El corrent d'Agulhas pot influir en el clima a Europa

Una tesi doctoral realitzada per Gema Martínez-Méndez, investigadora de l'Institut de Ciència i Tecnologia Ambientals (ICTA) de la UAB sobre el Corrent d'Agulhas, que transporta aigües càlides de l'Oceà Índic tropical cap a l'extrem sud d'Àfrica, aporta, per primera vegada, evidències a favor que els escapaments d'aigües d'aquest corrent cap a l'Atlàntic poden afectar el clima a Europa. Les dades oceàniques actuals no han permès verificar, fins ara, si la connexió entre el Corrent d'Agulhas al voltant de Sud Àfrica i el clima europeu existeix en realitat. La investigadora de l'ICTA ha estat premiada per les seves aportacions en la darrera reunió de l'American Geophysical Union (AGU).Una tesis doctoral realizada por Gema Martínez-Méndez, investigadora del Institut de Ciència i Tecnología Ambientals (ICTA) de la Universitat Autònoma de Barcelona (UAB), sobre la corriente de Agulhas, que transporta aguas cálidas desde el Océano Índico tropical hacia el extremo sur de África, aporta, por primera vez, evidencias a favor de que las fugas de aguas de esta corriente hacia el Atlántico pueden afectar al clima en Europa. Los datos oceánicos actuales no han permitido verificar hasta ahora si la conexión entre la Corriente de Agulhas alrededor de Sudáfrica y el clima europeo existe en realidad. La investigadora del ICTA ha sido premiada por sus aportaciones en la última reunión de la American Geophysical Union (AGU).The PhD project presented by Gema Martínez-Méndez from the Institute of Environmental Science and Technology (ICTA) at the UAB focuses on the Agulhas Current and the ensuing warm water transports from the tropical Indian Ocean to the southern tip of Africa. The data generated provide for the first time evidence in support of the hypothesis that the Agulhas water "leakage" into the Atlantic can affect the climate in Europe. Measurements in the ocean so far have not permitted to test if a connection between the Agulhas Current around South Africa and the climate in Europe indeed exists. ICTA researcher Gema Martínez- Méndez recently received an award for her presentation in the fall meeting of the American Geophysical Union (AGU)

Variedades locales de maíz de Cantabria

136 Pags., con Figs., Tabls., Fots., Fichas.En las últimas décadas está desapareciendo gran parte de la biodiversidad agrícola mundial generada a lo largo de la historia de la agricultura. Esta pérdida de recursos fitogenéticos está relacionada principalmente con la sustitución masiva de multitud de variedades tradicionales por variedades comerciales genéticamente uniformes y con la progresiva unificación de hábitos culturales y alimenticios de la población mundial. Este proceso conocido como erosión genética, merma peligrosamente el patrimonio disponible para la selección natural y para la selección dirigida por parte de agricultores y técnicos. A su vez, esta tendencia genera un aumento de la vulnerabilidad de los cultivos agrícolas actuales, a los cambios ambientales y a la aparición de nuevas plagas y enfermedades.En este contexto, la conservación de los recursos fitogenéticos locales está permitiendo la recuperación del cultivo de especies o variedades tradicionales que vuelven a ser valoradas en la actualidad (por ejemplo en sistemas de agricultura ecológica) o que podrían serlo en el futuro ante un cambio ideológico en las prioridades productivas. Así mismo, esta conservación puede favorecer la seguridad alimentaria frente a la aparición de nuevas plagas o enfermedades o frente a cambios en las condiciones ambientales, a la vez que aumenta la disponibilidad de los recursos necesarios en el futuro para la mejora genética de los cultivos. No hay que olvidar que estos recursos fitogenéticos locales forman parte de nuestro patrimonio sociocultural y pueden ser importantes para el desarrollo sostenible de las generaciones venideras.En Cantabria, las condiciones climáticas y orográficas han permitido la existencia de un importante patrimonio relacionado con los recursos fitogenéticos, tanto dentro de las especies silvestres como de las variedades agrícolas tradicionales. Aunque una buena parte de esta diversidad ya se ha perdido, los inventarios nacionales del Centro de Recursos Fitogenéticos (CRF-INIA), accesibles vía Internet (http://wwwx.inia.es/webcrf/), conservan registradas 812 entradas prospectadas en Cantabria. Buena parte de ellas, en concreto 379 entradas, pertenecen al género Zea, es decir, el maíz, lo que nos da una idea de la implantación y diversidad del cultivo en la región en el pasado. Parte de estas entradas, en concreto 72, prospectadas en distintas localidades de Cantabria en las décadas de los sesenta, setenta y ochenta del siglo pasado, y cultivadas en el Centro de Investigación y Formación Agrarias (CIFA) de Muriedas en el año 2010, son las que se presentan en esta publicación, acompañadas de una descripción morfológica y fotografías actuales, como muestra del patrimonio genético agrícola de nuestra región, con el objetivo final de ampliar su conocimiento y puesta en valor.Este trabajo se ha realizado en el marco del proyecto regional del Gobierno de Cantabria “Caracterización de variedades locales de maiz de Cantabria” y del proyecto RF2010-00004-C04-01, financiado por el INIA, Programa Nacional de Recursos y Tecnología Agroalimentarias.Peer reviewe

Isotopic Characterization of Water Masses in the Southeast Pacific Region: Paleoceanographic Implications

In this study, we used stable isotopes of oxygen (δ18O), deuterium (δD), and dissolved inorganic carbon (δ13CDIC) in combination with temperature, salinity, oxygen, and nutrient concentrations to characterize the coastal (71°–78°W) and an oceanic (82°–98°W) water masses (SAAW—Subantarctic Surface Water; STW—Subtropical Water; ESSW—Equatorial Subsurface water; AAIW—Antarctic Intermediate Water; PDW—Pacific Deep Water) of the Southeast Pacific (SEP). The results show that δ18O and δD can be used to differentiate between SAAW-STW, SAAW-ESSW, and ESSW-AAIW. δ13CDIC signatures can be used to differentiate between STW-ESSW (oceanic section), SAAW-ESSW, ESSW-AAIW, and AAIW-PDW. Compared with the oceanic section, our new coastal section highlights differences in both the chemistry and geometry of water masses above 1,000 m. Previous paleoceanographic studies using marine sediments from the SEP continental margin used the present-day hydrological oceanic transect to compare against, as the coastal section was not sufficiently characterized. We suggest that our new results of the coastal section should be used for past characterizations of the SEP water masses that are usually based on continental margin sediment samples

Sphingolipid extracts enhance gene delivery of cationic lipid vesicles into retina and brain

[EN]The aim was to evaluate relevant biophysic processes related to the physicochemical features and gene transfection mechanism when sphingolipids are incorporated into a cationic niosome formulation for non-viral gene delivery to central nervous system. For that, two formulations named niosphingosomes and niosomes devoid of sphingolipid extracts, as control, were developed by the oil-in water emulsion technique. Both formulations and the corresponding complexes, obtained upon the addition of the reporter EGFP plasmid, were physicochemically and biologically characterized and evaluated. Compared to niosomes, niosphingosomes, and the corresponding complexes decreased particle size and increased superficial charge. Although there were not significant differences in the cellular uptake, cell viability and transfection efficiency increased when human retinal pigment epithelial (ARPE-19) cells were exposed to niosphingoplexes. Endocytosis via caveolae decreased in the case of niosphingoplexes, which showed higher co-localization with lysosomal compartment, and endosomal escape properties. Moreover, niosphingoplexes transfected not only primary central nervous system cells, but also different cells in mouse retina, depending on the administration route, and brain cortex. These preliminary results suggest that niosphingosomes represent a promising non-viral vector formulation purposed for the treatment of both retinal and brain diseases by gene therapy approach.This work was supported by the Basque Country Government (Department of Education, University and Research, Consolidated Groups IT907-16) . Additional funding was provided by the CIBER of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) , an initiative of the Carlos III Health Institute (ISCIII) . I.V.B. and M.S.R. thank the University of the Basque Country (UPV/EHU) for the granted postdoctoral fellowship (ESPDOC19/47) and the granted pre-doctoral fellowship (PIF17/79) , respectively. Authors wish to thank the intel-lectual and technical assistance from the ICTS "NANBIOSIS," more specifically by the Drug Formulation Unit (U10) of the CIBER in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) at the University of Basque Country (UPV/EHU) . Technical and human sup-port provided by SGIKER (UPV/EHU) is also gratefully acknowledged

Niosome-Based Approach for In Situ Gene Delivery to Retina and Brain Cortex as Immune-Privileged Tissues

Non-viral vectors have emerged as a promising alternative to viral gene delivery systems due to their safer profile. Among non-viral vectors, recently, niosomes have shown favorable properties for gene delivery, including low toxicity, high stability, and easy production. The three main components of niosome formulations include a cationic lipid that is responsible for the electrostatic interactions with the negatively charged genetic material, a non-ionic surfactant that enhances the long-term stability of the niosome, and a helper component that can be added to improve its physicochemical properties and biological performance. This review is aimed at providing recent information about niosome-based non-viral vectors for gene delivery purposes. Specially, we will discuss the composition, preparation methods, physicochemical properties, and biological evaluation of niosomes and corresponding nioplexes that result from the addition of the genetic material onto their cationic surface. Next, we will focus on the in situ application of such niosomes to deliver the genetic material into immune-privileged tissues such as the brain cortex and the retina. Finally, as future perspectives, non-invasive administration routes and different targeting strategies will be discussed.This work was supported by the Basque Country Government (Department of Education, University and Research, pre-doctoral grant PRE_2016_2_0302 and Consolidated Groups IT907-16). Additional funding was provided by the University of Basque Country UPV/EHU (predoctoral grant PIF17/19), the CIBER of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), and initiative of the Carlos III Health Institute (ISCIII)

Ejercicios Resueltos y supuestos prácticos

A continuación se presentan un conjunto de ejercicios y supuestos prácticos para que el alumno se familiarice con el tipo de actividades que debe realizar para alcanzar los objetivos y adquirir las competencias asociadas a cada uno de los temas relacionados con las técnicas de búsqueda yuso de la información propuestas en este libro

Contrasting multiproxy reconstructions of surface ocean hydrography in the Agulhas Corridor and implications for the Agulhas Leakage during the last 345,000 years

Planktonic δ18O and Mg/Ca-derived sea surface temperature (SST) records from the Agulhas Corridor off South Africa display a progressive increase of SST during glacial periods of the last three climatic cycles. The SST increases of up to 4°C coincide with increased abundance of subtropical planktonic foraminiferal marker species which indicates a progressive warming due to an increased influence of subtropical waters at the core sites. Mg/Ca-derived SST maximizes during glacial maxima and glacial Terminations to values about 2.5°C above full-interglacial SST. The paired planktonic δ18O and Mg/Ca-derived SST records yield glacial seawater δ18O anomalies of up to 0.8‰, indicating measurably higher surface salinities during these periods. The SST pattern along our record is markedly different from a U37K'-derived SST record at a nearby core location in the Agulhas Corridor that displays SST maxima only during glacial Terminations. Possible explanations are lateral alkenone advection by the vigorous regional ocean currents or the development of SST contrasts during glacials in association with seasonal changes of Agulhas water transports and lateral shifts of the Agulhas retroflection. The different SST reconstructions derived from U37K' and Mg/Ca pose a significant challenge to the interpretation of the proxy records and demonstrate that the reconstruction of the Agulhas Current and interocean salt leakage is not as straightforward as previously suggested

Automatic Discrimination of Species within the Enterobacter cloacae Complex Using Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry and Supervised Algorithms

The Enterobacter cloacae complex (ECC) encompasses heterogeneous clusters of species that have been associated with nosocomial outbreaks. These species may have different acquired antimicrobial resistance and virulence mechanisms, and their identification is challenging. This study aims to develop predictive models based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) profiles and machine learning for species-level identification. A total of 219 ECC and 118 Klebsiella aerogenes clinical isolates from three hospitals were included. The capability of the proposed method to differentiate the most common ECC species (Enterobacter asburiae, Enterobacter kobei, Enterobacter hormaechei, Enterobacter roggenkampii, Enterobacter ludwigii, and Enterobacter bugandensis) and K. aerogenes was demonstrated by applying unsupervised hierarchical clustering with principal-component analysis (PCA) preprocessing. We observed a distinctive clustering of E. hormaechei and K. aerogenes and a clear trend for the rest of the ECC species to be differentiated over the development data set. Thus, we developed supervised, nonlinear predictive models (support vector machine with radial basis function and random forest). The external validation of these models with protein spectra from two participating hospitals yielded 100% correct species-level assignment for E. asburiae, E. kobei, and E. roggenkampii and between 91.2% and 98.0% for the remaining ECC species; with data analyzed in the three participating centers, the accuracy was close to 100%. Similar results were obtained with the Mass Spectrometric Identification (MSI) database developed recently (https://msi.happy-dev.fr) except in the case of E. hormaechei, which was more accurately identified with the random forest algorithm. In short, MALDI-TOF MS combined with machine learning was demonstrated to be a rapid and accurate method for the differentiation of ECC species

Reversed flow of Atlantic deep water during the Last Glacial Maximum

The meridional overturning circulation (MOC) of the Atlantic Ocean is considered to be one of the most important components of the climate system. This is because its warm surface currents, such as the Gulf Stream, redistribute huge amounts of energy from tropical to high latitudes and influence regional weather and climate patterns, whereas its lower limb ventilates the deep ocean and affects the storage of carbon in the abyss, away from the atmosphere. Despite its significance for future climate, the operation of the MOC under contrasting climates of the past remains controversial. Nutrient-based proxies1, 2 and recent model simulations3 indicate that during the Last Glacial Maximum the convective activity in the North Atlantic Ocean was much weaker than at present. In contrast, rate-sensitive radiogenic 231Pa/230Th isotope ratios from the North Atlantic have been interpreted to indicate only minor changes in MOC strength4, 5, 6. Here we show that the basin-scale abyssal circulation of the Atlantic Ocean was probably reversed during the Last Glacial Maximum and was dominated by northward water flow from the Southern Ocean. These conclusions are based on new high-resolution data from the South Atlantic Ocean that establish the basin-scale north to south gradient in 231Pa/230Th, and thus the direction of the deep ocean circulation. Our findings are consistent with nutrient-based proxies and argue that further analysis of 231Pa/230Th outside the North Atlantic basin will enhance our understanding of past ocean circulation, provided that spatial gradients are carefully considered. This broader perspective suggests that the modern pattern of the Atlantic MOC—with a prominent southerly flow of deep waters originating in the North Atlantic—arose only during the Holocene epoch

Understanding the impacts of contaminant and pathogen flow through marine food webs

ICES Annual Science Conference 2021, 6–10 September, Virtual conferenceN