Efficiency of augmented designs for selection

Each of two populations of 529 F(,3)-derived lines of oats (Avena sativa L.) in the F(,5\u27) one (W2) developed by interspecific (A. sativa(\u273) x A. sterilis) hydridization and the other (C2) developed by cultivar hybridization, and five oat cultivars used as check entries, were tested in each of four environments in Iowa. They were evaluated in an augmented randomized complete block (ARCBD), a randomized complete block (RCBD), and a simple lattice design (LD) with a field arrangement such that one set of plots in a replication accommodated all three designs. Each of two replications for a population tested in an environment also was used as the basis for studying the efficiency of three unreplicated experimental designs for plant breeding. These were the NOADJ, in which unadjusted phenotypic values for grain yield (GYLD) were used to judge the worth of the oat lines, and the ARCBD and NOCH unreplicated designs in which the phenotypic value of a line was adjusted by subtracting the corresponding block effect estimated from check and entry means, respectively;To compare the efficiencies of the unreplicated and replicated experimental designs for selection for GYLD, the genotypic yielding abilities of the lines were evaluated by calculating means (called genotypic values) for GYLD from data collected from these lines in previous experiments;Among the replicated experimental designs, LD was the most efficient for controlling intra-site error variance and ARCBD was the least efficient. This superiority of LD, however, was not very great, and there was little difference among the replicated designs when efficiency of selection for GYLD was the judgment criterion. The use of experimental designs, either unreplicated or replicated, that used plot yield adjustments, in general, was not better for selection than were NOADJ or RCBD, respectively, neither of which entailed plot adjustment. All replicated and unreplicated designs were successful for selection according to every criterion used, but making a choice among either unreplicated or among replicated designs for efficiency for selection was relatively unimportant. All criteria used to evaluate replicated and unreplicated designs indicated that success from selection was highly dependent upon the genetic material being used

Inbreeding and yield of synthetic varieties derived from single and double cross hybrids

Maize (Zea mays L) seed saving among producers in low-income and lesser in developed countries is often prac-ticed. In México, advanced generations of maize hybrids and even mixtures of single-cross (SCs) and double-cross hybrids (DCs) are grown. These populations are expected to perform similar to the synthetic varieties (SVs) . srenibmocd ooge ra, ylbamuserp, tahts dirbyhe htf on oitavirede htn id evlovnis enile htm orfd evirede bd luoct ahtThe derivation of SVs from hybrids seems attractive because would be easier because of the reduced number of potential parents. The frequencies of the genes of the SCs, however, may differ from those of the DCs, may affect the inbreeding coefficient, and thereby the genotypic mean. To address these and related issues, this study was conducted to derive formulae to calculate the inbreeding coefficient (IC) and to predict the genotypic mean (GM) of SVs derived from a mixture of s SCs and d DCs, each represented by m individuals. Formulae for its IC (FSynSC,DC) and GM (YSynSC,DC) were derived. For hybrid parents derived from fully inbred and unrelated lines, FSynSC,DC = [2ms+d(m+1)]/[4m(s+d)2] and, independently of the type of lines, YSynSC,DC = YPS/(s+d)+YPC(s+d−1)/(s+d), where YPS is the genotypic mean of the s + d populations that result from randomly mating the m individuals of each par-ent, and YPC is the mean of all crosses between the s + d parents. From eight lines, three sets of parents (each set involved all eight lines) were considered: 1) four SCs (4SC), 2) two SCs and one DC (2SC+DC), and 3) two DCs (2DC). The SV produced by 4SC shows the lowest IC, although for large m (m > 10) the IC of the SV produced by 2DC is about equal. The largest IC, and thereby the smallest GM, is associated to 2SC+DC because the coances-try between individuals and gene frequencies in SCs are twice those of DCs. What is more noticeable, however, is that 2DC produces the cheapest way of deriving and predicting a SV since only three entries are required (two parents and their cross) and with large m the IC is about the minimum

Synthesis of Acetylhomoagmatine

The first total synthesis of acetylhomoagmatine, a natural product isolated form the methanolic extracts from the sponge Cliona celata, is performed in four steps in a very high yield.Galicia. Consellería de Innovación, Industria e Comercio; PGIDIT05RMA10302PRColombia.Colciencias; 1101-09-1354

Virus de Zika, otro dolor de cabeza para la salud pública

Articulo de Intere

Matriz de coeficientes para la ecuación diferencial de Chauchy-Euler

In this article application and advance is given to the method that allows to find in a simple way the constant coefficients that are required in the solution of a differential equation with the structure of Cauchy-Euler, presented and made known in [1]. Here we will see the construction form of the characteristic polynomials, using the aforementioned method as a basis; with a series of equations, matrices and novel methods to solve this type of ODEs and, above all, very practical for the equation of a much higher order. The idea is to present a structure or methodology in matrix form that allows to solve in a practical way differential equation of higher order with Cauchy-Euler structure.En este artículo, se muestra una aplicación y avance al método que permite encontrar de manera simple los coeficientes constantes que se requieren en la solución de una ecuación diferencial con la estructura de Cauchy-Euler, presentada y dada a conocer en [1]. Aquí veremos la forma de construcción de los polinomios característicos, utilizando el método mencionado anteriormente como base; con una serie de ecuaciones, matrices y métodos novedosos para resolver este tipo de EDO y, sobre todo, muy prácticas para la solución de la ecuación de orden superior. La idea es presentar una estructura o metodología en forma matricial que permita resolver de manera práctica la ecuación diferencial de orden superior con la estructura de Cauchy-Euler

An analogue to the pion decay constant in the multi-flavor Schwinger model

We study the Schwinger model with $N_{\rm f} \geq 2$ degenerate fermion flavors, by means of lattice simulations. We use dynamical Wilson fermions for $N_{\rm f} = 2$, and re-weighted quenched configurations for overlap-hypercube fermions with $N_{\rm f} \leq 6$. In this framework, we explore an analogue of the QCD pion decay constant $F_{\pi}$, which is dimensionless in $d=2$, and which has hardly been considered in the literature. We determine $F_{\pi}$ by three independent methods, with numerical and analytical ingredients. First, we consider the 2-dimensional version of the Gell-Mann--Oakes--Renner relation, where we insert both theoretical and numerical values for the quantities involved. Next we refer to the $\delta$-regime, {\it i.e.\ a small spatial volume, where we assume formulae from Chiral Perturbation Theory to apply even in the absence of Nambu-Goldstone bosons. We further postulate an effective relation between $N_{\rm f}$ and the number of relevant, light bosons, which we denote as "pions". Thus $F_{\pi}$ is obtained from the residual "pion" mass in the chiral limit, which is a finite-size effect. Finally, we address to the 2-dimensional Witten--Veneziano formula: it yields a value for $F_{\eta}$, which we identify with $F_{\pi}$, as in large-$N_{\rm c}$ QCD. All three approaches consistently lead to $F_{\pi} \simeq 1/\sqrt{2 \pi}$ at fermion mass $m=0$, which implies that this quantity is meaningful.Comment: 25 pages, LaTex, 11 figures, final version to appear in Phys. Rev.