Vortex Filament Equation for a regular polygon in the hyperbolic plane

The aim of this article is twofold. First, we show the evolution of the vortex filament equation (VFE) for a regular planar polygon in the hyperbolic space. Unlike in the Euclidean space, the planar polygon is open and both of its ends grow exponentially, which makes the problem more challenging from a numerical point of view. However, with fixed boundary conditions, a finite difference scheme and a fourth-order Runge--Kutta method in time, we show that the numerical solution is in complete agreement with the one obtained from algebraic techniques. Second, as in the Euclidean case, we claim that, at infinitesimal times, the evolution of VFE for a planar polygon as the initial datum can be described as a superposition of several one-corner initial data. As a consequence, not only can we compute the speed of the center of mass of the planar polygon, but the relationship also allows us to compare the time evolution of any of its corners with that in the Euclidean case

On the Evolution of the Vortex Filament Equation for regular M-polygons with nonzero torsion

In this paper, we consider the evolution of the Vortex Filament equa- tion (VFE): Xt = Xs ∧ Xss, taking M-sided regular polygons with nonzero torsion as initial data. Us- ing algebraic techniques, backed by numerical simulations, we show that the solutions are polygons at rational times, as in the zero-torsion case. However, unlike in that case, the evolution is not periodic in time; more- over, the multifractal trajectory of the point X(0,t) is not planar, and appears to be a helix for large times. These new solutions of VFE can be used to illustrate numerically that the smooth solutions of VFE given by helices and straight lines share the same instability as the one already established for circles. This is accomplished by showing the existence of variants of the so-called Rie- mann’s non-differentiable function that are as close to smooth curves as desired, when measured in the right topology. This topology is motivated by some recent results on the well-posedness of VFE, which prove that the selfsimilar solutions of VFE have finite renormalized energy

Pinset : A DSL for extracting datasets from models for data mining-based quality analysis

Data mining techniques have been successfully applied to software quality analysis and assurance, including quality of modeling artefacts. Before such techniques can be used, though, data under analysis commonly need to be formatted into two-dimensional tables. This constraint is imposed by data mining algorithms, which typically require a collection of records as input for their computations. The process of extracting data from the corresponding sources and formatting them properly can become error-prone and cumbersome. In the case of models, this process is mostly carried out through scripts written in a model management language, such as EOL or ATL. To improve this situation, we present Pinset, a domain-specific language devised for the extraction of tabular datasets from software models. Pinset offers a tailored syntax and built-in facilities for common activities in dataset extraction. For evaluation, Pinset has been used on UML class diagrams to calculate metrics that can be employed as input for several fault-prediction algorithms. The use of Pinset for this calculations led to more compact and high-level specifications when compared to equivalent scripts written in generic model management languages

Primary and secundary school physical education teachers’ beliefs

El estudio ha tenido el propósito de analizar el conocimiento de la percepción de las competencias profesionales que tiene el profesor de educación física en primaria y secundaria, como uno de los aspectos que determinan la identidad de la educación física como materia escolar, para dar respuesta al análisis del estado de la educación física desde esta perspectiva. Participaron 119 docentes de Castilla-La Mancha de primaria y secundaria, a los que se les aplicó parte de la "Escala de Percepción de la eficacia de los docentes"; concretamente las preguntas referidas a la percepción sobre las competencias docentes que tienen los profesores; diseñado y validado por el grupo de investigación (GIEEAFyD-UAM), liderado por Hernández et al., (2010). Los resultados muestran que los profesores de primaria se perciben más competentes que los profesores de secundaria en la gestión/organización de la clase y en el conocimiento didáctico de la enseñanza; las diferencias son significativas en la percepción del dominio del contenido de enseñanza y no se hallan diferencias en la capacidad de liderazgo y de relación con otros agentesThe study has analyzed physical education teachers’ self-perception of their professional competences in primary and secondary school, as one of the aspects that determines physical education identity as a school subject. The main purpose of the analysis is to review the status of physical education from this perspective. 119 primary and secondary school teachers from Castilla-La Mancha took part in the study, which applied part of the Scale of Perception of Teachers´ Efficiency, designed and validated by the research group GIEEAFyD-UAM (Hernández et al. 2010), and, more specifically, those questions referred to teachers’ perception of their own educational competences; The results revealed that primary school teachers regard themselves as more competent than secondary school teachers in classroom management/organization and in teaching methodology. Differences are significant in participants’ perception of their command of the content and there are no differences in leadership qualities and neither in the relation to other education agent

The antenna DSA 3 and its potential use for Radio Astronomy

The European Space Agency (ESA) will inaugurate its third Deep Space Antenna (DSA 3) by the end of 2012. DSA 3 will be located in Argentina near the city of Malarg"ue in the Mendoza province. While the instrument will be primarily dedicated to communications with interplanetary missions, the characteristics of its antenna and receivers will also enable standalone leading scientific contributions, with a high scientific-technological return. We outline here scientific proposals for a radio astronomical use of DSA 3.Comment: 4 pages, submitted as Proceedings for the BAA

Identifying gaps between science and practitioners perspectives on land use: the case of managed realignment in the German Baltic coast

Through state-of-the art ecosystem modelling supported by ecological experimental data, the COMTESS Project (funding: German Federal Ministry of Education and Research) investigates potential synergies and trade offs in ecosystem service provision under different land-use scenarios in two German coastal areas till 2100. Overall goal is to explore alternative sustainable land-use strategies to best adapt to climate change. Two science-based land- use scenarios were developed for two study regions on the Baltic and North Sea coasts to contrast a business-as-usual scenario. We focus here on the Baltic Se case region. The underlying premise of these alternatives is managed realignment of current dikes inland for: 1) climate mitigation through wetland re-naturation or 2) multiple land use, including biomass harvesting for energetic purposes (Baltic Sea). Managed realignment is increasingly considered as a valid coastal defence strategy to lower long-term costs of hard coastal defence and restore critical coastal and experiments have been initiated since the 1990s in a number of northwest European countries. Though politically highly controversial and facing much public antagonism, managed realignment is effectively embedded in the current coastal management policy of the state of Mecklenburg Vorpommern on the German Baltic coast. Implementation, nevertheless, faces many obstacles. Project-based scenarios for the Baltic Sea were first evaluated by key regional and local policy, management and land use practitioners, each expert in their field of activity. Their evaluation and recommendations were subsequently used to develop a fourth land-use scenario. Using qualitative empirical social research methods we analyse divergences and convergences between expert views on the projects scenarios. We argue that managed realignment is currently being mainstreamed in science, policy and resource management arenas although representatives of local land users and inhabitants do not endorse this strategy and still foster a hard defence approach to coastal zone management. This is best illustrated in recurrent social mobilisation and resistance to managed realignment proposals. This points at important perception and preference gaps between science, policy and land users / inhabitants, which need to be resolved to formulate and implement sustainable and socially acceptable land use strategies

Growth and bacterial dynamics of beef calves during transition from milk/pasture to a high-concentrate diet added with tannins or medium-chain fatty acids

Context. Rumen fermentation modulation with feed additives during the transition period to high-concentrate diets might help to avoid bacterial dysbiosis. Aims. Assessing the effects of the addition of tannins and medium-chain fatty acids (MCFA) to the adaptation diet of beef calves to a high-concentrate ration on the rate of intake, animal performance and rumen bacterial composition. Methods. Eighteen 7-month-old beef calves were abruptly weaned and transitioned over a 28-day period from a milk/grass regime to one of the following diets: a non-supplemented high-concentrate diet plus wheat straw, both given ad libitum (C); C plus 20 g/kg of a 65:35 chestnut and quebracho tannin extract; and C plus 6 g/kg of a commercial mixture of MCFA. Concentrate and straw rate of intake were recorded. Rumen fluid was collected on Days 0, 1, 7, 14, 21 and 28 at 0, 3, 6 and 9 h after feeding to characterise rumen fermentation. Samples from 0 h were analysed to assess the bacterial population using Ion Torrent sequencing. Key results. The rate of intake of concentrates and straw, as well as daily gains and final weights, were similar (P > 0.05) among diets. The addition of tannins or MCFA did not modify (P = 0.98) the rumen bacterial population, which was affected by sampling day (P < 0.001). The additives inclusion did not affect relative abundances of the main bacterial taxa (P < 0.05), most of them differing across days (P < 0.001). Diversity indexes (Shannon and richness) declined over sampling days (P < 0.05), although some genera emerged after concentrate inclusion. Conclusions. At the doses used in the present experiment, tannins and MCFA did not exert any effect on intake, animal performance and bacterial population. Abrupt transition to high-concentrate diets modified the rumen environment and bacterial community, indicating bacterial adaptation to new environmental conditions. Implications. Abrupt transition of 7-month-old calves from milk/pasture to a high-concentrate diet did not impair rumen microbiota or performance; therefore, the use of feed additives seems unnecessary. © 2021 CSIRO. All rights reserved

Analysis and evaluation of levels of awareness and understanding of fooball tactics by a game board

El siguiente estudio aborda la relación existente entre el plano de acción y el plano de representación de los sujetos, a través del papel que proporcionan los procesos de comprensión y toma de conciencia que suceden en el interior del individuo cuando se enfrenta a situaciones de juego que demanda un deporte no lineal, con características sumamente abiertas, como es el fútbol. El objetivo que pretendemos es analizar y evaluar la toma de conciencia y comprensión táctica del jugador infantil de fútbol base, desde la perspectiva funcional-estructural. Para ello, se ha utilizado un juego de tablero simulador de fútbol, diseñado a partir de la reglamentación básica que rige este deporte. La muestra utilizada está compuesta por ocho sujetos varones de categoría infantil, divididos en dos niveles de pericia: alto y bajo. Por tanto, se trata de un análisis centrado en el jugador (Garganta, 2001). Los ítems utilizados para realizar este análisis de la comprensión táctica de los jugadores se pueden categorizar siguiendo los principios tácticos de juego en fútbol que detalla Claude Bayer (1987). A su vez, los contenidos tácticos que se detallan en los ítems, se clasifican en aspectos tácticos de tipo individual -ofensivo y defensivo-, grupal -ofensivo y defensivo- y colectivo -ofensivo y defensivo-, siguiendo las clasificaciones propuestas por Fradua (1997), Garganta y Pinto (1997), Sánchez y Fradua (2001).The following study addresses the relationship between the level of action and the level of representation of the subject, through the paper that provide the processes of understanding and awareness that occur within the individual when confronted with game situations sport demands a nonlinear, with features very open, like football. The objective we intend to analyze and evaluate the awareness and tactical understanding of children's football player base, from the structural-functional perspective. For this, we used a board game football simulator, designed from the basic regulations governing the sport. The sample is composed of eight junior class male subjects, divided into two skill levels: high and low. Therefore, an analysis is centered on the player (throat, 2001). The items used for this analysis of tactical understanding of the players can be categorized according to the principles of tactical football game detailing Claude Bayer (1987). In turn, the contents listed in tactical items are classified in tactical aspects of individual type-offensive and defensive-, group-offensive and defensive-and collectiveoffensive and defensive-, following the classification proposed by Fradua (1997 ), Throat and Pinto (1997), Sanchez and Fradua (2001)