Mountain Pastures Structure and Its Relationship with Grazing

The present work aims toward an approach to mountain pastures as a system of relationships in which it is needed to point out those environmental factors that reflect more clearly their structure and potential productivity. This initial step of pasture tipification is important as a previous activity before the planning and management of protected areas because these areas support an intensive pastoral activity. In order to achieve this objective a field study was conducted in two areas in the Gorbeia Natural Park (Bizkaia): Arraba and Aldamiñape, located at 900-1100 masl. In each pasture four plots were selected according to orientation (north/south) and slope (\u3c 10%/\u3e 10%), and botanical composition and potential yield determined, as well as the pasture rejected by the livestock at three different times (June-August-November). Besides the herbage biomass yield data were related to grass height. It is observed that the topographical factors studied do not have a clear effect on potential yield at the different areas; however, there is a clear seasonality, being august the period with the highest herbage biomass production. Analyzing the data of herbage rejected by the livestock it is noted a differential livestock distribution on the pasture through the grazing time, being the area of Aldamiñape facing north and with \u3e 10% slope the area with the highest grazing pressure, which in turn is the area with a highest cover degree by Agrostis curtisii, an species of low nutritional value

The Use of Cover Crops After a Maize Crop in the North of Spain

This work intends to study N leaching losses in a field assay when crimson clover (Trifolium incarnatum) and italian ryegrass (Lolium multiflorum) was incorporated into the soil and quantify the their effect on N2O, N total gaseous losses under controlled soil moisture and temperature conditions. Field assay: A split-plot design where main plot was the cover crop and the subplot was the rate of fertilizer (0 and 150 kg N ha-1) applied to the subsequent maize crop. Laboratory assay: Residues of italian ryegrass and crimson clover were mixed with soil in containers, leaving one set of unamended controls. Incubations of soil during 27 days with a 0, 5 or 0.01 % C2H2 atmosphere allow us to obtain potential N2O and N total gaseous losses. In the field experiment crimson clover incorporation was better than ryegrass to resolve nitrate leaching losses due to 150 kg N ha-1 applied to maize although clover incorporation in the laboratory assay seemed to increase the risk of N2O emissions despite most gaseous losses were in the form of N2

Universal Vectorial and Ultrasensitive Nanomechanical Force Field Sensor

Miniaturization of force probes into nanomechanical oscillators enables ultrasensitive investigations of forces on dimensions smaller than their characteristic length scale. Meanwhile it also unravels the force field vectorial character and how its topology impacts the measurement. Here we expose an ultrasensitive method to image 2D vectorial force fields by optomechanically following the bidimensional Brownian motion of a singly clamped nanowire. This novel approach relies on angular and spectral tomography of its quasi frequency-degenerated transverse mechanical polarizations: immersing the nanoresonator in a vectorial force field does not only shift its eigenfrequencies but also rotate eigenmodes orientation as a nano-compass. This universal method is employed to map a tunable electrostatic force field whose spatial gradients can even take precedence over the intrinsic nanowire properties. Enabling vectorial force fields imaging with demonstrated sensitivities of attonewton variations over the nanoprobe Brownian trajectory will have strong impact on scientific exploration at the nanoscale

Fermi polaron-polaritons in charge-tunable atomically thin semiconductors

The dynamics of a mobile quantum impurity in a degenerate Fermi system is a fundamental problem in many-body physics. The interest in this field has been renewed due to recent ground-breaking experiments with ultracold Fermi gases. Optical creation of an exciton or a polariton in a two-dimensional electron system embedded in a microcavity constitutes a new frontier for this field due to an interplay between cavity coupling favouring ultralow-mass polariton formation6 and exciton–electron interactions leading to polaron or trion formation. Here, we present cavity spectroscopy of gate-tunable monolayer MoSe2 exhibiting strongly bound trion and polaron resonances, as well as non-perturbative coupling to a single microcavity mode. As the electron density is increased, the oscillator strength determined from the polariton splitting is gradually transferred from the higher-energy repulsive exciton-polaron resonance to the lower-energy attractive exciton-polaron state. Simultaneous observation of polariton formation in both attractive and repulsive branches indicates a new regime of polaron physics where the polariton impurity mass can be much smaller than that of the electrons. Our findings shed new light on optical response of semiconductors in the presence of free carriers by identifying the Fermi polaron nature of excitonic resonances and constitute a first step in investigation of a new class of degenerate Bose–Fermi mixtures.Physic

Multiparametric computer-aided differential diagnosis of Alzheimer's disease and frontotemporal dementia using structural and advanced MRI

textabstractObjectives: To investigate the added diagnostic value of arterial spin labelling (ASL) and diffusion tensor imaging (DTI) to structural MRI for computer-aided classificat

El sistema de innovación agroalimentario (AKIS) en el País Vasco

Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) y FEDER 2014-2020 "Programa Operativo de Crecimiento Inteligente", a través del proyecto CONNECTA RTA2015-00072-C03.Unpublishe

Estructura de los pastizales implantados en la zona del Gorbeia

La crisis del sector ganadero en los últimos años y la disminución de la carga ganadera en los pastizales de montaña provocó el abandono de estas áreas y la reinvasión de especies arbustivas. No obstante, hoy en día, ha aparecido una fuerte demanda por parte de los ganaderos para realizar transformaciones de áreas de matorral. Los pastizales objeto de este estudio, Altunoste y Arkaola, fueron implantados en los años 1984 y 1992 respectivamente, con laboreo y establecimiento de especies de interés forrajero (raigrás inglés, trébol blanco y dactilo). Entre los factores determinantes en la correcta implantación de un pastizal en suelos ácidos de monte están el encalado y la fertilización que se aplica. La metodología que se utiliza para estudiar el comportamiento de una especie con respecto a estos factores es la de los perfiles ecológicos. Entre los resultados obtenidos destacar que el factor pH es el principal responsable del mantenimiento de las especies sembradas, así como la plasticidad ecológica que presenta el dactilo frente al raigrás inglés y el trébol blanco más estrictos.Azken urteotan abeltzaintzak jasandako krisiak eta mendi-larreetako abere-zamaren gutxipenak area horien utziera sortarazi zuen eta honekin espezie zuhaixkaren birsatzea. Gaur egun berriz, abeltzainak sastraka-areak eraldatzeko eskari sendoa burutzen ari dira. Aztertutako zelaiak, Altunoste eta Arkaola, 1984 eta 1992. urtean ezarri ziren, hurrenez hurren. Horretarako lurra landu eta bazka bezala interesa duten espezie berriak erein ziren (erraigras ingelesa, hirusta zuria eta alka-belarra). Mendiko lur azidoetan larre baten ezarpen egokian karea eta ongarria botatzea faktore mugatzaileak dira. Faktore hauekiko espezieek duten portaera ikasteko erabiltzen den metodologia perfil ekologikoena da. Emaitzen arabera ereindako espezien mantenuan, pH-a da erantzule printzipala, eta baita alka-belarrak duen plastikotasun ekologikoa hertsiagoak diren erraigras ingelesa eta hirusta zuriaren aurrean.Dans les dernières années la cris de secteur d'élevage et la disminution de la charge éleveuse dans le pâturage de montagne ont provoquaient l'abondonement de ces terrains et la reinvasion des espèces arbustives. Cependant, actuellement, a apparu une forte demande des éleveurs pour réaliser des transformations des terrains de buisson. Les pâturages objet de cette étude, Altunoste et Arkaola, ont été plantés les années 1984 et 1992 respectivement, avec labourage et établissement des espèces d'interet fourregères (ray-gras anglais, trèfle blanc et le dactyle). Entre les facteurs déterminant la correcte implantation d'un pâturage dans les soles acides de montagne sont le badigeonnage et la fertilisation qui s'applique. La méthodologie qui s'utilise pour étudier le comportement d'une espèce en ce qui concerne ces facteurs c'est celle des perfiles écologiques. Entre les résultats obtenu vient le facteur pH c'est le principale responsable de subsistance des espèces cultivées, ainssi que la plasticité écologique qui représente le dactyle en face le ray-gras anglais et le trèfle blanc les plus stricts.The crisis that is undergoing the livestock sector and the decrease in the grazing pressure on mountain grasslands have lead to the abandonment of those areas and the reinvasion by shrubs. Nevertheless, nowadays there is an increasing demand of farmers to made transformations in the shruy areas: Arkaola and Altunoste. These meadows were sown in 1984 and 1992, respectively, with tillage and establishment of species of foraging interest (ryegrass, white clover and cocksfoot). Among the determinant factors for the correct establishment of the meadows on montain acid soils are liming and the fertilize rapplied. The methodology used to study the behaviour of the species according to those factors are Ecological Profiles. The results show that the pH is the main responsable for the maintenance of the sown species and that the cocksfoot has a higher ecological plasticity, than the ryegrass and white clover

ENSAYOS SUSTRACTIVOS DE FERTILIZACIÓN EN PRADOS DEL PAÍS VASCO. I. EFECTO DEL N, P, Y K SOBRE LA PRODUCCIÓN Y COMPOSICIÓN BOTÁNICA

El objetivo del presente trabajo fue cuantificar el efecto de los nutrientes N, P y K sobre la producción, composición botánica del prado y los contenidos de P y K del suelo. Para ello, se establecieron ensayos sustractivos de fertilización con los siguientes tratamientos: completo, sin N, sin P, sin K y control. El P fue el elemento más limitante (aumento de producción de hasta 6 veces) seguido del K en los suelos de baja fertilidad, mientras que si el P y K en suelo eran adecuados, el N limitaba la producción. El contenido de P del suelo aumentó mucho con la fertilización con P, pero los valores de K fueron más fluctuantes en función de las producciones anuales y de las extracciones de este elemento. Existió una relación entre los contenidos de P y K del suelo y la producción relativa, alcanzándose las máximas producciones para valores de 30-40 mg P/kg y 100-140 mg K/kg. En conclusión, cuando se conoce el efecto cuantitativo de la fertilización, ésta se puede manejar para alcanzar producciones adecuadas y controlar el equilibrio raigrás inglés/ trébol blanc