3D head motion, point-of-regard and encoded gaze fixations in real scenes: next-generation portable video-based monocular eye tracking

Portable eye trackers allow us to see where a subject is looking when performing a natural task with free head and body movements. These eye trackers include headgear containing a camera directed at one of the subject\u27s eyes (the eye camera) and another camera (the scene camera) positioned above the same eye directed along the subject\u27s line-of-sight. The output video includes the scene video with a crosshair depicting where the subject is looking -- the point-of-regard (POR) -- that is updated for each frame. This video may be the desired final result or it may be further analyzed to obtain more specific information about the subject\u27s visual strategies. A list of the calculated POR positions in the scene video can also be analyzed. The goals of this project are to expand the information that we can obtain from a portable video-based monocular eye tracker and to minimize the amount of user interaction required to obtain and analyze this information. This work includes offline processing of both the eye and scene videos to obtain robust 2D PORs in scene video frames, identify gaze fixations from these PORs, obtain 3D head motion and ray trace fixations through volumes-of-interest (VOIs) to determine what is being fixated, when and where (3D POR). To avoid the redundancy of ray tracing a 2D POR in every video frame and to group these POR data meaningfully, a fixation-identification algorithm is employed to simplify the long list of 2D POR data into gaze fixations. In order to ray trace these fixations, the 3D motion -- position and orientation over time -- of the scene camera is computed. This camera motion is determined via an iterative structure and motion recovery algorithm that requires a calibrated camera and knowledge of the 3D location of at least four points in the scene (that can be selected from premeasured VOI vertices). The subjects 3D head motion is obtained directly from this camera motion. For the final stage of the algorithm, the 3D locations and dimensions of VOIs in the scene are required. This VOI information in world coordinates is converted to camera coordinates for ray tracing. A representative 2D POR position for each fixation is converted from image coordinates to the same camera coordinate system. Then, a ray is traced from the camera center through this position to determine which (if any) VOI is being fixated and where it is being fixated -- the 3D POR in the world. Results are presented for various real scenes. Novel visualizations of portable eye tracker data created using the results of our algorithm are also presented

Clinical Legal Education Through the Looking-Glass

This paper describes the implementation of a clinical legal education program at the University of Western Ontario. By coincidence, the paper was completed just as a major change in direction was unfolding in the program. The origin and purposes of clinical education I will leave to another occasion. Suffice it to say that my answer to the question, does a law school need clinical education? , is a resounding yes

Community-level response of coastal microbial biofilms to ocean acidification in a natural carbon dioxide vent ecosystem.

The version on PEARL: Corrected proofs are Articles in Press that contain the authors' corrections. Final citation details, e.g., volume/issue number, publication year and page numbers, still need to be added and the text might change before final publication. Although corrected proofs do not have all bibliographic details available yet, they can already be cited using the year of online publication and the DOI , as follows: author(s), article title, journal (year), DOIThe impacts of ocean acidification on coastal biofilms are poorly understood. Carbon dioxide vent areas provide an opportunity to make predictions about the impacts of ocean acidification. We compared biofilms that colonised glass slides in areas exposed to ambient and elevated levels of pCO(2) along a coastal pH gradient, with biofilms grown at ambient and reduced light levels. Biofilm production was highest under ambient light levels, but under both light regimes biofilm production was enhanced in seawater with high pCO(2). Uronic acids are a component of biofilms and increased significantly with high pCO(2). Bacteria and Eukarya denaturing gradient gel electrophoresis profile analysis showed clear differences in the structures of ambient and reduced light biofilm communities, and biofilms grown at high pCO(2) compared with ambient conditions. This study characterises biofilm response to natural seabed CO(2) seeps and provides a baseline understanding of how coastal ecosystems may respond to increased pCO(2) levels

The PPMXL catalog of positions and proper motions on the ICRS. Combining USNO-B1.0 and 2MASS

USNO-B1.0 and 2MASS are the most widely used full-sky surveys. However, 2MASS has no proper motions at all, and USNO-B1.0 published only relative, not absolute (i.e. on ICRS) proper motions. We performed a new determination of mean positions and proper motions on the ICRS system by combining USNO-B1.0 and 2MASS astrometry. This catalog is called PPMXL {VO-access to the catalog is possible via http://vo.uni-hd.de/ppmxl}, and it aims to be complete from the brightest stars down to about $V \approx 20$ full-sky. PPMXL contains about 900 million objects, some 410 million with 2MASS photometry, and is the largest collection of ICRS proper motions at present. As representative for the ICRS we chose PPMX. The recently released UCAC3 could not be used because we found plate-dependent distortions in its proper motion system north of -20$^\circ$ declination. UCAC3 served as an intermediate system for $\delta \leq -20^\circ$. The resulting typical individual mean errors of the proper motions range from 4 mas/y to more than 10 mas/y depending on observational history. The mean errors of positions at epoch 2000.0 are 80 to 120 mas, if 2MASS astrometry could be used, 150 to 300 mas else. We also give correction tables to convert USNO-B1.0 observations of e.g. minor planets to the ICRS system.Comment: 9 pages, 9 figure

Inverse monoids and immersions of 2-complexes

It is well known that under mild conditions on a connected topological space $\mathcal X$, connected covers of $\mathcal X$ may be classified via conjugacy classes of subgroups of the fundamental group of $\mathcal X$. In this paper, we extend these results to the study of immersions into 2-dimensional CW-complexes. An immersion $f : {\mathcal D} \rightarrow \mathcal C$ between CW-complexes is a cellular map such that each point $y \in {\mathcal D}$ has a neighborhood $U$ that is mapped homeomorphically onto $f(U)$ by $f$. In order to classify immersions into a 2-dimensional CW-complex $\mathcal C$, we need to replace the fundamental group of $\mathcal C$ by an appropriate inverse monoid. We show how conjugacy classes of the closed inverse submonoids of this inverse monoid may be used to classify connected immersions into the complex

The High-Order-Multiplicity of Unusually Wide M-dwarf Binaries: Eleven New Triple and Quadruple Systems

M-dwarfs in extremely wide binary systems are very rare, and may thus have different formation processes from those found as single stars or close binaries in the field. In this paper we search for close companions to a new sample of 36 extremely wide M-dwarf binaries, covering a spectral type range of M1 to M5 and a separation range of 600 - 6500 AU. We discover 10 new triple systems and one new quadruple system. We carefully account for selection effects including proper motion, magnitude limits, the detection of close binaries in the SDSS, and other sample biases. The bias-corrected total high-order-multiple fraction is 45% (+18%/-16%) and the bias-corrected incidence of quadruple systems is < 5%, both statistically compatible with that found for the more common close M-dwarf multiple systems. Almost all the detected companions have similar masses to their primaries, although two very low mass companions, including a candidate brown dwarf, are found at relatively large separations. We find that the close-binary separation distribution is strongly peaked towards < 30AU separations. There is marginally significant evidence for a change in high-order M-dwarf multiplicity with binding energy and total mass. We also find 2-sigma evidence of an unexpected increased high-order-multiple fraction for the widest targets in our survey, with a high-order-multiple fraction of 21% (+17%/-7%) for systems with separations up to 2000AU, compared to 77% (+9%/-22%) for systems with separations > 4000AU. These results suggest that the very widest M-dwarf binary systems need higher masses to form or to survive.Comment: 11 pages, 14 figures, accepted for publication in Ap

Appreciative inquiry for stress management

Purpose: The purpose of this paper is to demonstrate the innovative application of an Appreciative Inquiry (AI) approach for the design and implementation of organizational stress management interventions, alongside a case study of the successful design and implementation of the approach. By utilizing the AI methodology to develop a “local stress theory” for the participating organization, the authors propose a model which can be utilized in other similar organizations. Design/methodology/approach: Stage 1: 35 participants completed up to ten daily logs by answering four positively framed questions regarding their working day. Stage 2: semi-structured interviews (n=13). The interview schedule was designed to further elaborate log findings, and begin looking into feasible organizational changes for improvement of stress. Stage 3: two focus groups (Stage 3, total 13 employees) verified interventions from logs and interviews and discuss how these can be implemented. Findings: The log phase identified two key themes for improvement: managerial/organizational support and communication. From these, interviews and focus groups led to workable proposals for simple but likely effective changes. The authors reported findings to management, emphasizing organizational change implementation, and these were subsequently implemented. Research limitations/implications: The study demonstrated the effectiveness of AI to identify and implement relatively simple but meaningful changes. The AI cycle was completed but allocating lengthy follow-up time for evaluation of outcomes was not possible, although initial responses were favorable. There are also issues of generalizability of the findings. Originality/value: This is the among first studies to utilize an AI approach for the design of stress management interventions

Impacts of agricultural land use on biological integrity: a causal analysis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116919/1/eap20112183128.pd

Effects of blockade of muscarinic receptors in the ventral tegmental area : attenuation of cocaine reward, but enhancement of locomotor activity and dopamine overflow in the nucleus accumbens

The present study was designed to determine the involvement of cholinergic projections to the ventral tegmental area in the rewarding effects of cocaine. Bilateral intracranial injections of the muscarinic receptor antagonist atropine into the ventral tegmental area attenuated the rewarding effects of intravenous cocaine self-administered on either fixed ratio or progressive ratio schedules of reinforcement. Low doses of atropine sulphate, the lipophilic form of the drug, produced a compensatory increase in cocaine intake while the administration of higher doses of atropine sulphate extinguished responding for intravenous cocaine on a fixed ratio schedule of reinforcement. Bilateral microinjections of atropine methyl nitrate, the lipophobic form of the drug, into the ventral tegmental area also attenuated the rewarding effects of intravenous cocaine self-administered on a progressive ratio schedule of reinforcement. Responding following the injection of low doses of atropine resembled responding when saline was substituted for cocaine, breaking points were established rapidly and there was no post-reinforcement pause. The priming effect of the cocaine administered during "loading" was abolished by the highest dose of atropine; breaking points were reduced. Enhanced locomotion was the predominant effect on activity induced by the administration of atropine into the ventral tegmental area. Atropine sulphate initially induced a period of immobility that did not occur following the administration of atropine methyl nitrate. Microdialysis techniques were used to assess extracellular dopamine levels in the shell of the nucleus accumbens, the terminal region for mesolimbic dopamine neurons originating in the ventral tegmental area. The injection of atropine methyl nitrate into the ventral tegmental area elevated extracellular levels of dopamine and its metabolites in the ipsilateral nucleus accumbens. Thus blockade of muscarinic receptors in the ventral tegmental area reduces cocaine reward, but increases locomotion and mesolimbic dopamine levels. As cocaine reward is believed to be dopamine-dependent, these findings suggest that separate populations of mesolimbic dopamine neurons underlie cholinergic actions on locomotion and reward