Isotopic and hydrogeochemical characterization of high-altitude karst aquifers in complex geological settings. The Ordesa and Monte Perdido National Park (Northern Spain) case study.

The Ordesa and Monte Perdido National Park, located in the Southern Pyrenees, constitutes the highest karst system in Western Europe. No previous studies regarding its geochemical and isotopic groundwater characterization are available in this area. This work presents the results of field and sampling campaigns carried out between July 2007 and September 2013. The groundwater presents high calcium bicarbonate contents due to the occurrence of upper Cretaceous and lower Paleocene-Eocene carbonate materials in the studied area. Other relevant processes include dissolution of anhydrite and/or gypsum and incongruent dissolution of Mg-limestone and dolomite. The water stable isotopes (δ18O, δ2H) showthat the oceanic fronts from the Atlantic Ocean are responsible for the high levels of precipitation. In autumn, winter, and spring, a deuterium excess is found in the rechargewater,which could be related to local atmospheric transport of low-altitude snow sublimation vapour and its later condensation on the snowsurface at higher altitude,where recharge ismostly produced. The recharge zones are mainly between 2500mand 3200ma.s.l. The tritiumcontent of the water suggests short groundwater transit times. The isotopic composition of dissolved sulphate points to the existence of regional fluxes mixed with local discharge in some of the springs. This work highlights the major role played by the altitude difference between the recharge and discharge zones in controlling the chemistry and the vertical variability of the isotopic composition in high-altitude karst aquifers

Melanoma, ancestralidad y variantes MC1R en la población mestizada uruguaya

Malignant melanoma (MM) is the most dangerous type of skin cancer and the main cause of death produced by skin diseases. In Uruguay, the incidence rate is 3.8/100,000, one of the highest in Latin America. We analyzed the contribution of ancestry and MC1R as a candidate gene for sporadic melanoma in Uruguay. Our objective wasto investigate the possible associations between ancestry and the MC1R gene with sporadic melanoma in the Uruguayan population. To that end, one hundred patients with sporadic MM and 107 controls were recruited. Phenotypic factors and lifestyle were evaluated as risk factors. At the same time, we analyzed fiveancestry informative markers, the MC1R variants (R151, R160 and D294H) and five tag-SNPs. Phototype, atypical nevi, sunburns and recreational exposure were the main risk factors for MM in the Uruguayan population. We confirmed 16q as a candidate region for MM. R151C, and R160W showed an important association with risk of melanoma (OR= 3.85, P= 1 x 10-2; OR= 10.15, P= 7 x 10-3, respectively). Furthermore, three novel MC1R haplotypes from the promoter region were detected,and the two most common haplotypes for the coding region were different to the ones found in Europeans through HapMap. However, MC1R coding region haplotypes revealed a highly similar frequency to that of the Spanish population. Our results showed that the chromosomal 16q region confers susceptibility to MM risk in the Uruguayan population. In addition, the admixed genome structure of the MC1R region could be part of the explanation of melanoma etiology.El melanoma maligno (MM) es uno de los más peligrosos, y la principal causa de muerte producida por tumores de piel. En el Uruguay, la tasa de incidencia es de 3,8/100.000, una de las más altas de América Latina. En este trabajo analizamos la ancestría y el gen candidato MC1R entre los pacientes con MM del Uruguay. Nuestro objetivo fue investigar la posible asociación entre ancestría y el gen MC1R en pacientes con melanoma esporádico en la población uruguaya. Con tal finalidad, se reclutaron 100 pacientes con MM esporádico y 107 controles. Se evaluó el riesgo de factores fenotípicos y de estilo de vida. Además se analizaron cinco marcadores informativos de ancesdencia, variantes del gen MC1R (R151, R160 y D294H) y cinco tagSNPs. El fototipo, los nevos atípicos, quemaduras solares y la exposición recreativa fueron los principales factores de riesgo para MM en la población uruguaya. La región cromosómica 16q es candidata para MM, mientras que R151C y R160W mostraron una importante asociación con el riesgo para MM (OR= 3,85, P= 1 x 10-2; OR= 10,15, P= 7 x 10-3, respectivamente). Por otra parte, se detectaron tres nuevos haplotipos en la región promotora y los dos haplotipos más frecuentes en la región codificante son diferentes a los encontrados en la población europea. Sin embargo, los haplotipos de la región codificante presentan una frecuencia muy similar a las encontradas en la población española. Los resultados muestran que la región cromosómica 16q confiere susceptibilidad al riesgo de MM en la población uruguaya. Por otra parte, la estructura genómica mestizada de la región del MC1R podría explicar la etiología del melanoma

Bias in diet determination: Incorporating traditional methods in Bayesian mixing models

There are not "universal methods" to determine diet composition of predators. Most traditional methods are biased because of their reliance on differential digestibility and the recovery of hard items. By relying on assimilated food, stable isotope and Bayesian mixing models (SIMMs) resolve many biases of traditional methods. SIMMs can incorporate prior information (i.e. proportional diet composition) that may improve the precision in the estimated dietary composition. However few studies have assessed the performance of traditional methods and SIMMs with and without informative priors to study the predators' diets. Here we compare the diet compositions of the South American fur seal and sea lions obtained by scats analysis and by SIMMs-UP (uninformative priors) and assess whether informative priors (SIMMs-IP) from the scat analysis improved the estimated diet composition compared to SIMMs-UP. According to the SIMM-UP, while pelagic species dominated the fur seal's diet the sea lion's did not have a clear dominance of any prey. In contrast, SIMM-IP's diets compositions were dominated by the same preys as in scat analyses. When prior information influenced SIMMs' estimates, incorporating informative priors improved the precision in the estimated diet composition at the risk of inducing biases in the estimates. If preys isotopic data allow discriminating preys' contributions to diets, informative priors should lead to more precise but unbiased estimated diet composition. Just as estimates of diet composition obtained from traditional methods are critically interpreted because of their biases, care must be exercised when interpreting diet composition obtained by SIMMs-IP. The best approach to obtain a near-complete view of predators' diet composition should involve the simultaneous consideration of different sources of partial evidence (traditional methods, SIMM-UP and SIMM-IP) in the light of natural history of the predator species so as to reliably ascertain and weight the information yielded by each method

Relationship between the female attendance pattern and pup growth rate in the South American sea lion (Carnivora)

Changes in the duration and frequency of foraging trips by female otariids may result in changes in the duration and frequency of lactation bouts and hence influence pup growth rate, unless females modify milk energy density and/or the total amount of milk delivered depending on the trip duration. To test this hypothesis on South American sea lions, we measured two attendance pattern components (foraging trip and haul-out duration) and three diving behaviour components of nursing females (dive time, bottom time and number of dives per h) at two different rookeries in Uruguay and Argentina, the composition and energy density of their milk, and the growth rate of their pups. Female foraging trip and haul-out durations depended on pup sex and weight, whereas milk energy density depended on female body mass and foraging trip durations. By contrast, the three dive variables were independent of female body mass or pup sex. Pup growth was also independent of the foraging trip and haul-out duration, with pup sex as the only significant variable. This suggests that individual differences in female foraging behaviour play a minor role in determining pup growth rates during the first three weeks after birth

Insights into the genetic diversity of the leopard seal (Hydrurga leptonyx), inferred from mitochondrial DNa analysis, at Danco Coast, antarctic Peninsula

La foca leopardo (Hydrurga leptonyx) es una especie poco estudiada a nivel genético. Con el fin de realizar la primera evaluación de la diversidad genética de esta especie en la costa de Danco (Península Antártica), se secuenció 423 pb de la Región Control del ADN mitocondrial (ADNmt-CR) de 13 muestras de sangre colectadas en la Base Primavera (62º15’S, 58º39’W) durante el verano austral 2011-2012. Los resultados mostraron una alta diversidad de haplotipos (h = 0.99), con varios haplotipos divergentes. Nuestros hallazgos genéticos sugieren que las focas leopardo de la costa de Danco podrían representar diferentes filogrupos; sin embargo, es necesario incluir más marcadores genéticos para confirmar esta hipótesis.The leopard seal (Hydrurga leptonyx) is a genetically low-studied species. In order to conduct the first genetic diversity assessment of this species in Danco Coast (Antarctic Peninsula), 423 bp of the mitochondrial DNA Control Region (mtDNA-CR) was sequenced from 13 blood samples collected in Primavera Base (62°15'S, 58°39'W) during the 2011-2012 austral summer. Our results showed high haplotype diversity (h = 0.99), with various divergent haplotypes. Our findings suggest that leopard seals in the Danco Coast could represent different phylogroups; however, including more genetic markers are needed to confirm this hypothesis.Fil: Hernández Ardila, Laura Valentina. Universidad de los Andes; ColombiaFil: Barragán Barrera, Dalia C.. Universidad de los Andes; Colombia. Escuela Naval de Cadetes “Almirante Padilla”; Colombia. Fundación Macuático; Colombia. Comisión Colombiana del Océano; ColombiaFil: Negrete, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Poljak, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego, Antártida e Islas del Atlántico Sur. Instituto de Ciencias Polares, Ambientales y Recursos Naturales; ArgentinaFil: Riet Sapriza, Federico G.. Instituto Antártico Uruguayo; Uruguay. Universidad de los Andes; ColombiaFil: Caballero, Susana. Universidad de los Andes; Colombi

Assessing the relative importance of parameter and forcing uncertainty and their interactions in conceptual hydrological model simulations

Predictions of river flow dynamics provide vital information for many aspects of water management including water resource planning, climate adaptation, and flood and drought assessments. Many of the subjective choices that modellers make including model and criteria selection can have a significant impact on the magnitude and distribution of the output uncertainty. Hydrological modellers are tasked with understanding and minimising the uncertainty surrounding streamflow predictions before communicating the overall uncertainty to decision makers. Parameter uncertainty in conceptual rainfall-runoff models has been widely investigated, and model structural uncertainty and forcing data have been receiving increasing attention. This study aimed to assess uncertainties in streamflow predictions due to forcing data and the identification of behavioural parameter sets in 31 Irish catchments. By combining stochastic rainfall ensembles and multiple parameter sets for three conceptual rainfall-runoff models, an analysis of variance model was used to decompose the total uncertainty in streamflow simulations into contributions from (i) forcing data, (ii) identification of model parameters and (iii) interactions between the two. The analysis illustrates that, for our subjective choices, hydrological model selection had a greater contribution to overall uncertainty, while performance criteria selection influenced the relative intra-annual uncertainties in streamflow predictions. Uncertainties in streamflow predictions due to the method of determining parameters were relatively lower for wetter catchments, and more evenly distributed throughout the year when the Nash-Sutcliffe Efficiency of logarithmic values of flow (lnNSE) was the evaluation criterion

Photo-identification and satellite telemetry connect southern right whales from South Georgia Island (Islas Georgias del Sur) with multiple feeding and calving grounds in the southwest Atlantic

The sub-Antarctic waters of South Georgia Island (Islas Georgias del Sur, SG/IG) are a regularly visited feeding ground for southern right whales (Eubalaena australis, SRW) in the southwest Atlantic. Satellite telemetry and photo-identification records were compared to better understand the role of SG/IG in the SRW migratory network. We present the first insights from SRW satellite-tracked from the SG/IG feeding ground, habitat use patterns in the Scotia Arc, and movements to Antarctic habitats. Photo-identification comparisons to calving and feeding areas across the South Atlantic and a review of sightings of cetaceans reported from Bird Island (west of SG/IG) since 1979 illuminate long-term habitat use patterns in SG/IG. We present the first recorded migratory movement between SG/IG and multiple countries: Argentina, Uruguay, and Brazil. Photo-identification (1) linked SG/IG to a female SRW with a long-term sighting history in Brazil, and (2) provided the first match between SG/IG and the western Antarctic Peninsula, suggesting the latter could extend the feeding area for southwest Atlantic SRW. Satellite tracking and opportunistic sightings suggest that shelf and coastal waters west of SG/IG represent an important multi-season SRW feeding habitat and add to our overall understanding of habitats and ranges occupied by recovering southwest Atlantic SRW

Longer and less overlapping food webs in anthropogenically disturbed marine ecosystems: confirmations from the past

The human exploitation of marine resources is characterised by the preferential removal of the largest species. Although this is expected to modify the structure of food webs, we have a relatively poor understanding of the potential consequences of such alteration. Here, we take advantage of a collection of ancient consumer tissues, using stable isotope analysis and SIBER to assess changes in the structure of coastal marine food webs in the South-western Atlantic through the second half of the Holocene as a result of the sequential exploitation of marine resources by hunter-gatherers, western sealers and modern fishermen. Samples were collected from shell middens and museums. Shells of both modern and archaeological intertidal herbivorous molluscs were used to reconstruct changes in the stable isotopic baseline, while modern and archaeological bones of the South American sea lion Otaria flavescens, South American fur seal Arctocephalus australis and Magellanic penguin Spheniscus magellanicus were used to analyse changes in the structure of the community of top predators. We found that ancient food webs were shorter, more redundant and more overlapping than current ones, both in northern-central Patagonia and southern Patagonia. These surprising results may be best explained by the huge impact of western sealing on pinnipeds during the fur trade period, rather than the impact of fishing on fish populations. As a consequence, the populations of pinnipeds at the end of the sealing period were likely well below the ecosystem's carrying capacity, which resulted in a release of intraspecific competition and a shift towards larger and higher trophic level prey. This in turn led to longer and less overlapping food webs

Participación de la mujer en la industria del calzado en el Uruguay : una perspectiva histórica

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