Métodos para evaluar interacciones entre cuerpos de agua en un humedal y aplicación en dos casos de estudio

La comprensión de la dinámica de ecosistemas dependientes del recurso hídrico subterráneo, como pueden llegar a serlo algunos humedales, parte del conocimiento del sistema hidrológico. Para alcanzar esta meta se aplica una serie de métodos y procedimientos de análisis que comprenden la caracterización hi-drogeológica, la delimitación del área de captura de agua hacia el humedal, el monitoreo piezométrico, la rea-lización de balances de masas. La modelación numérica, los análisis hidrogeoquímicos y los métodos isotópi-cos permiten refinar y validar los modelos conceptuales. En el marco del proyecto Hydrochemical and isotopic techniques for assessment hidrological proccesses on wetlands, promovido entre los años 2006 y 2011 por la Agencia Internacional de Energía Atómica (IAEA), Colombia y Argentina compartieron conoci-miento y experiencias para entender la dinámica de los humedales Ciénaga Colombia y La Salada. En este texto se resumen aspectos metodológicos y los resultados de los dos casos de estudio considerados.The Understanding of ecosystem dynamics, for example the wetlands, depends of the knowledge of the hydrologic system. Many techniques can be used in order to obtain a good conceptual mod-el of the wetlands and its catchment area: hydrogeology, numerical modeling, hydrogeochemestry, and iso-tope hydrology. researchers of Argentina and Colombia studied -According with the project: ―Hydrochemical and isotopic techniques for assessment hidrological proccesses on wetlands‖ (IAEA, 2006 to 2011)- two wet-lands hydrogeology dependent: La salada Pond and Cienaga Colombia Weltand. These projects used method-ologies similar and they obtained validated hydrological models

Planetary Radio Interferometry and Doppler Experiment (PRIDE) Technique: a Test Case of the Mars Express Phobos Fly-by. 2. Doppler tracking: Formulation of observed and computed values, and noise budget

Context. Closed-loop Doppler data obtained by deep space tracking networks (e.g., NASA's DSN and ESA's Estrack) are routinely used for navigation and science applications. By "shadow tracking" the spacecraft signal, Earth-based radio telescopes involved in Planetary Radio Interferometry and Doppler Experiment (PRIDE) can provide open-loop Doppler tracking data when the dedicated deep space tracking facilities are operating in closed-loop mode only. Aims. We explain in detail the data processing pipeline, discuss the capabilities of the technique and its potential applications in planetary science. Methods. We provide the formulation of the observed and computed values of the Doppler data in PRIDE tracking of spacecraft, and demonstrate the quality of the results using as a test case an experiment with ESA's Mars Express spacecraft. Results. We find that the Doppler residuals and the corresponding noise budget of the open-loop Doppler detections obtained with the PRIDE stations are comparable to the closed-loop Doppler detections obtained with the dedicated deep space tracking facilities

Caracterización preliminar de las interacciones aguas subterráneas-humedales-ser humano en Iberoamérica y en la Península Ibérica

El proyecto UNESCO IGCP 604 tiene como objetivo elaborar un marco conceptual sobre las interacciones aguas subterráneas–humedales-ser humano, y está motivado por el Programa de Evaluación de los Ecosistemas del Milenio de Naciones Unidas. Como resultados preliminares se ha elaborado información de catorce humedales en nueve países. Sus características morfológicas, hidrológicas, químicas, etc. son muy variables. Solamente los servicios de abastecimiento de agua y de regulación hídrica parecen estar ampliamente extendidos, con una tendencia dominante a mantenerse estables o a empeorar. Todos los servicios culturales son frecuentes y muestran una tendencia mayoritaria a mejorar. Entre los factores que inducen cambios en los servicios, los de impacto más extendido son: extracción de agua, cambios en el uso de suelo, contaminación y cambio climático y global. Presentan impactos variables, pero la tendencia general es a mantenerse estables o a aumentar.This paper presents the preliminary results of The UNESCO project IGCP 604, whose objec-tive is to elaborate a conceptual framework on groundwater-wetland-human beings interactions, and is moti-vated by the UNESCO Millennium Ecosystems Assessment Programme. Data from fourteen wetlands in nine countries have been elaborated. Their morphological, hydrological, chemical, etc. characteristics are highly variable. Only the water supply and water regulation services seem to be widely extended, and their general evolution trend is to be stable or to worsen. All the cultural services seem to be widely extended, and the dominant trend is to improve. The factors that most widely induce changes in wetland services are water ex-traction, biological exploitation, changes in land use, pollution, and climate and global change. They cause variable impacts, which tend to be stable or to increase

Venus Express radio occultation observed by PRIDE

Context. Radio occultation is a technique used to study planetary atmospheres by means of the refraction and absorption of a spacecraft carrier signal through the atmosphere of the celestial body of interest, as detected from a ground station on Earth. This technique is usually employed by the deep space tracking and communication facilities (e.g., NASA's Deep Space Network (DSN), ESA's Estrack). Aims. We want to characterize the capabilities of the Planetary Radio Interferometry and Doppler Experiment (PRIDE) technique for radio occultation experiments, using radio telescopes equipped with Very Long Baseline Interferometry (VLBI) instrumentation. Methods. We conducted a test with ESA's Venus Express (VEX), to evaluate the performance of the PRIDE technique for this particular application. We explain in detail the data processing pipeline of radio occultation experiments with PRIDE, based on the collection of so-called open-loop Doppler data with VLBI stations, and perform an error propagation analysis of the technique. Results. With the VEX test case and the corresponding error analysis, we have demonstrated that the PRIDE setup and processing pipeline is suited for radio occultation experiments of planetary bodies. The noise budget of the open-loop Doppler data collected with PRIDE indicated that the uncertainties in the derived density and temperature profiles remain within the range of uncertainties reported in previous Venus' studies. Open-loop Doppler data can probe deeper layers of thick atmospheres, such as that of Venus, when compared to closed-loop Doppler data. Furthermore, PRIDE through the VLBI networks around the world, provides a wide coverage and range of large antenna dishes, that can be used for this type of experiments

Analysis of an Interplanetary Coronal Mass Ejection by a spacecraft radio signal: A case study

Tracking radio communication signals from planetary spacecraft with ground-based telescopes offers the possibility to study the electron density and the interplanetary scintillation of the solar wind. Observations of the telemetry link of planetary spacecraft have been conducted regularly with ground antennae from the European Very Long Baseline Interferometry Network, aiming to study the propagation of radio signals in the solar wind at different solar elongations and distances from the Sun. We have analyzed the Mars Express spacecraft radio signal phase fluctuations while, based on a 3-D heliosphere plasma simulation, an interplanetary coronal mass ejection (ICME) crossed the radio path during one of our observations on 6 April 2015. Our measurements showed that the phase scintillation indices increased by a factor of 4 during the passage of the ICME. The method presented here confirms that the phase scintillation technique based on spacecraft signals provides information of the properties and propagation of the ICMEs in the heliosphere

Dynamic constriction and fission of endoplasmic reticulum membranes by reticulon

The endoplasmic reticulum (ER) is a continuous cell-wide membrane network. Network formation has been associated with proteins producing membrane curvature and fusion, such as reticulons and atlastin. Regulated network fragmentation, occurring in different physiological contexts, is less understood. Here we find that the ER has an embedded fragmentation mechanism based upon the ability of reticulon to produce fission of elongating network branches. In Drosophila, Rtnl1-facilitated fission is counterbalanced by atlastin-driven fusion, with the prevalence of Rtnl1 leading to ER fragmentation. Ectopic expression of Drosophila reticulon in COS-7 cells reveals individual fission events in dynamic ER tubules. Consistently, in vitro analyses show that reticulon produces velocity-dependent constriction of lipid nanotubes leading to stochastic fission via a hemifission mechanism. Fission occurs at elongation rates and pulling force ranges intrinsic to the ER, thus suggesting a principle whereby the dynamic balance between fusion and fission controlling organelle morphology depends on membrane motility

QRTEngine: An easy solution for running online reaction time experiments using Qualtrics

Performing online behavioral research is gaining increased popularity among researchers in psychological and cognitive science. However, the currently available methods for conducting online reaction time experiments are often complicated and typically require advanced technical skills. In this article, we introduce the Qualtrics Reaction Time Engine (QRTEngine), an open-source JavaScript engine that can be embedded in the online survey development environment Qualtrics. The QRTEngine can be used to easily develop browser-based online reaction time experiments with accurate timing within current browser capabilities, and it requires only minimal programming skills. After introducing the QRTEngine, we briefly discuss how to create and distribute a Stroop task. Next, we describe a study in which we investigated the timing accuracy of the engine under different processor loads using external chronometry. Finally, we show that the QRTEngine can be used to reproduce classic behavioral effects in three reaction time paradigms: a Stroop task, an attentional blink task, and a masked-priming task. These findings demonstrate that QRTEngine can be used as a tool for conducting online behavioral research even when this requires accurate stimulus presentation times

A monitoring campaign (2013-2020) of ESA's Mars Express to study interplanetary plasma scintillation

The radio signal transmitted by the Mars Express (MEX) spacecraft was observed regularly between the years 2013-2020 at X-band (8.42 GHz) using the European Very Long Baseline Interferometry (EVN) network and University of Tasmania's telescopes. We present a method to describe the solar wind parameters by quantifying the effects of plasma on our radio signal. In doing so, we identify all the uncompensated effects on the radio signal and see which coronal processes drive them. From a technical standpoint, quantifying the effect of the plasma on the radio signal helps phase referencing for precision spacecraft tracking. The phase fluctuation of the signal was determined for Mars' orbit for solar elongation angles from 0 - 180 deg. The calculated phase residuals allow determination of the phase power spectrum. The total electron content (TEC) of the solar plasma along the line of sight is calculated by removing effects from mechanical and ionospheric noises. The spectral index was determined as $-2.43 \pm 0.11$ which is in agreement with Kolomogorov's turbulence. The theoretical models are consistent with observations at lower solar elongations however at higher solar elongation ($>$160 deg) we see the observed values to be higher. This can be caused when the uplink and downlink signals are positively correlated as a result of passing through identical plasma sheets.Comment: The paper has 13 figures and one table. It has been accepted for publication in PASA and the article will receive its DOI in a week's tim

An Open-Source Social Robot Based on Compliant Soft Robotics for Therapy with Children with ASD

Therapy with robotic tools is a promising way to help improve verbal and nonverbal communication in children. The robotic tools are able to increase aspects such as eye contact and the ability to follow instructions and to empathize with others. This work presents the design methodology, development, and experimental validation of a novel social robot based on CompliAnt SofT Robotics called the CASTOR robot, which intends to be used as an open-source platform for the long-term therapy of children with autism spectrum disorder (CwASD). CASTOR integrates the concepts of soft actuators and compliant mechanisms to create a replicable robotic platform aimed at real therapy scenarios involving physical interaction between the children and the robot. The validation shows promising results in terms of robustness and the safety of the user and robot. Likewise, mechanical tests assess the robot’s response to blocking conditions for two critical modules (i.e., neck and arm) in interaction scenarios. Future works should focus on the validation of the robot’s effectiveness in the therapy of CwASD.</jats:p