Quasipolynomial formulas for the Kronecker coefficients indexed by two two-row shapes (extended abstract)

We show that the Kronecker coefficients indexed by two two–row shapes are given by quadratic quasipolynomial formulas whose domains are the maximal cells of a fan. Simple calculations provide explicitly the quasipolynomial formulas and a description of the associated fan. These new formulas are obtained from analogous formulas for the corresponding reduced Kronecker coefficients and a formula recovering the Kronecker coefficients from the reduced Kronecker coefficients. As an application, we characterize all the Kronecker coefficients indexed by two two-row shapes that are equal to zero. This allowed us to disprove a conjecture of Mulmuley about the behavior of the stretching functions attached to the Kronecker coefficients.Ministerio de Educación y Ciencia MTM2007–64509Junta de Andalucía FQM–33

Nota aclaratoria sobre la designación del Valle de Londres

Fil: Zuluaga, Rosa Mercedes. Universidad Nacional de Cuyo. Facultad de Filosofía y Letra

She-austerity. Precariedad y desigualdad laboral de las mujeres en el sur de Europa

This article presents a comparative and longitudinal analysis of the situation of Spanish, Portuguese and Italian women since the beginning of the crisis. The study follows three specific objectives: expose the female labor market in the three states; analyze women’s labor participation from the perspective of precariousness; and analyze the position of women and men in gender relations from the perspective of gender inequality. The research has been prepared by the technique of documentary analysis of secondary sources of official statistics. We conclude that the crisis has affected women from southern European countries in a similar manner because of their greater compliance with traditional gender roles, but at the same time, some differences between them are observed as a result of the different economic structures, labor legislation and social protection regimes.El artículo presenta un análisis comparativo y longitudinal de la situación de las mujeres en España, Portugal e Italia, desde el inicio de la crisis. Los objetivos específicos son: exponer el mercado laboral femenino en los tres países, examinar la presencia laboral de las mujeres desde la perspectiva de la precariedad y analizar la posición de mujeres y hombres en las relaciones de género desde la perspectiva de la desigualdad de género. La investigación se llevó a cabo mediante la técnica de análisis documental de fuentes secundarias de estadísticas oficiales. Se concluye que la crisis ha afectado a las mujeres de los países europeos del sur de manera similar por su mayor continuidad en el desempeño del rol de género tradicional, pero, a la vez, se observan algunas diferencias entre ellos como consecuencia de las diferentes estructuras económicas, legislaciones laborales y protección social

Analysis of Balmer Profiles of early type stars

The spectral energy distribution (SED) of recent star formation regions is dominated by the more massive and early stars (O and B types). These stars show large and very significant absorption features, the most prominent being the recombination lines of H, HeI and HeII. In particular, the shape of their profiles are very dependent on the luminosity of the star. We have explored the potential use of high resolution profiles to discriminate between different luminosity classes and spectral types, by using profiles of the He and Balmer lines. We have calculated growth curves for each of the lines and their dependence on gravity and effective temperature. We show some of these theoretical growth curves and our preliminary conclusions are analyzed and discussed.Comment: 1 pag, Contribution to the conference "Cosmic Evolution and Galaxy Formation: Structure, Interactions and Feedback", Nov. 1999 (Puebla, Mexico), to be published in ASP. Conf. Series, Eds. J. Franco, E. Terlevich. O. Lopez-Cruz, I. Aretxag

Avaliando a interrupção da conectividade longitudinal em assembleias de macroinvertebrados em um rio semi-árido

Aim: Our aim in this study was evaluate the effects of flow regulation for irrigation on the macroinvertebrate assemblages in a semiarid river. Methods:We sampled two reaches in Dulce River; one placed upstream a weir that diverts flow into a network of irrigation channels and the other downstream that weir, in the assessment of the fluvial discontinuity. We assess the differences among reaches and sites, environmental variables, invertebrate density, richness and Shannon-Wiener index applying non-parametric analyses of variance Kruskal Wallis. The similarity percentage analysis (SIMPER) was used to identify which species contributed to the dissimilarities on macroinvertebrate assemblage structure. Canonical Correspondence Analysis (CCA) was performed with the total set of samples to explore macroinvertebrate distribution in reaches and associations of the assemblages with habitat variables. Results .The density, richness and Shannon index values did not show differences between the reaches located upstream and downstream. Beta diversity (Whittaker) was 0.72 among upstream sites, 0.56 among downstream sites and higher species turnover (0.73) was obtained between both reaches. The Canonical Correspondence Analysis explained 46.71% of the variance differentiating upstream sites explained by higher values of organic matter of bottom sediments and discharge, high density of Nais communis, Bothrioneurum americanum, Pelomus, Stephensoniana trivandrana, Pristina menoni, P. jenkinae, P.longidentata, P. americana, Dero obtusa, Endotribelos, Heleobia and Turbellaria. The downstream sites were associated to coarser substratum and higher density of Lopescladius, Polypedilum, Cricotopus, Thienamaniella, Cryptochironomus, Baetidae, Nematoda and Corbicula fluminea. Conclusions: The low-flow disturbance had effects on the composition of the benthic invertebrate assemblages, but attributes (such as density and richness) showed a lower variability probably because of taxa replacement.Objetivo: Nosso objetivo neste estudo foi avaliar os efeitos da regulação do fluxo de um rio semi-árido utilizado para irrigação sobre as assembleias de macroinvertebrados. Métodos: Nós amostramos duas seções no rio Dulce River, um trecho localizado a montante da barragem de desvio em Los Quiroga e outro a justante, para avaliação da descontinuidade fluvial. Nós avaliamos as diferenças entre os trechos e sítios de amostragem com relação às variáveis ambientais, a densidade de invertebrados, a riqueza e o índice de Shannon aplicando análise de variância não-paramétrica de Kruskal-Wallis. A Análise de Porcentagem de Similaridade (SIMPER) foi usada para identificar quais espécies contribuiram para as dissimilaridades da estrutura das assembleias de macroinvertebrados. A Análise de Correspondência Canônica (CCA) foi executada com o conjunto total de amostras para explorar a distribuição dos macroinvertebrados nos trechos e as associações das assembleias com as variáveis do habitat. Resultados: Os valores da densidade, da riqueza e do índice de Shannon não mostraram diferenças entre os trechos a montante e a jusante da barragem de desvio. A diversidade beta (Whittaker) foi de 0,72 entre os locais à montante, 0,56 entre os locais a justante e a maior taxa de reposição de espécies (0,73) foi obtida ente ambos os trechos. A Análise de Correspondência Canônica explicou 46,71% da variância diferindo os locais a montante explicados pelos altos valores de matéria orgânica do sedimento e descarga, altas densidades de Nais communis, Bothrioneurum americanum, Pelomus, Stephensoniana trivandrana, Pristina menoni, P. jenkinae, P.longidentata, P. americana, Dero obtusa, Endotribelos, Heleobia e Turbellaria. Os sítios de amostragem a jusante estiveram associadas a substrato mais grosseiro e densidade maior de Lopescladius, Polypedilum, Cricotopus, Thienamaniella, Cryptochironomus, Baetidae, Nematoda e Corbicula fluminea. Conclusão: O distúrbio de baixo fluxo teve efeitos sobre a composição das assembleias de invertebrados bentônicos, mas também atributos (tais como densidade e riqueza) apresentaram menor variabilidade provavelmente devido à reposição de táxons.Fil: Leiva, Marta Elisabeth. Universidad Nacional de Santiago del Estero. Facultad de Cs.forestales. Instituto de Protección Forestal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marchese Garello, Mercedes Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Diodato, Maria Estela Liliana. Universidad Nacional de Santiago del Estero. Facultad de Cs.forestales. Instituto de Protección Forestal; ArgentinaFil: Tévez, Héctor. Universidad Nacional de Santiago del Estero. Facultad de Ciencias Forestales; Argentin

Invariance properties for coefficients of symmetric functions

International audienceWe show that several of the main structural constants for symmetric functions (Littlewood-Richardsoncoefficients, Kronecker coefficients, plethysm coefficients, and the Kostka–Foulkes polynomials) share invarianceproperties related to the operations of taking complements with respect to rectangles and adding rectangles.Nous montrons que plusieurs des principales constantes de structure de la théorie des fonctions symétriques(les coefficients de Littlewood–Richardson, les coefficients de Kronecker, les coefficients du pléthysme, et les polynômesde Kostka–Foulkes) ont en commun des symétries décrites par des opérations de complémentation dans des rectangleset d’ajout de rectangles pour les partitions qui les étiquettent

Reduced Kronecker coefficients and counter-examples to Mulmuley's strong saturation conjecture SH

We provide counter-examples to Mulmuley's strong saturation conjecture (strong SH) for the Kronecker coefficients. This conjecture was proposed in the setting of Geometric Complexity Theory to show that deciding whether or not a Kronecker coefficient is zero can be done in polynomial time. We also provide a short proof of the #P-hardness of computing the Kronecker coefficients. Both results rely on the connections between the Kronecker coefficients and another family of structural constants in the representation theory of the symmetric groups: Murnaghan's reduced Kronecker coefficients. An appendix by Mulmuley introduces a relaxed form of the saturation hypothesis SH, still strong enough for the aims of Geometric Complexity Theory.Comment: 25 pages. With an appendix by Ketan Mulmuley. To appear in Computational Complexity. See also http://emmanuel.jean.briand.free.fr/publications

Diversity of oligochaeta (Annelida) and Chironomidae (Diptera) of the argentinian Fluvial Litoral

Oligochaetes and chironomids are considered by many authors as biological indicators of environmental conditions and are represented for a great species diversity in the benthic, pleuston and periphyton communities of different habitats. Eighty one species of oligochaetes are reported from the Paraná River, sixty two species of Naididae, twelve Tubificidae, three Opystocistydae, one Narapidae, two Haplotaxidae and one Alluroididae. Narapa bonettoi Righi and Varela, 1983, Haplotaxis aedeochaeta Brinkhurst and Marchese, 1987, Paranadrilus descolei Gavrilov, 1955, Brinkhurstia americana (Brinkhurst, 1964), Slavina evelinae (Marcus, 1942), Limnodrilus neotropicus Cernosvitov, 1939, Trieminentia corderoi (Harman, 1969), Dero righii Varela, 1990 are endemic species of the Neotropical region. The knowledge of Chironomidae is very scarce and twenty genus were reported of Chironominae, seven Tanypodinae, and seven Orthocladiinae. The species cited in the Paraná basin are Chironomus xantus Rempel 1939, Chironomus calligraphus Goeldi, 1905; Goeldichironomus holoprasinus Goeldi, 1905; G. natans Reiss, 1974; Parachironomus supparilis (Edw. 1931) var. longistilis (Spies et al, 1994).Fil: Marchese Garello, Mercedes Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Paggi, Analia Constancia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología ; Argentin