Quasiconvex Constrained Multicriteria Continuous Location Problems: Structure of Nondominated Solution Sets

In this paper, we consider constrained multicriteria continuous location problems in two-dimensional spaces. In the literature, the continuous multicriteria location problem in two-dimensional spaces has received special attention in the last years, although only particular instances of convex functions have been considered. Our approach only requires the functions to be strictly quasiconvex and inf-compact. We obtain a geometrical description that provides a unified approach to handle multicriteria location models in two-dimensional spaces which has been implemented in MATHEMATIC

Efecto del Locus CSN3 sobre la composición de la leche de cabra de raza murciano-granadina

CICYT AGL2002-04304-C03-01-02- 03 GA

Estructuras de fábrica: enfoques «antiguos» y «modernos» para fenómenos muy locales

The characterization of the material as a discontinuous media is proposed to study strongly local phenomena in the behaviour of historical masonry structures. Three methods are implemented: an experimental method, photoelastic, and two numerical methods, heterogeneous finite elements and rigid blocks in unilateral contact. Qualitative comparison of the results shows that the random irregularities in the contact between bodies play an important role in explaining local behaviour of masonry. Quantitative comparison with the results of load tests previously performed on dry masonry walls support this hypothesis. The results are very encouraging and suggest that it is necessary to develop approaches of this kind –approaches that, although relatively common in the field of granular media, have been very scarce in the field of historic masonry structures.Para estudiar ciertos fenómenos de comportamiento local en las estructuras históricas de fábrica se propone la caracterización del material como un medio discontinuo. Se implementan tres métodos: uno experimental, fotoelástico, y dos numéricos, elementos finitos heterogéneos y bloques rígidos en contacto unilateral. De la comparación cualitativa de los resultados se deduce que las irregularidades aleatorias en el contacto entre piezas desempeñan un importante papel en la explicación del comportamiento local de la fábrica. La comparación cuantitativa con los resultados de ensayos de carga realizados previamente sobre muros aparejados en seco apoyan esta hipótesis. Los resultados obtenidos son muy esperanzadores y hacen pensar que es necesario profundizar en el desarrollo de enfoques de este tipo que, aún siendo relativamente comunes en el campo de los medios granulares, han sido muy escasos en el campo de las estructuras históricas de fábrica

Neomudejar Architecture and Analysis of Local Stresses of Masonry Structures: The Escuelas Aguirre Case Study

At the end of the 19th century, an architectural style called Neomudéjar became quite popular in some areas of Spain. Very much like other historicist European styles in the same years, the Neomudéjar sought to recreate the local medieval architecture. The use of faced brick façades with complicated bonds -formed by stretchers and headers in and out the main wall plane- lead in term to a wide variety of results that resembled Arabic architecture. The brick façades of the Neomudéjar buildings are ideal case studies for the analysis of the local behaviour of masonry structures, especially regarding problems of stress concentration. There are several methods for studying the global behaviour of masonry structures – from the classic thrust line to the limit analysis tools – but, as the average stresses taken over by structural masonry elements are usually well below the compression strength of the constituent material, the classical methods of analysis are designed to verify only the global stability. Local behaviour, on the other hand, is quite elusive, especially when the properties of the material are uncertain. In such cases stress concentrations might appear, resulting on stress currents and low stress islets. A particular case of these phenomena occurs in the bonding of Neomudéjar façades. Local concentration of stresses is especially likely in these bonds, given the peculiar relative position of some bricks with respect to others. The paper proposed will use one of these buildings, the Aguirre Schools (Rodríguez Ayuso, Madrid, 1886), as a case study to evaluate local behaviour. Starting from a geometrical hypothesis of the internal distribution of the material based on recent photogrammetric surveys, and using conventional software of parametric design, the paper will describe a numerical model based on a non-deterministic random algorithm, although limited in its number of solutions, to discuss later the validity and scope of them. The limitations of the standard hardware in which these design tools are usually handled will also be considered in the discussion

Short communication: An association analysis between one missense polymorphism at the SREBF1 gene and milk yield and composition traits in goats

Sterol regulatory element binding transcription factor 1 (SREBF1) regulates the expression of genes involved in the biosynthesis of fatty acids and cholesterol. Herewith, we have sequenced the near-complete coding region and part of the 3?UTR of the goat SREBF1 gene. In doing so, we have detected a missense c.353CT polymorphism causing a proline to leucine substitution at position 118 (P118L). An association analysis with milk composition traits recorded in MurcianoGranadina goats only revealed a statistical tendency linking SREBF1 genotype and milk omega-3 fatty acid content. The lack of significant associations suggests that the P118L substitution does not involve a functional change.Le facteur de transcription de´nomme´ Sterol regulatory element binding transcription factor 1 (SREBF1) re´gule l’expression des ge`nes implique´s dans la biosynthe`se des acides gras et du choleste´rol. Dans cette e´tude, nous avons se´quence´ la quasi-totalite´ de la re´gion codante et une partie du la re´gion 3?UTR du ge`ne SREBF1 de la che`vre. Ce travail, nous a permis d’identifier un polymorphisme non-synonyme c.353CT causant la substitution d’une Proline en Leucine a` la position 118. L’e´tude d’association avec la composition du lait enregistre´e en che`vres Murciano-Granadina, a re´ve´le´ seulement une tendance statistique reliant SREBF1 ge´notype et l’acide gras ome´ga-3 du lait. L’absence d’associations significatives sugge`re que la substitution P118L n’implique pas un changement fonctionnel

Short communication: Effect of αS1-casein (CSN1S1) and κ-casein (CSN3) genotypes on milk composition in Murciano-Granadina goats

The effects of the caprine alpha(S1)-casein (CSN1S1) polymorphisms on milk quality have been widely demonstrated. However, much less is known about the consequences of the kappa-casein (CSN3) genotype on milk composition in goats. Moreover, the occurrence of interactions between CSN3 and CSN1S1 genotypes has not been investigated. In this study, an association analysis between CSN1S1 and CSN3 genotypes and milk quality traits was performed in 89 Murciano-Granadina goats. Total milk yield as well as total protein, fat, solids-not-fat, lactose, alpha(S1)-casein (CSN1S1), and alpha(S2)-casein (CSN1S2) contents were recorded every other month during a whole lactation (316 observations). Data analysis using a linear mixed model for repeated observations revealed no interaction between the CSN1S1 and CSN3 genotypes. With regard to the effect of the CSN3 locus, AB and BB genotypes were significantly associated with higher levels of total casein and protein content compared with the AA CSN3 genotype. In strong contrast with French breeds, the CSN1S1 genotype did not affect protein, casein, and fat concentrations in Murciano-Granadina goats. These results highlight the importance of taking into consideration the CSN3 genotype when performing selection for milk composition in dairy goats

Dimensionality Reduction for Classification: Comparison of Techniques and Dimension Choice

We investigate the effects of dimensionality reduction using different techniques and different dimensions on six two-class data sets with numerical attributes as pre-processing for two classification algorithms. Besides reducing the dimensionality with the use of principal components and linear discriminants, we also introduce four new techniques. After this dimensionality reduction two algorithms are applied. The first algorithm takes advantage of the reduced dimensionality itself while the second one directly exploits the dimensional ranking. We observe that neither a single superior dimensionality reduction technique nor a straightforward way to select the optimal dimension can be identified. On the other hand we show that a good choice of technique and dimension can have a major impact on the classification power, generating classifiers that can rival industry standards. We conclude that dimensionality reduction should not only be used for visualisation or as pre-processing on very high dimensional data, but also as a general preprocessing technique on numerical data to raise the classification power. The difficult choice of both the dimensionality reduction technique and the reduced dimension however, should be directly based on the effects on the classification power