Mapping the dynamic interactions between vortex species in highly anisotropic superconductors

Here we use highly sensitive magnetisation measurements performed using a Hall probe sensor on single crystals of highly anisotropic high temperature superconductors $Bi_{2}Sr_{2}CaCu_{2}O_{8}$ to study the dynamic interactions between the two species of vortices that exist in such superconductors. We observe a remarkable and clearly delineated high temperature regime that mirrors the underlying vortex phase diagram. Our results map out the parameter space over which these dynamic interaction processes can be used to create vortex ratchets, pumps and other fluxonic devices.Comment: 7 pages, 3 figures, to be published in Supercond. Sci. Techno

The Magellanic Stream and the density of coronal gas in the Galactic halo

The properties of the Magellanic Stream constrain the density of coronal gas in the distant Galactic halo. We show that motion through ambient gas can strongly heat Stream clouds, driving mass loss and causing evaporation. If the ambient gas density is too high, then evaporation occurs on unreasonably short timescales. Since heating dominates drag, tidal stripping appears to be responsible for producing the Stream. Requiring the survival of the cloud MS IV for 500 Myr sets an upper limit on the halo gas density n_H< 10^{-5} cm^{-3} at 50 kpc, roughly a factor of 10 lower than that estimated from the drag model of Moore & Davis (1994). Implications for models of the evolution of gas in galaxy halos are discussed.Comment: 4 pages, 1 figure, in press, ApJ

Spatial adiabatic passage in a realistic triple well structure

We investigate the evolution of an electron undergoing coherent tunneling via adiabatic passage (CTAP) using the solution of the one-dimensional Schroedinger equation in both space and time for a triple well potential. We find the eigenspectrum and complete time evolution for a range of different pulsing schemes. This also provides an example of a system that can be described with the tools from both quantum optics and condensed matter. We find that while the quantum optics description of the process captures most of the key physics, there are important effects that can only be correctly described by a more complete representation. This is an important point for applications such as quantum information processing or quantum control where it is common practice to use a reduced state space formulation of the quantum system in question.Comment: 10 pages, 12 figures (color online) - Published Versio

The K20 survey. III. Photometric and spectroscopic properties of the sample

The K20 survey is an ESO VLT optical and near-infrared spectroscopic survey aimed at obtaining spectral information and redshifts of a complete sample of about 550 objects to K_s\leq20.0 over two independent fields with a total area of 52 arcmin^2. In this paper we discuss the scientific motivation of such a survey, we describe the photometric and spectroscopic properties of the sample, and we release the $K_s$-band photometric catalog. Extensive simulations showed that the sample is photometrically highly complete to K_s=20. The observed galaxy counts and the R-K_s color distribution are consistent with literature results. We observed spectroscopically 94% of the sample, reaching a spectroscopic redshift identification completeness of 92% to K_s\leq20.0 for the observed targets, and of 87% for the whole sample (i.e. counting also the unobserved targets). Deep spectroscopy was complemented with multi-band deep imaging in order to derive tested and reliable photometric redshifts for the galaxies lacking spectroscopic redshifts. The results show a very good agreement between the spectroscopic and the photometric redshifts with =0.01 and with a dispersion of \sigma_{\Delta z}=0.09. Using both the spectroscopic and the photometric redshifts, we reached an overall redshift completeness of about 98%. The size of the sample, the redshift completeness, the availability of high quality photometric redshifts and multicolor spectral energy distributions make the K20 survey database one of the most complete samples available to date for constraining the currently competing scenarios of galaxy formation and for a variety of other galaxy evolution studies.Comment: 13 pages, 10 figures, to appear in Astronomy & Astrophysic

Reflections from behind the screen: avoiding therapeutic rupture when utilising reflecting teams

Parker, N., & O'Reilly, M. (2013). Reflections from behind the screen: avoiding therapeutic rupture when utilising reflecting teams. The Family Journal: Counseling for Couples and Families, 21(2), 170-179. https://doi.org/10.1177/1066480712466810. Copyright © 2013 SAGE. Reprinted by permission of SAGE Publications.Since Tom Andersen developed the use of reflecting teams to facilitate the progress and process of family therapy, little empirical evidence has emerged regarding their effectiveness or use in therapeutic practice. Reflecting teams are typically embraced by family therapists as a positive mechanism for enhancing practice and thus it is important that research explores how they are utilized. In this article, we draw upon videotaped data of naturally occurring family therapy from the United Kingdom. Using conversation analysis, we identified three performative actions related to interrupting the therapeutic conversation to consult with a reflecting team. We found that therapists had difficulty exiting therapy, that on some occasions exit was hindered, and that there were disturbances in feeding back the reflections of the team. By examining the use of teams in real practice, we were able to make a number of recommendations for practicing family therapists to facilitate the use of this valuable resource

First report of generalized face processing difficulties in möbius sequence.

Reverse simulation models of facial expression recognition suggest that we recognize the emotions of others by running implicit motor programmes responsible for the production of that expression. Previous work has tested this theory by examining facial expression recognition in participants with Möbius sequence, a condition characterized by congenital bilateral facial paralysis. However, a mixed pattern of findings has emerged, and it has not yet been tested whether these individuals can imagine facial expressions, a process also hypothesized to be underpinned by proprioceptive feedback from the face. We investigated this issue by examining expression recognition and imagery in six participants with Möbius sequence, and also carried out tests assessing facial identity and object recognition, as well as basic visual processing. While five of the six participants presented with expression recognition impairments, only one was impaired at the imagery of facial expressions. Further, five participants presented with other difficulties in the recognition of facial identity or objects, or in lower-level visual processing. We discuss the implications of our findings for the reverse simulation model, and suggest that facial identity recognition impairments may be more severe in the condition than has previously been noted

Experiences of youth justice: youth justice discourses and their multiple effects

Interventions within youth justice systems draw on a range of rationales and philosophies. Traditionally demarcated by a welfare/justice binary, the complex array of contemporary rationales meld different philosophies and practices, suggesting a mutability that gives this sphere a continued (re)productive and felt effect. While it may be increasingly difficult to ascertain which of these discourses is dominant in different jurisdictions in the UK, particular models of justice are perceived to be more prominent (Muncie, 2006). Traditionally it is assumed that Northern Ireland prioritises restoration, Wales prioritises rights, England priorities risk and Scotland welfare (McVie, 2011; Muncie, 2008, 2011). However, how these discourses are enacted in practice, how multiple and competing rationales circulate within them and most fundamentally how they are experienced by young people is less clear. This paper, based on research with young people who have experienced the full range of interventions in the youth justice system in Northern Ireland examines their narratives of ‘justice’. It considers how different discourses might influence the same intervention and how the deployment of multiple rationalities gives the experience of ‘justice’ its effect

The K20 survey. VI. The Distribution of the Stellar Masses in Galaxies up to z~2

We present a detailed analysis of the stellar mass content of galaxies up to z=2.5 in the K20 galaxy sample, that has a 92% spectroscopic completeness and a complete $UBVRIzJK_s$ multicolor coverage. We find that the M/L ratio decreases with redshift: in particular, the average M/L ratio of early type galaxies decreases with $z$, with a scatter that is indicative of a range of star--formation time-scales and redshift of formation. More important, the typical M/L of massive early type galaxies is larger than that of less massive ones, suggesting that their stellar population formed at higher z. The final K20 galaxy sample spans a range of stellar masses from M*=10^9Msun to M*=10^12Msun, with massive galaxies ($M*>10^11Msun) detected up to z~2. We compute the Galaxy Stellar Mass Function at various z, of which we observe only a mild evolution (i.e. by 20-30%) up to z~1. At z>1, the evolution of the GSMF appears to be much faster: at z~2, about 35% of the present day stellar mass in objects with M*~10^11Msun appear to have assembled. We also detect a change in the physical nature of the most massive galaxies, since at z>1 a population of massive star--forming galaxies progressively appears. We finally analyze our results in the framework of Lambda-CDM hierarchical models. First, we show that the large number of massive galaxies detected at high z does not violate any fundamental Lambda-CDM constraint based on the number of massive DM halos. Then, we compare our results with the predictions of renditions of both semianalytic and hydro-dynamical models, that range from severe underestimates to slight overestimates of the observed mass density at z<~2. We discuss how the differences among these models are due to the different implementation of the main physical processes. (Abridged)Comment: Accepted for publication on Astronomy & Astrophysic

The evolution of the luminosity functions in the FORS Deep Field from low to high redshift: I. The blue bands

We use the very deep and homogeneous I-band selected dataset of the FORS Deep Field (FDF) to trace the evolution of the luminosity function over the redshift range 0.5 < z < 5.0. We show that the FDF I-band selection down to I(AB)=26.8 misses of the order of 10 % of the galaxies that would be detected in a K-band selected survey with magnitude limit K(AB)=26.3 (like FIRES). Photometric redshifts for 5558 galaxies are estimated based on the photometry in 9 filters (U, B, Gunn g, R, I, SDSS z, J, K and a special filter centered at 834 nm). A comparison with 362 spectroscopic redshifts shows that the achieved accuracy of the photometric redshifts is (Delta z / (z_spec+1)) < 0.03 with only ~ 1 % outliers. This allows us to derive luminosity functions with a reliability similar to spectroscopic surveys. In addition, the luminosity functions can be traced to objects of lower luminosity which generally are not accessible to spectroscopy. We investigate the evolution of the luminosity functions evaluated in the restframe UV (1500 Angstroem and 2800 Angstroem), u', B, and g' bands. Comparison with results from the literature shows the reliability of the derived luminosity functions. Out to redshifts of z ~ 2.5 the data are consistent with a slope of the luminosity function approximately constant with redshift, at a value of -1.07 +- 0.04 in the UV (1500 Angstroem, 2800 Angstroem) as well as u', and -1.25 +- 0.03 in the blue (g', B). We do not see evidence for a very steep slope (alpha < -1.6) in the UV at z ~ 3.0 and z ~ 4.0 favoured by other authors. There may be a tendency for the faint-end slope to become shallower with increasing redshift but the effect is marginal. We find a brightening of M_star and a decrease of Phi_star with redshift for all analyzed wavelengths. [abridged]Comment: 30 pages, re-submitted to A&A after referee comments have been taken into account, full-resolution version available at http://www.usm.uni-muenchen.de/people/gabasch/publications/gabasch_lfblue.p