler or the oscillator potentials on the corresponding Bertrand spaces, and both of them are maximally superintegrable. Afterwards, the relationship between such Bertrand Hamiltonians and position-dependent mass systems is explicitly established. These results are illustrated through the example of a superintegrable (nonlinear) oscillator on a Bertrand-Darboux space, whose quantization and physical features are also briefly addressed.Comment: 13 pages; based in the contribution to the 28th International Colloquium on Group Theoretical Methods in Physics, Northumbria University (U.K.), 26-30th July 201