Stress-assisted atomic diffusion in metastable austenite D03 phase of Cu-Al-Be shape memory alloys

AbstractCu-Al-based shape memory alloys are firm candidates to be used up to 473K. The main limiting aspect is the activation of diffusion processes in the metastable austenite phase, which drive the alloy decomposition. In the present work the study of short-distance diffusion processes has been approached by internal friction. A relaxation peak has been found in the metastable β (D03) phase of a Cu-Al-Be shape memory alloy, around 500K (at 1Hz), with an activation energy of Ea=1.38±0.05eV. An atomic mechanism of elastic dipoles Antisite-Vacancy reorientation, involving stress-assisted short distance Cu-atoms diffusion, has been proposed

Real time plasma disruptions detection in JET implemented with the ITMS platform using FPGA based IDAQ

The use of FPGAs in data acquisition cards for processing purposes allows an efficient real time pattern recognition algorithm implementation. Using 13 JETs database waveforms an algorithm for detecting incoming plasma disruptions has been implemented. This algorithm is written in MATLAB using floating point representation. In this work we show the methodology used to implement the real time version of the algorithm using Intelligent Data Acquisition Cards (IDAQ), DAQ devices with field programmable gate array (FPGA) for local processing. This methodology is based on the translation of the MATLAB code to LabVIEW and the final coding of specific pieces of code in LabVIEW for FPGA in fixed point format. The whole system for evaluating the real time disruption detection (RTDD) has been implemented using the Intelligent Test and Measurement System (ITMS) platform. ITMS offers distributed data acquisition, distribution and real time processing capabilities with advanced, but easy to use, software tools that simplify application development and system setup. The RTDD implementation uses a standard PXI/PXIe architecture. Two 8 channel analog output cards play JETs database signals, two 8 channel DAQ with FPGA acquire signals and computes a feature vector based in FFT analysis. Finally the vector acquired is used by the system CPU to execute a pattern recognition algorithm to estimate an incoming disruption

Implications of seed policies for on-farm agro-biodiversity in Ethiopia and Uganda

Across East Africa, national seed policies and commercial seed enterprises have focused on increasing farmers’ access to modern seed varieties. These new varieties are developed and delivered to farmers via the formal seed system, which is comprised of government and private sector seed breeders, processors, and vendors. However, the formal seed system only provides a small share (<20%) of smallholders’ seed in the region. Most farmers source seed from informal seed systems, including own-saved seed, exchanges with neighbors, and local seed markets. At the local level, informal seed systems are preferred by farmers because of proximity and local varietal preferences (e.g., crop variety tastes and suitability for local environmental conditions). At the national and regional levels, the conservation and use of local crop varieties through informal systems has also provided a wealth of crop genetic diversity increasingly recognized as critical for climate change adaptation. To evaluate how policies in East Africa impact seed systems we systematically code 117 provisions in 21 national seed policies in Ethiopia (n=11) and Uganda (n=10), highlighting the implications of current and proposed policies for the availability and accessibility of: (i) improved seed; (ii) quality-controlled seed; and (iii) genetically diverse local seed in both the formal and informal seed systems in each country

Additive noise effects in active nonlinear spatially extended systems

We examine the effects of pure additive noise on spatially extended systems with quadratic nonlinearities. We develop a general multiscale theory for such systems and apply it to the Kuramoto-Sivashinsky equation as a case study. We first focus on a regime close to the instability onset (primary bifurcation), where the system can be described by a single dominant mode. We show analytically that the resulting noise in the equation describing the amplitude of the dominant mode largely depends on the nature of the stochastic forcing. For a highly degenerate noise, in the sense that it is acting on the first stable mode only, the amplitude equation is dominated by a pure multiplicative noise, which in turn induces the dominant mode to undergo several critical state transitions and complex phenomena, including intermittency and stabilisation, as the noise strength is increased. The intermittent behaviour is characterised by a power-law probability density and the corresponding critical exponent is calculated rigorously by making use of the first-passage properties of the amplitude equation. On the other hand, when the noise is acting on the whole subspace of stable modes, the multiplicative noise is corrected by an additive-like term, with the eventual loss of any stabilised state. We also show that the stochastic forcing has no effect on the dominant mode dynamics when it is acting on the second stable mode. Finally, in a regime which is relatively far from the instability onset, so that there are two unstable modes, we observe numerically that when the noise is acting on the first stable mode, both dominant modes show noise-induced complex phenomena similar to the single-mode case

Community structure of pelagic copepods in the eastern tropical Pacific Ocean during summer and autumn.

The Eastern Tropical Pacific Ocean (ETPO) is a region of interest for commercial fisheries but is subject to high oceanographic variability, which affects primary and secondary production. Because pelagic copepods contribute significantly to secondary productivity, they were investigated to examine community structure variation both temporally and spatially. Zooplankton samples were collected from August to December 2003 using a bongo net (333 µm in mesh size). Ninety-six zooplankton samples were analysed, recording 94 copepod species from orders Calanoida, Cyclopoida, Harpacticoida and Poecilostomatoida. The study area could be divided into six geographical zones based on the numerically dominant species. The oceanographic conditions were relatively stable during summer and autumn. Total copepod abundance was higher (47,096 to 62,681 ind.100 m-3) in stations near the coast, mostly in southern Baja California and the Gulf of Tehuantepec; the lowest densities were recorded towards the study area's oceanic regions. Similarly, ecological diversity was higher in zones influenced by tropical mass waters. The biogeographical affinity of copepod species was dominated by tropical species (75.5%), whereas subtropical and temperate species were far less abundant (15.7 and 8.6%, respectively).Versión del editor0,708

Cholesterol content regulates acrosomal exocytosis by enhancing Rab3A plasma membrane association

AbstractThe acrosome is an exocytic granule that overlies the spermatozoan nucleus. In response to different stimuli, it undergoes calcium-regulated exocytosis. Freshly ejaculated mammalian sperm are not immediately capable of undergoing acrosome reaction. The acquisition of this ability is called capacitation and involves a series of still not well-characterized changes in the sperm physiology. Plasma membrane cholesterol removal is one of the sperm modifications that are associated with capacitation. However, how sterols affect acrosomal exocytosis is unknown. Here, we show that short incubations with cyclodextrin, a cholesterol removal agent, just before stimulation promote acrosomal exocytosis. Moreover, the effect was also observed in permeabilized cells stimulated with calcium, indicating that cholesterol plays a direct role in the calcium-dependent exocytosis associated with acrosome reaction. Using a photo-inhibitable calcium chelator, we show that cholesterol affects an early event of the exocytic cascade rather than the lipid bilayers mixing. Functional data indicate that one target for the cholesterol effect is Rab3A. The sterol content does not affect the Rab3A activation–deactivation cycle but regulates its membrane anchoring. Western blot analysis and immunoelectron microscopy confirmed that cholesterol efflux facilitates Rab3A association to sperm plasma membrane. Our data indicate that the cholesterol efflux occurring during capacitation optimizes the conditions for the productive assembly of the fusion machinery required for acrosome reaction

Implementation of PEF treatment at real-scale tomatoes processing considering LCA methodology as an innovation strategy in the agri-food sector

In Europe, science and innovation are boosting the agri-food sector and, in parallel, are helping to decrease greenhouse gas emissions (GHG) and European dependency on non-renewable resources. Currently, it is well-known that this sector contributes to the consumption of energy and material resources, causing significant environmental impacts that require a complex and comprehensive environmental evaluation in order to manage them effectively. This becomes even more complicated when new technologies are reaching the level of technological maturity needed to be installed in the production lines. To address this scientific challenge, the life cycle assessment (LCA) has been used in this paper to evaluate the potential of pulsed electric fields (PEF) technology at an industrial scale to facilitate the steam peeling of tomato fruits. Considering the thermo-physical peeling stage, the LCA has shown that PEF technology is environmentally friendly, because when PEF technology is applied, all the considered environmental indicators improve between 17% and 20%

Structure of ternary additive hard-sphere fluid mixtures

Monte Carlo simulations on the structural properties of ternary fluid mixtures of additive hard spheres are reported. The results are compared with those obtained from a recent analytical approximation [S. B. Yuste, A. Santos, and M. Lopez de Haro, J. Chem. Phys. 108, 3683 (1998)] to the radial distribution functions of hard-sphere mixtures and with the results derived from the solution of the Ornstein-Zernike integral equation with both the Martynov-Sarkisov and the Percus-Yevick closures. Very good agreement between the results of the first two approaches and simulation is observed, with a noticeable improvement over the Percus-Yevick predictions especially near contact.Comment: 11 pages, including 8 figures; A minor change; accepted for publication in PR

Cytotoxic, antioxidant, and enzyme inhibitory properties of the traditional medicinal plant matthiola incana (L.) R. Br.

Matthiola incana (L.) R. Br. (Brassicaceae) is widely cultivated for ornamental purposes and utilized as a medicinal plant. In the present work, the hydroalcoholic extract from the aerial parts of this species has been evaluated in different bioassays in order to detect potential pharmacological applications. The cytotoxic capacity against the human colorectal adenocarcinoma (CaCo-2) and breast cancer (MCF-7) cell lines was tested using the MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. The extract was investigated as a neuroprotective inhibitor of central nervous system (CNS) enzymes such as monoamine oxidase A, tyrosinase, acetylcholinesterase, and as a natural enzyme inhibitor of a-glucosidase and lipase involved in some metabolic disorders such as obesity or type 2 diabetes. The antioxidant ability was also evaluated in an enzymatic system (xanthine/xanthine oxidase assay). Results showed that the M. incana extract displayed moderate to low cytotoxicity vs. CaCo-2 cells. The extract acted as a superoxide radical scavenger and enzymatic inhibitor of monoamine oxidase A, tyrosinase, a-glucosidase, and lipase. The best results were found in the a-glucosidase assay, as M. incana hydroalcoholic extract was able to inhibit the enzyme a-glucosidase up to 100% without significant differences, compared to the antidiabetic drug acarbose. Matthiola incana has been demonstrated to exert different biological properties. These are important in order to consider this species as a source of bioactive compounds

La solidaridad como respuesta a la soledad en las personas mayores

Ante un envejecimiento acelerado de la sociedad, especialmente en el mundo occidental y desarrollado, se constata actualmente que la soledad y el aislamiento no deseado entran a formar parte de la vida de muchas personas mayores, con las consecuencias y efectos negativos que esto supone en su salud, su bienestar físico, y emocional, y por consiguiente en la sociedad. La pandemia de la COVID-19 ha sacado a la luz esta realidad invisible, ya conocida. ¿Se puede mitigar o paliar esta situación? Desde las políticas, instituciones, empresas y el tercer sector se comentarán algunos de los recursos implementados para dar respuesta a esta situación. Para poder comprender la figura y estatus de las personas mayores, en el primer capítulo se hablará de la vejez de su dimensión multidisciplinar y de la propuesta de la OMS sobre el “Envejecimiento Saludable”. El capítulo II trata el tema de la soledad y su diversidad para acercarnos a esta realidad y buscar soluciones tanto para su prevención, como para paliar los efectos negativos que conlleva. Los capítulos III y IV intentan dar respuesta de manera somera a esta realidad: desde lo que ofrecen las políticas, las empresas de innovación tecnológica, hasta lo que la familia y las relaciones de vecindad y actividades sociales pueden aportar, sin dejar de lado el papel que supone el valor de la solidaridad en el voluntariado, buscando la oportunidad de convertir la “soledad” en “solidaridad”. En este último capítulo se recogen una selección de buenas prácticas, -desarrollados por Fundaciones, ONG y Asociaciones que de manera más directa contribuyen y trabajan para mitigar este sentimiento de soledad no deseada en las personas mayores