Shock formation in electron-ion plasmas: mechanism and timing

We analyse the full shock formation process in electron-ion plasmas in theory and simulations. It is accepted that electromagnetic shocks in initially unmagnetised relativistic plasmas are triggered by the filamentation instability. However, the transition from the first unstable phase to the quasi-steady shock is still missing. We derive a theoretical model for the shock formation time, taking into account the filament merging in the non-linear phase of the filamentation instability. This process is much slower than in electron-positron pair shocks, so that the shock formation is longer by a factor proportional to sqrt(m_i/m_e) ln(m_i/m_e)

Twice Scattered Particles in a Plane are Uniformly Distributed

It was recently shown (Physica A 216:299–315, 1995) that in two dimensions the sum of three vectors each of whose lengths is exponentially distributed, whose direction is uniformly distributed and such that the sum of their lengths is l, is uniformly distributed on a disk of radius l. We state here this random walk result in terms of scattering of particles as follows: in two dimensions twice isotropically scattered particles by random (i.e., Poisson distributed) scatterers are uniformly distributed. We show that there is no other dimension d and no other number of scatterings s for which the corresponding result (i.e., uniform distribution on a d-dimensional sphere after s scatterings) holds

Tratamiento percutáneo de las estenosis biliares en el trasplante hepático infantil

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Medicina. Fecha de lectura: 25-09-201

Survivability analysis of tape-tether against multiple impact with tiny debris

We show that for a tether at 800 km altitude, which is 5 km long, 2 cm wide and 0.05 mm thick, the risk of substantial damage during a 3 month period due to multiple impacts with debris or micrometeoroids is low, of about 1.4%. By substantial damage we mean that if the tape is divided in 2 cm2 cm squares, then in some square the damaged area by bombardment with debris or micrometeoroids exceeds 11% of the area of the square. Furthermore, we show that the danger posed by the micrometeoroids is negligible compared to the risk posed by the debris

Resistence of Euphorbia Heterophylla L. to ALS-inhibiting herbicides in soybean

Os herbicidas constituem a principal medida de controle de plantas daninhas na cultura da soja, mas através da pressão de seleção, o uso contínuo e prolongado de produtos com o mesmo mecanismo de ação pode provocar a manifestação de biótipos resistentes, como ocorreu com Euphorbia heterophylla L. aos inibidores da ALS nos Estados do Paraná, Rio Grande do Sul e São Paulo. Para verificar possíveis novos casos, bem como alternativas para prevenção e manejo, foram coletadas sementes dessa espécie daninha na região de Caarapó (MS), em plantas que sobreviveram a tratamentos onde esses herbicidas foram sistematicamente aplicados nos últimos anos. Em casa-de-vegetação, comparou-se o efeito dos principais herbicidas usados em pós-emergência na cultura da soja sobre o biótipo com histórico de resistência e sobre um suscetível sendo instalado, um experimento em blocos ao acaso para cada produto (n = 4). Os herbicidas foram aplicados quando as plantas apresentavam de duas a quatro folhas verdadeiras nas doses zero, uma, duas, quatro e oito vezes a recomendação do fabricante. Aos vinte dias após a aplicação, foram avaliados parâmetros relativos ao controle e produção de fitomassa epígea com base nos valores de DC50 e GR50. Foi determinado também o fator de resistência (FR), que representa o número de vezes em que a dose necessária para proporcionar 50% de controle ou de redução na produção de fitomassa epígea do biótipo suscetível deve ser aumentada, para que possa ocorrer o mesmo efeito sobre o resistente. O biótipo resistente apresentou diferentes níveis de resistência aos herbicidas chlorimuron-ethyl e imazethapyr, demonstrando ser portador de resistência cruzada aos inibidores da ALS dos grupos das sulfoniluréias e imidazolinonas. O fator de resistência para chlorimuron-ethyl foi superior a 16,5 para a porcentagem de controle e a 16,9 para a produção de fitomassa epígea, enquanto que para imazethapyr, o fator de resistência foi superior a 25,0 e a 23,5, respectivamente. O biótipo resistente foi eficientemente controlado nos tratamentos com os herbicidas fomesafen (250 g ha-1), lactofen (120 g ha-1), flumiclorac-pentil (40 g ha-1), glufosinato de amônio (150 g ha-1) e glyphosate (360 g ha-1).Herbicides are widely used in soybean for weed control, and the selection pressure attributed to the repeated use of herbicides with similar modes of action on the same site has caused selection for resistant biotypes within and among previously susceptible species, such as Euphorbia heterophylla L., in relation to ALS enzyme inhibitors, in the states of Paraná, Rio Grande do Sul, and São Paulo, Brazil. Seeds of E. heterophylla were collected to examine possible new cases of resistant populations and to test alternative herbicide treatments to manage these populations, in the Caarapó region, State of Mato Grosso do Sul, Brazil, in areas where plants of this species have survived continuous herbicide applications. The experiment was carried out under greenhouse conditions, where biotypes with a history of suspected resistance were compared with a known susceptible biotype. Several post-emergence herbicides were sprayed at zero, one, two, four, and eight times the recommended field application rates. Twenty days after application, plants were harvested, and control percentage and fresh weight were determined to establish dose-response curves, in the aim to obtain the resistance factor using CD50 and RD50 data. The chlorimuron-ethyl resistance factor values for the control percentage and fresh weight parameters were higher than 16.5 and 16.9, respectively, while imazethapyr showed resistance factors higher than 25.0 and 23.5, respectively. The resistant biotype showed different resistance levels to chlorimuron-ethyl and imazethapyr, showing cross-resistance to the sulfonylurea and imidazolinone groups. Nevertheless, this biotype was effectively controlled by fomesafen (250 g ha-1), lactofen (120 g ha-1), flumiclorac-pentyl (40 g ha-1), glufosinate-ammonium (150 g ha-1), and glyphosate (360 g ha-1)

Building and Collapse of the Cadomian Orogen: A Plate-Scale Model Based on Structural Data From the SW Iberian Massif

The Cadomian Orogeny produced a subduction-related orogen along the periphery of Gondwana and configured the pre-Variscan basement of the Iberian Massif. The architecture of the Cadomian Orogen requires detailed structural analysis for reconstruction because of severe tectonic reworking during the Paleozoic (Variscan cycle). Tectonometamorphic analysis and data compilation in SW Iberia (La Serena Massif, Spain) have allowed the identification of three Cadomian deformation phases and further constrained the global architecture and large-scale processes that contributed to the Ediacaran building and early Paleozoic dismantling of the Cadomian Orogen. The first phase (DC1, prior to 573 Ma) favored tabular morphology in plutons that intruded during the building of a continental arc. The second phase (DC2, 573–535 Ma) produced an upright folding and contributed to further crustal thickening. The third phase of deformation (DC3, ranging between ∼535 and ∼480 Ma) resulted in an orogen-parallel dome with oblique extensional flow. DC1 represents the crustal growth and thickening stage. DC2 is synchronous with a period of crustal thickening that affected most of the Gondwanan periphery, from the most external sections (Cadomian fore-arc) to the inner ones (Cadomian back-arc). We explain DC2 as a consequence of flat subduction, which was followed by a period dominated by crustal extension (DC3) upon roll-back of the lower plate. The Ediacaran construction of the Cadomian Orogen (DC1 and DC2) requires ongoing subduction beneath Gondwana s.l., whereas its dismantlement during the Early Paleozoic is compatible with oblique, sinistral convergence.Projects PID2020-112489GB-C21 and PID2020-112489GB-C22, funded by MCIN/AEI/10.13039/50110001103

Developing Emotional Intelligence with a Game: The League of Emotions Learners Approach

Being able to understand, express, and communicate emotions is widely recognized as a fundamental competence. For the younger generation entering the professional market, this is particularly relevant as, in this context, emotions are managed and communicated in ways (and channels) that are different from what they are used to and that can easily lead to misunderstandings. Therefore, it is important to analyze how young people deal with, understand, and interpret emotions, particularly in the context of a professional career where the ability to dialogue with different people and how to get around problems in a healthy and resilient way is essential. This analysis will allow one to design and create tools that allow the younger generation to improve their emotional intelligence and competence. This article introduces the League of Emotions Learners (LoEL) project, an innovative initiative that, through a game app, develops the emotional competence and intelligence of young people. The article then presents the results obtained in the initial validation that led to the positive understanding of its impact.This research was partly funded by the European Union, through the Erasmus+ programme, KA2 action, under the grant number 2018-1-ES02-KA205-011836.info:eu-repo/semantics/publishedVersio

Survivability analysis of tape-tether against two concurring impacts with debris

It has recently been shown that a thin-tape tether, as opposite to a round one, has a high probability of survival to single impacts by space debris, under a broad range of de-orbit operation conditions. The purpose of the present work is to extend that analysis to survival to multiple impacts by smaller, but more abundant, debris. The method used here consist, essentially, in separating the particles into “large” and “small” ones. The large ones are so rare that the probability of them concurring on the same spot can be neglected. The small ones are a sort of background, and it is shown that the probability of them impinging close enough to a large particle crater to cause malfunction of the tape is negligible. A particular mission is considered, de-orbiting a 3000 kg spacecraft from 800 km altitude at 90°90° inclination by means of an aluminium tape of dimensions 10,000 m × 0.06 m × (5 × 10−5) m. It is shown that the probability that this mission survives to multiple impacts is at least 0.978. The application of this method to missions of different parameters is also discus

Different Non-Target Site Mechanisms Endow Different Glyphosate Susceptibility in Avena Species from Spain

In recent decades, cereal agriculture across main producing areas in Spain has progressively adopted direct sowing, associated with an increased use of herbicides in pre-sowing. Weedy species from genus Avena have been observed after the application of glyphosate in wheat. Here, Avena fatua (two accessions), Avena byzantina and Avena sterilis subsp. sterilis, one accession each, were taxonomically characterized by a biometric study. Dose-response trials confirmed that one A. fatua accession evolved to resistance, because it was four times more resistant (R) than the others, ascribed as susceptible (S). In addition, based on LD50, A. byzantina and A. sterilis had low susceptibility to glyphosate, with 604 and 458 g ae ha−1. Shikimic acid accumulation was able to discriminate between high susceptible (A. fatua (S)), low susceptible (A. byzantina and A. sterilis), and low resistant (A. fatua (R)) populations. On the other hand, the study revealed that A. fatua (R), A. byzantina and A. sterilis had low foliar uptake and decreased movement of glyphosate. In addition, the metabolism study showed less metabolite accumulation in A. byzantina and A. fatua (S). However, at 96 h after glyphosate application, A. fatua (R) and A. sterilis were able to convert more than 30% of glyphosate to aminomethylphosphonic acid (AMPA) and sarcosine. Enzyme basal activity and I50 values predicted high affinity between the herbicide and the target enzyme for all accessions, thus indicating that a target-site (TS) mechanism is probably not involved in the differences in glyphosate susceptibility. In closing, non-target site (NTS) mechanisms could participate both in A. fatua R to glyphosate, and low susceptibility in A. byzantina and A. sterilis from Spain

Influencia de la asimetría en el patrón de la marcha en sujetos cubanos

Este trabajo presenta los elementos esenciales a tener en cuenta para el análisis de la manifestación de la asimetría en el patrón biomecánico de la marcha y tiene como objetivo describir los parámetros de flexo extensión de rodilla y tobillo con la intención de proporcionar un criterio de ayuda para la obtención de un patrón de marcha que contenga el estudio de las asimetrías y contribuya al diagnóstico y tratamiento de patologías. Para ello se realizó una comparación de los datos cuantitativos que caracterizan los parámetros cinemáticos de la marcha, obtenidos en un laboratorio de captura de movimiento con sistema Vicon. Esta comparación se realizó usando una muestra de 5 sujetos de diferentes edades, peso, estatura y sexo. La importancia radica en que a partir de los resultados obtenidos en esta comparación se puede asumir algunos criterios que influirán en la correcta determinación del patrón biomecánico de la marcha en sujetos sanos. Estos estándares ofrecen una invaluable ayuda en el desarrollo clínico e investigativo, permitiendo detectar alteraciones, ejecutar control y seguimiento, evaluar la efectividad de los tratamientos indicados, o determinar modelos en el diseño en la ingeniería biomédica