Breeding ecology of Two-banded Plover (Charadrius falklandicus) in Valdés Peninsula, Argentina

Para desarrollar estrategias que mitiguen los impactos de la actividad humana sobre las poblaciones de aves playeras, es necesario conocer el estado de conservación de las especies. El estado de conservación de las especies de aves playeras endémicas del Neotrópico es poco entendido debido a la escasa información sobre el tamaño de las poblaciones, sus destinos migratorios y su ecología reproductiva. En este estudio investigamos la ecología reproductiva del Chorlo de Doble Collar (Charadrius falklandicus), un ave endémica del Neotrópico, en tres sitios de estudio en Chubut, Argentina. Nuestros resultados muestran que esta especie 1) se agrupa en hábitats de reproducción aunque presenta variación en los sitios donde construye los nidos, y 2) que el éxito de incubación disminuye al transcurrir la temporada y es menor que el éxito de crianza. El monitoreo de las aves anilladas, a largo plazo, permitirá investigar la fidelidad a la pareja y la fidelidad a los sitios de reproducción, así como los destinos migratorios durante el invierno austral. Esta información permitirá estimar parámetros demográficos para entender el estado de conservación de esta especie.Developing strategies to mitigate human impacts on shorebird populations require knowledge on the conservation status of shorebird species. The conservation status of endemic Neotropical species is poorly understood as information on population size, migratory movements and reproductive ecology is scanty. Here we investigate the breeding ecology of a Neotropical species, the Two-banded Plover (Charadrius falklandicus), in three study sites in Chubut, Argentina. We found 1) that this species aggregates in reproductive habitats despite presenting variation in nesting sites; and 2) that hatching success decreases with the date of the breeding season and is lower than fledging success. Long term monitoring of individually ringed birds will provide information on mate fidelity, breeding site fidelity, breeding success and migratory destinies during austral winter. This information will allow to estimate demographic parameters for a better understanding of the conservation status of this species.Fil: García Peña, Gabriel. E.. University of Bath; Reino UnidoFil: Hernández, María de Los Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Bala, Luis Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentin

Effect of temperature in bursting of thalamic reticular cells

Objective: To show the relation between the four parameters associated to bursting discharges of the thalamic reticular cells (TRNn): the maximum firing frequency (fmax) and the temperature at which it occurs (Tfmax), the range of temperatures defined as the full width at half maximum (∆Th) and the maximum specific low threshold calcium conductance (GT). Materials and Methods: In order to simulate the TRNn bursting activity a computational simulation model was implemented using the NEURON software, which incorporates morphological and electrophysiological data and stimuli properties closely related to reality. Results: It was found that there are nonlinear relations between the parameters. The fmax frequency follows a quadratic grow with temperature and tends asymptotically towards a limit value with the maximum calcium conductance.  In the same manner, ∆Th increases until reaching a limit value as function of fmax and GT. However, the increment per frequency unit is bigger than the increment per conductance unit. Conclusions: There were obtained four equations that model the relations between the parameters associated to bursting discharges of the TRNn in rats and other neurons with similar characteristics in different animal species

Mathematic Modelling of a Reversible Hydropower System: Dynamic Effects in Turbine Mode

Over the past few years, there has been significant interest in the importance of reversible hydro-pumping systems due to their favorable flexibility and economic and environmental characteristics. When designing reversible lines, it is crucial to consider dynamic effects and corresponding extreme pressures that may occur during normal and emergency operating scenarios. This research describes essentially the turbine operation, although various boundary elements are mathematically formulated and presented to provide an understanding of the system complexity. Different numerical approaches are presented, based on the 1D method of characteristics (MOC) for the long hydraulic circuit, the dynamic turbine runner simulation technique for the behavior of the power station in turbine mode and the interaction with the fluid in the penstock, and a CFD model (2D and 3D) to analyze the flow behavior crossing the runner through the velocity fields and pressure contours. Additionally, the simulation results have been validated by experimental tests on different setups characterized by long conveyance systems, consisting of a small scale of pumps as turbines (at IST laboratory) and classical reaction turbines (at LNEC laboratory). Mathematical models, together with an intensive campaign of experiments, allow for the estimation of dynamic effects related to the extreme transient pressures, the fluid-structure interaction with rotational speed variation, and the change in the flow. In some cases, the runaway conditions can cause an overspeed of 2–2.5 of the rated rotational speed (NR) and an overpressure of 40–65% of the rated head (HR), showing significant impacts on the pressure wave propagation along the entire hydraulic circuit. Sensitivity analyses based on systematic numerical simulations of PATs (radial and axial types) and reaction turbines (Francis and Kaplan types) and comparisons with experiments are discussed. These evaluations demonstrate that the full-load rejection scenario can be dangerous for turbomachinery with low specific-speed (ns) values, in particular when associated with long penstocks and fast guide vane (or control valve) closing maneuver. © 2023 by the authors

Numerical modelling for analysing drainage in irregular profile pipes using OpenFOAM

[EN] Different methods of two-dimensional and three-dimensional numerical resolution models have been used to predict the air¿water interaction in pipe systems in the early twenty-first century, where reliable and adequate results have been obtained when compared with experimental results. However, the study of the drainage process in pressurized systems with air admitted through openings has not been studied using this type of model due to the complexity that this represents. In this research, a two-dimensional numerical model is developed in the open-source software OpenFOAM; this model represents the drainage of an irregular pipe with air admitted by an air valve, defined by a structured mesh. A validation of the numerical model related to the air admitted by the variation of the air valve diameter is also performed.Paternina-Verona, DA.; Coronado-Hernández, OE.; Fuertes-Miquel, VS. (2022). Numerical modelling for analysing drainage in irregular profile pipes using OpenFOAM. Urban Water Journal. 19(6):569-578. https://doi.org/10.1080/1573062X.2022.205092956957819

Numerical modelling for analysing drainage in irregular profile pipes using OpenFOAM

Different methods of two-dimensional and three-dimensional numerical resolution models have been used to predict the air–water interaction in pipe systems in the early twenty-first century, where reliable and adequate results have been obtained when compared with experimental results. However, the study of the drainage process in pressurized systems with air admitted through openings has not been studied using this type of model due to the complexity that this represents. In this research, a two-dimensional numerical model is developed in the open-source software OpenFOAM; this model represents the drainage of an irregular pipe with air admitted by an air valve, defined by a structured mesh. A validation of the numerical model related to the air admitted by the variation of the air valve diameter is also performed. © 2022 Informa UK Limited, trading as Taylor & Francis Group

Hydropower Advantages over Batteries in Energy Storage of Off-Grid Systems: A Case Study

Microgrids are decentralized power production systems, where the energy production and consumption are very close to each other. Microgrids generally exploit renewable energy sources, encountering a problem of storage, as the power production from solar and wind is intermittent. This research presents a new integrated methodology and discusses a comparison of batteries and pumped storage hydropower (PSH) as energy storage systems with the integration of wind and solar PV energy sources, which are the major upcoming technologies in the renewable energy sector. We implemented the simulator and optimizer model (HOMER), which develops energy availability usage to obtain optimized renewable energy integration in the microgrid, showing its economic added value. Two scenarios are run with this model—one considers batteries as an energy storage technology and the other considers PSH—in order to obtain the best economic and technical results for the analyzed microgrid. The economic analysis showed a lower net present cost (NPC) and levelized cost of energy (LCOE) for the microgrid with PSH. The results showed that the microgrid with the storage of PSH was economical, with an NPC of 45.8 M€ and an LCOE of 0.379 €/kWh, in comparison with the scenario with batteries, which had an NPC of 95.2 M€ and an LCOE of 0.786 €/kWh. The role of storage was understood by differentiating the data into different seasons, using a Python model. Furthermore, a sensitivity analysis was conducted by varying the capital cost multiplier of solar PV and wind turbines to obtain the best optimal economic solutions

Music Self-Efficacy for Performance: An explanatory model based on Social Support

Personal perceptions of self-efficacy are particularly relevant in the field of music performance, which is oriented toward the outward expressions of one’s own ability through public performances. Within this context, a number of personal variables, including social support and performance anxiety, have been shown to be associated with musical success and are therefore relevant for research that seeks to understand the four sources of self-efficacy (mastery experiences, vicarious observation, verbal persuasion, physiological states) that are integral components of Bandura’s (2002) Social Learning Theory. Previous research, as well as observed differences among musicians associated with educational level (preuniversity) and gender (male/female), underpins the context of this study, which presents evidence regarding the factors that are capable of mediating perceptions of self-efficacy for musical performance. Specifically, the main objectives of this study were to more clearly understand relations between social support, public performance, musical performance anxiety, and self-efficacy using structural equation modeling and to compare these results according to gender. A battery of questionnaires was submitted to 359 preuniversity Spanish music students. Results highlight the relevance of family support for self-efficacy in public performance: directly and mediated through musical performance anxiety. The role of teachers and peers appeared to be relevant only for boys and was mediated through performance anxiety. Public performances lead to a greater degree of musical self-efficacy, but only in girls. Further research shall be required in order to improve pedagogical methods and help teachers increasingly individualize their teaching

Effect of a commercial air valve on the rapid filling of a single pipeline: a numerical and experimental analysis

[EN] The filling process in water pipelines produces pressure surges caused by the compression of air pockets. In this sense, air valves should be appropriately designed to expel sufficient air to avoid pipeline failure. Recent studies concerning filling maneuvers have been addressed without considering the behavior of air valves. This work shows a mathematical model developed by the authors which is capable of simulating the main hydraulic and thermodynamic variables during filling operations under the effect of the air valve in a single pipeline, which is based on the mass oscillation equation, the air¿water interface, the polytropic equation of the air phase, the air mass equation, and the air valve characterization. The mathematical model is validated in a 7.3-m-long pipeline with a 63-mm nominal diameter. A commercial air valve is positioned in the highest point of the hydraulic installation. Measurements indicate that the mathematical model can be used to simulate this phenomenon by providing good accuracy.This work is supported by Fundacao para a Ciencia e Tecnologia (FCT), Portugal (grant number PD/BD/114459/2016).Coronado-Hernández, OE.; Besharat, M.; Fuertes-Miquel, VS.; Ramos, HM. (2019). Effect of a commercial air valve on the rapid filling of a single pipeline: a numerical and experimental analysis. Water. 11(9):1-13. https://doi.org/10.3390/w11091814S11311

Chiral Mono- and α-Diimines and Their Pd(II) Complexes with Anticancer Activity

The aim of this review is to provide mainly an outlook of the synthesis and characterization of chiral mono- and α-diimines ligands and their Pd(II) complexes carried out in our group in the last few years. Some other issues with simple chiral imines synthesized in our lab are also outlined. The report includes details about their versatile coordination patterns, biological activity in cancer cell lines, and engaging properties in different fields, such as materials science

A Multi-Disciplinary Approach to Remote Sensing through Low-Cost UAVs

The use of Unmanned Aerial Vehicles (UAVs) based on remote sensing has generated low cost monitoring, since the data can be acquired quickly and easily. This paper reports the experience related to agave crop analysis with a low cost UAV. The data were processed by traditional photogrammetric flow and data extraction techniques were applied to extract new layers and separate the agave plants from weeds and other elements of the environment. Our proposal combines elements of photogrammetry, computer vision, data mining, geomatics and computer science. This fusion leads to very interesting results in agave control. This paper aims to demonstrate the potential of UAV monitoring in agave crops and the importance of information processing with reliable data flow.We wish to acknowledge the Consejo Nacional de Ciencia y Tecnologia (CONACYT) for its financial support to the PhD studies of Gabriela Calvario. We are grateful to Cubo Geoespacial S.A .de C.V. and special to Ing. Jordan Martinez for the stimulus to this work, more information about this Company is available at: http://www.cubogeoespacial.com/. In addition, we are grateful to the support of the Tequila Regulatory Council (CRT), which has allowed us to monitor several crops. This paper has been supported by the Spanish Ministerio de Economia y Competitividad, contract TIN2015-64395-R (MINECO/FEDER, UE), as well as by the Basque Government, contract IT900-16. This work was also supported in part by CONACYT (Mexico), Grant 258033