A new limit for the NW Río de la Plata Craton Border at about 24°S (Argentina) detected by Magnetotellurics

Old South American structures constitute a puzzle where the Río de la Plata Craton is the most important clue in the assembly of SW Gondwana. The present study is aimed at characterizing the western border of the Río de la Plata Craton on the basis of magnetotelluric studies. Magnetotelluric (MT) data were acquired along an approximately NW-SE 750km profile at about 24ºS, from the Sub-Andean Ranges in the province of Salta (NW) to the Formosa Province frontier (SE) next to Paraguay River. Distortion and structure dimensionality analysis indicates that MT responses are two-dimensional with a NS strike orientation, consistent with the regional geological strike. A 2-D inversion of the data provided a model showing a lateral discontinuity, possibly associated with cratonic structures. The high resistivity observed (>5000ohm·m), from about the middle of the profile toward its eastern end, may be interpreted as the terranes accreted to the Río de la Plata Craton during Neoproterozoic to Cambrian times, or as the Río de la Plata Craton itself. Along the profile from the surface to a depth of about 10km the resistivity model shows a significant resistivity variation in the structure. The resistive block identified at the western end of the profile represents the Sub-Andean system. The markedly enhanced low-resistivity structure (~1 to 10ohm·m) corresponds to a sedimentary pile whose thickness decreases from NW to SE.Fil: Favetto, Alicia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Rocha, Veronica. Universidad Nacional de Salta. Facultad de Cs.naturales. Escuela de Geología; ArgentinaFil: Pomposiello, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Garcia, Rodolfo Fernando. Universidad Nacional de Salta. Facultad de Cs.naturales. Escuela de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Barcelona, Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; Argentin

The gravity field of the Tucuman plain and its implications in structural geology

Le résultat de la prospection gravimétrique de la plaine de Tucuman montre une fosse ayant plus de 3000 mètres de sédiments. Cette fosse est intéressante pour la prospection des hydrocarbures et l'examen géothermique. (Résumé d'auteur

A new limit for the NW Río de la Plata Craton Border at about 24ºS (Argentina) detected by Magnetotellurics

Old South American structures constitute a puzzle where the Río de la Plata craton is the most important clue in the assembly of SW Gondwana. The present study was performed to improve the knowledge resulting from all the previous magnetotelluric (MT) studies focused particularly on characterizing the western border of the Rio de la Plata Craton. MT data were acquired along an approximately NW-SE 750 km profile at about 24ºS, from the Sub Andean Ranges in the province of Salta (NW) to the boundary Formosa Province frontier (SE) next to Paraguay River. Distortion and structure dimensionality analysis indicates that MT responses are two-dimensional with a NS strike orientation, consistent with the regional geological strike. A 2D inversion of the data provided a model showing a sharp lateral discontinuity, possibly associated with cratonic structures. The high resistivity (> 5000 ohm-m) observed, from about the middle of the profile toward its eastern end, may be interpreted as the terranes accreted to the Río de la Plata Craton during Neoproterozoic to Cambrian times, or even as the Río de la Plata Craton itself. Along the profile from the surface to a depth of about 10 km the resistivity model shows a significant resistivity variation in the structure. The resistive block identified at the western end of the profile represents the Sub Andean system. The markedly enhanced low-resistivity structure (~ 1 to 10 ohm-m) corresponds to a sedimentary pile whose thickness decreases from NW to SE

A new limit for the NW Río de la Plata Craton Border at about 24ºS (Argentina) detected by Magnetotellurics

Old South American structures constitute a puzzle where the Río de la Plata Craton is the most important clue in the assembly of SW Gondwana. The present study is aimed at characterizing the western border of the Río de la Plata Craton on the basis of magnetotelluric studies. Magnetotelluric (MT) data were acquired along an approximately NW-SE 750km profile at about 24ºS, from the Sub-Andean Ranges in the province of Salta (NW) to the Formosa Province frontier (SE) next to Paraguay River. Distortion and structure dimensionality analysis indicates that MT responses are two-dimensional with a NS strike orientation, consistent with the regional geological strike. A 2-D inversion of the data provided a model showing a lateral discontinuity, possibly associated with cratonic structures. The high resistivity observed (>5000ohm·m), from about the middle of the profile toward its eastern end, may be interpreted as the terranes accreted to the Río de la Plata Craton during Neoproterozoic to Cambrian times, or as the Río de la Plata Craton itself. Along the profile from the surface to a depth of about 10km the resistivity model shows a significant resistivity variation in the structure. The resistive block identified at the western end of the profile represents the Sub-Andean system. The markedly enhanced low-resistivity structure (~1 to 10ohm·m) corresponds to a sedimentary pile whose thickness decreases from NW to SE

DNA binding shifts the redox potential of the transcription factor SoxR

Electrochemistry measurements on DNA-modified electrodes are used to probe the effects of binding to DNA on the redox potential of SoxR, a transcription factor that contains a [2Fe-2S] cluster and is activated through oxidation. A DNA-bound potential of +200 mV versus NHE (normal hydrogen electrode) is found for SoxR isolated from Escherichia coli and Pseudomonas aeruginosa. This potential value corresponds to a dramatic shift of +490 mV versus values found in the absence of DNA. Using Redmond red as a covalently bound redox reporter affixed above the SoxR binding site, we also see, associated with SoxR binding, an attenuation in the Redmond red signal compared with that for Redmond red attached below the SoxR binding site. This observation is consistent with a SoxR-binding-induced structural distortion in the DNA base stack that inhibits DNA-mediated charge transport to the Redmond red probe. The dramatic shift in potential for DNA-bound SoxR compared with the free form is thus reconciled based on a high-energy conformational change in the SoxR–DNA complex. The substantial positive shift in potential for DNA-bound SoxR furthermore indicates that, in the reducing intracellular environment, DNA-bound SoxR is primarily in the reduced form; the activation of DNA-bound SoxR would then be limited to strong oxidants, making SoxR an effective sensor for oxidative stress. These results more generally underscore the importance of using DNA electrochemistry to determine DNA-bound potentials for redox-sensitive transcription factors because such binding can dramatically affect this key protein property

Electrical conductivity of the Pampean Shallow Subduction Region of Argentina near 33 S: evidence for a slab window

We present a three-dimensional (3-D) interpretation of 117 long period (20–4096 s) magnetotelluric (MT) sites between 31°S and 35°S in western Argentina. They cover the most horizontal part of the Pampean shallow angle subduction of the Nazca Plate and extend south into the more steeply dipping region. Sixty-two 3-D inversions using various smoothing parameters and data misfit goals were done with a nonlinear conjugate gradient (NLCG) algorithm. A dominant feature of the mantle structure east of the horizontal slab is a conductive plume rising from near the top of the mantle transition zone at 410 km to the probable base of the lithosphere at 100 km depth. The subducted slab is known to descend to 190 km just west of the plume, but the Wadati-Benioff zone cannot be traced deeper. If the slab is extrapolated downdip it slices through the plume at 250 km depth. Removal of portions of the plume or blocking vertical current flow at 250 km depth significantly changes the predicted responses. This argues that the plume is not an artifact and that it is continuous. The simplest explanation is that there is a “wedge”-shaped slab window that has torn laterally and opens down to the east with its apex at the plume location. Stress within the slab and seismic tomography support this shape. Its northern edge likely explains why there is no deep seismicity south of 29°S.Fil: Burd, Aurora I.. University of Washington; Estados UnidosFil: Booker, John R.. University of Washington; Estados UnidosFil: Mackie, Randall. Land General Geophysics; ItaliaFil: Pomposiello, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotopica; ArgentinaFil: Favetto, Alicia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotopica; Argentin

From acute injury to chronic disease: pathophysiological hypothesis of an epithelial/mesenchymal crosstalk alteration in CKD

Observational clinical studies link acute kidney injury to chronic kidney disease (CKD) progression. The pathophysiological mechanisms that underlie this process are currently unknown but recently published papers suggest that tubular epithelial cells and interstitial mesenchymal cells emerge as a single unit, and their integrity alteration as a whole might lead to renal fibrosis and CKD. The present article reviews the biological findings supporting the hypothesis of an altered epithelial/mesenchymal crosstalk in fibrosis development and progression toward CK

Geothermal system of Despoblados by magnetotelluric data, Valle del Cura, San Juan

El Valle del Cura se emplaza dentro de un sistema de corrimientos N-S en la alta cordillera de San Juan. Este valle presenta manifestaciones geotermales variadas destacándose los manantiales hipertermales de Despoblados. El objetivo de este trabajo fue estudiar el fenómeno geotermal mediante magnetotelúrica de alta resolución para resolver la geometría del sistema en profundidad. Se midió alta frecuencia (1000 - 10 Hz) en 47 sitios y banda ancha (10 - 0,03 Hz) en 18 sitios. Se efectuó un procesamiento robusto de la señal y un análisis estándar de sus propiedades. Inversiones 2-D permitieron caracterizar la distribución de la resistividad eléctrica del subsuelo mediante 5 modelos luego integrados en uno pseudo 3-D. Los modelos definen dos anomalías conductivas, una de ellas directamente vinculada con los manantiales calientes y la otra sin expresión superficial. Ambas evidencian un fuerte control estructural y una circulación profunda de fluidos geotermales. El modelo del sistema geotermal propuesto para Despoblados implica zonas de surgencia tipo plumas canalizadas por las fallas que controlan la geometría del valle y zonas de recarga asociadas a los corrimientos principales, por donde se infiltra agua meteórica. No existe evidencia de un nivel estratigráfico somero que conforme el reservorio, aunque no se descarta la existencia de uno más profundo. La circulación profunda de fluidos bajo un gradiente geotérmico normal favorecería la convección, aunque no se descarta que esté localmente controlada por una anomalía térmica remanente del volcanismo del Cerro de Vidrio (1,5Ma). Finalmente, se abren interrogantes sobre la existencia de un sistema geotermal mayor que integre todas las manifestaciones de Valle del Cura.Valle delCura develops within a N-S thrust system in the high cordillera of San Juan. This valley has various geothermal manifestations, where the hot springs of Despoblados are highlighted. The aim of the work was to study the geothermal phenomenon by magnetotellurics, in order to obtain the geometry of the system in depth. High frecuency (1000 - 10 Hz) and broad band (10 - 0.03 Hz) were recorded in 47 and 18 sites. Robust signal processing and standard parameters analysis were performed. 2-D inversion of the data was carried out to obtain the electrical resistivity distribution through five models and a single pseudo 3-D model. The models defined two conductive anomalies, one directly linked with the hot springs and the other one without superficial manifestation. Both anomalies show structural control and a deep circulation of geothermal fluids. The proposed Despoblados geothermal system has plumes like upwelling zones channeled by faults that surround the valley and downwelling zones linked to the main thrusts, were the meteoric water leaks. Although there is no evidence of shallow lithostratigraphic level as reservoir, is not discarded the existence of one bellow 4000 m depth. The geothermal fluid circulation could be by normal geothermal gradient convection or favored by a remnant thermal anomaly from the Cerro de Vidrio volcanic event (1.5 Ma). Finally, some questions remains about the existence of a main geothermal systems that groups the apparent isolated manifestations on Valle del Cura.Fil: Barcelona, Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Favetto, Alicia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Peri, Verónica Gisel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Pomposiello, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Ostera, Hector Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; Argentin

Actividad, composición y distribución de tamaño de partículas de aerosol producidas por mezclas pirotécnicas que contienen I2Pb y I2Pb+IK

El objeto de este trabajo fue estudiar la dependencia de la actividad glaceógena de núcleos artificiales respecto al sobreenfriamiento del sistema (-6°C a -20°C) para mezclas pirotécnicas que contienen I2Pb y I2pb + IK. Se determinó, para las mismas, la distribución de tamaños usando un microscopio electrónico de transmisión comprobándose que las partículas del aerosol son submicrónicas (ø<200Á). Además se identificó la composición de las partículas por medio del análisis de difracción de electrones y de rayos-X.The purpose of this research work was to study the dependence of freezing activity of artificial nuclei in relation to the supercooling of the system (-6°C to -20°C) for pyrotechnic mixtures that contain l2Pb and I2pb + IK. Their size distribution was determined using a transmission electronic microscope. The aerosol particles proved to be submicronic (ø<200Á). Besides, the composition of the particles was analysed through electronic diffraction and X-rays.Asociación Argentina de Geofísicos y Geodesta