140 research outputs found

    Detailed analysis of the lamination and the geochemical varibility of the speleothem Zerolin to study the paleoclimate of SE Spain

    Get PDF
    This work reports an exhaustive analysis of geochemistry and lamination in the paleoclimate study of Málaga using an actively stalagmite called Zerolín, collected in 2007 in the Cave of Ardales. U-Th dates indicate that the speleothem began forming 1000 years ago. The older portion of the stalagmite presents a very marked lamination with an alternation of white and porous layers and denser dark layers. Lamination is absent in the younger portion of the stalagmite, which features darker calcite and slower growth rates. In the laminated part of the speleothem, a comparison of layer counting and U/Th dates indicates that light and dark couplets are annual. A detailed age model was then produced for the laminated part of the stalagmite based on layer counting anchored to a precise U/Th age. For the non-laminated portion of the stalagmite, U/Th dates were used in Bchron software to produce an age model. Periods of higher growth rate coincide with a greater thickness of white layers. In nonlaminated sections, U/Th dates confirm important depositional gaps. In the geochemical analysis it was discovered that the relationship and behavior of trace elements and stable isotopes is different in the upper zone than in the lower annually laminated zone. Over annual laminae cycles, trace elements such as Sr and d13C covary and may be driven by prior calcite precipitation, however Mg is out of phase with Sr. In nonlaminated segments, the correlations are not as systematic. The trace element and d13C indicate two periods of drier conditions in the stalagmite (1100-1200/1600-1800 AD) .These coincide with periods when there was an increase in the frequency of prayers for rainfall in historical documents from the Toledo Cathedral (F.Dominguez Castro et.al 2008), suggesting that the stalagmite is reflecting regionally significant humidity changes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Formación técnica por competencias laborales en la experiencia educativa de los CEFOP n°4 y n°10 del PASE (1996-2007).

    Get PDF
    En 1995 la Comisión Europea y el gobierno de Perú firmaron un convenio financiero. Así se creó el Programa de Apoyo al Ajuste Social Estructural (PASE) dirigido a jóvenes, de 15 a 29 años, que habían abandonado la educación secundaria y se encontraban en situación laboral inestable, en las regiones de La Libertad y Cajamarca. El Programa tuvo dos fases: 1995-2000 y 2001-2006. En el año 2001 Fe y Alegría, por convenio con el Ministerio de Educación, asumió la gestión de la segunda fase. El Programa PASE formó una red de 11 Centros de Formación Profesional (CEFOP) públicos, con gestión privada, y experimentó el modelo de formación técnica profesional basado en competencias laborales, según las exigencias del mercado laboral local. Así los jóvenes tendrían la oportunidad de acceder y conservar un puesto de trabajo en empresas y/o gestionar su propio empleo. Esto significó vincular la formación profesional de los jóvenes con el sector productivo. Según las evaluaciones del Ministerio de Educación, de la Comisión Europea y de Fe y Alegría (Oficina Central), el Programa ha sido una experiencia educativa exitosa. En la presente tesis presentamos la sistematización de las experiencias relevantes de los principales actores sobre aquellos elementos matrices de los CEFOP N°4 de Trujillo (planchado y pintura, cuero y calzado) y N°10 de Trujillo (comercio, alojamiento, cocina y restaurante, bar) que condujeron al éxito y el proceso matriz que articuló la formación profesional técnica ofrecida por estos CEFOP del PASE con el sector productivo local. Entre los principales factores que contribuyeron al éxito, destacamos: a) el diagnóstico socio económico en los lugares de la intervención, b) la coordinación del PASE, a través de los CEFOP N°4 y N°10, con diversos agentes sociales, económicos, educativos, etc., para diseñar y evaluar los perfiles profesionales y las competencias laborales; c) el uso de tecnología adecuada en los CEFOP N°4 y N°10, d) la gestión transparente y muy comprometida de los gestores del PASE y de los CEFOP N°4 y N°10, e) la formación integral (conocimientos, habilidades y actitudes). De este modo, el 68% de los egresados de estos CEFOP se encuentran trabajando en empresas y el 30% han generado su propio empleo. Por esta razón, creemos que la experiencia educativa de estos CEFOP podría replicarse en contextos afines.Tesi

    Análisis de la ciclicidad climática del baja frecuencia en los sedimentos lacustres del Grupo Enciso (Cretácico inferior de la Cuenca de Cameros, La Rioja): Aplicaciones a la correlación y dotación de la serie

    Get PDF
    En la localidad de Munilla, situada en el sector oriental de la Cuenca de Cameros, se ha levantado un perfil litológico de 996 m en los depósitos sinrift del Cretácico inferior, pertenecientes al Grupo Enciso. Se han caracterizado 7 facies ligadas a tres subambientes sedimentarios: fluvial, lago siliciclástico y lago carbonatado. En base a las facies diferenciadas el perfil se ha dividido en 74 ciclos. Las facies se han analizado mediante la metodología de las Cadenas de Markov lo que ha permitido identificar tres secuencias tipo, ligadas a los tres subambientes sedimentarios reconocidos. A partir de las relaciones entre facies se ha elaborado un modelo sedimentológico con la posición relativa de cada facies respecto a la línea de costa lacustre. La relación entre el espesor de los ciclos y su profundidad ponderada pone de manifiesto que, independientemente de tratarse de una cuenca activa con tectónica distensiva, son los factores climáticos los que controlan las variaciones en la profundidad del lago. Se ha realizado una serie de tiempo en base a rangos de profundidad que ha sido analizada con los programas REDFIT y Wavelet, lo que ha permitido identificar ciclos sedimentarios periódicos referibles a los ciclos de precesión, oblicuidad y excentricidad de las frecuencias de Milankovitch. El ciclo sedimentario periódico de 16,66 m es el que con mayor facilidad se identifica sobre el terreno y constituye la base del análisis secuencial. La tasa de sedimentación calculada para el Grupo Enciso es de 175 m/Ma y su sedimentación abarca un intervalo temporal de aproximadamente 6 Ma, extendiéndose desde el techo del Hauteriviense hasta la parte central del Aptiense

    Optimization of Verapamil Drug Analysis by Excitation-Emission Fluorescence in Combination with Second-order Multivariate Calibration

    Get PDF
    Abstract Excitation emission fluorescence matrices (EEMs) of Verapamil drug were obtained by direct and by derivatization fluorescence spectroscopy. The fluorescence excitation and emission wavelengths were displaced to longer wavelengths and the fluorescence intensity was enhanced upon derivation with respect to the native fluorescence of the drug. The complete EEM of the native fluorescence of the drug and of the derivatization product were rapidly acquired by using a charged-coupled device detector (CCD), which is advantageous in terms of speed in the analysis, with respect to the use of a conventional photomultiplier detector. The EEMs were analyzed by several second-order multivariate calibration methods exploiting the second order advantage. The three-dimensional decomposition methods used, based in different assumptions about the trilinearity of the three way data structure under analysis, were parallel factor analysis (PARAFAC), bilinear least squares (BLLS), parallel factor analysis 2 (PARAFAC2) and multivariate curve resolution—alternating least squares (MCR-ALS). The determination was performed by using the standard addition approach. The figures of merit of the PARAFAC and BLLS methods were calculated, obtaining a lower limit of detection with the derivatization procedure, when compared with the direct measurement of the fluorescence of the drug. In Verapamil drug the best estimations were found with the BLLS and the MCR-ALS models. In the quantification of Verapamil in a pharmaceutical formulation the best estimation, when compared with the result obtained by the US Pharmacopeia high performance liquid chromatography approach, was obtained by direct fluorescence spectroscopy with MCR-ALS and by derivatization fluorescence spectroscopy with the PARAFAC2 model

    Sedimentología y cicloestratigrafía de las calizas de plataforma abierta de la Fm. Río Palomar (Pliensbachiense inferior; cuenca Ibérica)

    Get PDF
    Las calizas de la Fm. Río Palomar (Pliensbachiense inferior) en el afloramiento de Almonacid de la Cuba (Zaragoza) se depositaron en una plataforma carbonatada de tipo rampa, entre los dominios medio-distal (facies dominante de wackestone bioclástico) y externo-proximal (facies mudstone, margocalizas y margas), donde la génesis y acumulación de sedimento se debió a producción bentónica y pelágica y a la resedimentación producida por las tormentas desde dominios someros. La sedimentación estuvo controlada por cambios climáticos relacionados con ciclos de Milankovitch. Estos habrían originado cambios periódicos de la acomodación-sedimentación, manifestados en secuencias sedimentarias de diferente orden (bundles, sets de bundles y lotes de sets), así como del aporte de detritos (minerales magnéticos), como refleja la ciclicidad obtenida del análisis espectral de los datos de susceptibilidad magnética (ciclos de excentricidad larga, oblicuidad y precesión). Los lotes de sets y los bundles corresponderían a los ciclos de excentricidad larga y precesión, respectivamente. Sin embargo, los ciclos de oblicuidad no tienen expresión estratigráfica en secuencias, ni los sets de bundles asignables a ciclos de excentricidad corta tienen su equivalente en el registro de la susceptibilidad magnética. Estas diferencias pueden relacionarse con la variable impronta de los cambios climáticos en el continente vs. la plataforma marina

    A Novel Root-Knot Nematode Resistance QTL on Chromosome Vu01 in Cowpea.

    Get PDF
    The root-knot nematode (RKN) species Meloidogyne incognita and M. javanica cause substantial root system damage and suppress yield of susceptible cowpea cultivars. The narrow-based genetic resistance conferred by the Rk gene, present in some commercial cultivars, is not effective against Rk-virulent populations found in several cowpea production areas. The dynamics of virulence within RKN populations require a broadening of the genetic base of resistance in elite cowpea cultivars. As part of this goal, F1 and F2 populations from the cross CB46-Null (susceptible) x FN-2-9-04 (resistant) were phenotyped for M. javanica induced root-galling (RG) and egg-mass production (EM) in controlled growth chamber and greenhouse infection assays. In addition, F[Formula: see text] families of the same cross were phenotyped for RG on field sites infested with Rk-avirulent M. incognita and M. javanica The response of F1 to RG and EM indicated that resistance to RKN in FN-2-9-04 is partially dominant, as supported by the degree of dominance in the F2 and F[Formula: see text] populations. Two QTL associated with both RG and EM resistance were detected on chromosomes Vu01 and Vu04. The QTL on Vu01 was most effective against aggressive M. javanica, whereas both QTL were effective against avirulent M. incognita Allelism tests with CB46 x FN-2-9-04 progeny indicated that these parents share the same RKN resistance locus on Vu04, but the strong, broad-based resistance in FN-2-9-04 is conferred by the additive effect of the novel resistance QTL on Vu01. This novel resistance in FN-2-9-04 is an important resource for broadening RKN resistance in elite cowpea cultivars

    Solar influence and hydrological variability during the Holocene from a speleothem annual record (Molinos Cave, NE Spain)

    Get PDF
    © 2015 John Wiley & Sons Ltd. We present a multi-proxy approach to reconstructing Holocene climate conditions in northeastern Spain based on an excellent correlation among the lamina thickness, colour parameters and isotope (δ18O and δ13C) variations recorded in a speleothem. An age model constructed from five U/Th dates and annual lamina counting suggests that the uppermost 14.7 cm of the MO-7 stalagmite grew between 7.2 and 2.5 ka before present but experienced a growth hiatus from 4.9 to 4.3 ka. Three spectral analysis methods were applied to 11 time series. The results reveal common solar periodicities on decennial (Gleissberg cycle) and centennial (De Vries-Suess cycle) scales. The onset of Holocene carbonate precipitation in the MO-7 stalagmite appears to be associated with a cold, wet period, whereas the hiatus and the end of growth are related to warm, dry periods. This environmental trend fits well within the regional Holocene climate.This study is a contribution to the CTM2013-48639-C2-1-R (OPERA), CGL2009–10455 and HIDROPAST (CGL2010-16376) projects (Spanish Government-European Regional Development Fund), the UZ2014-CIE-04 project (University of Zaragoza), the GA-LC-030/2011 project (Aragón Government-La Caixa) and the E–28 and S-97 research groups (Aragón Government).Peer Reviewe

    Efecto del escalamiento a 10 kg del catalizador Al/Fe-PILC sobre sus propiedades fisicoquímicas y catalíticas en la degradación de fenol

    Get PDF
    Durante la última década diferentes estudios han demostrado que las arcillas pilarizadas con el sistema mixto Al/Fe presentan una excelente respuesta catalítica en la degradación de compuestos orgánicos tóxicos disueltos en agua mediante Peroxidación Catalítica en Fase Húmeda (PCFH) [1-3]. Sin embargo,la implementación de ésta tecnología en la descontaminación de aguas a escala real depende fuertemente de la preparación reproducible del catalizador a mayor escala, sin una pérdida significativa de sus propiedades tanto fisicoquímicas como catalíticas. Este trabajo tiene como objetivo principal determinar el efecto de la preparación del catalizador Al/Fe-PILC en tres diferentes escalas y concentración de sus precursores

    Second-order calibration in combination with fluorescence fibre-optic data modelling as a novel approach for monitoring the maturation stage of plums

    Get PDF
    In this work, non-destructive autofluorescence of plums was employed to study the chlorophylls’ concentration evolution along the maturation process. For that, excitation-emission matrices (EEMs), containing full fluorescence information, were collected with a fibre-optic, assembled to a spectrofluorometer. Data analysis was performed with several second-order multi-way algorithms, such as parallel factor analysis (PARAFAC), multi-way partial least-squares (N-PLS), unfolded partial least-squares (U-PLS), and multivariate curve resolution-alternating least-squares (MCR-ALS). Firstly, the EEMs of each plum, collected each week along the maturation process, were processed with PARAFAC. Two components were used to model the data and the excitation and emission loadings were obtained. Score values for the first PARAFAC component showed a clear evolution with time, increasing during the first five weeks, and decreasing for the last weeks. Also, the chlorophyll concentrations obtained by HPLC analysis, in the skin and the whole fruit, were compared with those obtained with different algorithms mentioned before. Best results were obtained in the case of skin for all algorithms. Similar correlation coefficients (r) were obtained in all cases (0.899 (PARAFAC); 0.940 (U-PLS); 0.936 (N-PLS) and 0.958 (MCR-ALS)). When the elliptical joint confidence region (EJCR), for the slope and intercept, were calculated, the theoretically expected values of 1 and 0, for the slope and intercept, respectively, were included in all ellipses. However, it was observed that for the skin data and U-PLS and N-PLS algorithms, the EJCR confidence region was smaller than in the other cases.submittedVersio

    Late Pleistocene–Holocene palaeoenvironmental evolution of the Añamaza River valley (Iberian Range, NE Spain): Multidisciplinary approach on the study of carbonate fluvial systems

    Get PDF
    The uppermost Pleistocene and Holocene palaeoenvironmental evolution of the Añamaza river valley (Iberian Range, NE Spain) is deduced using multidisciplinary approach including stratigraphical, mineralogical, palynological, geochemical, geophysical methods and drilling. Main changes were registered in distinct subenvironments of a carbonate fluvial system, including the channelled zone and wetlands in the floodplain. Tufa barrages dominated although pools also existed. Geophysical survey and coring reveal tufa build-ups and pool facies also in the subsoil. Lower water temperature and scarce evaporation are deduced for the Pleistocene fluvial system that progressively changed through the Holocene, with more hydrologically closed areas and higher evaporation influence. A general aggrading evolution during warm stages related with increasing base level and damming due to fast carbonate precipitation, characterised the Holocene. Detrital tufa indicates erosive high-energy floods or colder stages when water level would decrease favouring erosion. 14C and 230Th/234U dating reveal high sedimentation rates and three main discontinuities related with cold episodes: Younger Dryas, middle part of the Holocene Climate Optimum and Iron Age Epoch. During the uppermost Pleistocene tufa growth would be enhanced during warmer episodes as the Bølling/Allerød. In the Younger Dryas scarce vegetation favoured erosion of both, slopes and tufa constructions. Subsequent warmer temperatures during the first part of the Holocene favoured vegetated slopes, enhanced tufa growing (although interrupted in the middle part of the Holocene Climate Optimum), and development of wetlands with riparian vegetation in the floodplain, where either siliciclastics or detrital tufa incoming alternated with low-energy waters stages and mud settling. Progressive decline in tufa is deduced for the upper Holocene but it is not possible to determine whether this, and other palaeoenvironmental changes were related either to climate or increasing human activities. During the Roman and Medieval Warm Periods more oxidizing conditions in the wetlands and increasing erosion prevailed, probably conditioned by human activities. The pollen record shows for the Early Holocene development of Pinus forest with Betula, and expansion of deciduous Quercus, xerophilous and heliophilous grassland. Subsequent increasing moisture supported open forests with deciduous (Quercus, Ulmus, Corylus) and evergreen (Quercus ilex, Pistacia) species. From ca.4000 yrBP, a dominant deciduous Quercus forest with groves of Corylus, Ulmus, Acer, Fagus and Taxus expanded and human activities (grazing) occurred. From 1200 yrBP dry grassland expanded due to intensive land use (agropastoral activities). Almost completely deforested plateaus surround the site today with slopes covered by patchy grass with junipers groves and screeds with little soil
    corecore