Random regression models using Legendre polynomials or linear splines for test-day milk yield of dairy Gyr (Bos indicus) cattle

Studies investigating the use of random regression models for genetic evaluation of milk production in Zebu cattle are scarce. In this study, 59,744 test-day milk yield records from 7,810 first lactations of purebred dairy Gyr (Bos indicus) and crossbred (dairy Gyr × Holstein) cows were used to compare random regression models in which additive genetic and permanent environmental effects were modeled using orthogonal Legendre polynomials or linear spline functions. Residual variances were modeled considering 1, 5, or 10 classes of days in milk. Five classes fitted the changes in residual variances over the lactation adequately and were used for model comparison. The model that fitted linear spline functions with 6 knots provided the lowest sum of residual variances across lactation. On the other hand, according to the deviance information criterion (DIC) and Bayesian information criterion (BIC), a model using third-order and fourth-order Legendre polynomials for additive genetic and permanent environmental effects, respectively, provided the best fit. However, the high rank correlation (0.998) between this model and that applying third-order Legendre polynomials for additive genetic and permanent environmental effects, indicates that, in practice, the same bulls would be selected by both models. The last model, which is less parameterized, is a parsimonious option for fitting dairy Gyr breed test-day milk yield records. © 2013 American Dairy Science Association.

Antecedentes para la participación de los países latinoamericanos en el Vigesimocuarto Período de Sesiones de la Comisión de Estadística de Naciones Unidas = Background information for the participation of Latin American countries in the Twenty-fourth Session of the United Nations Statistical Commission

Describe la agenda de la proxima reunion, comenta temas de esa agenda en los que hay programas previstos o en ejecucion, y enumera elementos del programa de trabajo de la Oficina de Estadistica de las NU sobre los cuales la Comision debe tomar decisiones.

Estimates of genetic parameters and eigenvector indices for milk production of Holstein cows

The objectives of the present study were to estimate genetic parameters of monthly test-day milk yield (TDMY) of the first lactation of Brazilian Holstein cows using random regression (RR), and to compare the genetic gains for milk production and persistency, derived from RR models, using eigenvector indices and selection indices that did not consider eigenvectors. The data set contained monthly TDMY of 3,543 first lactations of Brazilian Holstein cows calving between 1994 and 2011. The RR model included the fixed effect of the contemporary group (herd-month-year of test days), the covariate calving age (linear and quadratic effects), and a fourth-order regression on Legendre orthogonal polynomials of days in milk (DIM) to model the population-based mean curve. Additive genetic and nongenetic animal effects were fit as RR with 4 classes of residual variance random effect. Eigenvector indices based on the additive genetic RR covariance matrix were used to evaluate the genetic gains of milk yield and persistency compared with the traditional selection index (selection index based on breeding values of milk yield until 305 DIM). The heritability estimates for monthly TDMY ranged from 0.12 ± 0.04 to 0.31 ± 0.04. The estimates of additive genetic and nongenetic animal effects correlation were close to 1 at adjacent monthly TDMY, with a tendency to diminish as the time between DIM classes increased. The first eigenvector was related to the increase of the genetic response of the milk yield and the second eigenvector was related to the increase of the genetic gains of the persistency but it contributed to decrease the genetic gains for total milk yield. Therefore, using this eigenvector to improve persistency will not contribute to change the shape of genetic curve pattern. If the breeding goal is to improve milk production and persistency, complete sequential eigenvector indices (selection indices composite with all eigenvectors) could be used with higher economic values for persistency. However, if the breeding goal is to improve only milk yield, the traditional selection index is indicated. © 2013 American Dairy Science Association.

Fourth Meeting of the Expert Group on Poverty Statistics, Rio Group

Incluye Bibliografía

Limit Cycles for a Class of Continuous and Discontinuous Cubic Polynomial Differential Systems

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Limit cycles of cubic polynomial differential systems with rational first integrals of degree 2

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dirac gaugions, R symmetry and the 125 GeV Higgs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

STABLE PIECEWISE POLYNOMIAL VECTOR FIELDS

Let N = {y > 0} and S = {y < 0} be the semi-planes of R-2 having as common boundary the line D = {y = 0}. Let X and Y be polynomial vector fields defined in N and S, respectively, leading to a discontinuous piecewise polynomial vector field Z = (X, Y). This work pursues the stability and the transition analysis of solutions of Z between N and S, started by Filippov (1988) and Kozlova (1984) and reformulated by Sotomayor-Teixeira (1995) in terms of the regularization method. This method consists in analyzing a one parameter family of continuous vector fields Z(epsilon), defined by averaging X and Y. This family approaches Z when the parameter goes to zero. The results of Sotomayor-Teixeira and Sotomayor-Machado (2002) providing conditions on (X, Y) for the regularized vector fields to be structurally stable on planar compact connected regions are extended to discontinuous piecewise polynomial vector fields on R-2. Pertinent genericity results for vector fields satisfying the above stability conditions are also extended to the present case. A procedure for the study of discontinuous piecewise vector fields at infinity through a compactification is proposed here.

Modeling random corrosion processes via polynomial chaos expansion

Polynomial Chaos Expansion (PCE) is widely recognized as a flexible tool to represent different types of random variables/processes. However, applications to real, experimental data are still limited. In this article, PCE is used to represent the random time-evolution of metal corrosion growth in marine environments. The PCE coefficients are determined in order to represent data of 45 corrosion coupons tested by Jeffrey and Melchers (2001) at Taylors Beach, Australia. Accuracy of the representation and possibilities for model extrapolation are considered in the study. Results show that reasonably accurate smooth representations of the corrosion process can be obtained. The representation is not better because a smooth model is used to represent non-smooth corrosion data. Random corrosion leads to time-variant reliability problems, due to resistance degradation over time. Time variant reliability problems are not trivial to solve, especially under random process loading. Two example problems are solved herein, showing how the developed PCE representations can be employed in reliability analysis of structures subject to marine corrosion. Monte Carlo Simulation is used to solve the resulting time-variant reliability problems. However, an accurate and more computationally efficient solution is also presented.

A graded subring of an inverse limit of polynomial rings

We study the power series ring R= K[[x1,x2,x3,...]]on countably infinitely many variables, over a field K, and two particular K-subalgebras of it: the ring S, which is isomorphic to an inverse limit of the polynomial rings in finitely many variables over K, and the ring R', which is the largest graded subalgebra of R. Of particular interest are the homogeneous, finitely generated ideals in R', among them the generic ideals. The definition of S as an inverse limit yields a set of truncation homomorphisms from S to K[x1,...,xn] which restrict to R'. We have that the truncation of a generic I in R' is a generic ideal in K[x1,...,xn]. It is shown in Initial ideals of Truncated Homogeneous Ideals that the initial ideal of such an ideal converge to the initial ideal of the corresponding ideal in R'. This initial ideal need no longer be finitely generated, but it is always locally finitely generated: this is proved in Gröbner Bases in R'. We show in Reverse lexicographic initial ideals of generic ideals are finitely generated that the initial ideal of a generic ideal in R' is finitely generated. This contrast to the lexicographic term order. If I in R' is a homogeneous, locally finitely generated ideal, and if we write the Hilbert series of the truncated algebras K[x1,...,xn] module the truncation of I as qn(t)/(1-t)n, then we show in Generalized Hilbert Numerators that the qn's converge to a power series in t which we call the generalized Hilbert numerator of the algebra R'/I. In Gröbner bases for non-homogeneous ideals in R' we show that the calculations of Gröbner bases and initial ideals in R' can be done also for some non-homogeneous ideals, namely those which have an associated homogeneous ideal which is locally finitely generated. The fact that S is an inverse limit of polynomial rings, which are naturally endowed with the discrete topology, provides S with a topology which makes it into a complete Hausdorff topological ring. The ring R', with the subspace topology, is dense in R, and the latter ring is the Cauchy completion of the former. In Topological properties of R' we show that with respect to this topology, locally finitely generated ideals in R'are closed.

Traduzione tecnica e internazionalizzazione d'impresa: Il caso di Technologica S.r.l.

This dissertation is part of the Language Toolkit project which is a collaboration between the School of Foreign Languages and Literature, Interpreting and Translation of the University of Bologna, Forlì campus, and the Chamber of Commerce of Forlì-Cesena. This project aims to create an exchange between translation students and companies who want to pursue a process of internationalization. The purpose of this dissertation is demonstrating the benefits that translation systems can bring to businesses. In particular, it consists of the translation into English of documents supplied by the Italian company Technologica S.r.l. and the creation of linguistic resources that can be integrated into computer-assisted translation (CAT) software, in order to optimize the translation process. The latter is claimed to be a priority with respect to the actual translation products (the target texts), since the analysis conducted on the source texts highlighted that the company could streamline and optimize its English language communication thanks to the use of open source CAT tools such as OmegaT. The work consists of five chapters. The first introduces the Language Toolkit project, the company (Technologica S.r.l ) and its products. The second chapter provides some considerations about technical translation, its features and some misconceptions about it. The difference between technical translation and scientific translation is then clarified and an overview is offered of translation aids such as those used for computer-assisted translation, machine translation, termbases and translation memories. The third chapter contains the analysis of the texts commissioned by Technologica S.r.l. and their categorization. The fourth chapter describes the translation process, with particular attention to terminology extraction and the creation of a bilingual glossary based on a specialized corpus. The glossary was integrated into the OmegaT software in order to facilitate the translation process both for the present task and for future applications. The memory deriving from the translation represents a sort of hybrid resource between a translation memory and a glossary. This was found to be the most appropriate format, given the specific nature of the texts to be translated. Finally, in chapter five conclusions are offered about the importance of language training within a company environment, the potentialities of translation aids and the benefits that they would bring to a company wishing to internationalize itself.

Tradurre per le imprese. Analisi e traduzione in inglese della Nota integrativa al Bilancio consolidato 2013 di MNLG S.r.l.-Holding Sorma Group

The aim of this dissertation is to provide a translation in English of the Notes on the Consolidated Financial Statements of MNLG S.r.l., holding company of the Italian Sorma Group. This translation work is one example of the technical material produced in accordance with the project called Language Toolkit, set up by the Chamber of Commerce of Forlì-Cesena, to support the internationalization of the companies established in the territory. This initiative has represented a unique opportunity for me to put into practice the knowledge and abilities learnt in the translation field during these years at university. It also allowed me to give a concrete purpose to my dissertation, that is to provide a technical document translated into a foreign language. By making its Consolidated Financial Statement readily available in English, the company MNLG S.r.l. can in fact increase the number of possible investors and guarantee a more transparent financial informative to its shareholders. This translation work is divided into six chapters: the first one describes the project, its main objectives and the ways in which it was developed. The second chapter deals with the notions of Consolidated Financial Statements and presents the accounting documents of which the Financial Statements are made up as well as the norms according to which they are prepared. The third chapter, instead, focuses on the translation procedure applied and especially on the documentation process, analysing the differences between the International Accounting Standards and the accounting standards used in Italy. The fourth chapter provides a description of the translation resources built for the translation of this specific document. The fifth chapter includes the English version of the Notes on the Consolidated Financial Statements and, to conclude, the sixth chapter analyses the difficulties encountered in translating and the strategies adopted to overcome them.

Efficient computation of discrete polynomial transforms

This letter presents a new recursive method for computing discrete polynomial transforms. The method is shown for forward and inverse transforms of the Hermite, binomial, and Laguerre transforms. The recursive flow diagrams require only 2 additions, 2( +1) memory units, and +1multipliers for the +1-point Hermite and binomial transforms. The recursive flow diagram for the +1-point Laguerre transform requires 2 additions, 2( +1) memory units, and 2( +1) multipliers. The transform computation time for all of these transforms is ( )