Allelopathic potential of invasive Ulmus pumila on understory plant species

In Petriplate bioassay and Pot culture, we studied the allelopathic potential of leaf litter of Siberian elm (Ulmus pumila L.) invasive tree species on the germination and growth of three herbaceous plant native species (Dactylis glomerata L., Trifolium repens L. and Chenopodium album L.) commonly found in riparian understory communities. Two assays were done with leaf litter of U. pumila from riverine ecosystems (i). the effects of aqueous litter extracts in Petri dish assays and (ii). the effect of litter residues in pot experiments. The leaf litter extracts inhibited the radicle growth of D. glomerata and T. repens but did not effect the germination. However in pots, leaf litter inhibited the germination speed of C. album and growth of D. glomerata and T. repens. Our results showed the allelopathic potential of U. pumila litter, which reduced the growth of understory species (T. repens and D. glomerata). In the litter of U. pumila many phenolic compounds (hidroxibenzoic, ferulic, coumaric, protocatechuic, vanillic and rosmarinic acids, and quercetin) were detected.project POII10-0179-4700 of the Junta de Comunidades de Castilla La ManchaPeer reviewe

Fotografía y Guerra Civil española: del instante a la historia

Transcurridos 80 años del comienzo de la Guerra Civil española, el interés por este acontecimiento no ha cesado. Estudios de toda índole se han sucedido desde entonces, revelando la trascendencia de una contienda que condensó las claves políticas y sociales de su época. Estas circunstancias pusieron a prueba la capacidad de los medios de comunicación para dar cuenta de una guerra que, pese a iniciarse como un conflicto interno, muy pronto se internacionalizó

Demixing and orientational ordering in mixtures of rectangular particles

Using scaled-particle theory for binary mixtures of two-dimensional hard particles with rotational freedom, we analyse the stability of nematic phases and the demixing phase behaviour of a variety of mixtures, focussing on cases where at least one of the components consists of hard rectangles or hard squares. A pure fluid of hard rectangles may exhibit, aside from the usual uniaxial nematic phase, an additional (tetratic) oriented phase, possessing two directors, which is the analogue of the biaxial or cubatic phases in three- dimensional fluids. There is computer simulation evidence that the tetratic phase might be stable with respect to phases with spatial order for rectangles with low aspect ratios. As hard rectangles are mixed with other particles not possessing stable tetratic order by themselves, the tetratic phase is destabilised, via a first- or second-order phase transition, to uniaxial nematic or isotropic phases; for hard rectangles of low aspect ratio tetratic order persists in a relatively large range of volume fractions. The order of these transitions depends on the particle geometry, dimensions and thermodynamic conditions of the mixture. The second component of the mixture has been chosen to be hard discs or disco-rectangles, the geometry of which is different from that of rectangles, leading to packing frustration and demixing behaviour, or simply rectangles of different aspect ratio. These mixtures may be good candidates for observing thermodynamically stable tetratic phases in monolayers of hard particles. Finally, demixing between fluid (isotropic--tetratic or tetratic--tetratic) phases is seen to occur in mixtures of hard squares of different sizes when the size ratio is sufficiently large.Comment: 27 pages, 9 figure

Análisis del proceso de enseñanza-aprendizaje del ser vivo en un aula de primaria

El trabajo que presentamos se enmarca en un estudio más amplio sobre las dificultades y obstáculos del proceso de enseñanza-aprendizaje del concepto de ser vivo en un aula de primaria. Para ello se lleva a cabo la implementación de una unidad didáctica de corte investigativo, que es puesta en práctica por la propia investigadora, permaneciendo la maestra de la asignatura como observadora de todo el desarrollo. En este caso, se pretende llevar a cabo un análisis del proceso de enseñanza-aprendizaje del ser vivo partiendo de las ideas previas de los alumnos. Mediante el uso de varias herramientas de corte cualitativo, recogidos por los tres sectores que intervienen en la investigación, y mediante la triangulación de los datos obtenidos, se pretende analizar el cambio que se va produciendo en sus concepciones previas a medida que se van sucediendo las actividades propuestas

Changes in the Physicochemical and Nutritional Parameters of Picual and Arbequina Olive Oils during Frying

Deep fat frying is an important cooking process in Mediterranean countries. Olive oil is a very convenient fat to use for this culinary purpose. The chemical composition of olive oils differs from edible oils in terms of fatty acid and antioxidant compounds that gives olive oil its greater stability. The aim of this work was to describe the stability of Picual and Arbequina olive oil during deep frying of frozen potatoes in comparison with high oleic sunflower oil. Changes in different physicochemical and nutritional parameters were studied during frying. Picual olive oil had a higher stability in comparison with high oleic sunflower oil and Arbequina olive oil. Picual olive oil is very suitable for frying because it is able to undergo the greatest number of frying cycles without exceeding the limits allowed by regulations. This behavior is due to its phenolic content, the lower loss in tocopherol and better stability. Practical Applications: The information gained from this research could be very appropriate for consumers and for the industry to know which variety of olive oil is more suitable for frying longer frying cycles without exceeding the limits allowed by regulation and remain in good quality

Web based system architecture for long pulse remote experimentation

Remote experimentation (RE) methods will be essential in next generation fusion devices. Requirements for long pulse RE will be: on-line data visualization, on-line data acquisition processes monitoring and on-line data acquisition systems interactions (start, stop or set-up modifications). Note that these methods are not oriented to real-time control of fusion plant devices. INDRA Sistemas S.A., CIEMAT (Centro de Investigaciones Energéticas Medioambientales y Tecnológicas) and UPM (Universidad Politécnica de Madrid) have designed a specific software architecture for these purposes. The architecture can be supported on the BeansNet platform, whose integration with an application server provides an adequate solution to the requirements. BeansNet is a JINI based framework developed by INDRA, which makes easy the implementation of a remote experimentation model based on a Service Oriented Architecture. The new software architecture has been designed on the basis of the experience acquired in the development of an upgrade of the TJ-II remote experimentation system

Antifreeze proteins and homogeneous nucleation: On the physical determinants impeding ice crystal growth

Antifreeze proteins (AFPs) are biopolymers capable of interfering with ice growth. Their antifreeze action is commonly understood considering that the AFPs, by pinning the ice surface, force the crystal–liquid interface to bend forming an ice meniscus, causing an increase in the surface free energy and resulting in a decrease in the freezing point ΔT max. Here, we present an extensive computational study for a model protein adsorbed on a TIP4P/Ice crystal, computing ΔT max as a function of the average distance d between AFPs, with simulations spanning over 1 μs. First, we show that the lower the d, the larger the ΔT max. Then, we find that the water–ice–protein contact angle along the line ΔT max(d) is always larger than 0○ , and we provide a theoretical interpretation. We compute the curvature radius of the stable solid–liquid interface at a given supercooling ΔT ≤ ΔT max, connecting it with the critical ice nucleus at ΔT. Finally, we discuss the antifreeze capability of AFPs in terms of the protein–water and protein–ice interactions. Our findings establish a unified description of the AFPs in the contest of homogeneous ice nucleation, elucidating key aspects of the antifreeze mechanisms and paving the way for the design of novel ice-controlling materials