Identificación de epítopes T citotóxicos restringidos a la molécula HLA-A2.1 en la proteína HSP70 de T. cruzi.

El análisis de la capacidad de unión a células T2 realizado con 31 péptidos correspondientes a distintas regiones dela proteína HSP70 de Trypanosoma cruzi, muestra que 14 de estos péptidos tienen una alta o media afinidad por lamolécula presentadora A2.1. Interesantemente, el presente manuscrito pone de manifiesto que la inmunización deratones transgénicos A2/Kb con la proteína recombinante HSP70 de T. cruzi induce CTLs que reconocen células EL4-A2/Kb cargadas de forma independiente con tres de los péptidos con afinidad de unión a moléculas A2. Estospéptidos presentan una homología menor del 65% con sus homólogos de la proteína HSP70 humana. Los resultadosobtenidos permiten sugerir la posibilidad de que la HSP70 de T. cruzi pueda ser usada como diana para induciractividad inmune citotóxica en humanos

Astronomía: una experiencia

Desde el año 2001 se desarrolla en la EEM N° 31 Libertador General Don José de San Martín de La Plata el Taller de Astronomía y Ciencias del Espacio. En dicho año fue seleccionado como proyecto innovador en el llamado que realizó el Ministerio de Educación de la Nación en el marco del PRODYMES II. El objetivo del proyecto es la difusión de la astronomía dentro del establecimiento, acercando al alumno a la ciencia por medio de diferentes actividades: observación del cielo, manejo del telescopio, obtención de fotografías, asistencia a encuentros semanales, el boletín astronómico y participación en las exposiciones realizadas en el colegio. Posteriormente se incluyeron nuevas actividades, relacionadas con la actividad espacial inscribiendo al establecimiento en proyectos de la NASA y en programas de la ESA (agencia espacial europea). La experiencia recogida durante estos años muestra que los alumnos se comprometen con las distintas actividades del taller, para muchos de ellos se abre un mundo desconocido comienzan a observar el cielo y comparten con sus compañeros los conocimientos adquiridos.Departamento de Ciencias Exactas y Naturale

Plant species influence on soil C after afforestation of Mediterranean degraded soils

6 figuras.-- Poster presentado en Geophysical Research Abstracts Vol. 17, EGU2015-12121, 2015Increasing C sequestration in terrestrial ecosystems is one of the main current environmental challenges to mitigate climate change. Afforestation of degraded and contaminated lands is one of the key strategies to achieve an increase in C sequestration in ecosystems. Plant species differ in their mechanisms of C-fixation, C allocation into different plant organs, and interaction with soil microorganisms, all these factors influencing the dynamics of soil C following the afforestation of degraded soils. In this work we examine the influence of different woody plant species on soil C dynamics in degraded and afforested Mediterranean soils. The soils were former agricultural lands that were polluted by a mining accident and later afforested with different native plant species. We analysed the effect of four of these species (Olea europaea var. sylvestris Brot., Populus alba L., Pistacia lentiscus L. and Retama sphaerocarpa (L.) Boiss.) on different soil C fractions, soil nutrient availability, microbial activity (soil enzyme activities) and soil CO2 fluxes 15 years after the establishment of the plantations. Results suggest that the influence of the planted trees and shrubs is still limited, being more pronounced in the more acidic and nutrient-poor soils. Litter accumulation varied among species, with the highest C accumulated in the litter under the deciduous species (Populus alba L.). No differences were observed in the amount of total soil organic C among the studied species, or in the concentrations of phenols and sugars in the dissolved organic C (DOC), which might have indicated differences in the biodegradability of the DOC. Microbial biomass and activity was highly influenced by soil pH, and plant species had a significant influence on soil pH in the more acidic site. Soil CO2 fluxes were more influenced by the plant species than total soil C content. Our results suggest that changes in total soil C stocks after the afforestation of degraded Mediterranean soils are hardly detectable at decadal time-scales, and that more dynamic pools and fluxes must be monitored to determine which plant species should be promote to enhance C sequestration capacity.The RECARE project is funded by the European Commission FP7 Programme, ENV.2013.6.2-4 "Sustainable land care in Europe". EU grant agreement: 603498.Peer reviewe

Effects of soil contamination by trace elements on white poplar progeny: seed germination and seedling vigour

11 páginas.-- 2 figuras.-- 2 tablas.-- 62 referencias.-- Electronic supplementary material in the online version of this article (doi:10.​1007/​s10661-015-4893-8) contains supplementary material, which is available to authorized users.Seed germination is considered a critical phase in plant development and relatively sensitive to heavy metals. White poplar (Populus alba) trees tend to accumulate Cd and Zn in their tissues. We tested if soil contamination can affect P. alba progeny, reduced seed germination and explored the distribution of mineral elements in the seed. For this purpose, fruits and seeds from female P. alba trees were selected from two contaminated and one non-contaminated areas. Seeds from all the sites were germinated using only water or a nutritive solution (in vitro). Concentrations of nutrients and trace elements in the fruits and seeds were analysed. Seedling growth in vitro was also analysed. Finally, a mapping of different elements within the poplar seed was obtained by particle-induced X-ray emission (PIXE). Germination was similar between different progenies, refuting our hypothesis that seeds from a contaminated origin would have reduced germination capacity compared to those from a non-contaminated site. Seedling growth was not affected by the contaminated origin. Cadmium and Zn concentrations in fruits produced by P. alba trees in the contaminated sites were higher than by those from the non-contaminated site. However, the nutritional status of the trees was adequate in both cases. Cd in seedlings was higher in those from contaminated soils although lower than in fruits, indicating a certain exclusion from seeds. Preliminary results of the PIXE technique showed that Al and Zn were distributed uniformly in the seeds (Cd was not detected with this technique), while the nutrients P and S were concentrated in the cotyledons.We thank JM Alegre for helping in the field work and Patricia Puente for helping in the lab work.We thank the National Accelerator Centre (CNA) of Seville for the analytical facilities. This study was supported by CGL2011-30285-C02 project, funded by the CICYT of the Spanish Ministerio de Ciencia e Innovación and European FEDER funds.Peer reviewe

Effects of temperature and nutrient supply on resource allocation, photosynthetic strategy, and metabolic rates of Synechococcus sp.

Temperature and nutrient supply are key factors that control phytoplankton ecophysiology, but their role is commonly investigated in isolation. Their combined effect on resource allocation, photosynthetic strategy, and metabolism remains poorly understood. To characterize the photosynthetic strategy and resource allocation under different conditions, we analyzed the responses of a marine cyanobacterium ( Synechococcus PCC 7002) to multiple combinations of temperature and nutrient supply. We measured the abundance of proteins involved in the dark (RuBis CO , rbc L) and light (Photosystem II , psbA) photosynthetic reactions, the content of chlorophyll a , carbon and nitrogen, and the rates of photosynthesis, respiration, and growth. We found that rbc L and psbA abundance increased with nutrient supply, whereas a temperature‐induced increase in psbA occurred only in nutrient‐replete treatments. Low temperature and abundant nutrients caused increased RuBis CO abundance, a pattern we observed also in natural phytoplankton assemblages across a wide latitudinal range. Photosynthesis and respiration increased with temperature only under nutrient‐sufficient conditions. These results suggest that nutrient supply exerts a stronger effect than temperature upon both photosynthetic protein abundance and metabolic rates in Synechococcus sp. and that the temperature effect on photosynthetic physiology and metabolism is nutrient dependent. The preferential resource allocation into the light instead of the dark reactions of photosynthesis as temperature rises is likely related to the different temperature dependence of dark‐reaction enzymatic rates versus photochemistry. These findings contribute to our understanding of the strategies for photosynthetic energy allocation in phytoplankton inhabiting contrasting environments.Agencia Estatal de Investigación | Ref. PGC2018‐094553‐B‐I00National Science Foundation (USA) | Ref. ANT‐0944254National Environmental Research Council (UK) | Ref. NE/F019254/1National Environmental Research Council (UK) | Ref. NE/G009155/1Xunta de Galici

Genetic drug target validation using Mendelian randomisation

Mendelian randomisation (MR) analysis is an important tool to elucidate the causal relevance of environmental and biological risk factors for disease. However, causal inference is undermined if genetic variants used to instrument a risk factor also influence alternative disease-pathways (horizontal pleiotropy). Here we report how the 'no horizontal pleiotropy assumption' is strengthened when proteins are the risk factors of interest. Proteins are typically the proximal effectors of biological processes encoded in the genome. Moreover, proteins are the targets of most medicines, so MR studies of drug targets are becoming a fundamental tool in drug development. To enable such studies, we introduce a mathematical framework that contrasts MR analysis of proteins with that of risk factors located more distally in the causal chain from gene to disease. We illustrate key model decisions and introduce an analytical framework for maximising power and evaluating the robustness of analyses

Los inceptisoles y entisoles del sector occidental de la Sierra de Gador (Almería)

Morphological and physicochemical properties of five Entisols and Inceptisols from west area of Sierra de Gádor are studied. "Soil Taxonomy" is the employed classification. Most soils are developed 'in situ' or upon colluvium derived from limestony and dolomitic marbles. 400 to 2.124 m. is the range of altitude. The slopes are variables. The vegetation is a degradated brushwood and reforestated pine woods. The moisture regime is Xeric; the temperature regime changes from Termi to Mesic at 1.000 m. The soils are tipic Xerorthents (three profils) and calcixerollic Xerochrepts (two profils). The analytical and morphological characteristics are variables owing to differencies in pedological evolution within the studied soils. But there are two characteristics in common: the high quantities of the alcalinoterreal bases controled by the parent material, and the absence of mollic epipedón owing to the degradation of climatic vegetation and parallel degradation or /and destruction of mineral organic soil horizons.En el presente estudio se analizan los caracteres morfológicos, las propiedades fisico-quírnicas y la clasificación a nivel de subgrupo de los suelos presentes en el Sector Occidental de la Sierra de Gádor, que pertenecen a los órdenes Entisol e Inceptisol de la taxonomía americana de suelos. Son suelos desarrollados sobre materiales calizo-dolomíticos "in situ" o coluvionados. La altitud oscila entre 400 y 2. 124 m. La pendiente es muy variable, desde llano o casi llano a fuertemente escarpado. Soportan un matorral degradativo y pinares de repoblación. El régimen de humedad es Xérico y el de temperatura Térmico hasta los 1.000 m. y Mésico por encima de esta cota. Los cinco perfiles muestreados se han clasificado como Xerorthent típicos y dos como Xerochrept calcixeróllicos. Los cinco perfiles muestreados se han clasificado, tres como Xerorthent típidiados, como respuesta a diferencias en evolución edáfica, exceptuando aquellos que dependen estrechamente del elevado contenido en bases alcalino térreas del material de origen. El carácter común más relevante es la carencia de epipedón móllico, provocada por la degradación del horizonte orgánicomineral al destruir la vegetación climácica

Caracterización de la capacidad agrológica de los suelos del sector noroeste de Sierra Nevada (Granada)

The soil map of the Northwest area of the Sierra Nevada it has been interpreted for agronomic purposes by the Spain Agricultural Ministry Scheme, called "Agrological Capacity characterization of the Soil of the Spain, Scale 1.50.000" . In this area the agrological capacity subclasses are: IVs, VIIw, VIs, VIc, Vle and VlIIe. The dominant classes are VII and VIII because the medium slopes are greater than 30 OJo. The subclasse Vle is frequent also (22-23 % of slope). Another subclasses and classes are in minor quantities. The slope and the mean anual temperature are the most important restraints. The surface stoniness, the surface rockiness and the soil moisture regime are important also. AH the results point out the suitability of this area for forestry, grassland and wildlife conservation.Se emplea el esquema del Ministerio de Agricultura Español denominado: "Caracterización de la Capacidad Agrológica de los Suelos de España a escala 1 :50.000", para interpretar desde un punto de vista agronómico la cartografía de suelos del Sector Noroeste de Sierra Nevada. Las subclases de capacidad agrológica presentes en el área son: IVs, VIw, VIs, Vlc, Vle, VIIe, VIIle. Las clases dominantes son la VII y la VIII, ya que las pendientes de casi toda el área superan el 30 OJo. Le sigue en abundancia la subclase Vle, localizada en las pendientes de la clase D (valor medio de 22 a 23%). El resto de las clases y subclases son minoritarias y aparecen de forma puntual. Las limitaciones de mayor importancia en el establecimiento de las clases de capacidad son en primer lugar, la pendiente y la temperatura y en segundo lugar la pedregosidad superficial, la rocosidad superficial y el exceso de humedad en el suelo. Estos resultados indican que los cultivos agrícolas (sólo posibles en los suelos de la clase IVs) se restringen a pequeñas zonas diseminadas por todo el área y que la mayor parte tiene vocación forestal, pastoral y de reserva natural

Coccolithophore calcification is independent of carbonate chemistry in the tropical ocean

Marañón, Emilio ... et al.-- 13 pages, 7 figures, 1 table, supporting information https://dx.doi.org/10.1002/lno.10295Short-term experiments indicate that seawater acidification can cause a decrease in the rate of calcification by coccolithophores, but the relationship between carbonate chemistry and coccolithophore calcification rate in natural assemblages is still unclear. During the Malaspina 2010 circumnavigation, we measured primary production, calcification, coccolithophore abundance, particulate inorganic carbon (PIC) concentration, and the parameters of the carbonate system, along basin-scale transects in the tropical Atlantic, Indian and Pacific oceans. Euphotic layer-integrated calcification and mean cell-specific calcification in the euphotic layer ranged between 2–10 mgC m−2 d−1 and 5–20 pgC cell−1 d−1, respectively. We found a significant relationship between primary production and calcification, such that the calcification to primary production (CP/PP) ratio was relatively invariant among ocean basins, with an overall mean value of 0.05 ± 0.04. Extrapolating this value to the entire ocean would result in a global pelagic calcification rate of 2.4 PtC yr−1. The mean PIC concentration in surface waters was 1.8 ± 1.6 mgC m−3 and its turnover time averaged 20 d. We combined our data of calcification, primary production, and carbonate chemistry from Malaspina 2010 with those obtained during two previous cruises in the northern Arabian Sea. Both the CP/PP ratio and cell-specific calcification were largely constant across a wide range of calcite saturation state (1.5–6.5), [ inline image]/[H+] (0.08–0.24; mol: μmol), and pH (7.6–8.1), which indicates that calcification by natural coccolithophore assemblages was independent of carbonate chemistry. Our results suggest that coccolithophore calcification, at least in tropical regions, may not be decreasing in the currently acidifying oceanFunding for this study was provided by the Spanish Ministry of Science and Innovation through research projects Malaspina 2010 (grant no. CSD2008-00077), PERSEO (CTM2007-28925-E/MAR), MANIFEST (CTM2012-32017) and TERRIFIC (CTM2014-53582-R). Funding for W.M.B. came from the NSF (OCE-0961660; OCE1220068), NASA (NNX11AO72G; NNX11AL93G; NNX14AQ41G; NNX14AQ43A; NNX14AL92G; NNX14AM77G) and NOAA (NA11OAR4310055).Peer Reviewe