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This article will outline the experience of researchers at De Montfort University (DMU) (Leicester, UK) in devising and delivering workshops on sound-based creativity (sbc). These workshops supported and guided participants through the process of listening training, recording and composing their own sound-based pieces. As well as engaging participants in sound-based composition, the aim of these workshops was to introduce them to examples from the repertoire of sbm. The final workshops involved the collection of Intention/Reception (I/R) data from participants in response to a piece of sbm. Nearly 180 participants from a diverse range of ages and backgrounds took part in the workshops and the data indicate that engagement with sbm was high. This article will provide the context for the project, describe the methodology and analyse and evaluate the data that were collected. Finally, the implications for future work will be discussed.
Ice scallops are a small-scale (5–20 cm) quasi-periodic ripple pattern that occurs at the ice–water interface. Previous work has suggested that scallops form due to a self-reinforcing interaction between an evolving ice-surface geometry, an adjacent turbulent flow field and the resulting differential melt rates that occur along the interface. In this study, we perform a series of laboratory experiments in a refrigerated flume to quantitatively investigate the mechanisms of scallop formation and evolution in high resolution. Using particle image velocimetry, we probe an evolving ice–water boundary layer at sub-millimetre scales and 15 Hz frequency. Our data reveal three distinct regimes of ice–water interface evolution: a transition from flat to scalloped ice; an equilibrium scallop geometry; and an adjusting scallop interface. We find that scalloped-ice geometry produces a clear modification to the ice–water boundary layer, characterized by a time-mean recirculating eddy feature that forms in the scallop trough. Our primary finding is that scallops form due to a self-reinforcing feedback between the ice-interface geometry and shear production of turbulent kinetic energy in the flow interior. The length of this shear production zone is therefore hypothesized to set the scallop wavelength.
Emergency medical teams (EMTs) have helped to provide surgical care in many recent sudden onset disasters (SODs), especially in low- and middle-income countries (LMICs). General surgical training in Australia has undergone considerable change in recent years, and it is not known whether the new generation of general surgeons is equipped with the broad surgical skills needed to operate as part of EMTs.
To analyze the differences between the procedures performed by contemporary Australian general surgeons during training and the procedures performed by EMTs responding to SODs in low- and middle-income countries (LMICs).
General surgical trainee logbooks between February 2008 and January 2017 were obtained from General Surgeons Australia. Operating theatre logs from EMTs working during the 2010 earthquake in Haiti, 2014 typhoon in the Philippines, and 2015 earthquake in Nepal were also obtained. These caseloads were collated and compared.
A total of 1,396,383 procedures were performed by Australian general surgical trainees in the study period. The most common procedure categories were abdominal wall hernia procedures (12.7%), cholecystectomy (11.7%), and specialist colorectal procedures (11.5%). Of note, Caesarean sections, hysterectomy, fracture repair, specialist neurosurgical, and specialist pediatric surgical procedures all made up <1% of procedures each. There were a total of 3,542 procedures recorded in the EMT case logs. The most common procedures were wound debridement (31.5%), other trauma (13.3%), and Caesarean section (12.5%). Specialist colorectal, hepato-pancreaticobiliary, upper gastrointestinal, urological, vascular, neurosurgical, and pediatric surgical procedures all made up <1% each.
Australian general surgical trainees get limited exposure to the obstetric, gynecological, and orthopedic procedures that are common during EMT responses to SODs. However, there is considerable exposure to the soft tissue wound management and abdominal procedures.
To describe the types of surgical procedures performed by emergency medical teams (EMTs) with general surgical capability in the aftermath of sudden-onset disasters (SODs) in low- and middle-income countries (LMICs).
A search of electronic databases (PubMed, MEDLINE, and EMBASE) was carried out to identify articles published between 1990 and 2018 that describe the type of surgical procedures performed by EMTs in the impact and post-impact phases a SOD. Further relevant articles were obtained by hand-searching reference lists.
16 articles met the inclusion criteria. Articles reporting on EMTs from a number of different countries and responding to a variety of disasters were included. There was a high prevalence of procedures for extremity soft tissue injuries (46.8%) and fractures (28.3%). However, a significant number of genitourinary/obstetric procedures were also reported.
Knowledge of the types of surgical procedures most frequently performed by EMTs may help further determine the necessary prerequisite surgical skills required for the recruitment of surgeons for EMTs. Experience in basic plastic, orthopedic, urological, and obstetric surgery would seem desirable for surgeons and surgical teams wishing to participate in an EMT.
Proglacial environments are ideal for studying the development of soils through the changes of rocks exposed by glacier retreat to weathering and microbial processes. Carbon (C) and nitrogen (N) contents as well as soil pH and soil elemental compositions are thought to be dominant factors structuring the bacterial, archaeal and fungal communities in the early stages of soil ecosystem formation. However, the functional linkages between C and N contents, soil composition and microbial community structures remain poorly understood. Here, we describe a multivariate analysis of geochemical properties and associated microbial community structures between a moraine and a glaciofluvial outwash in the proglacial area of a High Arctic glacier (Longyearbreen, Svalbard). Our results reveal distinct differences in developmental stages and heterogeneity between the moraine and the glaciofluvial outwash. We observed significant relationships between C and N contents, δ13Corg and δ15N isotopic ratios, weathering and microbial abundance and community structures. We suggest that the observed differences in microbial and geochemical parameters between the moraine and the glaciofluvial outwash are primarily a result of geomorphological variations of the proglacial terrain.
Lateral memristors consisting of planar Ag electrodes (with sub-micrometer separation) supported on thin films of amorphous zinc-tin-oxide have been characterized. After an initial filament-forming process, each device exhibited volatile, resistive switching. In the low resistance state, the transport mechanism and conductance depended on prior activity and on the imposed current limit, mimicking biologic synaptic plasticity. Microscopic observations performed on each device revealed nanoscale filaments between the electrodes. These filaments were subject to Rayleigh instability and exhibited relaxation times determined by their effective radii. The relaxation times and on:off resistance ratios suggest suitability for threshold switching selector devices.
Interaction of Greenland’s marine-terminating glaciers with the ocean has emerged as a key term in the ice-sheet mass balance and a plausible trigger for their recent acceleration. Our knowledge of the dynamics, however, is limited by scarcity of ocean measurements at the glacier/ocean boundary. Here data collected near six marine-terminating glaciers (79 North, Kangerdlugssuaq, Helheim and Petermann glaciers, Jakobshavn Isbræ, and the combined Sermeq Kujatdleq and Akangnardleq) are compared to investigate the water masses and the circulation at the ice/ocean boundary. Polar Water, of Arctic origin, and Atlantic Water, from the subtropical North Atlantic, are found near all the glaciers. Property analysis indicates melting by Atlantic Water (AW; found at the grounding line depth near all the glaciers) and the influence of subglacial discharge at depth in summer. AW temperatures near the glaciers range from 4.5˚C in the southeast, to 0.16˚C in northwest Greenland, consistent with the distance from the subtropical North Atlantic and cooling across the continental shelf. A review of its offshore variability suggests that AW temperature changes in the fjords will be largest in southern and smallest in northwest Greenland, consistent with the regional distribution of the recent glacier acceleration.
A numerical model for an interacting ice shelf and ocean is presented in which the ice- shelf base exhibits a channelized morphology similar to that observed beneath Petermann Gletscher’s (Greenland) floating ice shelf. Channels are initiated by irregularities in the ice along the grounding line and then enlarged by ocean melting. To a first approximation, spatially variable basal melting seaward of the grounding line acts as a steel-rule die or a stencil, imparting a channelized form to the ice base as it passes by. Ocean circulation in the region of high melt is inertial in the along-channel direction and geostrophically balanced in the transverse direction. Melt rates depend on the wavelength of imposed variations in ice thickness where it enters the shelf, with shorter wavelengths reducing overall melting. Petermann Gletscher’s narrow basal channels may therefore act to preserve the ice shelf against excessive melting. Overall melting in the model increases for a warming of the subsurface water. The same sensitivity holds for very slight cooling, but for cooling of a few tenths of a degree a reorganization of the spatial pattern of melting leads, surprisingly, to catastrophic thinning of the ice shelf 12 km from the grounding line. Subglacial discharge of fresh water along the grounding line increases overall melting. The eventual steady state depends on when discharge is initiated in the transient history of the ice, showing that multiple steady states of the coupled system exist in general.
The freezing of sea water to the base of an ice shelf can give rise to large patches of accumulated ice, a phenomenon known as marine ice. In this study a numerical method is presented for calculating the thickness of the marine-ice layer using an ice- shelf-ocean model. The present-day modeling paradigm of ice-shelf–ocean interaction usually involves the fixed specification of the ice-shelf geometry while the ocean circulation in the cavity beneath the ice shelf evolves freely. This approach relies on several assumptions, such as steady-state ice-shelf thickness and ice-shelf flow fields, in order to make reasonable quantitative estimates of the thermodynamic exchange processes occurring at the ice-shelf base. This paper discusses the impact of these and other assumptions on the estimation of the thickness of the marine-ice layer. Model simulation results are presented for an idealized ice-shelf–ocean configuration as a demonstration of the feasibility of the numerical method. A sensitivity analysis is given so as to quantify the relative uncertainty in the marine-ice thickness that arises from uncertainties in the model input parameters, these being principally the ice-shelf flow field, the basal accumulation rate and the ice-shelf thickness field.
We used a terrestrial radar interferometer (TRI) at Helheim Glacier, Greenland, in August 2013, to study the effects of tidal forcing on the terminal zone of this tidewater glacier. During our study period, the glacier velocity was up to 25 m d–1. Our measurements show that the glacier moves out of phase with the semi-diurnal tides and the densely packed melange in the fjord. Here detrended glacier displacement lags behind the forecasted tidal height by ∼8 hours. The transition in phase lag between the glacier and the melange happens within a narrow (∼500 m) zone in the fjord in front of the ice cliff. The TRI data also suggest that the impact of tidal forcing decreases rapidly up-glacier of the terminus. A flowline model suggests this pattern of velocity perturbation is consistent with weak ice flowing over a weakly nonlinear bed.
Outlet glaciers undergo rapid spatial and temporal changes in flow velocity during calving events. Observing such changes requires both high temporal and high spatial resolution methods, something now possible with terrestrial radar interferometry. While a single such radar provides line-of-sight velocity, two radars define both components of the horizontal flow field. To assess the feasibility of obtaining the two-dimensional (2-D) flow field, we deployed two terrestrial radar interferometers at Jakobshavn Isbrae, a major outlet glacier on Greenland's west coast, in the summer of 2012. Here, we develop and demonstrate a method to combine the line-of-sight velocity data from two synchronized radars to produce a 2-D velocity field from a single (3 min) interferogram. Results are compared with the more traditional feature-tracking data obtained from the same radar, averaged over a longer period. We demonstrate the potential and limitations of this new dual-radar approach for obtaining high spatial and temporal resolution 2-D velocity fields at outlet glaciers.
The Advanced Camera for Surveys (ACS) offers a coronagraphic imaging mode with angular resolution of 0.026″pixel−1. In combination with with the appropriate subtraction of reference star point spread functions (PSF) the coronagraph is capable of achieving contrast ratios of ∼1000. We present some of the first ACS observations of the optically thin debris disk HD141569A and discuss new results from these observations.
Results are most complete for NGC 185–1, where the electron temperature is 17,900±1600°K. Compared to typical galactic planetary nebulae the abundance ratio in NGC 185–1 of helium/hydrogen (0.24±0.08) is approximately twice that normally found, the abundance ratio of oxygen/hydrogen (7.7±1.3)10−5 is approximately one-tenth that normally found, and the ratio of nitrogen/hydrogen (1.4 × 10−4, poorly known) is approximately equal to that normally found.
Time-varying elevations near the calving front of Jakobshavn Isbræ, Greenland were observed with a terrestrial radar interferometer (TRI) in June 2015. An ice block with surface dimensions of 1370 m × 290 m calved on 10 June. TRI-generated time series show that ice elevation near the calving front began to increase 65 h prior to the event, and can be fit with a simple block rotation model. We hypothesize that subsurface melting at the base of the floating terminus breaks the gravity-buoyancy equilibrium, leading to slow subsidence and rotation of the block, and its eventual failure.