Motion of vortices in type II superconductors

The methods of formal asymptotics are used to examine the behaviour of a system of curvilinear vortices in a type II superconductor as the thickness of the vortex cores tends to zero. The vortices then appear as singularities in the field equation and are analagous to line vortices in inviscid hydrodynamics. A local analysis near each vortex core gives an equation of motion governing the evolution of these singularities

Loss of residues 119 – 136, including the first β-strand of human prion protein, generates an aggregation-competent partially “open” form

In prion replication, the cellular form of prion protein (PrPC) must undergo a full conformational transition to its disease-associated fibrillar form. Transmembrane forms of PrP have been implicated in this structural conversion. The cooperative unfolding of a structural core in PrPC presents a substantial energy barrier to prion formation, with membrane insertion and detachment of parts of PrP presenting a plausible route to its reduction. Here, we examined the removal of residues 119 - 136 of PrP, a region which includes the first β-strand and a substantial portion of the conserved hydrophobic region of PrP, a region which associates with the ER membrane, on the structure, stability and self-association of the folded domain of PrPC. We see an "open" native-like conformer with increased solvent exposure which fibrilises more readily than the native state. These data suggest a stepwise folding transition, which is initiated by the conformational switch to this "open" form of PrPC

Silk garments plus standard care compared with standard care for treating eczema in children: a randomised controlled, observer blind, pragmatic trial (CLOTHES Trial)

Background The role of clothing in the management of eczema (syn. atopic dermatitis, atopic eczema) is poorly understood. This trial evaluated the effectiveness and cost-effectiveness of silk garments (in addition to standard care) for the management of eczema in children with moderate to severe disease. Methods and findings This was a parallel group randomised controlled, observer-blind trial. Children aged 1 to 15 years with moderate to severe eczema were recruited from secondary care and the community in five UK centres. Participants were allocated using on-line randomisation (1:1) to standard care, or standard care plus silk garments; stratified by age and recruiting centre. Silk garments were worn for 6 months. Primary outcome (eczema severity) was assessed at baseline, 2, 4 and 6 months, by nurses blinded to treatment allocation using the Eczema Area and Severity Index (EASI), which was log-transformed for analysis (intention-to-treat analysis). Safety outcome: number of skin infections. Three hundred children were randomised (26th Nov 2013 to 5th May 2015): 42% girls, 79% white, mean age 5 years. Primary analysis included 282/300 (94%) children (n = 141 in each group). The garments were worn more often at night than in the day (median of 81% of nights (25th to 75th centile 57% to 96%) and 34% of days (25th to 75th centile 10% to 76%)). Geometric mean EASI scores at baseline, 2, 4 and 6 months were 9·2, 6·4, 5·8, 5·4 for silk clothing and 8·4, 6·6, 6·0, 5·4 for standard care. There was no evidence of any difference between the groups in EASI score averaged over all follow up visits adjusted for baseline EASI score, age and centre (adjusted ratio of geometric means: 0·95, 95% CI 0·85 to 1·07). This confidence interval is equivalent to a difference of -1·5 to 0·5 in the original EASI scale units which is not clinically important. Skin infections occurred in 36/142 (25%) and 39/141 (28%) for silk clothing and standard care respectively. Even if the small observed treatment effect was genuine, the incremental cost per QALY was £56,881 in the base case analysis from an NHS perspective, suggesting that silk garments are unlikely to be cost-effective within currently accepted thresholds. Main limitations: whilst minimising detection bias, use of an objective primary outcome may have underestimated treatment effects. Conclusions Silk clothing is unlikely to provide additional benefit over standard care in children with moderate to severe eczema

Roadmap on printable electronic materials for next-generation sensors

The dissemination of sensors is key to realizing a sustainable, ‘intelligent’ world, where everyday objects and environments are equipped with sensing capabilities to advance the sustainability and quality of our lives—e.g., via smart homes, smart cities, smart healthcare, smart logistics, Industry 4.0, and precision agriculture. The realization of the full potential of these applications critically depends on the availability of easy-to-make, low-cost sensor technologies. Sensors based on printable electronic materials offer the ideal platform: they can be fabricated through simple methods (e.g., printing and coating) and are compatible with high-throughput roll-to-roll processing. Moreover, printable electronic materials often allow the fabrication of sensors on flexible/stretchable/biodegradable substrates, thereby enabling the deployment of sensors in unconventional settings. Fulfilling the promise of printable electronic materials for sensing will require materials and device innovations to enhance their ability to transduce external stimuli—light, ionizing radiation, pressure, strain, force, temperature, gas, vapours, humidity, and other chemical and biological analytes. This Roadmap brings together the viewpoints of experts in various printable sensing materials—and devices thereof—to provide insights into the status and outlook of the field. Alongside recent materials and device innovations, the roadmap discusses the key outstanding challenges pertaining to each printable sensing technology. Finally, the Roadmap points to promising directions to overcome these challenges and thus enable ubiquitous sensing for a sustainable, ‘intelligent’ world

Quantification of Ecological Change Using Repeat Photography and Ground Based Lidar

Remote sensing techniques have long been useful in quantifying changes in ecosystems and the field of remote sensing is constantly evolving to better assess and describe changes, both spatially and temporally. In this thesis I explored the novel use of two remote sensing methods to quantify ecosystems; repeat photograph to describe change over time, and ground based lidar to describe change spatially. Using repeat photography, I assessed the effects of the removal of livestock in riparian systems at Hart Mountain National Antelope Refuge in southeastern Oregon, 23 years after the cessation of cattle grazing. I compared photos taken before grazing was ended with later retake photos. Two methods were used for this assessment: 1) a qualitative visual method comparing seven cover types and processes and 2) a new quantitative method of inserting digital line transects into photos. Results indicated that channel widths and eroding banks decreased in 64% and 73% of sites, respectively. I found a 90% decrease in the amount of bare soil (p<0.001) and a 63 % decrease in exposed channel (p<0.001) as, well as a significant increase in the cover of grasses/sedges/forbs (15% increase, p=0.037), rushes (389% increase, p=0.014) and willow (388% increase, P<0.001). I also assessed the accuracy of the new method of inserting digital line transects into photo pairs. An overall accuracy of 91% (kappa 83%) suggests digital line transects can be a useful tool for quantifying vegetation cover from photos. My results indicate that the removal of cattle can result in dramatic changes in riparian vegetation, even in semi-arid landscapes and without active restoration treatments. I used ground based lidar to quantify forest structure in a spatially explicit manner. The structural complexity of a forest has profound influences on its ecological functioning and overall health. The arrangement and amount of aboveground biomass are two important components of this structural complexity that influence the biodiversity in a forest ecosystem. In this paper, I explored and develop novel depth and openness metrics derived from single point ground-based lidar scans, which can quantify this complexity to a higher level of detail. Depth is a 3D, radial measure of the visible distance in all directions from a location (e.g., at the scanner origin). Openness is the percent of scan pulses in the near-omnidirectional view without a return,. To derive these metrics, I collected 243 scans at 27 forested stands in the Pacific Northwest region of the United States, representing a broad range of forest structure types. I created structural signatures using depth and openness for each stand and determined that our metrics could reliably differentiate forests. These metrics were compared to several traditional metrics: diameter at breast height (DBH), basal area, and diameter diversity index (DDI). The mean and variance in DBH of trees, basal area, and DDI of each stand were determined by generating isovists (polygons measuring visible space from a location) derived from point cloud cross sections. Interestingly, there was only weak to moderate correlation observed between depth or openness metrics when compared with the mean and variance in DBH, basal area, and DDI, suggesting that our new metrics (depth and openness) quantify a wider range of aspects of structure at the stand and plot level that are not captured by those traditional metrics. The proposed metrics can quantify forest structure at a high level of precision, reduce observer bias, and preserve a level of complexity lost in simple indices. The proposed metrics have great potential for quantifying change in forested systems, and describing habitat for organisms.Keywords: Riparian Restoration, Remote Sensing, Repeat Photography, Lidar, Research Natural Areas, Forest Structure, Cattle Impacts, Passive restoratio

Relationships between Satellite-Based Spectral Burned Ratios and Terrestrial Laser Scanning

Three-dimensional point data acquired by Terrestrial Lidar Scanning (TLS) is used as ground observation in comparisons with fire severity indices computed from Landsat satellite multi-temporal images through Google Earth Engine (GEE). Forest fires are measured by the extent and severity of fire. Current methods of assessing fire severity are limited to on-site visual inspection or the use of satellite and aerial images to quantify severity over larger areas. On the ground, assessment of fire severity is influenced by the observers&#8217; knowledge of the local ecosystem and ability to accurately assess several forest structure measurements. The objective of this study is to introduce TLS to validate spectral burned ratios obtained from Landsat images. The spectral change was obtained by an image compositing technique through GEE. The 32 plots were collected using TLS in Wood Buffalo National Park, Canada. TLS-generated 3D points were converted to voxels and the counted voxels were compared in four height strata. There was a negative linear relationship between spectral indices and counted voxels in the height strata between 1 to 5 m to produce R2 value of 0.45 and 0.47 for unburned plots and a non-linear relationship in the height strata between 0 to 0.5m for burned plots to produce R2 value of 0.56 and 0.59. Shrub or stand development was related with the spectral indices at unburned plots, and vegetation recovery in the ground surface was related at burned plots. As TLS systems become more cost efficient and portable, techniques used in this study will be useful to produce objective assessments of structure measurements for fire refugia and ecological response after a fire. TLS is especially useful for the quick ground assessments which are needed for forest fire applications

Restoration of Riparian Areas Following the Removal of Cattle in the Northwestern Great Basin

We assessed the effects of the elimination of livestock in riparian systems at Hart Mountain National Antelope Refuge in southeastern Oregon, 23 years after the removal of cattle grazing, using 64 photos taken before grazing was removed compared with later retake photos. Two methods were used for this assessment: (1) a qualitative visual method comparing seven cover types and processes and (2) a new quantitative method of inserting digital line transects into photos. Results indicated that channel widths and eroding banks decreased in 64 and 73 % of sites, respectively. We found a 90 % decrease in the amount of bare soil (P \u3c 0.001) and a 63 % decrease in exposed channel (P \u3c 0.001) as well as a significant increase in the cover of grasses/sedges/forbs (15 % increase, P = 0.037), rushes (389 % increase, P = 0.014), and willow (388 % increase, P \u3c 0.001). We also assessed the accuracy of the new method of inserting digital line transects into photo pairs. An overall accuracy of 91 % (kappa 83 %) suggests that digital line transects can be a useful tool for quantifying vegetation cover from photos. Our results indicate that the removal of cattle can result in dramatic changes in riparian vegetation, even in semi-arid landscapes and without replanting or other active restoration efforts

New Structural Complexity Metrics for Forests from Single Terrestrial Lidar Scans

We developed new measures of structural complexity using single point terrestrial laser scanning (TLS) point clouds. These metrics are depth, openness, and isovist. Depth is a three-dimensional, radial measure of the visible distance in all directions from plot center. Openness is the percent of scan pulses in the near-omnidirectional view without a return. Isovists are a measurement of the area visible from the scan location, a quantified measurement of the viewshed within the forest canopy. 243 scans were acquired in 27 forested stands in the Pacific Northwest region of the United States, in different ecoregions representing a broad gradient in structural complexity. All stands were designated natural areas with little to no human perturbations. We created “structural signatures” from depth and openness metrics that can be used to qualitatively visualize differences in forest structures and quantitively distinguish the structural composition of a forest at differing height strata. In most cases, the structural signatures of stands were effective at providing statistically significant metrics differentiating forests from various ecoregions and growth patterns. Isovists were less effective at differentiating between forested stands across multiple ecoregions, but they still quantify the ecological important metric of occlusion. These new metrics appear to capture the structural complexity of forests with a high level of precision and low observer bias and have great potential for quantifying structural change to forest ecosystems, quantifying effects of forest management activities, and describing habitat for organisms. Our measures of structure can be used to ground truth data obtained from aerial lidar to develop models estimating forest structure

Restoration of Riparian Areas Following the Removal of Cattle in the Northwestern Great Basin

We assessed the effects of the elimination of livestock in riparian systems at Hart Mountain National Antelope Refuge in southeastern Oregon, 23 years after the removal of cattle grazing, using 64 photos taken before grazing was removed compared with later retake photos. Two methods were used for this assessment: (1) a qualitative visual method comparing seven cover types and processes and (2) a new quantitative method of inserting digital line transects into photos. Results indicated that channel widths and eroding banks decreased in 64 and 73% of sites, respectively. We found a 90% decrease in the amount of bare soil (P<0.001) and a 63% decrease in exposed channel (P<0.001) as well as a significant increase in the cover of grasses/sedges/forbs (15% increase, P = 0.037), rushes (389% increase, P = 0.014), and willow (388% increase, P<0.001). We also assessed the accuracy of the new method of inserting digital line transects into photo pairs. An overall accuracy of 91% (kappa 83%) suggests that digital line transects can be a useful tool for quantifying vegetation cover from photos. Our results indicate that the removal of cattle can result in dramatic changes in riparian vegetation, even in semi-arid landscapes and without replanting or other active restoration efforts.Keywords: Hart Mountain, Cattle, Grazing, Riparian, Repeat photography, Passive restoratio