Gibbs-Donnan and specific ion interaction theory descriptions of the effect of ionic strength on proton dissociation of alginic acid

The apparent proton dissociation constants of a commercial alginic acid have been obtained in KNO3 and NaCl at concentrations ranging between 0.01 and 2 mol·L-1. An analysis of the dependence on the ionic strength at a constant value of the dissociation degree was done by means of empirical functions derived from the Gibbs-Donnan formalism for polyelectrolytes and a specific ion interaction theory (SIT). Both functions were able to fit the experimental data, although SIT yielded rather high errors in the fitted parameters due to a problem of multicollinearity, in contrast to the function derived from the Gibbs-Donnan approach.This work was funded by the projects BQU2002-02133 (from the Ministerio de Ciencia y Tecnología of Spain) and PGDIT02TAM10302PR (from the Xunta de Galicia). C.R.C. benefited from a FPU grant of the Ministerio de Educación, Cultura y Deporte of Spain

Removal of Inorganic Mercury From Aqueous Solutions by Biomass of the Marine Macroalga Cystoseira Baccata

[Abstract] The ability of Cystoseira baccata algal biomass to remove Hg(II) from aqueous solutions is investigated. The mercury biosorption process is studied through batch experiments at 25ºC with regard to the influence of contact time, initial mercury concentration, solution pH, salinity and presence of several divalent cations. The acid-base properties of the alga are also studied, since they are related to the affinity for heavy metals. The studies of the pH effect on the metal uptake evidence a sharp increasing sorption up to a pH value around 7.0, which can be ascribed to changes both in the inorganic Hg(II) speciation and in the dissociation state of the acid algal sites. The sorption isotherms at constant pH show uptake values as high as 178 mg.g-1 (at pH 4.5) and 329 mg.g-1 (at pH 6.0). The studies of the salinity influence on the Hg(II) sorption capacity of the alga exhibit two opposite effects depending on the electrolyte added; an increase in concentration of nitrate salts (NaNO3, KNO3) slightly enhances the metal uptake, on the contrary, the addition of NaCl salt leads to a drop in the sorption. The addition of different divalent cations to the mercury solution, namely Ca2+, Mg2+, Zn2+, Cd2+, Pb2+ and Cu2+, reveals that their effect on the uptake process is negligible. Finally, the equilibrium sorption results are compared with predictions 1 obtained from the application of a simple competitive chemical model, which involves a discrete proton binding constant and three additional constants for the binding of main neutral inorganic Hg(II) complexes, Hg(Cl) HgOHCl and Hg(OH)2, to the algal surface sites

Título: Carta Real 1696 02 13

Port. con esc. xil. real y de la Sede Valentin

Título: Cédula Real 1798 06 19

Certifica la copia Vicente EsteveCédula dada en Aranjuez, a 19 de junio de 1798Sign.: [ ]6Port. con esc. real xil.Apostillas marginale

Firm and industry effects on small, medium-sized and large firms’ performance

This paper examines whether or not the relative importance of the firm and industry effects in explaining performance variations is the same regardless of the firm size. In relation to size, we think that there has been particular neglect of studying medium-sized firms separately from SMEs in general. That is why we study separately large, medium-sized and small firms. We also contribute to knowledge on the firm-industry debate testing empirically both effects distinguishing the firms by size according to a standard classification in the EU. Our results show that the performances of large and small firms are mainly explained by the firm effect, albeit for different reasons, while the performance of medium-sized firms is explained primarily by the industry effect

Agricultural extensification enhances functional diversity but not phylogenetic diversity in Mediterranean olive groves: A case study with ant and bird communities

Agroforests are of well-known importance for biodiversity conservation, especially in the tropics, because they are structurally stable and may resemble natural forests. Previous studies have characterized jointly taxonomic, functional and phylogenetic diversity in these agro-ecosystems to comprehensively examine the mechanisms by which agriculture impacts on biodiversity. However, this approach has been barely applied to other woody crops of economic importance, such as olive grove, which is a remarkable overwintering habitat for frugivorous/insectivorous birds from central and northern Europe, and whose original distribution overlaps with the Mediterranean biodiversity hotspot. We examined the effects of landscape complexity and intensive management practices at a local scale (recurrent plowing and pesticides use) on the functional and phylogenetic diversity of animal communities inhabiting olive groves. Since the response of functional traits or clades may vary across different taxonomic groups, we conducted our study at two levels: ants, which are considered semi-sessile organisms, and birds, which exhibit a high dispersal capacity. In birds, neither management type nor landscape complexity had an effect on phylogenetic diversity (PD) indices. Extensively managed farms harbored bird communities with higher values of functional diversity (FD), but this effect only was evident when considering cultivated (productive) zones within the farm (i.e., infield diversity). Ant assemblages on intensively managed farms exhibited a lower level of phylogenetic clustering than those located in extensive farms, but this effect vanished when excluding non-cultivated zones. Ant functional diversity increased with landscape complexity. Our results indicate that PD and FD exhibit different responses to farming intensification in olive groves. Although intensive management does not erode PD due to the existence of phylogenetic redundancy, the loss of species associated to modern farming leads to a reduction in FD being this indicative of functional complementarity. This study provides evidence that land-use extensification (extensive farming and landscape diversification) promotes more functionally rich assemblages than modern intensive practices in olive groves. Our findings also show the need to set apart the effect of non-cultivated zones (e.g., hedgerows, margins) when evaluating the effectiveness of agri-environment schemes as the joint consideration of non-cultivated and cultivated areas may obscure the benefits of local extensification on infield biodiversity.info:eu-repo/semantics/publishedVersio

XF-ROVIM, un robot para la detección de enfermedades en campo mediante teledetección. Aplicación a la detección de Xylella fastidiosa

Se ha desarrollado un robot flexible y económico, fácil de transportar y capaz de embarcar equipos de teledetección, con el objetivo de inspeccionar cultivos arbóreos en el marco del proyecto H2020 XF-ACTORS, financiado por la UE (#727987). El robot XF-ROVIM se maneja por control remoto y se impulsa gracias a dos motores eléctricos. Permite equipar dos cámaras réflex (una modificada para imágenes BNDVI), una cámara multiespectral (ocho bandas entre 550 y 850 nm), una cámara hiperespectral de barrido (rango 400 - 1000 nm) y una cámara térmica. Además, se ha montado un escáner LiDAR 2D para obtener características estructurales tridimensionales de los árboles, un receptor GNSS para geolocalizar las imágenes y datos obtenidos, y una unidad de medida inercial (IMU) para corregir los datos capturados por el LiDAR influenciados por las irregularidades del terreno.Se ha utilizado para detectar olivos infectados por Xylella fastidiosa mediante teledetección en una parcela potencialmente afectada en la región de Lecce (sur de Italia). El robot recorrió el cultivo monitorizando las cuatro caras de cada árbol (más de 400 árboles) con cámaras (más de 35000 imágenes) y la información LiDAR. Los datos ya analizados se pueden visualizar sobreimpresos en el mismo campo utilizando la aplicación Google Earth®.El robot XF-ROVIM (Xylella fastidiosa - Remotely Operated Vehicle for Infection Monitoring in orchards), se ha desarrollado en el marco del proyecto H2020 XF-ACTORS, financiado por la UE (#727987) para detectar olivos infectados por X. fastidiosa mediante teledetección. El sistema desarrollado se ha probado en un campo de olivos potencialmente infectados por X. fastidiosa en la región de Lecce (sur de Italia). El robot avanzó en cada fila recogiendo primero los datos de los árboles de un lado y luego de los árboles del otro lado de la misma fila en su camino de regreso. Posteriormente, se inspeccionaron las filas perpendiculares obteniendo datos de las cuatro caras del árbol. El robot funcionó correctamente durante las pruebas preliminares, capturando aproximadamente 35000 imágenes con todas las cámaras (aproximadamente una imagen por metro de avance), y la información LiDAR que se usó para reconstruir en 3D los árboles y obtener información sobre su estructura. Las imágenes obtenidas están aún bajo análisis. Sin embargo, los datos ya analizados, que se pueden visualizar sobreimpresos en el mismo campo utilizando la aplicación Google Earth® demuestran la idoneidad de este tipo de plataformas para la inspección de enfermedades u otras características vegetativas importantes en el campo

Recognition memory deficits in mild cognitive impairment

There is no agreement on the pattern of recognition memory deficits characteristic of patients diagnosed with mild cognitive impairment (Mel). Whereas lower performance in recollection is the hallmark of Mel, there is a strong controversy about possible deficits in familiarity estimates when using recognition memory tasks. The aim of this research is to shed Iight on the pattern of responding in recollection and familiarity in MCl. Five groups of participants were tested. The main participant samples were those formed by two Mel groups differing in age and an Alzheimer's disease group (AD), which were compared with two control groups, Whereas one of the control groups served to assess the performance of the MeI and AD people, the other one, composed of young healthy participants, served the purpose of evaluating the adequacy of the experimental tasks used in the evaluation of the different components of recognition memory. We used an associative recognition task as a direct index of recollection and a choice task on a pair of stimuli, one of which was perceptually similar to those studied in the associative recognition phase, as an index of familiarity. Our results indicate that recollection decreases with age and neurological status, and familiarity remains stable in the elderly control sample but it is deficient in Me!. This research shows that a unique encoding situation generated deficits in recollective and familiarity mechanisms in mild cognitive impaired individuals, providing evidence for the existence of deficits in both retrieval processes in recognition memory in a MeI stage

La Real Academia de San Carlos, que debió al señor D. Fernando VII ... los ... favores de que la honrara con su presencia ... y habiendose verificado su ... matrimonio con ... Doña Maria Isabel de Portugal, determino batir una medalla de ... un peso fuerte ... ha trabajado esta obra D. Manuel Peleguer director de Grabado de la Academia ...

Tít. tomado de principio de textoFecha tomada de final de texto: "Por acuerdo de la Real Academia de las Nobles Artes de Valencia. Año de 1816"Sign.: []2Grab. calc. del anverso y reverso de la moneda en cabecera: "Capilla