Does the anaesthetic influence behavioural transmission of the monogenean Gyrodactylus gasterostei Glaser, 1974 off the host?

The aim of this study was to investigate the use of the anaesthetic 2-phenoxyethanol on the transmission factors of gyrodactylid and to ascertain how this may affect in the colonisation of new hosts using the Gyrodactylus gasterostei Glaser, 1974 - Gasterosteus aculeatus L. model which is a simple and successful system to examine aspects of transmission of parasites from live and dead fish. Laboratory experiments include determining the maturity (presence of male copulate organ) and reproductive (presence of daughter) status of transmitting worms, in order to consider the factors that influence parasite option to migrate to a new individual of the same host species. This study demonstrates that parasites with a Male Copulate Organ (MCO) present are more likely to abandon the host and attempt a host transfer. The use of the anaesthetic 2-phenoxyethanol does not affect transmission of gyrodactylids which leave the host to colonise a new host. Finally, the use of other anaesthetic although its relative importance with respect to transmission remains uncertain.Department of the Environment, Food and Rural Affairs (Defra); Overseas Research Students Awards Scheme (ORSAS) UK; Consejo Nacional Ciencia y Tecnologia, Mexico CONACyT [171032]info:eu-repo/semantics/publishedVersio

Primera cita de Leptodactylus ocellatus (Linnaeus, 1758) (Amphibia, Anura, Leptodactylidae) en Bolivia y comentarios sobre especies próximas

The distributions of Leptodactylus ocellatus, L. chaquensis, and L. macrosternum in Bolivia are reviewed and discussed. Leptodactylus chaquensis and L. ocellatus are easily distinguished morphologically but L. chaquensis and L. macrosternum are indistinguishable. In Bolivia, L. ocellatus is known only from a single locality in the Paraguay River basin, which is reported here for the first time. Leptodactylus chaquensis occurs in the Chaco region of southeastern Bolivia, but it is unknown to what extent this species enters the Cerrado. The distribution boundaries and putative overlapping areas of L. chaquensis and L. macrosternum are unknown.Se revisa y discute la distribución de Leptodactylus ocellatus, L. chaquensis y L. macrosternum en Bolivia. Mientras que, morfológicamente, L. chaquensis y L. ocellatus se diferencian fácilmente, L. chaquensis y L. macrosternum son imposibles de distinguir. Leptodactylus ocellatus se encuentra en la parte boliviana de la cuenca del río Paraguay, aunque de momento se conoce solamente de una localidad, que se cita aquí por primera vez. Leptodactylus chaquensis habita en el Chaco, pero se deconoce hasta dónde penetra en el Cerrado. No se conocen los límites de las áreas de distribución y posibles zonas de solapamiento de L. chaquensis y L. macrosternum

Strain balanced quantum posts

Quantum posts are assembled by epitaxial growth of closely spaced quantum dot layers, modulating the composition of a semiconductor alloy, typically InGaAs. In contrast with most self-assembled nanostructures, the height of quantum posts can be controlled with nanometer precision, up to a maximum value limited by the accumulated stress due to the lattice mismatch. Here we present a strain compensation technique based on the controlled incorporation of phosphorous, which substantially increases the maximum attainable quantum post height. The luminescence from the resulting nanostructures presents giant linear polarization anisotropy.Comment: Submitted to Applied Physics Letters (7th March 2011). 4 pages, 4 figure

La detección de las diferencias psicológicas individuales de los españoles nativos y los inmigrantes de Marruecos, basándose las pruebas de control propioceptivo en el rendimiento motor fino

Background: Russian physiologists and psychologists posed the questions of the levels of psychic regulation of the temperament, character and personality (Anan’ev, 1980; Nebylitsin, 1966; Pavlov, 1951; Teplov, 1963). The aim of our study was to observe the differences due to both --- cultural nature and individual changes in personality --- relevant to adjustment mechanisms in Arabic migrants in Spain. Method: Proprioceptive Diagnostics of Temperament and Character (DP-TC, Tous Ral et al., 2012) was used to obtain observations in fine motor performance in two groups: immigrants from Morocco to Spain and Spaniards. The DP-TC of individual and personality differences is based on fine motor precision tasks and allows comparing performances of participants from different cultures with no bias of linguistic interpretation. Results: The significant differences in fine motor performance (proprioceptive condition) were found in average group’s results. The consequent interpretation of their personality and indi-vidual behavioural differences was realised as per the DP-TC test dimensions. The results are discussed in terms of the interplay between possible cultural and individual differences concerning changes, related to the adjustment in migration processes. Antecedentes: Los fisiólogos y psicólogos rusos plantearon las cuestiones de los niveles de regu-lación psíquica del temperamento, el carácter y la personalidad (Pavlov, 1951; Anan’ev, 1980;Teplov, 1966; Nebylitsin, 1966). El objetivo de nuestro estudio fue observar las diferenciasdebidas tanto a la naturaleza cultural como a los cambios individuales en la personalidad,relevantes en los mecanismos de ajuste en los migrantes.Método: Se utilizó el Diagnóstico Propioceptivo del Temperamento y del Carácter (DP-TC, Touset al., 2012) para obtener observaciones en el rendimiento motor fino en 2 grupos: inmigrantesde Marruecos a Espa˜na y espa˜noles. El DP-TC se basa en tareas de precisión motora fina y permitecomparar las actuaciones de participantes de diferentes culturas sin sesgo de interpretaciónlingüística.Resultados: Se encontraron las diferencias significativas en el rendimiento (condición pro-pioceptiva) según los resultados promedios de los grupos. Se realizó la correspondienteinterpretación de las diferencias en personalidad. Los resultados se discuten en términos de lainteracción entre las posibles diferencias culturales e individuales relacionadas con el ajusteen los procesos migratorios.Conclusión: Los rasgos de temperamento relacionados con la asertividad en los migrantes seencontraron bajos junto con diferencias culturales en variabilidad de comportamiento y estilode atención

Quasienergy spectrum and tunneling current in ac-driven triple quantum dot shuttles

The dynamics of electrons in ac driven double quantum dots have been extensively analyzed by means of Floquet theory. In these systems, coherent destruction of tunneling has been shown to occur for certain ac field parameters. In the present work we analyze, by means of Floquet theory, the electron dynamics of a triple quantum dot in series attached to electric contacts, where the central dot position oscillates. In particular, we analyze the quasienergy spectrum of this ac driven nanoelectromechanical system, as a function of the intensity and frequency of the ac field and of external dc voltages. For strong driving fields, we derive, by means of perturbation theory, analytical expressions for the quasienergies of the driven oscillator system. From this analysis we discuss the conditions for coherent destruction of tunneling (CDT) to occur as a function of detuning and field parameters. For zero detuning, and from the invariance of the Floquet Hamiltonian under a generalized parity transformation, we find analytical expressions describing the symmetry properties of the Fourier components of the Floquet states under such transformation. By using these expressions, we show that in the vicinity of the CDT condition, the quasienergy spectrum exhibits exact crossings which can be characterized by the parity properties of the corresponding eigenvectors

Efficient metallic spintronic emitters of ultrabroadband terahertz radiation

Terahertz electromagnetic radiation is extremely useful for numerous applications such as imaging and spectroscopy. Therefore, it is highly desirable to have an efficient table-top emitter covering the 1-to-30-THz window whilst being driven by a low-cost, low-power femtosecond laser oscillator. So far, all solid-state emitters solely exploit physics related to the electron charge and deliver emission spectra with substantial gaps. Here, we take advantage of the electron spin to realize a conceptually new terahertz source which relies on tailored fundamental spintronic and photonic phenomena in magnetic metal multilayers: ultrafast photo-induced spin currents, the inverse spin-Hall effect and a broadband Fabry-P\'erot resonance. Guided by an analytical model, such spintronic route offers unique possibilities for systematic optimization. We find that a 5.8-nm-thick W/CoFeB/Pt trilayer generates ultrashort pulses fully covering the 1-to-30-THz range. Our novel source outperforms laser-oscillator-driven emitters such as ZnTe(110) crystals in terms of bandwidth, terahertz-field amplitude, flexibility, scalability and cost.Comment: 18 pages, 10 figure

The HADES RV Programme with HARPS-N at TNG XI. GJ 685 b: a warm super-Earth around an active M dwarf

Small rocky planets seem to be very abundant around low-mass M-type stars. Their actual planetary population is however not yet precisely understood. Currently several surveys aim to expand the statistics with intensive detection campaigns, both photometric and spectroscopic. We analyse 106 spectroscopic HARPS-N observations of the active M0-type star GJ 685 taken over the past five years. We combine these data with photometric measurements from different observatories to accurately model the stellar rotation and disentangle its signals from genuine Doppler planetary signals in the RV data. We run an MCMC analysis on the RV and activity indexes time series to model the planetary and stellar signals present in the data, applying Gaussian Process regression technique to deal with the stellar activity signals. We identify three periodic signals in the RV time series, with periods of 9, 24, and 18 d. Combining the analyses of the photometry of the star with the activity indexes derived from the HARPS-N spectra, we identify the 18 d and 9 d signals as activity-related, corresponding to the stellar rotation period and its first harmonic respectively. The 24 d signals shows no relations with any activity proxy, so we identify it as a genuine planetary signal. We find the best-fit model describing the Doppler signal of the newly-found planet, GJ 685\,b, corresponding to an orbital period $P_b = 24.160^{+0.061}_{-0.047}$ d and a minimum mass $M_P \sin i = 9.0^{+1.7}_{-1.8}$ M$_\oplus$. We also study a sample of 70 RV-detected M-dwarf planets, and present new statistical evidence of a difference in mass distribution between the populations of single- and multi-planet systems, which can shed new light on the formation mechanisms of low-mass planets around late-type stars.Comment: 18 pages, 13 figures, accepted for publication in A&

HADES RV Programme with HARPS-N at TNG. VII. Rotation and activity of M-Dwarfs from time-series high-resolution spectroscopy of chromospheric indicators

We aim to investigate the presence of signatures of magnetic cycles and rotation on a sample of 71 early M-dwarfs from the HADES RV programme using high-resolution time-series spectroscopy of the Ca II H & K and Halpha chromospheric activity indicators, the radial velocity series, the parameters of the cross correlation function and the V-band photometry. We used mainly HARPS-N spectra, acquired over four years, and add HARPS spectra from the public ESO database and ASAS photometry light-curves as support data, extending the baseline of the observations of some stars up to 12 years. We provide log(R'hk) measurements for all the stars in the sample, cycle length measurements for 13 stars, rotation periods for 33 stars and we are able to measure the semi-amplitude of the radial velocity signal induced by rotation in 16 stars. We complement our work with previous results and confirm and refine the previously reported relationships between the mean level of chromospheric emission, measured by the log(R'hk), with the rotation period, and with the measured semi-amplitude of the activity induced radial velocity signal for early M-dwarfs. We searched for a possible relation between the measured rotation periods and the lengths of the magnetic cycle, finding a weak correlation between both quantities. Using previous v sin i measurements we estimated the inclinations of the star's poles to the line of sight for all the stars in the sample, and estimate the range of masses of the planets GJ 3998 b and c (2.5 - 4.9 Mearth and 6.3 - 12.5 Mearth), GJ 625 b (2.82 Mearth), GJ 3942 b (7.1 - 10.0 Mearth) and GJ 15A b (3.1 - 3.3 Mearth), assuming their orbits are coplanar with the stellar rotation.Comment: 19 pages, 16 figures, 10 table