88 research outputs found

    The Rücker–Markov invariants of complex bio-systems: applications in parasitology and neuroinformatics

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    [Abstract] Rücker's walk count (WC) indices are well-known topological indices (TIs) used in Chemoinformatics to quantify the molecular structure of drugs represented by a graph in Quantitative structure–activity/property relationship (QSAR/QSPR) studies. In this work, we introduce for the first time the higher-order (kth order) analogues (WCk) of these indices using Markov chains. In addition, we report new QSPR models for large complex networks of different Bio-Systems useful in Parasitology and Neuroinformatics. The new type of QSPR models can be used for model checking to calculate numerical scores S(Lij) for links Lij (checking or re-evaluation of network connectivity) in large networks of all these fields. The method may be summarized as follows: (i) first, the WCk(j) values are calculated for all jth nodes in a complex network already created; (ii) A linear discriminant analysis (LDA) is used to seek a linear equation that discriminates connected or linked (Lij = 1) pairs of nodes experimentally confirmed from non-linked ones (Lij = 0); (iii) The new model is validated with external series of pairs of nodes; (iv) The equation obtained is used to re-evaluate the connectivity quality of the network, connecting/disconnecting nodes based on the quality scores calculated with the new connectivity function. The linear QSPR models obtained yielded the following results in terms of overall test accuracy for re-construction of complex networks of different Bio-Systems: parasite–host networks (93.14%), NW Spain fasciolosis spreading networks (71.42/70.18%) and CoCoMac Brain Cortex co-activation network (86.40%). Thus, this work can contribute to the computational re-evaluation or model checking of connectivity (collation) in complex systems of any science field.Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo; Ibero-NBIC, 209RT-0366Ministerio de Ciencia e Innovación; TIN2009-0770

    Biomass and primary production of a 8-11 m depth meadow versus <3 m depth meadows of the seagrass Cymodocea nodosa (Ucria) Ascherson

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    Current knowledge about the abundance, growth, and primary production of the seagrass Cymodocea nodosa (Ucria) Ascherson is biased towards shallow (depth <3 m) meadows although this species also forms extensive meadows at larger depths along the coastlines. The biomass and primary production of a C. nodosa meadow located at a depth of 8-11 m was estimated at the time of maximum annual vegetative development (summer) using reconstruction techniques, and compared with those available from shallow meadows of this species. A depth-referenced data base of values at the time of maximum annual development was compiled to that end. The vegetative development of C. nodosa at 8-11 m depth was not different from that achieved by shallow (depth <3 m) meadows of this species. Only shoot density, which decreased from 1637 to 605 shoots m-2, and the annual rate of elongation of the horizontal rhizome, which increased from 23 to 71 cm apex-1 year-1, were different as depth increased from <3 to 8-11 m. Depth was a poor predictor of the vegetative development and primary production of C. nodosa. The biomass of rhizomes and roots decreased with depth (g DW m-2 = 480 (±53, S.E.) - 32 (±15, S.E.) depth (in m); R2 = 0.12, F = 4.65, d.f. = 35, P = 0.0381) which made total biomass of the meadow to show a trend of decrease with depth but the variance of biomass data explained by depth was low. The annual rate of elongation of the horizontal rhizome showed a significant positive relationship with depth (cm apex-1 year-1 = 18 (±5.1, S.E.) + 5.0 (±1.33, S.E.) depth (in m); R2 = 0.50, F = 14.07, d.f. = 14, P = 0.0021). As shoot size and growth did not change significantly with depth, the reduction of shoot density should drive any changes of biomass and productivity of C. nodosa as depth increases. The processes by which this reduction of C. nodosa abundance with depth occur remain to be elucidated. © 2006 Elsevier B.V. All rights reserved.This study was funded by the Specific Programme “Energy, Environment and Sustainable Development” of the Fifth Framework Programme of the European Union (contract number EVK3-CT-2000-00044, Monitoring and Managing of European Seagrass Beds)Peer Reviewe

    Exposure to particulate matter: direct and indirect role in the COVID-19 pandemic

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    Knowing the transmission factors and the natural environment that favor the spread of a viral infection is crucial to stop outbreaks and develop effective preventive strategies. This work aims to evaluate the role of Particulate Matter (PM) in the COVID-19 pandemic, focusing especially on that of PM as a vector for SARS-CoV-2. Exposure to PM has been related to new cases and to the clinical severity of people infected by SARS-CoV-2, which can be explained by the oxidative stress and the inflammatory response generated by these particles when entering the respiratory system, as well as by the role of PM in the expression of ACE-2 in respiratory cells in human hosts. In addition, different authors have detected SARS-CoV-2 RNA in PM sampled both in outdoor and indoor environments. The results of various studies lead to the hypothesis that the aerosols emitted by an infected person could be deposited in other suspended particles, sometimes of natural but especially of anthropogenic origin, that form the basal PM. However, the viability of the virus in PM has not yet been demonstrated. Should PM be confirmed as a vector of transmission, prevention strategies ought to be adapted, and PM sampling in outdoor environments could become an indicator of viral load in a specific area.“This work has been carried out within the framework of the project “Air pollution and COVID-19: what can we learn from this pandemic?” of the Call for Grants from the BBVA Foundation to Scientific Research Teams in SARS-CoV-2 and COVID-19, in the area of Ecology and Veterinary Medicine

    Nuevas citas y aportaciones corológicas para la flora bentónica marina del Atlántico de la Península Ibérica

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    Se dan a conocer nuevas localizaciones y datos corológicos para 98 especies (61 Rhodophyta, 22 Ochrophyta, 15 Chlorophyta) de algas bentónicas marinas recolectadas en el intermareal y submareal de más de 80 localidades de las costas atlánticas y cantábricas de la Península Ibérica. Polysiphonia devoniensis, P. fibrata y Zonaria tournefortii son novedad para Portugal y 5 especies (Bonnemaisonia hamifera, Calosiphonia vermicularis, P. devoniensis, Hincksia intermedia y Derbesia marina stadium Halicystis ovalis) son nuevas citas para Galicia. Paralelamente, se aportan 101 primeras citas provinciales (2 Guipúzcoa, 1 Vizcaya, 8 Cantabria, 5 Asturias, 7 Lugo, 1 A Coruña, 8 Pontevedra, 1 Beira litoral, 15 Estremadura, 20 Alentejo, 25 Algarve y 8 Cádiz) y, además, se dan a conocer 108 segundas citas provinciales. Aunque la flora bentónica marina del Atlántico Peninsular ha sido objeto de numerosos estudios, estos nuevos hallazgos corológicos ponen en evidencia que todavía son necesarios más estudios florísticos en estas costa

    100 casos de derecho de daños (2004-2009)

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    InDret presenta, por sexto año consecutivo, una selección de veinte sentencias sobre responsabilidad civil dictadas por el Tribunal Supremo que tratan cuestiones centrales del derecho de daños. El lector también encontrará en este trabajo las selecciones de 2004, 2005, 2006, 2007 y 2008 publicadas en números anteriores.InDret publishes its sixth annual selection of tort cases decided by the Spanish Supreme Court. All selected cases dealt with central questions of the Law of Torts. We also provide the reader with InDret 2004, 2005, 2006, 2007 and 2008 selections

    40 casos de Derecho de daños (2004-2007)

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    InDret presenta, por sexto año consecutivo, una selección de veinte sentencias sobre responsabilidad civil dictadas por el Tribunal Supremo que tratan cuestiones centrales del derecho de daños. El lector también encontrará en este trabajo las selecciones de 2004, 2005, 2006, 2007 y 2008 publicadas en números anteriores.InDret publishes its sixth annual selection of tort cases decided by the Spanish Supreme Court. All selected cases dealt with central questions of the Law of Torts. We also provide the reader with InDret 2004, 2005, 2006, 2007 and 2008 selections

    Simulation of electron transport and secondary emission in a photomultiplier tube and experimental validation

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    [EN] The electron amplification and transport within a photomultiplier tube (PMT) has been investigated by developing an in-house Monte Carlo simulation code. The secondary electron emission in the dynodes is implemented via an effective electron model and the Modified Vaughan¿s model, whereas the transport is computed with the Boris leapfrog algorithm. The PMT gain, rise time and transit time have been studied as a function of supply voltage and external magnetostatic field. A good agreement with experimental measurements using a Hamamatsu R13408-100 PMT was obtained. The simulations have been conducted following different treatments of the underlying geometry: three-dimensional, two-dimensional and intermediate (2.5D). The validity of these approaches is compared. The developed framework will help in understanding the behavior of PMTs under highly intense and irregular illumination or varying external magnetic fields, as in the case of prompt gamma-ray measurements during pencil-beam proton therapy; and aid in optimizing the design of voltage dividers with behavioral circuit models.This work was supported by Conselleria de Educación, Investigación, Cultura y Deporte (Generalitat Valenciana) under grant numbers CDEIGENT/2019/011 and CDEIGENT/2021/012. P. Martín-Luna is supported by the Ministerio de Universidades (Gobierno de España), Spain under Grant Number FPU20/04958. We thank Hamamatsu (V. Sánchez, D. Castrillo) for technical support and guidance; R. Carrasco (IFIC) and P. Wohlfahrt (Siemens Healthineers) for the CT scanning; D. Calvo and D. Real (KM3net-IFIC) for their LED test platform, the electronics and maintenance services at IFIC for excellent support; and K. Albiol, J. V. Casaña-Copado, A. Gallas Torreira, E. Lemos Cid, G. Pausch, A. Pazos Álvarez, E. Pérez Trigo, S. Rit, A. Ros, J. Roser, J. Stein, J. L. Taín and R. Viegas for useful discussions.Martín-Luna, P.; Esperante, D.; Fernández Prieto, A.; Fuster-Martínez, N.; García Rivas, I.; Gimeno, B.; Ginestar Peiro, D.... (2024). Simulation of electron transport and secondary emission in a photomultiplier tube and experimental validation. Sensors and Actuators A Physical. 365:1-10. https://doi.org/10.1016/j.sna.2023.11485911036

    Towards a holistic understanding of pastoralism

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    Pastoralism is a globally-important livelihood, with large social, environmental and economic importance across much of our planet. Yet, it is also a vulnerable practice with widespread crises, urgently calling for better systemic understanding. The current disciplinary compartmentalization of research not only hampers this but allows perpetuation of unfortunate misconceptions. Furthermore, a long-standing marginalization of the livelihood prevails, with pastoralism being largely overlooked in international environmental and economic forums or sustainability agendas. Here we call for transformative approaches to pastoralism research that can advance an integrated understanding of these social-ecological systems through a comparative lens. We develop a framework that uses: i) timescales from the distant past to the present, ii)social, economic and environmental dimensions, and iii) diverse geographic contexts and scales, to capture emerging properties allowing for cross-cultural comparisons. We provide specific guidelines for formally developing a coherent set of sustainability indicators that are transferable across time and space, and can track sustainability. In an exploratory exercise, we also show that very distinct pastoralist systems have undergone similar transitions across time, approaching critical thresholds and then either collapsing or recovering. An integrated view of the interactions between the environmental, social and economic dimensions of these transitions allows for an improved understanding of potential tipping points, hence supporting more proactive and informed decision-making. We conclude that the need for a paradigm shift in pastoralism science and policy is pressing. Determining when, where and how is pastoralism not only sustainable, but also the most adaptive livelihood, has become a priority. This paper is based on Manzano et al. (2021).Peer reviewe
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