Complete analysis of pion-nucleon scattering in chiral perturbation theory to third order

We consider pion-nucleon scattering in heavy-baryon chiral perturbation theory to third order. All electromagnetic corrections appearing to this order are included. We thus have a consistent description of strong and electromagnetic effects, which allows us to isolate the strong part of the interaction in an unambiguous way. We give pion-nucleon phase shifts up to pion laboratory momenta of 100 MeV and find sizeable differences for the S-waves of the elastic channels compared to previous phase shift analyses. The precise description of the scattering process also allows us to address the question of isospin violation in the strong interaction. For the usually employed triangle relation we find an isospin breaking effect of -0.7% in the S-wave, whereas the P-waves show an effect of -1.5% and -4 to -2.5%, respectively, for pion laboratory momenta between 25 and 100 MeV.Comment: 17 pp, 7 fig

Spectroscopic features of low-energy excitations in skin nuclei

Systematic studies of dipole and other multipole excitations in stable and exotic nuclei are discussed theoretically. Exploring the relation of the strengths of low-energy dipole and quadrupole pygmy resonances to the thickness of the neutron (proton) skin a close connection between static and dynamic properties of the nucleus is observed. The fine structure of low-energy dipole strength in 138Ba nucleus is revealed from E1 and spin-flip M1 strengths distributions.Comment: A Talk given at the Int. Symposium 'Forefronts of Researches in Exotic Nuclear Structures - Niigata2010 -', 1-4 March, 2010, Tokamachi, Niigata, Japan; to be published in a volume of Modern Physics Letters A (MPLA)

Transiciones de los jóvenes residentes en los espacios públicos de Mar del Plata

Todo individuo atraviesa diferentes etapas de desarrollo y crecimiento a lo largo de su vida, las cuales pueden ser consideradas como transiciones que hacen a su trayectoria personal. El paso por ellas implica desde cambios biológicos hasta cambios culturales. Se realiza, desde un enfoque cualitativo, un análisis acerca de cuáles han sido las trayectorias juveniles de los jóvenes residentes de Mar del Plata. Para ello se indaga sobre los espacios públicos a los cuales han concurrido en su tiempo libre analizando de qué manera las experiencias de cada sujeto durante la niñez y la adolescencia pueden determinar sus comportamientos y elecciones en la etapa juvenil. Se evidencia que, el tiempo libre se presenta de manera desigual en las transiciones analizadas. Además, se identifica una variación en cuanto a los espacios públicos de la ciudad elegidos, dadas las condiciones particulares de los jóvenes entrevistados, su volumen global de capital, como así también del grupo social de pertenencia.Fil: Roldán, Nadia G. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina

Modalidad semipresencial como alternativa de enseñanza-aprendizaje en la Cátedra Introducción al Turismo de la Universidad Nacional de Mar del Plata

El actual desafío que se presenta a los docentes de los primeros años de las carreras universitarias, más allá de brindarles un conocimiento técnico y las herramientas necesarias para la formación profesional a los alumnos; consiste en acompañarlos en este espacio de formación de grado, el cual presenta diferencias evidentes con la educación de nivel medio. Se asume que las aulas virtuales presentan una lógica particular en donde el proceso de enseñanza-aprendizaje se realiza bajo ciertas estrategias pedagógicas que permiten a los alumnos poder adquirir los conocimientos y apropiarse de ellos al igual que surge en las aulas presenciales. Siendo necesario realizar una utilización provechosa de los diferentes recursos y espacios que ofrecen los entornos virtuales de aprendizaje, superando el uso simplificado de ser meramente un medio en donde los alumnos accedan a material de lectura. La presente producción tiene por objetivo dar a conocer la experiencia realizada durante el año 2014 en la Cátedra de Introducción al Turismo de la Universidad Nacional de Mar del Plata (UNMDP), al ofrecer un espacio de enseñanza aprendizaje semipresencial, en donde se complementan tanto el espacio presencial como el virtual, para acompañar a aquellos alumnos que deben recursar la asignatura por diversos motivos. Dado que se identificaba la presencia de alumnos que reiteradamente debían cursar la materia troncal "Introducción al Turismo" de la carrera de la Lic. en Turismo (UNMDP) para obtener su aprobación; el cuerpo docente propuso ofrecer una alternativa de cursado que se adapte a realidad de estos alumnos, manteniendo el nivel, contenido y la calidad educativa a la que aspira la Cátedra mediante una instancia de cursado semipresencial. La propuesta educativa pretendía por un lado, que los alumnos puedan adecuar sus tiempos de estudio en función del cursado de otras asignaturas y de sus jornadas laborales. Y por otro lado, que el docente realice un acompañamiento personalizado de cada alumno a través de la realización de trabajos prácticos integradores para cada unidad temática del programa, contemplando el uso de las herramientas que ofrece la plataforma Moodle. Más allá de la cantidad de alumnos que finalizaron exitosamente su paso por esta instancia de formación, se consideraba necesario conocer la opinión de los alumnos y dar cuenta de su experiencia. Es por ello que, al finalizar el cuatrimestre se les realizó una breve encuesta a través de la cual se les proponía realizar una valoración positiva o negativa, respecto de: uso del aula virtual, vínculo docente-alumnos, comunicación y otros aspectos que considerasen relevantes. Producto del análisis surge una valoración positiva de los alumnos, para quienes resultó un espacio favorable para la aprehensión de los conocimientos ofrecidos, destacando el vínculo que se generó entre el docente y los alumnos y dando cuenta de la necesidad de seguir contando con este espacio para los alumnos que se encuentren en la condición de recursantes. No obstante ello, proponen continuar reforzando el espacio de intercambio entre ellos y para con el docente a cargo, con intención de que se asemeje al diálogo de las aulas presenciales.The current challenge to teachers that is presented in the early years in university courses, beyond providing technical knowledge and tools needed for vocational training students; it is to accompany them in this area of undergraduate education, which has obvious differences with mid-level education. It is assumed that virtual classrooms have a particular logic in which the teaching-learning process is performed under certain teaching strategies that enable students to acquire knowledge and appropriate it just like in regular courses. Being necessary to make a profitable use of the different spaces that resources and virtual learning environments offer, overcoming the merely and simplified environment where students only get access to reading the pointed material. This production aims to publicize the experience gained during 2014 in the subject "Introducción al Turismo" held at the National University of Mar del Plata (UNMdP), by offering a blended learning and teaching space, complementing virtual and classroom classes, to accompany students that, for several reasons had to take the course again. Since the presence of students who repeatedly had to take the core subject "Introducción al Turismo" of the Licenciatura en Turismo (UNMdP) for approval; faculty proposed to offer an alternative that could suit the reality of these students keeping the level, content and quality of education through a combined virtual and classroom course. The educational proposal aimed on one hand, that students could adjust their time with other subjects and their working hours. On the other hand, that teachers could make a personalized accompaniment of each student through performing integrated practical works for each unit of the program with the help of the tools offered by Moodle. Beyond the number of students who successfully completed their passage through this stage of training it was considered necessary to know the opinion of students and report their experience. That is why, at the end of the quarter a brief survey was conducted through which they were intended to make positive or negative judgements about: use of the virtual classroom, the communication links between teacher and students and other aspects they could considered relevant. As product of the analysis a positive assessment of students arises, for whom the course turned out favorable for the apprehension of the knowledge offered, highlighting the link that is generated between the teacher and students and realizing the need to continue to have this space for students who must take the subjet again. Nevertheless, they propose to strengthen relationships between themselves and the teachers in charge, with the intention of generating resemblance to the kind of dialogue found in classroom activities.Fil: Roldán, Nadia G. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina

AN ANALYSIS OF JOKE TRANSLATION IN DATE NIGHT MOVIE

ABSTRACT Nadia Rimadhani Giusti. C0310041. 2015. An Analysis of Joke Translation in Date Night Movie. English Department. Faculty of Cultural Sciences. Sebelas Maret University Surakarta. This is a descriptive qualitative research which focuses on analyzing translation techniques and quality of international joke and national-culture-and-institutions joke found in a movie entitled Date Night. It aims at (1) explicating international joke and national-culture-and-institutions joke, (2) finding out the translation techniques applied by the translator to translate international joke and national-culture-and-institutions joke, and (3) explaining how the techniques affect the translation quality of international joke and national-culture-and-institutions joke, in terms of accuracy and acceptability. This research employs purposive sampling technique. Date Night is chosen as the source of data with international jokes and national-culture-and-institutions jokes taken as the data. The total data are 79 data which consist of 58 international jokes and 21 national-culture-and-institutions jokes. The other data are in the forms of information taken from the result of questionnaire given to the three raters and in-depth interview with them. The analysis of translation techniques shows that there are eight techniques used by the translator to translate international jokes and national-culture-and-institutions jokes, namely transfer, paraphrase, imitation, transcription, expansion, deletion, condensation, and decimation. Those techniques are applied as single techniques or combination of two to six techniques. There are 13 (16.46%) data translated using single techniques and 66 (83.54%) data translated using multiple techniques. The findings of the research in terms of translation quality show that 47 (59.49%) data of international joke are accurate, 11 (13.93%) data of international joke are less accurate, 14 (17.72%) data of national-culture-and-institutions joke are accurate, and seven (8.86%) data of national-culture-and-institutions joke are less accurate. The analysis on the acceptability reveals that 47 (59.49%) data of international joke are considered acceptable, 11 (13.93%) data of international joke are considered less acceptable, 16 (20.25%) data of national-culture-and-institutions joke are categorized into acceptable, and five (6.33%) data of national-culture-and-institutions joke are categorized into less acceptable. The technique which produces the largest number of accurate translation is transfer, as many as 61 (77.22%) data. Meanwhile, decimation produces the largest number of less accurate translation, as many as 11 (13.93%) data. Transfer is also the most dominant technique which results in acceptable translation, as many as 62 (78.48%) data. Meanwhile, less acceptable translation results from the use of uncommon terminologies, inappropriate dictions, unnatural expressions, and incomplete punctuation mark used by the translator. From the result, the translator has successfully translated most of the jokes. However, some jokes are less accurately or less acceptably translated because the translator uses wrong techniques or uses incomplete punctuation mark, inappropriate dictions, unnatural expressions, or uncommon terminologies. Keywords: joke translation, humor translation, types of joke, translation quality, translation techniqu

Excitation and Propagation of Eccentricity Disturbances in Planetary Systems

The high eccentricities of the known extrasolar planets remain largely unexplained. We explore the possibility that eccentricities are excited in the outer parts of an extended planetary disk by encounters with stars passing at a few hundreds of AU. After the encounter, eccentricity disturbances propagate inward due to secular interactions in the disks, eventually exciting the innermost planets. We study how the inward propagation of eccentricity in planetary disks depends on the number and masses of the planets and spacing between them and on the overall surface-density distribution in the disk. The main governing factors are the large-scale surface-density distribution and the total size of the system. If the smeared-out surface density is approximated by a power-law \Sigma(r)\propto r^{-q}, then eccentricity disturbances propagate inward efficiently for flat density distributions with q < 1. If this condition is satisfied and the size of the planetary system is 50 AU or larger, the typical eccentricities excited by this mechanism by field star encounters in the solar neighborhood over 5 Gyr are in the range 0.01-0.1. Higher eccentricities (> 0.1) may be excited in planetary systems around stars that are formed in relatively dense, long-lived open clusters. Therefore, this mechanism may provide a natural way to excite the eccentricities of extrasolar planets.Comment: 23 pages including 4 b/w figures and 1 color figure, accepted to A

Models of Galaxy Clusters with Thermal Conduction

We present a simple model of hot gas in galaxy clusters, assuming hydrostatic equilibrium and energy balance between radiative cooling and thermal conduction. For five clusters, A1795, A1835, A2199, A2390 and RXJ1347.5-1145, the model gives a good description of the observed radial profiles of electron density and temperature, provided we take the thermal conductivity $\kappa$ to be about 30% of the Spitzer conductivity. Since the required $\kappa$ is consistent with the recent theoretical estimate of Narayan & Medvedev (2001) for a turbulent magnetized plasma, we consider a conduction-based equilibrium model to be viable for these clusters. We further show that the hot gas is thermally stable because of the presence of conduction. For five other clusters, A2052, A2597, Hydra A, Ser 159-03 and 3C295, the model requires unphysically large values of $\kappa$ to fit the data. These clusters must have some additional source of heat, most likely an active galactic nucleus since all the clusters have strong radio galaxies at their centers. We suggest that thermal conduction, though not dominant in these clusters, may nevertheless play a significant role by preventing the gas from becoming thermally unstable.Comment: Published in ApJ; 22 pages, including 2 tables, 4 figures; typos corrected to match the published versio

von Neuman algebras of strongly connected higher-rank graphs

We investigate the factor types of the extremal KMS states for the preferred dynamics on the Toeplitz algebra and the Cuntz--Krieger algebra of a strongly connected finite $k$-graph. For inverse temperatures above 1, all of the extremal KMS states are of type I$_\infty$. At inverse temperature 1, there is a dichotomy: if the $k$-graph is a simple $k$-dimensional cycle, we obtain a finite type I factor; otherwise we obtain a type III factor, whose Connes invariant we compute in terms of the spectral radii of the coordinate matrices and the degrees of cycles in the graph.Comment: 16 pages; 1 picture prepared using TikZ. Version 2: this version to appear in Math. An

Not All SecA Proteins Are Created Equal: A Study of the SecA1 and SecA2 Proteins of Mycobacterium tuberculosis.

In bacteria, most secreted proteins are exported through the SecYEG translocon by the SecA ATPase motor via the general Sec pathway. The identification of an additional SecA protein, particularly in Gram-positive pathogens, has raised important questions about the role of SecA2 both in protein export and establishment of virulence. In Mycobacterium tuberculosis, the causative agent of Tuberculosis (TB), the accessory SecA2 protein possesses ATPase activity that is required for bacterial survival in host macrophages, highlighting its importance in virulence. This study probes the biochemical differences between the two SecA proteins in order to gain insight into how they interact with the same translocon to exporting specific precursors. The study shows that SecA2 unlike SecA1 does not associate with the membrane under normal conditions. SecA2 also binds ADP with much higher affinity than SecA1 and releases the nucleotide more slowly. Nucleotide binding regulates movement of the precursor-binding domain in SecA2, unlike in SecA1 or conventional SecA proteins. This conformational change involving closure of the clamp in SecA2 may provide a mechanism for the cell to direct protein export through the conventional SecA1 pathway under normal growth conditions while preventing ordinary precursor proteins from interacting with the specialized SecA2 ATPase