Current approaches to orthography instruction for spanish heritage learners: an analysis of intermediate and advanced textbooks

As it is well known, heritage learners of Spanish have an advantage on oral production and aural comprehension over L2 learners. However, due to their lack of formal instruction in Spanish, their linguistic weaknesses lie on their literacy skills (reading and writing). In terms of writing skills, students mainly struggle with orthography issues (accentuation and spelling) and larger literacy skills (e.g. developing a thesis or organizing ideas). However, there is an important gap in the literature regarding orthographic acquisition since most of the research in the field on focus on form instruction has predominantly been on grammar acquisition (Anderson, 2008; Montrul and Bowles, 2008; Potowski, 2005, among others). In fact, despite the increasing amount of textbooks addressed to this student population with an emphasis on the writing process, to my knowledge there has not been a study on the current approaches of Spanish heritage learners’ textbooks for orthography instruction. After analyzing four popular textbooks for Spanish heritage, it can be deduced that the lack of research on this area perpetuates the maintenance of traditional non-communicative explicit instruction of orthography through drills after an explicit explanation of the rules of both accentuation and spelling but new textbooks shed some light towards the implementation of focus on form teaching techniques commonly used in the L2 classroom such as input-output activities

A large scale extinction map of the Galactic Anticenter from 2MASS

We present a 127deg x 63deg extinction map of the Anticenter of the Galaxy, based on and colour excess maps from 2MASS. This 8001 square degree map with a resolution of 4 arcminutes is provided as online material. The colour excess ratio / is used to determine the power law index of the reddening law (\beta) for individual regions contained in the area (e.g. Orion, Perseus, Taurus, Auriga, Monoceros, Camelopardalis, Cassiopeia). On average we find a dominant value of \beta=1.8+-0.2 for the individual clouds, in agreement with the canonical value for the interstellar medium. We also show that there is an internal scatter of \beta values in these regions, and that in some areas more than one dominant \beta value is present. This indicates large scale variations in the dust properties. The analysis of the A_V values within individual regions shows a change in the slope of the column density distribution with distance. This can either be attributed to a change in the governing physical processes in molecular clouds on spatial scales of about 1pc or an A_V dilution with distance in our map.Comment: 18 pages, 29 Figures, 1 Table, Accepted for publication by MNRAS, A version with higher resolution figures can be found at http://astro.kent.ac.uk/~df

Stellar Magnetism and starspots: the implications for exoplanets

Stellar variability induce by starspots can hamper the detection of exoplanets and bias planet property estimations. These features can also be used to study star-planet interactions as well as inferring properties from the underlying stellar dynamo. However, typical techniques, such as ZDI, are not possible for most host-stars. We present a robust method based on spot modelling to map the surface of active star allowing us to statistically study the effects and interactions of stellar magnetism with transiting exoplanets. The method is applied to the active Kepler-9 star where we find small evidence for a possible interaction between planet and stellar magnetosphere which leads to a 2:1 resonance between the spot rotation and orbital period.Comment: 4 pages, 1 figure, to be published in the proceedings of IAUS 302: Magnetic Fields Throughout Stellar Evolutio

Two-Dimensional Line Strength Maps in Three Well-studied Early-Type Galaxies

Integral field spectroscopy has been obtained for the nuclear regions of 3 large, well-studied, early-type galaxies. From these spectra we have obtained line strength maps for about 20 absorption lines, mostly belonging to the Lick system. An extensive comparison with multi-lenslet spectroscopy shows that accurate kinematic maps can be obtained, and also reproducible line strength maps. Comparison with long-slit spectroscopy also produces good agreement. We show that Mg is enhanced with respect to Fe in the inner disk of one of the three galaxies studied, the Sombrero. [Mg/Fe] there is larger than in the rest of the bulge. The large values of Mg/Fe in the central disk are consistent with the centres of other early-type galaxies, and not with large disks, like the disk of our Galaxy, where [Mg/Fe] is approximately 0. We confirm with this observation a recent result of Worthey (1998) that Mg/Fe is determined by the central kinetic energy, or escape velocity, of the stars, only, and not by the formation time scale of the stars. A stellar population analysis using the models of Vazdekis et al. (1996) shows that our observed H gamma agrees well with what is predicted based on the other lines. Using the line strength of the Ca II IR triplet as an indicator of the abundance of Ca, we find that Ca follows Fe, and not Mg, in these galaxies. This is peculiar, given the fact that Ca is an alpha-element. Finally, by combining the results of this paper with those of Vazdekis et al. (1997) we find that the line strength gradients in the three galaxies are primarily caused by variations in metallicity.Comment: 23 pages, Latex, includes mn.sty, accepted for publication in Monthly Notices of the Royal Astronomical Societ

Optimization of optical data transmitters for 40-Gb/s lightwave systems using frequency resolved optical gating

The measurement technique of frequency resolved optical gating has been used to optimize the phase of a 40-GHz train of optical pulses generated using a continuous-wave laser gated with an external modulator. This technique will be vital for optimization of optical transmitters to be used in systems operating at 40 Gb/s and beyond, as standard measurement techniques will not suffice to optimize such high-speed systems

A detailed two-dimensional stellar population study of M32

We present Two-Dimensional Spectroscopy of the 9x12 arcsec^2 central region of M32 obtained with the 2D_FIS fibre spectrograph installed at the William Herschel Telescope. From these spectra line strength maps have been reconstructed for about 20 absorption lines, mostly belonging to the Lick system. We find good agreement with long-slit line strength profiles in the literature. In contrast with previous studies, indices were azimuthally averaged along continuum isophotes of M32. A remarkable result is that no gradients are presented in the spectral indices. So, we have fitted the mean values of each spectral index and central colours to the models of Vazdekis et al. (1996) and Worthey (1994), finding that an intermediate age (~4 Gyr) and metallicity similar to solar (Z=0.02) are the best fitted values for the innermost region of M32.Comment: accepted in MNRA

Search for radial velocity variations in eight M-dwarfs with NIRSPEC/Keck II

Context. Radial velocity (RV) measurements from near-infrared spectra have become a potentially powerful tool to search for planets around cool stars and sub-stellar objects. As part of a large survey to characterize M-dwarfs using NIRSPEC at Keck II, we obtained spectra of eight late M-dwarfs (spectral types M5.0-M8.0) during two or more observing epochs per target. These spectra were taken with intermediate spectral resolving powers (R \sim 20,000) in the J-band. Aims. We search for relative radial velocity variability in these late M-dwarfs and test the NIRSPEC capability of detecting short period brown dwarf and massive planetary companions around low-mass stars in the J-band (\approx 1.25 micron). Additionally, we reanalyzed the data of the M8-type star vB10 (one of our targets) presented in Zapatero Osorio et al. (2009), which were obtained with the same instrumentation as our data. Methods. [...] Results. For the entire M-dwarf sample, we do not find any evidence of relative RV variations induced by a short period brown dwarf or massive planetary companion. The typical RV precision of the measurements is between 180 and 300 m/s, which is sufficient to detect hot Neptunes around M-dwarfs. Also, we find that the spurious RV shift in Zapatero et al. (2009) of the star VB10 was caused by asymmetries in the instrumental profile between different observing epochs, which were not taken into account in their analysis.Comment: A&A, 7 pages, 5 figure