Dynamics of a Rydberg hydrogen atom near a topologically insulating surface

We investigate the classical dynamics of a Rydberg hydrogen atom near the surface of a planar topological insulator. The system is described by a Hamiltonian consisting of the free-hydrogen part and the hydrogen-surface potential. The latter includes the interactions between the electron and both image electric charges and image magnetic monopoles. Owing to the axial symmetry, the $z$ component of angular momentum $l_{z}$ is conserved. Here we consider the $l_{z} = 0$ case. The structure of the phase space is explored extensively by means of numerical techniques and Poincar\'{e} surfaces of section for the recently discovered topological insulator TlBiSe$_{2}$. The phase space of the system is separated into regions of vibrational and rotational motion. We show that vibrational-rotational-vibrational type transitions can be tuned with the topological magnetoelectric polarizability.Comment: Accepted for publication in Europhysics Letter

Introducción a la citología digestiva en pequeños animales

La citología es un método de diagnóstico atractivo para el veterinario clínico por ser técnicamente simple, rápido y económico. La endoscopia ha permitido que la citología digestiva sea además mínimamente invasiva. Los resultados de la citología dependen de una buena obtención y preparación de las muestras así como de nuestra capacidad para identificar los diferentes tipos celulares presentes. En este artículo se exponen de forma fácil y práctica los fundamentos necesarios para una aproximación eficaz a la citología diagnóstica digestiva: equipos endoscópicos más aconsejables, selección, obtención y número de biopsias, y las bases para la identificación de las células presentes en las muestras del tracto digestivo en perro y gato.Cytology is an easy, fast cost-effective diagnostic method very atíractive to practitioners. Also, the advent of endoscopy has made gastrointestinal tract cytology a non invasive method. However, results of the cytologic analysis depend on a proper obtention and preparation of the samples and on our skill to identify the different cell types observed. In this article the essentials for an effective approach to diagnostic gastrointestinal tract cytology are presented: endoscopy equipment, selection, obtention and number of biopsy samples and the basis for the identification of cells present in the digestive tract of dogs and cats

Nature s Top 100 Re-Revisited

"This is the peer reviewed version of the following article: Martín-Martín, A., Ayllon, J. M., López-Cózar, E. D., & Orduna-Malea, E. (2015). Nature's top 100 Re-revisited. JASIST, 66(12), 2714., which has been published in final form at http://doi.org/10.1002/asi.23570. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."To mark the 50th anniversary of the Science Citation Index, Nature published a list of the 100 most-cited papers of all time. It also included an alternative ranking from data provided by Google Scholar, which, as this letter illustrates, contains certain inconsistencies. This does not, however, diminish the usefulness of Google Scholar, not only in identifying the most-cited articles of all time, but also in reflecting the impact of other document types (especially books), thus redefining the concept of academic impact. Keywords:Martín-Martín, A.; Ayllón, JM.; Delgado López-Cózar, E.; Orduña Malea, E. (2015). Nature s Top 100 Re-Revisited. Journal of the American Society for Information Science and Technology. 66(12):2714-2714. doi:10.1002/asi.23570271427146612Bornmann , L. Nature's top 100 revisited. Journal of the Association for Information Science and Technology http://www.lutz-bornmann.de/icons/top_100.pdfGarfield , E. 2005 The agony and the ecstasy-the history and meaning of the Journal Impact Factor http://www.garfield.library.upenn.edu/papers/jifchicago2005.pdfMartin-Martin , A. Orduna-Malea , E. Ayllon , J.M. Delgado Lopez-Cozar , E. 2014 Does Google Scholar contain all highly cited documents (1950-2013)? http://arxiv.org/abs/1410.8464Van Noorden, R., Maher, B., & Nuzzo, R. (2014). The top 100 papers. Nature, 514(7524), 550-553. doi:10.1038/514550

Using binary statistics in Taurus-Auriga to distinguish between brown dwarf formation processes

Whether BDs form as stars through gravitational collapse ("star-like") or BDs and some very low-mass stars constitute a separate population which form alongside stars comparable to the population of planets, e.g. through circumstellar disk ("peripheral") fragmentation, is one of the key questions of the star-formation problem. For young stars in Taurus-Auriga the binary fraction is large with little dependence on primary mass above ~0.2Msun, while for BDs it is <10%. We investigate a case in which BDs in Taurus formed dominantly through peripheral fragmentation. The decline of the binary frequency in the transition region between star-like and peripheral formation is modelled. A dynamical population synthesis model is employed in which stellar binary formation is universal. Peripheral objects form separately in circumstellar disks with a distinctive initial mass function (IMF), own orbital parameter distributions for binaries and a low binary fraction. A small amount of dynamical processing of the stellar component is accounted for as appropriate for the low-density Taurus-Auriga embedded clusters. The binary fraction declines strongly between the mass-limits for star-like and peripheral formation. The location of characteristic features and the steepness depend on these mass-limits. Such a trend might be unique to low density regions hosting dynamically unprocessed binary populations. The existence of a strong decline in the binary fraction -- primary mass diagram will become verifiable in future surveys on BD and VLMS binarity in the Taurus-Auriga star forming region. It is a test of the (non-)continuity of star formation along the mass-scale, the separateness of the stellar and BD populations and the dominant formation channel for BDs and BD binaries in regions of low stellar density hosting dynamically unprocessed populations.Comment: accepted for publication in A&A, 11 pages, 4 figures, 1 tabl

Identification of the water stress level in olive trees during pit hardening using the trunk growth rate indicator.

Water scarcity is generating an increasing interest in deficit irrigation scheduling. The trunk diameter fluctuations are daily cycles that have been suggested as tools for irrigation scheduling. The trunk growth rate (TGR) was suggested as the best indicator for olive trees during pit hardening. The aim of this work is to clarify how the TGR could be used to identify water stress levels. The experiment was performed during the 2017 season, in a commercial, super-high-density orchard in Carmona (Seville, Spain). Four different irrigation treatments were performed according to midday stem water potential values and TGR. The data obtained were very variable and both indicators presented a wide range of water status throughout the season. The maximum trunk diameter data clearly showed the pattern of the trees water status but the comparison between treatments and the identification of the water stress level was not possible. The average TGR was linked to the midday stem water potential, but with a minimum amount of data. Irrigation scheduling based on the average TGR was difficult because of the great increases in some daily TGR values. For clarity, the pool of data was grouped by midday stem water potential. These water stress levels were characterized using the weekly frequency of TGR values. The increase of water stress reduced the frequency of values between -0.1 and 0.3mm day-1 from 60% to less than 25%. Moderate water stress levels increased the percentage of values lower than -0.3mm day-1 from 7% to 37%. The most severe water stress conditions increased the TGR values between -0.3 and -0.1mm day-1 from 16% up to 22%.IRNASINSTITUTO DE LA GRASACSI