Time-lapse cross-hole electrical resistivity tomography (CHERT) for monitoring seawater intrusion dynamics in a Mediterranean aquifer

Surface electrical resistivity tomography (ERT) is a widely used tool to study seawater intrusion (SWI). It is noninvasive and offers a high spatial coverage at a low cost, but its imaging capabilities are strongly affected by decreasing resolution with depth. We conjecture that the use of CHERT (cross-hole ERT) can partly overcome these resolution limitations since the electrodes are placed at depth, which implies that the model resolution does not decrease at the depths of interest. The objective of this study is to test the CHERT for imaging the SWI and monitoring its dynamics at the Argentona site, a well-instrumented field site of a coastal alluvial aquifer located 40¿km NE of Barcelona. To do so, we installed permanent electrodes around boreholes attached to the PVC pipes to perform time-lapse monitoring of the SWI on a transect perpendicular to the coastline. After 2 years of monitoring, we observe variability of SWI at different timescales: (1) natural seasonal variations and aquifer salinization that we attribute to long-term drought and (2) short-term fluctuations due to sea storms or flooding in the nearby stream during heavy rain events. The spatial imaging of bulk electrical conductivity allows us to explain non-monotonic salinity profiles in open boreholes (step-wise profiles really reflect the presence of freshwater at depth). By comparing CHERT results with traditional in situ measurements such as electrical conductivity of water samples and bulk electrical conductivity from induction logs, we conclude that CHERT is a reliable and cost-effective imaging tool for monitoring SWI dynamics.This work was funded by the project CGL2016-77122-C2-1-R/2-R of the Spanish Government. This project also received funding from the European Commission, Horizon 2020 research and innovation programme (Marie Sklodowska-Curie (grant no. 722028)). The author Albert Folch is a Serra Húnter Fellow.Peer ReviewedPostprint (published version

The AMBRE Project: Stellar parameterisation of the ESO:FEROS archived spectra

The AMBRE Project is a collaboration between the European Southern Observatory (ESO) and the Observatoire de la Cote d'Azur (OCA) that has been established in order to carry out the determination of stellar atmospheric parameters for the archived spectra of four ESO spectrographs. The analysis of the FEROS archived spectra for their stellar parameters (effective temperatures, surface gravities, global metallicities, alpha element to iron ratios and radial velocities) has been completed in the first phase of the AMBRE Project. From the complete ESO:FEROS archive dataset that was received, a total of 21551 scientific spectra have been identified, covering the period 2005 to 2010. These spectra correspond to ~6285 stars. The determination of the stellar parameters was carried out using the stellar parameterisation algorithm, MATISSE (MATrix Inversion for Spectral SynthEsis), which has been developed at OCA to be used in the analysis of large scale spectroscopic studies in galactic archaeology. An analysis pipeline has been constructed that integrates spectral reduction and radial velocity correction procedures with MATISSE in order to automatically determine the stellar parameters of the FEROS spectra. Stellar atmospheric parameters (Teff, log g, [M/H] and [alpha/Fe]) were determined for 6508 (30.2%) of the FEROS archived spectra (~3087 stars). Radial velocities were determined for 11963 (56%) of the archived spectra. 2370 (11%) spectra could not be analysed within the pipeline. 12673 spectra (58.8%) were analysed in the pipeline but their parameters were discarded based on quality criteria and error analysis determined within the automated process. The majority of these rejected spectra were found to have broad spectral features indicating that they may be hot and/or fast rotating stars, which are not considered within the adopted reference synthetic spectra grid of FGKM stars.Comment: 28 pages, 28 figures, 9 table

Respuesta de la ahuyama (Curcubita maxima L.) a la fertilización con N, P, K y materia orgánica en el Valle del Cauca.

En un suelo de la serie Palmeras (PM) clasificado como Vertic ustropept del CNI Palmira, se realizó en 1986 una investigación para evaluar el efecto de la fertilización química y orgánica en el rendimiento del zapallo (Cucurbita maxima L.) variedad peruana. Se estudiaron 27 combinaciones de N-P-K (factorial) más 3 dosis de materia orgánica MO (gallinaza), en un diseño de bloques completos al azar con 3 repeticiones. El P y K se aplicaron 8 días después de la siembra, el N y la MO fraccionadas, en 2 aplicaciones iguales, 8 y 30 días después de la siembra. Los niveles de cada nutriente, en kg/ha, fueron: 0, 25 y 50 de N, 0, 50 y 100 de oxido fosfórico, 0, 25 y 50 kg/ha de oxido de potasio y 2.5, 5.0 y 7.5 t/ha de gallinaza. Hubo diferencias de 19.78 y 19.71 t/ha entre los 2 rendimientos más altos, correspondientes a los tratamientos 50-100-25 y 50-50-25, en su orden y el rendimiento más bajo (25-100-50). Respecto al testigo absoluto se observaron incrementos en rendimiento de 15.03 y 14.83 por ciento, respectivamente. Con las aplicaciones individuales la principal respuesta se obtuvo con 50 kg/ha de oxido fosfórico, para un incremento en rendimiento de 7.4 por ciento con relación al testigo absoluto, el K, en dosis de 25 y 50 kg/ha oxido de potasio, disminuyó el rendimiento en 34 y 22.3 por ciento, respectivamente. Los tratamientos con MO aumentaron el rendimiento en 126, 131 y 105 por ciento, respectivamente, usando dosis de 2.5, 5.0 y 7.5 t/ha de gallinaza. El mayor número de frutos comerciales se obtuvo con aplicaciones de 50-100-25 kg/ha de N, P O y K O, respectivamente. El tratamiento 25-50-25 t/ha de gallinaza, kg P O /ha y kg K O/ha respectivamente, produjo el más alto peso promedio de frutos. El mayor número de flores femeninas (43.3 y 39.3) se consiguió aplicando 5 t/ha de gallinaza, más 50-25 kg/ha de P O y K O y 50-50-25 kg/ha de N, P O y K su orden.;Las relaciones flor femenina-flormasculina más altas (4.76 y 3.88) se obtuvieron con la aplicación de 100 kg/ha de P O y 25-50-0 kg/ha de N, P O y K. Para agricultores con suficiente capital se recomienda el tratamiento 50-50-25 kg/ha de N, P O y K O por presentar: tasa alta de retorno marginal (TRM), mayor beneficio neto, y consistencia a las fluctuaciones de precios de los insumos. Para cultivadores de escasos recursos se recomiendan los tratamientos 25-0-25 y 0-50-0 kg/ha de N, P O y K O, con los cuales se obtiene una TRM alta, menores costos variables y consistencia a fluctuaciones de precios de los insumosAhuyama-Calabaza (cucúrbita), Cucurbita máxim

Coupling Nd3+:Y2O3 fluorescent submicron particles to linear plasmonic chains

We report on the fabrication and optical characterization of a new hybrid material consisting of Nd3+ doped Y2O3 submicron particles associated with linear chains of plasmonic nanostructures. By drop-casting deposition, single Nd3+ doped Y2O3 polycrystalline particles are dispersed and located in the vicinities of plasmonic chains of silver nanoparticles formed on the surface a LiNbO3 substrate. The interaction between the plasmonic modes of the chain with the fluorescent yttria submicron particles is analyzed by micro-luminescence experiments. Orthogonal polarization configurations of the excitation radiation, namely, perpendicular and parallel to plasmonic chain axis, are employed to study the effect of the longitudinal and transverse chain plasmonic modes on the luminescence of the particles. A remarkable dependence of the emission intensity of the Nd3+:Y2O3 submicron particles on the excitation polarization is observed, showing the capability of plasmonic chains to modulate the emission of fluorescent submicron particles in contact with the chain. Numerical simulations evidence a different distribution of the excitation radiation field within the Nd3+:Y2O3 particle depending on the type of excited plasmonic mode, longitudinal or transversal, of the chain, and hence, the ability of plasmonic chains for controlling the emission of Rare Earth doped submicron particlesThis work has been supported by the Spanish State Research Agency under contracts PID2019-108257GB-I00, PID2022-137444NB-I00 and the María de Maeztu “Programme for Units of Excellence in R&D″ CEX2018-000805-M. P.G acknowledges funding from the French Agence Nationale de la Recherche under grant ANR-20-CE09-0022 (UltraNanOSpec

Correlation and symmetry effects in transport through an artificial molecule

Spectral weights and current-voltage characteristics of an artificial diatomic molecule are calculated, considering cases where the dots connected in series are in general different. The spectral weights allow us to understand the effects of correlations, their connection with selection rules for transport, and the role of excited states in the experimental conductance spectra of these coupled double dot systems (DDS). An extended Hubbard Hamiltonian with varying interdot tunneling strength is used as a model, incorporating quantum confinement in the DDS, interdot tunneling as well as intra- and interdot Coulomb interactions. We find that interdot tunneling values determine to a great extent the resulting eigenstates and corresponding spectral weights. Details of the state correlations strongly suppress most of the possible conduction channels, giving rise to effective selection rules for conductance through the molecule. Most states are found to make insignificant contributions to the total current for finite biases. We find also that the symmetry of the structure is reflected in the I-V characteristics, and is in qualitative agreement with experiment.Comment: 25 figure files - REVTEX - submitted to PR

Mutations related to Antiretroviral Resistance identified by ultra-deep sequencing in HIV-1 infected children under Structured Interruptions of HAART

Altres ajuts: CONACYT/GCPS/44519Although Structured Treatment Interruptions (STI) are currently not considered an alternative strategy for antiretroviral treatment, their true benefits and limitations have not been fully established. Some studies suggest the possibility of improving the quality of life of patients with this strategy; however, the information that has been obtained corresponds mostly to studies conducted in adults, with a lack of knowledge about its impact on children. Furthermore, mutations associated with antiretroviral resistance could be selected due to sub-therapeutic levels of HAART at each interruption period. Genotyping methods to determine the resistance profiles of the infecting viruses have become increasingly important for the management of patients under STI, thus low-abundance antiretroviral drug-resistant mutations (DRM's) at levels under limit of detection of conventional genotyping (<20% of quasispecies) could increase the risk of virologic failure. In this work, we analyzed the protease and reverse transcriptase regions of the pol gene by ultra-deep sequencing in pediatric patients under STI with the aim of determining the presence of high- and low-abundance DRM's in the viral rebounds generated by the STI. High-abundance mutations in protease and high- and low-abundance mutations in reverse transcriptase were detected but no one of these are directly associated with resistance to antiretroviral drugs. The results could suggest that the evaluated STI program is virologically safe, but strict and carefully planned studies, with greater numbers of patients and interruption/restart cycles, are still needed to evaluate the selection of DRM's during STI

VdBH 222: a starburst cluster in the inner Milky Way

Context. It has been suggested that the compact open cluster VdBH 222 is a young massive distant object.Aims. We set out to characterise VdBH 222 using a comprehensive set of multi-wavelength observations.Methods.We obtained multi-band optical (UBVR) and near-infrared (JHKS) photometry of the cluster field, as well as multi-object and long-slit optical spectroscopy for a large sample of stars in the field. We applied classical photometric analysis, as well as more sophisticated methods using the CHORIZOS code, to determine the reddening to the cluster. We then plotted dereddened HR diagrams and determined cluster parameters via isochrone fitting.Results. We have identified a large population of luminous supergiants confirmed as cluster members via radial velocity measurements. We find nine red supergiants (plus one other candidate) and two yellow supergiants. We also identify a large population of OB stars. Ten of them are bright enough to be blue supergiants. The cluster lies behind ≈7.5 mag of extinction for the preferred value of RV = 2.9. Isochrone fitting allows for a narrow range of ages between 12 and 16 Ma. The cluster radial velocity is compatible with distances of ~6 and ~10 kpc. The shorter distance is inconsistent with the age range and Galactic structure. The longer distance implies an age ≈ 12 Ma and a location not far from the position where some Galactic models place the far end of the Galactic bar.Conclusions. VdBH 222 is a young massive cluster with a likely mass >20 000 M⊙. Its population of massive evolved stars is comparable to that of large associations, such as Per OB1. Its location in the inner Galaxy, presumably close to the end of the Galactic bar, adds to the increasing evidence for vigorous star formation in the inner regions of the Milky Way

Factores asociados a la calidad de la atención en población adulta afiliada a la Seguridad Social: El caso peruano

Objetive: To identify factors associated with perceived quality of care in the adult population affiliated with Social Security Health (EsSalud) Material and methods: We analyzed the National Socioeconomic Survey of Access to Health of the EsSalud Insured. Perceived quality of health care was evaluated in ambulatory care, hospitalization and emergency medical services. We reported adjusted ratios of means (RMa) estimated by multiple Poisson regression. Results: Being employed (RMa=0.98; IC95% 0.96-0.99), not knowing the services provided by EsSalud (RMa=0.97; IC95% 0.95-1.00), not receiving information about right to health (RMa=0.95; IC95% 0.93-0.98), perceiving as low the level of accessibility to the health facility (RMa=0.97; IC95% 0.95-0.99) and not feeling comfortable in the health facility of EsSalud (RM=0.92; IC95% 0.91-0.94) were factors associated with lower scores of perceived quality in ambulatory care. In hospitalization, being between 40-59 years old (RMa=0.93; IC95% 0.88-0.97), having a low wealth index (RMa=0.92; IC95% 0.87-0.97), not having received information about right to health (RMa=0.90; IC95% 0.84-0.95) and not feeling comfortable in the health facility of EsSalud (RMa=0.92; IC95% 0.89-0.96) were associated with lower quality score. In emergency, not feeling comfortable in the health facility of EsSalud (RMa=0.89; IC95% 0.93-1.00) was the only factor associated with a lower perceived quality score. Conclusions: We identified factors related to users and service offerings independently associated with perceived quality of care, which can be considered by decision makers for better management of EsSalud.Objetivo: Identificar factores asociados a calidad percibida de atención en la población adulta afiliada al Seguro Social en Salud (EsSalud). Material y métodos: Analizamos la Encuesta Nacional Socioeconómica de Acceso a la Salud de los Asegurados de EsSalud. La calidad percibida fue evaluada en consultorio externo, hospitalización y emergencias. Reportamos razones de medias ajustadas (RMa) estimadas mediante regresión de Poisson múltiple. Resultados: Estar empleado (RMa=0,98; IC95% 0,96-0,99), no conocer los servicios que brinda EsSalud (RMa=0,97; IC95% 0,95-1,00), no recibir información sobre los derechos como usuarios (RMa=0,95; IC95% 0,93-0,98), valorar como bajo el nivel de accesibilidad al EESS (RMa=0,97; IC95% 0,95-0,99) y no sentirse cómodo en el EESS al que acude (RM=0,92; IC95% 0,91-0,94) fueron factores asociados a menor puntaje de calidad percibida en consultorio externo. En hospitalización, tener entre 40-59 años (RMa=0,93; IC95% 0,88-0,97), contar con un índice de riqueza bajo (RMa=0,92; IC95% 0,87-0,97), no haber recibido información sobre los derechos como usuarios (RMa=0,90; IC95% 0,84-0,95) y no sentirse cómodos en el EESS (RMa=0,92; IC95% 0,89-0,96) se asociaron a menor puntuación de calidad. En emergencia, no sentirse cómodo en el EESS (RMa=0,89; IC95% 0,93-1,00) fue el único factor asociado a una menor puntuación de calidad percibida. Conclusiones: Identificamos factores relativos a los usuarios y a la oferta de servicios independientemente asociados a calidad percibida de atención, los cuales pueden ser considerados por los tomadores de decisiones para la mejor gestión de EsSalud

Ventilación líquida. Metaanálisis y revisión sistemática de la literatura

Introducción: En 1990 con base en las propiedades de los pfc (perfluorocarbonos) se realizó el primer ensayo clínico de ventilación líquida en humanos, en seis recién nacidos prematuros con insuficiencia respiratoria grave observándose mejoría significativa en la oxigenación y en la distensibilidad pulmonar. ¿Qué son los pfc? Producidas en la Segunda Guerra Mundial, son sustancias químicas cuyas propiedades dependen de la unión de los átomos de Fluor-Carbono. Su utilidad para la ventilación mecánica depende de su capacidad de disolver 20 veces más O2 y 3 veces más CO2, que el plasma, evaporándose más rápidamente que el agua a temperatura corporal. Los pfc han sido aprobados para aplicaciones biomédicas como transportadores de oxigeno aplicados intravenosos en situaciones de desastres o en individuos que rechazan ser transfundidos, sin embargo, el interés se ha despertado para su uso en la ventilación mecánica y en el síndrome de insuficiencia respiratoria aguda (sira). Por ello, el objetivo de este metaanálisis y revisión sistemática es la valoración de su uso, en especial de la década de los 90 hasta 2020. Analizando lo que dice la literatura y cómo ha funcionado en pacientes con Covid-19 y sira que ameritaron internamiento en unidades de cuidados intensivos. Material y métodos: Se buscaron revisiones sistemáticas, metaanálisis y ensayos clínicos de las revistas The New England Journal of Medicine, The Lancet , Science, Journal of Apply Physiology, Crit Care Med, Chest, Lung, Journal of Pediatrics, American Journal of Respiratory and Critical Care Medicine, Medicina Intensiva, Revista de la Facultad de Medicina de la UNAM, utilizando las bases de datos de Pubmed, medline, y www.mdconsult.com. Se buscó que los artículos estuvieran enfocados en los resultados del uso de la Ventilación Líquida, tanto en recién nacidos, prematuros, en lactantes y en adultos. El estudio se llevó a cabo de agosto de 2021 a febrero de 2022 y se realizó en el Departamento de Neumología de la Facultad de Medicina de la Universidad Autónoma del Estado de México. Resultados y Discusión: Para el año 2000 existían 1104 publicaciones sobre ventilación líquida, y 564 de ellas eran ensayos clínicos en humanos (medline), que demostraban que la Ventilación Líquida Parcial resulta más ventajosa en neonatos. En adultos sólo ha habido pocos resultados buenos con la Ventilación Líquida Total que mantiene recirculando los pfc dentro de un sistema cerrado. En las revisiones de la Fundación Cochrane se ha demostrado en dos revisiones sistemáticas y en dos metaanálisis que no hay pruebas de efectos beneficiosos de la ventilación líquida parcial en adultos con lesión pulmonar aguda. Sin embargo, surge la pregunta del uso de los pfc asociados al surfactante artificial y de mayor número de estudios con grandes grupos comparativos. La pandemia ocasionada por el Covid-19 ha generalizado el uso de la ventilación mecánica en las unidades de cuidados intensivos. Conclusiones: La ventilación líquida con pfc es una realidad y constituye una nueva alternativa terapéutica para el manejo de los enfermos con síndrome de insuficiencia respiratoria aguda. Su uso con la ventilación líquida parcial no ha demostrado la utilidad esperada en adultos, que seguramente requerirán de la ventilación líquida total. En los neonatos con la ventilación líquida parcial existe ya suficiente evidencia para tenerla como una alternativa en los prematuros y el uso combinado con la administración de surfactante no se debe pasar por alto en los Hospitales de Perinatología a nivel mundial