Evaluating Outer Segment Length as A Surrogate Measure of Peak Foveal Cone Density

Adaptive optics (AO) imaging tools enable direct visualization of the cone photoreceptor mosaic, which facilitates quantitative measurements such as cone density. However, in many individuals, low image quality or excessive eye movements precludes making such measures. As foveal cone specialization is associated with both increased density and outer segment (OS) elongation, we sought to examine whether OS length could be used as a surrogate measure of foveal cone density. The retinas of 43 subjects (23 normal and 20 albinism; aged 6–67 years) were examined. Peak foveal cone density was measured using confocal adaptive optics scanning light ophthalmoscopy (AOSLO), and OS length was measured using optical coherence tomography (OCT) and longitudinal reflectivity profile-based approach. Peak cone density ranged from 29,200 to 214,000 cones/mm2(111,700 ± 46,300 cones/mm2); OS length ranged from 26.3 to 54.5 μm (40.5 ± 7.7 μm). Density was significantly correlated with OS length in albinism (p \u3c 0.0001), but not normals (p = 0.99). A cubic model of density as a function of OS length was created based on histology and optimized to fit the albinism data. The model includes triangular cone packing, a cylindrical OS with a fixed volume of 136.6 μm3, and a ratio of OS to inner segment width that increased linearly with increasing OS length (R2 = 0.72). Normal subjects showed no apparent relationship between cone density and OS length. In the absence of adequate AOSLO imagery, OS length may be used to estimate cone density in patients with albinism. Whether this relationship exists in other patient populations with foveal hypoplasia (e.g., premature birth, aniridia, isolated foveal hypoplasia) remains to be seen

Effectiveness of extra enforcement in construction and maintenance work zones

As traffic-related work zone crashes continue to increase across the nation, safety of road users and workers has become a top priority for transportation agencies. Since inattention and irresponsible behavior by drivers are surmised to contribute to the frequency of work zone crashes, a program featuring extraordinary presence of and enforcement by law officers has been implemented in many states to address this concern. A literature search of such programs and related research was conducted. While the overall benefits of these activities have been found positive, much of the evidence has been anecdotal. To assess the scope of extra work zone enforcement programs, a survey was developed and distributed to state departments of transportation across the nation. This survey sought information regarding these efforts such as criteria for selection of target work zones, methods of enforcement operations, and beneficial results. A special survey was also designed and distributed to enforcement agencies in Iowa and other selected states. In addition to the surveys, personal contacts and office visits were conducted by the research team staff. The study found that use of extra enforcement in work zones is a common practice in many states and these activities appear to be increasing. Current literature, survey responses, and interviews have all indicated a prevalent opinion for the benefits of increased law enforcement presence and activity in work zones. Very few comments offered conclusions of negative impacts, such as additional congestion, from these efforts. However, the beneficial effects of focused enforcement have not been intensively quantified. In addition, procedures for the use of law officers in work zones are quite inconsistent across the nation, as is the general implementation of specific legislation addressing work zone traffic violations. Similar variation can be found in funding levels and sources for enforcement activities in work zones among the states. Training of law officers prior to work zone duty does not appear to be commonly required, though the value of focused training is being recognized in some states. As crashes and deaths continue to rise annually in our nation\u27s work zones, it is imperative that demonstrated beneficial programs such as the expanded use of law officers in these locations be continued, refined, and expanded. Future study is needed to supplement the knowledge base and provide guidance to agencies when considering the use of law enforcement to calm traffic, ensure compliance with traffic laws, and thus provide for safer work zones

VarSight: prioritizing clinically reported variants with binary classification algorithms.

BackgroundWhen applying genomic medicine to a rare disease patient, the primary goal is to identify one or more genomic variants that may explain the patient's phenotypes. Typically, this is done through annotation, filtering, and then prioritization of variants for manual curation. However, prioritization of variants in rare disease patients remains a challenging task due to the high degree of variability in phenotype presentation and molecular source of disease. Thus, methods that can identify and/or prioritize variants to be clinically reported in the presence of such variability are of critical importance.MethodsWe tested the application of classification algorithms that ingest variant annotations along with phenotype information for predicting whether a variant will ultimately be clinically reported and returned to a patient. To test the classifiers, we performed a retrospective study on variants that were clinically reported to 237 patients in the Undiagnosed Diseases Network.ResultsWe treated the classifiers as variant prioritization systems and compared them to four variant prioritization algorithms and two single-measure controls. We showed that the trained classifiers outperformed all other tested methods with the best classifiers ranking 72% of all reported variants and 94% of reported pathogenic variants in the top 20.ConclusionsWe demonstrated how freely available binary classification algorithms can be used to prioritize variants even in the presence of real-world variability. Furthermore, these classifiers outperformed all other tested methods, suggesting that they may be well suited for working with real rare disease patient datasets

The Reliability of Parafoveal Cone Density Measurements

Background Adaptive optics scanning light ophthalmoscopy (AOSLO) enables direct visualisation of the cone mosaic, with metrics such as cone density and cell spacing used to assess the integrity or health of the mosaic. Here we examined the interobserver and inter-instrument reliability of cone density measurements. Methods For the interobserver reliability study, 30 subjects with no vision-limiting pathology were imaged. Three image sequences were acquired at a single parafoveal location and aligned to ensure that the three images were from the same retinal location. Ten observers used a semiautomated algorithm to identify the cones in each image, and this was repeated three times for each image. To assess inter-instrument reliability, 20 subjects were imaged at eight parafoveal locations on one AOSLO, followed by the same set of locations on the second AOSLO. A single observer manually aligned the pairs of images and used the semiautomated algorithm to identify the cones in each image. Results Based on a factorial study design model and a variance components model, the interobserver study\u27s largest contribution to variability was the subject (95.72%) while the observer\u27s contribution was only 1.03%. For the inter-instrument study, an average cone density intraclass correlation coefficient (ICC) of between 0.931 and 0.975 was calculated. Conclusions With the AOSLOs used here, reliable cone density measurements can be obtained between observers and between instruments. Additional work is needed to determine how these results vary with differences in image quality

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Effectiveness of extra enforcement in construction and maintenance work zones

As traffic-related work zone crashes continue to increase across the nation, safety of road users and workers has become a top priority for transportation agencies. Since inattention and irresponsible behavior by drivers are surmised to contribute to the frequency of work zone crashes, a program featuring extraordinary presence of and enforcement by law officers has been implemented in many states to address this concern. A literature search of such programs and related research was conducted. While the overall benefits of these activities have been found positive, much of the evidence has been anecdotal. To assess the scope of extra work zone enforcement programs, a survey was developed and distributed to state departments of transportation across the nation. This survey sought information regarding these efforts such as criteria for selection of target work zones, methods of enforcement operations, and beneficial results. A special survey was also designed and distributed to enforcement agencies in Iowa and other selected states. In addition to the surveys, personal contacts and office visits were conducted by the research team staff. The study found that use of extra enforcement in work zones is a common practice in many states and these activities appear to be increasing. Current literature, survey responses, and interviews have all indicated a prevalent opinion for the benefits of increased law enforcement presence and activity in work zones. Very few comments offered conclusions of negative impacts, such as additional congestion, from these efforts. However, the beneficial effects of focused enforcement have not been intensively quantified. In addition, procedures for the use of law officers in work zones are quite inconsistent across the nation, as is the general implementation of specific legislation addressing work zone traffic violations. Similar variation can be found in funding levels and sources for enforcement activities in work zones among the states. Training of law officers prior to work zone duty does not appear to be commonly required, though the value of focused training is being recognized in some states. As crashes and deaths continue to rise annually in our nation's work zones, it is imperative that demonstrated beneficial programs such as the expanded use of law officers in these locations be continued, refined, and expanded. Future study is needed to supplement the knowledge base and provide guidance to agencies when considering the use of law enforcement to calm traffic, ensure compliance with traffic laws, and thus provide for safer work zones.For more information, please visit http://www.intrans.iastate.edu/</p

Tripple-Bottom-Line Analysis : Sit-Stand Desks vs Regular Desks

This project was originally assigned as part of UBC’s SEEDS sustainability program, an initiative whose vision is to help form collaborations between students and faculty on innovative projects that align with UBC’s values. The implementation of sit-stand desks throughout the University of British Columbia campus has been an area of interest for its faculties and governing bodies. Although a small number of desks have been installed in various faculties (Abigail Overduin, personal communication, March 29, 2016), no steadfast plan has been developed for a full-scale campus wide implementation. Others research tends to focus primarily on the health benefits of the sit-stand desk and falls short of a complete analysis, specifically using the triple-bottom-line (TBL) approach. This report provides a solution that encompasses a wide variety of factors from economic, social and environmental or TBL. Using this approach we were able to develop a balanced sit-stand desk execution plan without bias towards one of the latter three factors. Disclaimer: “UBC SEEDS provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student project/report and is not an official document of UBC. Furthermore readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or the SEEDS Coordinator about the current status of the subject matter of a project/report.”Applied Science, Faculty ofUnreviewedUndergraduat