Ecological impact of recreational bathing at Las Presillas (Lozoya River, Sierra de Guadarrama National Park, central Spain)

The ecological impacts of recreational uses on the rivers of Sierra de Guadarrama National Park (SGNP) have been scarcely studied. To assess the impacts of these uses at Las Presillas (an area with small dam along a section of the Lozoya River), and in the Lozoya River (upstream and downstream of the dams), the dynamics of the organic seston (FPOM), physicochemical vari-ables (electric conductivity, dissolved oxygen, Temperature, and pH) and biological variables (fecal coliforms, fecal streptococci, and aquatic macroinvertebrates) during the recreational (July to September) and nonrecreational (October) periods were assessed. The variations observed in the physicochemical parameters were associated with autumnal influence. However, at Las Presillas, different values were found than at the rest of the surveyed sites, characterized by an increase in the concentration of FPOM and, human fecal contamination (although they did not reach dangerous levels) and the response of the macroinvertebrate communities, which resulted in a clear decrease in the IBMWP index and other quality metrics, during the recreational period. These findings suggest that the combined effects of the dams and recreational activities at Las Presillas generate functional dynamics in that alter the habitat in summer. The identification and study of these impacts through the application of innovative indices and quality classes that integrate and contextualize Las Presillas in the SGNP monitoring network, have been identified as key management and conservation tool

Seeking for the best conditions for fish fossil preservation in Las Hoyas Konservat-Lagerstätte using microbial mats

Actuotaphonomic experiments demonstrate how microbial mats prevent or delay destructive processes. The rate at which carcasses are covered is a key to their preservation. Because of the growth rate of microbial mats depends on environmental conditions, a set of experiments have been carried out emulating the Barremian environmental conditions, analysed for temperatures at 14°C and 26°C (cooler and warmer seasons respectively) and atmospheric pCO2 (1000 ppm). For this purpose, the microbial mats were grown in mesocosms within an environmental chamber. Variations in primary production were quantified by measuring changes in dissolved O2 concentration in the water. Zebrafish carcasses were laid on the mats, and their coverage rates were calculated from the daily surface area covered by the mat. The results showed that the fish was covered twice as fast at 26°C, in coincidence with the highest values for the gross primary production and community respiration of the microbial mats. Therefore, for these Barremian conditions, the early stages of carcasses preservation would take place most effectively during the warmer seasons as decomposing activity would release nutrients that would enhance, together with temperature, the growth of matsThis study was funded by the Spanish Ministry of Science, Innovation and Universities [project PID2019-105546GB-I00

Temporal variation of phytoplankton in two neighbouring Mediterranean shallow lakes in Doñana National Park (Spain)

This study was aimed at describing the phytoplankton dynamics and structure of two eutrophic to hypereutrophic Mediterranean shallow lakes (Santa Olalla and Dulce). The two systems are close together and can function as one water body at times of heavy rainfall, but once separated, they evolve differently. The Shannon diversity index was low for both shallow lakes (average values of 1.11 in Santa Olalla and 1.79 in Dulce). The average phytoplankton Chl a concentrations and primary production rates were very high, although slightly higher in Santa Olalla (365.2 mg m-3 and 1.29 g C m-3 h-1, respectively) than in Dulce (230 mg m-3 and 0.88 g C m-3 h-1). Phytoplankton variation in the lakes was related to shifts in the physical and chemical features of lake water as well as hydrological conditions, a finding that is corroborated by the canonical correspondence analysis results, which showed a different pattern of evolution in each system. Eight functional groups were found in Santa Olalla (D, H1, J, K, M, S1, W2 and Y), although the D, W2 and Y groups were only predominant during the first four months of the study. For the rest of the period, the system was particularly dominated by the H1, K and S1 groups. Dulce exhibited a more complex distribution of phytoplankton functional groups over time. Ten functional groups were observed in this system (D, H1, J, K, M, P, S1, S2, W2 and Y). Some characteristics of these systems, such as rapid water volume fluctuations, low light penetration and low concentration of inorganic nutrients, are stressful conditions for phytoplankton, which may account for the low phytoplankton diversity and the equilibrium phases recorded for many months in both wetlands.El presente estudio tiene como objetivo describir la dinámica y estructura del fitoplancton en dos lagunas eutróficas a hipereutróficasMediterráneas (Santa Olalla y Dulce, España). Ambos sistemas están muy próximos y se unen superficialmente en periodos de fuertes lluvias, sin embargo, cuando el nivel desciende, evolucionan de forma separada. El índice de diversidad de Shannon fue bajo para ambos sistemas (valores promedio de 1.11 en Santa Olalla y 1.79 en Dulce). La concentración media de Chl a y las tasas de producción primaria del fitoplancton fueron muy altas, aunque ligeramente superior en Santa Olalla (365.2 mg m-3 y 1.29 g C m-3 h-1, respectivamente) con respecto a Dulce (230 mg m-3 y 0.88 g C m-3 h-1). Las variaciones del fitoplancton están relacionadas con cambios en las características físicas y químicas del agua, así como con las condiciones hidrológicas, lo que es corroborado por el Análisis de Correspondencia Canónica (CCA), que muestra un patrón de evolución diferente en ambos sistemas. En Santa Olalla fueron observados ocho grupos funcionales (D, H1, J, K, M, S1, W2 y Y), si bien los grupos D, W2 y Y sólo predominaron en los primeros cuatro meses de estudio. El resto del tiempo, el sistema estuvo dominado sobre todo por los grupos H1, K y S1. Dulce mostró una distribución más compleja de grupos funcionales a lo largo del tiempo, observándose diez grupos (D, H1, J, K, M, P, S1, S2, W2 y Y). Algunas de las características de ambos sistemas, como la rápida fluctuación en el volumen de agua, la baja penetración de la luz o la escasa concentración de nutrientes inorgánicos, son condiciones de estrés para el fitoplancton, lo que puede explicar su baja diversidad y las fases de equilibrio registradas durante muchos meses en ambos humedales

Preservation in microbial mats: mineralization by a talc-like phase of a fish embedded in a microbial sarcophagus

Frontiers in Earth Science 3 (2015): 51 This Document is Protected by copyright and was first published by Frontiers. All rights reserved. it is reproduced with permissionMicrobial mats have been repeatedly suggested to promote early fossilization of macroorganisms. Yet, experimental simulations of this process remain scarce. Here, we report results of 5 year-long experiments performed onfish carcasses to document the influence of microbial mats on mineral precipitation during early fossilization. Carcasses were initially placed on top of microbial mats. After 2 weeks, fish became coated by the mats forming a compact sarcophagus, which modified the microenvironment close to the corpses. Our results showed that these conditions favored the precipitation of a poorly crystalline silicate phase rich in magnesium. This talc-like mineral phase has been detected in three different locations within the carcasses placed in microbial mats for more than 4 years: (1) within inner tissues, colonized by several bacillary cells; (2) at the surface of bones of the upper face of the corpse buried in the mat; and (3) at the surface of several bones such as the dorsal fin which appeared to be gradually replaced by the Mg-silicate phase. This mineral phase has been previously shown to promote bacteria fossilization. Here we provide first experimental evidence that such Mg-rich phase can also be involved in exceptional preservation of animalsThis work, which is part of the research projects CGL2013-42643P and the research grant supporting MI were funded by the Spanish Ministry of Economy and Competitiveness. The SEM facility at IMPMC was supported by Region Ile de France grant SESAME 2006 I-07-593/R, INSU-CNRS, INP-CNRS, and University Pierre et Marie Curie, Paris. SEM analyses performed for this study were supported by a grant from the Foundation Simone et Cino Del Duca (PI: KB). We are also especially grateful to Olivier Beyssac for the help provided for RAMAN analysi

Metagenome-based diversity analyses suggest a significant contribution of non-cyanobacterial lineages to carbonate precipitation in modern microbialites

Frontiers in Microbiology 6 (2015): 797 This Document is Protected by copyright and was first published by Frontiers. All rights reserved. It is reproduced with permissionCyanobacteria are thought to play a key role in carbonate formation due to their metabolic activity, but other organisms carrying out oxygenic photosynthesis (photosynthetic eukaryotes) or other metabolisms (e.g., anoxygenic photosynthesis, sulfate reduction), may also contribute to carbonate formation. To obtain more quantitative information than that provided by more classical PCR-dependent methods, we studied the microbial diversity of microbialites from the Alchichica crater lake (Mexico) by mining for 16S/18S rRNA genes in metagenomes obtained by direct sequencing of environmental DNA. We studied samples collected at the Western (AL-W) and Northern (AL-N) shores of the lake and, at the latter site, along a depth gradient (1, 5, 10, and 15 m depth). The associated microbial communities were mainly composed of bacteria, most of which seemed heterotrophic, whereas archaea were negligible. Eukaryotes composed a relatively minor fraction dominated by photosynthetic lineages, diatoms in AL-W, influenced by Si-rich seepage waters, and green algae in AL-N samples. Members of the Gammaproteobacteria and Alphaproteobacteria classes of Proteobacteria, Cyanobacteria, and Bacteroidetes were the most abundant bacterial taxa, followed by Planctomycetes, Deltaproteobacteria (Proteobacteria), Verrucomicrobia, Actinobacteria, Firmicutes, and Chloroflexi. Community composition varied among sites and with depth. Although cyanobacteria were the most important bacterial group contributing to the carbonate precipitation potential, photosynthetic eukaryotes, anoxygenic photosynthesizers and sulfate reducers were also very abundant. Cyanobacteria affiliated to Pleurocapsales largely increased with depth. Scanning electron microscopy (SEM) observations showed considerable areas of aragonite-encrusted Pleurocapsa-like cyanobacteria at microscale. Multivariate statistical analyses showed a strong positive correlation of Pleurocapsales and Chroococcales with aragonite formation at macroscale, and suggest a potential causal link. Despite the previous identification of intracellularly calcifying cyanobacteria in Alchichica microbialites, most carbonate precipitation seems extracellular in this systemWe are grateful to Eleonor Cortés for help and good company during the field trip and to Eberto Novelo for helpful discussions at the UNAM lab. This research was funded by the European Research Council Grants ProtistWorld (PI PL-G., Grant Agreement no. 322669) and CALCYAN (PI KB, Grant Agreement no. 307110) under the European Union’s Seventh Framework Program and the RTP Génomique environnementale of the CNRS (project MetaStrom, PI DM

Exploring microbial life in the multi-extreme environment of Dallol, Ethiopia

Early Earth and ExoEarths: origin and evolution of life (2017. Varsovia)The Danakil depression at the Afar region in Ethiopia is one of the most unique and extreme environments on Earth. At the confluence of three tectonic plates in the East African rift (Triple Afar Junction), the Afar Depression is the only place on Earth where the transition from continental to oceanic crust (rift-to drift process) can be observed on land. Several types of extreme environments co-exist in this area, including highly acidic hydrothermal springs linked to the local volcanic activity at the Dallol dome, as well as desert evaporites and hypersaline lakes that resulted from the intense evaporation of an ancient enclosed sea. Although there have been more than 50 years since the area was first explored, information about its chemistry and geology is limited, and its biology remains completely unknown. In January 2016 and in January 2017, after several years of preparation, we organized two interdisciplinary expeditions to the Dallol area in order to explore the presence of life and mineral-microbe interactions under these geochemical extremes. To do so, and in combination with geochemical and mineralogical studies, we are applying molecular analyses based on 16S rRNA gene sequences, metagenomic and cultural approaches. Here, we will present preliminary results on the presence of life and microbial diversity identified in several sites of this multi-extreme environment.Centre National de la Recherche Scientifique, Université Paris-Sud, FranciaLaboratoire de microbiologie des environnements extrêmes, Centre National de la Recherche Scientifique, Université de Bretagne Occidentale, FranciaDepartamento de Ecología, Universidad Autónoma de Madrid, EspañaUnidad de Baleares, Instituto Geológico y Minero de España, EspañaInstituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas, EspañaInstituto Andaluz de Ciencias de la Tierra, Universidad de Granada, EspañaLaboratoire de Minéralogie, Physique des Matériaux et Cosmochimie , Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, FranciaPeer reviewe

Métodos de evaluación para las competencias generales más demandadas en el mercado laboral

Según las declaraciones de Bolonia [1] y de Bergen [2], el EEES pretende conseguir preparar al estudiante para el mercado laboral, proporcionándole competencias y formándole para una ciudadanía activa. Desde hace tiempo la formación en competencias transversales (también llamadas personales o generales) es una de las nuevas facetas que debe afrontar la educación universitaria. Pero ¿qué competencias se deben desarrollar?, ¿cómo hacerlo? y ¿cómo medir (evaluar) el nivel de competencia alcanzado? En este trabajo se estudiarán las demandas de competencias para los egresados en Informática, a partir de los datos obtenidos del análisis de ofertas de empleo publicadas en los principales periódicos nacionales, y la evolución que estos datos han sufrido a lo largo de los últimos años. Además se detallarán las características de las competencias más demandadas, a fin de esbozar posibles herramientas para desarrollarlas y evaluarlas en el alumnado, para terminar analizando los resultados de la implantación de la evaluación de competencias en un grupo de asignaturas técnicas

A theropod trackway providing evidence of a pathological foot from the exceptional locality of Las Hoyas (upper Barremian, Serranía de Cuenca, Spain)

We describe a trackway (LH-Mg-10-16) occurring in laminated carbonated limestones of the Las Hoyas locality, Serranía de Cuenca, Spain. It is unmistakably a large theropod dinosaur trackway encompassing two unusual aspects, namely, wide-steps, and a set of equally deformed left footprints (with a dislocated digit). The layer also preserves other vertebrate trails (fish Undichna) and different impressions in the sediment. To address these complex settings, we devised a multidisciplinary approach, including the ichnological and taphonomical descriptions, characterisation of the rock lithofacies using thin-sections, 3D structured-light digitalisation with a high precision of 200-400 μm, and a geometric morphometric comparison with a large sample of bipedal dinosaur trackways. Sedimentary analyses showed that the trackway was produced in a humid, benthonic microbial mat, the consistency and plasticity of which enabled the preservation of the details of the movement of the animal. The results of the geometric analysis indicate that the 'wide-steps' of the trackway is not unusual compared to other trackways, providing evidence that it was made by a single individual with an estimated hip height approximately 2 m. Analogous pathologies in extant archosaurs that yield the combination of wide steps and deformed digits in the same trackway were considered. All results mutually support the hypothesis that a large theropod dinosaur, with a pathological foot, generated the trackway as it crossed an area of shallow water while slowly walking towards the main water source, thus stepping steadily over the benthonic mat over which multiple fish were swimming

A theropod trackway providing evidence of a pathological foot from the exceptional locality of Las Hoyas (upper Barremian, Serrania de Cuenca, Spain)

We describe a trackway (LH-Mg-10-16) occurring in laminated carbonated limestones of the Las Hoyas locality, Serranı´a de Cuenca, Spain. It is unmistakably a large theropod dinosaur trackway encompassing two unusual aspects, namely, wide-steps, and a set of equally deformed left footprints (with a dislocated digit). The layer also preserves other vertebrate trails (fish Undichna) and different impressions in the sediment. To address these complex settings, we devised a multidisciplinary approach, including the ichnological and taphonomical descriptions, characterisation of the rock lithofacies using thin-sections, 3D structuredlight digitalisation with a high precision of 200–400 μm, and a geometric morphometric comparison with a large sample of bipedal dinosaur trackways. Sedimentary analyses showed that the trackway was produced in a humid, benthonic microbial mat, the consistency and plasticity of which enabled the preservation of the details of the movement of the animal. The results of the geometric analysis indicate that the “wide-steps” of the trackway is not unusual compared to other trackways, providing evidence that it was made by a single individual with an estimated hip height approximately 2 m. Analogous pathologies in extant archosaurs that yield the combination of wide steps and deformed digits in the same trackway were considered. All results mutually support the hypothesis that a large theropod dinosaur, with a pathological foot, generated the trackway as it crossed an area of shallow water while slowly walking towards the main water source, thus stepping steadily over the benthonic mat over which multiple fish were swimmin