Impacts of land abandonment and climate variability on runoff generation and sediment transport in the Pisuerga headwaters (Cantabrian Mountains, Spain)

Producción CientíficaThe Atlantic mountains of Spain are suffering a strong landscape change due to a widespread and intensive emigration to urban areas since the 1950s. This process, representative of global developments in an imminent future, is dominated by urban societies and leads to deep landscape changes in which crop fields and grasslands are abandoned and progressively covered by forest and shrubs. These dynamics have caused in turn a decrease in the runoff and a general slowdown of geomorphological processes. The impacts of land cover change have been simultaneous to an irregularity in precipitation and a significant increase of temperatures. With this background, this paper assesses in detail the impact of landscape change occurred over the last decades (twentieth and twenty-first centuries) on the water and sediment yield in the Pisuerga catchment headwaters (Cantabrian Mountains, N Spain). We analyzed the different components of Global Change in a catchment of 233 km2 extent, that has passed from 15 to 2 habitants/km2, from multiple data sources. Evolution of land cover was reconstructed from aerial photographs, remote sensing and other resources. The climatic parameters have been studied through meteorological stations, and the hydrological and sedimentological responses over time are based on available runoff data and sedimentological analysis. Our results show a significant decrease in water and sediment transport mainly driven by vegetation increase occurred in a non-linear way, more intense immediately after abandonment. This fact opens the opportunity to control more accurately water resources in Mediterranean catchments through land use management.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project CGL2015-68144-R)Ministerio de Educación y Formación Profesional (grant FPU13/05837

A theory of electron collection by a grid sphere

Use of a spherical grid as electron collector at the anodic end of a tether, as recently proposed, is considered. The standard analysis of space-charge limited current to a solid sphere (with neither magnetic nor plasma-motion effects), which has been shown to best fit TSS1R in-orbit results at very high bias, is used to determine effects from grid transparency on current collected; the analysis is first reformulated in the formalism recently introduced in the two-dimensional analysis of bare-tethers. A discussion of the electric potential created by a spherical grid in vacuum is then carried out; it is shown that each grid-wire collects current well below its maximum OML current, the effective grid transparency being close to its optical value. Formulae for the current to a spherical grid, showing the effects of grid transparency, is determined. A fully consistent analysis of electric potential and electron density, outside and inside the grid, is completed

F-MPJ: scalable Java message-passing communications on parallel systems

This is a post-peer-review, pre-copyedit version of an article published in The Journal of Supercomputing. The final authenticated version is available online at: https://doi.org/10.1007/s11227-009-0270-0[Abstract] This paper presents F-MPJ (Fast MPJ), a scalable and efficient Message-Passing in Java (MPJ) communication middleware for parallel computing. The increasing interest in Java as the programming language of the multi-core era demands scalable performance on hybrid architectures (with both shared and distributed memory spaces). However, current Java communication middleware lacks efficient communication support. F-MPJ boosts this situation by: (1) providing efficient non-blocking communication, which allows communication overlapping and thus scalable performance; (2) taking advantage of shared memory systems and high-performance networks through the use of our high-performance Java sockets implementation (named JFS, Java Fast Sockets); (3) avoiding the use of communication buffers; and (4) optimizing MPJ collective primitives. Thus, F-MPJ significantly improves the scalability of current MPJ implementations. A performance evaluation on an InfiniBand multi-core cluster has shown that F-MPJ communication primitives outperform representative MPJ libraries up to 60 times. Furthermore, the use of F-MPJ in communication-intensive MPJ codes has increased their performance up to seven times.Ministerio de Educación y Ciencia; TIN2004-07797-C02Ministerio de Educación y Ciencia; TIN2007-67537-C03-2Xunta de Galicia; PGIDIT06PXIB105228P

A correction to Whipple's law for ion-trap Current

We have analyzed a phenomenon heretofore ignored in the analyses of ion traps, which are used to determine ion temperature, among other plasma parameters, in planetary ionospheres: ions that are rejected by the trap perturb the plasma well ahead of the Debye sheath at the front of the trap.The determination of the perturbed plasma flow is found to depend on the fact that the ionospheric plasma be stable to quasineutral, ion-acoustic perturbations

A generic, hard transition to chaos

A hard-in-amplitude transition to chaos in a class of dissipative flows of broad applicability is presented. For positive values of a parameter F, no matter how small, a fully developed chaotic attractor exists within some domain of additional parameters, whereas no chaotic behavior exists for F < 0. As F is made positive, an unstable fixed point reaches an invariant plane to enter a phase half-space of physical solutions; the ghosts of a line of fixed points and a rich heteroclinic structure existing at F = 0 make the limits t --* +oc, F ~ +0 non-commuting, and allow an exact description of the chaotic flow. The formal structure of flows that exhibit the transition is determined. A subclass of such flows (coupled oscillators in near-resonance at any 2 : q frequency ratio, with F representing linear excitation of the first oscillator) is fully analyse

Prevalence and factors associated with SARS-CoV-2 seropositivity in the Spanish HIV Research Network Cohort

"Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAM"Objectives: We aimed to assess the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and factors associated with seropositivity and asymptomatic coronavirus disease 2019 (COVID-19) among people with HIV (PWH). Methods: This was a cross-sectional study carried out within the cohort of the Spanish HIV Research Network. Participants were consecutive PWH with plasma collected from 1st April to 30th September 2020. We determined SARS-CoV-2 antibodies (Abs) in plasma. Illness severity (NIH criteria) was assessed by a review of medical records and, if needed, participant interviews. Multivariable logistic regression analysis was used to identify predictors of seropositivity among the following variables: sex, age, country of birth, education level, comorbidities (hypertension, chronic heart disease, diabetes mellitus, non-AIDS-related cancer, chronic kidney disease, cirrhosis), route of HIV acquisition, prior AIDS, CD4+ cell count, HIV viral load, nucleoside/nucleotide reverse transcriptase inhibitor (N [t]RTI) backbone, type of third antiretroviral drug, and month of sample collection. Results: Of 1076 PWH (88.0% males, median age 43 years, 97.7% on antiretroviral therapy, median CD4+ 688 cells/mm3, 91.4% undetectable HIV viral load), SARS-CoV-2 Abs were detected in 91 PWH, a seroprevalence of 8.5% (95%CI 6.9–10.3%). Forty-five infections (45.0%) were asymptomatic. Variables independently associated with SARS-CoV-2 seropositivity were birth in Latin American countries versus Spain (adjusted odds ratio (aOR) 2.30, 95%CI 1.41–3.76, p 0.001), and therapy with tenofovir disoproxil fumarate plus emtricitabine (TDF/FTC) versus tenofovir alafenamide (TAF)/FTC as the N(t)RTI backbone (aOR 0.49, 95%CI 0.26–0.94, p 0.031). Conclusions: Many SARS-CoV-2 infections among PWH were asymptomatic, and birth in Latin American countries increased the risk of SARS-CoV-2 seropositivity. Our analysis, adjusted by comorbidities and other variables, suggests that TDF/FTC may prevent SARS-CoV-2 infection among PWH.This work was supported by the Instituto de Salud Carlos III (ISCII) (grant number COV20/00108) and the Spanish AIDS Research Network (RD16/0025), which is included in the Spanish I þ D þ I Plan and is co-funded by ISCIII-Subdirección General de Evaluacion and European Funding for Regional Development (FEDER)

Sistemas de Producción Agrosilvopastoril de la “Quinta El Quiosco”

El presente ensayo muestra un análisis del sistema de producción tipo silvopastoril de la unidad productiva llamada “Quinta el Quiosco. El objetivo fue evaluar diferentes aspectos del sistema de producción y la relación entre los componentes del sistema, calcular el aporte económico obtenido, y detectar el rol y la integración de la mujer como generadora de ingresos y finalmente algunas alternativas propuestas por el productor antes los cambios en el clima. Metodológicamente se aplicó un diagnóstico de sistemas de producción usando la técnica de análisis documental y visitas de campo. Se encontró que la unidad productiva muestra un Sistema Agrosilvopastoril urbano con cierto grado de coherencia interna que genera suficientes ingresos para la manutención de la familia Lezama. La integración de la mujer es notoria en este sistema como generadora de ingresos y sustento del hogar. La variabilidad climática presentada en los últimos años conllevo al productor a tomar medidas alternas para contrarrestar los efectos ambientales en su producció

A solution for tracking visitors in Smart Shopping environments: A real platform implementation based on Raspberry Pi

In parallel to the explosion of the use of wireless technologies to connect devices, the scientific community is continually aiming to take advantage of such technologies to provide new services. In this sense, there have been many attempts to exploit the information provided by IEEE802.11 and Bluetooth interfaces, commonly found in most of the smartphones that are being used at the time of writing. In this paper we describe a novel deployment that fosters such approach. Furthermore, the measurements that are gathered are made available, thanks to its integration within the SmartSantander testbed, and to the federation with complementary testbeds. The federation platform and the described deployment are outcomes of the FESTIVAL collaborative project (Europe-Japan). Besides depicting the corresponding software architecture, the paper also discusses some preliminary results that are used to assess the feasibility of the proposed scheme.This work was funded in part by the European Union’s Horizon 2020 Programme of the FESTIVAL project (Federated Interoperable Smart ICT Services Development and Testing Platforms) under grant agreement 643275, and from the Japanese National Institute of Information and Communications Technology. This work has been also supported by the Spanish Government (Ministerio de Economía y Competitividad, Fondo Europeo de Desarrollo Regional, FEDER) by means of the project ADVICE (TEC2015-71329-C2-1-R)

Impact of social metrics in decentralized finance

In our study, we have evaluated the impact of tweets, social indicators, uncertainty, and attention indices on the selected variables calculated from a pool of 51 decentralised finance entities. In so doing, we have identified some evidence that returns are impacted by tweets, but not by social indicators that appear to be more relevant for volatility. We have further confirmed that the S&P500 Index negatively influences cryptocurrency returns, which means that these two asset classes are substitutes. Uncertainty and attention indices are relevant in determining returns and the alternative measurement of volatility. However, they remain insignificant for illiquidity and our initial volatility choiceS

Hierarchical Self-Organization from Cyclic Peptide

The 19th International Electronic Conference on Synthetic Organic Chemistry session Polymer and Supramolecular ChemistryOur research group is implicated on the design and synthesis of supramolecular structures based on self-assembling cyclic peptides, particularly alpha,gamma-cyclic peptides (CPs). Most of these structures: dimer, nanotubes, fiber, etc, are based on beta-sheet type interactions. The CPs form structures that have allowed preparing a large variety of structures with applications in ion channels, electron and energy transfer process, molecular tweezers and so on. Here, we present the formation of spheres, hollow spheres, fibers, bars, etc. by a hierarchical supramolecular process from alpha,gamma-cyclic peptides with pyridine derivate ligands attached to one of its side chains, that additionally, are able to coordinate metals (Cu, Pd, etc.), entrap molecules, etc. which give to these structures a great potential for catalysis and drug deliver