Pluridisciplinary analysis and multi-archive reconstruction of paleofloods: societal demand, challenges and progress

Floods are one of the gravest natural hazards for societies, worsened by population growth, unchecked development, and climate change. From a Global Change perspective, past extreme events merit particular interest because they can be linked to wider climate and environmental changes, introduce perturbations. During the last decade, knowledge of long-term flood frequency and magnitude has been improved by extracting data from different types of archive. But, despite advances in dating methods, proxies and statistical techniques and efforts to identify atmospheric drivers, some fundamental questions remain unresolved. The Special Issue entitled "Pluridisciplinary analysis and multi-archive reconstruction of paleofloods" in the journal Global and Planetary Change addresses these uncertainties and complexities by assembling a selection of studies, which were first presented at the Past Climate Changes (PAGES) Open Scientific Meeting held at Zaragoza in 2017. In this introductory paper, the guest editors outline the 17 research contributions and meta-data from the 17 paleoflood studies were systematically analyzed in terms of i) geographical distribution; ii) methodologies applied; iii) types of archives; iii) numbers of flood series compiled and iv) spatial and temporal resolution of paleoflood data. The data indicate that paleoflood studies focused on fluvial depositional environments show a higher rate of integration with other types of paleoflood archive (mean of 4.5 types of archive) than studies focused on documentary sources (mean of 3.5) and lake sediments (mean of 2.4). We suggest that this strategy of archive integration has been adapted to effectively compensate for the higher uncertainties of fluvial deposition in floodplains

Complicaciones en la anestesia general del perro : revisión de 265 casos

Un total de 265 perros fueron anestesiados por diferentes motivos diagnósticos y terapéuticos en los Servicios Clínicos de la Facultad de Veterinaria de Córdoba,siguiendo diversos protocolos anestésicos

Reversión de sedantes agonistas alfa-2-adrenérgicos en el perro

En el presente Artículo de Revisión se aporta una información amplia sobre los productos de LISO más frecuente en la reversión de los efectos sedantes de los agonistas alfa-2-adrenérgicos empleados en el perro: xilacina, medetomidina y romifidina. Se refieren los detalles farmacológicos, dosificación, efectos y aplicaciones de los siguientes productos: yohimbina, 4-aminopiridina, doxapram y atipamezol

The desiccation of LasTablas de Daimiel (1750-1987): agricultural changes and environmental impact based on interpretation of the sedimentary record

El Parque Nacional de lasTablas de Daimiel es un humedal de importancia internacional sometido a una fuerte presión agraria desde el siglo XVIII.El impacto de dicha presión ha sido analizado a partir del estudio de los sedimentos acumulados en el interior del humedal. Se han encontrado varias anomalías sedimentarias que separan al humedal de su comportamiento natural.Se han establecido cuatro épocas de alteración importantes:el primer proyecto de desecación en la dé cada de 1750;el aumento de la superficie cultivada en el entorno durante la segunda mitad del siglo XIX;el intento de desecación promovido durante la Segunda República; y la degradación definitiva en la segunda mitad del siglo XX.Estas perturbaciones han sido corroboradas por fuentes historiográficas,concluyendo que los sucesivos proyectos de desecación desde el siglo XVIII, los cambios en la agricultura española contemporánea, la deforestación del entorno y la expansión del regadío han transformado el humedal.Located in a semi-arid zone of the central Iberian Peninsula, the Tablas de Daimiel National Park is a wetland of international significance that has experienced intense agricultural pressure since the eighteenth century.The impact of this is recorded in the sediments within the wetland,which have been studied by means of surveys.Several sediment anomalies have been found that were caused by an increase in agricultural activities, distinguishing this wetland from natural sedimentary behaviour. Four phases of significant disturbance have been established:the first drainage project in the 1750s,an increase in cultivated area in the surrounding land during the second half of the nineteenth century, a drainage attempt during the Spanish Second Republic and a final degradation in the second half of the twentieth century.Dated with some uncertainty due to the laboratory methods used,these disturbances have been corroborated by historical sources.In conclusion, one can establish that deforestation in the surrounding land,changes in land use,continual ploughing and drainage projects are all crucial in explaining the impoverishment of this wetland.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEMinisterio de Economía y Competitividad (MINECO)pu

The Sloan Digital Sky Survey Reverberation Mapping Project : how broad emission line widths change when luminosity changes

Funding: National Science Foundation of China (11721303, 11890693, 11991052) and the National Key R&D Program of China (2016YFA0400702, 2016YFA0400703). YS acknowledges support from an Alfred P. Sloan Research Fellowship and NSF grant AST-1715579. CJG, WNB, JRT, and DPS acknowledge support from NSF grants AST-1517113 and AST-1516784. KH acknowledges support from STFC grant ST/R000824/1. PBH acknowledges support from NSERC grant 2017-05983. YH acknowledges support from NASA grant HST-GO-15650.Quasar broad emission lines are largely powered by photoionization from the accretion continuum. Increased central luminosity will enhance line emissivity in more distant clouds, leading to increased average distance of the broad-line-emitting clouds and decreased averaged line width, known as the broad-line region (BLR) "breathing". However, different lines breathe differently, and some high-ionization lines, such as C IV, can even show "anti-breathing" where the line broadens when luminosity increases. Using multi-year photometric and spectroscopic monitoring data from the Sloan Digital Sky Survey Reverberation Mapping project, we quantify the breathing effect (Δlog W=αΔlog L) of broad Hα, Hβ, Mg II, C IV,and C III] for statistical quasar samples over z≈0.1−2.5. We found that Hβ displays the most consistent normal breathing expected from the virial relation (α∼−0.25), Mg II and Hα on average show no breathing (α∼0), and C IV (and similarly C III] and Si IV mostly shows anti-breathing (α>0). The anti-breathing of C IV can be well understood by the presence of a non-varying core component in addition to a reverberating broad-base component, consistent with earlier findings. The deviation from canonical breathing introduces extra scatter (aluminosity-dependent bias) in single-epoch virial BH mass estimates due to intrinsic quasar variability, which underlies the long argued caveats of C IV single-epoch masses. Using the line dispersion instead of FWHM leads to less, albeit still substantial, deviations from canonical breathing in most cases. Our results strengthen the need for reverberation mapping to provide reliable quasar BH masses, and quantify the level of variability-induced bias in single-epoch BH masses based on various lines.PostprintPeer reviewe

Natural and anthropogenic processes in La Janda basin (SW Iberia) from the Late Pleistocene to the Mid-Late Holocene

A multiproxy study (pollen, non-pollen palynomorphs, sedimentology, and geochemistry) was carried out in two cores drilled in La Janda basin (SW Iberia) to trace the environmental evolution and human impact on the landscape. An incised fluvial valley existed in the basin during the Late Pleistocene, followed by a transitional environment characterized by the development of saltmarsh vegetation affected by the increased marine influence ca. 10/8.7 ka cal BP. During this period comprising the Upper Palaeolithic and Mesolithic (>∼7.8 ka cal BP), the impact of hunter-gatherer groups on the landscape was rather low according to palynological and geochemical records. A restricted estuary connected to the sea was identified in La Janda between ca. 10/8.7-3.5/3.3 ka cal BP, coinciding with a predominance of saltmarsh vegetation developing on saline shore soils and the punctual presence of foraminifera and dynoflagellate cysts. The anthropogenic pressure was progressively increasing during the Neolithic, especially from ca. 7 ka cal BP, with markers suggesting herding/livestock activities prior to the punctual presence of cereals, which is only confirmed by the archaeological record ca. 6 ka cal BP. Human pressure become more noticeable throughout the Chalcolithic and Bronze Age (∼5-3 ka cal BP), period during which a new transitional phase is recorded in La Janda (ca. 3.5/3.3-1.3 ka cal BP), culminating in the terrestrialization of the area. The predominance of freshwater taxa and decrease of saltmarsh vegetation is observed during this period, and the transformation of the landscape for agricultural activities over the last centuries is reflected in the local presence of cereals and markers of erosive processes.This research was funded by the Deutsche Forschungsgemeinschaft-DFG (project no.57444011 – SFB 806); a “Severo Ochoa” extraordinary grant for excellence IGME, CSIC (AECEX2021); the Consejería de Cultura of the Junta de Andalucía (projects DGBC/IDBC3741 and 4766); the FEDER/MINECO-AGEINVES (HAR2017-8734P); and the Operational Programme and Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia (FEDERUCA18-106917)Peer reviewe

An irradiated brown-dwarf companion to an accreting white dwarf

Interacting compact binary systems provide a natural laboratory in which to study irradiated substellar objects. As the mass-losing secondary (donor) in these systems makes a transition from the stellar to the substellar regime, it is also irradiated by the primary (compact accretor)1, 2. The internal and external energy fluxes are both expected to be comparable in these objects, providing access to an unexplored irradiation regime. The atmospheric properties of donors are largely unknown3, but could be modified by the irradiation. To constrain models of donor atmospheres, it is necessary to obtain accurate observational estimates of their physical properties (masses, radii, temperatures and albedos). Here we report the spectroscopic detection and characterization of an irradiated substellar donor in an accreting white-dwarf binary system. Our near-infrared observations allow us to determine a model-independent mass estimate for the donor of 0.055 ± 0.008 solar masses and an average spectral type of L1 ± 1, supporting both theoretical predictions and model-dependent observational constraints that suggest that the donor is a brown dwarf. Our time-resolved data also allow us to estimate the average irradiation-induced temperature difference between the dayside and nightside of the substellar donor (57 kelvin) and the maximum difference between the hottest and coolest parts of its surface (200 kelvin). The observations are well described by a simple geometric reprocessing model with a bolometric (Bond) albedo of less than 0.54 at the 2σ confidence level, consistent with high reprocessing efficiency, but poor lateral heat redistribution in the atmosphere of the brown-dwarf donor4, 5. These results add to our knowledge of binary evolution, in that the donor has survived the transition from the stellar to the substellar regime, and of substellar atmospheres, in that we have been able to test a regime in which the irradiation and the internal energy of a brown dwarf are comparable