The complex dust formation zone of the AGB star IRC+10216 probed with CARMA 0.25 arcsec angular resolution molecular observations

We present low spectral resolution molecular interferometric observations at 1.2 mm obtained with the Combined Array for Research in Millimetre-wave Astronomy (CARMA) towards the C-rich AGB star IRC+10216. We have mapped the emission of several lines of SiS, H13CN, SiO, and SiC2 in the ground and first excited vibrational states with a high angular resolution of 0.25 arcsec. These observations have allowed us to partially resolve the emission of the envelope at distances from the star <50 stellar radii (R*), where the stellar wind is mainly accelerated. The structure of the molecular emission has been modelled with a 3D radiation transfer code. The emission of line SiS(v=0,J=14-13) is best reproduced with a set of maser emitting arcs arranged between 5 and 20 R*. The abundance of H13CN with respect to H2 decreases from 8e-7 at 1-5 R* to 3e-7 at 20 R*. The SiO observations are explained with an abundance <2e-8 in the shell-like region between 1 and 5 R*. At this point, the SiO abundance sharply increases up to (2-3)e-7. The vibrational temperature of SiO increases by a factor of 2 due North-East between 20 and 50 R*. SiC2 is formed at the stellar surface with an abundance of 8e-7 decreasing down to 8e-8 at 20 R* probably due to depletion on to dust grains. Several asymmetries are found in the abundance distributions of H13CN, SiO, and SiC2 which define three remarkable directions (North-East, South-Southwest, and South-East) in the explored region of the envelope. There are some differences between the red- and blue-shifted emissions of these molecules suggesting the existence of additional asymmetries in their abundance distributions along the line-of-sight.Comment: 22 pages, 16 figures, 9 tables, accepted for publication in MNRA

Agricultura de terrazas en el cerro Tenismo, Toluca. México

Los campesinos mexicanos practican diversos agroecosistemas tradicionales, caso particular, las terrazas.Los campesinos mexicanos practican diversos agroecosistemas tradicionales, caso particular, las terrazas. Este sistema es uno de los más antiguos en el Valle de Toluca y actualmente se encuentra en proceso de abandono. El objetivo fue caracterizar el sistema de terrazas del cerro Tenismo en Calixtlahuaca, Toluca, México, destacando sus componentes principales: muros de contención, zanja, vegetación, cultivos. A partir de la investigación cualitativa, observación directa y la descripción del agroecosistema, se analizan los componentes de quince terrazas de la ladera media y ladera alta del cerro Tenismo. Los resultados indican que las terrazas de Calixtlahuaca con muro de roca y metepantles (semiterraza), son un sistema importante que contribuye a la conservación de las laderas y de donde se obtienen cultivos de autoconsumo. Se concluye que el manejo que realizan los campesinos por medio de las terrazas (muros, zanjas y vegetación) tiene características agroecológicas que contribuyen a la preservación del ambiente.Universidad Autónoma del Estado de México Colegio de Ciencias Geográficas del Estado de México AC

Suppression of the intrinsic stochastic pinning of domain walls in magnetic nanostripes

Nanofabrication has allowed the development of new concepts such as magnetic logic and race-track memory, both of which are based on the displacement of magnetic domain walls on magnetic nanostripes. One of the issues that has to be solved before devices can meet the market demands is the stochastic behaviour of the domain wall movement in magnetic nanostripes. Here we show that the stochastic nature of the domain wall motion in permalloy nanostripes can be suppressed at very low fields (0.6-2.7 Oe). We also find different field regimes for this stochastic motion that match well with the domain wall propagation modes. The highest pinning probability is found around the precessional mode and, interestingly, it does not depend on the external field in this regime. These results constitute an experimental evidence of the intrinsic nature of the stochastic pinning of domain walls in soft magnetic nanostripe

Sensing the difference: the influence of anisotropic cues on cell behavior

From tissue morphogenesis to homeostasis, cells continuously experience and respond to physical, chemical and biological cues commonly presented in gradients. In this article we focus our discussion on the importance of nano/micro topographic cues on cell activity, and the role of anisotropic milieus play on cell behavior, mostly adhesion and migration. We present the need to study physiological gradients in vitro. To do this, we review different cell migration mechanisms and how adherent cells react to the presence of complex tissue-like environments and cell-surface stimulation in 2D and 3D (e.g. ventral/dorsal anisotropy)

Cara a cara ante los limites del conocimiento

¿Puede el ser humano asimilar la larga lista de importantes hallazgos científicos que se suceden cada día? ¿Como puede asumir éticamente tal vértigo? ¿Se puede pensar sin estar atento a avances como la secuenciación del Genoma Humano o la ingeniería genética? Los profesores José Manuel Sánchez Ron, catedrático de Historia de la Ciencia de la Universidad Autónoma de Madrid, y Francisco García Olmedo, catedrático de Biología Molecular de la Universidad Politécnica, hablan sobre estos interrogantes en un momento en el que se cuestionan valores asumidos durante milenios. Ambos publican estos días, respectivamente, El futuro es un país tranquilo (Espasa) y Entre el placer y la necesidad (Crítica)

Power Factor Corrector Design applied to an 85-kHz Wireless Charger

Wireless charging technology extends the battery autonomy by allowing more flexible and practical ways of recharging it even when the electric vehicle is on move. The frequency conversion, which is required to generate a kHz-ranged magnetic field, also leads to considerable harmonics. As a result, the power factor and the corresponding efficiency decrement. This paper proposes a Power Factor Corrector which overcomes this drawback. The most relevant feature of the designed Power Factor Corrector is that it does not need any electrical signal from the secondary side to adjust its operation properly. The simulation results show the ability of the proposed scheme to increment the system efficiency for different State-Of-Charge in the Battery.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Evaluation of losses in a bidirectional wireless power transfer system for electric vehicles

Inductively power transfer systems are becoming increasingly popular in modern applications like electric vehicles. In order to make this technology attractive, its transfer efficiency must be considerably high. Most works in the literature define the efficiency of the wireless charger as the one associated to the inverter, the coupled coils and the compensation networks. Therefore, they usually omit the study of the losses occurring in other parts of the system such as in the secondary rectifier. This paper evaluates the losses in a complete wireless charger, built and designed to provide V2G functionalities. The experimental evaluation based on the waveform analysis is contrasted with a theoretical model, which relies on the non-idealities of the components. The evaluation reveals that measurement error greatly impact on the power losses derived by the two approachesUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Editorial statement: The first year of the European Journal of Government and Economics

<p>In this editorial statement we present a balance of the first year of life of the <em>European Journal of Government and Economics</em>. We discuss the main developments that concern the journal’s indexation by academic databases. We also comment on the approval of a code of publication ethics and malpractice. Finally, we emphasise the dangers of excessive technical sophistication and the need to keep an integrated approach between the fields of political science and economics, according to the spirit of the journal.</p

Editorial statement: The first two years of EJGE

In this editorial statement we explain the developments in the European Journal of Government and Economics in its second year of existence. In this period, the journal has continued its international expansion, entered some new indices and started to experience its impact, as measured by the number of citations in other journals. After two years of publication, we have also learned some lessons that should help us redefine the role of EJGE

Editorial statement: Why do we need a European Journal of Government and Economics?

In this editorial statement we explain the reasons for the creation of the European Journal of Government and Economics. We argue that there is a general shortage of academic journals. Although the new journal we are starting will not solve or significantly reduce this problem, it will represent a marginal step in the right direction. We also explain our views regarding some important aspects of the journal’s policy, such as indexing and open access