Climatología y reconstrucción de series temporales de descarga fluvial en el Noroeste de Iberia: influencia en el balance de densidad sobre la plataforma

River runoff off northwest Iberia generates a low-density buoyant structure with a strong influence on shelf and coastal circulation. This study estimates the runoff to the shelf of the ten largest rivers in the region based on the furthest downstream gauge records available, and also takes into account the basin area downstream from the station (22% of the basin area for the entire study region). Monthly statistics were computed to obtain mean values for each river to cover the recurrent lack of runoff data in the region. In order to reconstruct gaps in the time series on a daily scale, a method based on the observed discharge of a nearby river basin was used. In addition, the influence of runoff on the shelf was analyzed using monthly CTD data sampled during a 12-year period in the Ría de Vigo and the adjacent shelf. The CTD series shows the existence of a buoyant structure with maximum growth during winter and with large variability of its thermal anomaly. The salinity anomaly correlated significantly with mean winter monthly values of the North Atlantic Oscillation (NAO) index. This atmospheric index integrates both the influence of precipitation —and therefore runoff— and the predominant winds during winter that contribute to the accumulation of fresh water over the shelf.La descarga fluvial en el Noroeste de la Península Ibérica genera una estructura de baja densidad con altas implicaciones en la circulación costera y de plataforma. Este estudio estima la descarga fluvial en la plataforma para los 10 ríos más caudalosos en la región, utilizando para ello los registros de caudal disponibles y suplementados para tener en cuenta el área de la cuenca que se encuentra aguas abajo de las estaciones de aforo (~22% del área total de la región de estudio). Se han calculado valores medios mensuales para cada río, que resultan útiles para cubrir la recurrente carencia de datos en la región de estudio. Para reconstruir huecos en las series temporales en una escala diaria, se utiliza un simple método basado en las observaciones realizadas en una cuenca cercana. La influencia de la descarga fluvial sobre la hidrología en la plataforma es analizada mediante datos mensuales de CTD muestreados en la Ría de Vigo y la plataforma adyacente durante los últimos 12 años. Las series temporales de CTD muestran plumas de agua dulce con máximo crecimiento durante el invierno y con gran variabilidad en su estructura térmica. La correlación de la anomalía de densidad con valores medio invernales del índice de la Oscilación del Atlántico Norte (NAO) muestra valores significativos. Este patrón atmosférico es representativo de la influencia de la precipitación —y por tanto, la descarga fluvial— y los vientos predominantes durante el invierno, que contribuyen a la acumulación de agua dulce sobre la plataforma

Potential energy surface and spectroscopy of clusters of rare-gas atoms with cyclopropane

Analytical empirical potential energy surfaces describing the van der Waals interaction between rare-gas atoms and cyclopropane are presented. The functional form is based on pairwise Lennard-Jones-type potentials which have been widely used to describe rare-gas-benzene complexes, also studied in this work in order to check our theoretical method and for comparison. The parameters have been chosen in order to accurately fit the high resolution microwave spectra recently reported by Xu and Jäger [J. Chem. Phys. 106, 7968 (1997)]. The observed splitting in the microwave spectra of Ne-cyclopropane, associated with rotational tunneling, is well reproduced. Moreover, such tunneling is also important for complexes of Ar and Kr in excited van der Waals states. These phenomena involve a high delocalization of the wave functions and, therefore, intermolecular spectroscopy techniques would provide a good check of the potential energy surface over a broad region of the configuration space. © 1998 American Institute of Physics.This work has been supported by Consejería de Educación, Cultura y Deportes del Gobierno de Canarias under Grant No. PI 2/95, DGYCIT (Spain) under Grant No. PB95- 0071, and by the European TMR network Contract No. ERBFMRX-CT96-0088.Peer Reviewe

Bioprospection of cellulose-decomposers soil bacteria / Bioprospecção de bactérias do solo degradadoras de celulose

Soil microorganisms have a high bacterial biodiversity and an important group is the cellulose-decomposers bacteria, which through their endoglucanases, exoglucanases and ?-glycosidases enzymatic complexes are responsible for the planet organic biomass degradation. Therefore, to understand and apply their potentials in the biotechnology area, is necessary to know their biologic, biochemical and environmental characteristics and proprieties of the microorganisms involved in these degradation processes. Ten bacteria isolates where obtained. To verify the degradation, the filter paper and solid medium Luria-Bertani was used. In the extracellular enzymatic production analysis, the substrate used was the Whatman N°1 filter paper for the ß-1,4 exoglucanase and carboxymethyl cellulose for the ß-1,4 endoglucanase. Also the microbial biomass analysis was made. The results showed that, the most effective cellulose degradation isolates having as substrates, the BC5 and the BC2 bacteria respectively. In the endoglucanase ß-1,4 enzymatic activity was the BC5 and for the ß-1,4 exoglucanase was the BC8, meanwhile for the microbial biomass production, the best result was for the BC9 isolate bacteria. The results showed that between the different bacteria species from the different locals, significant differences were presented, when each of the analysis were compared and therefore this can be associated to the different types of ecosystems and to the biochemical and environmental characteristics in each type of soil, having different mechanisms directly related with the cellulose degradation. Therefore, these microorganisms have a potential use in diverse biotechnological and bioremediation cellulose degradation processes.

Evaluation of the effectiveness of ixodicides on Rhipicephalus (Boophilus) microplus in bovinos in a population of the state of Nuevo León, Mexico / Avaliação da eficácia de ixodicides em Rhipicephalus (Boophilus) microplus em bovinos em uma população do estado de Nuevo León, México

The Rhipicephalus (Boophilus) microplus tick is of great importance in livestock due to its direct and indirect effects, it has a distribution of 69.4% of the national territory, with approximate losses of up to 573.61 million dollars per year in Mexico. Chemical control is the most widely used method, however, continuous, and indiscriminate use has led to the emergence of populations of resistant ticks. In this study, the efficacy of three synthetic ixodicides, a pyrethroid, an organophosporade, and a pyrethroid- organophosporade mixture were evaluated. in a field population through the adult immersion test, obtaining efficacy rates of 28.66%, 100%, and 96%, respectively. It was obtained that the organophosphate is the only ixodicide that can be used in this population.

Examination of the Feynman-Hibbs Approach in the Study of NeN_N-Coronene Clusters at Low Temperatures

Feynman-Hibbs (FH) effective potentials constitute an appealing approach for investigations of many-body systems at thermal equilibrium since they allow us to easily include quantum corrections within standard classical simulations. In this work we apply the FH formulation to the study of Ne$_N$-coronene clusters ($N=$ 1-4, 14) in the 2-14 K temperature range. Quadratic (FH2) and quartic (FH4) contributions to the effective potentials are built upon Ne-Ne and Ne-coronene analytical potentials. In particular, a new corrected expression for the FH4 effective potential is reported. FH2 and FH4 cluster energies and structures -obtained from energy optimization through a basin-hoping algorithm as well as classical Monte Carlo simulations- are reported and compared with reference path integral Monte Carlo calculations. For temperatures $T> 4$ K, both FH2 and FH4 potentials are able to correct the purely classical calculations in a consistent way. However, the FH approach fails at lower temperatures, especially the quartic correction. It is thus crucial to assess the range of applicability of this formulation and, in particular, to apply the FH4 potentials with great caution. A simple model of $N$ isotropic harmonic oscillators allows us to propose a means of estimating the cut-off temperature for the validity of the method, which is found to increase with the number of atoms adsorbed on the coronene molecule

Coronene molecules in helium clusters: Quantum and classical studies of energies and configurations

Under the terms of the Creative Commons Attribution (CC BY) license to their work.Coronene-doped helium clusters have been studied by means of classical and quantum mechanical (QM) methods using a recently developed He–C24H12 global potential based on the use of optimized atom-bond improved Lennard-Jones functions. Equilibrium energies and geometries at global and local minima for systems with up to 69 He atoms were calculated by means of an evolutive algorithm and a basin-hopping approach and compared with results from path integral Monte Carlo (PIMC) calculations at 2 K. A detailed analysis performed for the smallest sizes shows that the precise localization of the He atoms forming the first solvation layer over the molecular substrate is affected by differences between relative potential minima. The comparison of the PIMC results with the predictions from the classical approaches and with diffusion Monte Carlo results allows to examine the importance of both the QM and thermal effects.This work has been supported by MICINN Grant Nos. FIS2011-29596-C02-01, FIS2013-48275-C2-1-P, and FIS2014-51993-P. R.R.-C. acknowledges funding from the Grant No. JAE-Pre-2010-01277. J.H.-R. and J.B. acknowledge the financial support from Ministerio de Economía y Competitividad under Grant No. FIS2013-41532-P.Peer reviewe

Natural Variation in Diauxic Shift between Patagonian Saccharomyces eubayanus Strains

The study of natural variation can untap novel alleles with immense value for biotechnological applications. Saccharomyces eubayanus Patagonian isolates exhibit differences in the diauxic shift between glucose and maltose, representing a suitable model to study their natural genetic variation for novel strains for brewing. However, little is known about the genetic variants and chromatin regulators responsible for these differences. Here, we show how genome-wide chromatin accessibility and gene expression differences underlie distinct diauxic shift profiles in S. eubayanus. We identified two strains with a rapid diauxic shift between glucose and maltose (CL467.1 and CBS12357) and one strain with a remarkably low fermentation efficiency and longer lag phase during diauxic shift (QC18). This is associated in the QC18 strain with lower transcriptional activity and chromatin accessibility of specific genes of maltose metabolism and higher expression levels of glucose transporters. These differences are governed by the HAP complex, which differentially regulates gene expression depending on the genetic background. We found in the QC18 strain a contrasting phenotype to those phenotypes described in S. cerevisiae, where hap4D, hap5D, and cin5D knockouts significantly improved the QC18 growth rate in the glucose-maltose shift. The most profound effects were found between CIN5 allelic variants, suggesting that Cin5p could strongly activate a repressor of the diauxic shift in the QC18 strain but not necessarily in the other strains. The differences between strains could originate from the tree host from which the strains were obtained, which might determine the sugar source preference and the brewing potential of the strain.Fil: Molinet, Jennifer. Universidad de Santiago de Chile; ChileFil: Eizaguirre, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; ArgentinaFil: Quintrel, Pablo. Universidad de Santiago de Chile; ChileFil: Bellora, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Instituto de Tecnologías Nucleares para la Salud; ArgentinaFil: Villarroel, Carlos A.. Universidad de Talca; ChileFil: Villarreal, Pablo. Universidad de Santiago de Chile; ChileFil: Benavides Parra, José. Universidad de Santiago de Chile; ChileFil: Nespolo, Roberto F.. Universidad Austral de Chile; ChileFil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; ArgentinaFil: Cubillos, Francisco A.. Universidad de Santiago de Chile; Chil

Identification of miR-660-5p targets involved in breast cancer progression

Background: Breast cancer (BC) is the most diagnosed cancer in women globally. MicroRNAs (miRNAs) participate in different processes of BC; their deregulation can make them act as oncogenes or tumor suppressors, participating in cancer progression. Using the TCGA (The Cancer Genome Atlas) database, we found miR-660-5p significantly overexpressed and associated with poor survival in patients with this pathology. It is reported that miR-660-5p induces proliferation, migration, and invasion in BC. However, the specific targets of this miRNA that induce each of these processes are unknown. In this project we propose to identify the targets of miR-660-5p involved in proliferation, migration, invasion, and angiogenesis in BC cells. Methods: The basal levels of miR-660-5p were determined by RT-qPCR. The effect of miR-660-5p was evaluated on proliferation, invasion, and migration processes in MDA-MB-231 and MCF-7 cells, and angiogenesis in HUVEC cells transfected with the miR-660-5p inhibitor. We identified targets of miR-660-5p using different databases, and we evaluated their expression by RT-qPCR in plate. Results: In this study, we found that miR-660-5p is significantly upregulated in BC cells MDA-MB-231 and MCF-7, compared to normal breast cells MCF-10A. In addition, we observed a significantly decrease in the processes of proliferation, migration, and invasion in BC cells, compared to untreated cells and negative control group. Similarly, we observed a significantly decrease in the angiogenesis process in HUVEC cells, compared to untreated cells and negative control group. Likewise, by analyzing the different databases and the literature, we found a total of 28 miR-660-5p targets involved in oncological processes. Conclusions: miR-660-5p is overexpressed in BC cells compared to healthy breast cells. Furthermore, miR-660-5p induces the processes of proliferation, migration and invasion in BC cells, and angiogenesis in HUVEC cells

Range-Expanding Populations of a Globally Introduced Weed Experience Negative Plant-Soil Feedbacks

BACKGROUND: Biological invasions are fundamentally biogeographic processes that occur over large spatial scales. Interactions with soil microbes can have strong impacts on plant invasions, but how these interactions vary among areas where introduced species are highly invasive vs. naturalized is still unknown. In this study, we examined biogeographic variation in plant-soil microbe interactions of a globally invasive weed, Centaurea solstitialis (yellow starthistle). We addressed the following questions (1) Is Centaurea released from natural enemy pressure from soil microbes in introduced regions? and (2) Is variation in plant-soil feedbacks associated with variation in Centaurea's invasive success? METHODOLOGY/PRINCIPAL FINDINGS: We conducted greenhouse experiments using soils and seeds collected from native Eurasian populations and introduced populations spanning North and South America where Centaurea is highly invasive and noninvasive. Soil microbes had pervasive negative effects in all regions, although the magnitude of their effect varied among regions. These patterns were not unequivocally congruent with the enemy release hypothesis. Surprisingly, we also found that Centaurea generated strong negative feedbacks in regions where it is the most invasive, while it generated neutral plant-soil feedbacks where it is noninvasive. CONCLUSIONS/SIGNIFICANCE: Recent studies have found reduced below-ground enemy attack and more positive plant-soil feedbacks in range-expanding plant populations, but we found increased negative effects of soil microbes in range-expanding Centaurea populations. While such negative feedbacks may limit the long-term persistence of invasive plants, such feedbacks may also contribute to the success of invasions, either by having disproportionately negative impacts on competing species, or by yielding relatively better growth in uncolonized areas that would encourage lateral spread. Enemy release from soil-borne pathogens is not sufficient to explain the success of this weed in such different regions. The biogeographic variation in soil-microbe effects indicates that different mechanisms may operate on this species in different regions, thus establishing geographic mosaics of species interactions that contribute to variation in invasion success

Oxidative damage in tissues of juvenile crayfish (Cherax quadricarinatus von Martens, 1868) fed with different levels of proteins and lipid

This experiment investigated the effect of dietary protein and lipid levels on superoxide radical production and lipid peroxidation in juvenile redclaw crayfish, Cherax quadricarinatus. Nine practical diets were formulated to contain a combination of three crude protein (CP) (26, 31, and 36%) and three crude lipid (CL) (4, 8, and 12%) levels. Four replicate was fed with a commercial shrimp diet. After the feeding period, superoxide radical (O2 ?) production and lipid peroxidation, measured as thiobarbituric acid reactive substances (TBARS) of muscle, digestive gland and gill were analyzed. In the group fed the control diet, O2 ? production and TBARS levels were significantly higher in the digestive gland than in muscles or gills. There was no effect of dietary protein or lipid level on O2 ? production in the digestive gland, muscle, and gill. However, dietary protein level significantly affected TBARS levels in crayfish gills (p < 0.05). The results suggest tissue-specific effects of dietary protein and lipid levels on indicators of oxidative stress in redclaw. Results indicate that a diet containing 31% CP and 8% CL provided adequate amounts of protein and lipid to satisfy nutritional requirements for optimal growth, while preventing diet-induced oxidative stress and protecting the integrity of the immune function