Weathering Processes on Sandstone Painting and Carving Surfaces at Prehistoric Rock Sites in Southern Spain

The sandstones which constitute the host rock for the prehistoric artwork in the Rock Groups of Tajo de las Figuras and Peñas de Cabrera (southern Spain) show a serious degree of alteration, due both to natural processes and those related to anthropogenic and animal activity. A detailed study was carried out on the petrological and compositional characteristics of the sandstones (fresh and altered rock) in both rock groups, and on the geological and climatological characteristics of the area in which they are located. The sandstones have very similar petrological and compositional characteristics in both areas. This likeness causes the nature of the natural weathering processes to be similar in the rock areas studied. These processes can be divided in terms of the predominant mechanisms of alteration into three inter-related categories: mechanical weathering, chemical weathering, and bio-induced alteration processes. However, the different climatic conditions of the areas in which the two rock areas are located directly influences the intensity of these processes. The precipitation and the range of temperature variation with heavy winter frosts in the area of El Tajo de las Figuras are significantly higher than in the area of Peñas de Cabrera; this translates into a higher rate of weathering at El Tajo de las Figuras. Regarding the anthropogenic action, two types of influence on the deterioration can be distinguished: a direct one, which consists of scouring and wetting of the walls in order to increase the chromatic contrast; and an indirect one, which is the extraction of blocks of sandstone in the upper part of rock shelters, which in turn encourages the development of the chemical weathering processes.This study forms part of the research agreement “Study and diagnosis of the archaeological groups and deposits of the Autonomous Community of Andalusia in their geomorphological, biological and climatic contexts” financed by the Culture Council, Junta of Andalusia (Spain)

Fast and accurate methodology for direct mercury determination in hair and nails

A solvent-free, easy, fast and waste-free methodology was developed for the determination of total mercury levels in hair and nails. Samples were taken from several volunteers and directly analysed, with levels of mercury in the range between 0.5 and 8 ng/mg. The influence of quantity of hair, as well as the addition of small amount of solvent and the necessity of previous treatment were studied. Also, a history of mercury exposure was provided by the distance of the hair from the scalp of each volunteer, the results of which were correlated with fish consumption. Furthermore, a short study of mercury in nails was carried out and correlated to the results from hair mercury levels. A small quantity of 5 mg of hair with an addition of 50 μL of water to the sample without previous treatment was adequate to get a representative result in less than 10 minutes. The accuracy of the proposed method was confirmed by analysing certified reference materials including Coal Fly Ash-NIST SRM 1633b, Fucus-IAEA 140 and three unpolished Rice Flour NIES-10. The observed results were found to be in good agreement with the certified values

Estimation of soil gas permeability for assessing radon risk using Rosetta pedotransfer function based on soil texture and water content

Radon is a natural source of radioactivity and it can be found in all soils and rocks in the Earth. The presence of radon gas in indoor environments implies a serious risk for human health, already listed as carcinogenic by the World Health Organization. The most relevant methods to infer the risk for radon exposure are based on soil radon concentration and gas permeability that describe the effective radon movement in the soil. However, they neglect crucial soil properties and water content in soil, which can affect greatly soil permeability to gases. Additionally, soil permeability measurement remains expensive, difficult and time-consuming. In this paper we show a new and simple methodology to infer radon risk based on Rosetta3 pedotransfer function as well as soil texture and water content. We also determine the influence of soil texture both on the gas permeability variation in dependence on water content and on the parameter n of the van Genuchten –Mualem model, which establishes the shape of the relative permeability curves. We show that radon risk exposure may change importantly for the same soil with different soil water contents. We finally apply and validate the proposed method using radon permeability data from the Canadian component of the North American Soil Geochemical Landscapes Project (NASGLP). Results highlight that the proposed methodology provides reliable estimations of the gas permeability and reveal that the presence of water content may cross the boundary between two radon risk categories, and consequently, may change the radon risk category to safer situations.This work was supported by the Spanish Government [grant number RTI2018-099052-B-I00] and the University of Alicante [grant number GRE17-12]

Calcitization of Mg±Ca carbonate and Ca sulphate deposits in a continental Tertiary basin (Calatayud Basin, NE Spain)

Diagenetic carbonates formed through early calcitization of evaporite (gypsum, anhydrite) and/or magnesium carbonate (dolomite, magnesite) deposits have been identified throughout the Tertiary Calatayud Basin (NE Spain). The diagenetic carbonates consist in all cases of low magnesian calcite and are related to main sedimentary discontinuities, which record episodes of significant subaerial exposure in the basin. Early calcite replacements predominate in sediments of the Intermediate Unit in central areas of the basin. Two types of diagenetic carbonates have been distinguished: (1) laminated diagenetic carbonates in which the original structure of sequences formed of laminated magnesite, dolomite and primary gypsum is preserved, though transformed in calcite; (2) brecciated diagenetic carbonates, which resulted from extensive dissolution of lenticular gypsum macrocrystals accompanied by dedolomitization processes of dolomite host rock. The replacement by calcite resulted from rapid transformation of evaporite deposits either at the contact of these deposits with overlying freshwaters or by percolating freshwater at very shallow burial depth. Stable isotope (carbon and oxygen) analyses of the diagenetic carbonates support influence of meteoric-derived carbonate-rich groundwater for their formation. The meteoric isotope signature is supported by its comparison with the stable isotope values determined from diagenetic calcites formed after magnesite in evaporite sequences during the Late Pleistocene and Holocene. The diagenetic carbonate bodies formed as a result of a progressive change from highly to moderately concentrated saline lake waters. This gradual evolution was related to a climatic shift from dry and hot to cooler and more humid conditions throughout the Miocene, a trend that has been also recognized in other large Tertiary basins of the Iberian Peninsula in this period

Palaeoenvironmental reconstruction of a middle Miocene alluvial fan to cyclic shallow lacustrine depositional system in the Calatayud Basin (NE Spain)

The middle Miocene sedimentary fill of the Calatayud Basin in north-eastern Spain consists of proximal to distal alluvial fan-floodplain and shallow lacustrine deposits. Four main facies groups characteristic of different sedimentary environments are recognized: (1) proximal and medial alluvial fan facies that comprise clast-supported gravel and subordinate sandstone and mudstone, the latter exhibiting incipient pedogenic features; (2) distal alluvial fan facies, formed mainly of massive mudstone, carbonate-rich palaeosols and local carbonate pond deposits; (3) lake margin facies, which show two distinct lithofacies associations depending on their distribution relative to the alluvial fan system, i.e. front (lithofacies A), comprising massive siliciclastic mudstone and tabular carbonates, or lateral (lithofacies B) showing laminated and/or massive siliciclastic mudstone alternating with tabular and/or laminated carbonate beds; and (4) mudflat–shallow lake facies showing a remarkable cyclical alternation of green-grey and/or red siliciclastic mudstone units and white dolomitic carbonate beds. The cyclic mudflat–shallow lake succession, as exposed in the Orera composite section (OCS), is dominantly composed of small-scale mudstone–carbonate/dolomite cycles. The mudstone intervals of the sedimentary cycles are interpreted as a result of sedimentation from suspension by distal sheet floods, the deposits evolving either under subaerial exposure or water-saturated conditions, depending on their location on the lacustrine mudflat and on climate. The dolomite intervals accumulated during lake-level highstands with Mg-rich waters becoming increasingly concentrated. Lowstand to highstand lake-level changes indicated by the mudstone/dolomite units of the small-scale cycles reflect a climate control (from dry to wet conditions) on the sedimentation in the area. The spatial distribution of the different lithofacies implies that deposition of the smallscale cycles took place in a low-gradient, shallow lake basin located in an interfan zone. The development of the basin was constrained by gradual alluvial fan aggradation. Additional support for the palaeoenvironmental interpretation is derived from the isotopic compositions of carbonates from the various lithofacies that show a wide range of δ18O and δ13C values varying from )-7.9 to 3.0‰ PDB and from -9.2 to -1.7‰ PDB respectively. More negative δ18O and δ13C values are from carbonate-rich palaeosols and lakemargin carbonates, which extended in front of the alluvial fan systems, whereas more positive values correspond to dolomite beds deposited in the shallow lacustrine environment. The results show a clear trend of δ18O enrichment in the carbonates from lake margin to the centre of the shallow lake basin, thereby also demonstrating that the lake evolved under hydrologically closed conditions

Microclimatic studies in Paranhos water galleries, Porto (Portugal)

Sanz Rubio, Enrique et al.-- 4 pages, 3 figures, 4 references.-- Proceedings of the International Congress on Science and Technology for the Conservation of Cultural Heritage, held 2-5 october, Santiago de Compostela, España.Paranhos constitutes one of the main water galleries excavated in the granite substratum of Porto City (Portugal) to gather the groundwater for public use during the past six centuries. The interest of this water gallery is double: a) Cultural Heritage and scientific value, b) Underground geoturism. A multidisciplinary research to study the microclimatology, geochemistry, mineralogy and geomicrobiology of the Paranhos catchwork galleries is currently in progress. The characterization of the main environmental parameters (air-rock temperature, relative humidity, CO2, 222Rn, etc.) in the internal atmosphere would allow the establishment of: a) Fluid-rock interactions and development of a physical-chemical model of air-water-rock, as a base to define their relations with unusual mineral formations and microbial communities b) Microclimatic parameters and determination of effective radioactive dose for visitors based on 222Rn studies, as potential use as underground geotourism site under safe conditions.This research was supported by the Spanish Project CGL2011-25690.Peer reviewe

Patrimonio geológico: valorización y utilización funcional

The geological heritage has usually undergone legislative or conceptual developments. A new strategy is here proposed, which intends to change the ordinary point of view towards a horizontal model, including a bigger participation of social and economic agents of a region. A change in information, education and participation processes apears necessary. Such change should be based on a deeper analysis of the geological reality related to the results of European program targets as well as on a more structured view of the places of geological interest

Espesura crítica y regeneración en un pinar natural de silvestre de elevada complejidad estructural (monte “Cabeza de Hierro”, Rascafría, Madrid)

El monte privado “Cabeza de Hierro” (Rascafría, Madrid), con 2.016,5 ha de superficie total y 1.886,4 ha de superficie arbolada, presenta una masa de pino silvestre de origen natural con abundante melojo, de elevado valor económico y ecológico, sobre la que se realizan aprovechamientos maderables desde hace al menos 150 años. La mayor parte del monte está incluido en la Zona Periférica de Protección del Parque Natural de la Cumbre, Circo y Lagunas de Peñalara. Ordenado desde 1957, se siguió primero el método de tramos permanentes, y después el de tramo móvil. Las cortas de regeneración aplicadas han sido de aclareo sucesivo. La gran variabilidad estacional, el intenso aprovechamiento pastoral y la competencia con melojo y matorral han generado una estructura de elevada complejidad, de modo que en general aparece un mosaico de bosquetes de tamaño variable, en cuyo interior la masa es regular o semirregular, generando una estructura irregular a escala de cantón. En este trabajo se estudia, mediante diversas técnicas de análisis multivariante y en especial mediante análisis discriminante, la relación entre la aparición de regeneración y diversos factores del medio y de la masa, con el objetivo principal de comprobar por debajo de qué espesura crítica es esperable la instalación de regeneración suficiente. La propuesta se realiza para diferentes situaciones presentes en el monte. Para ello se emplea la información recogida en el Estado Forestal de la Tercera Revisión del Proyecto de Ordenación (2007) para los cuarteles A y B, de 806,3 ha totales y 776,7 ha arboladas. Dicha información procede de un muestreo cuyas características se resumen a continuación: muestreo estratificado con afijación proporcional, parcelas circulares de radios concéntricos, distribución sistemática con lado de malla cuadrada de 160 m. Como resumen de los resultados se encuentra que: elevadas espesuras en pinar adulto no impiden la instalación del diseminado, aunque luego éste muere por falta de luz; la presencia abundante de otras especies (matorral, melojo o acebo) sí impide o dificulta la regeneración; como valor global aproximado, se propone un rango de valores de área basimétrica crítica total, suma de la de pinos mayores, melojos y acebos, de 16 a 30 m 2 /ha para permitir la regeneración suficiente de pino silvestre. El valor de espesura crítica se puede concretar para cada combinación de calidad de suelo, número de pies menores y fracción de cabida cubierta de especies acompañantes

Hemisynthesis and Absolute Configuration of novel 6-pentyl-2H-pyran- 2-one derivatives from Trichoderma spp

A comparative study of the secondary metabolism of two Trichoderma spp. with that of the Thctf1 transcription factor gene null mutant of Trichoderma harzianum 34 was carried out in order to deepen our knowledge of the biosynthetic pathway and mode of action of 6-pentyl-2H-pyran-2-one (1) and its derivatives as biocontrol agents. New isolated metabolites have shed light on the detoxification mechanism of 6-pentyl-pyranone by Trichoderma spp. All new compounds were synthesized and their stereoisomer characterized. The absolute configuration of 6-[(10R,20S)-dihydroxypentyl]-2H-pyran-2-one and 6-((10S,20R)-20-propyloxiran-1-yl)-2H-pyran-2-one was determined by NMR analysis of the corresponding Mosher’s esters

TMT: una herramienta para guiar a los usuarios en la búsqueda de información sobre textos clínicos

La gran cantidad de información médica disponible a través de internet, tanto en formato estructurado como en formato texto, hace que los distintos tipos de usuario se encuentren con diferentes problemas a la hora de efectuar una búsqueda efectiva. Por un lado, los estudiantes de medicina, el personal sanitario y los investigadores en el área de la biomedicina disponen de una gran variedad de fuentes y herramientas de características dispares, que precisan de un periodo de aprendizaje a veces insalvable. Por otro lado, los pacientes, sus familiares y personas que no pertenecen a la profesión médica, se encuentran con el problema añadido que supone no estar suficientemente familiarizados con la terminología médica. En este artículo presentamos una herramienta que permite extraer conceptos médicos relevantes presentes en un texto clínico, haciendo uso de técnicas para el reconocimiento de entidades nombradas, aplicadas sobre listas de conceptos, y técnicas de anotación a partir de ontologías. Para proponer los conceptos se hace uso de un recurso no formal de conocimiento, como es Freebase, y de recursos formales como son Medlineplus y Pubmed. Nosotros argumentamos que la combinación de estos recursos, con información menos formal y en lenguaje más divulgativo (como es Freebase), con información formal y en lenguaje más divulgativo (como es Medlineplus) o con información formal y en lenguaje más especializado (como son las publicaciones científicas de Pubmed), optimiza el proceso de localización de información médica sobre un caso clínico complejo a usuarios con diferentes perfiles y necesidades, tales como son los pacientes, los médicos o los investigadores. Nuestro objetivo último es la construcción de una plataforma que permita albergar diferentes técnicas para facilitar la práctica de la medicina traslacional.The large amount of medical information available through the Internet, in both structure and text formats, makes that different types of users will encounter different problems when they have to carry out an effective search. On the one hand, medical students, health staff and researchers in the field of biomedicine have a variety of sources and tools of different characteristics which require a learning period sometimes insurmountable. On the other hand, patients, family members and people outside of the medical profession, face the added problem of not being sufficiently familiarized with medical terminology. In this paper we present a tool that can extract relevant medical concepts present in a clinical text, using techniques for named entity recognition, applied on lists of concepts, and annotation techniques from ontologies. To propose these concepts, our tool makes use of a non formal knowledge source, such as Freebase, and formal resources such as MedlinePlus and PubMed. We argue that the combination of these resources, with information less formal and more plain language (like Freebase), with formal information and more plain language (like Medlineplus) or with formal information and more technical language (such as the Pubmed scientific literature), optimize the process of discover medical information on a complex clinical case to users with different profiles and needs, such as are patients, doctors or researchers. Our ultimate goal is to build a platform to accommodate different techniques facilitating the practice of translational medicine