Corpus annotation as a scientific task

Annotation studies in CL are generally unscientific: they are mostly not reproducible, make use of too few (and often non-independent) annotators and use guidelines that are often something of a moving target. Additionally, the notion of ‘expert annotators’ invariably means only that the annotators have linguistic training. While this can be acceptable in some special contexts, it is often far from ideal. This is particularly the case when subtle judgements are required or when, as increasingly, one is making use of corpora originating from technical texts that have been produced by, and intended to be consumed by, an audience of technical experts in the field. We outline a more rigorous approach to collecting human annotations, using as our example a study designed to capture judgements on the meaning of hedge words in medical records

Evaluating the Potential Effects of Deicing Salts on Roadside Carbon Sequestration

This project sought to document patterns of road deicing salts and the effects of these salts on the amount of carbon being sequestered passively along Montana Department of Transportation roads; it was designed collaboratively with a related roadside project that tested three different highway right-of-way management techniques (mowing height, shrub planting, disturbance) to determine whether they have the capacity to increase soil organic carbon. Our sampling did not reveal elevated salt levels at any of the nine locations sampled at each of the three I-90 sites. The greatest saline concentrations were found at the sample locations farthest from the road. This pattern was consistent across all three sites. The range of soil organic matter (SOM) was broad, from ~1% to >10%. Generally, SOM values were lowest adjacent to the road and highest farthest from the road. We found no or weak evidence of a relationship between our indices of soil salinity and SOM levels, with electrical conductivity, exchangeable calcium, and cation exchange capacity. Results imply that if road deicing salts are altering patterns of roadside SOM and potential carbon sequestration, this effect was not captured by our experimental design, nor did deicing salts appear to have affected roadside vegetation during our most recent sampling effort. Our findings highlight the value of experimentally separating the multiple potentially confounding effects of winter maintenance operations on roadside soils: roads could focus the flow of water, salts, and sands to roadside soils. How these types of mass inputs to roadside soils might influence medium- or long-term carbon dynamics remains an open question, but their fuller characterization and possible flow paths will be essential to clarifying the role of roadside soils in terrestrial soil organic carbon sequestration strategies

A Predictive Model for Convective Flows Induced by Surface Reactivity Contrast

Concentration gradients in a fluid along a reactive surface due to contrast in surface reactivity generate convective flows. These flows result from contributions by electro and diffusio osmotic phenomena. In this study we have analyzed reactive patterns that release and consume protons, analogous to bimetallic catalytic conversion of peroxide. Here, we present a simple analytical model that accurately predicts the induced potentials and consequent velocities in such systems over a wide range of input parameters. Our model is tested against direct numerical solutions to the coupled Poisson, Nernst-Planck, and Navier-Stokes equations. Our analysis can be used to predict enhancement of mass transport and the resulting impact on overall catalytic conversion, and is also applicable to predicting the speed of catalytic nanomotors

Snow Cover in Alaska: Comprehensive Review

This report presents the results of a statistical analysis of snow cover in Alaska using historical data acquired from the Global Historical Climate Network. Measurements of snow depth and snow water equivalence were collected for Alaska stations between 1950 and 2017. Data cleaning and a distribution analysis were completed for all stations. Finally regression equations were developed to estimate snow water equivalence using recorded snow depth data from Alaska stations. The project is partially supported by ConocoPhillips Arctic Science and Engineering Foundation, UAA, and the Structural Engineers Association of Alaska (SEAAK).University of Alaska Anchorage ConocoPhillips Arctic Science and Engineering Foundation Structural Engineers Association of AlaskaAbstract / Introduction / Methodology / Discussion / Conclusion / References / Appendix 1 Predicted 50-year WESD Stations's snow laods / Appendix 2 Calcuated 50-Year SNWD Station's snow loads / Appendix 3 Distribution Assignment for WESD and SNWD Stations / Appendix 4 Station Plot

Rhythms of the heart: The history of electrophysiology and its current status in South Africa

The foundations of cardiac electrophysiology were laid in the 19th and 20th century by the elucidation of the anatomy and physiology of the conduction system and cardiac muscle. The development of the ECG by Einthoven in the early 1900s has been the basis for its clinical application and remains the most important tool for diagnosis of arrhythmias. Invasive electrophysiological studies have refi ned and added to this understanding and led to the development of catheter ablation of cardiac arrhythmias. The invention of pacemakers and implantable cardioverter defi brillators (ICDs) has revolutionised the treatment of patients with brady and tachyarrhythmias. Despite these advances, catheter ablation, pacemakers and ICDs are unavailable to the majority of patients living in sub-Saharan Africa. In South Africa, there is a paucity of electrophysiologists in the academic/public sector as almost all electrophysiologists serve patients with private health insurance

Beneath the Baselines: Detecting Molecular Emission from Submillimeter Galaxies with the GBT

We report the first detection of a submillimeter galaxy (SMG) in CO(1 →0) emission using the GBT. We identify a line with Δv_(FWHM) ~1000 kms^(−1) in the 1 cm spectrum of SMM J13120+4242 at z = 3.408, which is significantly greater than the width of the previously detected CO(4→3) line. If the observed CO(1→0) line profile arises from a single object and not several merging objects, the CO(4 →3)/CO(1→0) brightness temperature ratio of ~0.26 suggests n(H_2) > 10^3 cm^(−3) and the presence of sub-thermally excited gas. The 10σ integrated line flux implies a cold molecular gas mass M(H2) ~10^(11)M_⊙, comparable to the dynamical mass estimate and four times larger than the H_2 mass found from the CO(4 →3) line. While our observations confirm that this SMG is massive and highly gas-rich, they also suggest that J_(upper) > 3 transitions of CO may not accurately trace cold, diffuse molecular gas in SMGs

Comparison of Driver Brake Reaction Times to Multimodal Rear-end Collision Warnings

This study examined the effectiveness of rear-end collision warnings presented in different sensory modalities as a function of warning timing in a driving simulator. Drivers experienced four warning conditions: no warning, visual, auditory, and tactile. The warnings activated when the time-to-collision (TTC) reached a critical value of 3.0 or 5.0 s TTC. Driver reaction time (RT) was captured from the time the driver crossed the warning activation threshold to brake initiation. Mean driver RT data showed that the tactile warning significantly outperformed the visual warning, providing support for tactile displays as effective rear-end collision warnings