Coordination and Miss-Coordination in Market Entry Games with an Application to Congestion Externalities

Marketing,

Palatini wormholes and energy conditions from the prism of General Relativity

Wormholes are hypothetical shortcuts in spacetime that in General Relativity unavoidably violate all of the pointwise energy conditions. In this paper, we consider several wormhole spacetimes that, as opposed to the standard \emph{designer} procedure frequently employed in the literature, arise directly from gravitational actions including additional terms resulting from contractions of the Ricci tensor with the metric, and which are formulated assuming independence between metric and connection (Palatini approach). We reinterpret such wormhole solutions under the prism of General Relativity and study the matter sources that thread them. We discuss the size of violation of the energy conditions in different cases, and how this is related to the same spacetimes when viewed from the modified gravity side.Comment: 13 pages, 7 figures. Significant changes mainly in introduction and conclusions. Accepted for publication in Eur. Phys. J.

Dilaton thin-shell wormholes supported by a generalized Chaplygin gas

In this article, we construct spherical thin-shell wormholes with charge in dilaton gravity. The exotic matter required for the construction is provided by a generalized Chaplygin gas. We study the stability under perturbations preserving the symmetry. We find that the increase of the coupling between the dilaton and the electromagnetic fields reduces the range of the parameters for which stable configurations are possible.Comment: 14 pages, 6 figures. v3: typos correcte

High-Resolution Dynamics of Hydrogen Peroxide on the Surface of Scleractinian Corals in Relation to Photosynthesis and Feeding

We developed and used a microsensor to measure fast (<1 s) dynamics of hydrogen peroxide (H2O2) on the polyp tissue of two scleractinian coral species (Stylophora pistillata and Pocillopora damicornis) under manipulations of illumination, photosynthesis, and feeding activity. Our real-time tracking of H2O2 concentrations on the coral tissue revealed rapid changes with peaks of up to 60 mu M. We observed bursts of H2O2 release, lasting seconds to minutes, with rapid increase and decrease of surficial H2O2 levels at rates up to 15 mu M s(-1). We found that the H2O2 levels on the polyp surface are enhanced by oxygenic photosynthesis and feeding, whereas H2O2 bursts occurred randomly, independently from photosynthesis. Feeding resulted in a threefold increase of baseline H2O2 levels and was accompanied by H2O2 bursts, suggesting that the coral host is the source of the bursts. Our study reveals that H2O2 levels at the surface of coral polyps are much higher and more dynamic than previously reported, and that bursts are a regular feature of the H2O2 dynamics in the coral holobiont

Assessing the relative accuracy of coral heights reconstructed from drones and structure from motion photogrammetry on coral reefs

Low-altitude high-resolution aerial photographs allow for the reconstruction of structural properties of shallow coral reefs and the quantification of their topographic complexity. This study shows the scope and limitations of two-media (air/water) Structure from Motion—Multi-View Stereo reconstruction method using drone aerial photographs to reconstruct coral height. We apply this method in nine different sites covering a total area of about 7000 m2, and we examine the suitability of the method to obtain topographic complexity estimates (i.e., seafloor rugosity). A simple refraction correction and survey design allowed reaching a root mean square error of 0.1&nbsp;m for the generated digital models of the seafloor (without the refraction correction the root mean square error was 0.2&nbsp;m). We find that the complexity of the seafloor extracted from the drone digital models is slightly underestimated compared to the one measured with a traditional in situ survey method

Optimization of refinery preheat trains: predictive maintenance and operations improvement

Deciding which heat exchanger to clean, when to clean and how to clean in refinery pre-heat trains is a challenging activity that typically relies on operator’s experience. In this paper, an algorithm that allow identifying the most economic cleaning schedule for a given refinery configuration and operating conditions is presented. The method relies on an advanced framework that incorporates rigorous heat exchanger models capable of predicting the fouling behaviour of the refinery as a function of configuration of the individual units and the network, process conditions and time. An industrial case study is presented to illustrate the benefits of the approach, showing that significant improvements over current practice can be obtained

Electrification of the boat fleet of the Albufera Natural Park of Valencia: methodology, economic and environmental assessments

[EN] This article presents a methodology for calculating the energy needs to propose the electrification of a fleet of small boats. A technical, economic and environmental analysis of the transition to electric mobility of the fleet of boats in the wetland of the Albufera Natural Park of Valencia (Spain) is presented and analysed. The environmental benefits of this transition are explored and an economic assessment is done, including the evaluation of the necessary public incentives to capture all the benefits related to this transition and make it feasible.This work was supported in part by the Spanish public administration under the grant FPU2016/00962 and by the Cátedra de Transición Energética Urbana (Las Naves-UPV).Bejarano-Cáceres, DS.; Ribó-Pérez, DG.; Alcázar-Ortega, M. (2020). Electrification of the boat fleet of the Albufera Natural Park of Valencia: methodology, economic and environmental assessments. Renewable Energy and Power Quality Journal. 18:144-149. https://doi.org/10.24084/repqj18.254S1441491

The perception of indole negatively modulates biocontrol activities in the plant beneficial Rhizobacterium Lysobacter capsici AZ78

The rhizosphere is a dynamic environment characterised by multiple and complex microbial interactions where diffusible communication signals (DCS) continuously influence the expression patterns of the microbiome, hence regulating fundamental traits for adaptation to the rhizosphere. In particular, plant-associated bacteria release indole, a Volatile Organic Compound (VOC) that acts as an interkingdom signal able to influence antibiotic resistance, motility, biofilm formation and virulence. Lysobacter spp. are commonly found in the rhizosphere and have been frequently associated to disease suppression. For instance, the biocontrol activity of the plant beneficial bacterium Lysobacter capsici AZ78 (AZ78) has been reported against the phytopathogenic oomycetes Phytophthora infestans, Plasmopara viticola, Pythium ultimum and the Gram-positive bacterium Rhodococcus fascians. However, there is scarce information about Lysobacter spp. ecology and how DCS, and in particular indole, may affect their behaviour in the rhizosphere. To investigate the aspects determining rhizosphere competence and functioning of Lysobacter spp., this work presents a functional and transcriptomic analysis performed on AZ78, which was grown in the presence indole. The presence of indole significantly reduced the inhibition capacity of AZ78 against P. ultimum and R. fascians by 47 and 31%, respectively. Moreover, RNA-Seq analysis revealed that nearly 12% of all genes in AZ78 genome were modulated by indole. In particular, indole downregulated the expression of the heat-stable antifungal factor (HSAF) biosynthetic gene cluster, which may affect AZ78 antioomycete and antimicrobial activity. Moreover, in the presence of indole, AZ78 downregulated several signal transduction pathways responsible for nutrients uptake, resulting in reduced growth. Finally, indole downregulated several genes related to type IV pilus functionality, which might lead to impaired twitching motility. This study sheds light on the key role of DCS such as indole in shaping AZ78 behaviour in the rhizosphere and suggests that, manipulating DCS levels may alter the persistence and functioning of several plant-beneficial rhizobacteria, such as Lysobacter strains

Un Camino Solitario! / A Lonely Road!: Chicana/o Faculty Storytelling and Counterstorytelling in Academia

This volume brings together the latest research and scholarship on Latinos in the United States. This book is special in terms of the broad scope of topics covered and methodologies employed in pursuit of knowledge about Latino students. This collection is also unique in that it features the work of more than a dozen Latino scholars”both early-career and established”applying their research expertise to investigate and elucidate the educational experiences of Latinos in the United States. The themes that are discussed in the chapters of The Education of the Hispanic Population: Selected Essays, reflect the wide-ranging discussions that are occurring in schools and school districts across the country and issues that are being carefully investigated by researchers who are committed to contributing thoughtful and meaningful scholarship of consequence for improving conditions for Latino youth