Language Practice and Study Abroad

The present study measures the impact that pragmatic intervention has when students are exposed to targeted language practice during a six-week study abroad programme in Buenos Aires, Argentina. The intervention had three goals. First, the researcher drew learners’ attention to language use and context through discussion about pragmatics and exposure to authentic input. Second, the intervention aimed at making students aware of the pragmatic norms of the target culture, including the appropriate use of communication strategies. The third and final goal was to afford the participants opportunities to engage in what DeKeyser (2007) and others argue are five critical aspects of language practice during study abroad: input, output, interaction, guided reflection and targeted feedback. Results indicated that over time all six students increased their use of targetlike request strategies. Journal entries and interviews with the researcher also revealed that the students became more aware of appropriate target-like request behaviour as a result of the language practice. In their journals and interviews, the students also attributed their pragmatic development to three additional sources: interactions with host families and other native speakers, their participation in service encounter exchanges and the targeted feedback given to them by the researcher. The results suggest that exposure to targeted language practice prior to and during study abroad can facilitate pragmatic learning and, in turn, contribute to a more successful study abroad experience

L2 Spanish apologies development during short-term study abroad

The present study examined the apologies of 18 study abroad (SA) students during a short-term SA experience in Madrid, Spain. Apologies were assessed with a discourse completion task (DCT) consisting of five vignettes that varied across three variables: relative social status of the interlocutor, relative social distance, and seriousness of the offense. Based on performance ratings assigned to them by two native Spanish speakers, the students made significant gains in pragmatic appropriateness from pretest to posttest, on two out of the five individual vignettes, and on the five combined vignettes. Examination of the students’ apologies before and after SA further revealed that they increased several strategies during their time abroad. Despite these gains, other aspects of the SA group’s performance remained the same or, in some cases, moved in the opposite direction of the target norm. Moreover, the students also demonstrated continued overreliance on routine, formulaic expressions on the posttest DCT while underusing some important target-like mitigation strategies. Given the study’s findings, the researcher offers recommendations for teaching pragmatics before and during the SA experience

On the additive manufacturing, post-tensioning and testing of bi-material tensegrity structures

An investigation on the additive manufacturing and the experimental testing of 3D models of tensegrity prisms and columns is presented. An Electron Beam Melting facility (Arcam EBM S12) is employed to 3D print structures composed of tensegrity prisms endowed with rigid bases and temporary supports, which are made out of the titanium alloy Ti6Al4V. The temporary supports are removed after the additive manufacturing phase, when Spectra cross-strings are added to the 3D printed models, and a suitable state of internal prestress is applied to the structure. The experimental part of the study shows that the examined structures feature stiffening-type elastic response under large or moderately large axial strains induced by compressive loading. Such a geometrically nonlinear behavior confirms previous theoretical results available in the literature, and paves the way to the use of tensegrity prisms and columns as innovative mechanical metamaterials and smart devices

Methods for Rapid Pore Classification in Metal Additive Manufacturing

The additive manufacturing of metals requires optimisation to find the melting conditions that give the desired material properties. A key aspect of the optimisation is minimising the porosity that forms during the melting process. A corresponding analysis of pores of different types (e.g. lack of fusion or keyholes) is therefore desirable. Knowing that pores form under different thermal conditions allows greater insight into the optimisation process. In this work, two pore classification methods were trialled: unsupervised machine learning and defined limits. These methods were applied to 3D pore data from X-ray computed tomography and 2D pore data from micrographs. Data were collected from multiple alloys (Ti-6Al-4V, Inconel 718, Ti-5553 and Haynes 282). Machine learning was found to be the most useful for 3D pore data and defined limits for the 2D pore data; the latter worked by optimising the limits using energy densities

The non-convex shape of (234) Barbara, the first Barbarian

Asteroid (234) Barbara is the prototype of a category of asteroids that has been shown to be extremely rich in refractory inclusions, the oldest material ever found in the Solar system. It exhibits several peculiar features, most notably its polarimetric behaviour. In recent years other objects sharing the same property (collectively known as ‘Barbarians') have been discovered. Interferometric observations in the mid-infrared with the ESO VLTI (Very Large Telescope Interferometer) suggested that (234) Barbara might have a bi-lobated shape or even a large companion satellite. We use a large set of 57 optical light curves acquired between 1979 and 2014, together with the timings of two stellar occultations in 2009, to determine the rotation period, spin-vector coordinates, and 3-D shape of (234) Barbara, using two different shape reconstruction algorithms. By using the light curves combined to the results obtained from stellar occultations, we are able to show that the shape of (234) Barbara exhibits large concave areas. Possible links of the shape to the polarimetric properties and the object evolution are discussed. We also show that VLTI data can be modelled without the presence of a satellit

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

A New Class of Luminous Transients and A First Census of Their Massive Stellar Progenitors

The progenitors of SN 2008S and the 2008 transient in NGC300 were dust-enshrouded, with extremely red mid-infrared (MIR) colors and relatively low luminosities. The transients were optically faint (-13 < M_V < -15) compared to normal core-collapse supernovae (SNe), and their spectra exhibited narrow emission lines. These events are unique among transient-progenitor pairs and hence constitute a new class. Whether they are true SNe or bright massive-star eruptions, we argue that their rate is ~20% of the SN rate. This fact is remarkable in light of the observation that a very small fraction of all massive stars have the MIR colors of the SN 2008S and NGC300 progenitors, as we show using MIR and optical luminosity, color, and variability properties of massive stars in M33. We find that the fraction of massive stars with colors consistent with these progenitors is 1/10000. In fact, only < 10 similar objects exist in M33 - all of which lie at the luminous red extremum of the AGB sequence. That these transients are relatively common with respect to SNe, while their progenitors are rare compared to the massive star population, implies that the dust-enshrouded phase is a short-lived phase in the lives of many massive stars. This shrouded epoch can occur only in the last ~10^4 yr before explosion, be it death or merely eruption. We discuss the implications of this finding for the evolution and census of ``low-mass'' massive stars (8-12 Msun), and we connect it with theoretical discussions of electron-capture SNe and the explosive birth of white dwarfs. A systematic census with (warm) Spitzer of galaxies in the local universe for analogous progenitors would significantly improve our knowledge of this channel to massive stellar explosions, and potentially to others with obscured progenitors. (Abridged)Comment: 24 pages; revised in response to referee's comments; conclusions unchanged, discussion update