Ant Communities Resist Even in Small and Isolated Gypsum Habitat Remnants in a Mediterranean Agroecosystem

Natural and seminatural habitat remnants play a crucial ecological role in intensified agroecosystems. Assumptions on the conservation value of small and poorly connected fragments in a hostile matrix come from generalization obtained from a limited number of taxa, mostly plants, and vertebrates. To date, few studies have analyzed the effect of fragmentation on ant communities in Mediterranean agroecosystems, despite the importance of this group of animals on several key ecosystem functions and services. Here, we analyze the effects of fragment area and connectivity on ant communities in gypsum outcrops in a large cereal agroecosystem of Central Spain. Ant communities were described by their species composition, abundance (total number of occurrences), and number of species, standardized both by area (species density), and abundance (species richness). Observed number of species was relatively high in comparison with other studies in the Mediterranean, and we found no effects of fragment characteristics on species density, species richness and species composition, which implies that even small and isolated patches do have a value for ant conservation. Moreover, total number of occurrences were higher for smaller and more isolated fragments. This finding contrasts with the results reported for other taxa in similar gypsum habitats and suggests that certain ant traits and strategies make them particularly resistant to fragmentation and capable to take advantage of small habitat patches. Given the important ecological role played by ants, we recommend the preservation of these small habitat fragments in the management plans of agroecosystems in these drylands, especially in those cases in which intensification of agricultural practices greatly diminish natural habitat availabilit

Molecular dynamics simulations of nanosheets of polymeric carbon nitride and comparison with experimental observations

A computational study of the properties of polymeric carbon nitride using molecular dynamics is presented. The analysis of ideal infinite-extent sheets permits to evaluate the effect of temperature on the network of hydrogen bonds responsible for the linkage of the material. The weakening of this binding mechanism at sufficiently high temperatures, together with the inter-layer interactions characteristic of this type of 2D materials, is shown to determine the conformation properties of polymeric carbon nitride at the nanoscale. The results obtained from the simulation of finite samples in the canonical ensemble at varying temperatures are consistent with those from the characterization of our experimentally synthesized samples. Hydrogen bonding between adjacent polymer ribbons leads this process and is the cause of the typical crumpled structure of this material

Vibrational and thermal characterization of seeds, pulp, leaves and seed oil of Rosa rubiginosa

Rosa rubiginosa L. seed oil has been studied for its application in skin care products, but the chemical nature of seeds, pulp and even leaves, apart from that of oil, is also relevant with a view to the application of this weed for biodiesel production. All these vegetal materials were studied by infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) for characterisation purposes. FTIR bands at 3005, 2924, 1740, 1654 and 1456 cm-1 were used to estimate the iodine index, suitable for biofuels, and the oxidation stability degree. From the viewpoint of the thermal stability, both the seed oil (for which pyrolysis occurs at 462°C), the raw seeds and the rosehip pulp (with decomposition temperatures of 373°C and 333°C, respectively) showed potential as a biomass feedstock for conversion into biofuels. Caracterización térmica y vibracional de las semillas, pulpa, hojas y aceite de semillas de Rosa rubiginosa. El aceite de semillas de R. rubiginosa L. ha sido estudiado para su aplicación en productos para el cuidado de la piel, pero la naturaleza química de las semillas, pulpa y hojas, además de la del aceite, también es importante con miras a la aplicación de esta mala hierba para la producción de biodiesel. Los materiales vegetales mencionados se han estudiado mediante espectroscopía infrarroja (FTIR) y calorimetría diferencial de barrido (DSC) con fines de caracterización. Las bandas del espectro infrarrojo en 3005, 2924, 1740, 1654 y 1456 cm-1 han sido utilizadas para estimar el índice de yodo, adecuado para los biocombustibles, y el grado de estabilidad a la oxidación. Desde el punto de vista de la estabilidad térmica, tanto el aceite de semillas (para el que la pirólisis se produce a 462ºC) como las semillas crudas y la pulpa (con temperaturas de descomposición de 373°C y 333°C, respectivamente) mostraron potencial como materia prima de biomasa para su conversión en biocombustibles

Uncertainty quantification and predictability of wind speed over the Iberian Peninsula

During recent decades, the use of probabilistic forecasting methods has increased markedly. However, these predictions still need improvement in uncertainty quantification and predictability analysis. For this reason, the main aim of this paper is to develop tools for quantifying uncertainty and predictability of wind speed over the Iberian Peninsula. To achieve this goal, several spread indexes extracted from an ensemble prediction system are defined in this paper. Subsequently, these indexes were evaluated with the aim of selecting the most appropriate for the characterization of uncertainty associated to the forecasting. Selection is based on comparison of the average magnitude of ensemble spread (ES) and mean absolute percentage error (MAPE). MAPE is estimated by comparing the ensemble mean with wind speed values from different databases. Later, correlation between MAPE and ES was evaluated. Furthermore, probability distribution functions (PDFs) of spread indexes are analyzed to select the index with greater similarity to MAPE PDFs. Then, the spread index selected as optimal is used to carry out a spatiotemporal analysis of model uncertainty in wind forecasting. The results indicate that mountainous regions and the Mediterranean coast are characterized by strong uncertainty, and the spread increases more rapidly in areas affected by strong winds. Finally, a predictability index is proposed for obtaining a tool capable of providing information on whether the predictability is higher or lower than average. The applications developed may be useful in the forecasting of wind potential several days in advance, with substantial importance for estimating wind energy production

Geochemical study of products associated with spontaneous oxidation of coal in the Cerro Pelado Formation, Venezuela

The aim of this research work is a geochemical, mineralogical, and textural characterization of spontaneously smouldered coal-derived products in northwestern Venezuela (Cerro Pelado Formation, some 10 km from Pedregal city). Several solid samples were collected from this formation, six of unweathering coal, an other six of resulting unmelted rocks forming on a surface coal bed, and the last four of mineralizations found accumulating around gas vents. The fresh coal and the unmelted material were analysed by scanning electron microscopy, X-ray diffraction, and proximate techniques. Products such as magnetite and chabazite-K were identified in the alteration rocks. Likewise, both materials were also studied in order to determine the mobilization of 17 elements into the environment; such elements were analysed through inductively coupled plasma atomic emission spectroscopy on extracts obtained by a sequential extraction method: each sample was firstly extracted with MilliQ water and then the resultant residue was washed. This and the subsequently resulting residues are extracted according to the mentioned procedure by using, respectively, ammonium acetate, chlorhydric acid, peroxide and chlorhydric acid, nitric acid and fluorhydric acid, and nitric acid. The studied elements are classified as highly mobile (Na, Ni, ...), nearly immobile (Ti, P) and partially mobile (Mg, Fe, K,...). In regards to mineralizations around fumaroles associated with smoldering coal seams, Fourier-transform infrared spectroscopy and X-ray diffraction analyses have revealed the presence of salammoniac, mascagnite and other solid combustion compounds formed by reaction of gas emitted from coal oxidation, in addition to previously non-reported sulfur-rich by-products associated with gas fissures, particularly ammonium thiosulfate, a phase first obtained only synthetically in the laboratory. Another objective of the research was to collect and analyse gases escaping from surficial vents. Relatively high concentrations of several aromatic compounds were detected in the gas collected at the studied coal outcrop, as well as aliphatic hydrocarbons including ethane, propane, butanes, among others. High contents of carbon monoxide, methane and carbon dioxide were also measured for gas samples

Biodiversidad de los LIC Banco de La Concepción y Espacil marino del oriente y sur de Lanzarote-Fuerteventura. Especies protegidas y formadoras de hábitats

Two large areas belonging to the Canary Islands marine demarcation are part of the Natura 2000 network as Sites of Community Importance (SCI): “ESZZ15001-Banco de la Concepción” (total area 609,721.92 ha; depth range 158-2,687 m) and “ESZZ15002-Espacio marino del oriente y sur de Lanzarote y Fuerteventura” (total area 1,433,248.92 ha; depth range 0-3,300 m). Within the framework of the LIFE INTEMARES IP project, Action A.2.1, and before the designation of these two SCIs as Special Areas of Conservation, the Spanish Institute of Oceanography (IEO) is responsible for completing information necessary for the development of management plans. In the present study, a general analysis of the biodiversity of the two SCIs is carried out, starting from the updated catalogs, based mainly on previous IEO research and on information from the Canary Islands Biodiversity Data Bank, a comprehensive database of the Regional Government that draws on all current and historical information, backed by documents supervised by specialists. Special emphasis is placed on protected species and habitat forming species, which are considered key elements for management.Dos grandes zonas de la demarcación marina de las islas Canarias forman parte de la Red Natura 2000 como Lugares de Importancia Comunitaria (LIC): “ESZZ15001-Banco de la Concepción” (área total 609.721,92 ha; rango de profundidad 158-2.687 m) y “ESZZ15002-Espacio marino del oriente y sur de Lanzarote y Fuerteventura” (área total 1.433.248,92 ha; rango de profundidad 0-3.300 m). El Instituto Español de Oceanografía (IEO) ha sido encargado de completar la información necesaria para el desarrollo de los planes de gestión, como paso previo a la declaración de estos LIC como Zonas de Especial Conservación, en el marco del proyecto LIFE IP INTEMARES, Acción A.2.1. En el presente trabajo se realiza un análisis general de la biodiversidad de los dos LIC, partiendo de los catálogos actualizados, basados principalmente en investigaciones previas del IEO y en la información del Banco de Datos de Biodiversidad de Canarias, una completa base de datos que recopila toda la información actual e histórica, respaldada por documentos supervisados por especialistas. Se presta una especial atención a las especies protegidas y a las formadoras de hábitats, que son consideradas elementos claves para la gestiónTwo large areas belonging to the Canary Islands marine demarcation are part of the Natura 2000 network as Sites of Community Importance (SCI): “ESZZ15001-Banco de la Concepción” (total area 609,721.92 ha; depth range 158-2,687 m) and “ESZZ15002-Espacio marino del oriente y sur de Lanzarote y Fuerteventura” (total area 1,433,248.92 ha; depth range 0-3,300 m). Within the framework of the LIFE INTEMARES IP project, Action A.2.1, and before the designation of these two SCIs as Special Areas of Conservation, the Spanish Institute of Oceanography (IEO) is responsible for completing information necessary for the development of management plans. In the present study, a general analysis of the biodiversity of the two SCIs is carried out, starting from the updated catalogs, based mainly on previous IEO research and on information from the Canary Islands Biodiversity Data Bank, a comprehensive database of the Regional Government that draws on all current and historical information, backed by documents supervised by specialists. Special emphasis is placed on protected species and habitat forming species, which are considered key elements for management.En prens

Selective expression of the neurexin substrate for presenilin in the adult forebrain causes deficits in associative memory and presynaptic plasticity

Presenilins (PS) form the active subunit of the gamma-secretase complex, which mediates the proteolytic clearance of a broad variety of type-I plasma membrane proteins. Loss-of-function mutations in PSEN1/2 genes are the leading cause of familial Alzheimer's disease (fAD). However, the PS/gamma-secretase substrates relevant for the neuronal deficits associated with a loss of PS function are not completely known. The members of the neurexin (Nrxn) family of presynaptic plasma membrane proteins are candidates to mediate aspects of the synaptic and memory deficits associated with a loss of PS function. Previous work has shown that fAD-linked PS mutants or inactivation of PS by genetic and pharmacological approaches failed to clear Nrxn C-terminal frag-ments (NrxnCTF), leading to its abnormal accumulation at presynaptic terminals. Here, we generated transgenic mice that selectively recreate the presynaptic accumulation of NrxnCTF in adult forebrain neurons, leaving unaltered the function of PS/gamma-secretase complex towards other substrates. Behavioral characterization identified selective impairments in NrxnCTF mice, including decreased fear-conditioning memory. Electro-physiological recordings in medial prefrontal cortex-basolateral amygdala (mPFC-BLA) of behaving mice showed normal synaptic transmission and uncovered specific defects in synaptic facilitation. These data functionally link the accumulation of NrxnCTF with defects in associative memory and short-term synaptic plasticity, pointing at impaired clearance of NrxnCTF as a new mediator in ADMinisterio de Ciencia, Innovación y Universidades (RTI2018-101886-B-100)Junta de Andalucía (PY18-823)Junta de Andalucía (P11- CVI-7599)Ministerio de Economía, Industria y Competitividad (BES-2016-076579)Garantía Juvenil contract from Universidad de Sevill

Effects of Fe3+ substitution on Zn-Al layered double hydroxides for enhanced NO photochemical abatement

In this work the ability of ZnAlFe-CO3 layered double hydroxides (LDHs) as highly efficient UV-Vis light photocatalysts for the photochemical oxidation of NO gas was studied. LDHs with 3.5 to 4.1 M2+/M3+ and 0.33 to 1.55 Fe/Al ratios were prepared by a coprecipitation method. The samples were characterized by different techniques such as XRD, XPS, FT-IR, ICP-MS, TG, SBET, SEM and Diffuse reflectance (DR). The increased presence of the Fe3+ ions gave rise to changes in the structure, morphology and optical properties of the LDHs. The prepared ZnAlFe-CO3 systems exhibited increased surface area and enhanced visible-light absorbance. The photochemical NO abatement resulted in outstanding conversion efficiency (56 %) and selectivity (93 %) for the iron containing samples, due to a decrease of the e-/h+ recombination, higher generation of ⋅O2- and ⋅OH radicals and their NO2 adsorption ability

Use of Natural Microtalcs during the Virgin Olive Oil Production Process to Increase Its Content in Antioxidant Compounds

During the olive oil production process, certain olive varieties, such as ‘Hojiblanca’ and ‘Picual’, create pastes from which it is difficult to separate the oil, resulting in low extraction yields. To improve oil extraction, one alternative is the addition of natural microtalcs (NMT). In the present study, a NMT of great purity (CaCO3 concentration less than 6 wt.%) and small average particle size (φ ≤ 2.1 µm) was added in the malaxation stage on an industrial scale at two olive mills. In one of them and using ‘Hojiblanca’ olives, the performance of the high-purity NMT was compared with that of a traditional NMT, while in the other, the effect of its dosage in the quality of ‘Picual’ oils was assessed. The performance of the high-purity NMT was evaluated in terms of industrial oil yield, extractability index, quality parameters and oxidative stability of the resulting oils. The addition of the high-purity NMT not only increased the extraction yields but also improved the quality of the virgin olive oils, especially in relation to antioxidant compounds (tocopherols and phenolic compounds). Increases of 10.4% in phenolic compounds and of 21.5% in the tocopherols were found, thus enhancing the oxidative stability of the oils