A small collection of bryophytes from Montserrat, West Indies

Four species of liverworts and 13 taxa of mosses have been identified from samples collected in Montserrat in 1980, 11 of which appear to be new to the island

Chemical effects in ion mixing of a ternary system (metal-SiO_2)

The mixing of Ti, Cr, and Ni thin films with SiO_2 by low‐temperature (−196–25 °C) irradiation with 290 keV Xe has been investigated. Comparison of the morphology of the intermixed region and the dose dependences of net metal transport into SiO_2 reveals that long range motion and phase formation probably occur as separate and sequential processes. Kinetic limitations suppress chemical effects in these systems during the initial transport process. Chemical interactions influence the subsequent phase formation

Effect of dose rate on ion beam mixing in Nb-Si

The influence of dose rate, i.e., ion flux, on ion beam mixing in Nb‐Si bilayer samples was measured at room temperature and 325 °C. At the higher temperature, an increase in dose rate of a factor of 20 caused a decrease in the thickness of the mixed layer by a factor of 1.6 for equal total doses. At room temperature, the same change in flux had no effect on mixing. These results are consistent with radiation‐enhanced diffusion theory in the recombination‐limited regime

Ink and Identities: The politics of bodies and borders in 'Sin nombre'

Sin nombre, released in 2009, was the debut feature film by its director Cary Fukunaga. The film presents Fukunaga’s view of the migrant experience, taking the viewer on a journey from Honduras through Mexico and finally to the Mexico–US border. Against this backdrop, the human drama of an unrequited love story unfolds between the two protagonists around whom the film’s plot revolves. The questions of migration and of the crossing of cartographical and territorial borders, in this case those that mark the boundaries between Guatemala and Mexico, and Mexico and the US, are unavoidably prominent given the film’s subject matter, but there are other borders and boundaries of interest in this text that have not received so much attention. Whilst the migrant journey primarily concerns the movement of bodies across and between contested national territories, these liminal border zones also bear witness to changes in the bodies themselves: boundaries are crossed in this film not only in political but also bodily terms. The main expression of this in Sin nombre is the high visibility of tattooed bodies. They display signs of belonging and apartness, depending on which side of the border between social groups an individual is located. Bodies, as well as borders, are marked and regulated; the violation of codes and territories has potentially fatal consequences

Antarctic surface hydrology and impacts on ice-sheet mass balance

Melting is pervasive along the ice surrounding Antarctica. On the surface of the grounded ice sheet and floating ice shelves, extensive networks of lakes, streams and rivers both store and transport water. As melting increases with a warming climate, the surface hydrology of Antarctica in some regions could resemble Greenland’s present-day ablation and percolation zones. Drawing on observations of widespread Antarctica surface water and decades of study in Greenland, we consider three modes by which meltwater could impact Antarctic mass balance: increased runoff, meltwater injection to the bed, and meltwater-induced ice-shelf fracture, all of which may contribute to future ice sheet mass loss from Antarctica

Regulation of the human p21((waf1/cip1)) gene promoter via multiple binding sites for p53 and the vitamin D(3) receptor

The main regulator of the human tumor suppresser gene p21((waf1/cip1)) is the transcription factor p53, but more recently it has been suggested to be a primary anti-proliferative target for the nuclear receptor VDR in the presence of its ligand 1α,25-dihydroxyvitamin D(3) (1α,25(OH)(2)D(3)). To identify VDR responding regions, we analyzed 20 overlapping regions covering the first 7.1 kb of the p21((waf1/cip1)) promoter in MCF-7 human breast cancer cells using chromatin immuno-precipitation assays (ChIP) with antibodies against p53 and VDR. We confirmed two known p53 binding regions at approximate positions −1400 and −2300 and identified a novel site at position −4500. In addition, we found three VDR-associated promoter regions at positions −2300, −4500 and −6900, i.e. two regions showed binding for both p53 and VDR. In silico screening and in vitro binding assays using recombinant and in vitro translated proteins identified five p53 binding sites within the three p53-positive promoter regions and also five 1α,25(OH)(2)D(3) response elements within the three VDR-positive regions. Reporter gene assays confirmed the expected responsiveness of the respective promoter regions to the p53 inducer 5-fluorouracil and 1α,25(OH)(2)D(3). Moreover, re-ChIP assays confirmed the functionality of the three 1α,25(OH)(2)D(3)-reponsive promoter regions by monitoring simultaneous occupancy of VDR with the co-activator proteins CBP, SRC-1 and TRAP220. Taken together, we demonstrated that the human p21((waf1/cip1)) gene is a primary 1α,25(OH)(2)D(3)-responding gene with at least three VDR binding promoter regions, in two of which also p53 co-localizes

Broadband characterisation of in-duct acoustic sources using an equivalent source approach

This paper is concerned with the development of an experimental method capable of independently characterising low Mach number, in-duct fluid machines, such as pumps, fans, etc. The aim is to propose and test a source characterisation method that is suitable for acoustic simulation and the construction Virtual Acoustic Prototypes. Such a requirement demands that the source characterisation be (a) independent, so that components can be virtually (re)combined within different assemblies and (b) valid over a wide frequency range so as to enable the output of a virtual assembly to be auralised. In this regard, standard methods based on sound power are not suitable. An equivalent source approach is proposed, based on a two-stage measurement procedure in which source strengths are obtained by solving an inverse problem. The experimental application of the procedure is illustrated as part of a case study where a high speed compressor unit is independently characterised and the resulting source data used to predict the operational response in a new assembly. Three frequency ranges are identified based on plane wave, modal and statistical behavior within the duct. The same measured data is used within each regime but subject to different processing according to different assumptions. Predictions are shown to be in good agreement with the directly measured response over a broad frequency range (100 Hz–10 kHz)

Painting the ideal home: using art to express visions of technologically supported independent living for older people in North East England

This paper describes the investigation of the development of future technological products to support older people in everyday living through the agency of a community art group. Recent research has identified a number of challenges facing designers seeking to use traditional participatory design approaches to gather technology requirements data from older people. Here, a project is described that sought to get a group of older people to think creatively about their needs and desires for technological support through the medium of paint. The artistic expression technique described in this article allowed the identification of issues that had also been found by previous research that used a range of different techniques. This indicates that the approach shows promise, as it allows information to be gathered in an environment that is comfortable and familiar using methods already known by the participants and which they find enjoyable. It provides a complement (or possible alternative) to standard protocols and has the potential benefit of extracting even richer information as the primary task for participants is enjoyable in its own right and is not associated with an interrogative process. Furthermore, it is argued that some of the key risks of traditional approaches are lessened or removed by the naturalistic setting of this approach

Direct measurements of ice-shelf flexure caused by surface meltwater ponding and drainage.

Global sea-level rise is caused, in part, by more rapid ice discharge from Antarctica, following the removal of the restraining forces of floating ice-shelves after their break-up. A trigger of ice-shelf break-up is thought to be stress variations associated with surface meltwater ponding and drainage, causing flexure and fracture. But until now, there have been no direct measurements of these processes. Here, we present field data from the McMurdo Ice Shelf, Antarctica, showing that the filling, to ~2 m depth, and subsequent draining, by overflow and channel incision, of four surface lakes causes pronounced and immediate ice-shelf flexure over multiple-week timescales. The magnitude of the vertical ice-shelf deflection reaches maxima of ~1 m at the lake centres, declining to zero at distances of <500 m. Our results should be used to guide development of continent-wide ice-sheet models, which currently do not simulate ice-shelf break-up due to meltwater loading and unloading.This work was supported by the U.S. National Science Foundation under award PLR-1443126 to the University of Chicago, a Leverhulme Early Career Fellowship (ECF-2014-412) and a CIRES Postdoctoral Visiting Fellowship, both awarded to A.F.B., and a NASA Earth and Space Science Fellowship (NNX15AN44H) awarded to G.J.M