Secular variations of magma source compositions in the North Patagonian batholith from the Jurassic to Tertiary: Was mélange melting involved?

This study of Sr-Nd initial isotopic ratios of plutons from the North Patago nian batholith (Argentina and Chile) revealed that a secular evolution spanning 180 m.y., from the Jurassic to Neogene, can be established in terms of magma sources, which in turn are correlated with changes in the tectonic regime. The provenance and composition of end-member components in the source of mag mas are represented by the Sr-Nd initial isotopic ratios (87Sr/86Sr and 143Nd/144Nd) of the plutonic rocks. Our results support the interpretation that source compo sition was determined by incorporation of varied crustal materials and trench sediments via subduction erosion and sediment subduction into a subduction channel mélange. Subsequent melting of subducted mélanges at mantle depths and eventual reaction with the ultramafic mantle are proposed as the main causes of batholith magma generation, which was favored during periods of fast conver gence and high obliquity between the involved plates. We propose that a parental diorite (= andesite) precursor arrived at the lower arc crust, where it underwent fractionation to yield the silicic melts (granodiorites and granites) that formed the batholiths. The diorite precursor could have been in turn fractionated from a more mafic melt of basaltic andesite composition, which was formed within the mantle by complete reaction of the bulk mélanges and the peridotite. Our proposal follows model predictions on the formation of mélange diapirs that carry fertile subducted materials into hot regions of the suprasubduction mantle wedge, where mafic parental magmas of batholiths originate. This model not only accounts for the secular geochemical variations of Andean batholiths, but it also avoids a fundamental paradox of the classical basalt model: the absence of ultramafic cumulates in the lower arc crust and in the continental crust in general

Dyonic Integrable Models

A class of non abelian affine Toda models arising from the axial gauged two-loop WZW model is presented. Their zero curvature representation is constructed in terms of a graded Kac-Moody algebra. It is shown that the discrete multivacua structure of the potential together with non abelian nature of the zero grade subalgebra allows soliton solutions with non trivial electric and topological charges. The dressing transformation is employed to explicitly construct one and two soliton solutions and their bound states in terms of the tau functions. A discussion of the classical spectra of such solutions and the time delays are given in detail.Comment: Latex 30 pages, corrected some typo

A salivary metabolite signature that reflects gingival host-microbe interactions: instability predicts gingivitis susceptibility

Several proteins and peptides in saliva were shown to stimulate gingival wound repair, but the role of salivary metabolites in this process remains unexplored. In vitro gingival re-epithelialization kinetics were determined using unstimulated saliva samples from healthy individuals collected during an experimental gingivitis study. Elastic net regression with stability selection identified a specific metabolite signature in a training dataset that was associated with the observed re-epithelialization kinetics and enabled its prediction for all saliva samples obtained in the clinical study. This signature encompassed ten metabolites, including plasmalogens, diacylglycerol and amino acid derivatives, which reflect enhanced host-microbe interactions. This association is in agreement with the positive correlation of the metabolite signature with the individual’s gingival bleeding index. Remarkably, intra-individual signature-variation over time was associated with elevated risk for gingivitis development. Unravelling how these metabolites stimulate wound repair could provide novel avenues towards therapeutic approaches in patients with impaired wound healing capacity.</p

Multicharged Dyonic Integrable Models

We introduce and study new integrable models of A_n^{(1)}-Non-Abelian Toda type which admit U(1)\otimes U(1) charged topological solitons. They correspond to the symmetry breaking SU(n+1) \to SU(2)\otimes SU(2)\otimes U(1)^{n-2} and are conjectured to describe charged dyonic domain walls of N=1 SU(n+1) SUSY gauge theory in large n limit. It is shown that this family of relativistic IMs corresponds to the first negative grade q={-1} member of a dyonic hierarchy of generalized cKP type. The explicit relation between the 1-soliton solutions (and the conserved charges as well) of the IMs of grades q=-1 and q=2 is found. The properties of the IMs corresponding to more general symmetry breaking SU(n+1) \to SU(2)^{\otimes p}\otimes U(1)^{n-p} as well as IM with global SU(2) symmetries are discussed.Comment: 48pages, latex, v2. typos in eqns. (1.7) and (3.20) corrected, small improvements in subsection 2.2, new reference added;v3. improvements in text of Sect. 1,2 and 6; new Sect 7 and new refs. added; version to appear in Nucl. Phys.

Influencia de las propiedades edáficas sobre el crecimiento de Schinopsis balansae Engler en el Parque Chaqueño Húmedo (Argentina) = Influence of soil properties on the growth of Schinopsis balansae Engler in the Humid Parque Chaqueño (Argentina)

Schinopsis balansae (quebracho colorado chaqueño) es una especie dominante característica del Chaco Húmedo Argentino, que se desarrolla en suelos con limitaciones físicas escasamente reversibles, que sólo las especies arbóreas de alta rusticidad pueden colonizarlos. El objetivo del trabajo fue analizar las propiedades edáficas que pueden influir sobre el crecimiento y desarrollo de reforestaciones con S. balansae en la ecorregión del Chaco Húmedo argentino. Al efecto fueron seleccionados cuatro sitios forestados con S. balansae en la ecorregión del Chaco Húmedo en el Parque Chaqueño Oriental. Las plantaciones de la misma franja etaria (10 - 12 años), similar distancia de plantación (4 m x 4 m) y estado sanitario. En cada sitio se seleccionaron 12 árboles representativos, midiéndose el diámetro altura de pecho (DAP) y la altura de fuste, tomándose muestras de suelo a 0 a -10; -10 a -25; -25 a -55; y -55 a -115 cm de profundidad. Se realizaron las siguientes determinaciones: textura; densidad aparente (Da); porosidad capilar (Pmc); pH; conductividad eléctrica (CE); materia orgánica edáfica (MOS); Ca2+, K+ y Na+ de cambio; y relación de adsorción de sodio (RAS). Se concluye que las propiedades edáficas condicionantes para el crecimiento y desarrollo de forestaciones con quebracho colorado chaqueño son la salinidad (positivamente, relacionada con la conductividad eléctrica) y negativamente la textura (exceso de arcilla) que afectarían a la instalación y crecimiento del quebracho colorado chaqueño; aunque en profundidad se prefiere un aumento de la RAS, pero manteniéndose una moderada salinidad.Schinopsis balansae (quebracho colorado chaqueño) is a dominant species, characteristic of the humid Chaco (Argentina) where the quality of the soil is often low, primarily due to physical limitations (poor drainage), i.e., where only tree species of high rusticity can colonize. The objective of the study was to analyze the edaphic properties that may influence the growth and development of reforestation using quebracho (S. balansae) in the Argentine humid Chaco ecoregion. For this purpose, four sites forested with plantations of the same age (years 10-12), similar distance (4 x 4 m2) and health status of S. balansae were selected. In each site, twelve individuals were measured at their diameter at height of chest (DAP) and trunk length (H), and its soil sampled at 0 to - 10; -10 to - 25; -25 to - 55; and - 55 to - 115 cm depth. The following parameters were measured: texture; bulk density (Da); capillary porosity (Pmc); pH; electrical conductivity (CE); soil organic matter (MOS); exchangeable Ca2+, K+ and Na+; and (RAS) sodium adsorption ratio. It is concluded that the edaphic properties conditioning the growth and development of afforestations with quebracho colorado chaqueño are salinity (positively, related to electrical conductivity) and texture (negatively, excess of clay) that would affect the installation and growth of the quebracho colorado chaqueño; even though, concerning depth, an increase in de RAS is preferred, though keeping a moderate salinity.EEA CorrientesFil: Prause, Juan. Universidad Nacional del Chaco Austral; ArgentinaFil: Fernandez Lopez, Carolina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Corrientes; ArgentinaFil: Gallardo Lancho, J.F. Consejo Superior de Investigaciones Científicas (C.S.I.C.). Instituto de Recursos Naturales y Agrobiología de Salamanca; Españ

Spin tunnelling in mesoscopic systems

We study spin tunnelling in molecular magnets as an instance of a mesoscopic phenomenon, with special emphasis on the molecule Fe8. We show that the tunnel splitting between various pairs of Zeeman levels in this molecule oscillates as a function of applied magnetic field, vanishing completely at special points in the space of magnetic fields, known as diabolical points. This phenomena is explained in terms of two approaches, one based on spin-coherent-state path integrals, and the other on a generalization of the phase integral (or WKB) method to difference equations. Explicit formulas for the diabolical points are obtained for a model Hamiltonian.Comment: 13 pages, 5 figures, uses Pramana style files; conference proceedings articl

Herramienta de autoría de contenidos didácticos multimedia para entorno de formación colaborativo en cirugía de mínima invasión

Dada la gran importancia de los contenidos para el éxito del proceso de formación es necesario desarrollar herramientas que permitan la creación de los mismos de una manera simple, eficaz y motivadora. Actualmente, su proceso de creación es largo y costoso, teniendo que llevarlo a cabo expertos cirujanos docentes en estrecha colaboración con técnicos especialistas en herramientas de edición y creación de contenidos multimedia. El presente trabajo de investigación presenta una nueva herramienta de autoría que permite la creación y edición de contenidos didácticos multimedia que son utilizados en el proceso de formación de los cirujanos. La herramienta incorpora un editor multimedia de vídeos laparoscópicos, capaz de realizar un procesamiento y agregar valor didáctico a los vídeos originales. La herramienta de autoría se incorpora en un entorno de formación web que permite crear, compartir y reutilizar contenidos didácticos basados en la edición de vídeo laparoscópico

Induction of a gloverin-like antimicrobial polypeptide in the sugarcane borer Diatraea saccharalis challenged by septic injury

Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) is an important pest for Brazilian sugarcane. In the present study, we detected two distinct spots in hemolymph from septic injured larvae (HDs1 and HDs2), which are separated by 2DE gel electrophoresis. Both spots were subjected to in-gel tryptic digestion and MALDI-TOF/TOF analysis, which revealed the sequence VFGTLGSDDSGLFGK present in both HDs1 and HDs2. This sequence had homology and 80% identity with specific Lepidoptera antimicrobial peptides called gloverins. Analyses using the ImageMaster 2D software showed pI 8.94 of the HDs1 spot, which is similar to that described to Hyalophora gloveri gloverin (pI 8.5). Moreover, the 14-kDa molecular mass of the spot HDs1 is compatible to that of gloverins isolated from the hemolymph of Trichoplusia ni, Helicoverpa armigera and H. gloveri. Antimicrobial assays with partially purified fractions containing the HDs1 and HDs2 polypeptides demonstrated activity against Escherichia coli. This is the first report of antimicrobial polypeptides in D. saccharalis, and the identification of these peptides may help in the generation of new strategies to control this pest

Los nombres del Oppidum de Monte Bernorio (Villarén, Palencia):Las denominaciones de los Oppida Célticos del norte de la península ibérica: estructura política e identidad étnica

El objetivo de este trabajo es abordar el problema del nombre que podía haber recibido el oppidum de Monte Bernorio (Palencia). La cuestión de las denominaciones de los oppida y de los grupos étnicos que habitaban los distintos territorios se pone en relación con casos similares del norte de la Península Ibérica y del occidente de Europa. Finalmente, en relación con la cuestión de los nombres de los oppida se aborda también la problemática de los etnónimos de los pueblos célticos en relación con su organización social y estructuras políticasThis paper discusses the problem of identifying the name by which the oppidum of Monte Bernorio (Palencia) was known. The denomination of the oppida and of the communities that inhabited them is compared with similar cases from Iberia and Western Europe. Finally, we analyse the question of the ethnic names of the so-called Celtic populations in relation to their social organisation and political structur

T-duality of axial and vector dyonic integrable models

A general construction of affine Non Abelian (NA) - Toda models in terms of axial and vector gauged two loop WZNW model is discussed. They represent {\it integrable perturbations} of the conformal $\sigma$-models (with tachyons included) describing (charged) black hole type string backgrounds. We study the {\it off-critical} T-duality between certain families of axial and vector type of integrable models for the case of affine NA- Toda theories with one global U(1) symmetry. In particular we find the Lie algebraic condition defining a subclass of {\it T-selfdual} torsionless NA Toda models and their zero curvature representation.Comment: 20 pages, latex, no figures,improvments in the text of Sects.1,2 and 6;typos corrected,references added, to appear in Ann. of Physics (NY