2,219 research outputs found

    Bayesian estimates of marine radiocarbon reservoir effect in northern Iberia during the Early and Middle Holocene

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    Reconstructing the past variability of marine radiocarbon reservoir effects (MRE) is crucial for generating reliable chronologies for marine species and their consumers. We investigated the temporal MRE variability at the Early-to Mid-Holocene site of El Mazo (Asturias, northern Spain) by using a combination of new and previously published radiocarbon measurements on marine and terrestrial samples. The El Mazo site is characterized by overall well-defined archaeological layers of unknown occupation length with the predominant presence of two mollusc species (Patella vulgata Linnaeus, 1758 and topshell Phorcus lineatus [da Costa, 1778]) which were analysed for radiocarbon measurements. We employed the recently released IntCal20 calibration curve for the northern hemisphere and Bayesian modelling to reconstruct the site?s chronology and temporal variability in MREs according to mollusc species. Obtained radiocarbon modelling results, although the estimate precision is not high, reveal a temporal variability in MREs that can be interpreted in view of known past climatic and environmental events such as the 8.2 ka event. The results also revealed differences in MREs according to mollusc species, which need to be taken into account in future chronological modelling. Overall, our results provide reference MRE values for the study of chronologies in northern Iberia during the Early-to Mid-Holocene. In this respect, a non-conservative ?R reference for local marine samples dating earlier than c. 8.1 ka cal BP is - 238 ± 28 14C years.This research was performed as part of the projects HAR 2016- 75605-R and HAR 2017-86262-P, funded by the Spanish Ministry of Economy and Competitiveness, MINECO. During the development of this research AGE was funded by the Basque Country Postdoctoral Programme through a postdoctoral grant (POS_2020_2_0032) and University of La Rioja (no code available). This study has also been supported by the Prehistoric Research Consolidated Group of the Basque Country University (IT-1223-19), funded by the Basque Country Government. PR and RF are funded by the Max Planck Society. We thank the Fishing Activity Service of the Cantabrian Government for the authorization to collect modern specimens. We also thank the Max Plank Society, University of La Rioja, Basque Country University (UPV/EHU), University of Cantabria (UC) and Instituto Internacional de Investigaciones Prehist´oricas de Cantabria (IIIPC) for providing support

    Numerical simulation of the deadliest flood event of Portugal: Unravelling the causes of the disaster

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    The flood event of November 25 and 26, 1967 corresponds to the deadliest storm affecting Portugal in recent centuries being responsible for >500 fatalities. The main trigger was the heavy rain that fell in just a few hours, provoking a rapid increase in river flows, although other concurrent circumstances had to occur to reach the dramatic water levels estimated in some affected places. However, even today, several important uncertainties related to water levels achieved and timing of floods remain. Here we aim to clarify some of the pending issues by applying suitable high performance numerical tools to elucidate the main conditioning factors that played a key role in the intensification of this dramatic flood. In particular, the analysis has been focused on Quintas village, the location most affected, where >100 fatalities were recorded, close to 2/3 of its total population at the time. The main conclusion provided by the numerical simulations was that a plugging of water flow downstream of Quintas village, favoured by a poor terrain maintenance coupled with the bottleneck created by topographic features, caused the critical over-elevation of water levels. Simulations also corroborate the rapid increase in water levels in Quintas village, with an estimated rise of >2 m in just two hours, as well as the occurrence of the flood during the night, preventing many people to be aware of the extreme danger they were facing and safeguarding themselves.Universidade de Vigo/CISU

    The Rivillas flood of 5–6 November 1997 (Badajoz, Spain) revisited: an approach based on Iber+ modelling

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    Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGThe flash flood registered in November 1997 in the city of Badajoz (Spain) in the basin of Rivillas river is analysed by means of the numerical code Iber+. This event constitutes one of the most destructive flash-floods registered in an urban area in the Iberian Peninsula. Starting from precipitation data obtained from rain stations, the runoff of the entire river basin was simulated to obtain the discharge of the Rivillas river in Badajoz. The flood maps obtained with Iber+ reproduce accurately the field data registered during the actual event. Likewise, the numerical time evolution of the flood and water depths are in accordance with testimonies of the witnesses. Once the capability of Iber+ to reproduce the event was assessed, several scenarios were considered in order to analyse the main causes of the event. In particular, simulations show that the catastrophic magnitude of the flood was mainly due to the blockage of bridges. Different hypothetical scenarios were simulated to analyze the role of rain intensity and bridge maintenance, concluding that similar floods can occur under much lower rainfall but with poor bridge maintenance.Xunta de Galicia | Ref. ED431C 2021/44Xunta de Galicia | Ref. ED481B-2021-10

    Limited risk of Zika virus transmission by five Aedes albopictus populations from Spain

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    Background: Aedes albopictus, the Asian tiger mosquito, is an exotic invasive species in Europe. It has substantial public health relevance due to its potential role in transmitting several human pathogens. Out of the European coun‑ tries, Spain has one of the highest risk levels of autochthonous arbovirus transmission due to both the high density of Ae. albopictus and the extensive tourist infux from vector-endemic areas. This study aims to investigate the suscep‑ tibility of fve Ae. albopictus populations from mainland Spain and the Balearic Islands to a Brazilian Zika virus (ZIKV) strain. Methods: The F1 generation of each Ae. albopictus population was orally challenged with a ZIKV-infected blood meal (1.8×106 PFU/ml). At 7 and 14 days post-infection (dpi), mosquito bodies (thorax and abdomen) and heads were individually analysed through RT-qPCR to determine the infection rate (IR) and dissemination rate (DR), respectively. The saliva of infected mosquitoes was inoculated in Vero cells and the transmission rate was assessed by plaque assay or RT-qPCR on ~33 individuals per population. Results: The IR and DR ranged between 12–88%, and 0–60%, respectively, suggesting that ZIKV is capable of cross‑ ing the midgut barrier. Remarkably, no infectious viral particle was found in saliva samples, indicating a low ability of ZIKV to overcome the salivary gland barrier. A subsequent assay revealed that a second non-infective blood meal 48 h after ZIKV exposure did not infuence Ae. albopictus vector competence. Conclusions: The oral experimental ZIKV infections performed here indicate that Ae. albopictus from Spain become infected and disseminate the virus through the body but has a limited ability to transmit the Brazilian ZIKV strain through biting. Therefore, the results suggest a limited risk of autochthonous ZIKV transmission in Spain by Ae. albopictusinfo:eu-repo/semantics/publishedVersio

    Effects of different arbuscular mycorrhizal fungal backgrounds and soils on olive plants growth and water relation properties under well-watered and drought conditions

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    17 páginas.-- 6 figuras.-- 5 tablas.-- 89 referencias.-- Additional Supporting Information may be found in the online version of this article at the publisher’s web-siteThe adaptation capacity of olive trees to different environments is well recognized. However, the presence of microorganisms in the soil is also a key factor in the response of these trees to drought. The objective of the present study was to elucidate the effects of different arbuscular mycorrhizal (AM) fungi coming from diverse soils on olive plant growth and water relations. Olive plants were inoculated with native AM fungal populations from two contrasting environments, that is, semi-arid – Freila (FL) and humid – Grazalema (GZ) regions, and subjected to drought stress. Results showed that plants grew better on GZ soil inoculated with GZ fungi, indicating a preference of AM fungi for their corresponding soil. Furthermore, under these conditions, the highest AM fungal diversity was found. However, the highest root hydraulic conductivity (Lp) value was achieved by plants inoculated with GZ fungi and growing in FL soil under drought conditions. So, this AM inoculum also functioned in soils from different origins. Nine novel aquaporin genes were also cloned from olive roots. Diverse correlation and association values were found among different aquaporin expressions and abundances and Lp, indicating how the interaction of different aquaporins may render diverse Lp values.The study was supported by the Ministry of Economy and Competitiveness of Spain (Juan de la Cierva Program) and Junta de Andalucía (P10-CVI-5920 project) for research funding.Peer reviewedPeer Reviewe

    Recensiones [Revista de Historia Económica Año XVIII Otoño-Invierno 2000 n. 3 pp. 687-734]

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    Editada en la Fundación Empresa PúblicaColl, S., y Guijarro, M.: Estadística aplicada a las Ciencias Sociales (Por Daniel Peña).-- Tedde de Lorca, P.: El Banco de San Femando (1829-1856) (Por Carlos Marichal).-- Comín Comín, F., y Martín Aceña, P.: Tabacalera y el estanco de tabaco en España (1636-1998) (Por Lina Gálvez Muñoz).-- Millán García-Várela, J.: El poder de la tierra. La sociedad agraria del bajo Segura en la época del liberalismo (Por Ricardo Robledo).-- Matés Barco, J. M.: La conquista del agua. Historia económica del abastecimiento urbano (Por Beatriz Mera González).-- Ortiz Batalla, J.: Los Bancos Centrales en América Latina (Por Raúl García Heras).-- Guirao, F.: Spain and the Reconstruction of Western Europe, 1945-57: Challenge and Response (Por Jordi Catalán).-- Aghion, P., y Howitt, P.: Endogenous Growth Theory (Por Joan R. Rosés).-- Dye, A. D.: Cuban Sugar in the Age of Mass Production. Technology and the Economics of Sugar Central, 1899-1929 (Por Antonio Santamaría García).-- Gourvish, T. R., y Tiratsoo, N. (eds.): Missionaries and managers: American influences on European management education, 1945-60 (Por Nuria Puig).-- Coastworth, J., y Taylor, A. (eds.): Latin America and the World Economy since 1800 (Por Gustavo A. del Ángel-Mobarak)Publicad

    Biometric system verification close to "real world" conditions

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    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-04391-8_31Proceedings of Joint COST 2101 and 2102 International Conference, BioID_MultiComm 2009, Madrid, Spain.In this paper we present an autonomous biometric device developed in the framework of a national project. This system is able to capture speech, hand-geometry, online signature and face, and can open a door when the user is positively verified. Nevertheless the main purpose is to acquire a database without supervision (normal databases are collected in the presence of a supervisor that tells you what to do in front of the device, which is an unrealistic situation). This system will permit us to explain the main differences between what we call "real conditions" as opposed to "laboratory conditions".This work has been supported by FEDER and MEC, TEC2006-13141-C03/TCM, and COST-2102

    Potential Operating Models, Harvest Control Rules and Performance Statistics for the NAFO 3M Cod MSE.

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    This document presents a proposal of possible Operating Models (OMs), Harvest Control Rules (HCR) and Performance Statistics (PS) to carry out the Management Strategies Evaluation (MSE) for the 3M cod of NAFO. This proposal will have to be reviewed by the NAFO SC to decide the first set of OMs to test with the possible HCRs in the 3M Cod MSE

    Evolution of naturally occurring 5'non-coding region variants of Hepatitis C virus in human populations of the South American region

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    <p>Abstract</p> <p>Background</p> <p>Hepatitis C virus (HCV) has been the subject of intense research and clinical investigation as its major role in human disease has emerged. Previous and recent studies have suggested a diversification of type 1 HCV in the South American region. The degree of genetic variation among HCV strains circulating in Bolivia and Colombia is currently unknown. In order to get insight into these matters, we performed a phylogenetic analysis of HCV 5' non-coding region (5'NCR) sequences from strains isolated in Bolivia, Colombia and Uruguay, as well as available comparable sequences of HCV strains isolated in South America.</p> <p>Methods</p> <p>Phylogenetic tree analysis was performed using the neighbor-joining method under a matrix of genetic distances established under the Kimura-two parameter model. Signature pattern analysis, which identifies particular sites in nucleic acid alignments of variable sequences that are distinctly representative relative to a background set, was performed using the method of Korber & Myers, as implemented in the VESPA program. Prediction of RNA secondary structures was done by the method of Zuker & Turner, as implemented in the <it>mfold </it>program.</p> <p>Results</p> <p>Phylogenetic tree analysis of HCV strains isolated in the South American region revealed the presence of a distinct genetic lineage inside genotype 1. Signature pattern analysis revealed that the presence of this lineage is consistent with the presence of a sequence signature in the 5'NCR of HCV strains isolated in South America. Comparisons of these results with the ones found for Europe or North America revealed that this sequence signature is characteristic of the South American region.</p> <p>Conclusion</p> <p>Phylogentic analysis revealed the presence of a sequence signature in the 5'NCR of type 1 HCV strains isolated in South America. This signature is frequent enough in type 1 HCV populations circulating South America to be detected in a phylogenetic tree analysis as a distinct type 1 sub-population. The coexistence of distinct type 1 HCV subpopulations is consistent with quasispecies dynamics, and suggests that multiple coexisting subpopulations may allow the virus to adapt to its human host populations.</p

    Supersonic Kinks in Coulomb lattices

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    There exist in nature examples of lattices of elements for which the interaction is repulsive, the elements are kept in place because different reasons, as border conditions, geometry (e.g., circular) and, certainly, the interaction with other elements in the system, which provides an external potential. A primer example are layered silicates as mica muscovite, where the potassium ions form a two dimensional lattice between silicate layers. We propose an extremely simplified model of this layer in order to isolate the properties of a repulsive lattice and study them. We find that they are extremely well suited for the propagation of supersonic kinks and multikinks. Theoretically, they may have as much energy and travel as fast as desired. This striking results suggest that the properties of repulsive lattices may be related with some yet not fully explained direct and indirect observations of lattice excitations in muscovite
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