Light Res Technol

Proper lighting plays a critical role in enabling miners to detect hazards when operating a roof bolter, one of the most dangerous mining machines to operate; however, there has not been any lighting research to address the walk-thru type of roof bolter commonly used today. To address this, the Saturn light was designed to directly address walk-thru roof bolter safety by improving trip hazard illumination. The visual performances of 30 participants that comprised three age groups were quantified by measuring each participant's visual performance in detecting trip objects positioned on the two floor locations within the machine's interior working space. The lighting conditions were the existing compact fluorescent lights (CFLs) and the Saturn LED area light developed by NIOSH researchers. Three intensities of the Saturn lights were used, 100%, 75%, and 50%, all of which resulted in better visual performance, and up to a 48% reduction in average trip detection time compared to the CFL. For the Saturn trip object miss rates were <0.5% for all age groups in contrast to the CFL, which ranged between 32.5% for the youngest group and 50.4% for the oldest group.CC999999/Intramural CDC HHS/United States2020-08-01T00:00:00Z30174557PMC61126068081vault:3256

Trans Soc Min Metall Explor Inc

The Illuminating Engineering Society of North America reports that an underground mine is the most difficult environment to illuminate (Rea, 2000). Researchers at the U.S. National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) are conducting ongoing studies designed to explore different lighting technologies for improving mine safety. Underground miners use different visual cues to escape from a smoke-filled environment. Primary and secondary escapeways are marked with reflective ceiling tags of various colors. Miners also look for mine rail tracks. The main objective of this paper is to compare different lighting types and ceiling tag colors to differentiate what works best in a smoke-filled environment. Various cap lamps (LED and incandescent) and lasers (red, blue, green) were compared to see which options resulted in the longest detection distances for red, green and blue reflective markers and a section of mine rail track. All targets advanced toward the human subject inside of a smoke-filled room to simulate the subject walking in a mine environment. Detection distances were recorded and analyzed to find the best cap lamp, laser color and target color in a smoke environment. Results show that cap lamp, laser color and target color do make a difference in detection distances and are perceived differently based on subject age. Cap lamps were superior to lasers in all circumstances of ceiling tag detection, with the exception of the green laser. The incandescent cap lamp worked best in the simulated smoke compared to the LED cap lamps. The green laser was the best color for detecting the tags and track compared to the red and blue lasers. The green tags were the easiest color to detect on the ceiling. On average, the track was easier for the subjects to detect than the ceiling tags.YLH8/Intramural CDC HHS/United States2015-07-31T00:00:00Z26236146PMC452199

Int J Ind Ergon

Researchers at the National Institute for Occupational Safety and Health (NIOSH) are conducting mine illumination research with the objective of improving miner safety. Slips, trips, and falls (STFs) are the second leading accident class (18.1%, n = 2,374) of nonfatal lost-time injuries at underground mines (MSHA, 2005-2009). Factors contributing to STFs include recognition of hazards as well as postural balance and age. Improved lighting may enable better hazard recognition and reduce the impact of postural balance and age. Previous research has shown that cap lamp technology that used light-emitting diodes (LEDs) has improved hazard detection. This study was an initial investigation to determine if cap lamp lighting significantly influences measures of static postural stability (displacement and velocity of center of pressure). Results of this investigation showed no significant differences in the balance measures of interest between cap lamps tested. However, balance was shown to significantly decline (p < 0.05) when tested in an underground coal mine compared to the laboratory testing condition. Relevance to industry: Underground coal mine workers wear cap lamps on their hard hats as their primary light source to illuminate nearby areas where their vision is directed. Proper illumination may improve miner safety by improving their STF hazard recognition and balance.YLH8/Intramural CDC HHS/United States2015-10-13T00:00:00Z26472917PMC460405

Repeatability and reproducibility of visual field tests in people with established visual field loss

The thesis investigated the repeatability of the Esterman Visual Field Test (EVFT) on the Humphrey Field Analyser (HFA), and the reproducibility of the EVFT on the HFA and Henson Pro 5000 Perimeter. The reproducibility of the Ring of Sight (ROS) 24-2 full threshold (FT) examination was also evaluated. These were investigated with participants with established visual field loss (VFL) using case control studies. The reduced sensitivity that influences test-retest variability in those with VFL and differences within the perimeter methodologies, including the influence of background luminance were considered. Agreement in sensitivity threshold values or the Esterman Efficiency Scores (EES) between perimeters were analysed and pointwise analysis was undertaken. Any change in fitness-to-drive status or ability to determine/rule out disease was investigated. Principal Findings: The EVFT possesses poor repeatability and reproducibility for individuals with VFL with significant change in EES on test-retest at different sessions and significant lack of agreement when comparing EES on the HFA and the Henson Pro 5000 Perimeter. The EVFT possesses good repeatability and reproducibility in fitness-to-drive status. The significant variation in EES and location of defect in those with VFL does not impact upon on an individual’s fitness-to-drive status. It is recommended that a repeat examination is performed on the HFA for those with VFL who fails the EVFT on initial examination to account for variability of test-retest and the significantly lower EES recorded by the Henson Pro 5000 Perimeter. There is a large proportion of those with VFL (33.33%) who are unable to see a target, which is required to be seen, in order to conduct a visual field test on the ROS. There is significant lack of agreement in defect depth, defect location, mean deviation and sensitivity threshold values found on the ROS 24-2 FT examination compared to the SITA Standard 24-2 examination performed on the HFA. The ROS possesses a sensitivity value of 33.33%

NOIRS 2008

"The National Institute for Occupational Safety and Health (NIOSH) hosted the fourth National Occupational Injury Research Symposium (NOIRS) on October 21-23, 2008 at the Sheraton Station Square in Pittsburgh, Pennsylvania. NOIRS is the only forum for the presentation of occupational injury research findings, data, and methods. This symposium served numerous objectives aimed at preventing traumatic occupational injury through research and prevention. They included: 1. Presenting current research findings. 2. Fostering collaboration among researchers from a broad range of disciplines and perspectives, and exploring underutilized disciplines and topic areas. 3. Identifying best practices in the area of intervention evaluation. 4. Exploring the cost-effectiveness of injury prevention strategies and interventions. 5. Showcasing innovative and high technology approaches to research and prevention. 6. Continuing to promote the implementation of NORA. Questions that were addressed included: 1. What are the latest traumatic occupational injury research findings? 2. What are emerging problem areas in workplace trauma? 3. How is prevention through design being applied to occupational injury research and prevention? 4. What activities are being done to implement research to practice in the area of traumatic occupational injury? 5. What are the best practice intervention and prevention strategies and which strategies do not work? In what specific workplaces and under what circumstances? 6. What are the economic costs of traumatic occupational injuries and how cost-effective are the prevention strategies? 7. What are current and emerging research areas and disciplines? 8. What are the trends in traumatic occupational injury and fatality incidence? In research tools, techniques, and methods? In prevention? 9. What specific workplace risks are faced by adolescents, older adults, minority workers, non-English-speaking workers, low-literacy workers, and other special populations? 10. How can researchers and practitioners in different sectors and disciplines better collaborate and coordinate their activities to reduce traumatic occupational injuries? 11. What methods are available to assess, quantify, and compare traumatic occupational injury risks? Occupational injury researchers from all disciplines were invited to attend and share their research. We encouraged participation by all interested individuals, including: Safety researchers; Safety practitioners; Health care professionals; Administrators; Epidemiologists; Engineers; Manufacturers; Communication Researchers; Health and science communicators; Regulators; Employers; Policy makers; Insurers; Students; Advocates; Workers; Educators and trainers; and, Others interested in attending. The symposium consisted of contributed oral presentations in concurrent sessions and a poster session." - NIOSHTIC-2Available via the World Wide Web as an Acrobat .pdf file (1.30 MB, 92 p.)

Retinal function of the voltage-gated calcium channel subunit α2δ-3 / Light-dependent effects in α2δ-3 mutant and in wild type retina

The retina employs a large number of cell types that fulfill a broad spectrum of computations. It comes as no surprise that this complex network would make use of an equal diversity of molecular tools, such as voltage-gated calcium channels (VGCC). In fact, all pore-forming α1 subunits of VGCC and modulatory β and auxiliary α2δ subunits were found in the retina. Yet, little detail is known about the functional implementation of individual VGCC subunits in the retinal circuitry. My work described in part 1 focused on the retinal expression and function of one VGCC subunit, called α2δ-3, employing an α2δ-3 knockout mouse. I found transcription of all α2δ subunit genes throughout postnatal retinal development and strong expression of α2δ-3 in horizontal cells. Yet, in my patch-clamp recordings from isolated horizontal cells I did not find an impact on their somatic calcium currents, leaving a possible involvement of α2δ-3 in the horizontal cell axon-to-rod connection. Outer retina function, determined by electroretinogram, and optokinetic reflex behavior was normal in α2δ-3 knockout animals. However, I discovered changes to the retinal output in micro-electrode array recordings of ganglion cell responses. I applied a paradigm of light stimulation at different ambient luminance levels that revealed effects of the α2δ-3 knockout only in scotopic and mesopic light levels. In summary, α2δ-3 is a candidate for horizontal cell axon-specific calcium signal modulation and exerts its function in non-photopic regimes. The retina constantly adapts to features of the current visual environment, most prominently, the ambient light intensity or luminance. These adaptations are based on mechanisms throughout the retinal network. Adaption is commonly considered to keep signal processing within the dynamic range of the system as well as keep the retinal output stable across changing conditions, such as the light intensity. The results of part 1 show that different building blocks of retinal circuits - here the α2δ-3 subunit - can contribute to retinal function at distinct light level regimes. In part 2, we looked more generally at the output of the retina (responses of ganglion cells) across different levels of ambient luminance. We found that ganglion cell responses were not stable across luminance levels, neither in single ganglion cell types nor in the ganglion cell population, but that they changed their responses qualitatively. These response changes were also reflected downstream in the activity of the lateral geniculate nucleus. Furthermore, we observed that rod photoreceptors could drive visual responses of ganglion cells in photopic luminance levels, where they were commonly thought to be saturated. While experiencing initial incremental saturation upon stepping to photopic luminance, rods recovered responsiveness at all light levels tested, but the rate of recovery was faster with brighter ambient light intensity. Computational modeling suggested adaptive translocation of elements of the signal transduction cascade as potential explanations for rod signaling at high light intensities. The photopic rod activity dynamics have important implications for the interpretation of experimental data and for the question of rod photoreceptor contributions to daylight vision. In summary, while some circuitry elements associated with luminance regimes are known (e.g. rod and cone pathways), details on the underlying molecular mechanisms are scarce. My data suggests α2δ-3 as a promising candidate for a molecular determinant of light adaptation that could exert its function within horizontal cells in an axonal compartment-specific way. It will be interesting to pinpoint the exact role of α2δ- 3 in retinal light adaptation and to determine what (sub-)cellular function this protein serves in horizontal cells

Hyperspectral colour imaging and spectrophotometric instrumentation

The trichromatic nature of commercial photography is strictly connected with the nature of human colour vision, although the characteristics of usual colour imaging devices are quite different from the human visual system. The increase in the number of colour channels for spectral (either multispectral or hyperspectral) imaging is an active field of research with many potential applications in different fields. Each element of the captured scene is specified in the spectral image by the spectral reflectance factor. This measurement is independent of the particular illumination of the scene and allows the colorimetric computation in a device-independent colour space for any chosen illuminant and any observer. This thesis describes the project and construction of a compact spectrophotometric camera, which can be used in both portable and in-situ applications. The compactness is made possible by a suitable image spectral scanning based on an Induced Transmission Filter (ITF). This filter is made by a set of thin-film coatings of dielectric materials with high and low refraction index, whose shape like a wedge induces a wavelength selective transmittance, continuously variable along one direction and uniform in the perpendicular direction. Such a filter, classified as Linearly Variable Filter (LVF), operates continuously from 430nm to 940nm and allows hyperspectral imaging. In traditional scanners the whole apparatus is moved along a path as long as the scene, whereas in this instrument the camera body is still and the LVF is the only moving part. The sequence of operations for wavelength and radiometric calibrations are discussed. The expected acquisition times and number of images as a function of the spectral sampling step are considered. The resulting properties make the instrument easy to use and with short acquisition times. Moreover, overviews of the historic evolution of colour vision fundamentals, colour spaces and spectral imaging technology are given for introducing the reader to the essential concepts useful for the understanding of the text

Inverse tone mapping

The introduction of High Dynamic Range Imaging in computer graphics has produced a novelty in Imaging that can be compared to the introduction of colour photography or even more. Light can now be captured, stored, processed, and finally visualised without losing information. Moreover, new applications that can exploit physical values of the light have been introduced such as re-lighting of synthetic/real objects, or enhanced visualisation of scenes. However, these new processing and visualisation techniques cannot be applied to movies and pictures that have been produced by photography and cinematography in more than one hundred years. This thesis introduces a general framework for expanding legacy content into High Dynamic Range content. The expansion is achieved avoiding artefacts, producing images suitable for visualisation and re-lighting of synthetic/real objects. Moreover, it is presented a methodology based on psychophysical experiments and computational metrics to measure performances of expansion algorithms. Finally, a compression scheme, inspired by the framework, for High Dynamic Range Textures, is proposed and evaluated

Advances in Ophthalmology

This book focuses on the different aspects of ophthalmology - the medical science of diagnosis and treatment of eye disorders. Ophthalmology is divided into various clinical subspecialties, such as cornea, cataract, glaucoma, uveitis, retina, neuro-ophthalmology, pediatric ophthalmology, oncology, pathology, and oculoplastics. This book incorporates new developments as well as future perspectives in ophthalmology and is a balanced product between covering a wide range of diseases and expedited publication. It is intended to be the appetizer for other books to follow. Ophthalmologists, researchers, specialists, trainees, and general practitioners with an interest in ophthalmology will find this book interesting and useful

Inverse tone mapping

The introduction of High Dynamic Range Imaging in computer graphics has produced a novelty in Imaging that can be compared to the introduction of colour photography or even more. Light can now be captured, stored, processed, and finally visualised without losing information. Moreover, new applications that can exploit physical values of the light have been introduced such as re-lighting of synthetic/real objects, or enhanced visualisation of scenes. However, these new processing and visualisation techniques cannot be applied to movies and pictures that have been produced by photography and cinematography in more than one hundred years. This thesis introduces a general framework for expanding legacy content into High Dynamic Range content. The expansion is achieved avoiding artefacts, producing images suitable for visualisation and re-lighting of synthetic/real objects. Moreover, it is presented a methodology based on psychophysical experiments and computational metrics to measure performances of expansion algorithms. Finally, a compression scheme, inspired by the framework, for High Dynamic Range Textures, is proposed and evaluated.EThOS - Electronic Theses Online ServiceEngineering and Physical Sciences Research Council (EPSRC) (EP/D032148)GBUnited Kingdo