Comparison of BES measurements of ion-scale turbulence with direct, gyrokinetic simulations of MAST L-mode plasmas

Observations of ion-scale (k_y*rho_i <= 1) density turbulence of relative amplitude dn_e/n_e <= 0.2% are available on the Mega Amp Spherical Tokamak (MAST) using a 2D (8 radial x 4 poloidal channel) imaging Beam Emission Spectroscopy (BES) diagnostic. Spatial and temporal characteristics of this turbulence, i.e., amplitudes, correlation times, radial and perpendicular correlation lengths and apparent phase velocities of the density contours, are determined by means of correlation analysis. For a low-density, L-mode discharge with strong equilibrium flow shear exhibiting an internal transport barrier (ITB) in the ion channel, the observed turbulence characteristics are compared with synthetic density turbulence data generated from global, non-linear, gyro-kinetic simulations using the particle-in-cell (PIC) code NEMORB. This validation exercise highlights the need to include increasingly sophisticated physics, e.g., kinetic treatment of trapped electrons, equilibrium flow shear and collisions, to reproduce most of the characteristics of the observed turbulence. Even so, significant discrepancies remain: an underprediction by the simulations of the turbulence amplituide and heat flux at plasma periphery and the finding that the correlation times of the numerically simulated turbulence are typically two orders of magnitude longer than those measured in MAST. Comparison of these correlation times with various linear timescales suggests that, while the measured turbulence is strong and may be `critically balanced', the simulated turbulence is weak.Comment: 27 pages, 11 figure

Interview with Thomas Roach III, Willie George Hall, and Donald Parrish - OH 544

In this June 6, 2017 interview with Alex Windham, Thomas Roach II, Willie George Hall and Donald Parrish detail their thoughts and memories of their time at the Rock Hill Printing and Finishing Company referred to by locals as the “Bleachery.” They spoke at length about race relations at the Bleachery.https://digitalcommons.winthrop.edu/oralhistoryprogram/1621/thumbnail.jp

Estimating the sea ice floe size distribution using satellite altimetry: Theory, climatology, and model comparison

In sea-ice-covered areas, the sea ice floe size distribution (FSD) plays an important role in many processes affecting the coupled sea-ice-ocean-atmosphere system. Observations of the FSD are sparse - traditionally taken via a painstaking analysis of ice surface photography - and the seasonal and inter-annual evolution of floe size regionally and globally is largely unknown. Frequently, measured FSDs are assessed using a single number, the scaling exponent of the closest power-law fit to the observed floe size data, although in the absence of adequate datasets there have been limited tests of this "power-law hypothesis". Here we derive and explain a mathematical technique for deriving statistics of the sea ice FSD from polar-orbiting altimeters, satellites with sub-daily return times to polar regions with high along-track resolutions. Applied to the CryoSat-2 radar altimetric record, covering the period from 2010 to 2018, and incorporating 11 million individual floe samples, we produce the first pan-Arctic climatology and seasonal cycle of sea ice floe size statistics. We then perform the first pan-Arctic test of the power-law hypothesis, finding limited support in the range of floe sizes typically analyzed in photographic observational studies. We compare the seasonal variability in observed floe size to fully coupled climate model simulations including a prognostic floe size and thickness distribution and coupled wave model, finding good agreement in regions where modeled ocean surface waves cause sea ice fracture

Diversity and distribution of epiphytic bryophytes on Bramley's Seedling trees in East of England apple orchards.

© 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)Epiphytic bryophytes on apple trees were investigated in relation to a selection of tree characteristics. Management of orchard trees for fruit production affects the habitats available for colonisation and growth of epiphytes on trunks and branches. Bryophytes recorded on Bramley’s Seedling apple trees in orchards in Hertfordshire and Cambridgeshire showed a high level of similarity in species composition between the orchards. The similarity between orchards was, however, much reduced when relative species cover on the trees was taken into account. Twenty three species were recorded on the 71 trees sampled for detailed investigation. Tree structure, as determined by management, explained about 10% of the observed variation in bryophyte cover. Within that, trunk girth and distance to nearest neighbouring orchard trees were the most important factors. This information is of value to orchard managers aiming to become more proactive in managing their habitats for the benefit of biodiversityPeer reviewedFinal Published versio

Residual spinal cord compression following hemilaminectomy and mini-hemilaminectomy in dogs:a prospective randomized study

The aim of this study was to compare the reduction of spinal cord compression after surgical treatment of dogs with acute thoracolumbar intervertebral disc (IVD) extrusion achieved using hemilaminectomy versus mini-hemilaminectomy techniques. This was a prospective randomized study with client-owned dogs presented with acute IVD extrusion that were allocated to surgical treatment using hemilaminectomy (n = 15) or mini-hemilaminectomy (n = 15) techniques. Plain and intravenous-contrast computed tomography was performed pre- and postoperatively. The preoperative minimal cross-sectional dimension of the spinal cord (MDSC(pre)) and the postoperative minimal cross-sectional dimension of the spinal cord (MDSC(post)) were measured at the level of greatest compression. The minimal diameter of the uncompressed spinal cord was measured in a similar way both pre- (MDUSC(pre)) and postoperatively (MDUSC(post)). Dogs in the mini-hemilaminectomy group had significantly greater reduction of compression (RC) (p < 0.01) after surgery compared to dogs in the hemilaminectomy group. The mean RC in the hemilaminectomy group was 34.6% and in the mini-hemilaminectomy group 62.6%. Our results showed a significantly greater reduction of spinal cord compression for mini-hemilaminectomy compared to hemilaminectomy. Additionally, mini-hemilaminectomy could be a preferred method due to its minimal invasiveness and easier access to lateral fenestration

Recommended Guanidine Suppressor for the Next-Generation Caustic-Side Solvent Extraction Process

The guanidine recommended for the Next-Generation Caustic-Side is N,N ,N -tris(3,7-dimethyloctyl)guanidine (TiDG). Systematic testing has shown that it is significantly more lipophilic than the previously recommended guanidine DCiTG, the active extractant in the commercial guanidine product LIX -79, while not otherwise changing the solvent performance. Previous testing indicated that the extent of partitioning of the DCiTG suppressor to the aqueous strip solution is significantly greater than expected, potentially leading to rapid depletion of the suppressor from the solvent and unwanted organic concentrations in process effluents. Five candidate guanidines were tested as potential replacements for DCiTG. The tests included batch extraction with simulated waste and flowsheet solutions, third-phase formation, emulsion formation, and partition ratios of the guanidine between the solvent and aqueous strip solution. Preliminary results of a thermal stability test of the TiDG solvent at one month duration indicated performance approximately equivalent to DCiTG. Two of the guanidines proved adequate in all respects, and the choice of TiDG was deemed slightly preferable vs the next best guanidine BiTABG

Adults with dyslexia can use cues to orient and constrain attention but have a smaller and weaker attention spotlight

We report results from two experiments assessing distribution of attention and cue use in adults with dyslexia (AwD) and in a group of typically reading controls. Experiment 1 showed normal effects of cueing in AwD, with faster responses when probes were presented within a cued area and normal effects of eccentricity and stimulus onset asynchrony (SOA). In addition, AwD showed stronger benefits of a longer SOA when they had to move attention farther, and stronger effects of inclusion on the left, suggesting that cueing is particularly important in more difficult conditions. Experiment 2 tested the use of cues in a texture detection task involving a wider range of eccentricities and a shorter SOA. In this paradigm, focused attention at the central location is actually detrimental and cueing further reduces performance. Thus, if AwD have a more distributed attention, they should show a reduced performance drop at central locations and, if they do not use cues, they should show less negative effects of cueing. In contrast, AwD showed a larger drop and a positive effect of cueing. These results are better accounted for by a smaller and weaker spotlight of attention. Performance does not decrease at central locations because the attentional spotlight is already deployed with maximum intensity, which cannot be further enhanced at central locations. Instead, use of cueing helps to focus limited resources. Cues orient attention to the right area without enhancing it to the point where this is detrimental for texture detection. Implications for reading are discussed

Factor structure and validity of the shoulder pain and disability index in a population-based study of people with shoulder symptoms

Background: The Shoulder Pain and Disability Index (SPADI) is a self-administered questionnaire that aims to measure pain and disability associated with shoulder disease. The aim of the present study was to investigate the construct validity and factor structure of the SPADI in a population-based study of patients with self-reported chronic shoulder symptoms. Methods: The North West Adelaide Health Study is a representative longitudinal cohort study of people aged 18 years and over. The original sample was randomly selected and recruited by telephone interview. Overall, 3 206 participants returned to the clinic during the second stage (2004-2006) and were asked to report whether they had pain, aching or stiffness on most days in either of their shoulders. Data was also collected on body mass index and shoulder range of motion (ROM) and demographic factors. The SPADI (numeric rating scale) was administered to participants with shoulder symptoms. Principal components factor analysis, with varimax rotation of factor loadings, was used to assess subscale structure of SPADI. Correlations between the SPADI, shoulder ROM and SF-36 were performed. Results: Overall, 22.3% of participants indicated that they had pain, aching or stiffness in either of their shoulders. SPADI results were available for 588 of participants with current shoulder symptoms. The internal consistency of the SPADI subscales were high (Cronbach's alpha > 0.92). Two factors, explaining 61.4% of the total variance were extracted by factor analysis. These were interpreted as disability and pain respectively. There was a strong negative correlation between SPADI disability subscale scores and shoulder range of motion. SPADI disability, but not pain, subscale scores were correlated with age. Conclusions: The SPADI is a valid measure to assess pain and disability in people with shoulder pain in a population-based study. In this setting, the SPADI had a bidimensional structure with both pain and disability subscales.Catherine L Hill, Susan Lester, Anne W Taylor, Michael E Shanahan, Tiffany K Gil