Top dimensional group of the basic intersection cohomology for singular riemannian foliations

It is known that, for a regular riemannian foliation on a compact manifold, the properties of its basic cohomology (non-vanishing of the top-dimensional group and Poincar\'e Duality) and the tautness of the foliation are closely related. If we consider singular riemannian foliations, there is little or no relation between these properties. We present an example of a singular isometric flow for which the top dimensional basic cohomology group is non-trivial, but its basic cohomology does not satisfy the Poincar\'e Duality property. We recover this property in the basic intersection cohomology. It is not by chance that the top dimensional basic intersection cohomology groups of the example are isomorphic to either 0 or $\mathbb{R}$. We prove in this Note that this holds for any singular riemannian foliation of a compact connected manifold. As a Corollary, we get that the tautness of the regular stratum of the singular riemannian foliation can be detected by the basic intersection cohomology.Comment: 11 pages. Accepted for publication in the Bulletin of the Polish Academy of Science

Tautness for riemannian foliations on non-compact manifolds

For a riemannian foliation $\mathcal{F}$ on a closed manifold $M$, it is known that $\mathcal{F}$ is taut (i.e. the leaves are minimal submanifolds) if and only if the (tautness) class defined by the mean curvature form $\kappa_\mu$ (relatively to a suitable riemannian metric $\mu$) is zero. In the transversally orientable case, tautness is equivalent to the non-vanishing of the top basic cohomology group $H^{^{n}}(M/\mathcal{F})$, where n = \codim \mathcal{F}. By the Poincar\'e Duality, this last condition is equivalent to the non-vanishing of the basic twisted cohomology group $H^{^{0}}_{_{\kappa_\mu}}(M/\mathcal{F})$, when $M$ is oriented. When $M$ is not compact, the tautness class is not even defined in general. In this work, we recover the previous study and results for a particular case of riemannian foliations on non compact manifolds: the regular part of a singular riemannian foliation on a compact manifold (CERF).Comment: 18 page

Petrology and structure of Campanario-La Haba pluton and Los Berrocales stock (Badajoz): preliminary dates

[Abstract] The Campanario-La Haba pluton and Los Berrocales stock are situated in the southern part ofthe Central-Iberian zone. They form part ofthe late-Hercynian alignement named Caceres-Linares or Pedroches-Alburquerque. During the last years these two granitoids have been related, based on spatial and/or genetic criteria, with Los Pedroches Batholith. These igneous bodies are different. Campanario-La Haba pluton is a coarse grained peraluminous granite with large megaphenocrysts ofcordierite. Three facies are differenciated based on petrographic criteria: coarse grained porfiric granite with megaphenocryst of cordierite, fine grained porfiric granite with megaphenocryst of cordierire and fine-medium granite. Los Berrocales is a zoned stock formed by granodiorites graded to granites in the center. Structure-studies indicates that the Campanario-La Haba pluton has been structurated in magmatic state. The magmatic foliation and lineation direction show the orientation ofN12üE, parallel to the pluton lenghtening. The magnetic susceptibility values show that the magnetic behaviour of the granites is dominated by paramagnetic minerals, fine for apply the Anisotropy ofthe Magnetic Susceptibility. The magnetic structure is rather homogeneous and the magnetic lineation and foliation show the N12üE direction. This paper shows premier dates and conclusions of the work that Mineralogy and Petrology department (University of Basque Country) has being done in conjunction with the Geodinamic department (University ofBasque Country) on the westhern end of the Los Pedroches Batholith

Estructura, fábrica magnética y emplazamiento de los granitos de Brealito y La Paya, basamento del valle Calchaquí, Salta, Argentina

Los granitoides de Brealito y La Paya son plutones de formas elípticas alargadas en dirección N-S emplazados respectivamente en las Formaciones Puncoviscana y La Paya. El estudio de la estructura interna de los plutones se ha abordado aplicando la anisotropía de la susceptibilidad magnética (ASM). El plutón de La Paya presenta un carácter paramagnético (K entre 1,9 y 6,7 x10- 5 SI) con una fábrica magnética controlada por la biotita, en cambio el plutón de Brealito muestra un carácter mixto (K entre 22 y 466 x10- 5 SI) con algunas estaciones en las que la contribución ferromagnética (originada por magnetita) es dominante. Las anisotropías totales medidas son coherentes con el carácter magmático de las muestras analizadas. Ambos plutones presentan semejanzas desde el punto de vista estructural. Son cuerpos de forma lenticular, concordantes con el encajante y buzando hacia el Oeste. La lineación magnética presenta buzamientos suaves en dirección N-S.The Brealito and La Paya granitoids are elliptical-shaped plutons with N-S elongation. They intrude into the Puncoviscana and La Paya Formations, respectively. The internal structure of these plutons has been studied by using field structures and applying the Anisotropy of the Magnetic Susceptibility (AMS). The magnetic fabric of the La Paya pluton reflects the orientation of biotite, the main paramagnetic mineral in this granite (K between 1.9 and 6.7 x10-5SI). Instead, the magnetic behavior of the Brealito granite is more complex since not only paramagnetic minerals, but also the ferromagnetic contribution (K between 22 and 466 x10-5SI) of magnetite crystals strongly control the magnetic fabric of some samples. Total anisotropy values of the magnetic fabrics are coherent with the magmatic nature of the analized samples. From the structural point of view, both plutons display similarities. These granites are lozenge-shaped bodies concordant with the host rocks. Their planar fabrics are mainly NS-trending and West dipping, and magnetic lineations plunge at low angles along the N-S direction

Cohomological tautness for Riemannian foliations

In this paper we present some new results on the tautness of Riemannian foliations in their historical context. The first part of the paper gives a short history of the problem. For a closed manifold, the tautness of a Riemannian foliation can be characterized cohomologically. We extend this cohomological characterization to a class of foliations which includes the foliated strata of any singular Riemannian foliation of a closed manifold

The Sierra de Cachi (Salta, NW Argentina): geological evidence about a Famatinian retro-arc at mid crustal levels

En la Sierra de Cachi, situada en Salta (NO de Argentina), afloran rocas neoproterozoicas y paleozoicas de los Andes en un domo plutono-metamórfico flanqueado por rocas sedimentarias mesozoicas y cenozoicas. Estas rocas registran un metamorfismo de alta temperatura y baja presión, que alcanzó condiciones de fusión parcial y fue coetáneo del emplazamiento de plutones de granitos y trondhjemitas. El metamorfismo y el emplazamiento de los plutones se produjo en condiciones extensionales. Nuevos análisis de U-Pb en zircones, por los métodos TIMS y SHRIMP, proporcionan edades similares para la migmatización (479,7 ± 3,5 Ma) y el emplazamiento de los granitos (472,1 ± 11 Ma), acotando el evento extensional al Ordovícico Inferior. También describimos el hallazgo de bloques de gabros que dan una edad U-Pb SHRIMP en circones semejante, de 477,5 ± 3,9 Ma. Por lo tanto, se propone que el evento extensional descrito en la Sierra de Cachi tuvo lugar en una zona de retro-arco asociada a la subducción famatiniana del borde occidental de Gondwana. El acortamiento producido por los pliegues más jóvenes vergentes al E refleja la superposición de un campo de esfuerzos compresivos, probablemente relacionados con la orogenia Oclóyica (Ordovícico Medio/Superior-Devónico).The Cachi mountain ranges, located in Salta (NW Argentina), form an inlier where Neoproterozoic and Paleozoic materials of the Andes crop out in a plutono-metamorphic dome surrounded by Mesozoic and Cenozoic sedimentary rocks. The pre-Mesozoic rocks record a regional metamorphism of low pressure and high temperature conditions, which reached partial melting conditions and was coeval with the intrusion of sheeted granite and trondhjemite plutons. The metamorphic evolution and the emplacement of the plutons took place in an extensional tectonic setting. New U-Pb zircon dating by TIMS and SHRIMP methods yields similar ages for the migmatization (479.7 ± 3.5 Ma) and the emplacement of granites (472.1 ± 11 Ma), constraining the extensional event to Early Ordovician times. We also report the finding of gabbro boulders, which also yield a similar U-Pb SHRIMP zircon age of 477.5 ± 3.9 Ma. So, we propose that the extensional event recognized in Sierra de Cachi took place in a retro-arc setting linked to the Famatinian subduction along the western border of Gondwana. The shortening produced by younger east-verging folds evidences the superposition of a compressional stress field, probably related with the Ocloyic orogeny (Middle/Late Ordovician-Devonian)Fil: Hongn, Fernando Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Bio y Geociencias del Noroeste Argentino; ArgentinaFil: Tubía, J. M.. Universidad del Pais Vasco; EspañaFil: Esteban, J. J.. Universidad del Pais Vasco; EspañaFil: Aranguren, A.. Universidad del Pais Vasco; EspañaFil: Vegas, N.. Universidad del Pais Vasco; EspañaFil: Sergeev, S.. Centre of Isotopic Research; RusiaFil: Larionov, A.. Centre of Isotopic Research; RusiaFil: Basei, M.. Universidade de São Paulo. Instituto de Geociências; Brasi

Fertilización fosfatada e inoculación de soja en vertisoles

215-222The symbiosis between rhizobia and soybean (Glycine max (L.) Merril) provides most of the nitrogen requirements of the crop through a process that also depends on the availability of nutrients, for example phosphorous. The objective of this study was to determine the contribution of P fertilization (0, 18 y 36 kg ha-1) and Bradyrhizobium japonicum inoculation on the nodulation and grain yield of soybean crops in Vertisols with low soil P availability. In the sites without previous soybean crops, the inoculation promoted a greater nodulation, and shoot dry matter and grain yields above the non-inoculated crops. Nodulation and shoot growth increased with increasing available P (Psoil + Pfertilization) levels up to 12.4 mg kg-1. In the sites rotated with soybean, yields were greater in the inoculated crops. Shoot dry matter and grain yields increased with increasing available P levels only under inoculation. In general, the inoculated and fertilized crops showed greater production suggesting the convenience of the combined nutrition of soybean crops for achieving greater grain yields

Fertilización fosfatada e inoculación de soja en vertisoles

215-222The symbiosis between rhizobia and soybean (Glycine max (L.) Merril) provides most of the nitrogen requirements of the crop through a process that also depends on the availability of nutrients, for example phosphorous. The objective of this study was to determine the contribution of P fertilization (0, 18 y 36 kg ha-1) and Bradyrhizobium japonicum inoculation on the nodulation and grain yield of soybean crops in Vertisols with low soil P availability. In the sites without previous soybean crops, the inoculation promoted a greater nodulation, and shoot dry matter and grain yields above the non-inoculated crops. Nodulation and shoot growth increased with increasing available P (Psoil + Pfertilization) levels up to 12.4 mg kg-1. In the sites rotated with soybean, yields were greater in the inoculated crops. Shoot dry matter and grain yields increased with increasing available P levels only under inoculation. In general, the inoculated and fertilized crops showed greater production suggesting the convenience of the combined nutrition of soybean crops for achieving greater grain yields

Estrés oxidativo y alteraciones de la funcionalidad hepática en ratones hembras con hígado graso experimental

El estrés oxidativo (EO) afecta la progresión y severidad de diferentes patologías, entre las cuales se incluyen las hepáticas. Ha sido señalada su intervención en el hígado graso (HG) no alcohólico, de relevante importancia tanto en medicina humana como veterinaria debido, entre otras, a la alteración de las funciones hepáticas causada por el deterioro celular producto del EO, como es el proceso de lipoperoxidación. El objetivo de este estudio fue determinar si el HG no alcohólico experimental inducido en ratones hembra NMRI por etionina provocaba EO y afectaba a la función hepática. El HG se indujo mediante la administración de etionina (7,5 mg/20 g peso corporal), de conocida acción hepatotóxica. Se utilizaron dos grupos de 10 animales: uno control y otro tratado con DL-etionina. El HG se evaluó por métodos histológicos y mediante la cuantificación de los triglicéridos hepáticos, que indicaron hepatoesteatosis en las hembras inyectadas con etionina. La concentración hepática de malondialdehído (MDA) y de dienos conjugados (DC) se determinó por espectrofotometría como parámetros de EO. Además, en muestras de plasma se cuantificó la concentración de las aminotransferasas ALT y AST a través de kits comerciales. La inducción de HG causó una elevación significativa de los parámetros de MDA: de 258,30 ±22,49 nmoles/mg proteínas a 354,90 ±19,83 nmoles/mg proteínas (