WorldWideScience

Sample records for permanent vision loss

  1. Living with vision loss

    Science.gov (United States)

    Diabetes - vision loss; Retinopathy - vision loss; Low vision; Blindness - vision loss ... of visual aids. Some options include: Magnifiers High power reading glasses Devices that make it easier to ...

  2. Postraumatic delayed loss of vision

    International Nuclear Information System (INIS)

    Partington, C.R.; Graves, V.B.; Ruetenacht, D.A.; Weinstein, J.M.; Strother, C.M.

    1989-01-01

    The imaging studies and clinical findings in 10 patients who suffered delayed vision loss beginning 1 day to 13 years after head trauma have been reviewed. Two different primary lesions could be identified: pseudoaneurysm of the internal carotid artery and carotid cavernous fistula. The pathologic changes associated with pseudoaneurysm included compression of the optic nerves and/or chiasm by arterial aneurysm and intracranial hematoma. Carotid cavernous fistula caused delayed vision loss by compression of the optic nerves and chiasm by saccular dilatation of the cavernous sinus and by abnormal orbital venous drainage with retinal venous stasis, retinal edema, and glaucoma

  3. Acute Vision Loss Following Endoscopic Sinus Surgery

    Directory of Open Access Journals (Sweden)

    Serena Byrd

    2017-01-01

    Full Text Available A 41-year-old female with a history of uterine cancer and Celiac and Raynaud’s Disease presented to our institution with frequent migraines and nasal congestion. She underwent functional endoscopic sinus surgery (FESS and experienced acute unilateral vision loss postoperatively. Rapid recognition of the etiology and effective treatment are paramount given the permanent and irreversible vision loss that can result. Arterial vasospasm following FESS is rare. Patients with autoimmune diseases have perhaps an increased risk for vasospasm secondary to an increased vasoreactive profile. We present the first documented case of nitroglycerin sublingual therapy to successfully treat ophthalmic artery vasospasm following FESS. Nitroglycerin sublingual therapy is a promising treatment for ophthalmic vasospasm secondary to its ability to cross the blood-ocular barrier, its rapid onset of action, and its ability to promote relaxation of vascular smooth muscle.

  4. Functional vision loss: a diagnosis of exclusion.

    Science.gov (United States)

    Villegas, Rex B; Ilsen, Pauline F

    2007-10-01

    Most cases of visual acuity or visual field loss can be attributed to ocular pathology or ocular manifestations of systemic pathology. They can also occasionally be attributed to nonpathologic processes or malingering. Functional vision loss is any decrease in vision the origin of which cannot be attributed to a pathologic or structural abnormality. Two cases of functional vision loss are described. In the first, a 58-year-old man presented for a baseline eye examination for enrollment in a vision rehabilitation program. He reported bilateral blindness since a motor vehicle accident with head trauma 4 years prior. Entering visual acuity was "no light perception" in each eye. Ocular health examination was normal and the patient made frequent eye contact with the examiners. He was referred for neuroimaging and electrophysiologic testing. The second case was a 49-year-old man who presented with a long history of intermittent monocular diplopia. His medical history was significant for psycho-medical evaluations and a diagnosis of factitious disorder. Entering uncorrected visual acuities were 20/20 in each eye, but visual field testing found constriction. No abnormalities were found that could account for the monocular diplopia or visual field deficit. A diagnosis of functional vision loss secondary to factitious disorder was made. Functional vision loss is a diagnosis of exclusion. In the event of reduced vision in the context of a normal ocular health examination, all other pathology must be ruled out before making the diagnosis of functional vision loss. Evaluation must include auxiliary ophthalmologic testing, neuroimaging of the visual pathway, review of the medical history and lifestyle, and psychiatric evaluation. Comanagement with a psychiatrist is essential for patients with functional vision loss.

  5. Perioperative Vision Loss in Cervical Spinal Surgery.

    Science.gov (United States)

    Gabel, Brandon C; Lam, Arthur; Chapman, Jens R; Oskouian, Rod J; Nassr, Ahmad; Currier, Bradford L; Sebastian, Arjun S; Arnold, Paul M; Hamilton, Steven R; Fehlings, Michael G; Mroz, Thomas E; Riew, K Daniel

    2017-04-01

    Retrospective multicenter case series. To assess the rate of perioperative vision loss following cervical spinal surgery. Medical records for 17 625 patients from 21 high-volume surgical centers from the AOSpine North America Clinical Research Network who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, inclusive, were reviewed to identify occurrences of vision loss following surgery. Of the 17 625 patients in the registry, there were 13 946 patients assessed for the complication of blindness. There were 9591 cases that involved only anterior surgical approaches; the remaining 4355 cases were posterior and/or circumferential fusions. There were no cases of blindness or vision loss in the postoperative period reported during the sampling period. Perioperative vision loss following cervical spinal surgery is exceedingly rare.

  6. Preventing Vision Loss in Diabetes - Summary

    Centers for Disease Control (CDC) Podcasts

    2008-04-24

    This podcast is for a professional audience and briefly discusses how to prevent vision loss in people with diabetes.  Created: 4/24/2008 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP), Division of Diabetes Translation (DDT), National Diabetes Education Program (NDEP).   Date Released: 6/4/2008.

  7. Medical student and patient perceptions of quality of life associated with vision loss.

    Science.gov (United States)

    Chaudry, Imtiaz; Brown, Gary C; Brown, Melissa M

    2015-06-01

    Because most medical schools in the United States and Canada require no formal ophthalmology training, the authors queried medical student and ophthalmic patients to compare their perceptions of the quality of life (QOL) associated with vision loss. Cross-sectional comparative study of consecutive medical students and patients with vision loss using a validated, reliable, time trade-off utility instrument. Consecutive Jefferson Medical College medical students (cohort 1: 145 second-year student; cohort 2: 112 third-year/fourth-year students) and 283 patients with vision loss (patient cohort). Time trade-off vision utilities with anchors of 0.0 (death) to 1.0 (normal vision permanently) were used to quantify the QOL associated with vision loss. Students were asked to assume they had: (i) mild vision loss (20/40 to 20/50 vision in the better-seeing eye), (ii) legal blindness (20/200 in the better-seeing eye), and (iii) absolute blindness (no light perception bilaterally). Mean utilities for cohort 1/cohort 2 were 0.96/0.95 (p = 0.20) for mild vision loss, 0.88/0.84 for legal blindness (p = 0.009), and 0.80/0.67 (p student/patient mean utilities were 0.96/0.79 (p students underestimated the QOL associated with vision loss referent to patients with vision loss by 153%-425%. Medical students dramatically underestimated the impact of vision loss on patient QOL. Clinical training slightly improved medical student perceptions. Trivialization of vision loss could result in systemic health harm, less ophthalmic research dollars, loss of the finest medical students entering ophthalmology, and overall adverse financial effects for the field. Copyright © 2015. Published by Elsevier Inc.

  8. Color Vision Losses in Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Elaine C. Zachi

    2017-06-01

    Full Text Available Autism spectrum disorders (ASDs are neurodevelopmental conditions characterized by impairments in social/communication abilities and restricted behaviors. The present study aims to examine color vision discrimination in ASD children and adolescents without intellectual disability. The participants were also subdivided in order to compare color vision thresholds of autistic participants and those who achieved diagnostic criteria for Asperger Syndrome (AS. Nine subjects with autism, 11 participants with AS and 36 typically developing children and adolescents participated in the study. Color vision was assessed by the Cambridge Color Test (CCT. The Trivector protocol was administered to determine color discrimination thresholds along the protan, deutan, and tritan color confusion lines. Data from ASD participants were compared to tolerance limits for 90% of the population with 90% probability obtained from controls thresholds. Of the 20 ASD individuals examined, 6 (30% showed color vision losses. Elevated color discrimination thresholds were found in 3/9 participants with autism and in 3/11 AS participants. Diffuse and tritan deficits were found. Mechanisms for chromatic losses may be either at the retinal level and/or reflect reduced cortical integration.

  9. Permanent Magnet Eddy Current Loss Analysis of a Novel Motor Integrated Permanent Magnet Gear

    DEFF Research Database (Denmark)

    Zhang, Yuqiu; Lu, Kaiyuan; Ye, Yunyue

    2012-01-01

    In this paper, a new motor integrated permanent magnet gear (MIPMG) is discussed. The focus is on eddy current loss analysis associated to permanent magnets (PMs). A convenient model of MIPMG is provided based on 2-D field-motion coupled time-stepping finite element method for transient eddy...... current analysis. The model takes the eddy current effect of PMs into account in determination of the magnetic field in the air-gap and in the magnet regions. The eddy current losses generated in the magnets are properly interpreted. Design improvements for reducing the eddy current losses are suggested...

  10. An improved iron loss estimation for permanent magnet brushless machines

    CERN Document Server

    Fang, D

    1999-01-01

    This paper presents an improved approach for predicting iron losses in permanent magnet brushless machines. The new approach is based on the fundamental concept that eddy current losses are proportional to the square of the time rate of change of flux density. Expressions are derived for predicting hysteresis and eddy current losses in the stator teeth and yoke. The so-called anomalous or excess losses, caused by the induced eddy current concentration around moving magnetic domain walls and neglected in the conventional core loss calculation, are also included in the proposed approach. In addition, the model is also capable of accounting for the stator skewing, if present. The core losses obtained from the proposed approach are compared with those measured on an existing PM motor at several operating speeds, showing very good agreement. (14 refs).

  11. Visual Memory for Objects Following Foveal Vision Loss

    Science.gov (United States)

    Geringswald, Franziska; Herbik, Anne; Hofmüller, Wolfram; Hoffmann, Michael B.; Pollmann, Stefan

    2015-01-01

    Allocation of visual attention is crucial for encoding items into visual long-term memory. In free vision, attention is closely linked to the center of gaze, raising the question whether foveal vision loss entails suboptimal deployment of attention and subsequent impairment of object encoding. To investigate this question, we examined visual…

  12. Participation of the elderly after vision loss

    NARCIS (Netherlands)

    Alma, M.A.; Mei, van der S.F.; Melis-Dankers, B.J.M.; Tilburg, van T.G.; Groothoff, J.W.; Suurmeijer, T.P.B.M.

    2011-01-01

    Purpose. To assess the degree of participation of the visually impaired elderly and to make a comparison with population-based reference data. Method. This cross-sectional study included visually impaired elderly persons (≥55 years; n=173) who were referred to a low-vision rehabilitation centre.

  13. Emergent risk factors associated with eyeball loss and ambulatory vision loss after globe injuries.

    Science.gov (United States)

    Hyun Lee, Seung; Ahn, Jae Kyoun

    2010-07-01

    The objective of this study was to evaluate risk factors associated with eyeball loss and ambulatory vision loss on emergent examination of patients with ocular trauma. We reviewed the medical records of 1,875 patients hospitalized in a single tertiary referral center between January 2003 and December 2007. Emergent examinations included a history of trauma, elapsed time between injury and hospital arrival, visible intraocular tissues, and initial visual acuity (VA) using a penlight. The main outcome measures were ocular survival and ambulatory vision survival (>20/200) at 1 year after trauma using univariate and multivariate regression analysis. The ocular trauma scores were significantly higher in open globe injuries than in closed globe injuries (p eyeball loss. Elapsed time more than 12 hours and visible intraocular tissues were the significant risk factors associated with ambulatory vision loss. The most powerful predictor of eyeball loss and ambulatory vision loss was eyeball rupture. In closed globe injuries, there were no significant risk factors of eyeball loss, whereas initial vision less than LP and the presence of relative afferent pupillary defect were the significant risk factors associated with ambulatory vision loss. An initial VA less than LP using a penlight, a history of golf ball injury, and elapsed time more than 12 hours between ocular trauma and hospital arrival were associated with eyeball loss and ambulatory vision loss. Physicians should bear these factors in mind so that they can more effectively counsel patients with such injuries.

  14. Unilateral Vision Loss after a Dental Visit

    Science.gov (United States)

    Khattab, Mohammed H.; Wiegand, Annette; Storch, Marcus; Hoerauf, Hans; Feltgen, Nicolas

    2018-01-01

    Intraoral local anesthetics are widely used for performing painless dental treatments; however, in some cases, they may cause ocular complications such as meiosis, diplopia, nystagmus, ophthalmoplegia, ptosis, and amaurosis. Mostly, the symptoms disappear after several hours; rarely, they have a prolonged character. We describe the case of a 38-year-old young man who had reduced vision in the left eye 5 days after having received intraoral local anesthesia. A diagnosis of cilioretinal artery occlusion with optic disc swelling was made. Ten weeks later, the patient's visual acuity had increased to 20/20, and the swelling of the optic disc had subsided. Although various possible mechanisms for ocular complications after intraoral local anesthetic administration were suggested in the literature, the exact etiology remains unclear. In this case, inadvertent intravascular injection is believed to be the cause. PMID:29681838

  15. Disseminated neurocysticercosis presenting as isolated acute monocular painless vision loss

    Directory of Open Access Journals (Sweden)

    Gaurav M Kasundra

    2014-01-01

    Full Text Available Neurocysticercosis, the most common parasitic infection of the nervous system, is known to affect the brain, eyes, muscular tissues and subcutaneous tissues. However, it is very rare for patients with ocular cysts to have concomitant cerebral cysts. Also, the dominant clinical manifestation of patients with cerebral cysts is either seizures or headache. We report a patient who presented with acute monocular painless vision loss due to intraocular submacular cysticercosis, who on investigation had multiple cerebral parenchymal cysticercal cysts, but never had any seizures. Although such a vision loss after initiation of antiparasitic treatment has been mentioned previously, acute monocular vision loss as the presenting feature of ocular cysticercosis is rare. We present a brief review of literature along with this case report.

  16. The cost of vision loss in Canada. 2. Results.

    Science.gov (United States)

    Cruess, Alan F; Gordon, Keith D; Bellan, Lorne; Mitchell, Scott; Pezzullo, M Lynne

    2011-08-01

    This study was conducted to provide the financial underpinnings necessary for effective planning for the provision of eye health services in Canada. Canada is facing an aging demographic and all the major eye diseases are diseases associated with aging. It is essential that we have information based on the best available data to support national and provincial vision health plans. The design associated with the prevalence-based approach used in this study was outlined previously in detail in The Cost of Vision Loss in Canada: Methodology. The methods associated with the prevalence-based approach used in this study were previously outlined in detail in The Cost of Vision Loss in Canada: Methodology. The financial cost of VL in Canada in 2007 was estimated to be $15.8 billion per annum: $8.6 billion (54.6%) represents direct health system expenditure; $4.4 billion (28.0%) was productivity lost due to lower employment, higher absenteeism, and premature death of Canadians with VL; $1.8 billion (11.1%) was the dead weight losses (DWL) from transfers including welfare payments and taxation forgone; $0.7 billion (4.4%) was the value of the care for people with VL; $305 million (1.9%) was other indirect costs such as aids and home modifications and the bring forward of funeral costs. Additionally, the value of the lost well-being (disability and premature death) was estimated at a further $11.7 billion. In per capita terms, this amounts to a financial cost of $19370 per person with VL per annum. Including the value of lost well-being, the cost is $33704 per person per annum. There is a growing awareness in Canada and around the world of the impact of VL on health costs and on the economy in general. This awareness is supported by the growing number of independent studies on the cost of vision loss both nationally and globally. Because most of these studies are limited by the minimal amount of available data, the overall cost of vision loss is likely underestimated

  17. Acute vision loss: a fuzzy presentation of sarcoidosis.

    Science.gov (United States)

    Austin, Andrea L; Day, Luke T; Bishop, Frank M

    2013-04-01

    Acute vision loss is a devastating problem for patients and a challenging diagnostic dilemma for Emergency Physicians. This chief complaint is one in which we must be adept at quickly evaluating and initiating either care or referral. This case reviews the approach to acute vision loss and shows the importance of expanding the differential in atypical and complex presentations. A 31-year-old, previously healthy, white woman presented to the Emergency Department (ED) with 1 day of painless right eye vision loss. Ocular ultrasound and slit-lamp examination were unremarkable. Fundoscopic examination revealed retinal hemorrhages and papillitis. Her chest X-ray study was significant for bilateral hilar adenopathy, and subsequent lymph node biopsy confirmed the diagnosis of sarcoidosis. Although sarcoidosis is more common in African Americans, it must be considered in all patients in the appropriate clinical context. Sarcoidosis is an important diagnosis to include on the differential of many chief complaints that present to the ED, including acute vision loss and dyspnea. Published by Elsevier Inc.

  18. Visual memory for objects following foveal vision loss.

    Science.gov (United States)

    Geringswald, Franziska; Herbik, Anne; Hofmüller, Wolfram; Hoffmann, Michael B; Pollmann, Stefan

    2015-09-01

    Allocation of visual attention is crucial for encoding items into visual long-term memory. In free vision, attention is closely linked to the center of gaze, raising the question whether foveal vision loss entails suboptimal deployment of attention and subsequent impairment of object encoding. To investigate this question, we examined visual long-term memory for objects in patients suffering from foveal vision loss due to age-related macular degeneration. We measured patients' change detection sensitivity after a period of free scene exploration monocularly with their worse eye when possible, and under binocular vision, comparing sensitivity and eye movements to matched normal-sighted controls. A highly salient cue was used to capture attention to a nontarget location before a target change occurred in half of the trials, ensuring that change detection relied on memory. Patients' monocular and binocular sensitivity to object change was comparable to controls, even after more than 4 intervening fixations, and not significantly correlated with visual impairment. We conclude that extrafoveal vision suffices for efficient encoding into visual long-term memory. (c) 2015 APA, all rights reserved).

  19. The cost of vision loss in Canada. 1. Methodology.

    Science.gov (United States)

    Gordon, Keith D; Cruess, Alan F; Bellan, Lorne; Mitchell, Scott; Pezzullo, M Lynne

    2011-08-01

    This paper outlines the methodology used to estimate the cost of vision loss in Canada. The results of this study will be presented in a second paper. The cost of vision loss (VL) in Canada was estimated using a prevalence-based approach. This was done by estimating the number of people with VL in a base period (2007) and the costs associated with treating them. The cost estimates included direct health system expenditures on eye conditions that cause VL, as well as other indirect financial costs such as productivity losses. Estimates were also made of the value of the loss of healthy life, measured in Disability Adjusted Life Years or DALY's. To estimate the number of cases of VL in the population, epidemiological data on prevalence rates were applied to population data. The number of cases of VL was stratified by gender, age, ethnicity, severity and cause. The following sources were used for estimating prevalence: Population-based eye studies; Canadian Surveys; Canadian journal articles and research studies; and International Population Based Eye Studies. Direct health costs were obtained primarily from Health Canada and Canadian Institute for Health Information (CIHI) sources, while costs associated with productivity losses were based on employment information compiled by Statistics Canada and on economic theory of productivity loss. Costs related to vision rehabilitation (VR) were obtained from Canadian VR organizations. This study shows that it is possible to estimate the costs for VL for a country in the absence of ongoing local epidemiological studies. Copyright © 2011 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  20. Assessing color vision loss among solvent-exposed workers.

    Science.gov (United States)

    Mergler, D; Blain, L

    1987-01-01

    Acquired color vision loss has been associated with exposure to organic solvents in the workplace. However, not all tests of chromatic discrimination loss are designed to detect acquired, as opposed to congenital, loss. The Lanthony D-15 desaturated panel (D-15-d), a simple 15 cap color arrangement test, designed to identify mild acquired dyschromatopsia, can be administered rapidly in the field, under standard conditions. The objective of the present study was to evaluate the D-15-d among 23 solvent-exposed workers of a paint manufacturing plant, by comparing the results obtained with the D-15-d to those obtained with the Farnsworth-Munsell 100 Hue (FM-100), a highly sensitive measure of color vision loss. The D-15-d revealed a significantly higher prevalence of dyschromatopsia among the ten highly exposed workers (80%) as compared to the 13 moderately exposed workers (30.8%); FM-100 results revealed one false positive. All dyschromatopic workers presented blue-yellow loss; the FM-100 detected eight complex patterns, while the D-15-d identified 5. Comparison of D-15-d and FM-100 scores were highly correlated (corr. coeff. 0.87; p less than 0.001). Multiple regression analyses showed both scores to be significantly related to age and exposure level. The findings of this study indicate that the D-15-d is an adequate instrument for field study batteries. However, the FM-100 should be used for more detailed assessment.

  1. Keeping Older Adults with Vision Loss Safe: Chronic Conditions and Comorbidities that Influence Functional Mobility

    Science.gov (United States)

    Riddering, Anne T.

    2008-01-01

    Age-related macular degeneration (AMD) is a leading cause of vision loss in Americans aged 60 and older. The loss of central vision from AMD can decrease visual acuity, contrast sensitivity, glare sensitivity, color discrimination, and the ability to adapt to changes in lighting conditions. Older adults with vision loss often have other chronic,…

  2. Management of early loss of first permanent molar: A new technique

    Directory of Open Access Journals (Sweden)

    B S Rajashekhara

    2012-01-01

    Full Text Available The loss of a permanent first molar in adolescent patient creates a need for early space maintenance and restoration of function. To ascertain function and esthetics, immediate treatments include interim restorative approaches. This paper describes a conservative, functional and cost-effective bridge as an interim restoration after the loss of permanent first molar in an early adolescent dentition.

  3. Color vision loss in patients treated with chloroquine

    Directory of Open Access Journals (Sweden)

    Ventura Dora F.

    2003-01-01

    Full Text Available Patients that make use of chloroquine or hydroxychloroquine, drugs which are frequently administered for treatment of rheumatoid arthritis, lupus erithromatosus or malaria, may suffer alterations in color vision and in contrast sensitivity. The present work evaluates the visual function of these patients in a joint study of the University of São Paulo (USP, in São Paulo, and of the Federal University of Pará (UFPA, in Belém. Thirty two chloroquine user patients without alterations in the eye fundus exam were evaluated in São Paulo (n=10; aged 38 to 71 years; mean=55,8 years and in Belém (n=22; aged 20 to 67; mean=40 years. The prescribed accumulated chloroquine dose was 45 to 430 g (mean=213 g; sd = 152 g for the São Paulo group, and 36 to 540 g (mean=174 g; sd=183 g for the Belém group. Tests were performed monocularly with corrected eye refractive state. Color discrimination was evaluated using the Cambridge Colour Test (CCT: the color discrimination threshold was measured first in the protan, deutan and tritan axes and, in succession, three MacAdam's ellipses were determined. The patient's color vision was also evaluated with color arrangement tests: the Farnsworth-Munsell 100 Hue (FM100, the Farnsworth-Munsell D15, and the Lanthony Desaturated (D15d tests. We also measured the contrast sensitivity for black-and-white sine wave grating of twenty two patients. The results were compared with controls without ophthalmologic or neuro-ophthalmologic pathologies. Twenty four patients presented acquired dyschromatopsia. There were cases of selective loss (11 patients and of diffuse loss (13 patients. Although losses were present in the FM100 there was no correlation between the FM100 error score and the ellipse area measured by the CCT. Moreover, three patients that scored normal in the FM100, failed to reach normal threshold in the CCT. The Lanthony test was less sensitive than the other two tests, since it failed to indicate loss in about

  4. Key Informant Perceptions of Vision Loss in Children and ...

    African Journals Online (AJOL)

    tulyasys

    understand how vision can practically be assessed and how poor vision can affect a child, whether by limiting the ability to do activities of daily living or by limiting social interactions. In this group, there were some misconceptions regarding the use of color vision and the assessment of reading as a tool for vision assessment ...

  5. [Early deciduous tooth loss--the mature or immature eruption of their permanent successors].

    Science.gov (United States)

    Czecholinski, J A; Kahl, B; Schwarze, C W

    1994-04-01

    On the basis of 147 panoramic radiographs of 49 patients, this study investigated the influence of the premature loss of deciduous teeth on the formation of their permanent successors at the time of their eruption. Furthermore the study investigated the eruptive movement of the successor teeth at the time of eruption. In addition to detecting the accelerated emergence of still immature successor premolars, the study also determined that the extraction ot the deciduous molars before the age of eight years delayed the eruption of the permanent successors given the absence of an infected deciduous tooth with abscess formation. In relation to the eruptive movement of the permanent molars due to the premature loss of the second deciduous molar, the study ascertained a mesial movement of the first permanent molars and an accelerated eruption of the second permanent molars.

  6. [Correlation between the lower first permanent molar axis and the premature loss of temporary molars].

    Science.gov (United States)

    Petcu, Ana; Maxim, A; Haba, Danisia

    2009-01-01

    The aim of our study was to determine the impact of premature loss of temporary molars upon the longitudinal axis of the first permanent molar. The study sample was formed by 94 orthopanthomografies of child patients with premature loss of lower temporary molars (first or second) after clinical eruption of the first permanent molar. All panoramic radiographs have been realized with the same panoramic unit with 1.4% magnification coefficient and were analyzed using a standardized technique of tracing the images of teeth and bone on matte acetate paper. It was evaluated the angle between longitudinal axis of first permanent lower molar and occlusal plane. It was observed that premature loss of lower second deciduous molar modifies greater the vertical axis of first permanent molar (between 61 degrees and 79 degrees) then premature loss of first lower primary molar. This is perhaps because the loss of space in the case of premature exfoliation of first primary molar is due more to distal drift of canine then mesial drift of molars. The drift to mesial of first permanent molar is more accentuated proportional with the age at which appeared premature loss and so it is loss of leeway space.

  7. The influence of premature loss of temporary upper molars on permanent molars.

    Science.gov (United States)

    Cernei, E R; Maxim, Dana Cristiana; Zetu, Irina Nicoleta

    2015-01-01

    Premature loss of primary molars due to dental caries and their complications has been associated with space loss and eruptive difficulties, especially when the loss occurs early. The aim of our study was to determine the impact of premature loss of temporary upper molars upon the longitudinal axis of the first and second upper permanent molar. The study group included 64 patients 6-9 years old with premature loss of primary molars and a control group of 48 patients with intact temporary teeth. It was evaluated the angle between longitudinal axis of first and second upper permanent molars and occlusal plane. The sofware used is Easy Dent 4 Viewer®.The data were analyzed by using the Statistical Package for the Social Sciences (version 20.0; SPSS, Chicago, III). It was observed that premature loss of upper second deciduous molars modifies greater the vertical axis of the permanent molars than the premature loss of first upper primary molar. First upper primary molar loss cause an acceleration eruption of first premolar, which will produce a distal inclintion of the both permanent molars. The use of space maintainers after premature loss of the second upper temporary molar is a last solution in preventing tridimensional lesions in the dental arch and occlusion.

  8. Loss Investigation of Motor Integrated Permanent Magnet Gear

    DEFF Research Database (Denmark)

    Frandsen, Tommy; Rasmussen, Peter Omand

    2014-01-01

    in urban traffic when compared to state of the art direct drives, even though the measured rotational losses are up to more than 230% higher than estimated with calculations based on 2D FEA. A hypothesis was that large eddy-currents occur in the end-shields of the machine which are made of stainless steel...

  9. Calculation and Analysis of Permanent Magnet Eddy Current Loss Fault with Magnet Segmentation

    Directory of Open Access Journals (Sweden)

    Bing Li

    2016-01-01

    Full Text Available This paper investigates the problem of calculating and analyzing the effect of the permanent magnet eddy current loss fault due to magnet segmentation. Taking an interior permanent magnet synchronous motor with inverter supplied as an example, the rated power of motor was 2.2 kW. Three-dimensional finite-element model was firstly established based on finite-element software. Then, the model mesh and boundary conditions were handled specially; permanent magnet eddy current loss fault was calculated and analyzed theoretically with magnet segmentation from space harmonic and time harmonic, respectively. Finally, calculation results were compared and explained. A useful conclusion for permanent magnet synchronous motor design has been obtained.

  10. Loss of the First Permanent Molar: Risk Factors and Adolescent Oral Health

    OpenAIRE

    Daraí Bárbara Sánchez Montero; Yahima Pons López; Ana Ibis Betancourt García; Anilec Santateresa Marchante

    2017-01-01

    Foundation: the replacement of the primary dentition begins with the eruption of the first permanent molars that will be subjected to various risk factors.Objective: to determine the existing relation between the first permanent molar loss and the risk factors in adolescents from 12 to 14 years old. Method: a cross descriptive study was developed between October 20011 and March 2012. On a universe of 560 students, a simple random sampling was done and a sample of 185 patients was selected. On...

  11. Central and Peripheral Vision Loss Differentially Affects Contextual Cueing in Visual Search

    Science.gov (United States)

    Geringswald, Franziska; Pollmann, Stefan

    2015-01-01

    Visual search for targets in repeated displays is more efficient than search for the same targets in random distractor layouts. Previous work has shown that this contextual cueing is severely impaired under central vision loss. Here, we investigated whether central vision loss, simulated with gaze-contingent displays, prevents the incidental…

  12. Is My World Getting Smaller? The Challenges of Living with Vision Loss

    Science.gov (United States)

    Berger, Sue

    2012-01-01

    Introduction: Vision loss influences both basic and instrumental activities of daily living. There is limited information, however, on the relationship between vision loss and leisure activities. The research presented here was part of a larger study that aimed to understand the importance of participation in leisure activities for those with…

  13. Loss of the First Permanent Molar: Risk Factors and Adolescent Oral Health

    Directory of Open Access Journals (Sweden)

    Daraí Bárbara Sánchez Montero

    2017-02-01

    Full Text Available Foundation: the replacement of the primary dentition begins with the eruption of the first permanent molars that will be subjected to various risk factors.Objective: to determine the existing relation between the first permanent molar loss and the risk factors in adolescents from 12 to 14 years old. Method: a cross descriptive study was developed between October 20011 and March 2012. On a universe of 560 students, a simple random sampling was done and a sample of 185 patients was selected. On school visits dental exams were performed to determine the Clune index dental caries index, filled and missing teeth and the simplified index of oral hygiene. The estimated relative risk was used with prevalence odd ratio and prevalence ratio was calculated. The studied variables were: sex, oral hygiene habits, and habits of cariogenic diet bucodental health. Results: the loss of the first permanent molar predominated in the male sex with a 14.1 %. The prevailing risk factor was cariogenic diet which affected 57.3 of the population, where 80.6 of those who had a high consumption showed loss of the first permanent molar. Clune index (53,4 % in the female and 40 % in the male sex, dental caries, filled and lost teeth (1.7 % in female and 2.9 in the male sex were calculated. Conclusion: there is a direct relation between risk factors, poor oral hygiene and cariogenic feeding with the loss of the first permanent molar.

  14. Effect of premature loss of deciduous canines and molars on malocclusion of the permanent dentition.

    Science.gov (United States)

    Miyamoto, W; Chung, C S; Yee, P K

    1976-01-01

    The effect of the premature loss of deciduous canines and first and second molars on malocclusion of the permanent dentition was studied in 255 schoolchildren 11 years of age or older at the most recent examination of the permanent dentition. Malocclusion was evaluated by scoring malalignment (major and minor) and measurement of crowding in the anterior teeth. Children who had a premature loss of one or more canines or molars had a higher frequency of receiving orthodontic treatment of one type or another for the permanent dentition. The likelihood of need of treatment increased with the number of prematurely lost teeth. Children who had lost one or more deciduous teeth through age 9 had a greater than threefold increase in the frequency of orthodontic treatment relative to the control. Of those who did not receive orthodontic treatment, there was no detectable relationship of the premature loss of canines with the malalignment of permanent teeth. However, there was a significant effect of the premature extraction of molars on malalignment especially major malalignment of permanent teeth. No differences were noted in their effects between the first and second deciduous molars. Crowding of the anterior teeth was directly affected by the premature loss of deciduous canines.

  15. Role of vision loss, functional limitations and the supporting network in depression in a general population.

    Science.gov (United States)

    van Nispen, Ruth M A; Vreeken, Hilde L; Comijs, Hannie C; Deeg, Dorly J H; van Rens, Ger H M B

    2016-02-01

    Although the prevalence of depression in visually impaired older persons is high, the association between vision loss and depression seems to be influenced by factors other than visual impairment. In this study, the role of vision loss, functional limitations and social network characteristics in relation to depressive symptoms was investigated. Cross-sectional data (N = 1237) from the Longitudinal Aging Study Amsterdam were used to investigate the prevalence of depression (Center of Epidemiological Studies-Depression scale) within subgroups with increasing vision loss. In linear regression models, functional limitations and social network characteristics were examined as possible mediators in the association between vision loss and depression. Having a partner was considered to be a potential moderator. Although a significant linear trend was found in the presence of depressive symptoms with 14% in normally sighted, 23% in mild and 37% in severe vision loss (χ(2)(1) = 14.9; p depression. Mediators were functional limitations (p depression, a trend was found with increasing severity of vision loss, indicating the need for more attention in (mental) health care and low-vision rehabilitation. In the general older population, vision loss was not an independent determinant of depression but was mediated by functional limitations and social network size. Rather than receiving actual social support, the idea of having a social network to rely on when needed seemed to be associated with lower levels of depression. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  16. Eddy current loss calculation and thermal analysis of axial-flux permanent magnet couplers

    Directory of Open Access Journals (Sweden)

    Di Zheng

    2017-02-01

    Full Text Available A three-dimensional magnetic field analytical model of axial-flux permanent magnet couplers is presented to calculate the eddy current loss, and the prediction of the copper plate temperature under various loads is analyzed. The magnetic field distribution is calculated, and then the eddy current loss is obtained, with the magnetic field analytical model established in cylindrical coordinate. The influence of various loads on eddy current loss is analyzed. Furthermore, a thermal model of axial-flux permanent magnet couplers is established by taking the eddy current loss as the heat source, using the electromagnetic-thermal coupled method. With the help of the thermal model, the influence of various loads on copper plate temperature rise is also analyzed. The calculated results are compared with the results of finite element method and measurement. The comparison results confirm the validity of the magnetic field analytical model and thermal model.

  17. Practical Investigation of End Effect Losses in a Motor Integrated Permanent Magnet Gear

    DEFF Research Database (Denmark)

    Frandsen, Tommy Vestergaard; Rasmussen, Peter Omand

    2015-01-01

    to reduce 3D eddy currents in the machine. Material is removed and new parts are made in a non-conducting material. After the modifications of the prototype, the rotational losses have been measured and compared to the earlier measurements and the 2D based calculated losses. The rotational losses have been......This paper presents a practical investigation of the eddy current losses caused by 3D effects in a Motor Integrated Permanent Magnet Gear (MIPMG). Two prototypes of a MIPMG have been designed and build to be used as traction units for an electric vehicle. The measured efficiency of the prototype...

  18. effect of number of rotor poles on ac losses of permanent magnet

    African Journals Online (AJOL)

    HOD

    A study on permanent magnet (PM) eddy current and core losses of dual-stator PM machines is investigated in this paper. ... material in the retaining sleeves of surface-mounted ... rotor-pole numbers (13-poleand 14-pole in particular) ... Table 2: Optimized Machine Parameters. Number of rotor poles. 4. 5. 7. 8. 10. 11. 13. 14.

  19. AXIAL MODIFICATIONS OF PERMANENT LOWER MOLARS AFTER PREMATURE LOSSES OF TEMPORARY MOLARS.

    Science.gov (United States)

    Cernei, E R; Mavru, R B; Zetu, Irina Nicoleta

    2016-01-01

    The aim of our study was to determine the impact of premature loss of temporary lower molars upon the longitudinal axis of the first and second permanent molars. The study groups included 61 patients, 6-9 year olds with premature loss of primary molars and a control group of 24 patients with intact temporary teeth. We evaluated the angle between longitudinal axis of first and second lower permanent molars and occlusal plane. It was observed that premature loss of lower second deciduous molar modifies more the vertical axis of first and second permanent molars than the premature loss of first lower primary molar. Reducing space occurs mainly through mesial inclination of molars that separates the edentulous breach. Temporary loss of both lower first molars on the same quadrant causes an accelerated eruption of both premolars increasing the prevalence of eruption sequence: "4-5-3-7". The preservation of the occlusal morpho-functional complex using space maintainers mainly when the premature loss of the second primary molars occurs is the best interceptive treatment option.

  20. Prevalence of vision loss among hospital in-patients; a risk factor for falls?

    Science.gov (United States)

    Leat, Susan J; Zecevic, Aleksandra A; Keeling, Alexis; Hileeto, Denise; Labreche, Tammy; Brymer, Christopher

    2018-01-01

    Despite poor vision being a risk factor for falls, current hospital policies and practices often do not include a vision assessment at patient admission or in the hospital's incident reporting system when a fall occurs. Our purpose was to document the prevalence of vision loss in hospital general medicine units to increase awareness of poor vision as a potential risk factor for falls that occur within the hospital, and inform future preventative practice. This cross-sectional study took place in medicine units of an acute care hospital. Participants were adult in-patients. Visual acuity (VA), contrast sensitivity and stereoacuity were measured, and patients were screened for field loss, extinction and neglect. 115 participants took part (average age 67 ± 17, 48% female). Overall, 89% had a visual impairment defined as being outside the age-norms for one or more vision measure, 62% had low vision, and 36% had vision loss equivalent to legal blindness [VA equal to or poorer than 1.0 logMAR (6/60, 20/200) or ≥10x below age-norms]. There was a considerable discrepancy between the prevalence of low vision and the percentage of patients who reported an ocular diagnosis that would result in visual loss (30%). Ten patients fell during the study period, and of these 100% had visual impairment, 90% had low vision and 60% had vision loss equivalent to legal blindness, which compares to 58%, 22% and 9% for non-fallers. Similar high prevalences were found in those whose reason for admission to the hospital was a fall (92%, 63% and 33% respectively). Vision loss has a high prevalence among patients in hospital medicine units, and is higher still among those who fall. Since vision loss may be a contributing factor to falls that occur in hospitals, implementing an assessment of vision at hospital admission would be useful to alert staff to those patients who are at risk for falls due to poor vision, so that preventative measures can be applied. © 2017 The Authors Ophthalmic

  1. The Functional Classification of Brain Damage-Related Vision Loss

    Science.gov (United States)

    Colenbrander, August

    2009-01-01

    This article provides a terminological framework to show the relationships among different types of visual deficits. It distinguishes between visual functions, which describe how the eye and the lower visual system function, and functional vision, which describes how a person functions. When visual functions are disturbed, the term "visual…

  2. Peritoneal transport in CAPD patients with permanent loss of ultrafiltration capacity

    International Nuclear Information System (INIS)

    Heimbuerger, O.W.; Waniewski, J.; Werynski, A.; Tranaeus, A.; Lindholm, B.

    1990-01-01

    During a 10 year period, 14 out of 227 patients (6.2%) undergoing continuous ambulatory peritoneal dialysis (CAPD) developed permanent loss of ultrafiltration capacity (UFC). The risk of UFC loss increased from 2.6% after one year to 30.9% after six years of treatment. A six hour, single dwell study with glucose 3.86% dialysis fluid was carried out in nine of the UFC loss patients and in 18 CAPD patients with normal UFC. Intraperitoneal dialysate volumes were calculated using 131I-tagged albumin (RISA) as volume marker with a correction applied for its elimination from the peritoneal cavity. The RISA elimination coefficient (KE), which can serve as an estimation of the upper limit of the lymphatic flow, was also calculated. Diffusive mass transport coefficients (KBD) for investigated solutes (glucose, creatinine, urea, potassium, total protein, albumin and beta 2-microglobulin) were calculated during a period of dialysate isovolemia. Two patterns of UFC loss were observed: (a) seven patients had high KBD values for small solutes resulting in rapid uptake of glucose, whereas KBD values for proteins were normal; (b) two patients had normal KBD values but a threefold increase both in the fluid reabsorption rate and KE. We conclude that loss of the osmotic driving force (due to increased diffusive mass transport for small solutes) and increased fluid reabsorption (possibly due to increased lymphatic reabsorption) are the two major causes of permanent loss of UFC in CAPD patients

  3. Loss measurement and analysis for the prototype generator with HTS stator and permanent magnet rotor

    Energy Technology Data Exchange (ETDEWEB)

    Song, Peng, E-mail: songp10@mails.tsinghua.edu.cn [Applied Superconductivity Research Center, Department of Physics, Tsinghua University, Beijing 100084 (China); Qu, Timing, E-mail: tmqu@mail.tsinghua.edu.cn [Applied Superconductivity Research Center, Department of Physics, Tsinghua University, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); Yu, Xiaoyu [Department of Mechanical Engineering, Tsinghua University, Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); Li, Longnian; Gu, Chen [Applied Superconductivity Research Center, Department of Physics, Tsinghua University, Beijing 100084 (China); Li, Xiaohang [Innova Superconductor Technology Co., Ltd., Beijing 100084 (China); Wang, Dewen; Hu, Boping [Beijing Zhong Ke San Huan Hi-Tech Co., Ltd., Beijing 100084 (China); Chen, Duxing [Department Fis, University Autonoma Barcelona, Barcelona 08193 (Spain); Han, Zhenghe [Applied Superconductivity Research Center, Department of Physics, Tsinghua University, Beijing 100084 (China)

    2013-11-15

    Highlights: •A novel prototype HTS generator with HTS armature windings was developed. •No-load loss and the iron loss at low temperature were measured. •The total loss at low temperature is much larger than the room temperature case. •The reason for no-load loss increment at low temperature is discussed. -- Abstract: A prototype HTS synchronous generator with a permanent magnet rotor and HTS armature windings was developed. The rated armature frequency is 10 Hz. The cryogenic Dewar is tightly surrounded outside the iron core. Both HTS coils and the iron core were cooled by using conduction cooling method. During the process of no-load running, the no-load loss power data were obtained through the torque measurement. The temperature evolution characteristics of the stator was measured by PT-100 temperature sensors. These results show that the no-load loss power at around 77 K are much larger than that at room temperature. The possible reason for the no-load loss increment is discussed. The ac loss power of one individual HTS coil used in this generator was also tested. Compared with the iron loss power, the ac loss power is rather small and could be neglected.

  4. Profound vision loss impairs psychological well-being in young and middle-aged individuals.

    Science.gov (United States)

    Garcia, Giancarlo A; Khoshnevis, Matin; Gale, Jesse; Frousiakis, Starleen E; Hwang, Tiffany J; Poincenot, Lissa; Karanjia, Rustum; Baron, David; Sadun, Alfredo A

    2017-01-01

    The aim of this study was to evaluate the effects of profound vision loss on psychological well-being in adolescents, young adults, and middle-aged adults with regard to mood, interpersonal interactions, and career-related goals. In addition, we assessed the significance of the resources that may be used to enhance psychological well-being in cases of profound vision loss, and in particular, examined the utility of low vision aids and the role of the ophthalmologist as a provider of emotional support. A questionnaire was issued to individuals aged 13-65 years with profound vision loss resulting from Leber's hereditary optic neuropathy (LHON). Depression prevalence was evaluated with questions regarding major depressive disorder symptomatology. Participants appraised the effects of vision loss on their interpersonal interactions and career goals by providing an impact rating (IR) on a 21-point psychometric scale from -10 to +10. Social well-being index was defined as the average of interpersonal IR and career IR. Subjects were additionally asked about the use of low vision aids and sources of emotional support. A total of 103 participants (mean age =26.4±11.2 years at LHON diagnosis; mean ± standard deviation) completed the questionnaire. Nearly half (49.5%) met the depression criteria after vision loss. Negative impacts on interpersonal interactions (median IR = -5) and career goals (median IR = -6) were observed; both ratings were worse ( P negative interpersonal IR and career IR. Sixty-eight percent of subjects used electronic vision aids; controlling for age, social well-being index was higher among these individuals than for those who did not use electronic aids ( P =0.03). Over half of the participants (52.4%) asserted that they derived emotional support from their ophthalmologist. Profound vision loss in adolescents, young adults, and middle-aged adults is associated with significant negative psychological and psychosocial effects, which are influenced by

  5. The prevalence of vision loss due to ocular trauma in the Australian National Eye Health Survey.

    Science.gov (United States)

    Keel, Stuart; Xie, Jing; Foreman, Joshua; Taylor, Hugh R; Dirani, Mohamed

    2017-11-01

    To determine the prevalence of vision loss due to ocular trauma in Australia. The National Eye Health Survey (NEHS) is a population-based cross-sectional study that examined 3098 non-Indigenous Australians (aged 50-98 years) and 1738 Indigenous Australians (aged 40-92 years) living in 30 randomly selected sites, stratified by remoteness. An eye was considered to have vision loss due to trauma if the best-corrected visual acuity was worse than 6/12 and the main cause was attributed to ocular trauma. This determination was made by two independent ophthalmologists and any disagreements were adjudicated by a third senior ophthalmologist. The sampling weight adjusted prevalence of vision loss due to ocular trauma in non-Indigenous Australians aged 50 years and older and Indigenous Australians aged 40 years and over was 0.24% (95%CI: 0.10, 0.52) and 0.79% (95%CI: 0.56, 1.13), respectively. Trauma was attributed as an underlying cause of bilateral vision loss in one Indigenous participant, with all other cases being monocular. Males displayed a higher prevalence of vision loss from ocular trauma than females in both the non-Indigenous (0.47% vs. 1.25%, p=0.03) and Indigenous populations (0.12% vs. 0.38%, p=0.02). After multivariate adjustments, residing in Very Remote geographical areas was associated with higher odds of vision loss from ocular trauma. We estimate that 2.4 per 1000 non-Indigenous and 7.9 per 1000 Indigenous Australian adults have monocular vision loss due to a previous severe ocular trauma. Our findings indicate that males, Indigenous Australians and those residing in Very Remote communities may benefit from targeted health promotion to improve awareness of trauma prevention strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Evaluation of Iron Loss in Interior Permanent Magnet Synchronous Motor with Consideration of Rotational Field

    Science.gov (United States)

    Ma, Lei; Sanada, Masayuki; Morimoto, Shigeo; Takeda, Yoji; Kaido, Chikara; Wakisaka, Takeaki

    Loss evaluation is an important issue in the design of electrical machines. Due to the complicate structure and flux distribution, it is difficult to predict the iron loss in the machines exactly. This paper studies the iron loss in interior permanent magnet synchronous motors based on the finite element method. The iron loss test data of core material are used in the fitting of the hysteresis and eddy current loss constants. For motors in practical operation, additional iron losses due to the appearance of rotation of flux density vector and harmonic flux density distribution makes the calculation data deviates from the measured ones. Revision is made to account for these excess iron losses which exist in the practical operating condition. Calculation results show good consistence with the experimental ones. The proposed method provides a possible way to predict the iron loss of the electrical machine with good precision, and may be helpful in the selection of the core material which is best suitable for a certain machine.

  7. Permanent tooth loss and sugar-sweetened beverage intake in U.S. young adults.

    Science.gov (United States)

    Kim, Sunkyung; Park, Sohyun; Lin, Mei

    2017-03-01

    In young adults, sugar-sweetened beverage (SSB) intake is associated with dental caries, which in turn is a major contributor to tooth loss. The independent role of SSB intake on tooth loss, however, has not been well-described. This cross-sectional study examined associations between tooth loss and SSB intake among U.S. young adults. The outcome was number of permanent teeth lost because of dental caries or periodontal disease (0, 1-5, ≥6 teeth). Data from the 2012 Behavioral Risk Factor Surveillance System were used. The 22,526 adults aged 18-39 years completed the Sugar Drink Module. The exposure variable was daily frequency of SSB intake. We used multinomial logistic regression to examine the adjusted associations between tooth loss and daily SSB consumption (0, >0 to 2 times/day). Approximately, 26% of young adults reported losing at least one permanent tooth. Tooth loss was positively associated with SSB intake frequency; the odds of losing 1-5 teeth were higher among adults drinking SSBs >0-2 times/day (OR = 1.97, 95%CI = 1.51-2.58) than non-SSB consumers. The odds of losing ≥6 teeth were higher among adults drinking SSBs 1-2 times/day (OR = 2.20, 95%CI = 1.15-4.22) and >2 times/day (OR = 2.81, 95%CI = 1.37-5.76) than non-SSB consumers. Frequency of SSB consumption was positively associated with tooth loss among young adults even when the average SSB intake was less than one time per day. This study suggests that efforts to reduce SSB intake among young adults may help to decrease the risk of tooth loss. © 2016 American Association of Public Health Dentistry.

  8. Origins of strabismus and loss of binocular vision

    Science.gov (United States)

    Bui Quoc, Emmanuel; Milleret, Chantal

    2014-01-01

    Strabismus is a frequent ocular disorder that develops early in life in humans. As a general rule, it is characterized by a misalignment of the visual axes which most often appears during the critical period of visual development. However other characteristics of strabismus may vary greatly among subjects, for example, being convergent or divergent, horizontal or vertical, with variable angles of deviation. Binocular vision may also vary greatly. Our main goal here is to develop the idea that such “polymorphy” reflects a wide variety in the possible origins of strabismus. We propose that strabismus must be considered as possibly resulting from abnormal genetic and/or acquired factors, anatomical and/or functional abnormalities, in the sensory and/or the motor systems, both peripherally and/or in the brain itself. We shall particularly develop the possible “central” origins of strabismus. Indeed, we are convinced that it is time now to open this “black box” in order to move forward. All of this will be developed on the basis of both presently available data in literature (including most recent data) and our own experience. Both data in biology and medicine will be referred to. Our conclusions will hopefully help ophthalmologists to better understand strabismus and to develop new therapeutic strategies in the future. Presently, physicians eliminate or limit the negative effects of such pathology both on the development of the visual system and visual perception through the use of optical correction and, in some cases, extraocular muscle surgery. To better circumscribe the problem of the origins of strabismus, including at a cerebral level, may improve its management, in particular with respect to binocular vision, through innovating tools by treating the pathology at the source. PMID:25309358

  9. Premature loss of primary teeth: part I, its overall effect on occlusion and space in the permanent dentition.

    Science.gov (United States)

    Hoffding, J; Kisling, E

    1978-01-01

    Premature loss of primary molars causes, without doubt, permanent changes in regard to space and sagittal molar relations, in the permanent dentition. The changes are due to drifting of teeth and lack of growth, and such changes should, whenever possible, be prevented. In part two of this series of papers, a further analysis of the data will be presented.

  10. Profound vision loss impairs psychological well-being in young and middle-aged individuals

    Directory of Open Access Journals (Sweden)

    Garcia GA

    2017-02-01

    Full Text Available Giancarlo A Garcia,1,2 Matin Khoshnevis,1,3 Jesse Gale,1,4 Starleen E Frousiakis,1,5 Tiffany J Hwang,1,6 Lissa Poincenot,1 Rustum Karanjia,1,7–9 David Baron,6 Alfredo A Sadun1,7 1Doheny Eye Institute, Los Angeles, CA, USA; 2University of California, Irvine School of Medicine, Irvine, CA, USA; 3Department of Ophthalmology, Temple University, Philadelphia, PA, USA; 4Wellington School of Medicine and Health Sciences, University of Otago, Wellington, NZ; 5Department of Ophthalmology, New York Medical College, Valhalla, NY, USA; 6Department of Psychiatry & The Behavioral Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; 7Doheny Eye Centers, Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles California, CA, USA; 8Department of Ophthalmology, University of Ottawa, Ottawa, ON, Canada; 9Ottawa Hospital Health Research Institute, Ottawa, ON, Canada Purpose: The aim of this study was to evaluate the effects of profound vision loss on psychological well-being in adolescents, young adults, and middle-aged adults with regard to mood, interpersonal interactions, and career-related goals. In addition, we assessed the significance of the resources that may be used to enhance psychological well-being in cases of profound vision loss, and in particular, examined the utility of low vision aids and the role of the ophthalmologist as a provider of emotional support.Methods: A questionnaire was issued to individuals aged 13–65 years with profound vision loss resulting from Leber’s hereditary optic neuropathy (LHON. Depression prevalence was evaluated with questions regarding major depressive disorder symptomatology. Participants appraised the effects of vision loss on their interpersonal interactions and career goals by providing an impact rating (IR on a 21-point psychometric scale from −10 to +10. Social well-being index was defined as the average of interpersonal IR and career IR

  11. Neurogenic vision loss: Causes and outcome. An experience from a tertiary center in Northern India

    Directory of Open Access Journals (Sweden)

    Rajesh Verma

    2014-01-01

    Full Text Available Introduction: Vision loss can be a consequence of numerous disorders of eye and neural pathway conveying visual input to brain. A variety of conditions can affect visual pathway producing neurogenic vision loss. The presentation and course of vision loss depends on the site of involvement and underlying etiology. We conducted this unprecedented study to evaluate the characteristics and outcome of various diseases of the visual pathway. Materials and Methods: In this prospective cohort study, we evaluated 64 patients with neurogenic visual impairment. Ophthalmological causes were excluded in all of them. Their presentation, ophthalmological characteristics and investigation findings were recorded. These patients were followed up till 6 months. Results: Out of 69 patients evaluated, 5 were excluded as they had ophthalmological abnormalities. The remaining 64 cases (113 eyes were enrolled. 54 cases were due to diseases of anterior visual pathway and rest 10 had cortical vision loss. The etiologic distribution is as follows: Isolated optic neuritis- 12 (19%, multiple sclerosis- 4 (6.3%, neuromyelitis optica- 5 (7.9%, tubercular meningitis- 15 (23.8%, non-arteritic ischemic optic neuropathy, ischemic optic neuropathy complicating cavernous sinus thrombosis, cryptococcal meningitis, malignant infiltration of optic nerve, Crouzon′s syndrome, calvarial thickening and traumatic occipital gliosis- 1 (1.6% case each, idiopathic intracranial hypertension, pituitary adenoma, acute disseminated encephalomyelitis, posterior reversible leukoencephalopathy- 3 (4.8% cases each, cortical venous thrombosis 5 (7.9%, subacute scleroing panencephalitis- 4 (6.3% cases. Conclusions: The diseases of anterior visual pathway were much more common than cortical vision loss. A majority of our patients had severe impairment of vision at presentation.

  12. Loss evaluation and design optimisation for direct driven permanent magnet synchronous generators for wind power

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Sandra; Bernhoff, Hans [Swedish Centre for Renewable Electric Energy Conversion, Division for Electricity, Department of Engineering Sciences, Uppsala University, Box 534, 751 21 Uppsala (Sweden)

    2011-01-15

    When designing a generator for a wind turbine it is important to adapt the generator to the source, i.e. the wind conditions at the specific site. Furthermore, the variable speed operation of the generator needs to be considered. In this paper, electromagnetic losses in direct driven permanent magnet synchronous generators are evaluated through simulations. Six different generators are compared to each other. The simulations are performed by using an electromagnetic model, solved in a finite element environment and a control model developed in MATLAB. It is shown that when designing a generator it is important to consider the statistical wind distribution, control system, and aerodynamic efficiency in order to evaluate the performance properly. In this paper, generators with high overload capability are studied since they are of interest for this specific application. It is shown that a generator optimised for a minimum of losses will have a high overload capability. (author)

  13. Estimation of the iron loss in deep-sea permanent magnet motors considering seawater compressive stress.

    Science.gov (United States)

    Xu, Yongxiang; Wei, Yanyu; Zou, Jibin; Li, Jianjun; Qi, Wenjuan; Li, Yong

    2014-01-01

    Deep-sea permanent magnet motor equipped with fluid compensated pressure-tolerant system is compressed by the high pressure fluid both outside and inside. The induced stress distribution in stator core is significantly different from that in land type motor. Its effect on the magnetic properties of stator core is important for deep-sea motor designers but seldom reported. In this paper, the stress distribution in stator core, regarding the seawater compressive stress, is calculated by 2D finite element method (FEM). The effect of compressive stress on magnetic properties of electrical steel sheet, that is, permeability, BH curves, and BW curves, is also measured. Then, based on the measured magnetic properties and calculated stress distribution, the stator iron loss is estimated by stress-electromagnetics-coupling FEM. At last the estimation is verified by experiment. Both the calculated and measured results show that stator iron loss increases obviously with the seawater compressive stress.

  14. Estimation of the Iron Loss in Deep-Sea Permanent Magnet Motors considering Seawater Compressive Stress

    Directory of Open Access Journals (Sweden)

    Yongxiang Xu

    2014-01-01

    Full Text Available Deep-sea permanent magnet motor equipped with fluid compensated pressure-tolerant system is compressed by the high pressure fluid both outside and inside. The induced stress distribution in stator core is significantly different from that in land type motor. Its effect on the magnetic properties of stator core is important for deep-sea motor designers but seldom reported. In this paper, the stress distribution in stator core, regarding the seawater compressive stress, is calculated by 2D finite element method (FEM. The effect of compressive stress on magnetic properties of electrical steel sheet, that is, permeability, BH curves, and BW curves, is also measured. Then, based on the measured magnetic properties and calculated stress distribution, the stator iron loss is estimated by stress-electromagnetics-coupling FEM. At last the estimation is verified by experiment. Both the calculated and measured results show that stator iron loss increases obviously with the seawater compressive stress.

  15. Identification of some additional loss components in high-power low-voltage permanent magnet generators

    Energy Technology Data Exchange (ETDEWEB)

    Hamalainen, H.

    2013-11-01

    Permanent magnet generators (PMG) represent the cutting edge technology in modern wind mills. The efficiency remains high (over 90%) at partial loads. To improve the machine efficiency even further, every aspect of machine losses has to be analyzed. Additional losses are often given as a certain percentage without providing any detailed information about the actual calculation process; meanwhile, there are many design-dependent losses that have an effect on the total amount of additional losses and that have to be taken into consideration. Additional losses are most often eddy current losses in different parts of the machine. These losses are usually difficult to calculate in the design process. In this doctoral thesis, some additional losses are identified and modeled. Further, suggestions on how to minimize the losses are given. Iron losses can differ significantly between the measured no-load values and the loss values under load. In addition, with embedded magnet rotors, the quadrature-axis armature reaction adds losses to the stator iron by manipulating the harmonic content of the flux. It was, therefore, re-evaluated that in salient pole machines, to minimize the losses and the loss difference between the no-load and load operation, the flux density has to be kept below 1.5 T in the stator yoke, which is the traditional guideline for machine designers. Eddy current losses may occur in the end-winding area and in the support structure of the machine, that is, in the finger plate and the clamping ring. With construction steel, these losses account for 0.08% of the input power of the machine. These losses can be reduced almost to zero by using nonmagnetic stainless steel. In addition, the machine housing may be subjected to eddy current losses if the flux density exceeds 1.5 T in the stator yoke. Winding losses can rise rapidly when high frequencies and 10-15 mm high conductors are used. In general, minimizing the winding losses is simple. For example, it can be

  16. Low Vision Devices and Training

    Directory of Open Access Journals (Sweden)

    Imran Azam Butt

    2004-01-01

    Full Text Available Vision is the ability to see with a clear perception of detail, colour and contrast, and to distinguish objects visually. Like any other sense, vision tends to deteriorate or diminish naturally with age. In most cases, reduction in visual capability can be corrected with glasses, medicine or surgery. However, if the visual changes occur because of an incurable eye disease, condition or injury, vision loss can be permanent. Many people around the world with permanent visual impairment have some residual vision which can be used with the help of low vision services, materials and devices. This paper describes different options for the enhancement of residual vision including optical and non-optical devices and providing training for the low vision client.

  17. [Ocular myositis as a rare cause of vision loss].

    Science.gov (United States)

    Rollnik, J D; Requadt, H

    2017-04-01

    Ocular myositis is a rare disease characterized by painful diplopia but loss of vision rarely occurs. The article reviews the literature focusing on the differential diagnostics. We report the case of an 80-year-old women suffering from slowly progressive loss of vision in the left eye. Diplopia was only present at the beginning and there was only moderate pain. Computed tomography and magnetic resonance imaging revealed a swelling of the left medial, lateral and inferior rectus muscles of the orbit leading to compression of the optic nerve in the orbital cone. An intravenous prednisolone stoss therapy (1000 mg per day for 3 consecutive days) was initiated, followed by oral medication of 100 mg per day then tapering over 10 weeks. Vision improved and no relapses were observed. Physicians should be aware of this rare disease to ensure quick diagnosis and treatment of ocular myositis.

  18. Bilateral idiopathic optic perineuritis with severe vision loss: A case report

    Directory of Open Access Journals (Sweden)

    Wee-Min Teh

    2015-07-01

    Full Text Available Optic perineuritis is an orbital inflammatory disorder that is either idiopathic or secondary to other conditions such as infection or systemic inflammatory disorders. This condition is very similar to demyelinating optic neuritis, but certain features of the history and magnetic resonance imaging findings are characteristic for and aid in the diagnosis of optic perineuritis. Vision loss varies greatly, from minimal clouding of vision up to only light perception. We report a case of a 44-year-old female with idiopathic bilateral optic perineuritis with vision loss of up to no light perception in both eyes. Radio imaging studies were typical of optic perineuritis and she was started on systemic corticosteroids. She responded very well to steroid therapy and achieved nearly complete visual recovery. There had been no relapse despite cessation of therapy.

  19. Vision loss associated with the use and removal of intraocular silicone oil

    Directory of Open Access Journals (Sweden)

    Patrick D Williams

    2009-02-01

    Full Text Available Patrick D Williams1, Christopher G Fuller1, Ingrid U Scott2, Dwain G Fuller1, Harry W Flynn Jr31Texas Retina Associates, Dallas, TX, USA; 2Departments of Ophthalmology and Health Evaluation Sciences, Penn State College of Medicine, Hershey, PA, USA; 3Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USAPurpose: To describe vision loss associated with the use or removal of silicone oil retinal tamponade.Methods: Records were reviewed of all patients with a decrease in visual acuity of at least 3 Snellen lines from best acuity with 5000 centistoke silicone oil in place or after removal of silicone oil at a single retina-only practice between 1996 and 2006.Results: Nine patients (6 men, 3 women with a mean age of 48 years (range, 16–61 met study inclusion criteria. Seven patients lost at least three Snellen lines of vision while the silicone oil was in place. Four patients had late modest improvements in acuity when compared to their final recorded Snellen vision before silicone oil removal, however no patients exhibited visual improvement when comparing their final recorded visual acuities after oil removal with best recorded acuities under oil tamponade. Loss of the foveal depression was a consistent feature on optical coherence tomography.Conclusions: Vision loss is a possible complication of silicone oil use and removal. Late visual improvement may occur in some patients. Further research is warranted to elucidate the mechanism(s of vision loss associated with the use or removal of silicone oil.Keywords: retinal tamponade, visual acuity, snellen vision, silicone oil

  20. Developmental Regulation with Progressive Vision Loss: Use of Control Strategies and Affective Well-Being

    Science.gov (United States)

    Schilling, Oliver K.; Wahl, Hans-Werner; Boerner, Kathrin; Horowitz, Amy; Reinhardt, Joann P.; Cimarolli, Verena R.; Brennan-Ing, Mark; Heckhausen, Jutta

    2016-01-01

    The present study addresses older adults' developmental regulation when faced with progressive and irreversible vision loss. We used the motivational theory of life span development as a conceptual framework and examined changes in older adults' striving for control over everyday goal achievement, and their association with affective well-being,…

  1. Acute loss of vision in a young woman: A case report on ...

    African Journals Online (AJOL)

    Background: Acute loss of vision needs urgent attention and treatment. We report on a young Ethiopian woman who experienced acute bilateral blindness. In the presence of normal ophthalmological findings psychogenic blindness has to be considered. Case Details: A 21 years old woman was admitted to the psychiatry ...

  2. Muller cell-specific autoantibodies in a patient with progressive loss of vision

    NARCIS (Netherlands)

    Peek, R.; Verbraak, F.; Coevoet, H. M.; Kijlstra, A.

    1998-01-01

    PURPOSE. To study the specificity of circulating retinal autoantibodies in a patient with progressive loss of vision resembling cancer-associated retinopathy in the absence of systemic malignancy. METHODS. Patient's serum was tested for the presence of antiretinal antibodies by Western blot

  3. Dural metastasis from prostatic adenocarcinoma mimicking meningioma: Report of a case with unilateral loss of vision

    International Nuclear Information System (INIS)

    Tokgoz, Ozlem; Voyvoda, Nuray; Tokgoz, Husnu

    2011-01-01

    We report a case of PCa (prostatic adenocarcinoma) with transdural metastasis which radiologically simulated a meningioma. During the course of the disease, the patient complained of progressive unilateral loss of vision as the first presentation of intracranial, extra-axial metastasis

  4. Adjustment to acquired vision loss in adults presenting for visual disability certification.

    Science.gov (United States)

    Nakade, Aditya; Rohatgi, Jolly; Bhatia, Manjeet S; Dhaliwal, Upreet

    2017-03-01

    Rehabilitation of the visually disabled depends on how they adjust to loss; understanding contributing factors may help in effective rehabilitation. The aim of this study is to assess adjustment to acquired vision loss in adults. This observational study, conducted in the Department of Ophthalmology at a tertiary-level teaching hospital, included thirty persons (25-65 years) with visual disability, might contribute to reducing stress and depression.

  5. Loss of binocular vision as direct cause for misrouting of temporal retinal fibers in albinism.

    Science.gov (United States)

    Banihani, Saleh M

    2015-10-01

    In humans, the nasal retina projects to the contralateral hemisphere, whereas the temporal retina projects ipsilaterally. The nasotemporal line that divides the retina into crossed and uncrossed parts coincides with the vertical meridian through the fovea. This normal projection of the retina is severely altered in albinism, in which the nasotemporal line shifted into the temporal retina with temporal retinal fibers cross the midline at the optic chiasm. This study proposes the loss of binocular vision as direct cause for misrouting of temporal retinal fibers and shifting of the nasotemporal line temporally in albinism. It is supported by many observations that clearly indicate that loss of binocular vision causes uncrossed retinal fibers to cross the midline. This hypothesis may alert scientists and clinicians to find ways to prevent or minimize the loss of binocular vision that may occur in some diseases such as albinism and early squint. Hopefully, this will minimize the misrouting of temporal fibers and improve vision in such diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Patterns of functional vision loss in glaucoma determined with archetypal analysis

    Science.gov (United States)

    Elze, Tobias; Pasquale, Louis R.; Shen, Lucy Q.; Chen, Teresa C.; Wiggs, Janey L.; Bex, Peter J.

    2015-01-01

    Glaucoma is an optic neuropathy accompanied by vision loss which can be mapped by visual field (VF) testing revealing characteristic patterns related to the retinal nerve fibre layer anatomy. While detailed knowledge about these patterns is important to understand the anatomic and genetic aspects of glaucoma, current classification schemes are typically predominantly derived qualitatively. Here, we classify glaucomatous vision loss quantitatively by statistically learning prototypical patterns on the convex hull of the data space. In contrast to component-based approaches, this method emphasizes distinct aspects of the data and provides patterns that are easier to interpret for clinicians. Based on 13 231 reliable Humphrey VFs from a large clinical glaucoma practice, we identify an optimal solution with 17 glaucomatous vision loss prototypes which fit well with previously described qualitative patterns from a large clinical study. We illustrate relations of our patterns to retinal structure by a previously developed mathematical model. In contrast to the qualitative clinical approaches, our results can serve as a framework to quantify the various subtypes of glaucomatous visual field loss. PMID:25505132

  7. Cardiorespiratory fitness and vision loss among young and middle-age U.S. adults.

    Science.gov (United States)

    Loprinzi, Paul D; Zebardast, Nazlee; Ramulu, Pradeep Y

    2015-01-01

    To examine the association between vision loss and cardiorespiratory fitness among young and middle-age U.S. adults. The study had a cross-sectional design. The National Health and Nutrition Examination Survey 1999-2004 served as the study setting. Study subjects included 3135 adults ages 20 to 49 years. Cardiorespiratory fitness was assessed from cardiorespiratory extrapolation using heart rate response during submaximal treadmill testing, with inadequate cardiorespiratory fitness defined as below the 60th percentile for age and gender. Visual acuity was objectively assessed for each eye. Multivariable regression (linear and logistic) models were computed to examine the association between cardiorespiratory fitness and vision. Poorer cardiorespiratory fitness (β = -3.7 mL O2/kg per minute; 95% confidence interval: -5.3 to -2.2) was observed in subjects with visual impairment after adjusting for age, gender, race/ethnicity, and comorbid illness. Participants with vision impairment, as compared with those with normal sight, had 4.4-fold higher odds of having inadequate cardiorespiratory fitness (95% confidence interval: 1.04-18.97), whereas participants with uncorrected refractive error were not more likely to demonstrate poorer cardiorespiratory fitness. Adults with visual impairment, but not adults with uncorrected refractive error, demonstrate a significant reduction in cardiorespiratory fitness and are much more likely to have inadequate fitness compared with those with normal vision. Evaluation and implementation of strategies to increase cardiorespiratory fitness among those with vision impairment, in particular, are needed.

  8. Craniopharyngioma causing bilateral vision loss 4 months after unremarkable magnetic resonance imaging of the brain

    Directory of Open Access Journals (Sweden)

    Rainy Betts

    2015-01-01

    Full Text Available A 65-year-old man developed bilateral vision loss 4 months after magnetic resonance imaging demonstrated no lesion in the vicinity of the optic chiasm, hypothalamus, and suprasellar tissues. Repeat computed tomography 3 months later showed a predominantly cystic mass of the suprasellar cistern with extension into the anterior third ventricle, which histologically was a craniopharyngioma. The clinical course of this case fuels the controversy whether craniopharyngiomas arise from embryonic rests or can be acquired. From a clinical perspective, it raises questions about when to obtain imaging studies dedicated to the chiasm and the appropriate interval in which a scan should be repeated to exclude structural causes of bilateral vision loss.

  9. TrkB Activators for the Treatment of Traumatic Vision Loss

    Science.gov (United States)

    2016-10-01

    appropriate dry eye treatment . Such optimized treatment is of major interest as possible scarring of the filtration site is a known major threat for...Society for Eye Resear... http://www.abstractserver.com/iser2016/absmgm/printpreview.php? 1 of 1 5/26/16, 11:25 AM ORAL PRESEN TATIONS Ocular...for the treatment of t rauma-induced vision loss. Activation of the Innate Immune System Following Blast Injury to the Eye ELDON GEISERT, Felix

  10. [Acute monocular loss of vision : Differential diagnostic considerations apart from the internistic etiological clarification].

    Science.gov (United States)

    Rickmann, A; Macek, M A; Szurman, P; Boden, K

    2017-08-03

    We report the case of acute painless monocular loss of vision in a 53-year-old man. An interdisciplinary etiological evaluation remained without pathological findings with respect to arterial branch occlusion. A reevaluation of the patient history led to a possible association with the administration of phosphodiesterase type 5 inhibitor (PDE5 inhibitor). A critical review of the literature on PDE5 inhibitor administration with ocular participation was performed.

  11. Dietary Approaches to Protect Against Eye Blast Induced Oxidative Stress and Vision Loss

    Science.gov (United States)

    2016-11-01

    type (C57Bl/6) and Gulo-/- mice maintained on normal or low vitamin C. C, D ) MDA levels in the A) cortex and B) liver of Gulo-/- mice maintained...significantly to the progressive cell death and neuronal degeneration that we detect after ocular trauma and, thus, treating with Vitamins C and E or a...we may have identified IL-1 as an important mediator of vision loss after ocular trauma. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17

  12. Heuristics in primary care for recognition of unreported vision loss in older people: a technology development study.

    Science.gov (United States)

    Wijeyekoon, Skanda; Kharicha, Kalpa; Iliffe, Steve

    2015-09-01

    To evaluate heuristics (rules of thumb) for recognition of undetected vision loss in older patients in primary care. Vision loss is associated with ageing, and its prevalence is increasing. Visual impairment has a broad impact on health, functioning and well-being. Unrecognised vision loss remains common, and screening interventions have yet to reduce its prevalence. An alternative approach is to enhance practitioners' skills in recognising undetected vision loss, by having a more detailed picture of those who are likely not to act on vision changes, report symptoms or have eye tests. This paper describes a qualitative technology development study to evaluate heuristics for recognition of undetected vision loss in older patients in primary care. Using a previous modelling study, two heuristics in the form of mnemonics were developed to aid pattern recognition and allow general practitioners to identify potential cases of unreported vision loss. These heuristics were then analysed with experts. Findings It was concluded that their implementation in modern general practice was unsuitable and an alternative solution should be sort.

  13. Core losses of a permanent magnet synchronous motor with an amorphous stator core under inverter and sinusoidal excitations

    Science.gov (United States)

    Yao, Atsushi; Sugimoto, Takaya; Odawara, Shunya; Fujisaki, Keisuke

    2018-05-01

    We report core loss properties of permanent magnet synchronous motors (PMSM) with amorphous magnetic materials (AMM) core under inverter and sinusoidal excitations. To discuss the core loss properties of AMM core, a comparison with non-oriented (NO) core is also performed. In addition, based on both experiments and numerical simulations, we estimate higher (time and space) harmonic components of the core losses under inverter and sinusoidal excitations. The core losses of PMSM are reduced by about 59% using AMM stator core instead of NO core under sinusoidal excitation. We show that the average decrease obtained by using AMM instead of NO in the stator core is about 94% in time harmonic components.

  14. The influence of the inverter switching frequency on rotor losses in high-speed permanent magnet machines : an experimental study

    NARCIS (Netherlands)

    Merdzan, M.; Paulides, J. J H; Borisavljevic, A.; Lomonova, E. A.

    2016-01-01

    Harmonic content of the output voltage of pulse width modulated voltage source inverters (PWM VSI) is determined by the switching frequency. On the other hand, rotor losses in high-speed permanent magnet (PM) machines are caused, among other factors, by harmonics in stator currents. These harmonics

  15. Should We Provide Life-Sustaining Treatments to Patients with Permanent Loss of Cognitive Capacities?

    Directory of Open Access Journals (Sweden)

    Ofra G. Golan

    2012-07-01

    Full Text Available A very troubling issue for health care systems today is that of life-sustaining treatment for patients who have permanently lost their cognitive capacities. These include patients in persistent vegetative state (PVS, or minimally conscious state (MCS, as well as a growing population of patients at the very end stage of dementia. These patients are totally dependent on life-sustaining treatments and are, actually, kept alive “artificially.” This phenomenon raises doubts as to the ethics of sustaining the life of patients who have lost their consciousness and cognitive capacities, and whether there is a moral obligation to do so. The problem is that the main facts concerning the experiences and well-being of such patients and their wishes are unknown. Hence the framework of the four principles—beneficence, non-maleficence, autonomy, and justice—is not applicable in these cases; therefore we examined solidarity as another moral value to which we may resort in dealing with this dilemma. This article shows that the source of the dilemma is the social attitudes towards loss of cognitive capacities, and the perception of this state as loss of personhood. Consequently, it is suggested that the principle of solidarity—which both sets an obligation to care for the worst-off, and can be used to identify obligations that appeal to an ethos of behavior—can serve as a guiding principle for resolving the dilemma. The value of solidarity can lead society to care for these patients and not deny them basic care and life-sustaining treatment when appropriate.

  16. Emotional and behaviour difficulties in teenagers with permanent childhood hearing loss.

    Science.gov (United States)

    Stevenson, Jim; Pimperton, Hannah; Kreppner, Jana; Worsfold, Sarah; Terlektsi, Emmanouela; Kennedy, Colin

    2017-10-01

    It is known that during the middle childhood years those with permanent childhood hearing loss (PCHL) are at increased risk of showing emotional and behaviour difficulties (EBD). It has yet to be established whether this risk continues into the late teenage years. There is a paucity of longitudinal studies on the association between PCHL and EBD. The Strengths and Difficulties Questionnaire (SDQ) was used to measure EBD based on parent, teacher and self-ratings in 76 teenagers with PCHL and 38 in a hearing comparison group (HCG) from a population sample of children that was followed up from birth to adolescence. On parent-rated SDQ, the PCHL group had significantly higher Total Difficulties score than the HCG (Standardised mean difference (SMD) = +0.39, 95%CI 0.00 to 0.79). Amongst the PCHL group the presence of disabilities other than hearing loss had a substantial impact on the level of parent-rated EBD (SMD = +1.68, 1.04 to 2.33). There was a relationship between receptive language ability and EBD in both the HCG (r = -0.33, 95%CI -0.59 to -0.01) and the PCHI group (r = -0.33, 95%CI -0.53 to -0.02). The effect of PCHL on EBD became non-significant when receptive language was included as a covariate (F = 0.12, df = 1,95, p = 0.729). Early confirmation of hearing loss (i.e. before 9 months of age) did not have a significant effect on EBD scores (SMD = +0.31, 95%CI -0.15 to 0.77). PCHL continues to be associated with elevated EBD scores as measured by parent rated SDQ into the late teenage years but the degree of this elevation is less than in childhood and is not apparent on teacher or self-ratings. Poor receptive language ability appeared to account for these elevated EBD scores in the group with PCHL. Particular attention needs to be paid to the mental health of children and adolescents with PCHL that is accompanied by other disabilities and to those with poor receptive language ability. However, the majority of teenagers with PCHL do not

  17. NEURORETINITIS : A RARE CASE REPORT OF SUDDEN LOSS OF VISION IN YOUNG ADULT

    Directory of Open Access Journals (Sweden)

    Padmini

    2015-05-01

    Full Text Available Neuro retinitis (NR though a rare disease occurring in young adults , mostly unilateral is an inflammatory disorder characterized by swelling of optic nerve head and adjoining retinal nerve fibre layer resulting in a typical Macular star configuration due to lipid exudation within macula and fovea. Neuroretinitis can be due to an infectious process involving the disc , a post viral event , of an autoimmune inflammatory mechanism or sometimes idiopathic in nature resulting in a sudden loss of vision in affected eye along with multiple pupillary defects in form of Anisokoria ( dilated on affected side , Marcus Gunn pupil or ill sustained pupillary reactions . Patients may also present with painful ocular movements mostly adduction and elevation of the eye . Features common to above all 3 groups included age , absence of pain and fundus findings . Preceding systemic symptoms and visual field loss are more common in patient with Cat scratch disease and Multiple Sclerosis and uncommon in those with recurrences . With today’s technological advances , decision making regarding evaluation and treatment of NR is made accurately to reduce the incidence of optic atrophy which leads to total loss of vision

  18. Psychologic adjustment to irreversible vision loss in adults: a systematic review.

    Science.gov (United States)

    Senra, Hugo; Barbosa, Fernando; Ferreira, Patrícia; Vieira, Cristina R; Perrin, Paul B; Rogers, Heather; Rivera, Diego; Leal, Isabel

    2015-04-01

    To summarize relevant evidence investigating the psychologic adjustment to irreversible vision loss (IVL) in adults. Irreversible vision loss entails a challenging medical condition in which rehabilitation outcomes are strongly dependent on the patient's psychologic adjustment to illness and impairment. So far, no study has systematically reviewed the psychologic adjustment to IVL in adults. We reviewed all articles examining the psychologic adjustment to IVL in adults. We included articles published in English in peer-reviewed journals. We performed a keyword literature search using 4 databases (PubMed, EBSCO, Cochrane Library, and Science Direct) for all years through July 2014. We assessed risk of bias of selected studies using the RTI Item Bank for Assessing Risk of Bias and Confounding for Observational Studies of Interventions or Exposures and the Cochrane risk of bias tool for randomized controlled trials. Of a total of 3948 citations retrieved, we selected 52 eligible studies published between 1946 and 2014. The majority of studies were observational and cross-sectional in nature. Our review suggests that high levels of depression occur during the adjustment to IVL. Better adjustment to IVL was associated with greater acceptance of vision loss and use of instrumental coping, good social support, positivity, and use of assistive aids. The overall findings indicate that IVL often has negative effects on patients' quality of life and mental health and that such effects tend to remain over time. Specific factors and variables associated with the adjustment to IVL need to be clarified through further in-depth and longitudinal research. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  19. Sudden Unilateral Vision Loss Arising from Calcified Amorphous Tumor of the Left Ventricle

    Science.gov (United States)

    Nazli, Yunus; Colak, Necmettin; Atar, Inci Asli; Alpay, Mehmet Fatih; Haltas, Hacer; Eryonucu, Beyhan; Cakir, Omer

    2013-01-01

    Calcified amorphous tumor of the heart is a very rare non-neoplastic intracavitary mass. The clinical presentation is similar to that of other cardiac masses. The precise cause and best approach to treatment remain unclear. We describe a case of cardiac calcified amorphous tumor presenting with refractory unilateral vision loss that was successfully treated by surgical excision. To our knowledge, this is only the 2nd reported case of retinal arterial embolism due to cardiac calcified amorphous tumor in the English-language literature. PMID:24082378

  20. Spatial updating depends on gaze direction even after loss of vision.

    Science.gov (United States)

    Reuschel, Johanna; Rösler, Frank; Henriques, Denise Y P; Fiehler, Katja

    2012-02-15

    Direction of gaze (eye angle + head angle) has been shown to be important for representing space for action, implying a crucial role of vision for spatial updating. However, blind people have no access to vision yet are able to perform goal-directed actions successfully. Here, we investigated the role of visual experience for localizing and updating targets as a function of intervening gaze shifts in humans. People who differed in visual experience (late blind, congenitally blind, or sighted) were briefly presented with a proprioceptive reach target while facing it. Before they reached to the target's remembered location, they turned their head toward an eccentric direction that also induced corresponding eye movements in sighted and late blind individuals. We found that reaching errors varied systematically as a function of shift in gaze direction only in participants with early visual experience (sighted and late blind). In the late blind, this effect was solely present in people with moveable eyes but not in people with at least one glass eye. Our results suggest that the effect of gaze shifts on spatial updating develops on the basis of visual experience early in life and remains even after loss of vision as long as feedback from the eyes and head is available.

  1. Improved reading performance using individualized compensation filters for observers with losses in central vision

    Science.gov (United States)

    Lawton, Teri B.

    1989-01-01

    A method to improve the reading performance of subjects with losses in central vision is proposed in which the amplitudes of the intermediate spatial frequencies are boosted relative to the lower spatial frequencies. In the method, words are filtered using an image enhancement function which is based on a subject's losses in visual function relative to a normal subject. It was found that 30-70 percent less magnification was necessary, and that reading rates were improved 2-3 times, using the method. The individualized compensation filters improved the clarity and visibility of words. The shape of the enhancement function was shown to be important in determining the optimum compensation filter for improving reading performance.

  2. Visual system plasticity in mammals: the story of monocular enucleation-induced vision loss

    Science.gov (United States)

    Nys, Julie; Scheyltjens, Isabelle; Arckens, Lutgarde

    2015-01-01

    The groundbreaking work of Hubel and Wiesel in the 1960’s on ocular dominance plasticity instigated many studies of the visual system of mammals, enriching our understanding of how the development of its structure and function depends on high quality visual input through both eyes. These studies have mainly employed lid suturing, dark rearing and eye patching applied to different species to reduce or impair visual input, and have created extensive knowledge on binocular vision. However, not all aspects and types of plasticity in the visual cortex have been covered in full detail. In that regard, a more drastic deprivation method like enucleation, leading to complete vision loss appears useful as it has more widespread effects on the afferent visual pathway and even on non-visual brain regions. One-eyed vision due to monocular enucleation (ME) profoundly affects the contralateral retinorecipient subcortical and cortical structures thereby creating a powerful means to investigate cortical plasticity phenomena in which binocular competition has no vote.In this review, we will present current knowledge about the specific application of ME as an experimental tool to study visual and cross-modal brain plasticity and compare early postnatal stages up into adulthood. The structural and physiological consequences of this type of extensive sensory loss as documented and studied in several animal species and human patients will be discussed. We will summarize how ME studies have been instrumental to our current understanding of the differentiation of sensory systems and how the structure and function of cortical circuits in mammals are shaped in response to such an extensive alteration in experience. In conclusion, we will highlight future perspectives and the clinical relevance of adding ME to the list of more longstanding deprivation models in visual system research. PMID:25972788

  3. Diagnosis System for Diabetic Retinopathy and Glaucoma Screening to Prevent Vision Loss

    Directory of Open Access Journals (Sweden)

    Siva Sundhara Raja DHANUSHKODI

    2014-03-01

    Full Text Available Aim: Diabetic retinopathy (DR and glaucoma are two most common retinal disorders that are major causes of blindness in diabetic patients. DR caused in retinal images due to the damage in retinal blood vessels, which leads to the formation of hemorrhages spread over the entire region of retina. Glaucoma is caused due to hypertension in diabetic patients. Both DR and glaucoma affects the vision loss in diabetic patients. Hence, a computer aided development of diagnosis system for Diabetic retinopathy and Glaucoma screening is proposed in this paper to prevent vision loss. Method: The diagnosis system of DR consists of two stages namely detection and segmentation of fovea and hemorrhages. The diagnosis system of glaucoma screening consists of three stages namely blood vessel segmentation, Extraction of optic disc (OD and optic cup (OC region and determination of rim area between OD and OC. Results: The specificity and accuracy for hemorrhages detection is found to be 98.47% and 98.09% respectively. The accuracy for OD detection is found to be 99.3%. This outperforms state-of-the-art methods. Conclusion: In this paper, the diagnosis system is developed to classify the DR and glaucoma screening in to mild, moderate and severe respectively.

  4. Mental stress as consequence and cause of vision loss: the dawn of psychosomatic ophthalmology for preventive and personalized medicine.

    Science.gov (United States)

    Sabel, Bernhard A; Wang, Jiaqi; Cárdenas-Morales, Lizbeth; Faiq, Muneeb; Heim, Christine

    2018-06-01

    The loss of vision after damage to the retina, optic nerve, or brain has often grave consequences in everyday life such as problems with recognizing faces, reading, or mobility. Because vision loss is considered to be irreversible and often progressive, patients experience continuous mental stress due to worries, anxiety, or fear with secondary consequences such as depression and social isolation. While prolonged mental stress is clearly a consequence of vision loss, it may also aggravate the situation. In fact, continuous stress and elevated cortisol levels negatively impact the eye and brain due to autonomous nervous system (sympathetic) imbalance and vascular dysregulation; hence stress may also be one of the major causes of visual system diseases such as glaucoma and optic neuropathy. Although stress is a known risk factor, its causal role in the development or progression of certain visual system disorders is not widely appreciated. This review of the literature discusses the relationship of stress and ophthalmological diseases. We conclude that stress is both consequence and cause of vision loss. This creates a vicious cycle of a downward spiral, in which initial vision loss creates stress which further accelerates vision loss, creating even more stress and so forth. This new psychosomatic perspective has several implications for clinical practice. Firstly, stress reduction and relaxation techniques (e.g., meditation, autogenic training, stress management training, and psychotherapy to learn to cope) should be recommended not only as complementary to traditional treatments of vision loss but possibly as preventive means to reduce progression of vision loss. Secondly, doctors should try their best to inculcate positivity and optimism in their patients while giving them the information the patients are entitled to, especially regarding the important value of stress reduction. In this way, the vicious cycle could be interrupted. More clinical studies are now

  5. Core losses of a permanent magnet synchronous motor with an amorphous stator core under inverter and sinusoidal excitations

    Directory of Open Access Journals (Sweden)

    Atsushi Yao

    2018-05-01

    Full Text Available We report core loss properties of permanent magnet synchronous motors (PMSM with amorphous magnetic materials (AMM core under inverter and sinusoidal excitations. To discuss the core loss properties of AMM core, a comparison with non-oriented (NO core is also performed. In addition, based on both experiments and numerical simulations, we estimate higher (time and space harmonic components of the core losses under inverter and sinusoidal excitations. The core losses of PMSM are reduced by about 59% using AMM stator core instead of NO core under sinusoidal excitation. We show that the average decrease obtained by using AMM instead of NO in the stator core is about 94% in time harmonic components.

  6. Improved Eddy-current Field Loss Model and Scaling Index for Magnets of Permanent Magnet Synchronous Motors

    Directory of Open Access Journals (Sweden)

    Zhang Lei

    2015-01-01

    Full Text Available The paper gives detailed systematic researches on the mechanism and key factors of eddy-current losses in rotor magnets of high power-density permanent magnet synchronous motors(PMSMs. Firstly, this paper establishes quantitative mathematic model of eddy-current losses for surface-mounted PMSM based on eddy current field model and Maxwell equations. Then, a scaling index is put forward to weigh the key factors relevant to the eddy-current losses in magnets. At the same time, the principles of eddy-current losses in prototype PMSM are analyzed by the finite element analysis (FEA software. The contents researched in the paper have practical reference values for design and reliability analysis of PMSMs.

  7. Adjustment to acquired vision loss in adults presenting for visual disability certification

    Directory of Open Access Journals (Sweden)

    Aditya Nakade

    2017-01-01

    Full Text Available Context: Rehabilitation of the visually disabled depends on how they adjust to loss; understanding contributing factors may help in effective rehabilitation. Aim: The aim of this study is to assess adjustment to acquired vision loss in adults. Settings and Design: This observational study, conducted in the Department of Ophthalmology at a tertiary-level teaching hospital, included thirty persons (25–65 years with <6/60 in the better eye, and vision loss since ≥6-months. Materials and Methods: Age, gender, rural/urban residence, education, current occupation, binocular distance vision, adjustment (Acceptance and Self-Worth Adjustment Scale, depression (Center for Epidemiologic Studies-Depression Scale, social support (Duke Social Support and Stress Scale, and personality (10-item Personality Inventory scale was recorded. Statistical Analysis: To determine their effect on adjustment, Student's t-test was used for categorical variables, Pearson's correlation for age, and Spearman's correlation for depression, personality trait and social support and stress. Results: Of 30 persons recruited, 24 were men (80%; 24 lived in urban areas (80%; 9 were employed (30%; and 14 (46.6% had studied < Class 3. Adjustment was low (range: 33%–60%; mean: 43.6 ± 5.73. Reported support was low (median: 27.2; interquartile range [IQR]: 18.1–36.3; reported stress was low (median: 0.09; IQR: 0–18.1. Predominant personality traits (max score 14 were “Agreeableness” (average 12.0 ± 1.68 and “Conscientiousness” (average 11.3 ± 2.12. Emotional stability (average 9.2 ± 2.53 was less prominent. Depression score ranged from 17 to 50 (average 31.6 ± 6.01. The factors studied did not influence adjustment. Conclusions: Although adjustment did not vary with factors studied, all patients were depressed. Since perceived support and emotional stability was low, attention could be directed to support networks. Training patients in handling emotions, and training

  8. WHO Environmental Noise Guidelines for the European Region: A Systematic Review on Environmental Noise and Permanent Hearing Loss and Tinnitus.

    Science.gov (United States)

    Śliwińska-Kowalska, Mariola; Zaborowski, Kamil

    2017-09-27

    Background : Hearing loss is defined as worsening of hearing acuity and is usually expressed as an increase in the hearing threshold. Tinnitus, defined as "ringing in the ear", is a common and often disturbing accompaniment of hearing loss. Hearing loss and environmental exposures to noise are increasingly recognized health problems. Objectives : The objective was to assess whether the exposure-response relationship can be established between exposures to non-occupational noise and permanent hearing outcomes such as permanent hearing loss and tinnitus. Methods: Information sources : Computer searches of all accessible medical and other databases (PubMed, Web of Science, Scopus) were performed and complemented with manual searches. The search was not limited to a particular time span, except for the effects of personal listening devices (PLDs). The latter was limited to the years 2008-June 2015, since previous knowledge was summarized by SCENIHR descriptive systematic review published in 2008. Study eligibility criteria: The inclusion criteria were as follows: the exposure to noise was measured in sound pressure levels (SPLs) and expressed in individual equivalent decibel values (L EX,8h ), the studies included both exposed and reference groups, the outcome was a permanent health effect, i.e., permanent hearing loss assessed with pure-tone audiometry and/or permanent tinnitus assessed with a questionnaire. The eligibility criteria were evaluated by two independent reviewers. Study appraisal and synthesis methods: The risk of bias was assessed for all of the papers using a template for assessment of quality and the risk of bias. The GRADE (grading of recommendations assessment, development, and evaluation) approach was used to assess the overall quality of evidence. Meta-analysis was not possible due to methodological heterogeneity of included studies and the inadequacy of data. Results: Out of 220 references identified, five studies fulfilled the inclusion criteria

  9. Rescue of cell death and inflammation of a mouse model of complex 1-mediated vision loss by repurposed drug molecules.

    Science.gov (United States)

    Yu, Alfred K; Datta, Sandipan; McMackin, Marissa Z; Cortopassi, Gino A

    2017-12-15

    Inherited mitochondrial optic neuropathies, such as Leber's hereditary optic neuropathy (LHON) and Autosomal dominant optic atrophy (ADOA) are caused by mutant mitochondrial proteins that lead to defects in mitochondrial complex 1-driven ATP synthesis, and cause specific retinal ganglion cell (RGC) loss. Complex 1 defects also occur in patients with primary open angle glaucoma (POAG), in which there is specific RGC loss. The treatment of mitochondrial optic neuropathy in the US is only supportive. The Ndufs4 knockout (Ndufs4 KO) mouse is a mitochondrial complex 1-deficient model that leads to RGC loss and rapid vision loss and allows for streamlined testing of potential therapeutics. Preceding RGC loss in the Ndufs4 KO is the loss of starburst amacrine cells, which may be an important target in the mechanism of complex 1-deficient vision loss. Papaverine and zolpidem were recently shown to be protective of bioenergetic loss in cell models of optic neuropathy. Treatment of Ndufs4 KO mice with papaverine, zolpidem, and rapamycin-suppressed inflammation, prevented cell death, and protected from vision loss. Thus, in the Ndufs4 KO mouse model of mitochondrial optic neuropathy, papaverine and zolpidem provided significant protection from multiple pathophysiological features, and as approved drugs in wide human use could be considered for the novel indication of human optic neuropathy. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Gender inequality in vision loss and eye diseases: Evidence from the Sultanate of Oman

    Directory of Open Access Journals (Sweden)

    Khandekar Rajiv

    2009-01-01

    Full Text Available Purpose : The data from surveys of vision loss and monitoring of services were used to assess changes in gender inequality in Oman. Study Design : Retrospective review of data collection instruments. Materials and Method : The data sets of 12 years between 1996 and 2007 were abstracted to assess the gender equality for vision loss, eye disease prevalence, and service use. They included two surveys (1996 and 2005, Health Information from eye units (1998 and 2007, and eye screening in schools. Results : In 1996, the prevalence of bilateral blindness in ≥ 40 years of age was higher in females [Odd′s Ratio (OR = 0.36 (95% Confidence Interval (CI 0.24 - 0.53]. Gender differences in the prevalence of cataract [OR = 0.82 (95% CI 0.63 - 1.03] were not significant while trachomatous trichaisis (TT was less in males [OR = 0.33 (95% CI 0.22-0.48]. In 2005, gender differences in the prevalence of bilateral blindness [OR = 0.97 (95% CI 0.71 - 1.34] and TT [OR = 0.66 (95% CI 0.42- 1.04] were not statistically significant.But males were associated with higher prevalence of cataract [OR = 1.26 (95% CI 1.00 - 1.59]. Surgery rates for cataract, glaucoma and TT were not different by gender. More male compared to female patients with diabetic retinopathy were treated. Myopia was significantly higher in girls. Compliance of spectacle wear was higher in girls. Conclusions : Gender inequality for eye care seems to have reduced in the last 10 years in Oman. However, apart from TT and glaucoma patients the difference in service utilization by gender was not statistically significant.

  11. Electromagnetic Design and Losses Analysis of a High-Speed Permanent Magnet Synchronous Motor with Toroidal Windings for Pulsed Alternator

    Directory of Open Access Journals (Sweden)

    Yuan Wan

    2018-03-01

    Full Text Available The configuration of conventional high-speed Permanent Magnet Synchronous Motors (PMSMs is usually long and thin, with overlong axial end winding lengths, which is not suitable for those applications that place severe restrictions on the axial length, such as pulsed alternators. This paper first studied the key design aspects of a flat-structure high-speed PMSM. The toroidal-windings, low-conductivity material of the retaining sleeve, large airgap and segmentation of magnets were studied to reduce the axial length of the motor. The division of the stator and the employment of a non-magnetic outer stator were used to improve overall performance. Then the losses of the prototype were calculated and the factors having an influence on the losses were also investigated, after which, their effects on the total loss were evaluated. The total loss could be effectively reduced by the decrease of strand number of conductors and the division of stator, while only being slightly reduced by epoxy resin pole fillers. Metal-stack pole fillers have the same effect on the reduction of rotor loss as epoxy resin, while maintaining the good thermal-conductivity of metal. In addition, the influence of the carrier frequency of the inverter on the losses was analyzed, and it was found that high carrier frequency was helpful to reduce rotor losses. Finally, a small-scale prototype was manufactured and the experimental results were provided.

  12. Core losses of an inverter-fed permanent magnet synchronous motor with an amorphous stator core under no-load

    Directory of Open Access Journals (Sweden)

    Nicolas Denis

    2016-05-01

    Full Text Available In this paper, an interior permanent magnet synchronous motor (IPMSM with a stator core made of amorphous magnetic material (AMM is presented. The IPMSM is driven by a voltage source three-phase inverter with classical pulse width modulation (PWM control. The core losses under no-load condition are measured by experiment and compared to an equivalent IPMSM with a stator core made of NO steel. Under these conditions, the core losses are influenced by the stator, rotor and magnet shapes but also by the PWM carrier signal that implies a high frequency harmonic in the magnetic flux density. It is demonstrated that the AMM can reduce the core losses by about 56 %.

  13. Loss of permanent employment and its association with suicidal ideation: a cohort study in South Korea.

    Science.gov (United States)

    Yoon, Seohyun; Kim, Ja Young; Park, Jooyoung; Kim, Seung-Sup

    2017-09-01

    Objective Precarious employment is associated with worse mental health, but it is unclear whether changes in employment status are related to suicidal behaviors. This study examined the association between change in employment status and suicidal ideation among workers in South Korea. Methods To maximize power of the analysis, we combined data from the ongoing Korean Welfare Panel Study. We analyzed 3793 participants who were permanent workers at baseline (2011-2014) and who either: (i) maintained permanent employment; (ii) became a full-time precarious worker; (iii) became a part-time precarious worker; or (iv) became unemployed in the following year (2012-2015). Suicidal ideation was assessed annually by asking participants, "Have you ever seriously thought about dying by suicide in the past year?" Logistic regression was applied to examine associations between change in employment status and suicidal ideation, adjusting for potential confounders such as lifetime suicidal ideation and depressive symptoms at baseline. Results Participants who became part-time precarious workers were more likely to have suicidal ideation [odd ratio (OR) 2.37, 95% confidence interval (95% CI) 1.07-5.25, P=0.033] compared to those who remained permanent workers. In analysis restricted to workers who never previously thought about dying by suicide, suicidal ideation was more common among those who became either full-time (OR 2.33, 95% CI 1.09-4.99, P=0.029) or part-time (OR 3.94, 95% CI 1.46-10.64, P=0.007) precarious workers. Conclusions Our findings suggest that change in employment status from permanent to precarious employment may increase suicidal ideation among workers in South Korea.

  14. A Grass-Roots Endeavor To Develop a Permanent University Program for Vision Professionals: The North Carolina Model.

    Science.gov (United States)

    Walker, Brad R.; Bozeman, Laura A.

    2002-01-01

    This article describes a collaborative process that parents, teachers, consumers, and advocacy groups in North Carolina used to successfully establish a permanently funded university training program specializing in visual impairments, the Visual Impairment Training Program. Within this process several factors were identified that contributed to…

  15. Evaluation of family history of permanent hearing loss in childhood as a risk indicator in universal screening.

    Science.gov (United States)

    Valido Quintana, Mercedes; Oviedo Santos, Ángeles; Borkoski Barreiro, Silvia; Santana Rodríguez, Alfredo; Ramos Macías, Ángel

    Sixty percent of prelingual hearing loss is of genetic origin. A family history of permanent childhood hearing loss is a risk factor. The objective of the study is to determine the relationship between this risk factor and hearing loss. We have evaluated clinical and epidemiological characteristics and related nonsyndromic genetic variation. This was a retrospective, descriptive and observational study of newborns between January 2007 and December 2010 with family history as risk factor for hearing loss using transient evoked otoacoustic emissions and auditory brainstem response. A total of 26,717 children were born. Eight hundred and fifty-seven (3.2%) had family history. Fifty-seven(0.21%) failed to pass the second test. A percentage of 29.1 (n=16) had another risk factor, and 17.8% (n=9) had no classical risk factor. No risk factor was related to the hearing loss except heart disease. Seventy-six point four percent had normal hearing and 23.6% hearing loss. The mean of family members with hearing loss was 1.25. On genetic testing, 82.86% of homozygotes was normal, 11.43% heterozygosity in Connexin 26 gene (35delG), 2.86% R143W heterozygosity in the same gene and 2.86% mutant homozygotes (35delG). We found no relationship between hearing loss and mutated allele. The percentage of children with a family history and hearing loss is higher than expected in the general population. The genetic profile requires updating to clarify the relationship between hearing loss and heart disease, family history and the low prevalence in the mutations analyzed. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

  16. The effect of surface grain reversal on the AC losses of sintered Nd–Fe–B permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Martina, E-mail: m.moore@ifw-dresden.de [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, 01171 Dresden (Germany); Roth, Stefan; Gebert, Annett [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, 01171 Dresden (Germany); Schultz, Ludwig [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, 01171 Dresden (Germany); TU Dresden, Institute for Materials Science, 01062 Dresden (Germany); Gutfleisch, Oliver [TU Darmstadt, Department of Materials Science, Alarich-Weiß-Str. 16, 64287 Darmstadt (Germany); Fraunhofer Project Group for Materials Recycling and Resource Strategies IWKS, 63457 Hanau (Germany)

    2015-02-01

    Sintered Nd–Fe–B magnets are exposed to AC magnetic fields in many applications, e.g. in permanent magnet electric motors. We have measured the AC losses of sintered Nd–Fe–B magnets in a closed circuit arrangement using AC fields with root mean square-values up to 80 mT (peak amplitude 113 mT) over the frequency range 50 to 1000 Hz. Two magnet grades with different dysprosium content were investigated. Around the remanence point the low grade material (1.7 wt% Dy) showed significant hysteresis losses; whereas the losses in the high grade material (8.9 wt% Dy) were dominated by classical eddy currents. Kerr microscopy images revealed that the hysteresis losses measured for the low grade magnet can be mainly ascribed to grains at the sample surface with multiple domains. This was further confirmed when the high grade material was subsequently exposed to DC and AC magnetic fields. Here a larger number of surface grains with multiple domains are also present once the step in the demagnetization curve attributed to the surface grain reversal is reached and a rise in the measured hysteresis losses is evident. If in the low grade material the operating point is slightly offset from the remanence point, such that zero field is not bypassed, its AC losses can also be fairly well described with classical eddy current theory. - Highlights: • The eddy current losses of sintered Nd–Fe–B magnets were measured. • Field amplitudes up to 113 mT over the frequency range 50 to 1000 Hz were applied. • The Nd–Fe–B magnets showed significant hysteresis losses at low amplitudes (∼100 mT). • The source of such hysteresis losses in sintered Nd–Fe–B magnets was identified. • Two magnet grades with different dysprosium content were investigated.

  17. The effect of surface grain reversal on the AC losses of sintered Nd–Fe–B permanent magnets

    International Nuclear Information System (INIS)

    Moore, Martina; Roth, Stefan; Gebert, Annett; Schultz, Ludwig; Gutfleisch, Oliver

    2015-01-01

    Sintered Nd–Fe–B magnets are exposed to AC magnetic fields in many applications, e.g. in permanent magnet electric motors. We have measured the AC losses of sintered Nd–Fe–B magnets in a closed circuit arrangement using AC fields with root mean square-values up to 80 mT (peak amplitude 113 mT) over the frequency range 50 to 1000 Hz. Two magnet grades with different dysprosium content were investigated. Around the remanence point the low grade material (1.7 wt% Dy) showed significant hysteresis losses; whereas the losses in the high grade material (8.9 wt% Dy) were dominated by classical eddy currents. Kerr microscopy images revealed that the hysteresis losses measured for the low grade magnet can be mainly ascribed to grains at the sample surface with multiple domains. This was further confirmed when the high grade material was subsequently exposed to DC and AC magnetic fields. Here a larger number of surface grains with multiple domains are also present once the step in the demagnetization curve attributed to the surface grain reversal is reached and a rise in the measured hysteresis losses is evident. If in the low grade material the operating point is slightly offset from the remanence point, such that zero field is not bypassed, its AC losses can also be fairly well described with classical eddy current theory. - Highlights: • The eddy current losses of sintered Nd–Fe–B magnets were measured. • Field amplitudes up to 113 mT over the frequency range 50 to 1000 Hz were applied. • The Nd–Fe–B magnets showed significant hysteresis losses at low amplitudes (∼100 mT). • The source of such hysteresis losses in sintered Nd–Fe–B magnets was identified. • Two magnet grades with different dysprosium content were investigated

  18. Incorporation of Finite Element Analysis into Annual Energy Loss Estimation for Permanent Magnet Wind Turbine Generators

    DEFF Research Database (Denmark)

    Henriksen, Matthew Lee; Jensen, Bogi Bech

    2013-01-01

    Several methods of estimating the annual energy losses for wind turbine generators are investigated in this paper. Utilizing a high amount of transient simulations with motion is first demonstrated. Usage of a space-time transformation for prediction of iron losses is also explored. The methods, ...

  19. Spatial contrast sensitivity vision loss in children with cortical visual impairment.

    Science.gov (United States)

    Good, William V; Hou, Chuan; Norcia, Anthony M

    2012-11-19

    Although cortical visual impairment (CVI) is the leading cause of bilateral vision impairment in children in Western countries, little is known about the effects of CVI on visual function. The aim of this study was to compare visual evoked potential measures of contrast sensitivity and grating acuity in children with CVI with those of age-matched typically developing controls. The swept parameter visual evoked potential (sVEP) was used to measure contrast sensitivity and grating acuity in 34 children with CVI at 5 months to 5 years of age and in 16 age-matched control children. Contrast thresholds and spatial frequency thresholds (grating acuities) were derived by extrapolating the tuning functions to zero amplitude. These thresholds and maximal suprathreshold response amplitudes were compared between groups. Among 34 children with CVI, 30 had measurable but reduced contrast sensitivity with a median threshold of 10.8% (range 5.0%-30.0% Michelson), and 32 had measurable but reduced grating acuity with median threshold 0.49 logMAR (9.8 c/deg, range 5-14 c/deg). These thresholds were significantly reduced, compared with age-matched control children. In addition, response amplitudes over the entire sweep range for both measures were significantly diminished in children with CVI compared with those of control children. Our results indicate that spatial contrast sensitivity and response amplitudes are strongly affected by CVI. The substantial degree of loss in contrast sensitivity suggests that contrast is a sensitive measure for evaluating vision deficits in patients with CVI.

  20. SECOND MOLAR UPRIGHTING AFTER PREMATURE LOSS OF MANDIBULAR FIRST PERMANENT MOLAR--CASE REPORT.

    Science.gov (United States)

    Cernei, E R; Mavru, R B; Zetui, Irina Nicoleta

    2015-01-01

    Uprighting a tipped molar by using an uprighting spring is a fundamental orthodontic treatment technique. Following a weak anchorage done only by the anterior teeth the permanent lower second molar will rotate around its center of resistance, and besides the distalizing movement will occur its extrusion. Following the reaction, the mandibular anterior teeth will have a movement of intrusion. All these elements will lead to anterior open bite. Correction of vertical problems has become easier with the advent of mini-implants. U.I patient aged 24 years presenting for aesthetic and functional disorders. Clinical examination reveals intraoral Class I molar malocclusion on the right sight, upper narrowing arch with a slight overbite, and the both permanent first molars on the left side lost prematurely. The tooth 37 is inclined at 600 degrees to the plane of occlusion. To avoid front opening occlusion we used an orthodontic miniscrew inserted between the canine and the first premolar on the same side to achieve the second molar up righting. Lower second molar uprighting was achieved without unwanted movements in anterior mandibular region and without molar extrusion. Using mini implants in uprighting a tipped molar will achieve the desired tooth movement and will reduce the number of unwanted side effects and eventually to improve patient's esthetics.

  1. Effect of shrink fitting and cutting on iron loss of permanent magnet motor

    International Nuclear Information System (INIS)

    Takahashi, N.; Morimoto, H.; Yunoki, Y.; Miyagi, D.

    2008-01-01

    Magnetic properties of a motor core are affected by the distortion due to the compression caused by shrink fitting and the distortion caused by punching, etc. In this paper, the B-H curve and iron loss of stator core of actual motor under shrink fitting are measured. It is shown that the maximum permeability is reduced by about 50%, and the iron loss is increased by about 30% due to the shrink fitting. It is illustrated that the loss of motor is increased by about 10%, 4% and 2% due to the shrink fitting, the cutting stress and the eddy current in rotor magnet, respectively

  2. Development of Interior Permanent Magnet Motors with Concentrated Windings for Reducing Magnet Eddy Current Loss

    Science.gov (United States)

    Yamazaki, Katsumi; Kanou, Yuji; Fukushima, Yu; Ohki, Shunji; Nezu, Akira; Ikemi, Takeshi; Mizokami, Ryoichi

    In this paper, we present the development of interior magnet motors with concentrated windings, which reduce the eddy current loss of the magnets. First, the mechanism of the magnet eddy current loss generation is investigated by a simple linear magnetic circuit. Due to the consideration, an automatic optimization method using an adaptive finite element method is carried out to determine the stator and rotor shapes, which decrease the eddy current loss of the magnet. The determined stator and rotor are manufactured in order to proof the effectiveness by the measurement.

  3. Eddy current loss analysis of open-slot fault-tolerant permanent-magnet machines based on conformal mapping method

    Science.gov (United States)

    Ji, Jinghua; Luo, Jianhua; Lei, Qian; Bian, Fangfang

    2017-05-01

    This paper proposed an analytical method, based on conformal mapping (CM) method, for the accurate evaluation of magnetic field and eddy current (EC) loss in fault-tolerant permanent-magnet (FTPM) machines. The aim of modulation function, applied in CM method, is to change the open-slot structure into fully closed-slot structure, whose air-gap flux density is easy to calculate analytically. Therefore, with the help of Matlab Schwarz-Christoffel (SC) Toolbox, both the magnetic flux density and EC density of FTPM machine are obtained accurately. Finally, time-stepped transient finite-element method (FEM) is used to verify the theoretical analysis, showing that the proposed method is able to predict the magnetic flux density and EC loss precisely.

  4. Filter Influence on Rotor Losses in Coreless Axial Flux Permanent Magnet Machines

    Directory of Open Access Journals (Sweden)

    SANTIAGO, J.

    2013-02-01

    Full Text Available This paper investigates the eddy current losses induced in the rotor of coreless Axial-Flux machines. The calculation of eddy currents in the magnets requires the simulation of the inverter and the filter to obtain the harmonic content of the stator currents and FEM analysis of the magnets in the rotor. Due to the low inductance in coreless machines, the induced eddy current losses in the rotor remain lower than in traditional slotted machines. If only machine losses are considered, filters in DC/AC converters are not required in machines with wide airgaps as time harmonic losses in the rotor are very low.The harmonic content both from simulations and experimental results of a DC/AC converter are used to calculate the eddy currents in the rotor magnets. The properties of coreless machine topologies are investigated and some simplifications are proposed for time efficient 3D-FEM analysis. The time varying magnetic field can be considered constant over the magnets when the pole is divided in several magnets.The simplified FEM method to calculate eddy current losses is applicable to coreless machines with poles split into several magnets, although the conclusions are applicable to all coreless and slotless motors and generators.

  5. Iron Loss Prediction Using Modified IEM-Formula during the Field Weakening for Permanent Magnet Synchronous Machines

    Directory of Open Access Journals (Sweden)

    Pedram Asef

    2017-12-01

    Full Text Available During field weakening operation time (FWOT, the total iron loss rises and affects the accuracy of loss prediction and efficiency, especially if a large range of FWOT exists due to a large voltage drop that was rooted from the resistance of the used material. Iron loss prediction is widely employed in investigations for a fast electrical machine analysis using 2D finite element analysis (FEA. This paper proposes harmonic loss analytically by a steady-state equivalent circuit with a novel procedure. Consideration of skin effects and iron saturation are utilized in order to examine the accuracy through the relative error distribution in the frequency domain of each model from 50 to 700 Hz. Additionally, this comparative study presents a torque-frequency-field density calculation over each single term of the modified institute of electrical machines formula (IEM-Formula. The proposed analytical calculation is performed using 2D FEA for a classic and modified IEM-Formula along with experimental verifications on a surface-mounted permanent magnet synchronous generator (PMSG for a wind generation application.

  6. Functional changes at the preferred retinal locus in subjects with bilateral central vision loss.

    Science.gov (United States)

    Krishnan, Arun Kumar; Bedell, Harold E

    2018-01-01

    Subjects with bilateral central vision loss (CVL) use a retinal region called the preferred retinal locus (PRL) for performing various visual tasks. We probed the fixation PRL in individuals with bilateral macular disease, including age-related macular degeneration (AMD) and Stargardt disease (STGD), for localized sensitivity deficits. Three letter words at the critical print size were presented in the NIDEK MP-1 microperimeter to determine the fixation PRL and its radial retinal eccentricity from the residual fovea in 29 subjects with bilateral CVL. Fixation stability was defined as the median bivariate contour ellipse area (BCEA) from 3 fixation assessments. A standard 10-2 grid (68 locations, 2° apart) was used to determine central retinal sensitivity for Goldmann size II test spots. Baseline and follow-up supra-threshold screening of the fixation PRL for localized sensitivity deficits was performed using high density (0.2° or 0.3° apart) 0 dB Goldmann size II test spots. Custom MATLAB code and a dual bootstrapping algorithm were used to register test-spot locations from the baseline and follow-up tests. Locations where the 0 dB test spots were not seen on either test were labeled as micro-scotomas (MSs). Median BCEA correlated poorly with the radial eccentricity of the fixation PRL. Mean (±SD) sensitivity around the PRL from 10-2 testing was 4.93 ± 4.73 dB. The average percentage of MSs was similar for patients with AMD (25.4%), STGD (20.3%), and other etiologies of CVL (27.1%). The fixation PRL in subjects with bilateral CVL frequently includes local regions of sensitivity loss.

  7. Development of a case-mix funding system for adults with combined vision and hearing loss.

    Science.gov (United States)

    Guthrie, Dawn M; Poss, Jeffrey W

    2013-04-15

    Adults with vision and hearing loss, or dual sensory loss (DSL), present with a wide range of needs and abilities. This creates many challenges when attempting to set the most appropriate and equitable funding levels. Case-mix (CM) funding models represent one method for understanding client characteristics that correlate with resource intensity. A CM model was developed based on a derivation sample (n = 182) and tested with a replication sample (n = 135) of adults aged 18+ with known DSL who were living in the community. All items within the CM model came from a standardized, multidimensional assessment, the interRAI Community Health Assessment and the Deafblind Supplement. The main outcome was a summary of formal and informal service costs which included intervenor and interpreter support, in-home nursing, personal support and rehabilitation services. Informal costs were estimated based on a wage rate of half that for a professional service provider ($10/hour). Decision-tree analysis was used to create groups with homogeneous resource utilization. The resulting CM model had 9 terminal nodes. The CM index (CMI) showed a 35-fold range for total costs. In both the derivation and replication sample, 4 groups (out of a total of 18 or 22.2%) had a coefficient of variation value that exceeded the overall level of variation. Explained variance in the derivation sample was 67.7% for total costs versus 28.2% in the replication sample. A strong correlation was observed between the CMI values in the two samples (r = 0.82; p = 0.006). The derived CM funding model for adults with DSL differentiates resource intensity across 9 main groups and in both datasets there is evidence that these CM groups appropriately identify clients based on need for formal and informal support.

  8. Congenital cytomegalovirus (CMV) infection as a cause of permanent bilateral hearing loss: a quantitative assessment.

    Science.gov (United States)

    Grosse, Scott D; Ross, Danielle S; Dollard, Sheila C

    2008-02-01

    Congenital cytomegalovirus (CMV) infection is a cause of sensorineural hearing loss (SNHL) in children, but the magnitude of its contribution is uncertain. Quantifying the impact of congenital CMV infection requires an evidence-based assessment using a standard case definition of hearing loss. To determine the frequency of bilateral moderate to profound SNHL in children with congenital CMV infection and to estimate the CMV-attributable fraction of bilateral moderate to profound SNHL. A systematic review of studies of children with congenital CMV infection ascertained in an unbiased manner through universal newborn screening for CMV using viral culture in urine or saliva specimens in combination with a review of the literature on congenital CMV infection and hearing loss, including articles of all types. Approximately, 14% of children with congenital CMV infection develop SNHL of some type, and 3-5% develop bilateral moderate to profound SNHL. Among all children with bilateral moderate to profound SNHL, we estimate that 15-20% of cases are attributable to congenital CMV infection. Congenital CMV infection is one of the most important causes of hearing loss in young children, second only to genetic mutations, and is potentially preventable.

  9. Radiographic prognostic factors determining spontaneous space closure after loss of the permanent first molar.

    Science.gov (United States)

    Patel, Sameer; Ashley, Paul; Noar, Joseph

    2017-04-01

    Permanent first molars (PFM) with a poor prognosis are routinely extracted in children throughout the United Kingdom. National guidelines suggest that to achieve spontaneous closure for the mandibular arch, the PFM should be extracted at 8 to 10 years of age, during bifurcation formation of the second molar. The literature is of limited quality and has suggested alternative variables that may be associated with successful space closure. Our aim was to investigate the radiographic prognostic factors associated with space closure after extraction of PFM. Two objectives of the research are reported in this article: to determine factors that might predict space closure of the second molar after extraction of the PFM, and to develop a tool kit to aid clinical decision making. We assessed 148 maxillary and 153 mandibular PFM extracted from 81 participants retrospectively. Dental age, second molar developmental stage, second premolar and second molar angulations, and presence or absence of the third molar were assessed on the preextraction orthopantomograms. Outcome was assessed via visual examination, study models, or radiographs. Closure occurred in 89.9% of the maxillary and 49.0% of the mandibular quadrants. Dental age was statistically, but not clinically, significant in the maxillary arch (P space closure. The developed tool kit requires further validity testing. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  10. Perceived overprotection, instrumental support and rehabilitation use in elders with vision loss: a longitudinal perspective.

    Science.gov (United States)

    Cimarolli, Verena R; Boerner, Kathrin; Reinhardt, Joann P; Horowitz, Amy

    2013-01-01

    This study's purpose was to investigate changes in perceived overprotection - a problematic aspect of close relationships - over time in relationship to instrumental support receipt and vision rehabilitation service use in a sample of older adults with vision impairment. Participants were 584 older adults with chronic vision impairment who were interviewed three times over a 12-month period. Longitudinal data were analysed using a latent growth curve methodology to examine change over time in perceived overprotection and instrumental support in relation to vision rehabilitation service use. Self-reported levels of overprotection and receipt of instrumental support. Results. Over time perceived overprotection increased but not instrumental support. While perceived overprotection was positively associated with instrumental support initially, over time this relationship did not emerge. Perceived overprotection and instrumental support functioned as predictors of vision rehabilitation hours. However, over time vision rehabilitation service use did not influence these social supports. Perceived overprotection increases over time, yet this change is unaffected by rehabilitation service use and instrumental support. Both family members and elders need to be involved in the vision rehabilitation process and educated about how some level of independence can be regained.

  11. An unusual complication of combined gonioscopy-assisted transluminal trabeculotomy and phacoemulsification: vision loss due to intracapsular hematoma.

    Science.gov (United States)

    Yalinbas, Duygu; Aktas, Zeynep; Hepsen, İbrahim; Dilekmen, Nilay

    2017-09-23

    To report two cases with an acute vision loss due to intracapsular hemorrhage (hematoma) after an uncomplicated gonioscopy-assisted transluminal trabeculotomy (GATT) combined with phacoemulsification surgery. Case report. Seventy-six-year-old male and 75-year-old female patients with cataract and pseudoexfoliative glaucoma (XFG) uncontrolled with maximum medical therapy both underwent GATT combined with phacoemulsification. Shortly after the surgery, intracapsular hematoma behind the intraocular lens (IOL) were noted in both patients. Hematoma cleared in both of them via IOL extraction-anterior vitrectomy and YAG-laser capsulotomy, respectively. Hematoma cleared in both patients without any surgical complications. Vision loss due to unclearing intracapsular hematoma might be an early complication of combined GATT and phacoemulsification surgery.

  12. Limitations and Constraints of Eddy-Current Loss Models for Interior Permanent-Magnet Motors with Fractional-Slot Concentrated Windings

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    2017-03-01

    Full Text Available This paper analyzes and compares models for predicting average magnet losses in interior permanent-magnet motors with fractional-slot concentrated windings due to harmonics in the armature reaction (assuming sinusoidal phase currents. Particularly, loss models adopting different formulations and solutions to the Helmholtz equation to solve for the eddy currents are compared to a simpler model relying on an assumed eddy-current distribution. Boundaries in terms of magnet dimensions and angular frequency are identified (numerically and using an identified approximate analytical expression to aid the machine designer whether the more simple loss model is applicable or not. The assumption of a uniform flux-density variation (used in the loss models is also investigated for the case of V-shaped and straight interior permanent magnets. Finally, predicted volumetric loss densities are exemplified for combinations of slot and pole numbers common in automotive applications.

  13. Braille Reading Accuracy of Students Who Are Visually Impaired: The Effects of Gender, Age at Vision Loss, and Level of Education

    Science.gov (United States)

    Argyropoulos, Vassilis; Papadimitriou, Vassilios

    2015-01-01

    Introduction: The present study assesses the performance of students who are visually impaired (that is, those who are blind or have low vision) in braille reading accuracy and examines potential correlations among the error categories on the basis of gender, age at loss of vision, and level of education. Methods: Twenty-one visually impaired…

  14. Cost effectiveness of strategies to combat vision and hearing loss in sub-Saharan Africa and South East Asia: mathematical modelling study.

    NARCIS (Netherlands)

    Baltussen, R.M.; Smith, A.

    2012-01-01

    OBJECTIVE: To determine the relative costs, effects, and cost effectiveness of selected interventions to control cataract, trachoma, refractive error, hearing loss, meningitis and chronic otitis media. DESIGN: Cost effectiveness analysis of or combined strategies for controlling vision and hearing

  15. Impairments to Vision

    Science.gov (United States)

    ... an external Non-Government web site. Impairments to Vision Normal Vision Diabetic Retinopathy Age-related Macular Degeneration In this ... pictures, fixate on the nose to simulate the vision loss. In diabetic retinopathy, the blood vessels in ...

  16. A treatable cause of myelopathy and vision loss mimicking neuromyelitis optica spectrum disorder: late-onset biotinidase deficiency.

    Science.gov (United States)

    Yilmaz, Sanem; Serin, Mine; Canda, Ebru; Eraslan, Cenk; Tekin, Hande; Ucar, Sema Kalkan; Gokben, Sarenur; Tekgul, Hasan; Serdaroglu, Gul

    2017-06-01

    Biotinidase deficiency is characterized by severe neurological manifestations as hypotonia, lethargy, ataxia, hearing loss, seizures and developmental retardation in its classical form. Late-onset biotinidase deficiency presents distinctly from the classical form such as limb weakness and vision problems. A 14-year-old boy presented with progressive vision loss and upper limb weakness. The patient was initiated steroid therapy with a preliminary diagnosis of neuromyelitis optica spectrum disorder due to the craniospinal imaging findings demonstrating optic nerve, brainstem and longitudinally extensive spinal cord involvement. Although the patient exhibited partial clinical improvement after pulse steroid therapy, craniocervical imaging performed one month after the initiation of steroid therapy did not show any regression. The CSF IgG index was <0.8 (normal: <0.8), oligoclonal band and aquaporin-4 antibodies were negative. Metabolic investigations revealed a low biotinidase enzyme activity 8% (0.58 nmoL/min/mL; normal range: 4.4 to 12). Genetic testing showed c.98-104delinsTCC and p.V457 M mutations in biotinidase (BTD) gene. At the third month of biotin replacement therapy, control craniospinal MRI demonstrated a complete regression of the lesions. The muscle strength of the case returned to normal. His visual acuity was 7/10 in the left eye and 9/10 in the right. The late-onset form of the biotinidase deficiency should be kept in mind in all patients with myelopathy with or without vision loss, particularly in those with inadequate response to steroid therapy. The family screening is important to identify asymptomatic individuals and timely treatment.

  17. Atypical Wernicke′s syndrome sans encephalopathy with acute bilateral vision loss due to post-chiasmatic optic tract edema

    Directory of Open Access Journals (Sweden)

    Soaham Dilip Desai

    2014-01-01

    Full Text Available A middle aged male presented with acute bilateral vision loss, 4 weeks after undergoing gastric bypass surgery for gastric carcinoma. He had normal sensorium, fundoscopy, normal pupillary reaction to light, but had mild opthalmoparesis and nystagmus with ataxia. Magnetic resonance imaging of the brain revealed post-chiasmatic optic tract edema along with other classical features of Wernicke′s syndrome. Thiamine supplementation leads to complete resolution of clinical as well as imaging findings. In appropriate clinical settings, a high index of suspicion and early treatment are essential for managing Wernicke′s syndrome even in patients with atypical clinical and imaging presentation.

  18. Increased steroidogenesis promotes early-onset and severe vision loss in females with OPA1 dominant optic atrophy

    DEFF Research Database (Denmark)

    Sarzi, Emmanuelle; Seveno, Marie; Angebault, Claire

    2016-01-01

    levels of steroid precursor pregnenolone in females, causing an early-onset vision loss, abolished by ovariectomy. In addition, steroid production in retina is also increased which, in conjunction with high circulating levels, impairs estrogen receptor expression and mitochondrial respiratory complex IV...... tested the hypothesis of deregulated steroid production in retina due to a disease-causing OPA1 mutation and its contribution to the visual phenotypic variations. Using the mouse model carrying the human recurrent OPA1 mutation, we disclosed that Opa1 haploinsufficiency leads to very high circulating...

  19. Black patients sustain vision loss while White and South Asian patients gain vision following delamination or segmentation surgery for tractional complications associated with proliferative diabetic retinopathy.

    Science.gov (United States)

    Mastropasqua, R; Luo, Y H-L; Cheah, Y S; Egan, C; Lewis, J J; da Cruz, L

    2017-10-01

    PurposeThis retrospective comparative case series aims to determine whether patient ethnicity (White versus South Asian versus Black) is related to the outcome of surgical treatment for traction complications of severe proliferative diabetic retinopathy (PDR).SettingMoorfields Eye Hospital London, UK.MethodsAll patients who underwent vitrectomy with, delamination and/or segmentation for PDR over a 5-year period (2009-2014) were reviewed retrospectively. Patients were divided into White, South Asian or Black groups, and their age, gender, HbA1C and type of diabetes were recorded. A total of 484 patients (253 White, 117 South Asian, 114 Black) were included. Twenty-one patients were excluded due to inadequate documentation.OutcomesLogMAR Visual acuity (converted from Snellen) (VA), was recorded pre-operatively and ~6 months post surgery (range 5-8 months). Surgical outcome was classified according to the type and duration of tamponade required post-operatively.ResultsPre-operative VA and HbA1C values were similar across all three ethnic groups (P=0.64 and 0.569, respectively). Change in VA (mean±SD) was 0.41±0.78, 0.14±0.76 and -0.26±0.57 in White, South Asian and Black patient groups respectively (PAsian patient groups.ConclusionsThis study demonstrates that Black patients on average lose vision following delamination surgery for traction complications of PDR while White and South Asian patients gain vision. The same group is also at higher risk of retaining silicone more than 6 months after surgery. This difference remains even when corrected for glycaemic control. The higher risk of visual loss and long-term retention of silicone oil in black patients requires further investigation. If these results are confirmed, surgeons should consider their patients' ethnicity before proceeding with surgical treatment of diabetic tractional detachment.

  20. Accommodative spasm with bilateral vision loss due to untreated intermittent exotropia in an adult.

    Science.gov (United States)

    Shanker, V; Ganesh, S; Sethi, S

    2012-01-01

    Intermittent exotropia (IXT) is an exodeviation intermittently controlled by fusional mechanisms. Patients with IXT may present with asthenopic symptoms, blurred vision, headaches, diplopia or visual confusion and reading difficulties; especially after prolonged periods of near work. To report the presentation and management of a young adult with intractable accommodative spasm secondary to long standing intermittent exotropia. The patient was found to have bilateral accommodative spasm with high pseudomyopia and severe impairment of vision. There was a tendency for recurrence with discontinuation of cycloplegics. A total relief of symptoms was noticed after strabismus surgery was undertaken for the exotropia. A detailed orthoptic evaluation with emphasis on recognizing accommodative spasm as an unusual presentation of IXT, could aid in appropriate diagnosis and treatment of such cases. © NEPjOPH.

  1. Pediatric Low Vision

    Science.gov (United States)

    ... Asked Questions Español Condiciones Chinese Conditions Pediatric Low Vision What is Low Vision? Partial vision loss that cannot be corrected causes ... and play. What are the signs of Low Vision? Some signs of low vision include difficulty recognizing ...

  2. Neurologic state transitions in the eye and brain: kinetics of loss and recovery of vision and consciousness.

    Science.gov (United States)

    Whinnery, Typ; Forster, Estrella M

    2015-01-01

    Visual alterations, peripheral light loss (PLL) and blackout (BO), are components of acceleration (+Gz) induced loss of consciousness (LOC) and recovery of consciousness (ROC). The kinetics of loss of vision (LOV) and recovery of vision (ROV) were determined utilizing ocular pressure induced retinal ischemia and compared to the kinetics of LOC and ROC resulting from +Gz-induced cephalic nervous system (CPNS) ischemia. The time from self-induced retinal ischemia in completely healthy subjects (N = 104) to the onset of PLL and complete BO was measured. The time from release of ocular pressure, with return of normal retinal circulation, to the time for complete recovery of visual fields was also measured. The kinetics of pressure induced LOV and ROV was compared with previously developed kinetics of +Gz-induced LOC and ROC focusing on the rapid onset, vertical arm, of the +Gz-induced LOC and ROC curves. The time from onset of increased ocular pressure, immediately inducing retinal ischemia, to PLL was 5.04 s with the time to BO being 8.73 s. Complete recovery of the visual field from BO following release of ocular pressure, immediately abolishing retinal ischemia, was 2.74 s. These results confirm experimental findings that visual loss is frequently not experienced prior to LOC during exposure to rapid onset, high levels of +Gz-stress above tolerance. Offset of pressure induced retinal ischemia to ROV was 2.74 s, while the time from offset of +Gz-induced CPNS ischemia to ROC was 5.29 s. Recovery of retinal function would be predicted to be complete before consciousness is regained following +Gz-induced LOC. Ischemia onset time normalization in neurologic tissues permits comparison between different stress-induced times to altered function. The +Gz-time tolerance curves for LOV and LOC provide comparison and integration of neurologic state transition kinetics in the retina and CPNS.

  3. What Is Low Vision?

    Science.gov (United States)

    ... Your Rights Training Resources Workplace Technology CareerConnect Stories Working as a Senior with Vision Loss For Seniors Age-Related Vision ... Changes Health and Aging Retirement Living Continuing to Work as a Senior with Vision Loss Get Connected About VisionAware Join ...

  4. Short-term Vision Loss Following Whipple Surgery: A Case Report.

    Science.gov (United States)

    Gollapalli, Lakshman; Kumar, Aashish J; Sood, Kunal; Muppuri, Rudram

    2017-04-15

    Occipital seizures may result in visual deficits and may be an ictal or postictal phenomenon. A 71-year-old woman underwent pancreatoduodenectomy (Whipple procedure). During recovery in the postanesthesia care unit, the patient complained of blindness. Upon transfer to the intensive care unit, an electroencephalogram indicated bilateral occipital and hemispheric seizure activity. The patient was treated with antiseizure medication, and vision normalized within 3 days. Subtherapeutic concentration of free phenytoin was confirmed. Our experience suggests that electroencephalogram evaluation should be considered in the workup of postoperative patients who present with acute-onset blindness and in whom the cause remains ambiguous even in the absence of obvious clinical signs of seizures.

  5. Losses of functional opsin genes, short-wavelength cone photopigments, and color vision--a significant trend in the evolution of mammalian vision.

    Science.gov (United States)

    Jacobs, Gerald H

    2013-03-01

    All mammalian cone photopigments are derived from the operation of representatives from two opsin gene families (SWS1 and LWS in marsupial and eutherian mammals; SWS2 and LWS in monotremes), a process that produces cone pigments with respective peak sensitivities in the short and middle-to-long wavelengths. With the exception of a number of primate taxa, the modal pattern for mammals is to have two types of cone photopigment, one drawn from each of the gene families. In recent years, it has been discovered that the SWS1 opsin genes of a widely divergent collection of eutherian mammals have accumulated mutational changes that render them nonfunctional. This alteration reduces the retinal complements of these species to a single cone type, thus rendering ordinary color vision impossible. At present, several dozen species from five mammalian orders have been identified as falling into this category, but the total number of mammalian species that have lost short-wavelength cones in this way is certain to be much larger, perhaps reaching as high as 10% of all species. A number of circumstances that might be used to explain this widespread cone loss can be identified. Among these, the single consistent fact is that the species so affected are nocturnal or, if they are not technically nocturnal, they at least feature retinal organizations that are typically associated with that lifestyle. At the same time, however, there are many nocturnal mammals that retain functional short-wavelength cones. Nocturnality thus appears to set the stage for loss of functional SWS1 opsin genes in mammals, but it cannot be the sole circumstance.

  6. Overview of Usher's Syndrome: Congenital Deafness and Progressive Loss of Vision

    Science.gov (United States)

    Vernon, McCay

    1974-01-01

    Usher's syndrome, a genetic condition causing congenital profound hearing loss and a progressive blindness due to retinitis pigmentosa, affects an estimated three to six percent of children in educational and rehabilitative programs for the hearing impaired. (Author)

  7. Prevalence and causes of vision loss in Central and South Asia: 1990-2010.

    Science.gov (United States)

    Jonas, Jost B; George, Ronnie; Asokan, Rashima; Flaxman, Seth R; Keeffe, Jill; Leasher, Janet; Naidoo, Kovin; Pesudovs, Konrad; Price, Holly; Vijaya, Lingam; White, Richard A; Wong, Tien Y; Resnikoff, Serge; Taylor, Hugh R; Bourne, Rupert R A

    2014-05-01

    To examine the prevalence, patterns and trends of vision impairment and its causes from 1990 to 2010 in Central and South Asia. Based on the Global Burden of Diseases Study 2010 and ongoing literature searches, we examined prevalence and causes of moderate and severe vision impairment (MSVI; presenting visual acuity Central Asia, the estimated age-standardised prevalence of blindness decreased from 0.4% (95% CI 0.3% to 0.6%) to 0.2% (95% CI 0.2% to 0.3%) and of MSVI from 3.0% (95% CI 1.9% to 4.7%) to 1.9% (95% CI 1.2% to 3.2%), and in South Asia blindness decreased from 1.7% (95% CI 1.4% to 2.1%) to 1.1% (95% CI 0.9% to 1.3%) and MSVI from 8.9% (95% CI 6.9% to 10.9%) to 6.4% (95% CI 5.2% to 8.2%). In 2010, 135 000 (95% CI 99,000 to 194,000) people were blind in Central Asia and 10,600,000 (95% CI 8,397,000 to 12,500,000) people in South Asia. MSVI was present in 1,178,000 (95% CI 772,000 to 2,243,000) people in the Central Asia, and in 71,600,000 (95% CI 57,600,000 to 92,600,000) people in South Asia. Women were generally more often affected than men. The leading causes of blindness (cataract) and MSVI (undercorrected refractive error) did not change from 1990 to 2010. The prevalence of blindness and MSVI in South Asia is still three times higher than in Central Asia and globally, with women generally more often affected than women. In both regions, cataract and undercorrected refractive error were major causes of blindness and MSVI.

  8. Bilateral vision loss due to Leber's hereditary optic neuropathy after long-term alcohol, nicotine and drug abuse.

    Science.gov (United States)

    Maass, Johanna; Matthé, Egbert

    2018-04-01

    Leber's hereditary optic neuropathy is relatively rare, and no clinical pathognomonic signs exist. We present a rare case of bilateral vision loss of a patient with multiple drug abuse in the history. A 31-year-old man presented with a history of progressive, decreased vision in both eyes for 6 month. On examination, his visual acuity was hand motion in both eyes. Funduscopy demonstrated a temporal pallor of the optic disc. Goldmann visual field perimetry showed a crescent visual field in the right eye and a circular decrease to less than 50 ° in the left eye. Electroretinogram showed a scotopic b-wave amplitude reduction. Optical coherence tomographies, Heidelberg Retina tomography, visual evoked potentials, and magnetic resonance imaging with contrast as well as blood tests were normal. The patient reported to consume various kinds of drugs as well as recreational drug use and alcohol consumption since he was 16 years old. We started a hemodilution therapy, believing the patient suffered from a bilateral, toxic optic neuropathy due to his lifestyle. Laboratory results later on showed Leber's hereditary optic neuropathy. Leber's hereditary optic neuropathy is a rare disease without a typical, pathognomonic presentation. Even though the patient gave good reasons for a toxic optic neuropathy, one should never stop to test for other diseases.

  9. [(Neurological CPC-59). A 65-year-old man with a history of gastric cancer who presented progressive loss of vision, memory loss and consciousness disturbance].

    Science.gov (United States)

    Nohara, C; Matsumine, H; Suzuki, K; Saito, A; Ohtaka, M; Mori, H; Suda, K; Kondo, T; Hayakawa, M; Kanai, J; Mizuno, Y

    1997-11-01

    We report a 65-year-old man with progressive loss of vision and consciousness disturbance. The patient was well until his age of 63 when he was found to have a gastric cancer. He was treated by the tumor resection and chemotherapy; he was apparently well, but hepatic metastases were found in the next year (1996). In June, 1996, he noted an onset of blurred vision more on the left. He was admitted to the ophthalmology service of our hospital on July 14, 1996. His vision was 0.8 on the right and 0.15 on the left. He was treated with oral prednisolone with slight improvement. He was also found to have IgM kappa-type monoclonal gammopathy; Bence-Jones protein was positive and a bone marrow aspiration revealed that approximately 10% of bone marrow cells were atypical plasma cells. His vision had progressively got worse and he became blind by the end of October 1996. A chest X-ray and cranial CT scan revealed multiple abnormal nodular densities. In the middle of November 1996, he became confused, disoriented and agitated. His mental symptoms had progressively became worse, and a neurologic consultation was asked on December 10, 1996. Neurologic examination revealed that he was somnolent with decreased attention to his surroundings. He showed marked disorientation and memory loss. Higher cerebral functions appeared intact. He was able to recognize only light and dark. Pupils were moderately dilated with very sluggish light reflex remained. Vertical gaze was moderately restricted and horizontal nystagmus was noted upon left and right lateral gaze. The remaining of the neurologic examination were unremarkable. General physical examination revealed hepatosplenomegaly; the liver was palpable by 3 cm below the right costal margin. Laboratory examination revealed anemia (Hb10.1 g/dl) and thrombocytopenia (43,000/microliter). A cranial CT scan and MRI revealed a mass lesion in involving the chiasmatic and bilateral hypothalamic areas. The tumor showed intense homogeneous

  10. Revisiting Postoperative Vision Loss following Non-Ocular Surgery: A Short Review of Etiology and Legal Considerations

    Directory of Open Access Journals (Sweden)

    Ehud Mendel

    2017-06-01

    Full Text Available Postoperative vision loss (POVL following non-ocular surgery is a serious complication where the causes are not fully understood. Studies have identified several causes of POVL as well as risk factors and prevention strategies. POVL research is made difficult by the fact that cases are often subject to malpractice claims, resulting in a lack of public access to case reports. This literature review was conducted in order to identify legal issues as a major barrier to studying POVL and address how this affects current knowledge. Informed consent provides an opportunity to overcome legal challenges by reducing malpractice litigation through educating the patient on this outcome. Providing pertinent information regarding POVL during the informed consent process has potential to reduce malpractice claims and increase available clinical information.

  11. Gender Differences and the Risk of Falls in Individuals with Profound Vision Loss

    Science.gov (United States)

    Ray, Christopher T.; Wolf, Steven L.

    2010-01-01

    Adults with visual impairments experience a loss of balance and mobility, which presents a barrier to independence and is associated with the fear of falling. The purpose of this study was to determine the extent to which visual status, age, gender, body mass index (BMI), and the strength of quadriceps and hamstrings contribute to compromised…

  12. Natural Compounds from Saffron and Bear Bile Prevent Vision Loss and Retinal Degeneration

    Directory of Open Access Journals (Sweden)

    Laura Fernández-Sánchez

    2015-07-01

    Full Text Available All retinal disorders, regardless of their aetiology, involve the activation of oxidative stress and apoptosis pathways. The administration of neuroprotective factors is crucial in all phases of the pathology, even when vision has been completely lost. The retina is one of the most susceptible tissues to reactive oxygen species damage. On the other hand, proper development and functioning of the retina requires a precise balance between the processes of proliferation, differentiation and programmed cell death. The life-or-death decision seems to be the result of a complex balance between pro- and anti-apoptotic signals. It has been recently shown the efficacy of natural products to slow retinal degenerative process through different pathways. In this review, we assess the neuroprotective effect of two compounds used in the ancient pharmacopoeia. On one hand, it has been demonstrated that administration of the saffron constituent safranal to P23H rats, an animal model of retinitis pigmentosa, preserves photoreceptor morphology and number, the capillary network and the visual response. On the other hand, it has been shown that systemic administration of tauroursodeoxycholic acid (TUDCA, the major component of bear bile, to P23H rats preserves cone and rod structure and function, together with their contact with postsynaptic neurons. The neuroprotective effects of safranal and TUDCA make these compounds potentially useful for therapeutic applications in retinal degenerative diseases.

  13. Vision deficits precede structural losses in a mouse model of mitochondrial dysfunction and progressive retinal degeneration.

    Science.gov (United States)

    Laliberté, Alex M; MacPherson, Thomas C; Micks, Taft; Yan, Alex; Hill, Kathleen A

    2011-12-01

    Current animal models of retinal disease often involve the rapid development of a retinal disease phenotype; however, this is at odds with age-related diseases that take many years to manifest clinical symptoms. The present study was performed to examine an apoptosis-inducing factor (Aif)-deficient model, the harlequin carrier mouse (X(hq)X), and determine how mitochondrial dysfunction and subsequent accelerated aging affect the function and structure of the mouse retina. Vision and eye structure for cohorts of 6 X(hq)X and 6 wild type mice at 3, 11, and 15 months of age were studied using in vivo electroretinography (ERG), and optical coherence tomography (OCT). Retinal superoxide levels were determined in situ using dihydroethidium (DHE) histochemistry. Retinal cell counts were quantified post mortem using hematoxylin and eosin (H&E) staining. ERG analysis of X(hq)X retinal function indicated a reduction in b-wave amplitude significant at 3 months of age (p retina (p retina may account for the early and significant reduction in retinal function. This remodeling of retinal neurochemistry in response to stress may be a relevant mechanism in the progression of normal retinal aging and early stages of some retinal degenerative diseases. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Natural Compounds from Saffron and Bear Bile Prevent Vision Loss and Retinal Degeneration.

    Science.gov (United States)

    Fernández-Sánchez, Laura; Lax, Pedro; Noailles, Agustina; Angulo, Antonia; Maneu, Victoria; Cuenca, Nicolás

    2015-07-31

    All retinal disorders, regardless of their aetiology, involve the activation of oxidative stress and apoptosis pathways. The administration of neuroprotective factors is crucial in all phases of the pathology, even when vision has been completely lost. The retina is one of the most susceptible tissues to reactive oxygen species damage. On the other hand, proper development and functioning of the retina requires a precise balance between the processes of proliferation, differentiation and programmed cell death. The life-or-death decision seems to be the result of a complex balance between pro- and anti-apoptotic signals. It has been recently shown the efficacy of natural products to slow retinal degenerative process through different pathways. In this review, we assess the neuroprotective effect of two compounds used in the ancient pharmacopoeia. On one hand, it has been demonstrated that administration of the saffron constituent safranal to P23H rats, an animal model of retinitis pigmentosa, preserves photoreceptor morphology and number, the capillary network and the visual response. On the other hand, it has been shown that systemic administration of tauroursodeoxycholic acid (TUDCA), the major component of bear bile, to P23H rats preserves cone and rod structure and function, together with their contact with postsynaptic neurons. The neuroprotective effects of safranal and TUDCA make these compounds potentially useful for therapeutic applications in retinal degenerative diseases.

  15. Hypothalamic-pituitary sarcoidosis with vision loss and hypopituitarism: case series and literature review.

    Science.gov (United States)

    Anthony, Jeremy; Esper, Gregory J; Ioachimescu, Adriana

    2016-02-01

    Hypothalamic-pituitary (HP) neurosarcoidosis (NS) accounts for 0.5 % cases of sarcoidosis and 1 % of HP masses. Correlative data on endocrine and neurological outcomes is lacking. Retrospective case series and literature review of presentation, treatment and outcome of HP NS. Our series includes 4 men, ages 34-59, followed for a median of 7.3 years (range 1.5-17). All had optic neuropathy, multiple pituitary hormone abnormalities (PHAs) and other organ involvement by sarcoidosis (lung, sino-nasal, brain/spine and facial nerve). Two patients had central diabetes insipidus and one impaired thirst with polydipsia. After treatment with high-dose glucocorticoids, optic neuropathy improved in one case and stabilized in the others. After treatment, HP lesions improved radiologically, but PHAs persisted in all cases. Review of four published series on HP NS in addition to ours yielded 46 patients, age 37 ± 11.8 years, 65 % male. PHAs consisted of anterior hypopituitarism (LH/FSH 88.8 %, TSH 67.4 %, GH 50.0 %, ACTH 48.8 %), hyperprolactinemia (48.8 %) and diabetes insipidus (65.2 %). PHAs were the first sign of disease in 54.3 % patients. Vision problems occurred in 28.3 % patients, but optic neuropathy was not well documented in previous series. Most patients (93.5 %) received high-dose glucocorticoids followed by taper; 50 % also received other immunomodulators, including methotrexate, mycophenolate mofetil, cyclosporine, azathioprine, infliximab and hydrochloroquine. Only 13 % patients showed improvement in PHAs. All-cause mortality was 8.7 %. HP NS is a serious disease requiring multidisciplinary treatment and lifelong follow-up. Prospective multicentric studies are needed to determine a more standardized approach to HP NS and outline predictors of disease outcome.

  16. TrkB Activators for the Treatment of Traumatic Vision Loss

    Science.gov (United States)

    2017-06-01

    metrhod for deteremining retinal ganglion cell loss. Poster Abstract 16, ISER Glaucoma Symposium. Chrenek, Micah A.; Sellers, Jana; Foster...of the reaction mixture followed by dry loading of the unwieldy crude onto a silica gel column allowed for chromatographic separation with ethyl...2006).  Demographic  and  cognitive   predictors  of  long‐term  psychosocial  outcome  following  traumatic  brain  injury.  J  Int  Neuropsychol Soc

  17. Modeling and Maximum Power Point Tracking Control of Wind Generating Units Equipped with Permanent Magnet Synchronous Generators in Presence of Losses

    Directory of Open Access Journals (Sweden)

    Andrea Bonfiglio

    2017-01-01

    Full Text Available This paper focuses on the modeling of wind turbines equipped with direct drive permanent magnet synchronous generators for fundamental frequency power system simulations. Specifically, a procedure accounting for the system active power losses to initialize the simulation starting from the load flow results is proposed. Moreover, some analytical assessments are detailed on typical control schemes for fully rated wind turbine generators, thereby highlighting how active power losses play a fundamental role in the effectiveness of the wind generator control algorithm. Finally, the paper proposes analytical criteria to design the structure and the parameters of the regulators of the wind generator control scheme. Simulations performed with Digsilent Power Factory validated the proposed procedure, highlighting the impact of active power losses on the characterization of the initial steady state and that the simplifying assumptions done in order to synthesize the controllers are consistent with the complete modeling performed by the aforementioned power system simulator.

  18. Development of Correlations for Windage Power Losses Modeling in an Axial Flux Permanent Magnet Synchronous Machine with Geometrical Features of the Magnets

    Directory of Open Access Journals (Sweden)

    Alireza Rasekh

    2016-11-01

    Full Text Available In this paper, a set of correlations for the windage power losses in a 4 kW axial flux permanent magnet synchronous machine (AFPMSM is presented. In order to have an efficient machine, it is necessary to optimize the total electromagnetic and mechanical losses. Therefore, fast equations are needed to estimate the windage power losses of the machine. The geometry consists of an open rotor–stator with sixteen magnets at the periphery of the rotor with an annular opening in the entire disk. Air can flow in a channel being formed between the magnets and in a small gap region between the magnets and the stator surface. To construct the correlations, computational fluid dynamics (CFD simulations through the frozen rotor (FR method are performed at the practical ranges of the geometrical parameters, namely the gap size distance, the rotational speed of the rotor, the magnet thickness and the magnet angle. Thereafter, two categories of formulations are defined to make the windage losses dimensionless based on whether the losses are mainly due to the viscous forces or the pressure forces. At the end, the correlations can be achieved via curve fittings from the numerical data. The results reveal that the pressure forces are responsible for the windage losses for the side surfaces in the air-channel, whereas for the surfaces facing the stator surface in the gap, the viscous forces mainly contribute to the windage losses. Additionally, the results of the parametric study demonstrate that the overall windage losses in the machine escalate with an increase in either the rotational Reynolds number or the magnet thickness ratio. By contrast, the windage losses decrease once the magnet angle ratio enlarges. Moreover, it can be concluded that the proposed correlations are very useful tools in the design and optimizations of this type of electrical machine.

  19. Severe structural and functional visual system damage leads to profound loss of vision-related quality of life in patients with neuromyelitis optica spectrum disorders.

    Science.gov (United States)

    Schmidt, Felix; Zimmermann, Hanna; Mikolajczak, Janine; Oertel, Frederike C; Pache, Florence; Weinhold, Maria; Schinzel, Johann; Bellmann-Strobl, Judith; Ruprecht, Klemens; Paul, Friedemann; Brandt, Alexander U

    2017-01-01

    Neuromyelitis optica spectrum disorders (NMOSD) are characterized by devastating optic neuritis attacks causing more structural damage and visual impairment than in multiple sclerosis (MS). The objective of this study was to compare vision-related quality of life in NMOSD and MS patients and correlate it to structural retinal damage and visual function. Thirty-one NMOSD and 31 matched MS patients were included. Vision-related quality of life was assessed with the 39-item National Eye Institute Visual Function Questionnaire (NEI-VFQ). All patients underwent retinal optical coherence tomography and visual acuity and contrast sensitivity measurements. Vision-related quality of life was reduced in NMOSD compared to MS patients. This difference was driven by a higher incidence of bilateral and more severe optic neuritis in the NMOSD group. Retinal thinning and visual impairment were significantly greater in the NMOSD cohort. Lower vision-related quality of life was associated with more retinal damage and reduced visual function as assessed by visual acuity and contrast sensitivity. NMOSD-related bilateral ON-attacks cause severe structural damage and visual impairment that lead to severe loss of vision-related quality of life. The NEI-VFQ is a helpful tool to monitor vision-related quality of life in NMOSD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Impact of Early Intervention on Expressive and Receptive Language Development among Young Children with Permanent Hearing Loss

    Science.gov (United States)

    Meinzen-Derr, Jareen; Wiley, Susan; Choo, Daniel I.

    2011-01-01

    Along with early detection, early intervention (EI) is critical for children identified with hearing loss. Evidence indicates that many children with sensorineural hearing loss experience improved language abilities if EI services were initiated at an "early" age. The present study's objectives were to determine the impact of a state EI program on…

  1. Evaluation of a Portable Collision Warning Device for Patients With Peripheral Vision Loss in an Obstacle Course.

    Science.gov (United States)

    Pundlik, Shrinivas; Tomasi, Matteo; Luo, Gang

    2015-04-01

    A pocket-sized collision warning device equipped with a video camera was developed to predict impending collisions based on time to collision rather than proximity. A study was conducted in a high-density obstacle course to evaluate the effect of the device on collision avoidance in people with peripheral field loss (PFL). The 41-meter-long loop-shaped obstacle course consisted of 46 stationary obstacles from floor to head level and oncoming pedestrians. Twenty-five patients with tunnel vision (n = 13) or hemianopia (n = 12) completed four consecutive loops with and without the device, while not using any other habitual mobility aid. Walking direction and device usage order were counterbalanced. Number of collisions and preferred percentage of walking speed (PPWS) were compared within subjects. Collisions were reduced significantly by approximately 37% (P < 0.001) with the device (floor-level obstacles were excluded because the device was not designed for them). No patient had more collisions when using the device. Although the PPWS were also reduced with the device from 52% to 49% (P = 0.053), this did not account for the lower number of collisions, as the changes in collisions and PPWS were not correlated (P = 0.516). The device may help patients with a wide range of PFL avoid collisions with high-level obstacles while barely affecting their walking speed.

  2. Blindness and vision loss

    Science.gov (United States)

    ... In the United States, the leading causes are: Accidents or injuries to the surface of the eye ( chemical burns or sports injuries) Diabetes Glaucoma Macular ... A.D.A.M.'s editorial policy , editorial process and privacy policy . A.D.A.M. is ...

  3. Vision Loss, Sudden

    Science.gov (United States)

    ... cornea (the clear layer in front of the iris and pupil), then the lens, and then the ... sudden start of symptoms may instead be sudden recognition. For example, a person with long-standing reduced ...

  4. Prevention of vision loss protects against age-related impairment in learning and memory performance in DBA/2J mice.

    Science.gov (United States)

    Wong, Aimée A; Brown, Richard E

    2013-01-01

    The DBA/2J mouse is a model of pigmentary glaucoma in humans as it shows age-related increases in intraocular pressure (IOP), retinal ganglion cell death and visual impairment. Previously, we showed that visual ability declines from 9 to 12 months of age and visual impairment is correlated with poor learning and memory performance in visuo-spatial tasks but not in tasks that do not depend on visual cues. To test the "sensory impairment" hypothesis of aging, which postulates that sensory impaired individuals are disadvantaged in their performance on psychometric tests as a direct result of difficulties in sensory perception, we treated DBA/2J mice with a conventional glaucoma medication used in humans (Timoptic-XE, 0.00, 0.25, or 0.50%) daily from 9 weeks to 12 months of age to determine whether prevention of vision loss prevented the decline in visuo-spatial learning and memory performance. At all ages tested (3, 6, 9, and 12 months of age), mice treated with Timoptic-XE (0.25 and 0.50%) maintained a high level of performance, while 12 month old control mice (0.00%) exhibited impaired performance in visually-dependent, but not non-visual tasks. These results demonstrate that when sensory function is preserved, cognitive performance is normalized. Thus, as in many aging humans, DBA/2J mice show age-related decrements in performance on visually presented cognitive tests, not because of cognitive impairment but as a direct consequence of poor visual ability. Our results demonstrate that age-related impairment in performance in visuo-spatial tasks in DBA/2J mice can be prevented by the preservation of visual ability.

  5. Prevention of vision loss protects against age-related impairment in learning and memory performance in DBA/2J mice

    Directory of Open Access Journals (Sweden)

    Aimee eWong

    2013-09-01

    Full Text Available The DBA/2J mouse is a model of pigmentary glaucoma in humans as it shows age‐related increases in intraocular pressure, retinal ganglion cell death and visual impairment. Previously, we showed that visual ability declines from 9 ‐12 months of age and visual impairment is correlated with poor learning and memory performance in visuo‐spatial tasks but not in tasks that do not depend on visual cues. To test the sensory impairment hypothesis of aging, which postulates that sensory impaired individuals are disadvantaged in their performance on psychometric tests as a direct result of difficulties in sensory perception, we treated DBA/2J mice with a conventional glaucoma medication used in humans (Timoptic‐XE, 0.00, 0.25 or 0.50% daily from 9 weeks to 12 months of age to determine whether prevention of vision loss prevented the decline in visuo-spatial learning and memory performance. At all ages tested (3, 6, 9 and 12 months of age, mice treated with Timoptic-XE (0.25 and 0.50% maintained a high level of performance, while 12 month old control mice (0.00% exhibited impaired performance in visually‐dependent, but not non‐visual tasks. These results demonstrate that when sensory function is preserved, cognitive performance is normalized. Thus, as in many aging humans, DBA/2J mice show age-related decrements in performance on visually presented cognitive tests, not because of cognitive impairment but as a direct consequence of poor visual ability. Our results demonstrate that age-related impairment in performance in visuo-spatial tasks in DBA/2J mice can be prevented by the preservation of visual ability.

  6. Characteristics of on-road driving performance of persons with central vision loss who use bioptic telescopes.

    Science.gov (United States)

    Wood, Joanne M; McGwin, Gerald; Elgin, Jennifer; Searcey, Karen; Owsley, Cynthia

    2013-05-01

    To compare the on-road driving performance of visually impaired drivers using bioptic telescopes with age-matched controls. Participants included 23 persons (mean age = 33 ± 12 years) with visual acuity of 20/63 to 20/200 who were legally licensed to drive through a state bioptic driving program, and 23 visually normal age-matched controls (mean age = 33 ± 12 years). On-road driving was assessed in an instrumented dual-brake vehicle along 14.6 miles of city, suburban, and controlled-access highways. Two backseat evaluators independently rated driving performance using a standardized scoring system. Vehicle control was assessed through vehicle instrumentation and video recordings used to evaluate head movements, lane-keeping, pedestrian detection, and frequency of bioptic telescope use. Ninety-six percent (22/23) of bioptic drivers and 100% (23/23) of controls were rated as safe to drive by the evaluators. There were no group differences for pedestrian detection, or ratings for scanning, speed, gap judgments, braking, indicator use, or obeying signs/signals. Bioptic drivers received worse ratings than controls for lane position and steering steadiness and had lower rates of correct sign and traffic signal recognition. Bioptic drivers made significantly more right head movements, drove more often over the right-hand lane marking, and exhibited more sudden braking than controls. Drivers with central vision loss who are licensed to drive through a bioptic driving program can display proficient on-road driving skills. This raises questions regarding the validity of denying such drivers a license without the opportunity to train with a bioptic telescope and undergo on-road evaluation.

  7. Scanning laser polarimetry, but not optical coherence tomography predicts permanent visual field loss in acute nonarteritic anterior ischemic optic neuropathy.

    Science.gov (United States)

    Kupersmith, Mark J; Anderson, Susan; Durbin, Mary; Kardon, Randy

    2013-08-15

    Scanning laser polarimetry (SLP) reveals abnormal retardance of birefringence in locations of the edematous peripapillary retinal nerve fiber layer (RNFL), which appear thickened by optical coherence tomography (OCT), in nonarteritic anterior ischemic optic neuropathy (NAION). We hypothesize initial sector SLP RNFL abnormalities will correlate with long-term regional visual field loss due to ischemic injury. We prospectively performed automated perimetry, SLP, and high definition OCT (HD-OCT) of the RNFL in 25 eyes with acute NAION. We grouped visual field threshold and RNFL values into Garway-Heath inferior/superior disc sectors and corresponding superior/inferior field regions. We compared sector SLP RNFL thickness with corresponding visual field values at presentation and at >3 months. At presentation, 12 eyes had superior sector SLP reduction, 11 of which had inferior field loss. Six eyes, all with superior field loss, had inferior sector SLP reduction. No eyes had reduced OCT-derived RNFL acutely. Eyes with abnormal field regions had corresponding SLP sectors thinner (P = 0.003) than for sectors with normal field regions. During the acute phase, the SLP-derived sector correlated with presentation (r = 0.59, P = 0.02) and with >3-month after presentation (r = 0.44, P = 0.02) corresponding superior and inferior field thresholds. Abnormal RNFL birefringence occurs in sectors corresponding to regional visual field loss during acute NAION when OCT-derived RNFL shows thickening. Since the visual field deficits show no significant recovery, SLP can be an early marker for axonal injury, which may be used to assess recovery potential at RNFL locations with respect to new treatments for acute NAION.

  8. Internet use and television viewing in children and its association with vision loss: a major public health problem

    Directory of Open Access Journals (Sweden)

    Abdulbari Bener

    2012-05-01

    Full Text Available Little is known about the distribution of eye and vision conditions among school children in Qatar. The aim of the study was to examine the effects of excessive internet use and television viewing on low vision and its prevalence with socio-demographic characteristics. This is a cross-sectional study which was carried out in the public and private schools of the Ministry of Education and Higher Education of the State of Qatar from September 2009 to April 2010. A total of 3200 students aged 6-18 years were invited to take part of whom 2586 (80.8% agreed. A questionnaire, that included questions about socio-demographic factors, internet use, and television viewing and computer games, co-morbid factors, and family history and vision assessment, was designed to collect information from the students. This was distributed by the school authorities. Of the school children studied (n=2586, 52.8% were girls and 47.2% boys. The overall prevalence of low vision was 15.2%. The prevalence of low vision was significantly higher in the age group 6-10 years (17.1%; P=0.05. Low vision was more prevalent among television viewers (17.2% than in infrequent viewers (14.0%. The proportion of children wearing glasses was higher in frequent internet users and television viewers (21.3%. Also, low vision without aid was higher in frequent viewers. The study findings revealed a greater prevalence of low vision among frequent internet users and television viewers. The proportion of children wearing glasses was higher among frequent viewers. The prevalence of low vision decreased with increasing age.

  9. Internet Use and Television Viewing in Children and its Association with Vision Loss: A Major Public Health Problem.

    Science.gov (United States)

    Bener, Abdulbari; Al-Mahdi, Huda S

    2012-03-07

    Little is known about the distribution of eye and vision conditions among school children in Qatar. The aim of the study was to examine the effects of excessive internet use and television viewing on low vision and its prevalence with socio-demographic characteristics. This is a cross-sectional study which was carried out in the public and private schools of the Ministry of Education and Higher Education of the State of Qatar from September 2009 to April 2010. A total of 3200 students aged 6-18 years were invited to take part of whom 2586 (80.8%) agreed. A questionnaire, that included questions about socio-demographic factors, internet use, and television viewing and computer games, co-morbid factors, and family history and vision assessment, was designed to collect information from the students. This was distributed by the school authorities. Of the school children studied (n=2586), 52.8% were girls and 47.2% boys. The overall prevalence of low vision was 15.2%. The prevalence of low vision was significantly higher in the age group 6-10 years (17.1%; P=0.05). Low vision was more prevalent among television viewers (17.2%) than in infrequent viewers (14.0%). The proportion of children wearing glasses was higher in frequent internet users and television viewers (21.3%). Also, low vision without aid was higher in frequent viewers. The study findings revealed a greater prevalence of low vision among frequent internet users and television viewers. The proportion of children wearing glasses was higher among frequent viewers. The prevalence of low vision decreased with increasing age.

  10. Refractive error, visual acuity and causes of vision loss in children in Shandong, China. The Shandong Children Eye Study.

    Directory of Open Access Journals (Sweden)

    Jian Feng Wu

    Full Text Available PURPOSE: To examine the prevalence of refractive errors and prevalence and causes of vision loss among preschool and school children in East China. METHODS: Using a random cluster sampling in a cross-sectional school-based study design, children with an age of 4-18 years were selected from kindergartens, primary schools, and junior and senior high schools in the rural Guanxian County and the city of Weihai. All children underwent a complete ocular examination including measurement of uncorrected (UCVA and best corrected visual acuity (BCVA and auto-refractometry under cycloplegia. Myopia was defined as refractive error of ≤-0.5 diopters (D, high myopia as ≤ -6.0D, and amblyopia as BCVA ≤ 20/32 without any obvious reason for vision reduction and with strabismus or refractive errors as potential reasons. RESULTS: Out of 6364 eligible children, 6026 (94.7% children participated. Prevalence of myopia (overall: 36.9 ± 0.6%;95% confidence interval (CI:36.0,38.0 increased (P<0.001 from 1.7 ± 1.2% (95%CI:0.0,4.0 in the 4-years olds to 84.6 ± 3.2% (95%CI:78.0,91.0 in 17-years olds. Myopia was associated with older age (OR:1.56;95%CI:1.52,1.60;P<0.001, female gender (OR:1.22;95%CI:1.08,1.39;P = 0.002 and urban region (OR:2.88;95%CI:2.53,3.29;P<0.001. Prevalence of high myopia (2.0 ± 0.2% increased from 0.7 ± 0.3% (95%CI:0.1,1.3 in 10-years olds to 13.9 ± 3.0 (95%CI:7.8,19.9 in 17-years olds. It was associated with older age (OR:1.50;95%CI:1.41,1.60;P<0.001 and urban region (OR:3.11;95%CI:2.08,4.66;P<0.001. Astigmatism (≥ 0.75D (36.3 ± 0.6%;95%CI:35.0,38.0 was associated with older age (P<0.001;OR:1.06;95%CI:1.04,1.09, more myopic refractive error (P<0.001;OR:0.94;95%CI:0.91,0.97 and urban region (P<0.001;OR:1.47;95%CI:1.31,1.64. BCVA was ≤ 20/40 in the better eye in 19 (0.32% children. UCVA ≤ 20/40 in at least one eye was found in 2046 (34.05% children, with undercorrected refractive error as cause in 1975 (32.9% children. Amblyopia

  11. Effect of Stabilization Heat Treatment on Time-Dependent Polarization Losses in Sintered Nd-Fe-B Permanent Magnets

    Directory of Open Access Journals (Sweden)

    Tuominen S.

    2013-01-01

    Full Text Available Some companies in the motor and generator industry utilizing sintered NdFeB magnets have adopted pre-ageing heat treatment in order to improve the stability of the magnets. The parameters of this stabilization heat treatment are based mainly on assumptions rather than on any published research results. In this work, the effects of pre-ageing treatment on the time-dependent polarization losses of two different types of commercial sintered NdFeB magnets were studied. The material showing the squarer J(H curve did not benefit from the pre-ageing treatment, since it seems to be stable under a certain critical temperature. In contrast, a stabilizing effect was observed in the material showing rounder J(H curve. After the stabilization heat treatment, the polarization of the magnets was found to be at lower level, but unchanged over a certain period of time. The length of this period depends on the temperature and the duration of the pre-ageing treatment. In addition, our analysis reveals that the stabilization heat treatment performed in an open circuit condition does not stabilize the magnet uniformly.

  12. Landing performance by low-time private pilots after the sudden loss of binocular vision - Cyclops II

    Science.gov (United States)

    Lewis, C. E., Jr.; Swaroop, R.; Mcmurty, T. C.; Blakeley, W. R.; Masters, R. L.

    1973-01-01

    Study of low-time general aviation pilots, who, in a series of spot landings, were suddenly deprived of binocular vision by patching either eye on the downwind leg of a standard, closed traffic pattern. Data collected during these landings were compared with control data from landings flown with normal vision during the same flight. The sequence of patching and the mix of control and monocular landings were randomized to minimize the effect of learning. No decrease in performance was observed during landings with vision restricted to one eye, in fact, performance improved. This observation is reported at a high level of confidence (p less than 0.001). These findings confirm the previous work of Lewis and Krier and have important implications with regard to aeromedical certification standards.

  13. A child's vision.

    Science.gov (United States)

    Nye, Christina

    2014-06-01

    Implementing standard vision screening techniques in the primary care practice is the most effective means to detect children with potential vision problems at an age when the vision loss may be treatable. A critical period of vision development occurs in the first few weeks of life; thus, it is imperative that serious problems are detected at this time. Although it is not possible to quantitate an infant's vision, evaluating ocular health appropriately can mean the difference between sight and blindness and, in the case of retinoblastoma, life or death. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. 3-D analysis of eddy current in permanent magnet of interior permanent magnet motors

    International Nuclear Information System (INIS)

    Kawase, Yoshihiro; Yamaguchi, Tadashi; Fukanaga, Hiromu; Ito, Shokichi

    2002-01-01

    Interior permanent magnet motors are widely used in various fields. However, in high-speed operations, it is important to decrease the eddy current loss in the permanent magnet. In order to decrease the eddy current loss, we propose to divide the permanent magnet. In this paper, we clarified the effect of division of permanent magnet on the eddy current loss using the 3-D finite element method. (Author)

  15. The role of vision processing in prosthetic vision.

    Science.gov (United States)

    Barnes, Nick; He, Xuming; McCarthy, Chris; Horne, Lachlan; Kim, Junae; Scott, Adele; Lieby, Paulette

    2012-01-01

    Prosthetic vision provides vision which is reduced in resolution and dynamic range compared to normal human vision. This comes about both due to residual damage to the visual system from the condition that caused vision loss, and due to limitations of current technology. However, even with limitations, prosthetic vision may still be able to support functional performance which is sufficient for tasks which are key to restoring independent living and quality of life. Here vision processing can play a key role, ensuring that information which is critical to the performance of key tasks is available within the capability of the available prosthetic vision. In this paper, we frame vision processing for prosthetic vision, highlight some key areas which present problems in terms of quality of life, and present examples where vision processing can help achieve better outcomes.

  16. Low Vision

    Science.gov (United States)

    ... USAJobs Home » Statistics and Data » Low Vision Listen Low Vision Low Vision Defined: Low Vision is defined as the best- ... Ethnicity 2010 U.S. Age-Specific Prevalence Rates for Low Vision by Age, and Race/Ethnicity Table for 2010 ...

  17. Permanent education

    International Nuclear Information System (INIS)

    Gardien, S.; Kirsch, R.

    1998-01-01

    The permanent education of the IPN-Lyon inscribes itself completely in the priorities of the tri-annual plan of education of CNRS. These priorities contribute to evolution of research, evaluation of the professions, integration during the professional carriers of the personnel and form the frame for new management practice implementation

  18. Ablation of whirlin long isoform disrupts the USH2 protein complex and causes vision and hearing loss.

    Directory of Open Access Journals (Sweden)

    Jun Yang

    2010-05-01

    Full Text Available Mutations in whirlin cause either Usher syndrome type II (USH2, a deafness-blindness disorder, or nonsyndromic deafness. The molecular basis for the variable disease expression is unknown. We show here that only the whirlin long isoform, distinct from a short isoform by virtue of having two N-terminal PDZ domains, is expressed in the retina. Both long and short isoforms are expressed in the inner ear. The N-terminal PDZ domains of the long whirlin isoform mediates the formation of a multi-protein complex that includes usherin and VLGR1, both of which are also implicated in USH2. We localized this USH2 protein complex to the periciliary membrane complex (PMC in mouse photoreceptors that appears analogous to the frog periciliary ridge complex. The latter is proposed to play a role in photoreceptor protein trafficking through the connecting cilium. Mice carrying a targeted disruption near the N-terminus of whirlin manifest retinal and inner ear defects, reproducing the clinical features of human USH2 disease. This is in contrast to mice with mutations affecting the C-terminal portion of whirlin in which the phenotype is restricted to the inner ear. In mice lacking any one of the USH2 proteins, the normal localization of all USH2 proteins is disrupted, and there is evidence of protein destabilization. Taken together, our findings provide new insights into the pathogenic mechanism of Usher syndrome. First, the three USH2 proteins exist as an obligatory functional complex in vivo, and loss of one USH2 protein is functionally close to loss of all three. Second, defects in the three USH2 proteins share a common pathogenic process, i.e., disruption of the PMC. Third, whirlin mutations that ablate the N-terminal PDZ domains lead to Usher syndrome, but non-syndromic hearing loss will result if they are spared.

  19. Vision Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Vision Lab personnel perform research, development, testing and evaluation of eye protection and vision performance. The lab maintains and continues to develop...

  20. Controlled delivery of tauroursodeoxycholic acid from biodegradable microspheres slows retinal degeneration and vision loss in P23H rats.

    Directory of Open Access Journals (Sweden)

    Laura Fernández-Sánchez

    Full Text Available Successful drug therapies for treating ocular diseases require effective concentrations of neuroprotective compounds maintained over time at the site of action. The purpose of this work was to assess the efficacy of intravitreal controlled delivery of tauroursodeoxycholic acid (TUDCA encapsulated in poly(D,L-lactic-co-glycolic acid (PLGA microspheres for the treatment of the retina in a rat model of retinitis pigmentosa. PLGA microspheres (MSs containing TUDCA were produced by the O/W emulsion-solvent evaporation technique. Particle size and morphology were assessed by light scattering and scanning electronic microscopy, respectively. Homozygous P23H line 3 rats received a treatment of intravitreal injections of TUDCA-PLGA MSs. Retinal function was assessed by electroretinography at P30, P60, P90 and P120. The density, structure and synaptic contacts of retinal neurons were analyzed using immunofluorescence and confocal microscopy at P90 and P120. TUDCA-loaded PLGA MSs were spherical, with a smooth surface. The production yield was 78%, the MSs mean particle size was 23 μm and the drug loading resulted 12.5 ± 0.8 μg TUDCA/mg MSs. MSs were able to deliver the loaded active compound in a gradual and progressive manner over the 28-day in vitro release study. Scotopic electroretinografic responses showed increased ERG a- and b-wave amplitudes in TUDCA-PLGA-MSs-treated eyes as compared to those injected with unloaded PLGA particles. TUDCA-PLGA-MSs-treated eyes showed more photoreceptor rows than controls. The synaptic contacts of photoreceptors with bipolar and horizontal cells were also preserved in P23H rats treated with TUDCA-PLGA MSs. This work indicates that the slow and continuous delivery of TUDCA from PLGA-MSs has potential neuroprotective effects that could constitute a suitable therapy to prevent neurodegeneration and visual loss in retinitis pigmentosa.

  1. Data on medicinal plants used in Central America to manage diabetes and its sequelae (skin conditions, cardiovascular disease, kidney disease, urinary problems and vision loss

    Directory of Open Access Journals (Sweden)

    Peter Giovannini

    2016-06-01

    Full Text Available The data described in this article is related to the review article “Medicinal plants used in the traditional management of diabetes and its sequelae in Central America: a review” (Giovannini et al., 2016 [1]. We searched publications on the useful plants of Central America in databases and journals by using selected relevant keywords. We then extracted reported uses of medicinal plants within the disease categories: diabetes mellitus, kidney disease, urinary problems, skin diseases and infections, cardiovascular disease, sexual dysfunction, vision loss, and nerve damage. The following countries were included in our definition of Central America: Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica and Panama. Data were compiled in a bespoke Access database. Plant names from the published sources were validated against The Plant List (TPL, (The Plant List, 2013 [2] and accepted names and synonyms were extracted. In total, the database includes 607 plant names obtained from the published sources which correspond to 537 plant taxa, 9271 synonyms and 1055 use reports.

  2. Preliminary Effect of Synthetic Vision Systems Displays to Reduce Low-Visibility Loss of Control and Controlled Flight Into Terrain Accidents

    Science.gov (United States)

    Glaab, Louis J.; Takallu, Mohammad A.

    2002-01-01

    An experimental investigation was conducted to study the effectiveness of Synthetic Vision Systems (SVS) flight displays as a means of eliminating Low Visibility Loss of Control (LVLOC) and Controlled Flight Into Terrain (CFIT) accidents by low time general aviation (GA) pilots. A series of basic maneuvers were performed by 18 subject pilots during transition from Visual Meteorological Conditions (VMC) to Instrument Meteorological Conditions (IMC), with continued flight into IMC, employing a fixed-based flight simulator. A total of three display concepts were employed for this evaluation. One display concept, referred to as the Attitude Indicator (AI) replicated instrumentation common in today's General Aviation (GA) aircraft. The second display concept, referred to as the Electronic Attitude Indicator (EAI), featured an enlarged attitude indicator that was more representative of a glass display that also included advanced flight symbology, such as a velocity vector. The third concept, referred to as the SVS display, was identical to the EAI except that computer-generated terrain imagery replaced the conventional blue-sky/brown-ground of the EAI. Pilot performance parameters, pilot control inputs and physiological data were recorded for post-test analysis. Situation awareness (SA) and qualitative pilot comments were obtained through questionnaires and free-form interviews administered immediately after the experimental session. Initial pilot performance data were obtained by instructor pilot observations. Physiological data (skin temperature, heart rate, and muscle flexure) were also recorded. Preliminary results indicate that far less errors were committed when using the EAI and SVS displays than when using conventional instruments. The specific data example examined in this report illustrates the benefit from SVS displays to avoid massive loss of SA conditions. All pilots acknowledged the enhanced situation awareness provided by the SVS display concept. Levels of

  3. VISION development

    International Nuclear Information System (INIS)

    Hernandez, J.E.; Sherwood, R.J.; Whitman, S.R.

    1994-01-01

    VISION is a flexible and extensible object-oriented programming environment for prototyping computer-vision and pattern-recognition algorithms. This year's effort focused on three major areas: documentation, graphics, and support for new applications

  4. A influência da perda bilateral do primeiro molar inferior permanente na morfologia dentofacial: um estudo cefalométrico The influence of bilateral lower first permanent molar loss on dentofacial morfology: a cephalometric study

    Directory of Open Access Journals (Sweden)

    David Normando

    2010-12-01

    Full Text Available OBJETIVO: avaliar as alterações cefalométricas em pacientes com perda bilateral do primeiro molar inferior permanente. MÉTODOS: foram analisadas 68 telerradiografias laterais de pacientes de consultórios particulares. A amostra foi dividida em dois grupos pareados quanto ao sexo e idade - 34 indivíduos sem perdas (grupo controle e 34 com perda bilateral do primeiro molar inferior permanente (grupo com perda. Foram excluídos da amostra pacientes que haviam perdido outros dentes que não o primeiro molar inferior, casos de agenesia e pacientes com menos de 16 anos de idade. Buscou-se avaliar somente indivíduos que tivessem relatado a perda há pelo menos 5 anos. RESULTADOS: demonstraram que a perda bilateral do primeiro molar inferior permanente leva ao suave fechamento do ângulo GnSN (P=0,05, um giro anti-horário do plano oclusal (P=0,0001, uma suave diminuição da altura facial anteroinferior (P=0,05, uma acentuada inclinação lingual (P=0,04 e retrusão dos incisivos inferiores (P=0,03. Por outro lado, a perda bilateral do primeiro molar inferior permanente não foi capaz de influenciar a relação maxilomandibular no sentido anteroposterior (P=0,21, a quantidade de mento (P=0,45, a inclinação dos incisivos superiores (P=0,12 e a posição anteroposterior dos incisivos superiores (P=0,46. CONCLUSÃO: a perda bilateral dos primeiros molares inferiores é capaz de produzir alterações marcantes no posicionamento dos incisivos inferiores e no plano oclusal, além de uma suave redução vertical da faceOBJECTIVE: To evaluate cephalometric changes in patients after bilateral loss of lower first permanent molar teeth. METHODS: Sixty-eight lateral radiographs of patients from private practices were analyzed. The sample was divided into two groups matched for age and gender: 34 individuals without loss (control group and 34 presenting with bilateral loss of lower first permanent molar teeth (loss group. Patients who had lost teeth other

  5. Computational vision

    CERN Document Server

    Wechsler, Harry

    1990-01-01

    The book is suitable for advanced courses in computer vision and image processing. In addition to providing an overall view of computational vision, it contains extensive material on topics that are not usually covered in computer vision texts (including parallel distributed processing and neural networks) and considers many real applications.

  6. Trends in the prevalence of autism spectrum disorder, cerebral palsy, hearing loss, intellectual disability, and vision impairment, metropolitan atlanta, 1991-2010.

    Directory of Open Access Journals (Sweden)

    Kim Van Naarden Braun

    Full Text Available This study examined the prevalence and characteristics of autism spectrum disorder (ASD, cerebral palsy (CP, hearing loss (HL, intellectual disability (ID, and vision impairment (VI over a 15-20 year time period, with specific focus on concurrent changes in ASD and ID prevalence. We used data from a population-based developmental disabilities surveillance program for 8-year-olds in metropolitan Atlanta. From 1991-2010, prevalence estimates of ID and HL were stable with slight increases in VI prevalence. CP prevalence was constant from 1993-2010. The average annual increase in ASD prevalence was 9.3% per year from 1996-2010, with a 269% increase from 4.2 per 1,000 in 1996 to 15.5 per 1,000 in 2010. From 2000-2010, the prevalence of ID without ASD was stable; during the same time, the prevalence of ASD with and without co-occurring ID increased by an average of 6.6% and 9.6% per year, respectively. ASD prevalence increases were found among both males and females, and among nearly all racial/ethnic subgroups and levels of intellectual ability. Average annual prevalence estimates from 1991-2010 underscore the significant community resources needed to provide early intervention and ongoing supports for children with ID (13.0 per 1,000, CP, (3.5 per 1,000, HL (1.4 per 1,000 and VI (1.3 in 1,000, with a growing urgency for children with ASD.

  7. Analysis of Vision Loss Caused by Radiation-Induced Optic Neuropathy After Particle Therapy for Head-and-Neck and Skull-Base Tumors Adjacent to Optic Nerves

    International Nuclear Information System (INIS)

    Demizu, Yusuke; Murakami, Masao; Miyawaki, Daisuke; Niwa, Yasue; Akagi, Takashi; Sasaki, Ryohei; Terashima, Kazuki; Suga, Daisaku; Kamae, Isao; Hishikawa, Yoshio

    2009-01-01

    Purpose: To assess the incident rates of vision loss (VL; based on counting fingers or more severe) caused by radiation-induced optic neuropathy (RION) after particle therapy for tumors adjacent to optic nerves (ONs), and to evaluate factors that may contribute to VL. Methods and Materials: From August 2001 to August 2006, 104 patients with head-and-neck or skull-base tumors adjacent to ONs were treated with carbon ion or proton radiotherapy. Among them, 145 ONs of 75 patients were irradiated and followed for greater than 12 months. The incident rate of VL and the prognostic factors for occurrence of VL were evaluated. The late effects of carbon ion and proton beams were compared on the basis of a biologically effective dose at α/β = 3 gray equivalent (GyE 3 ). Results: Eight patients (11%) experienced VL resulting from RION. The onset of VL ranged from 17 to 58 months. The median follow-up was 25 months. No significant difference was observed between the carbon ion and proton beam treatment groups. On univariate analysis, age (>60 years), diabetes mellitus, and maximum dose to the ON (>110 GyE 3 ) were significant, whereas on multivariate analysis only diabetes mellitus was found to be significant for VL. Conclusions: The time to the onset of VL was highly variable. There was no statistically significant difference between carbon ion and proton beam treatments over the follow-up period. Based on multivariate analysis, diabetes mellitus correlated with the occurrence of VL. A larger study with longer follow-up is warranted.

  8. Pigment epithelial detachment followed by retinal cystoid degeneration leads to vision loss in treatment of neovascular age-related macular degeneration.

    Science.gov (United States)

    Schmidt-Erfurth, Ursula; Waldstein, Sebastian M; Deak, Gabor-Gyoergy; Kundi, Michael; Simader, Christian

    2015-04-01

    AMD is strongly determined by morphologic features. The subretinal pigment epithelium lesion underlying PED appears to be the primary indicator for progressive disease activity, whereas secondary cystoid degeneration is the most relevant imaging marker for visual function. Clinically, PED emerged as trigger for consecutive vision loss in PRN treatment. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  9. Development and evaluation of vision rehabilitation devices.

    Science.gov (United States)

    Luo, Gang; Peli, Eli

    2011-01-01

    We have developed a range of vision rehabilitation devices and techniques for people with impaired vision due to either central vision loss or severely restricted peripheral visual field. We have conducted evaluation studies with patients to test the utilities of these techniques in an effort to document their advantages as well as their limitations. Here we describe our work on a visual field expander based on a head mounted display (HMD) for tunnel vision, a vision enhancement device for central vision loss, and a frequency domain JPEG/MPEG based image enhancement technique. All the evaluation studies included visual search paradigms that are suitable for conducting indoor controllable experiments.

  10. Low Vision Care: The Need to Maximise Visual Potential

    Directory of Open Access Journals (Sweden)

    Ramachandra Pararajasegaram

    2004-01-01

    Full Text Available People with low vision have residual vision with some light perception, but their vision loss does not lend itself to improvement by standard spectacles or medical or surgical treatment. Such persons have the potential for enhanced functional vision if they receive appropriate low vision care services.

  11. Essure Permanent Birth Control

    Science.gov (United States)

    ... Prosthetics Essure Permanent Birth Control Essure Permanent Birth Control Share Tweet Linkedin Pin it More sharing options ... Print Essure is a a permanently implanted birth control device for women (female sterilization). Implantation of Essure ...

  12. Low Vision Rehabilitation and Diabetic Retinopathy

    International Nuclear Information System (INIS)

    Khan, Sarfaraz A.

    2007-01-01

    Diabetic retinopathy is emerging as a major cause of blindness. Diabetic retinopathy calls for a multidisciplinary to the patients. Management of the patient requires a team work by the internist, diabetologist, dietician, ophthalmologist and low vision therapist. Diabetic retinopathy very often results in vision loss. It is important for ophthalmologist to recognize the importance of low vision rehabilitation in formulating appropriate treatment strategies. People with low vision loss due to diabetic retinopathy usually experience difficulty in daily life. Most people with diabetic retinopathy (who have remaining useful vision) can be helped with low vision devices. However, often one low vision device may not be suitable for all purposes. A comprehensive low vision evaluation is required to assess the person's current visual status, identify the goals and the visual needs, and then design an individualized vision rehabilitation program to meet these needs. (author)

  13. Barriers to accessing low vision services.

    Science.gov (United States)

    Pollard, Tamara L; Simpson, John A; Lamoureux, Ecosse L; Keeffe, Jill E

    2003-07-01

    To investigate barriers to accessing low vision services in Australia. Adults with a vision impairment (vision difficulties, duration of vision loss and satisfaction with vision and also examined issues of awareness of low vision services and referral to services. Focus groups were also conducted with vision impaired (Vision Australia Foundation. The discussions were recorded and transcribed. The questionnaire revealed that referral to low vision services was associated with a greater degree of vision loss (p = 0.002) and a greater self-perception of low vision (p = 0.005) but that referral was not associated with satisfaction (p = 0.144) or difficulties related to vision (p = 0.169). Participants with mild and moderate vision impairment each reported similar levels of difficulties with daily activities and satisfaction with their vision (p > 0.05). However, there was a significant difference in the level of difficulties experienced with daily activities between those with mild-moderate and severe vision impairment (p low vision services related to awareness of services among the general public and eye care professionals, understanding of low vision and the services available, acceptance of low vision, the referral process, and transport. In addition to the expected difficulties with lack of awareness of services by people with low vision, many people do not understand what the services provide and do not identify themselves as having low vision. Knowledge of these barriers, from the perspective of people with low vision, can now be used to guide the development and content of future health-promotion campaigns.

  14. Vision Screening in Children Aged 6 Months to 5 Years: US Preventive Services Task Force Recommendation Statement.

    Science.gov (United States)

    Grossman, David C; Curry, Susan J; Owens, Douglas K; Barry, Michael J; Davidson, Karina W; Doubeni, Chyke A; Epling, John W; Kemper, Alex R; Krist, Alex H; Kurth, Ann E; Landefeld, C Seth; Mangione, Carol M; Phipps, Maureen G; Silverstein, Michael; Simon, Melissa A; Tseng, Chien-Wen

    2017-09-05

    One of the most important causes of vision abnormalities in children is amblyopia (also known as "lazy eye"). Amblyopia is an alteration in the visual neural pathway in a child's developing brain that can lead to permanent vision loss in the affected eye. Among children younger than 6 years, 1% to 6% have amblyopia or its risk factors (strabismus, anisometropia, or both). Early identification of vision abnormalities could prevent the development of amblyopia. Studies show that screening rates among children vary by race/ethnicity and family income. Data based on parent reports from 2009-2010 indicated identical screening rates among black non-Hispanic children and white non-Hispanic children (80.7%); however, Hispanic children were less likely than non-Hispanic children to report vision screening (69.8%). Children whose families earned 200% or more above the federal poverty level were more likely to report vision screening than families with lower incomes. To update the 2011 US Preventive Services Task Force (USPSTF) recommendation on screening for amblyopia and its risk factors in children. The USPSTF reviewed the evidence on the accuracy of vision screening tests and the benefits and harms of vision screening and treatment. Surgical interventions were considered to be out of scope for this review. Treatment of amblyopia is associated with moderate improvements in visual acuity in children aged 3 to 5 years, which are likely to result in permanent improvements in vision throughout life. The USPSTF concluded that the benefits are moderate because untreated amblyopia results in permanent, uncorrectable vision loss, and the benefits of screening and treatment potentially can be experienced over a child's lifetime. The USPSTF found adequate evidence to bound the potential harms of treatment (ie, higher false-positive rates in low-prevalence populations) as small. Therefore, the USPSTF concluded with moderate certainty that the overall net benefit is moderate for

  15. Asexual reproduction induces a rapid and permanent loss of sexual reproduction capacity in the rice fungal pathogen Magnaporthe oryzae: results of in vitro experimental evolution assays

    Directory of Open Access Journals (Sweden)

    Saleh Dounia

    2012-03-01

    Full Text Available Abstract Background Sexual reproduction is common in eukaryotic microorganisms, with few species reproducing exclusively asexually. However, in some organisms, such as fungi, asexual reproduction alternates with episodic sexual reproduction events. Fungi are thus appropriate organisms for studies of the reasons for the selection of sexuality or clonality and of the mechanisms underlying this selection. Magnaporthe oryzae, an Ascomycete causing blast disease on rice, reproduces mostly asexually in natura. Sexual reproduction is possible in vitro and requires (i two strains of opposite mating types including (ii at least one female-fertile strain (i.e. a strain able to produce perithecia, the female organs in which meiosis occurs. Female-fertile strains are found only in limited areas of Asia, in which evidence for contemporary recombination has recently been obtained. We induced the forced evolution of four Chinese female-fertile strains in vitro by the weekly transfer of asexual spores (conidia between Petri dishes. We aimed to determine whether female fertility was rapidly lost in the absence of sexual reproduction and whether this loss was controlled genetically or epigenetically. Results All the strains became female-sterile after 10 to 19 rounds of selection under asexual conditions. As no single-spore isolation was carried out, the observed decrease in the production of perithecia reflected the emergence and the invasion of female-sterile mutants. The female-sterile phenotype segregated in the offspring of crosses between female-sterile evolved strains and female-fertile wild-type strains. This segregation was maintained in the second generation in backcrosses. Female-sterile evolved strains were subjected to several stresses, but none induced the restoration of female fertility. This loss of fertility was therefore probably due to genetic rather than epigenetic mechanisms. In competition experiments, female-sterile mutants produced similar

  16. Micro Vision

    OpenAIRE

    Ohba, Kohtaro; Ohara, Kenichi

    2007-01-01

    In the field of the micro vision, there are few researches compared with macro environment. However, applying to the study result for macro computer vision technique, you can measure and observe the micro environment. Moreover, based on the effects of micro environment, it is possible to discovery the new theories and new techniques.

  17. Vision in water.

    Science.gov (United States)

    Atchison, David A; Valentine, Emma L; Gibson, Georgina; Thomas, Hannah R; Oh, Sera; Pyo, Young Ah; Lacherez, Philippe; Mathur, Ankit

    2013-09-06

    The purpose of this study is to determine visual performance in water, including the influence of pupil size. The water environment was simulated by placing goggles filled with saline in front of the eyes with apertures placed at the front of the goggles. Correction factors were determined for the different magnification under this condition in order to estimate vision in water. Experiments were conducted on letter visual acuity (seven participants), grating resolution (eight participants), and grating contrast sensitivity (one participant). For letter acuity, mean loss of vision in water, compared to corrected vision in air, varied between 1.1 log min of arc resolution (logMAR) for a 1 mm aperture to 2.2 logMAR for a 7 mm aperture. The vision in min of arc was described well by a linear relationship with pupil size. For grating acuity, mean loss varied between 1.1 logMAR for a 2 mm aperture to 1.2 logMAR for a 6 mm aperture. Contrast sensitivity for a 2 mm aperture deteriorated as spatial frequency increased with a 2 log unit loss by 3 c/°. Superimposed on this deterioration were depressions (notches) in sensitivity with the first three notches occurring at 0.45, 0.8, and 1.3 c/° with estimates for water of 0.39, 0.70, and 1.13 c/°. In conclusion, vision in water is poor. It becomes worse as pupil size increases, but the effects are much more marked for letter targets than for grating targets.

  18. Marxism as permanent revolution

    NARCIS (Netherlands)

    van Ree, E.

    2013-01-01

    This article argues that the 'permanent revolution' represented the dominant element in Karl Marx and Friedrich Engels' political discourse, and that it tended to overrule considerations encapsulated in 'historical materialism'. In Marx and Engels's understanding, permanent revolution did not

  19. Industrial vision

    DEFF Research Database (Denmark)

    Knudsen, Ole

    1998-01-01

    This dissertation is concerned with the introduction of vision-based application s in the ship building industry. The industrial research project is divided into a natural seq uence of developments, from basic theoretical projective image generation via CAD and subpixel analysis to a description...... is present ed, and the variability of the parameters is examined and described. The concept of using CAD together with vision information is based on the fact that all items processed at OSS have an associated complete 3D CAD model that is accessible at all production states. This concept gives numerous...... possibilities for using vision in applications which otherwise would be very difficult to automate. The requirement for low tolerances in production is, despite the huge dimensions of the items involved, extreme. This fact makes great demands on the ability to do robust sub pixel estimation. A new method based...

  20. Disruption of ion-trafficking system in the cochlear spiral ligament prior to permanent hearing loss induced by exposure to intense noise: possible involvement of 4-hydroxy-2-nonenal as a mediator of oxidative stress.

    Directory of Open Access Journals (Sweden)

    Taro Yamaguchi

    Full Text Available Noise-induced hearing loss is at least in part due to disruption of endocochlear potential, which is maintained by various K(+ transport apparatuses including Na(+, K(+-ATPase and gap junction-mediated intercellular communication in the lateral wall structures. In this study, we examined the changes in the ion-trafficking-related proteins in the spiral ligament fibrocytes (SLFs following in vivo acoustic overstimulation or in vitro exposure of cultured SLFs to 4-hydroxy-2-nonenal, which is a mediator of oxidative stress. Connexin (Cx26 and Cx30 were ubiquitously expressed throughout the spiral ligament, whereas Na(+, K(+-ATPase α1 was predominantly detected in the stria vascularis and spiral prominence (type 2 SLFs. One-hour exposure of mice to 8 kHz octave band noise at a 110 dB sound pressure level produced an immediate and prolonged decrease in the Cx26 expression level and in Na+, K(+-ATPase activity, as well as a delayed decrease in Cx30 expression in the SLFs. The noise-induced hearing loss and decrease in the Cx26 protein level and Na(+, K(+-ATPase activity were abolished by a systemic treatment with a free radical-scavenging agent, 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl, or with a nitric oxide synthase inhibitor, N(ω-nitro-L-arginine methyl ester hydrochloride. In vitro exposure of SLFs in primary culture to 4-hydroxy-2-nonenal produced a decrease in the protein levels of Cx26 and Na(+, K(+-ATPase α1, as well as Na(+, K(+-ATPase activity, and also resulted in dysfunction of the intercellular communication between the SLFs. Taken together, our data suggest that disruption of the ion-trafficking system in the cochlear SLFs is caused by the decrease in Cxs level and Na(+, K(+-ATPase activity, and at least in part involved in permanent hearing loss induced by intense noise. Oxidative stress-mediated products might contribute to the decrease in Cxs content and Na(+, K(+-ATPase activity in the cochlear lateral wall structures.

  1. Agrarian Visions.

    Science.gov (United States)

    Theobald, Paul

    A new feature in "Country Teacher,""Agrarian Visions" reminds rural teachers that they can do something about rural decline. Like to populism of the 1890s, the "new populism" advocates rural living. Current attempts to address rural decline are contrary to agrarianism because: (1) telecommunications experts seek to…

  2. Fractured Visions

    DEFF Research Database (Denmark)

    Bonde, Inger Ellekilde

    2016-01-01

    In the post-war period a heterogeneous group of photographers articulate a new photographic approach to the city as motive in a photographic language that combines intense formalism with subjective vision. This paper analyses the photobook Fragments of a City published in 1960 by Danish photograp...

  3. Embodied Visions

    DEFF Research Database (Denmark)

    Grodal, Torben Kragh

    Embodied Visions presents a groundbreaking analysis of film through the lens of bioculturalism, revealing how human biology as well as human culture determine how films are made and experienced. Throughout the book the author uses the breakthroughs of modern brain science to explain general featu...

  4. Vision Screening

    Science.gov (United States)

    ... an efficient and cost-effective method to identify children with visual impairment or eye conditions that are likely to lead ... main goal of vision screening is to identify children who have or are at ... visual impairment unless treated in early childhood. Other problems that ...

  5. 78 FR 63302 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2013-10-23

    .... Ferris Mr. Ferris, 70, has had complete loss of vision in his right eye since 1991. The visual acuity in... sufficient vision to perform his driving tasks to operate a commercial vehicle.'' Mr. Ferris reported that he...

  6. The permanent process

    DEFF Research Database (Denmark)

    Møller, Jesper; McCullagh, Peter

    We extend the boson process first to a large class of Cox processes and second an even larger class of infinitely divisible point processes. Density and moment results are studied in detail. These results are obtained in closed form as weighted permanents, so the extension is called a permanent...... process. Temporal extensions and a particularly tractable case of the permanent process are also studied. Extensions of the ferminon process along similar lines, leading to so-called determinant processes, are discussed at the end. While the permanent process is attractive, the determinant process...

  7. Visions and visioning in foresight activities

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Grosu, Dan

    2007-01-01

    The paper discusses the roles of visioning processes and visions in foresight activities and in societal discourses and changes parallel to or following foresight activities. The overall topic can be characterised as the dynamics and mechanisms that make visions and visioning processes work...... or not work. The theoretical part of the paper presents an actor-network theory approach to the analyses of visions and visioning processes, where the shaping of the visions and the visioning and what has made them work or not work is analysed. The empirical part is based on analyses of the roles of visions...... and visioning processes in a number of foresight processes from different societal contexts. The analyses have been carried out as part of the work in the COST A22 network on foresight. A vision is here understood as a description of a desirable or preferable future, compared to a scenario which is understood...

  8. Pleiades Visions

    Science.gov (United States)

    Whitehouse, M.

    2016-01-01

    Pleiades Visions (2012) is my new musical composition for organ that takes inspiration from traditional lore and music associated with the Pleiades (Seven Sisters) star cluster from Australian Aboriginal, Native American, and Native Hawaiian cultures. It is based on my doctoral dissertation research incorporating techniques from the fields of ethnomusicology and cultural astronomy; this research likely represents a new area of inquiry for both fields. This large-scale work employs the organ's vast sonic resources to evoke the majesty of the night sky and the expansive landscapes of the homelands of the above-mentioned peoples. Other important themes in Pleiades Visions are those of place, origins, cosmology, and the creation of the world.

  9. Optoelectronic vision

    Science.gov (United States)

    Ren, Chunye; Parel, Jean-Marie A.

    1993-06-01

    Scientists have searched every discipline to find effective methods of treating blindness, such as using aids based on conversion of the optical image, to auditory or tactile stimuli. However, the limited performance of such equipment and difficulties in training patients have seriously hampered practical applications. A great edification has been given by the discovery of Foerster (1929) and Krause & Schum (1931), who found that the electrical stimulation of the visual cortex evokes the perception of a small spot of light called `phosphene' in both blind and sighted subjects. According to this principle, it is possible to invite artificial vision by using stimulation with electrodes placed on the vision neural system, thereby developing a prosthesis for the blind that might be of value in reading and mobility. In fact, a number of investigators have already exploited this phenomena to produce a functional visual prosthesis, bringing about great advances in this area.

  10. Lambda Vision

    Science.gov (United States)

    Czajkowski, Michael

    2014-06-01

    There is an explosion in the quantity and quality of IMINT data being captured in Intelligence Surveillance and Reconnaissance (ISR) today. While automated exploitation techniques involving computer vision are arriving, only a few architectures can manage both the storage and bandwidth of large volumes of IMINT data and also present results to analysts quickly. Lockheed Martin Advanced Technology Laboratories (ATL) has been actively researching in the area of applying Big Data cloud computing techniques to computer vision applications. This paper presents the results of this work in adopting a Lambda Architecture to process and disseminate IMINT data using computer vision algorithms. The approach embodies an end-to-end solution by processing IMINT data from sensors to serving information products quickly to analysts, independent of the size of the data. The solution lies in dividing up the architecture into a speed layer for low-latent processing and a batch layer for higher quality answers at the expense of time, but in a robust and fault-tolerant way. This approach was evaluated using a large corpus of IMINT data collected by a C-130 Shadow Harvest sensor over Afghanistan from 2010 through 2012. The evaluation data corpus included full motion video from both narrow and wide area field-of-views. The evaluation was done on a scaled-out cloud infrastructure that is similar in composition to those found in the Intelligence Community. The paper shows experimental results to prove the scalability of the architecture and precision of its results using a computer vision algorithm designed to identify man-made objects in sparse data terrain.

  11. Virtual Vision

    Science.gov (United States)

    Terzopoulos, Demetri; Qureshi, Faisal Z.

    Computer vision and sensor networks researchers are increasingly motivated to investigate complex multi-camera sensing and control issues that arise in the automatic visual surveillance of extensive, highly populated public spaces such as airports and train stations. However, they often encounter serious impediments to deploying and experimenting with large-scale physical camera networks in such real-world environments. We propose an alternative approach called "Virtual Vision", which facilitates this type of research through the virtual reality simulation of populated urban spaces, camera sensor networks, and computer vision on commodity computers. We demonstrate the usefulness of our approach by developing two highly automated surveillance systems comprising passive and active pan/tilt/zoom cameras that are deployed in a virtual train station environment populated by autonomous, lifelike virtual pedestrians. The easily reconfigurable virtual cameras distributed in this environment generate synthetic video feeds that emulate those acquired by real surveillance cameras monitoring public spaces. The novel multi-camera control strategies that we describe enable the cameras to collaborate in persistently observing pedestrians of interest and in acquiring close-up videos of pedestrians in designated areas.

  12. Functional Vision Observation. Technical Assistance Paper.

    Science.gov (United States)

    Florida State Dept. of Education, Tallahassee. Bureau of Education for Exceptional Students.

    Technical assistance is provided concerning documentation of functional vision loss for Florida students with visual impairments. The functional vision observation should obtain enough information for determination of special service eligibility. The observation is designed to supplement information on the medical eye examination, and is conducted…

  13. Nonuniform radiation damage in permanent magnet quadrupoles.

    Science.gov (United States)

    Danly, C R; Merrill, F E; Barlow, D; Mariam, F G

    2014-08-01

    We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL's pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components.

  14. Nonuniform radiation damage in permanent magnet quadrupoles

    International Nuclear Information System (INIS)

    Danly, C. R.; Merrill, F. E.; Barlow, D.; Mariam, F. G.

    2014-01-01

    We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL’s pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components

  15. Nonuniform radiation damage in permanent magnet quadrupoles

    Energy Technology Data Exchange (ETDEWEB)

    Danly, C. R.; Merrill, F. E.; Barlow, D.; Mariam, F. G. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

    2014-08-15

    We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL’s pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components.

  16. Evolution of Vision

    Science.gov (United States)

    Ostrovsky, Mikhail

    The evolution of photoreception, giving rise to eye, offers a kaleidoscopic view on selection acting at both the organ and molecular levels. The molecular level is mainly considered in the lecture. The greatest progress to date has been made in relation to the opsin visual pigments. Opsins appeared before eyes did. Two- and three-dimensional organization for rhodopsin in the rod outer segment disk membrane, as well as molecular mechanisms of visual pigments spectral tuning, photoisomerization and also opsin as a G-protein coupled receptor are considered. Molecular mechanisms of visual pigments spectral tuning, namely switching of chromophore (physiological time scale) and amino acid changes in the chromophore site of opsin (evolutionary time scale) is considered in the lecture. Photoisomerization of rhodopsin chromophore, 11-cis retinal is the only photochemical reaction in vision. The reaction is extemely fast (less that 200 fs) and high efficient (. is 0.65). The rhodopsin photolysis and kinetics of the earlier products appearance, photo- and bathorhodopsin, is considered. It is known that light is not only a carrier of information, but also a risk factor of damage to the eye. This photobiological paradox of vision is mainly due to the nature of rhodopsin chromophore. Photooxidation is the base of the paradox. All factors present in the phototrceptor cells to initiate free-radical photooxidation: photosensitizers, oxygen and substrates of oxidation: lipids and proteins (opsin). That is why photoprotective system of the eye structures appeared in the course of evolution. Three lines of protective system to prevent light damage to the retina and retina pigment epithelium is known: permanent renewal of rod and cone outer segment, powerful antioxidant system and optical media as cut-off filters where the lens is a key component. The molecular mechanisms of light damage to the eye and photoprotective system of the eye is considered in the lecture. The molecular

  17. Low Vision FAQs

    Science.gov (United States)

    ... de los Ojos Cómo hablarle a su oculista Low Vision FAQs What is low vision? Low vision is a visual impairment, not correctable ... person’s ability to perform everyday activities. What causes low vision? Low vision can result from a variety of ...

  18. Permanences GAG-EPA

    CERN Document Server

    GAC-EPA

    2015-01-01

    Le GAC organise chaque mois des permanences avec entretiens individuels. La prochaine permanence se tiendra le : Mardi 5 mai de 13 h 30 à 16 h 00 Salle de réunion de l’Association du personnel Les permanences suivantes auront lieu les mardis 2 juin, 1er septembre, 6 octobre, 3 novembre et 1er décembre 2015. Les permanences du Groupement des Anciens sont ouvertes aux bénéficiaires de la Caisse de pensions (y compris les conjoints survivants) et à tous ceux qui approchent de la retraite. Nous invitons vivement ces derniers à s’associer à notre groupement en se procurant, auprès de l’Association du personnel, les documents nécessaires.

  19. Permanent quadrupole magnets

    International Nuclear Information System (INIS)

    Bush, E.D. Jr.

    1976-01-01

    A family of quadrupole magnets using a soft iron return yoke and circular cross-section permanent magnet poles were fabricated to investigate the feasibility for use in ion or electron beam focusing applications in accelerators and transport lines. Magnetic field measurements yielded promising results. In fixed-field applications, permanent magnets with sufficient gradients would be a low cost substitute for conventional electromagnets, eliminating the need for power supplies, associated wiring, and cooling. Based on preliminary tests, it was seen that permanent quadrupole magnets can offer a low cost, reliable solution in applications requiring small, fixed-field focusing devices for use in ion or electron-beam transport systems. Permanent magnets do require special considerations in design, fabrication, handling, and service that are different than encountered in conventional quadrupole magnets. If these basic conditions are satisfied, the resulting beam-focusing device would be stable, maintenance free, with virtually an indefinite lifetime

  20. Permanent quadrupole magnets

    International Nuclear Information System (INIS)

    Bush, E.D. Jr.

    1976-01-01

    A family of quadrupole magnets using a soft iron return yoke and circular cross-section permanent magnet poles were fabricated to investigate the feasibility for use in ion or electron beam focusing applications in accelerators and transport lines. Magnetic field measurements yielded promising results. In fixed-field applications, permanent magnets with sufficient gradients would be a low cost substitute for conventional electromagnets, eliminating the need for power supplies, associated wiring, and cooling. (author)

  1. Marxism as permanent revolution

    OpenAIRE

    van Ree, E.

    2013-01-01

    This article argues that the 'permanent revolution' represented the dominant element in Karl Marx and Friedrich Engels' political discourse, and that it tended to overrule considerations encapsulated in 'historical materialism'. In Marx and Engels's understanding, permanent revolution did not represent a historical shortcut under exceptional circumstances, but the course revolutions in the modern era would normally take. Marx and Engels traced back the pattern to the sixteenth century. It is ...

  2. Design of permanent magnet synchronous motor within minimum cost

    OpenAIRE

    Півняк, Геннадій Григорович; Бешта, Олександр Степанович; Фурса, Сергій Григорійович; Neuberger, Nikolaus; Nolle, N.

    2010-01-01

    The article describes design and simulation experience of permanent magnet synchronous motor (PMSM). The design goal is to develop PMSM of the least possible cost. For that purpose the standard induction motor stator was applied as a basic solution and permanent magnets were installed in rotor. Simulation results are presented, the dependence of efficiency and total loss on magnet material mass are obtained. The optimal value of permanent magnets is estimated for the given electric motor frame.

  3. Vision Screening

    Science.gov (United States)

    1993-01-01

    The Visi Screen OSS-C, marketed by Vision Research Corporation, incorporates image processing technology originally developed by Marshall Space Flight Center. Its advantage in eye screening is speed. Because it requires no response from a subject, it can be used to detect eye problems in very young children. An electronic flash from a 35 millimeter camera sends light into a child's eyes, which is reflected back to the camera lens. The photorefractor then analyzes the retinal reflexes generated and produces an image of the child's eyes, which enables a trained observer to identify any defects. The device is used by pediatricians, day care centers and civic organizations that concentrate on children with special needs.

  4. Robot vision

    International Nuclear Information System (INIS)

    Hall, E.L.

    1984-01-01

    Almost all industrial robots use internal sensors such as shaft encoders which measure rotary position, or tachometers which measure velocity, to control their motions. Most controllers also provide interface capabilities so that signals from conveyors, machine tools, and the robot itself may be used to accomplish a task. However, advanced external sensors, such as visual sensors, can provide a much greater degree of adaptability for robot control as well as add automatic inspection capabilities to the industrial robot. Visual and other sensors are now being used in fundamental operations such as material processing with immediate inspection, material handling with adaption, arc welding, and complex assembly tasks. A new industry of robot vision has emerged. The application of these systems is an area of great potential

  5. Assessment and Instruction of Object Permanence in Children with Blindness and Multiple Disabilities

    Science.gov (United States)

    Bruce, Susan M.; Vargas, Claudia

    2012-01-01

    Introduction: This article discusses the impact of blindness and low vision on the development of object permanence and provides suggestions for assessment and instruction. Methods: The reviewed literature was identified by searching both ERIC and Psych Info using combinations of search terms such as "object permanence" and "visual…

  6. Family Functioning and Low Vision: A Systematic Review

    Science.gov (United States)

    Bambara, Jennifer K.; Wadley, Virginia; Owsley, Cynthia; Martin, Roy C.; Porter, Chebon; Dreer, Laura E.

    2009-01-01

    This review highlights the literature on the function and adjustment process of family members of persons with adult-onset vision loss. The majority of the literature has focused on the unique role that the family plays in providing both instrumental and emotional support to adults with low vision. In contrast, the impact of low vision on the…

  7. Color vision test

    Science.gov (United States)

    ... present from birth) color vision problems: Achromatopsia -- complete color blindness , seeing only shades of gray Deuteranopia -- difficulty telling ... Vision test - color; Ishihara color vision test Images Color blindness tests References Bowling B. Hereditary fundus dystrophies. In: ...

  8. Treatment of ectopic first permanent molar teeth.

    LENUS (Irish Health Repository)

    Hennessy, Joe

    2012-11-01

    Ectopic eruption of the first permanent molar is a relatively common occurence in the developing dentition. A range of treatment options are available to the clinician provided that diagnosis is made early. Non-treatment can result in premature exfoliation of the second primary molar, space loss and impaction of the second premolar. This paper will describe the management of ectopic first permanent molars, using clinical examples to illustrate the available treatment options. CLINICAL RELEVANCE: This paper is relevant to every general dental practitioner who treats patients in mixed dentition.

  9. Treatment of ectopic first permanent molar teeth.

    Science.gov (United States)

    Hennessy, Joe; Al-Awadhi, E A; Dwyer, Lian O; Leith, Rona

    2012-11-01

    Ectopic eruption of the first permanent molar is a relatively common occurence in the developing dentition. A range of treatment options are available to the clinician provided that diagnosis is made early. Non-treatment can result in premature exfoliation of the second primary molar, space loss and impaction of the second premolar. This paper will describe the management of ectopic first permanent molars, using clinical examples to illustrate the available treatment options. This paper is relevant to every general dental practitioner who treats patients in mixed dentition.

  10. Introduction to permanent magnets

    International Nuclear Information System (INIS)

    Zijlstra, H.

    1985-01-01

    Some general considerations concerning the application of permanent magnets are developed. The relevant magnet properties are discussed, with particular reference to Nd-Fe-B alloy. The author comes to the following conclusions; the air gap field B should be high, for high electrical efficiency; the magnet should face the air gap, for efficient use of the magnet material; the magnet material should therefore have a high remanence; and the new Nd-Fe-B magnet fits in nicely, having (potentially) the highest remanence ever reported in permanent magnets, combined with sufficient coercivity to sustain it

  11. Object permanence in lemurs.

    Science.gov (United States)

    Deppe, Anja M; Wright, Patricia C; Szelistowski, William A

    2009-03-01

    Object permanence, the ability to mentally represent objects that have disappeared from view, should be advantageous to animals in their interaction with the natural world. The objective of this study was to examine whether lemurs possess object permanence. Thirteen adult subjects representing four species of diurnal lemur (Eulemur fulvus rufus, Eulemur mongoz, Lemur catta and Hapalemur griseus) were presented with seven standard Piagetian visible and invisible object displacement tests, plus one single visible test where the subject had to wait predetermined times before allowed to search, and two invisible tests where each hiding place was made visually unique. In all visible tests lemurs were able to find an object that had been in clear view before being hidden. However, when lemurs were not allowed to search for up to 25-s, performance declined with increasing time-delay. Subjects did not outperform chance on any invisible displacements regardless of whether hiding places were visually uniform or unique, therefore the upper limit of object permanence observed was Stage 5b. Lemur species in this study eat stationary foods and are not subject to stalking predators, thus Stage 5 object permanence is probably sufficient to solve most problems encountered in the wild.

  12. Loss of vision: imaging the visual pathways

    International Nuclear Information System (INIS)

    Jaeger, H.R.

    2005-01-01

    This is an overview of diseases presenting with visual impairment, which aims to provide an understanding of the anatomy and pathology of the visual pathways. It discusses the relevant clinical background and neuroimaging findings on CT and standard and advanced MRI of diseases affecting the globe; optic nerve/sheath complex; optic chiasm, tract and radiation; and visual cortex. The overview covers common tumours, trauma, inflammatory and vascular pathology, and conditions such as benign intracranial hypertension and posterior reversible leukoencephalopathy syndrome. (orig.)

  13. The Question of Decalage Between Object Permanence and Person Permanence

    Science.gov (United States)

    And Others; Jackson, Elaine

    1978-01-01

    Presents a study of decalage between object permanence and person permanence. Decalage was influenced by environmental as well as stimulus factors with infants tested between 6- and 81/4-months/of-age. (BD)

  14. Variable Permanent Magnet Quadrupole

    International Nuclear Information System (INIS)

    Mihara, T.; Iwashita, Y.; Kyoto U.; Kumada, M.; NIRS, Chiba; Spencer, C.M.; SLAC

    2007-01-01

    A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments

  15. Superconducting permanent magnets

    International Nuclear Information System (INIS)

    Wipf, S.L.; Laquer, H.L.

    1989-01-01

    The concept of superconducting permanent magnets with fields trapped in shells or cylinders of Type II superconductors is an old one. Unfortunately, the low values of 0.5 to 1T for the first flux jump field, which is independent of the actual current density, have frustrated its implementation with classical Type II superconductors. The fact that the flux jump fields for high temperature superconductors should be an order of magnitude larger at liquid nitrogen temperatures allows us to reconsider these options. Analysis of the hysteresis patterns, based on the critical state model, shows that, if the dimensions are chosen so that the sample is penetrated at a field B/sub p/, which is equal to or just less than the first flux jump field, B/sub fj/, a temporarily applied field of 2B/sub fj/ will trap 0.5 B/sub fj/. Thus for a 90 K superconductor with a B/sub fj/ of 6T, a permanent field of 3 T should be trapped, with an energy product of 1.8 MJ/m/sup 3/ (225 MG . Oe). This is five times as large as for the best permanent magnet materials. The authors discuss means to verify the analysis and the limitations imposed by the low critical current densities in presently available high temperature superconductors

  16. Lawful Permanent Residents - Annual Report

    Data.gov (United States)

    Department of Homeland Security — A lawful permanent resident (LPR) or 'green card' recipient is defined by immigration law as a person who has been granted lawful permanent residence in the United...

  17. Low Vision Tips

    Science.gov (United States)

    ... this page: https://medlineplus.gov/lowvision.html MedlinePlus: Low Vision Tips We are sorry. MedlinePlus no longer maintains the For Low Vision Users page. You will still find health resources ...

  18. Chemicals Industry Vision

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1996-12-01

    Chemical industry leaders articulated a long-term vision for the industry, its markets, and its technology in the groundbreaking 1996 document Technology Vision 2020 - The U.S. Chemical Industry. (PDF 310 KB).

  19. Robot Vision Library

    Science.gov (United States)

    Howard, Andrew B.; Ansar, Adnan I.; Litwin, Todd E.; Goldberg, Steven B.

    2009-01-01

    The JPL Robot Vision Library (JPLV) provides real-time robot vision algorithms for developers who are not vision specialists. The package includes algorithms for stereo ranging, visual odometry and unsurveyed camera calibration, and has unique support for very wideangle lenses

  20. Vision and vision-related outcome measures in multiple sclerosis

    DEFF Research Database (Denmark)

    Balcer, Laura J; Miller, David H; Reingold, Stephen C

    2015-01-01

    Visual impairment is a key manifestation of multiple sclerosis. Acute optic neuritis is a common, often presenting manifestation, but visual deficits and structural loss of retinal axonal and neuronal integrity can occur even without a history of optic neuritis. Interest in vision in multiple...... sclerosis is growing, partially in response to the development of sensitive visual function tests, structural markers such as optical coherence tomography and magnetic resonance imaging, and quality of life measures that give clinical meaning to the structure-function correlations that are unique...... of investigators involved in the development and study of visual outcomes in multiple sclerosis, which had, as its overriding goals, to review the state of the field and identify areas for future research. We review data and principles to help us understand the importance of vision as a model for outcomes...

  1. New permanent magnets

    Science.gov (United States)

    Müller, K.-H.; Krabbes, G.; Fink, J.; Gruß, S.; Kirchner, A.; Fuchs, G.; Schultz, L.

    2001-05-01

    Permanent magnets play an important role and are widely spread in daily-life applications. Due to their very low costs, large availability of the row materials and their high chemical stability, hard ferrites are still dominant in the permanent magnet market although their relatively poor magnetic properties are a distinct disadvantage. Today's high-performance magnets are mostly made from Nd 2Fe 14B. The aim of research is to combine the large spontaneous magnetization of 3d metals with strong anisotropy fields known from rare-earth transition-metal compounds and, at the same time, to maintain a high value of the Curie temperature. However, the number of iron-rich rare-earth intermetallics is very limited and, consequently, not much success can be noted in this field for the last 10 years. One alternative concept is to use magnetic fields trapped in type II superconductors where much higher fields can be achieved compared to conventional rare-earth magnets. Very recently, we obtained a trapped field as high as 14.4 T in a melt-textured YBCO bulk sample of a few centimeters in diameter. This is the highest value ever achieved in a bulk superconductor. The trapped field of a superconductor is not governed by the Laplace equation and, therefore, levitation works without any additional (active) stabilization. The disadvantage of these magnets is their low working temperature (of liquid nitrogen and below).

  2. Cryogenic Permanent Magnet Undulators

    International Nuclear Information System (INIS)

    Chavanne, J.; Lebec, G.; Penel, C.; Revol, F.; Kitegi, C.

    2010-01-01

    For an in-vacuum undulator operated at small gaps the permanent magnet material needs to be highly resistant to possible electron beam exposure. At room temperature, one generally uses Sm 2 Co 17 or high coercivity NdFeB magnets at the expense of a limited field performance. In a cryogenic permanent magnet undulator (CPMU), at a temperature of around 150 K, any NdFeB grade reveals a coercivity large enough to be radiation resistant. In particular, very high remanence NdFeB material can be used to build undulators with enhanced field and X-ray brilliance at high photon energy provided that the pre-baking of the undulator above 100 deg. C can be eliminated. The ESRF has developed a full scale 2 m long CPMU with a period of 18 mm. This prototype has been in operation on the ID6 test beamline since January 2008. A significant effort was put into the characterization of NdFeB material at low temperature, the development of dedicated magnetic measurement systems and cooling methods. The measured heat budget with beam is found to be larger than expected without compromising the smooth operation of the device. Leading on from this first experience, new CPMUs are currently being considered for the upgrade of the ESRF.

  3. Periodontal healing complications following extrusive and lateral luxation in the permanent dentition: a longitudinal cohort study

    DEFF Research Database (Denmark)

    Hermann, Nuno Vibe; Lauridsen, Eva Fejerskov; Christensen, Søren Steno Ahrensburg

    2012-01-01

    To analyze the risk of tooth loss and complications in periodontal ligament (PDL) healing following extrusive and lateral luxation in the permanent dentition.......To analyze the risk of tooth loss and complications in periodontal ligament (PDL) healing following extrusive and lateral luxation in the permanent dentition....

  4. Vision Assessment and Prescription of Low Vision Devices

    OpenAIRE

    Keeffe, Jill

    2004-01-01

    Assessment of vision and prescription of low vision devices are part of a comprehensive low vision service. Other components of the service include training the person affected by low vision in use of vision and other senses, mobility, activities of daily living, and support for education, employment or leisure activities. Specialist vision rehabilitation agencies have services to provide access to information (libraries) and activity centres for groups of people with impaired vision.

  5. 77 FR 33017 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2012-06-04

    .... Molenaar Mr. Molenaar, 59, has complete loss of vision in his right eye since childhood. The best corrected... examination in 2011, his ophthalmologist noted, ``It is my opinion that Gerardus C. Molenaar has sufficient vision to perform driving tasks required to operate a commercial vehicle.'' Mr. Molenaar reported that he...

  6. FPGA Vision Data Architecture

    Science.gov (United States)

    Morfopoulos, Arin C.; Pham, Thang D.

    2013-01-01

    JPL has produced a series of FPGA (field programmable gate array) vision algorithms that were written with custom interfaces to get data in and out of each vision module. Each module has unique requirements on the data interface, and further vision modules are continually being developed, each with their own custom interfaces. Each memory module had also been designed for direct access to memory or to another memory module.

  7. Vision-based interaction

    CERN Document Server

    Turk, Matthew

    2013-01-01

    In its early years, the field of computer vision was largely motivated by researchers seeking computational models of biological vision and solutions to practical problems in manufacturing, defense, and medicine. For the past two decades or so, there has been an increasing interest in computer vision as an input modality in the context of human-computer interaction. Such vision-based interaction can endow interactive systems with visual capabilities similar to those important to human-human interaction, in order to perceive non-verbal cues and incorporate this information in applications such

  8. [The Object Permanence Fallacy.] Commentary.

    Science.gov (United States)

    Bradley, Ben S.

    1996-01-01

    Suggests that Greenberg's challenge to the centrality of object permanence in developmental thinking reveals that developmentalists' theories about childhood speak about their own self-images. Notes that developmentalists have been guilty of not only the object permanence fallacy but also the genetic fallacy, or the mistaken belief that describing…

  9. Vision Rehabilitation is Part of AMD Care

    Directory of Open Access Journals (Sweden)

    August Colenbrander

    2018-01-01

    Full Text Available AMD does not just affect the retina. It severely affects people’s lives. Paying attention to this aspect will only become more important as the population ages and more otherwise healthy individuals become affected. This paper will discuss the need for teamwork to overcome the difference between medical care, which addresses the causes of AMD, and rehabilitative care, which addresses the consequences. Different aspects and different degrees of vision loss ask for different interventions. Loss of detailed vision can be addressed by a wide variety of magnification devices. The means to address this aspect are well recognized. Surround vision is largely processed pre-attentively. Its loss cannot be remediated by devices, but must be addressed through patient education to bring previously subconscious reactions to conscious awareness. Loss of contrast vision is an aspect that is not sufficiently studied. It is important for early detection, and for the safety of the patient. When the eye condition cannot be modified, environmental modifications provide the most effective remediation.

  10. 77 FR 38381 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2012-06-27

    ... weeks, accumulating 7,500 miles, and tractor-trailer combinations for 5 years, accumulating 323,000... moving violations in a CMV. Jeffrey Macysyn Mr. Macysyn, 35, has complete loss of vision in his right eye...

  11. Mechanisms of permanent loss of olfactory receptor neurons induced by the herbicide 2,6-dichlorobenzonitrile: Effects on stem cells and noninvolvement of acute induction of the inflammatory cytokine IL-6

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Fang; Fang, Cheng [Laboratory of Molecular Toxicology, Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); School of Public Health, State University of New York at Albany, NY 12201 (United States); Schnittke, Nikolai [Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States); Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States); Schwob, James E. [Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111 (United States); Ding, Xinxin, E-mail: xding@wadsworth.org [Laboratory of Molecular Toxicology, Wadsworth Center, New York State Department of Health, Albany, NY 12201 (United States); School of Public Health, State University of New York at Albany, NY 12201 (United States)

    2013-11-01

    inhibits DCBN-induced IL-6 production, but not the stem cell loss.

  12. Operational Based Vision Assessment Automated Vision Test Collection User Guide

    Science.gov (United States)

    2017-05-15

    AFRL-SA-WP-SR-2017-0012 Operational Based Vision Assessment Automated Vision Test Collection User Guide Elizabeth Shoda, Alex...June 2015 – May 2017 4. TITLE AND SUBTITLE Operational Based Vision Assessment Automated Vision Test Collection User Guide 5a. CONTRACT NUMBER... automated vision tests , or AVT. Development of the AVT was required to support threshold-level vision testing capability needed to investigate the

  13. Progress in computer vision.

    Science.gov (United States)

    Jain, A. K.; Dorai, C.

    Computer vision has emerged as a challenging and important area of research, both as an engineering and a scientific discipline. The growing importance of computer vision is evident from the fact that it was identified as one of the "Grand Challenges" and also from its prominent role in the National Information Infrastructure. While the design of a general-purpose vision system continues to be elusive machine vision systems are being used successfully in specific application elusive, machine vision systems are being used successfully in specific application domains. Building a practical vision system requires a careful selection of appropriate sensors, extraction and integration of information from available cues in the sensed data, and evaluation of system robustness and performance. The authors discuss and demonstrate advantages of (1) multi-sensor fusion, (2) combination of features and classifiers, (3) integration of visual modules, and (IV) admissibility and goal-directed evaluation of vision algorithms. The requirements of several prominent real world applications such as biometry, document image analysis, image and video database retrieval, and automatic object model construction offer exciting problems and new opportunities to design and evaluate vision algorithms.

  14. Jane Addams’ Social Vision

    DEFF Research Database (Denmark)

    Villadsen, Kaspar

    2018-01-01

    resonated with key tenets of social gospel theology, which imbued her texts with an overarching vision of humanity’s progressive history. It is suggested that Addams’ vision of a major transition in industrial society, one involving a BChristian renaissance^ and individuals’ transformation into Bsocialized...

  15. Computer vision for sports

    DEFF Research Database (Denmark)

    Thomas, Graham; Gade, Rikke; Moeslund, Thomas B.

    2017-01-01

    fixed to players or equipment is generally not possible. This provides a rich set of opportunities for the application of computer vision techniques to help the competitors, coaches and audience. This paper discusses a selection of current commercial applications that use computer vision for sports...

  16. Copenhagen Energy Vision

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Rasmus Søgaard; Connolly, David

    The short-term goal for The City of Copenhagen is a CO2 neutral energy supply by the year 2025, and the long-term vision for Denmark is a 100% renewable energy (RE) supply by the year 2050. In this project, it is concluded that Copenhagen plays a key role in this transition. The long-term vision...

  17. Modeling foveal vision

    NARCIS (Netherlands)

    Florack, L.M.J.; Sgallari, F.; Murli, A.; Paragios, N.

    2007-01-01

    geometric model is proposed for an artificial foveal vision system, and its plausibility in the context of biological vision is explored. The model is based on an isotropic, scale invariant two-form that describes the spatial layout of receptive fields in the the visual sensorium (in the biological

  18. Machine Vision Handbook

    CERN Document Server

    2012-01-01

    The automation of visual inspection is becoming more and more important in modern industry as a consistent, reliable means of judging the quality of raw materials and manufactured goods . The Machine Vision Handbook  equips the reader with the practical details required to engineer integrated mechanical-optical-electronic-software systems. Machine vision is first set in the context of basic information on light, natural vision, colour sensing and optics. The physical apparatus required for mechanized image capture – lenses, cameras, scanners and light sources – are discussed followed by detailed treatment of various image-processing methods including an introduction to the QT image processing system. QT is unique to this book, and provides an example of a practical machine vision system along with extensive libraries of useful commands, functions and images which can be implemented by the reader. The main text of the book is completed by studies of a wide variety of applications of machine vision in insp...

  19. Light Vision Color

    Science.gov (United States)

    Valberg, Arne

    2005-04-01

    Light Vision Color takes a well-balanced, interdisciplinary approach to our most important sensory system. The book successfully combines basics in vision sciences with recent developments from different areas such as neuroscience, biophysics, sensory psychology and philosophy. Originally published in 1998 this edition has been extensively revised and updated to include new chapters on clinical problems and eye diseases, low vision rehabilitation and the basic molecular biology and genetics of colour vision. Takes a broad interdisciplinary approach combining basics in vision sciences with the most recent developments in the area Includes an extensive list of technical terms and explanations to encourage student understanding Successfully brings together the most important areas of the subject in to one volume

  20. Panoramic stereo sphere vision

    Science.gov (United States)

    Feng, Weijia; Zhang, Baofeng; Röning, Juha; Zong, Xiaoning; Yi, Tian

    2013-01-01

    Conventional stereo vision systems have a small field of view (FOV) which limits their usefulness for certain applications. While panorama vision is able to "see" in all directions of the observation space, scene depth information is missed because of the mapping from 3D reference coordinates to 2D panoramic image. In this paper, we present an innovative vision system which builds by a special combined fish-eye lenses module, and is capable of producing 3D coordinate information from the whole global observation space and acquiring no blind area 360°×360° panoramic image simultaneously just using single vision equipment with one time static shooting. It is called Panoramic Stereo Sphere Vision (PSSV). We proposed the geometric model, mathematic model and parameters calibration method in this paper. Specifically, video surveillance, robotic autonomous navigation, virtual reality, driving assistance, multiple maneuvering target tracking, automatic mapping of environments and attitude estimation are some of the applications which will benefit from PSSV.

  1. How to Make Low Vision "Sexy": A Starting Point for Interdisciplinary Student Recruitment

    Science.gov (United States)

    Wittich, Walter; Strong, Graham; Renaud, Judith; Southall, Kenneth

    2007-01-01

    Professionals in the field of low vision are increasingly concerned about the paucity of optometry students who are expressing any interest in low vision as a clinical subspecialty. Concurrent with this apparent disinterest is an increased demand for these services as the baby boomer population becomes more predisposed to age-related vision loss.…

  2. Age-Related Psychophysical Changes and Low Vision

    Science.gov (United States)

    Dagnelie, Gislin

    2013-01-01

    When considering the burden of visual impairment on aging individuals and society at large, it is important to bear in mind that vision changes are a natural aspect of aging. In this article, we consider vision changes that are part of normal aging, the prevalence of abnormal vision changes caused by disorders of the visual system, and the anticipated incidence and impact of visual impairment as the US population ages. We then discuss the services available to reduce the impact of vision loss, and the extent to which those services can and should be improved, not only to be better prepared for the anticipated increase in low vision over the coming decades, but also to increase the awareness of interactions between visual impairment and comorbidities that are common among the elderly. Finally, we consider how to promote improved quality, availability, and acceptance of low vision care to lessen the impact of visual impairment on individuals, and its burden on society. PMID:24335074

  3. Topology optimized permanent magnet systems

    Science.gov (United States)

    Bjørk, R.; Bahl, C. R. H.; Insinga, A. R.

    2017-09-01

    Topology optimization of permanent magnet systems consisting of permanent magnets, high permeability iron and air is presented. An implementation of topology optimization for magnetostatics is discussed and three examples are considered. The Halbach cylinder is topology optimized with iron and an increase of 15% in magnetic efficiency is shown. A topology optimized structure to concentrate a homogeneous field is shown to increase the magnitude of the field by 111%. Finally, a permanent magnet with alternating high and low field regions is topology optimized and a Λcool figure of merit of 0.472 is reached, which is an increase of 100% compared to a previous optimized design.

  4. Topology optimized permanent magnet systems

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Bahl, Christian; Insinga, Andrea Roberto

    2017-01-01

    Topology optimization of permanent magnet systems consisting of permanent magnets, high permeability iron and air is presented. An implementation of topology optimization for magnetostatics is discussed and three examples are considered. The Halbach cylinder is topology optimized with iron...... and an increase of 15% in magnetic efficiency is shown. A topology optimized structure to concentrate a homogeneous field is shown to increase the magnitude of the field by 111%. Finally, a permanent magnet with alternating high and low field regions is topology optimized and a ΛcoolΛcool figure of merit of 0...

  5. Periodic permanent magnet focused klystron

    Science.gov (United States)

    Ferguson, Patrick; Read, Michael; Ives, R Lawrence

    2015-04-21

    A periodic permanent magnet (PPM) klystron has beam transport structures and RF cavity structures, each of which has permanent magnets placed substantially equidistant from a beam tunnel formed about the central axis, and which are also outside the extent of a cooling chamber. The RF cavity sections also have permanent magnets which are placed substantially equidistant from the beam tunnel, but which include an RF cavity coupling to the beam tunnel for enhancement of RF carried by an electron beam in the beam tunnel.

  6. Lawful Permanent Residents Fiscal Year 2014 Country

    Data.gov (United States)

    Department of Homeland Security — Lawful permanent residents (LPRs) are foreign nationals who have been granted the right to reside permanently in the United States. LPRs are also known as 'permanent...

  7. Lawful Permanent Residents Fiscal Year 2011 State

    Data.gov (United States)

    Department of Homeland Security — Lawful permanent residents (LPRs) are foreign nationals who have been granted the right to reside permanently in the United States. LPRs are also known as 'permanent...

  8. Lawful Permanent Residents Fiscal Year 2015 Country

    Data.gov (United States)

    Department of Homeland Security — Lawful permanent residents (LPRs) are foreign nationals who have been granted the right to reside permanently in the United States. LPRs are also known as 'permanent...

  9. Lawful Permanent Residents Fiscal Year 2016 State

    Data.gov (United States)

    Department of Homeland Security — Lawful permanent residents (LPRs) are foreign nationals who have been granted the right to reside permanently in the United States. LPRs are also known as 'permanent...

  10. Lawful Permanent Residents Fiscal Year 2014 State

    Data.gov (United States)

    Department of Homeland Security — Lawful permanent residents (LPRs) are foreign nationals who have been granted the right to reside permanently in the United States. LPRs are also known as 'permanent...

  11. Lawful Permanent Residents Fiscal Year 2015 State

    Data.gov (United States)

    Department of Homeland Security — Lawful permanent residents (LPRs) are foreign nationals who have been granted the right to reside permanently in the United States. LPRs are also known as 'permanent...

  12. Perda precoce de molares permanentes e fatores associados em escolares de 9, 12 e 15 anos da rede pública municipal de Campina Grande, Estado da Paraíba, Brasil = Early loss of permanent molars and associated factors in schoolchildren aged 9, 12 and 15 years attending public schools in Campina Grande, Paraíba State, Brazil

    Directory of Open Access Journals (Sweden)

    Francineide Guimarães Carneiro de Melo

    2011-01-01

    Full Text Available Este estudo avaliou a perda precoce de molares permanentes em escolares da rede pública de Campina Grande, Estado da Paraíba, com idades de nove, 12 e 15 anos. A amostra compreendeu 873 escolares, aleatoriamente selecionados. O instrumento de coleta consistiu de um questionário e de uma ficha clínica. As variáveis do estudo compreenderam os aspectos relativos à perda dentária (tipo de elemento dental, localização na arcada dentária e a região do arco, à prevenção e à autopercepção em saúde bucal. A análise estatística compreendeu a distribuição de frequências e os testes do Qui-quadrado e Exato de Fisher. Os resultados revelaram a prevalência de 17,2% de perda dentária, sem diferenças entre os sexos, frequência de escovação e palestra educativa (p > 0,05. Os elementos dentários 36 (42,5% e 46 (33,9% foram os mais frequentemente perdidos. Observou-se a associação positiva entre perda dentária e as variáveis idade, visita ao cirurgião-dentista (OR = 2,19; IC95%: 1,35-3,59, satisfação com o sorriso (OR = 0,40; IC95%: 0,24-0,65 e a dificuldade na mastigação (OR = 2,16; IC95%: 1,48- 3,16. Conclui-se que a prevalência da perda precoce de molares permanentes foi elevada, sendo necessária a imediata adoção de ações curativas a fim de reduzir a perda precoce desses elementos dentários.This study evaluate the early loss of permanent molars in schoolchildren aged 9, 12 and 15 years attending public schools in the city of Campina Grande, Paraíba State, Brazil. The sample was composed of 873 randomly selected schoolchildren. The instrument for data collection was a questionnaire and a clinical chart. The following variables were analyzed: tooth loss (tooth type, localization in the dental arch and region of the arch, prevention and selfperception of oral health. The statistical analysis was done by frequency distribution and the chisquare and fisher’s exact tests were used. The results showed a prevalence of

  13. Permanent magnet machine with windings having strand transposition

    Science.gov (United States)

    Qu, Ronghai; Jansen, Patrick Lee

    2009-04-21

    This document discusses, among other things, a stator with transposition between the windings or coils. The coils are free from transposition to increase the fill factor of the stator slots. The transposition at the end connections between an inner coil and an outer coil provide transposition to reduce circulating current loss. The increased fill factor reduces further current losses. Such a stator is used in a dual rotor, permanent magnet machine, for example, in a compressor pump, wind turbine gearbox, wind turbine rotor.

  14. Stereo Vision Inside Tire

    Science.gov (United States)

    2015-08-21

    1 Stereo Vision Inside Tire P.S. Els C.M. Becker University of Pretoria W911NF-14-1-0590 Final...Stereo Vision Inside Tire 5a. CONTRACT NUMBER W911NF-14-1-0590 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Prof PS Els CM...on the development of a stereo vision system that can be mounted inside a rolling tire , known as T2-CAM for Tire -Terrain CAMera. The T2-CAM system

  15. delta-vision

    Data.gov (United States)

    California Natural Resource Agency — Delta Vision is intended to identify a strategy for managing the Sacramento-San Joaquin Delta as a sustainable ecosystem that would continue to support environmental...

  16. Computer Vision Syndrome.

    Science.gov (United States)

    Randolph, Susan A

    2017-07-01

    With the increased use of electronic devices with visual displays, computer vision syndrome is becoming a major public health issue. Improving the visual status of workers using computers results in greater productivity in the workplace and improved visual comfort.

  17. INSA: Vision and Activities

    International Nuclear Information System (INIS)

    Choe, Kwan-Kyoo

    2013-01-01

    INSA vision: Contribution to the world peace via advanced and excellent nuclear nonproliferation and security education and training; Objectives: Provide practical education and training programs; Raise internationally-recognized experts; Improve awareness about nuclear nonproliferation and security

  18. Design and simulation of permanent magnet synchronous motor control system

    Science.gov (United States)

    Li, Li; Liu, Yongqiu

    2018-06-01

    In recent years, with the development of power electronics, microelectronics, new motor control theory and rare earth permanent magnet materials, permanent magnet synchronous motors have been rapidly applied. Permanent magnet synchronous motors have the advantages of small size, low loss and high efficiency. Today, energy conservation and environmental protection are increasingly valued. It is very necessary to study them. Permanent magnet synchronous motor control system has a wide range of application prospects in the fields of electric vehicles, ships and other transportation. Using the simulation function of MATLAB/SIMULINK, a modular design structure was used to simulate the whole system model of speed loop adjustment, current PI modulation, SVPWM (Space Vector Pulse Width Module) wave generation and double closed loop. The results show that this control method has good robustness, and this method can improve the design efficiency and shorten the system design time. In this article, the analysis of the control principle of modern permanent magnet synchronous motor and the various processes of MATLAB simulation application will be analyzed in detail. The basic theory, basic method and application technology of the permanent magnet synchronous motor control system are systematically introduced.

  19. Biofeedback for Better Vision

    Science.gov (United States)

    1990-01-01

    Biofeedtrac, Inc.'s Accommotrac Vision Trainer, invented by Dr. Joseph Trachtman, is based on vision research performed by Ames Research Center and a special optometer developed for the Ames program by Stanford Research Institute. In the United States, about 150 million people are myopes (nearsighted), who tend to overfocus when they look at distant objects causing blurry distant vision, or hyperopes (farsighted), whose vision blurs when they look at close objects because they tend to underfocus. The Accommotrac system is an optical/electronic system used by a doctor as an aid in teaching a patient how to contract and relax the ciliary body, the focusing muscle. The key is biofeedback, wherein the patient learns to control a bodily process or function he is not normally aware of. Trachtman claims a 90 percent success rate for correcting, improving or stopping focusing problems. The Vision Trainer has also proved effective in treating other eye problems such as eye oscillation, cross eyes, and lazy eye and in professional sports to improve athletes' peripheral vision and reaction time.

  20. Design and Analysis of a Permanent Magnet Generator for Naval Applications

    Science.gov (United States)

    2005-06-01

    Miller, Design of Brushless Permanent Magnet Motors , Magna Physics Publishing and Clarendon Press, 1994. [19] James L. Kirtley, "Course 6.685: Electric...Kirtley & Edward C. Lovelace, "Drag Loss in Retaining Rings of Permanent Magnet Motors ," SatCon Technology Corporation, March, 2003. [66] H. Polinder

  1. Vision and vision-related outcome measures in multiple sclerosis

    Science.gov (United States)

    Balcer, Laura J.; Miller, David H.; Reingold, Stephen C.

    2015-01-01

    Visual impairment is a key manifestation of multiple sclerosis. Acute optic neuritis is a common, often presenting manifestation, but visual deficits and structural loss of retinal axonal and neuronal integrity can occur even without a history of optic neuritis. Interest in vision in multiple sclerosis is growing, partially in response to the development of sensitive visual function tests, structural markers such as optical coherence tomography and magnetic resonance imaging, and quality of life measures that give clinical meaning to the structure-function correlations that are unique to the afferent visual pathway. Abnormal eye movements also are common in multiple sclerosis, but quantitative assessment methods that can be applied in practice and clinical trials are not readily available. We summarize here a comprehensive literature search and the discussion at a recent international meeting of investigators involved in the development and study of visual outcomes in multiple sclerosis, which had, as its overriding goals, to review the state of the field and identify areas for future research. We review data and principles to help us understand the importance of vision as a model for outcomes assessment in clinical practice and therapeutic trials in multiple sclerosis. PMID:25433914

  2. VISION- REQUIREMENT FOR A SUCCESSFUL LEADER

    Directory of Open Access Journals (Sweden)

    Angela - Olimpia Lobonea (Oltean

    2014-12-01

    Full Text Available These people were called in the past chiefs, rulers. Now they are known as leaders. After management by objectives, strategic planning, project organization, this concept appears as a tool called "fourth generation". It is called VISION. Leadership and vision exist in the actual sense, which has become modern a few decades ago, managing to gather during this time a variety of scientific instruments. The connection between these two domains creates a certain type of leader, the visionary leader. The hypothesis from which we start is that all active leaders have a vision of what needs to be accomplished, and the inability to predict something that could be provided involves loss the capacity of the leader. Without vision, the energy reaches the lowest quotas, production decreases, terms limits are exceeded and human resources begin to dissipate.. The conclusion is that visionary leaders are endowed with multiple attributes (multiple intelligence, even if sometimes the role of intuition and unconscious in building vision at the expense of reason that is based on experience and facts is exaggerated.

  3. Transient or permanent fisheye views

    DEFF Research Database (Denmark)

    Jakobsen, Mikkel Rønne; Hornbæk, Kasper

    2012-01-01

    Transient use of information visualization may support specific tasks without permanently changing the user interface. Transient visualizations provide immediate and transient use of information visualization close to and in the context of the user’s focus of attention. Little is known, however......, about the benefits and limitations of transient visualizations. We describe an experiment that compares the usability of a fisheye view that participants could call up temporarily, a permanent fisheye view, and a linear view: all interfaces gave access to source code in the editor of a widespread...... programming environment. Fourteen participants performed varied tasks involving navigation and understanding of source code. Participants used the three interfaces for between four and six hours in all. Time and accuracy measures were inconclusive, but subjective data showed a preference for the permanent...

  4. Case Report: Use of Sports and Performance Vision Training to Benefit a Low-vision Patient's Function.

    Science.gov (United States)

    Laby, Daniel M

    2018-05-17

    Despite our inability to attenuate the course of many ocular diseases that can ultimately lead to loss or significantly decreased visual function, this report describes a potential technique to aid such patients in maximizing the use of the vision that remains. The aim of this study was to demonstrate the applicability of utilizing sports vision training to improve objective and subjective visuomotor function in a low-vision patient. A 37-year-old woman with Usher syndrome presented with reduced central visual acuity and visual field. Although we were unable to reverse the damage resulting from her diagnosis, we were able to improve the use of the remaining vision. A 27 to 31% improvement in hand-eye coordination was achieved along with a 41% improvement in object tracking and visual concentration. Most importantly, following the 14-week training period, there was also a subjective improvement in the patient's appreciation of her visual ability. The sports vision literature cites many examples in which sports vision training is useful in improving visuomotor and on-field performance. We hypothesized that these techniques may be used to aid not only athletes but also patients with low vision. Despite suffering from reduced acuity and a limited visual field, these patients often still have a significant amount of vision ability that can be used to guide motor actions. Using techniques to increase the efficient use of this remaining vision may reduce the impact of the reduced visual function and aid in activities of daily living.

  5. Connecting Temporary and Permanent Organizing

    DEFF Research Database (Denmark)

    Stjerne, Iben Sandal; Velikova, Silviya Svejenova

    2016-01-01

    This paper investigates the relationship between a permanent organization and a series of temporary organizations. It draws on an in-depth study of the process through which a Danish film production company, seeking to balance innovation and persistence in a troubled industry, struggles to realize...... a novel children’s film and its sequels. The study reveals tensions at different levels as well as boundary work and boundary roles that address them, bringing in shadows of past and future projects. The study extends the understanding of the dialectic between temporary and permanent organizing...

  6. [Quality system Vision 2000].

    Science.gov (United States)

    Pasini, Evasio; Pitocchi, Oreste; de Luca, Italo; Ferrari, Roberto

    2002-12-01

    A recent document of the Italian Ministry of Health points out that all structures which provide services to the National Health System should implement a Quality System according to the ISO 9000 standards. Vision 2000 is the new version of the ISO standard. Vision 2000 is less bureaucratic than the old version. The specific requests of the Vision 2000 are: a) to identify, to monitor and to analyze the processes of the structure, b) to measure the results of the processes so as to ensure that they are effective, d) to implement actions necessary to achieve the planned results and the continual improvement of these processes, e) to identify customer requests and to measure customer satisfaction. Specific attention should be also dedicated to the competence and training of the personnel involved in the processes. The principles of the Vision 2000 agree with the principles of total quality management. The present article illustrates the Vision 2000 standard and provides practical examples of the implementation of this standard in cardiological departments.

  7. IDA's Energy Vision 2050

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik; Hansen, Kenneth

    IDA’s Energy Vision 2050 provides a Smart Energy System strategy for a 100% renewable Denmark in 2050. The vision presented should not be regarded as the only option in 2050 but as one scenario out of several possibilities. With this vision the Danish Society of Engineers, IDA, presents its third...... contribution for an energy strategy for Denmark. The IDA’s Energy Plan 2030 was prepared in 2006 and IDA’s Climate Plan was prepared in 2009. IDA’s Energy Vision 2050 is developed for IDA by representatives from The Society of Engineers and by a group of researchers at Aalborg University. It is based on state......-of-the-art knowledge about how low cost energy systems can be designed while also focusing on long-term resource efficiency. The Energy Vision 2050 has the ambition to focus on all parts of the energy system rather than single technologies, but to have an approach in which all sectors are integrated. While Denmark...

  8. Colour, vision and ergonomics.

    Science.gov (United States)

    Pinheiro, Cristina; da Silva, Fernando Moreira

    2012-01-01

    This paper is based on a research project - Visual Communication and Inclusive Design-Colour, Legibility and Aged Vision, developed at the Faculty of Architecture of Lisbon. The research has the aim of determining specific design principles to be applied to visual communication design (printed) objects, in order to be easily read and perceived by all. This study target group was composed by a selection of socially active individuals, between 55 and 80 years, and we used cultural events posters as objects of study and observation. The main objective is to overlap the study of areas such as colour, vision, older people's colour vision, ergonomics, chromatic contrasts, typography and legibility. In the end we will produce a manual with guidelines and information to apply scientific knowledge into the communication design projectual practice. Within the normal aging process, visual functions gradually decline; the quality of vision worsens, colour vision and contrast sensitivity are also affected. As people's needs change along with age, design should help people and communities, and improve life quality in the present. Applying principles of visually accessible design and ergonomics, the printed design objects, (or interior spaces, urban environments, products, signage and all kinds of visually information) will be effective, easier on everyone's eyes not only for visually impaired people but also for all of us as we age.

  9. Experimental Evaluation of a Motor Integrated Permanent Magnet Gear

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Frandsen, Tommy; Jensen, Kasper Køtter

    2011-01-01

    This paper presents test results of a new motor integrated permanent magnet gear and clarifies a path for future optimizations. The prototype, which fabrication also is described, is initially targeting electrical traction for vehicles. Basic measured parameters in form of back-emf, stall torque...... and inductances are all in line with finite element calculations. However very high rotational losses are present in the prototype and these losses are higher than the calculations. Some of the losses are present due to poor aspects in the fabrication of the prototype, while others are identified to be caused...... by a non optimal diameter/length aspect ratio. The torque density is superior, the copper losses is only a fraction of the copper losses in other traction motors. With the proposed aspects to reduce the rotational losses is it believed that the unit has a great potential....

  10. Vision restoration after brain and retina damage: the "residual vision activation theory".

    Science.gov (United States)

    Sabel, Bernhard A; Henrich-Noack, Petra; Fedorov, Anton; Gall, Carolin

    2011-01-01

    Vision loss after retinal or cerebral visual injury (CVI) was long considered to be irreversible. However, there is considerable potential for vision restoration and recovery even in adulthood. Here, we propose the "residual vision activation theory" of how visual functions can be reactivated and restored. CVI is usually not complete, but some structures are typically spared by the damage. They include (i) areas of partial damage at the visual field border, (ii) "islands" of surviving tissue inside the blind field, (iii) extrastriate pathways unaffected by the damage, and (iv) downstream, higher-level neuronal networks. However, residual structures have a triple handicap to be fully functional: (i) fewer neurons, (ii) lack of sufficient attentional resources because of the dominant intact hemisphere caused by excitation/inhibition dysbalance, and (iii) disturbance in their temporal processing. Because of this resulting activation loss, residual structures are unable to contribute much to everyday vision, and their "non-use" further impairs synaptic strength. However, residual structures can be reactivated by engaging them in repetitive stimulation by different means: (i) visual experience, (ii) visual training, or (iii) noninvasive electrical brain current stimulation. These methods lead to strengthening of synaptic transmission and synchronization of partially damaged structures (within-systems plasticity) and downstream neuronal networks (network plasticity). Just as in normal perceptual learning, synaptic plasticity can improve vision and lead to vision restoration. This can be induced at any time after the lesion, at all ages and in all types of visual field impairments after retinal or brain damage (stroke, neurotrauma, glaucoma, amblyopia, age-related macular degeneration). If and to what extent vision restoration can be achieved is a function of the amount of residual tissue and its activation state. However, sustained improvements require repetitive

  11. Integrating National Space Visions

    Science.gov (United States)

    Sherwood, Brent

    2006-01-01

    This paper examines value proposition assumptions for various models nations may use to justify, shape, and guide their space programs. Nations organize major societal investments like space programs to actualize national visions represented by leaders as investments in the public good. The paper defines nine 'vision drivers' that circumscribe the motivations evidently underpinning national space programs. It then describes 19 fundamental space activity objectives (eight extant and eleven prospective) that nations already do or could in the future use to actualize the visions they select. Finally the paper presents four contrasting models of engagement among nations, and compares these models to assess realistic pounds on the pace of human progress in space over the coming decades. The conclusion is that orthogonal engagement, albeit unlikely because it is unprecedented, would yield the most robust and rapid global progress.

  12. Interoperability Strategic Vision

    Energy Technology Data Exchange (ETDEWEB)

    Widergren, Steven E.; Knight, Mark R.; Melton, Ronald B.; Narang, David; Martin, Maurice; Nordman, Bruce; Khandekar, Aditya; Hardy, Keith S.

    2018-02-28

    The Interoperability Strategic Vision whitepaper aims to promote a common understanding of the meaning and characteristics of interoperability and to provide a strategy to advance the state of interoperability as applied to integration challenges facing grid modernization. This includes addressing the quality of integrating devices and systems and the discipline to improve the process of successfully integrating these components as business models and information technology improve over time. The strategic vision for interoperability described in this document applies throughout the electric energy generation, delivery, and end-use supply chain. Its scope includes interactive technologies and business processes from bulk energy levels to lower voltage level equipment and the millions of appliances that are becoming equipped with processing power and communication interfaces. A transformational aspect of a vision for interoperability in the future electric system is the coordinated operation of intelligent devices and systems at the edges of grid infrastructure. This challenge offers an example for addressing interoperability concerns throughout the electric system.

  13. Telerehabilitation for people with low vision.

    Science.gov (United States)

    Bittner, Ava K; Wykstra, Stephanie L; Yoshinaga, Patrick D; Li, Tianjing

    2015-08-31

    Low vision affects over 300 million people worldwide and can compromise both activities of daily living and quality of life. Rehabilitative training and vision assistive equipment (VAE) may help, but some visually impaired people have limited resources to attend in-person visits at rehabilitation clinics. These people may be able to overcome barriers to care through remote, Internet-based consultation (i.e., telerehabilitation). To compare the effects of telerehabilitation with face-to-face (e.g., in-office or inpatient) vision rehabilitation services for improving vision-related quality of life and reading speed in people with visual function loss due to any ocular condition. Secondary objectives are to evaluate compliance with scheduled rehabilitation sessions, abandonment rates for visual assistive equipment devices, and patient satisfaction ratings. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015 Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1980 to June 2015), EMBASE (January 1980 to June 2015), PubMed (1980 to June 2015), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any language restriction or study design filter in the electronic searches; however, we restricted the searches from 1980 onwards because the Internet was not introduced to the public until 1982. We last searched the electronic databases on 15 June 2015. We planned to include randomized controlled trials (RCTs) or controlled clinical trials (CCTs) in which participants were diagnosed with low vision and were undergoing low vision rehabilitation using an Internet, web-based technology compared with an approach based on in-person consultations. Two authors independently screened titles and abstracts, and then full-text articles against

  14. High performance permanent magnet materials

    International Nuclear Information System (INIS)

    Sankar, S.G.; Herbst, J.F.; Koon, N.C.

    1987-01-01

    This book contains 25 selections. Some of the titles are: Initial magnetization behavior of rapidly quenched neodymium-iron-boron magnets; Optimization of liquid dynamic compaction for Fe-Nd-B magnet alloys; Misch-metal and/or aluminum substitutions in Nd-Fe-B permanent magnets; and NdFeB magnets with improved temperature characteristics

  15. OAS :: Member States : Permanent Representatives

    Science.gov (United States)

    Rights Actions against Corruption C Children Civil Registry Civil Society Contact Us Culture Cyber Barbados Belize Bolivia Brazil Canada Chile Colombia Costa Rica Cuba 1 Dominica (Commonwealth of) Dominican Gutierez Ambassador, Permanent Representative of Belize Diego Pary Rodríguez Bolivia Diego Pary Rodríguez

  16. PHYSIOTHERAPY OF BLIND AND LOW VISION INDIVIDUALS

    Directory of Open Access Journals (Sweden)

    Alenka Tatjana Sterle

    2002-12-01

    Full Text Available Background. The authors present a preventive physiotherapy programme intended to improve the well-being of persons who have been blind or visually impaired since birth or experience partial or complete loss of vision later in life as a result of injury or disease.Methods. Different methods and techniques of physiotherapy, kinesitherapy and relaxation used in the rehabilitation of visually impaired persons are described.Results. The goals of timely physical treatment are to avoid unnecessary problems, such as improper posture, tension of the entire body, face and eyes, and deterioration of facial expression, that often accompany partial or complete loss of vision. Regular training improves functional skills, restores the skills that have been lost, and prevents the development of defects and consequent disorders of the locomotor apparatus.Conclusions. It is very difficult to change the life style and habits of blind and visually imapired persons. Especially elderly people who experience complete or partial loss of vision later in their lives are often left to their fate. Therefore blind and visually impaired persons of all age groups should be enrolled in a suitable rehabilitation programme that will improve the quality of their life.

  17. Representing vision and blindness.

    Science.gov (United States)

    Ray, Patrick L; Cox, Alexander P; Jensen, Mark; Allen, Travis; Duncan, William; Diehl, Alexander D

    2016-01-01

    There have been relatively few attempts to represent vision or blindness ontologically. This is unsurprising as the related phenomena of sight and blindness are difficult to represent ontologically for a variety of reasons. Blindness has escaped ontological capture at least in part because: blindness or the employment of the term 'blindness' seems to vary from context to context, blindness can present in a myriad of types and degrees, and there is no precedent for representing complex phenomena such as blindness. We explore current attempts to represent vision or blindness, and show how these attempts fail at representing subtypes of blindness (viz., color blindness, flash blindness, and inattentional blindness). We examine the results found through a review of current attempts and identify where they have failed. By analyzing our test cases of different types of blindness along with the strengths and weaknesses of previous attempts, we have identified the general features of blindness and vision. We propose an ontological solution to represent vision and blindness, which capitalizes on resources afforded to one who utilizes the Basic Formal Ontology as an upper-level ontology. The solution we propose here involves specifying the trigger conditions of a disposition as well as the processes that realize that disposition. Once these are specified we can characterize vision as a function that is realized by certain (in this case) biological processes under a range of triggering conditions. When the range of conditions under which the processes can be realized are reduced beyond a certain threshold, we are able to say that blindness is present. We characterize vision as a function that is realized as a seeing process and blindness as a reduction in the conditions under which the sight function is realized. This solution is desirable because it leverages current features of a major upper-level ontology, accurately captures the phenomenon of blindness, and can be

  18. Color Vision in Aniridia.

    Science.gov (United States)

    Pedersen, Hilde R; Hagen, Lene A; Landsend, Erlend C S; Gilson, Stuart J; Utheim, Øygunn A; Utheim, Tor P; Neitz, Maureen; Baraas, Rigmor C

    2018-04-01

    To assess color vision and its association with retinal structure in persons with congenital aniridia. We included 36 persons with congenital aniridia (10-66 years), and 52 healthy, normal trichromatic controls (10-74 years) in the study. Color vision was assessed with Hardy-Rand-Rittler (HRR) pseudo-isochromatic plates (4th ed., 2002); Cambridge Color Test and a low-vision version of the Color Assessment and Diagnosis test (CAD-LV). Cone-opsin genes were analyzed to confirm normal versus congenital color vision deficiencies. Visual acuity and ocular media opacities were assessed. The central 30° of both eyes were imaged with the Heidelberg Spectralis OCT2 to grade the severity of foveal hypoplasia (FH, normal to complete: 0-4). Five participants with aniridia had cone opsin genes conferring deutan color vision deficiency and were excluded from further analysis. Of the 31 with aniridia and normal opsin genes, 11 made two or more red-green (RG) errors on HRR, four of whom also made yellow-blue (YB) errors; one made YB errors only. A total of 19 participants had higher CAD-LV RG thresholds, of which eight also had higher CAD-LV YB thresholds, than normal controls. In aniridia, the thresholds were higher along the RG than the YB axis, and those with a complete FH had significantly higher RG thresholds than those with mild FH (P = 0.038). Additional increase in YB threshold was associated with secondary ocular pathology. Arrested foveal formation and associated alterations in retinal processing are likely to be the primary reason for impaired red-green color vision in aniridia.

  19. Bio-inspired vision

    International Nuclear Information System (INIS)

    Posch, C

    2012-01-01

    Nature still outperforms the most powerful computers in routine functions involving perception, sensing and actuation like vision, audition, and motion control, and is, most strikingly, orders of magnitude more energy-efficient than its artificial competitors. The reasons for the superior performance of biological systems are subject to diverse investigations, but it is clear that the form of hardware and the style of computation in nervous systems are fundamentally different from what is used in artificial synchronous information processing systems. Very generally speaking, biological neural systems rely on a large number of relatively simple, slow and unreliable processing elements and obtain performance and robustness from a massively parallel principle of operation and a high level of redundancy where the failure of single elements usually does not induce any observable system performance degradation. In the late 1980's, Carver Mead demonstrated that silicon VLSI technology can be employed in implementing ''neuromorphic'' circuits that mimic neural functions and fabricating building blocks that work like their biological role models. Neuromorphic systems, as the biological systems they model, are adaptive, fault-tolerant and scalable, and process information using energy-efficient, asynchronous, event-driven methods. In this paper, some basics of neuromorphic electronic engineering and its impact on recent developments in optical sensing and artificial vision are presented. It is demonstrated that bio-inspired vision systems have the potential to outperform conventional, frame-based vision acquisition and processing systems in many application fields and to establish new benchmarks in terms of redundancy suppression/data compression, dynamic range, temporal resolution and power efficiency to realize advanced functionality like 3D vision, object tracking, motor control, visual feedback loops, etc. in real-time. It is argued that future artificial vision systems

  20. Low Vision Enhancement System

    Science.gov (United States)

    1995-01-01

    NASA's Technology Transfer Office at Stennis Space Center worked with the Johns Hopkins Wilmer Eye Institute in Baltimore, Md., to incorporate NASA software originally developed by NASA to process satellite images into the Low Vision Enhancement System (LVES). The LVES, referred to as 'ELVIS' by its users, is a portable image processing system that could make it possible to improve a person's vision by enhancing and altering images to compensate for impaired eyesight. The system consists of two orientation cameras, a zoom camera, and a video projection system. The headset and hand-held control weigh about two pounds each. Pictured is Jacob Webb, the first Mississippian to use the LVES.

  1. En vision for CBS?

    DEFF Research Database (Denmark)

    Thyssen, Ole

    2015-01-01

    Kommentar. CBS’ ry for at være et moderne Business University med forskere fra hele verden og forskningsmæssig dynamik faldt på gulvet. Udfordringen er nu at få samlet CBS forskere om en fælles vision.......Kommentar. CBS’ ry for at være et moderne Business University med forskere fra hele verden og forskningsmæssig dynamik faldt på gulvet. Udfordringen er nu at få samlet CBS forskere om en fælles vision....

  2. Some examples of image warping for low vision prosthesis

    Science.gov (United States)

    Juday, Richard D.; Loshin, David S.

    1988-01-01

    NASA has developed an image processor, the Programmable Remapper, for certain functions in machine vision. The Remapper performs a highly arbitrary geometric warping of an image at video rate. It might ultimately be shrunk to a size and cost that could allow its use in a low-vision prosthesis. Coordinate warpings have been developed for retinitis pigmentosa (tunnel vision) and for maculapathy (loss of central field) that are intended to make best use of the patient's remaining viable retina. The rationales and mathematics are presented for some warpings that we will try in clinical studies using the Remapper's prototype.

  3. Near vision spectacle coverage and barriers to near vision ...

    African Journals Online (AJOL)

    easily help to address this visual disability.7 An average cost of near vision spectacle in Ghana is approximately. $ 5.8 Near-vision spectacle could be dispensed as single vision, bifocal or progressive eye glasses to meet near vi- sion needs.2. Recent evidence suggests that the ageing population in. Ghana is increasing ...

  4. Grounding Our Vision: Brain Research and Strategic Vision

    Science.gov (United States)

    Walker, Mike

    2011-01-01

    While recognizing the value of "vision," it could be argued that vision alone--at least in schools--is not enough to rally the financial and emotional support required to translate an idea into reality. A compelling vision needs to reflect substantive, research-based knowledge if it is to spark the kind of strategic thinking and insight…

  5. Effects of visual skills training, vision coaching and sports vision ...

    African Journals Online (AJOL)

    The purpose of this study was to determine the effectiveness of three different approaches to improving sports performance through improvements in “sports vision:” (1) a visual skills training programme, (2) traditional vision coaching sessions, and (3) a multi-disciplinary approach identified as sports vision dynamics.

  6. ABCs of foveal vision

    Science.gov (United States)

    Matchko, Roy M.; Gerhart, Grant R.

    2001-12-01

    This paper presents a simple mathematical performance model of the human foveal vision system based on an extensive analysis of the Blackwell-McCready (BM) data set. It includes a closed-form equation, the (ABC)t law, that allows the analyst to predict the entire range of BM threshold data. Relationships are derived among the four fundamental parameters of foveal vision: target area A, background luminance B, threshold contrast C, and stimulus presentation time t. Hyperbolic-curve fits on log-log plots of the data lead to the well-known laws of Ricco, Blackwell, Weber and Fechner, and Bloch. This paper unifies important relationships associated with target and background scene parameters as they relate to the human foveal vision process. The process of detecting a BM target, using foveal vision, is reduced to the total temporal summation of light energy modified by a multiplicative energy ratio. A stochastic model of human observer performance is presented in terms of a cumulative Gaussian distribution, which is a function of the apparent and BM contrast threshold values.

  7. Home vision tests

    Science.gov (United States)

    ... missing areas. If any lines appear distorted or broken, note their location on the grid using a pen or pencil. DISTANCE VISION This is the standard eye chart doctors use, which has been adapted for home use. The chart is attached to a wall ...

  8. VISION AND READING ABILITY.

    Science.gov (United States)

    MANGRUM, CHARLES T.

    SIGNIFICANT RESEARCH ON THE PHYSIOLOGICAL AND FUNCTIONAL ASPECTS OF VISION AND READING DISABILITY IS SURVEYED. CONCLUSIONS BASED ON THE LITERATURE IN THE FIELD ARE DISCUSSED. A BIBLIOGRAPHY OF 70 REFERENCES AND A GLOSSARY OF TERMS ARE APPENDED. A TABLE SUMMARIZING REFRACTIVE ERRORS AND EYE DEFECTS CONTRIBUTING TO READING DISABILITY IS INCLUDED.…

  9. Dance: Verities, Values, Visions.

    Science.gov (United States)

    Boorman, Joyce, Ed.; Harris, Dorothy, Ed.

    The Binational Dance Conference was organized into three focal themes--verities, values, and visions in dance--to emphasize the known and accepted worth and value of dance, and to stimulate through knowledge and idea exchange, imaginative directions for dance in the future of both the United States and Canada. This thematic structure is also the…

  10. KiWi Vision

    DEFF Research Database (Denmark)

    Schaffert, Sebastian; Bry, Francois; Dolog, Peter

    This deliverable describes the common vision of the KiWi project, ranging from motivation over use cases and usage scenarios to user interaction, system architecture and technologies, and the research that is performed as part of the project. The deliverable is intended for a wide audience to give...

  11. Direct vision internal urethrotomy

    DEFF Research Database (Denmark)

    Jakobsen, H; Willumsen, H; Søndergaard Jensen, L

    1984-01-01

    During a five-year period, direct vision internal urethrotomy was used for the treatment of urethral strictures in 34 men. After the primary operation the patients were followed for an average period of 29 months (range 3-73 months). During this period 53% of the patients were found to have one...

  12. Vision eller verklighet?

    DEFF Research Database (Denmark)

    Andersson, Jonas E

    2012-01-01

    and drawing analysis. This study suggests that there is a gap between reality and visions. Despite research-based guidelines, the architecture of contemporary residential care homes relies on universal qualities that are associated with the home environment rather than with the particular conditions...

  13. Tectonic vision in architecture

    DEFF Research Database (Denmark)

    Beim, Anne

    1999-01-01

    By introducing the concept; Tectonic Visions, The Dissertation discusses the interrelationship between the basic idea, the form principles, the choice of building technology and constructive structures within a given building. Includes Mies van der Rohe, Le Corbusier, Eames, Jorn Utzon, Louis Kahn...

  14. Vision: Essential Scaffolding

    Science.gov (United States)

    Murphy, Joseph; Torre, Daniela

    2015-01-01

    Few concepts are more noted in the leadership effects research than vision. It is a cardinal element in the school improvement equation as well. Yet, it remains one of the least well-specified components of that algorithm. Based on a comprehensive review of the research on effective leadership and school improvement from 1995 to 2012, we bring…

  15. Motion Control with Vision

    NARCIS (Netherlands)

    Ir. Dick van Schenk Brill; Ir Peter Boots

    2001-01-01

    This paper describes the work that is done by a group of I3 students at Philips CFT in Eindhoven, Netherlands. I3 is an initiative of Fontys University of Professional Education also located in Eindhoven. The work focuses on the use of computer vision in motion control. Experiments are done with

  16. INL Vision and Strategy 2015

    International Nuclear Information System (INIS)

    Pillai, Rekha Sukamar

    2015-01-01

    This Laboratory vision and strategy presents INL's vision and strategy for the Laboratory and is our introduction to a special place dedicated to improving our nation's energy security future.

  17. What is vision Hampton Roads?

    Science.gov (United States)

    2010-01-01

    What is Vision Hampton Roads? : Vision Hampton Roads is... : A regionwide economic development strategy based on the collective strengths of all : localities of Hampton Roads, created with the input of business, academia, nonprofits, : government,...

  18. Thermal Analysis on Radial Flux Permanent Magnet Generator (PMG using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Hilman Syaeful A Syaeful A

    2011-05-01

    Full Text Available The main source of heat in the permanent magnet generator (PMG is the total losses which f come from winding losses, core losses and rotational losses. Total heat arising from such these losses must be properly distributed and maintained so as not to exceed the maximum allowable temperature to prevent damage to insulation on the winding and demagnetization on the permanent magnet machines. In this research, we consider thermal analysis which is occurred on the radial flux PMG by using finite element method to determine the extent to which the heat generated can be properly distributed. The simulation results show that there are no points of heat concentration or hot spot. The simulation maximum temperatures of the permanent magnet and the winding are 39.1oC and 72.5oC respectively while the experimental maximum temperature of the winding is 62oC.

  19. Automated phenotyping of permanent crops

    Science.gov (United States)

    McPeek, K. Thomas; Steddom, Karl; Zamudio, Joseph; Pant, Paras; Mullenbach, Tyler

    2017-05-01

    AGERpoint is defining a new technology space for the growers' industry by introducing novel applications for sensor technology and data analysis to growers of permanent crops. Serving data to a state-of-the-art analytics engine from a cutting edge sensor platform, a new paradigm in precision agriculture is being developed that allows growers to understand the unique needs of each tree, bush or vine in their operation. Autonomous aerial and terrestrial vehicles equipped with multiple varieties of remote sensing technologies give AGERpoint the ability to measure key morphological and spectral features of permanent crops. This work demonstrates how such phenotypic measurements combined with machine learning algorithms can be used to determine the variety of crops (e.g., almond and pecan trees). This phenotypic and varietal information represents the first step in enabling growers with the ability to tailor their management practices to individual plants and maximize their economic productivity.

  20. Permanently calibrated interpolating time counter

    International Nuclear Information System (INIS)

    Jachna, Z; Szplet, R; Kwiatkowski, P; Różyc, K

    2015-01-01

    We propose a new architecture of an integrated time interval counter that provides its permanent calibration in the background. Time interval measurement and the calibration procedure are based on the use of a two-stage interpolation method and parallel processing of measurement and calibration data. The parallel processing is achieved by a doubling of two-stage interpolators in measurement channels of the counter, and by an appropriate extension of control logic. Such modification allows the updating of transfer characteristics of interpolators without the need to break a theoretically infinite measurement session. We describe the principle of permanent calibration, its implementation and influence on the quality of the counter. The precision of the presented counter is kept at a constant level (below 20 ps) despite significant changes in the ambient temperature (from −10 to 60 °C), which can cause a sevenfold decrease in the precision of the counter with a traditional calibration procedure. (paper)

  1. The cycloid Permanent Magnetic Gear

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Andersen, Torben Ole; Jørgensen, Frank T.

    2008-01-01

    This paper presents a new permanent-magnet gear based on the cycloid gearing principle. which normally is characterized by an extreme torque density and a very high gearing ratio. An initial design of the proposed magnetic gear was designed, analyzed, and optimized with an analytical model...... regarding torque density. The results were promising as compared to other high-performance magnetic-gear designs. A test model was constructed to verify the analytical model....

  2. What You Should Know (Low Vision)

    Science.gov (United States)

    ... Cataract Diabetic retinopathy Glaucoma Macular degeneration What is low vision? When you have low vision, eyeglasses, contact lenses, ... eyesight. How do I know if I have low vision? Below are some signs of low vision. Even ...

  3. Lawful Permanent Residents Fiscal Year 2011 Country

    Data.gov (United States)

    Department of Homeland Security — Lawful permanet residents (LPRs) are foreign nationals who have been gratned the right to reside permanently in the United States. LPRs are also known as 'permanent...

  4. Hearing loss

    Science.gov (United States)

    Decreased hearing; Deafness; Loss of hearing; Conductive hearing loss; Sensorineural hearing loss; Presbycusis ... Symptoms of hearing loss may include: Certain sounds seeming too loud Difficulty following conversations when two or more people are talking ...

  5. Vision 21: The NASA strategic plan

    Science.gov (United States)

    1992-01-01

    The NASA Strategic Plan, Vision 21, is a living roadmap to the future to guide the men and women of the NASA team as they ensure U.S. leadership in space exploration and aeronautics research. This multiyear plan consists of a set of programs and activities that will retain our leadership in space science and the exploration of the solar system; help rebuild our nation's technology base and strengthen our leadership in aviation and other key industries; encourage commercial applications of space technology; use the unique perspective of space to better understand our home planet; provide the U.S. and its partners with a permanent space based research facility; expand on the legacy of Apollo and initiate precursor activities to establish a lunar base; and allow us a journey into tomorrow, journey to another planet (Mars), and beyond.

  6. Atrial and ventricular volume and function in persistent and permanent atrial fibrillation, a magnetic resonance imaging study

    DEFF Research Database (Denmark)

    Therkelsen, Susette Krohn; Groenning, Bjoern Aaris; Svendsen, Jesper Hastrup

    2005-01-01

    the inter-study reproducibility of the measurements. Nineteen healthy volunteers, 19 patients with permanent AF, and 58 patients with persistent AF had cardiac dimensions evaluated by 6-mm cinematographic breath-hold MRI scans using a 1.5 Tesla Siemens Vision Magnetom scanner with a phased array chest coil...

  7. Teaching Object Permanence: An Action Research Study

    Science.gov (United States)

    Bruce, Susan M.; Vargas, Claudia

    2013-01-01

    "Object permanence," also known as "object concept" in the field of visual impairment, is one of the most important early developmental milestones. The achievement of object permanence is associated with the onset of representational thought and language. Object permanence is important to orientation, including the recognition of landmarks.…

  8. 21 CFR 886.4445 - Permanent magnet.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Permanent magnet. 886.4445 Section 886.4445 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4445 Permanent magnet. (a) Identification. A permanent magnet is a nonelectric device that generates a magnetic field intended to find and remove metallic...

  9. Realisering af Vision 2020

    DEFF Research Database (Denmark)

    Bertelsen, Niels Haldor; Hansen, Ernst Jan de Place

    Repræsentanter for byggesektoren har på 11 dialogmøder drøftet Erhvervs- og Byggestyrelsens "Vision 2020 - Byggeri med mening". Drøftelserne førte til formulering af en lang række initiativforslag til realisering af visionen. Den mest centrale udfordring bliver at reducere fejl og mangler i...... byggeriet. Branchen lægger også vægt på, at styringen af Vision 2020s reaisering sker i byggesektoren. Initiativforslagene er i rapporten samlet under 3 hovedområder. Det første hovedområde lægger vægt på bygningerne, brugerbehov og det globale samfund. Det andet omhandler processen og leverancesystemet...

  10. The Siemens vision

    CSIR Research Space (South Africa)

    Van Dijk, B

    2017-10-01

    Full Text Available engagement Siemens Centre of Knowledge Interchange (CKI) • Partnership and collaboration with Universities • Industry specific • Multi-million investment, annually Siemens mentors • All Siemens employees actively encouraged to engage with schools.... Siemens is an engineering company. Vision 2020 “we make what matters” including the next generation of engineers make a difference, change the world. > €20M annual donations to education. Siemens ownership culture 348,000 employees...

  11. Research for VISION 2020

    Directory of Open Access Journals (Sweden)

    Peter Ackland

    2010-12-01

    Full Text Available We need good quality information to be able to carry out our eye care programmes in support of VISION 2020, to measure (and improve our performance, and to advocate for the resources and support we need to succeed. Much of this information can be collected, analysed, and used as part of our daily work, as many of the articles in this issue show.

  12. 2015 Enterprise Strategic Vision

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-08-01

    This document aligns with the Department of Energy Strategic Plan for 2014-2018 and provides a framework for integrating our missions and direction for pursuing DOE’s strategic goals. The vision is a guide to advancing world-class science and engineering, supporting our people, modernizing our infrastructure, and developing a management culture that operates a safe and secure enterprise in an efficient manner.

  13. Vision and the hypothalamus.

    Science.gov (United States)

    Trachtman, Joseph N

    2010-02-01

    For nearly 2 millennia, signs of hypothalamic-related vision disorders have been noticed as illustrated by paintings and drawings of that time of undiagnosed Horner's syndrome. It was not until the 1800s, however, that specific connections between the hypothalamus and the vision system were discovered. With a fuller elaboration of the autonomic nervous system in the early to mid 1900s, many more pathways were discovered. The more recently discovered retinohypothalamic tracts show the extent and influence of light stimulation on hypothalamic function and bodily processes. The hypothalamus maintains its myriad connections via neural pathways, such as with the pituitary and pineal glands; the chemical messengers of the peptides, cytokines, and neurotransmitters; and the nitric oxide mechanism. As a result of these connections, the hypothalamus has involvement in many degenerative diseases. A complete feedback mechanism between the eye and hypothalamus is established by the retinohypothalamic tracts and the ciliary nerves innervating the anterior pole of the eye and the retina. A discussion of hypothalamic-related vision disorders includes neurologic syndromes, the lacrimal system, the retina, and ocular inflammation. Tables and figures have been used to aid in the explanation of the many connections and chemicals controlled by the hypothalamus. The understanding of the functions of the hypothalamus will allow the clinician to gain better insight into the many pathologies associated between the vision system and the hypothalamus. In the future, it may be possible that some ocular disease treatments will be via direct action on hypothalamic function. Copyright 2010 American Optometric Association. Published by Elsevier Inc. All rights reserved.

  14. Ecstasy and vision

    Directory of Open Access Journals (Sweden)

    Anders Hultgård

    1981-01-01

    Full Text Available In this paper we shall present some observations on the role played by ecstasy in the activity of the seer, as he emerges in ancient Jewish and Iranian texts. In the Jewish religious literature of the Hellenistic-Roman period, visions are described on almost every page, and visions were the most important means of divine revelation. Specific techniques for inducing the ecstatic state are not recorded in the Jewish sources. Some elements in the pattern leading up to the vision may be interpreted as parts of a method for inducing the final ecstasy; i.e. fasting and prayer. The Iranian material shows clearly the importance of ecstasy in the activity of the seer. The ecstatic seeing also means that the visionary shares with Ahura Mazda a divine quality, the "wisdom of omniscience". The granting of the "wisdom of omniscience" appears as a temporary and it conveys to the visionary a supernatural seeing. There is evidence to suggest that chanting was an important method of inducing ecstasy within the early Zoroastrian community. We do not find in the Jewish material a clear correspondence to the Iranian notion of "omniscient wisdom".

  15. Permanent magnets including undulators and wigglers

    CERN Document Server

    Bahrdt, J

    2010-01-01

    After a few historic remarks on magnetic materials we introduce the basic definitions related to permanent magnets. The magnetic properties of the most common materials are reviewed and the production processes are described. Measurement techniques for the characterization of macroscopic and microscopic properties of permanent magnets are presented. Field simulation techniques for permanent magnet devices are discussed. Today, permanent magnets are used in many fields. This article concentrates on the applications of permanent magnets in accelerators starting from dipoles and quadrupoles on to wigglers and undulators.

  16. Optimally segmented permanent magnet structures

    DEFF Research Database (Denmark)

    Insinga, Andrea Roberto; Bjørk, Rasmus; Smith, Anders

    2016-01-01

    We present an optimization approach which can be employed to calculate the globally optimal segmentation of a two-dimensional magnetic system into uniformly magnetized pieces. For each segment the algorithm calculates the optimal shape and the optimal direction of the remanent flux density vector......, with respect to a linear objective functional. We illustrate the approach with results for magnet design problems from different areas, such as a permanent magnet electric motor, a beam focusing quadrupole magnet for particle accelerators and a rotary device for magnetic refrigeration....

  17. Predicting Vision-Related Disability in Glaucoma.

    Science.gov (United States)

    Abe, Ricardo Y; Diniz-Filho, Alberto; Costa, Vital P; Wu, Zhichao; Medeiros, Felipe A

    2018-01-01

    To present a new methodology for investigating predictive factors associated with development of vision-related disability in glaucoma. Prospective, observational cohort study. Two hundred thirty-six patients with glaucoma followed up for an average of 4.3±1.5 years. Vision-related disability was assessed by the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) at baseline and at the end of follow-up. A latent transition analysis model was used to categorize NEI VFQ-25 results and to estimate the probability of developing vision-related disability during follow-up. Patients were tested with standard automated perimetry (SAP) at 6-month intervals, and evaluation of rates of visual field change was performed using mean sensitivity (MS) of the integrated binocular visual field. Baseline disease severity, rate of visual field loss, and duration of follow-up were investigated as predictive factors for development of disability during follow-up. The relationship between baseline and rates of visual field deterioration and the probability of vision-related disability developing during follow-up. At baseline, 67 of 236 (28%) glaucoma patients were classified as disabled based on NEI VFQ-25 results, whereas 169 (72%) were classified as nondisabled. Patients classified as nondisabled at baseline had 14.2% probability of disability developing during follow-up. Rates of visual field loss as estimated by integrated binocular MS were almost 4 times faster for those in whom disability developed versus those in whom it did not (-0.78±1.00 dB/year vs. -0.20±0.47 dB/year, respectively; P disability developing over time (odds ratio [OR], 1.34; 95% confidence interval [CI], 1.06-1.70; P = 0.013). In addition, each 0.5-dB/year faster rate of loss of binocular MS during follow-up was associated with a more than 3.5 times increase in the risk of disability developing (OR, 3.58; 95% CI, 1.56-8.23; P = 0.003). A new methodology for classification and analysis

  18. Permanent magnet-based MRI

    Science.gov (United States)

    Cole, David Mitchell

    1997-10-01

    The principal goal of this project is to design and build a low-cost, imaging quality permanent magnet, together with the requisite shim, gradient, and radiofrequency coils, and to integrate the magnet with an existing imaging station. There are commercial products presently available that are very similar to this imager, but information about these products is proprietary. We present here all of the details concerning the design and the manufacturing process for constructing the permanent magnet, and include suggestions for improvement. Specifically, the prototype has a mass of about 150 kilograms and is therefore portable. It's C-type geometry allows maximum access to the imaging region, which is an oblate sphere about 0.5 inches in diameter centered in a 4.7 inch air gap between two seven-inch diameter polefaces. It is hoped that this imaging magnet will serve as the prototype for a series of larger versions that will be clinically useful and affordable to physicians in developing nations. To this end, scientists in the United States and Mexico have begun to collaborate with the intention to create an MRI institute in Mexico that will train new students in this discipline, and fabricate improved imagers. The prototype resulting from this work will seed the creation of this institute, and is intended to entice students into the study of MRI by enabling hands-on interaction with an otherwise prohibitively expensive instrument.

  19. Permanent burying method for product

    International Nuclear Information System (INIS)

    Sakai, Goro; Sakata, Noboru; Hironaka, Yoshikazu; Shigematsu, Kazuo; Yurugi, Masahiro; Minami, Masayoshi; Yoshisaki, Masato.

    1995-01-01

    In a method of permanently burying an object by filling and solidifying a cement mortar in gaps between each of objects to be buried underground, cement mortar is filled into gaps, which comprises water at a unit amount determined as from 200 to 250kg/m 3 , a cement at low water/cement ratio (%) of from 70 to 400%, and contains fine powder having an average grain size of not greater than 100μm (not containing cement) of 50 to 800kg/m 3 , fine aggregates of 800 to 1200kg/m 3 , UERAN gum (a bio-gum powder produced by aerobic fermentation of alcaligenes-bacteria) of 20g/m 3 to 1.3kg/m 3 , a dispersing agent of 0 to 40kg/m 3 , a swelling agent of 0 to 40kg/m 3 . Then if the mortar blended with the UERAN gum is injected, any gaps can be filled tightly, no breeding is caused and since the amount of cement is small, it does not suffer from temperature cracking. Therefore, the state of filling is kept permanently, and environmental pollution caused by radioactive wastes can be prevented. (N.H.)

  20. Pregnancy Loss

    Science.gov (United States)

    ... To receive Pregnancy email updates Enter email Submit Pregnancy loss Pregnancy loss is a harsh reality faced ... have successful pregnancies. Expand all | Collapse all Why pregnancy loss happens As many as 10 to 15 ...

  1. The Impact of Residual Vision in Spatial Skills of Individuals with Visual Impairments

    Science.gov (United States)

    Papadopoulos, Konstantinos; Koustriava, Eleni; Kartasidou, Lefkothea

    2011-01-01

    Loss of vision is believed to have a great impact on the acquisition of spatial knowledge. The aims of the present study are to examine the performance of individuals with visual impairments on spatial tasks and the impact of residual vision on processing these tasks. In all, 28 individuals with visual impairments--blindness or low…

  2. Vision Problems in Homeless Children.

    Science.gov (United States)

    Smith, Natalie L; Smith, Thomas J; DeSantis, Diana; Suhocki, Marissa; Fenske, Danielle

    2015-08-01

    Vision problems in homeless children can decrease educational achievement and quality of life. To estimate the prevalence and specific diagnoses of vision problems in children in an urban homeless shelter. A prospective series of 107 homeless children and teenagers who underwent screening with a vision questionnaire, eye chart screening (if mature enough) and if vision problem suspected, evaluation by a pediatric ophthalmologist. Glasses and other therapeutic interventions were provided if necessary. The prevalence of vision problems in this population was 25%. Common diagnoses included astigmatism, amblyopia, anisometropia, myopia, and hyperopia. Glasses were required and provided for 24 children (22%). Vision problems in homeless children are common and frequently correctable with ophthalmic intervention. Evaluation by pediatric ophthalmologist is crucial for accurate diagnoses and treatment. Our system of screening and evaluation is feasible, efficacious, and reproducible in other homeless care situations.

  3. Company Vision and Organizational Learning

    Directory of Open Access Journals (Sweden)

    Vojko Toman

    2015-11-01

    Full Text Available The effectiveness of a company is largely dependent on the company itself; it depends above all on its corporate governance, management, and implementation, as well as on decision-making processes and coordination. Many authors believe that organizational learning and knowledge are the most relevant aspects of company effectiveness. If a company wants to be effective it needs to create and realize its vision; to do this, it needs creativity, imagination, and knowledge, which can be obtained or enhanced through learning. This paper defines vision, learning, creativity and management and, above all, their relationships. The author argues that company vision influences the learning and knowledge of employees in the company through the vision’s content, through the vision-creating process, and through the vision enforcement process. Conversely, the influence of learning on company vision is explained. The paper is aimed at the use in the practice of companies and helps them to increase their effectiveness.

  4. Vision as subjective perception

    International Nuclear Information System (INIS)

    Reppas, J.B.; Dale, A.; Sereno, M.; Tootell, R.

    1996-01-01

    The human brain is not very different of the monkey's one: at least, its visual cortex is organized as a similar scheme. Specialized areas in the movement analysis are found and others in the forms perception. In this work, the author tries to answer to the following questions: 1)why so many visual areas? What are exactly their role in vision? Thirteen years of experimentation have not allowed to answer to these questions. The cerebral NMR imaging gives the opportunity of understanding the subjective perception of the visual world. One step which is particularly described in this work is to know how the visual cortex reacts to the optical illusions. (O.M.)

  5. The Static Eccentricity Fault Diagnosis in Time Domain at Line Start Permanent Magnet Synchronous Motor

    OpenAIRE

    DOGAN, Zafer

    2016-01-01

    Recently, Line Start Permanent Magnet Synchronous Motor have been commonly utilized in industrial areas because of their high efficiency. Motor faults during operation cause losses of production and high maintenance and repair expenditures. In this study, the effect of static eccentricity fault on line start permanent magnet synchronous motor was investigated. The simulation models of motor belonging to healthy and fault status were formed via Finite Elements Method. The analyses in time doma...

  6. Treatment of ectopically erupting maxillary permanent first molars with a distal extended stainless steel crown.

    Science.gov (United States)

    Roberts, M W

    1986-01-01

    The exaggerated mesial eruption of the permanent first molar can result in the tooth becoming impacted, or the premature atypical resorption and exfoliation of the primary molar, with a resultant loss of space. A stainless steel crown with a distal guide plane was placed on a primary molar to correct the aberrant eruption angle of the permanent tooth. This procedure can be used successfully for both partially and totally tissue-impacted teeth, and is described in this report.

  7. Active Vision for Sociable Robots

    National Research Council Canada - National Science Library

    Breazeal, Cynthia; Edsinger, Aaron; Fitzpatrick, Paul; Scassellati, Brian

    2001-01-01

    .... In humanoid robotic systems, or in any animate vision system that interacts with people, social dynamics provide additional levels of constraint and provide additional opportunities for processing economy...

  8. Social Constraints on Animate Vision

    National Research Council Canada - National Science Library

    Breazeal, Cynthia; Edsinger, Aaron; Fitzpatrick, Paul; Scassellati, Brian

    2000-01-01

    .... In humanoid robotic systems, or in any animate vision system that interacts with people, social dynamics provide additional levels of constraint and provide additional opportunities for processing economy...

  9. Advance and permanent public information

    International Nuclear Information System (INIS)

    d'Oleon, C.

    1990-01-01

    The accident at CHERNOBYL highlighted one of the major problems facing the nuclear industry at present and during the years to come: the need to provide information. There are two aspects to this requirement: information at a time of crisis issued when an accident such as that at CHERNOBYL takes place, but which has to be based on a procedure set up before the crisis, and advance and permanent information which prepares the ground for information at a time of crisis. The requirement for information is of particular importance in France, given the preponderance of nuclear energy in the electricity generating industry. The procedure covers the principles which were forcefully asserted by the French public authorities during the CHERNOBYL crisis, the resources strengthened or established at that time, and finally, the introduction of a policy of wider-ranging communication which is based on the idea that one can never compromise with safety

  10. CHALLENGES OF PERMANENT TEACHER TRAINING

    Directory of Open Access Journals (Sweden)

    María Manuela Valles-Ornelas

    2015-07-01

    Full Text Available The new challenges for teachers and managers require to assume permanent formation as a tool for responding effectively and efficiently to them, different perspective to strengthen from the initial teacher education programs. The research was done in a primary school in the state of Chihuahua. The method used was research action, the question was: How can we encourage the lifelong learning and training of the staff of this school, with the purpose to assist them in these processes to improve the service that the school provides to students. The school group is the center of the process, the cooperative and collaborative work accompanied by educational leadership and persuasive provide better results, and all accompanied by the professional selfinvitation.

  11. Coherent laser vision system

    International Nuclear Information System (INIS)

    Sebastion, R.L.

    1995-01-01

    The Coherent Laser Vision System (CLVS) is being developed to provide precision real-time 3D world views to support site characterization and robotic operations and during facilities Decontamination and Decommissioning. Autonomous or semiautonomous robotic operations requires an accurate, up-to-date 3D world view. Existing technologies for real-time 3D imaging, such as AM laser radar, have limited accuracy at significant ranges and have variability in range estimates caused by lighting or surface shading. Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no-moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic to coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system

  12. Energy visions 2050

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    Energy Visions 2050 considers measures for addressing the enormous future challenges facing the energy sector, focusing on technological and techno-economic perspectives. The analysis of the development of technologies covers the whole energy chain, highlighting the necessity of efficient energy use in all activities of societies. The contents include a discussion on potential future low-emission and renewable energy conversion technologies, as well as new technology solutions in the industrial, building and transport sectors and in energy supply systems. The move towards zero-emission energy systems has consequenses for energy supply, and makes the analysis of energy resources presented in the book all the more valuable. Scenarios of alternative development paths to 2050 at the global, European and Finnish levels are presented, assuming different technological development options, economic growth rates, degrees of globalisation and information flows. The results show interesting differences between the scenarios with regard to energy production and use, mitigation of greenhouse gas emissions, and global warming. Energy Visions 2050 in mainly intended for those who have a fairly good knowledge of the energy sector and energy technologies, e.g. energy policymakers, experts responsible for energy-related issues in industry, and investors in energy technologies. The topics are approached from a global perspective. In some technological details, however, Finnish technology and Finland's technological achievements are highlighted. The topics and viewpoints of the book will certainly be of interest to international readers as well

  13. Coherent laser vision system

    Energy Technology Data Exchange (ETDEWEB)

    Sebastion, R.L. [Coleman Research Corp., Springfield, VA (United States)

    1995-10-01

    The Coherent Laser Vision System (CLVS) is being developed to provide precision real-time 3D world views to support site characterization and robotic operations and during facilities Decontamination and Decommissioning. Autonomous or semiautonomous robotic operations requires an accurate, up-to-date 3D world view. Existing technologies for real-time 3D imaging, such as AM laser radar, have limited accuracy at significant ranges and have variability in range estimates caused by lighting or surface shading. Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no-moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic to coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

  14. Python and computer vision

    Energy Technology Data Exchange (ETDEWEB)

    Doak, J. E. (Justin E.); Prasad, Lakshman

    2002-01-01

    This paper discusses the use of Python in a computer vision (CV) project. We begin by providing background information on the specific approach to CV employed by the project. This includes a brief discussion of Constrained Delaunay Triangulation (CDT), the Chordal Axis Transform (CAT), shape feature extraction and syntactic characterization, and normalization of strings representing objects. (The terms 'object' and 'blob' are used interchangeably, both referring to an entity extracted from an image.) The rest of the paper focuses on the use of Python in three critical areas: (1) interactions with a MySQL database, (2) rapid prototyping of algorithms, and (3) gluing together all components of the project including existing C and C++ modules. For (l), we provide a schema definition and discuss how the various tables interact to represent objects in the database as tree structures. (2) focuses on an algorithm to create a hierarchical representation of an object, given its string representation, and an algorithm to match unknown objects against objects in a database. And finally, (3) discusses the use of Boost Python to interact with the pre-existing C and C++ code that creates the CDTs and CATS, performs shape feature extraction and syntactic characterization, and normalizes object strings. The paper concludes with a vision of the future use of Python for the CV project.

  15. 75 FR 72863 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2010-11-26

    ... a Class A Commercial Driver's License (CDL) from Virginia. His driving record for the last 3 years... last 3 years shows no crashes and no convictions for moving violations in a CMV. Ronnie E. Henderson Mr. Henderson, 64, has had loss of vision in his left eye since 2007. The best corrected visual acuity in his...

  16. 76 FR 37883 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2011-06-28

    ... your comments, please include a self-addressed, stamped envelope or postcard or print the..., including amblyopia, complete loss of vision, no light perception, cataract, central retinal atrophy...). Other studies demonstrated theories of predicting crash proneness from crash history coupled with other...

  17. Modern permanent magnetic materials - preparation and properties

    International Nuclear Information System (INIS)

    Rodewald, W.

    1989-01-01

    First of all, the basic properties of the classical (steel, AlNiCo) permanent magnetic materials and the modern rare-earth (RE) permanent magnetic materials are compared. Since the properties of RE permanent magnets depend on the particular production process, the fundamentals of the main industrial processes (powder metallurgy, rapid-solidification technique) are described and the typical properties are explained. Furthermore the production processes in development such as mechanical alloying, melt spinning technique and extrusion upsetting are briefly outlined. For applying the permanent magnets, they have to be completely magnetized. The magnetization behaviour of the various RE permanent magnets is discussed by means of the internal demagnetization curve. Finally the various influences on the temperature stability of RE permanent magnets are compiled. (orig./MM) [de

  18. Restoration of vision after transplantation of photoreceptors.

    Science.gov (United States)

    Pearson, R A; Barber, A C; Rizzi, M; Hippert, C; Xue, T; West, E L; Duran, Y; Smith, A J; Chuang, J Z; Azam, S A; Luhmann, U F O; Benucci, A; Sung, C H; Bainbridge, J W; Carandini, M; Yau, K-W; Sowden, J C; Ali, R R

    2012-05-03

    Cell transplantation is a potential strategy for treating blindness caused by the loss of photoreceptors. Although transplanted rod-precursor cells are able to migrate into the adult retina and differentiate to acquire the specialized morphological features of mature photoreceptor cells, the fundamental question remains whether transplantation of photoreceptor cells can actually improve vision. Here we provide evidence of functional rod-mediated vision after photoreceptor transplantation in adult Gnat1−/− mice, which lack rod function and are a model of congenital stationary night blindness. We show that transplanted rod precursors form classic triad synaptic connections with second-order bipolar and horizontal cells in the recipient retina. The newly integrated photoreceptor cells are light-responsive with dim-flash kinetics similar to adult wild-type photoreceptors. By using intrinsic imaging under scotopic conditions we demonstrate that visual signals generated by transplanted rods are projected to higher visual areas, including V1. Moreover, these cells are capable of driving optokinetic head tracking and visually guided behaviour in the Gnat1−/− mouse under scotopic conditions. Together, these results demonstrate the feasibility of photoreceptor transplantation as a therapeutic strategy for restoring vision after retinal degeneration.

  19. Intrusive luxation of 60 permanent incisors

    DEFF Research Database (Denmark)

    Tsilingaridis, Georgios; Malmgren, Barbro; Andreasen, Jens O

    2012-01-01

      Intrusive luxation in the permanent dentition is an uncommon injury but it is considered one of the most severe types of dental trauma because of the risk for damage to the periodontal ligament, pulp and alveolar bone. Management of intrusive luxation in the permanent dentition is controversial....... The purpose of this study was to evaluate pulp survival and periodontal healing in intrusive luxated permanent teeth in relation to treatment alternatives, degree of intrusion and root development....

  20. Corrosion behaviour of Nd-Fe-B permanent magnets

    International Nuclear Information System (INIS)

    Mummert, K.; El-Aziz, A.M.; Barkleit, G.; Schultz, L.; Rodewald, W.

    2000-01-01

    The corrosion behaviour of Nd-Fe-B permanent magnetic alloys as well as of single phases of these alloys have been investigated in sulphuric acid at room temperature and humid air at 150 C using mass loss and electrochemical techniques. Scanning electron microscopy and scanning probe microscopy were used to study the surface topography. The electrostatic surface potential was examined by scanning probe microscopy using tapping mode. A correlation between the electrostatic surface potential and the corrosion rate of these alloys was found. The higher the value of the electrostatic surface potential of the intergranular phases the higher is the corrosion sensitivity. The strength of the corrosion attack on the phases of sintered permanent magnetic alloys is as follows: Ferromagnetic phase < B-rich phase < Nd-rich phase. The differences in the chemical composition as well as in the preparation of these magnetic alloys have distinct influence on the corrosion resistance of the magnetic Nd-Fe-B alloys. (orig.)

  1. The Permanently Shadowed Regions of Dwarf Planet Ceres

    Science.gov (United States)

    Schorghofer, Norbert; Mazarico, Erwan; Platz, Thomas; Preusker, Frank; Schroeder, Stefan E.; Raymond, Carol A.; Russell, Christopher T.

    2016-01-01

    Ceres has only a small spin axis tilt (4 deg), and craters near its rotational poles can experience permanent shadow and trap volatiles, as is the case on Mercury and on Earth's Moon. Topography derived from stereo imaging by the Dawn spacecraft is used to calculate direct solar irradiance that defines the extent of the permanently shadowed regions (PSRs). In the northern polar region, PSRs cover approximately 1800 sq km or 0.13% of the hemisphere, and most of the PSRs are cold enough to trap water ice over geological time periods. Based on modeling of the water exosphere, water molecules seasonally reside around the winter pole and ultimately an estimated 0.14% of molecules get trapped. Even for the lowest estimates of the amount of available water, this predicts accumulation rates in excess of loss rates, and hence, there should be fresh ice deposits in the cold traps.

  2. Grain Refinement of Permanent Mold Cast Copper Base Alloys

    Energy Technology Data Exchange (ETDEWEB)

    M.Sadayappan; J.P.Thomson; M.Elboujdaini; G.Ping Gu; M. Sahoo

    2005-04-01

    Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.

  3. Visions of Alternative (Unpredictable Futures and Their Use in Policy Analysis

    Directory of Open Access Journals (Sweden)

    Robert Costanza

    2000-07-01

    Full Text Available The most critical task facing humanity today is the creation of a shared vision of a sustainable and desirable society, one that can provide permanent prosperity within the biophysical constraints of the real world in a way that is fair and equitable to all of humanity, to other species, and to future generations. Recent work with businesses and communities indicates that creating a shared vision is the most effective engine for change in the desired direction, yet most effort in "futures modeling" has focused on extrapolating past trends rather than envisioning alternative futures. Science and economics as applied to policy are in conflict more often over alternative visions of the world than purely "scientific" disagreements. Likewise, governance has gotten bogged down in mediating short term conflicts between special interests rather than its more basic role of creating broadly shared visions that can guide dispute resolution. This paper addresses the question of what policies are most appropriate for society now, given alternative visions of the future and the enormous uncertainty about the reality of the assumptions underlying these visions. Four specific visions are laid out as being representative of the major alternatives. For each vision the benefits of achieving the vision, the assumptions that would have to be true in order for it to be achieved, and the implications of it being attempted but not achieved are explored. It is argued that dealing with uncertainty about the nature of the world, its carrying capacity for humans, the impacts of climate change, and other aspects of its future can best be done at this level of future visions and assumptions, not at more detailed levels (like the parameter uncertainty in models. Application of this vision/uncertainty analysis can help us both to design the future society we want and to maximize the chances of our getting there safely.

  4. The handicap of abnormal colour vision.

    Science.gov (United States)

    Cole, Barry L

    2004-07-01

    All people with abnormal colour vision, except for a few mildly affected deuteranomals, report that they experience problems with colour in everyday life and at work. Contemporary society presents them with increasing problems because colour is now so widely used in printed materials and in computer displays. Equal opportunity law gives them protection against unfair discrimination in employment, so a decision to exclude a person from employment on the grounds of abnormal colour vision must now be well supported by good evidence and sound argument. This paper reviews the investigations that have contributed to understanding the nature and consequences of the problems they have. All those with abnormal colour vision are at a disadvantage with comparative colour tasks that involve precise matching of colours or discrimination of fine colour differences either because of their loss of colour discrimination or anomalous perception of metamers. The majority have problems when colour is used to code information, in man-made colour codes and in naturally occurring colour codes that signal ripeness of fruit, freshness of meat or illness. They can be denied the benefit of colour to mark out objects and organise complex visual displays. They may be unreliable when a colour name is used as an identifier. They are slower and less successful in search when colour is an attribute of the target object or is used to organise the visual display. Because those with the more severe forms of abnormal colour vision perceive a very limited gamut of colours, they are at a disadvantage in the pursuit and appreciation of those forms of art that use colour.

  5. Colour Vision Impairment in Young Alcohol Consumers.

    Directory of Open Access Journals (Sweden)

    Alódia Brasil

    Full Text Available Alcohol consumption among young adults is widely accepted in modern society and may be the starting point for abusive use of alcohol at later stages of life. Chronic alcohol exposure can lead to visual function impairment. In the present study, we investigated the spatial luminance contrast sensitivity, colour arrangement ability, and colour discrimination thresholds on young adults that weekly consume alcoholic beverages without clinical concerns. Twenty-four young adults were evaluated by an ophthalmologist and performed three psychophysical tests to evaluate their vision functions. We estimated the spatial luminance contrast sensitivity function at 11 spatial frequencies ranging from 0.1 to 30 cycles/degree. No difference in contrast sensitivity was observed comparing alcohol consumers and control subjects. For the evaluation of colour vision, we used the Farnsworth-Munsell 100 hue test (FM 100 test to test subject's ability to perform a colour arrangement task and the Mollon-Reffin test (MR test to measure subject's colour discrimination thresholds. Alcohol consumers made more mistakes than controls in the FM100 test, and their mistakes were diffusely distributed in the FM colour space without any colour axis preference. Alcohol consumers also performed worse than controls in the MR test and had higher colour discrimination thresholds compared to controls around three different reference points of a perceptually homogeneous colour space, the CIE 1976 chromaticity diagram. There was no colour axis preference in the threshold elevation observed among alcoholic subjects. Young adult weekly alcohol consumers showed subclinical colour vision losses with preservation of spatial luminance contrast sensitivity. Adolescence and young adult age are periods of important neurological development and alcohol exposure during this period of life might be responsible for deficits in visual functions, especially colour vision that is very sensitive to

  6. Understanding and applying machine vision

    CERN Document Server

    Zeuch, Nello

    2000-01-01

    A discussion of applications of machine vision technology in the semiconductor, electronic, automotive, wood, food, pharmaceutical, printing, and container industries. It describes systems that enable projects to move forward swiftly and efficiently, and focuses on the nuances of the engineering and system integration of machine vision technology.

  7. Management Matters. Nurture Your Vision

    Science.gov (United States)

    Pappas, Marjorie L.

    2005-01-01

    In many professional roles, long-term vision may help guide short-term decisions. This is especially true for school library professionals as library media programs are constantly evolving. This author suggests strategies to assist library media specialists to nurture their vision and provides reviews of several sources and experts in the field…

  8. Eldercare at Home: Vision Problems

    Science.gov (United States)

    ... seeing close objects or reading small print. Many things can be done to help with these vision problems. Using reading ... t Working If vision problems seem to be getting worse and are of major concern to the ... what the results have been. Related Resources ...

  9. Visual rehabilitation: visual scanning, multisensory stimulation and vision restoration trainings

    Directory of Open Access Journals (Sweden)

    Neil M. Dundon

    2015-07-01

    Full Text Available Neuropsychological training methods of visual rehabilitation for homonymous vision loss caused by postchiasmatic damage fall into two fundamental paradigms: compensation and restoration. Existing methods can be classified into three groups: Visual Scanning Training (VST, Audio-Visual Scanning Training (AViST and Vision Restoration Training (VRT. VST and AViST aim at compensating vision loss by training eye scanning movements, whereas VRT aims at improving lost vision by activating residual visual functions by training light detection and discrimination of visual stimuli. This review discusses the rationale underlying these paradigms and summarizes the available evidence with respect to treatment efficacy. The issues raised in our review should help guide clinical care and stimulate new ideas for future research uncovering the underlying neural correlates of the different treatment paradigms. We propose that both local within-system interactions (i.e., relying on plasticity within peri-lesional spared tissue and changes in more global between-system networks (i.e., recruiting alternative visual pathways contribute to both vision restoration and compensatory rehabilitation that ultimately have implications for the rehabilitation of cognitive functions.

  10. Prevalence of color vision deficiency among arc welders.

    Science.gov (United States)

    Heydarian, Samira; Mahjoob, Monireh; Gholami, Ahmad; Veysi, Sajjad; Mohammadi, Morteza

    This study was performed to investigate whether occupationally related color vision deficiency can occur from welding. A total of 50 male welders, who had been working as welders for at least 4 years, were randomly selected as case group, and 50 age matched non-welder men, who lived in the same area, were regarded as control group. Color vision was assessed using the Lanthony desatured panel D-15 test. The test was performed under the daylight fluorescent lamp with a spectral distribution of energy with a color temperature of 6500K and a color rendering index of 94 that provided 1000lx on the work plane. The test was carried out monocularly and no time limit was imposed. All data analysis were performed using SPSS, version 22. The prevalence of dyschromatopsia among welders was 15% which was statistically higher than that of nonwelder group (2%) (p=0.001). Among welders with dyschromatopsia, color vision deficiency in 72.7% of cases was monocular. There was positive relationship between the employment length and color vision loss (p=0.04). Similarly, a significant correlation was found between the prevalence of color vision deficiency and average working hours of welding a day (p=0.025). Chronic exposure to welding light may cause color vision deficiency. The damage depends on the exposure duration and the length of their employment as welders. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  11. IPPF's strategic vision 2000.

    Science.gov (United States)

    Mahler, H

    1994-09-01

    The International Planned Parenthood Federation (IPPF) supports the objectives of the International Conference on Population and Development. The draft conference document displays the linkages between women's rights, poverty, population, and sustainable development. In the next two to three decades the global population will grow by a staggering 50% and that reality requires sustained socioeconomic growth. The 6 components of IPPF's Strategic Vision 2000 and the action agenda for meeting these challenges are as follows: 1) The small family is rapidly becoming the cultural norm everywhere, as more than 60% of all fertile women and men are using safe and effective contraceptive methods. 2) Sexual and reproductive health is becoming an integral part of the physical, mental, and social health culture and not just the absence of pregnancy, disease or injury. The members of IPPF have been developing programs concentrating on adolescent sexuality. IPPF is also concerned about HIV, AIDS and sexually transmitted diseases as they relate to the work undertaken by family planning associations. 3) The quality of care has been heightened by the right of informed choice, service sustainability, and the maintenance of the highest standards. 4) Vigorous programs are in place to eliminate unsafe abortion and to increase access to safe abortion. 5) Young people are systematically supported to give voice to the need for understanding their sexuality and services. There are currently more than 500 million young women and men between the ages of 15 and 19, and their numbers increase for a long time to come. 6) Women are fast moving towards full participation in all aspects of local and global development demanding reproductive rights. IPPF and its associations, through Vision 2000, are committed to the objective of sexual and reproductive health at the national and international levels.

  12. 2020 Vision Project Summary

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, K.W.; Scott, K.P.

    2000-11-01

    Since the 2020 Vision project began in 1996, students from participating schools have completed and submitted a variety of scenarios describing potential world and regional conditions in the year 2020 and their possible effect on US national security. This report summarizes the students' views and describes trends observed over the course of the 2020 Vision project's five years. It also highlights the main organizational features of the project. An analysis of thematic trends among the scenarios showed interesting shifts in students' thinking, particularly in their views of computer technology, US relations with China, and globalization. In 1996, most students perceived computer technology as highly beneficial to society, but as the year 2000 approached, this technology was viewed with fear and suspicion, even personified as a malicious, uncontrollable being. Yet, after New Year's passed with little disruption, students generally again perceived computer technology as beneficial. Also in 1996, students tended to see US relations with China as potentially positive, with economic interaction proving favorable to both countries. By 2000, this view had transformed into a perception of China emerging as the US' main rival and ''enemy'' in the global geopolitical realm. Regarding globalization, students in the first two years of the project tended to perceive world events as dependent on US action. However, by the end of the project, they saw the US as having little control over world events and therefore, we Americans would need to cooperate and compromise with other nations in order to maintain our own well-being.

  13. Functional programming for computer vision

    Science.gov (United States)

    Breuel, Thomas M.

    1992-04-01

    Functional programming is a style of programming that avoids the use of side effects (like assignment) and uses functions as first class data objects. Compared with imperative programs, functional programs can be parallelized better, and provide better encapsulation, type checking, and abstractions. This is important for building and integrating large vision software systems. In the past, efficiency has been an obstacle to the application of functional programming techniques in computationally intensive areas such as computer vision. We discuss and evaluate several 'functional' data structures for representing efficiently data structures and objects common in computer vision. In particular, we will address: automatic storage allocation and reclamation issues; abstraction of control structures; efficient sequential update of large data structures; representing images as functions; and object-oriented programming. Our experience suggests that functional techniques are feasible for high- performance vision systems, and that a functional approach simplifies the implementation and integration of vision systems greatly. Examples in C++ and SML are given.

  14. Computer vision for an autonomous mobile robot

    CSIR Research Space (South Africa)

    Withey, Daniel J

    2015-10-01

    Full Text Available Computer vision systems are essential for practical, autonomous, mobile robots – machines that employ artificial intelligence and control their own motion within an environment. As with biological systems, computer vision systems include the vision...

  15. Plaque Brachytherapy for Uveal Melanoma: A Vision Prognostication Model

    International Nuclear Information System (INIS)

    Khan, Niloufer; Khan, Mohammad K.; Bena, James; Macklis, Roger; Singh, Arun D.

    2012-01-01

    Purpose: To generate a vision prognostication model after plaque brachytherapy for uveal melanoma. Methods and Materials: All patients with primary single ciliary body or choroidal melanoma treated with iodine-125 or ruthenium-106 plaque brachytherapy between January 1, 2005, and June 30, 2010, were included. The primary endpoint was loss of visual acuity. Only patients with initial visual acuity better than or equal to 20/50 were used to evaluate visual acuity worse than 20/50 at the end of the study, and only patients with initial visual acuity better than or equal to 20/200 were used to evaluate visual acuity worse than 20/200 at the end of the study. Factors analyzed were sex, age, cataracts, diabetes, tumor size (basal dimension and apical height), tumor location, and radiation dose to the tumor apex, fovea, and optic disc. Univariate and multivariable Cox proportional hazards were used to determine the influence of baseline patient factors on vision loss. Kaplan-Meier curves (log rank analysis) were used to estimate freedom from vision loss. Results: Of 189 patients, 92% (174) were alive as of February 1, 2011. At presentation, visual acuity was better than or equal to 20/50 and better than or equal to 20/200 in 108 and 173 patients, respectively. Of these patients, 44.4% (48) had post-treatment visual acuity of worse than 20/50 and 25.4% (44) had post-treatment visual acuity worse than 20/200. By multivariable analysis, increased age (hazard ratio [HR] of 1.01 [1.00-1.03], P=.05), increase in tumor height (HR of 1.35 [1.22-1.48], P<.001), and a greater total dose to the fovea (HR of 1.01 [1.00-1.01], P<.001) were predictive of vision loss. This information was used to develop a nomogram predictive of vision loss. Conclusions: By providing a means to predict vision loss at 3 years after treatment, our vision prognostication model can be an important tool for patient selection and treatment counseling.

  16. Plaque Brachytherapy for Uveal Melanoma: A Vision Prognostication Model

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Niloufer [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States); Khan, Mohammad K. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, Georgia (United States); Bena, James [Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio (United States); Macklis, Roger [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States); Singh, Arun D., E-mail: singha@ccf.org [Department of Ophthalmic Oncology, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (United States)

    2012-11-01

    Purpose: To generate a vision prognostication model after plaque brachytherapy for uveal melanoma. Methods and Materials: All patients with primary single ciliary body or choroidal melanoma treated with iodine-125 or ruthenium-106 plaque brachytherapy between January 1, 2005, and June 30, 2010, were included. The primary endpoint was loss of visual acuity. Only patients with initial visual acuity better than or equal to 20/50 were used to evaluate visual acuity worse than 20/50 at the end of the study, and only patients with initial visual acuity better than or equal to 20/200 were used to evaluate visual acuity worse than 20/200 at the end of the study. Factors analyzed were sex, age, cataracts, diabetes, tumor size (basal dimension and apical height), tumor location, and radiation dose to the tumor apex, fovea, and optic disc. Univariate and multivariable Cox proportional hazards were used to determine the influence of baseline patient factors on vision loss. Kaplan-Meier curves (log rank analysis) were used to estimate freedom from vision loss. Results: Of 189 patients, 92% (174) were alive as of February 1, 2011. At presentation, visual acuity was better than or equal to 20/50 and better than or equal to 20/200 in 108 and 173 patients, respectively. Of these patients, 44.4% (48) had post-treatment visual acuity of worse than 20/50 and 25.4% (44) had post-treatment visual acuity worse than 20/200. By multivariable analysis, increased age (hazard ratio [HR] of 1.01 [1.00-1.03], P=.05), increase in tumor height (HR of 1.35 [1.22-1.48], P<.001), and a greater total dose to the fovea (HR of 1.01 [1.00-1.01], P<.001) were predictive of vision loss. This information was used to develop a nomogram predictive of vision loss. Conclusions: By providing a means to predict vision loss at 3 years after treatment, our vision prognostication model can be an important tool for patient selection and treatment counseling.

  17. Image enhancement filters significantly improve reading performance for low vision observers

    Science.gov (United States)

    Lawton, T. B.

    1992-01-01

    As people age, so do their photoreceptors; many photoreceptors in central vision stop functioning when a person reaches their late sixties or early seventies. Low vision observers with losses in central vision, those with age-related maculopathies, were studied. Low vision observers no longer see high spatial frequencies, being unable to resolve fine edge detail. We developed image enhancement filters to compensate for the low vision observer's losses in contrast sensitivity to intermediate and high spatial frequencies. The filters work by boosting the amplitude of the less visible intermediate spatial frequencies. The lower spatial frequencies. These image enhancement filters not only reduce the magnification needed for reading by up to 70 percent, but they also increase the observer's reading speed by 2-4 times. A summary of this research is presented.

  18. A Sudden Total Loss of Vision After Routine Cataract Surgery ...

    African Journals Online (AJOL)

    We share our experience of a 50-year-old controlled hypertensive woman who had routine cataract surgery in her left eye. She was given retrobulbar Xylocaine with adrenalin and postoperative gentamycin. She subsequently became blind in the operated eye after developing macular infarction by the first day post ...

  19. Key informant perceptions of vision loss in children and implications ...

    African Journals Online (AJOL)

    Materials and Methods: A population-based study on the prevalence and causes of childhood blindness and severe visual impairment was conducted using the KI method. KIs were selected by their communities and trained in advocacy, identifi cation and referral of children with visual impairment. Prior to the KI training, ...

  20. Bilateral vision loss in a captive cheetah (Acinonyx jubatus).

    Science.gov (United States)

    Walser-Reinhardt, Ladina; Wernick, Morena B; Hatt, Jean-Michel; Spiess, Bernhard M

    2010-09-01

    The following case report describes a 1-year-old female cheetah (Acinonyx jubatus) with bilateral blindness and unresponsive pupils. For comparison, a second healthy 2.5-year-old male cheetah without visual deficits was also examined. Clinical examination of both animals included biomicroscopy, indirect ophthalmoscopy, tonometry, and electroretinography. The young female cheetah showed no menace response, no direct or indirect pupillary light reflex, and no dazzle reflex in either eye. Fundus lesions, as detected by indirect ophthalmoscopy, are described for the female animal. In both eyes, the fundus color was green/turquoise/yellow with multiple hyperpigmented linear lesions in the tapetal area around the optic nerve. The optic nerve head was dark gray and about half the normal size suggesting bilateral optic nerve hypoplasia and retinal dysplasia or differentially optic nerve atrophy and chorioretinal scarring. The ERG had low amplitudes in the right eye but appeared normal in the left eye compared with the male cheetah. Blood levels did not suggest current taurine deficiency. This is addressed to some degree in the discussion. Bilateral optic nerve hypoplasia or optic nerve atrophy is a rare anomaly in cats and has not yet been described in a cheetah.

  1. Helping a Loved One (Who Has Vision Loss)

    Science.gov (United States)

    ... NEI Intranet (Employees Only) *PDF files require the free Adobe® Reader® software for viewing. This website is maintained by the NEI Office of Science Communications, Public Liaison, and Education. Technical questions about this website can be addressed ...

  2. Considering the Influence of Nonadaptive Evolution on Primate Color Vision.

    Directory of Open Access Journals (Sweden)

    Rachel L Jacobs

    Full Text Available Color vision in primates is variable across species, and it represents a rare trait in which the genetic mechanisms underlying phenotypic variation are fairly well-understood. Research on primate color vision has largely focused on adaptive explanations for observed variation, but it remains unclear why some species have trichromatic or polymorphic color vision while others are red-green color blind. Lemurs, in particular, are highly variable. While some species are polymorphic, many closely-related species are strictly dichromatic. We provide the first characterization of color vision in a wild population of red-bellied lemurs (Eulemur rubriventer, Ranomafana National Park, Madagascar with a sample size (87 individuals; NX chromosomes = 134 large enough to detect even rare variants (0.95 probability of detection at ≥ 3% frequency. By sequencing exon 5 of the X-linked opsin gene we identified opsin spectral sensitivity based on known diagnostic sites and found this population to be dichromatic and monomorphic for a long wavelength allele. Apparent fixation of this long allele is in contrast to previously published accounts of Eulemur species, which exhibit either polymorphic color vision or only the medium wavelength opsin. This unexpected result may represent loss of color vision variation, which could occur through selective processes and/or genetic drift (e.g., genetic bottleneck. To indirectly assess the latter scenario, we genotyped 55 adult red-bellied lemurs at seven variable microsatellite loci and used heterozygosity excess and M-ratio tests to assess if this population may have experienced a recent genetic bottleneck. Results of heterozygosity excess but not M-ratio tests suggest a bottleneck might have occurred in this red-bellied lemur population. Therefore, while selection may also play a role, the unique color vision observed in this population might have been influenced by a recent genetic bottleneck. These results emphasize the

  3. The role of peripheral vision in saccade planning: learning from people with tunnel vision.

    Science.gov (United States)

    Luo, Gang; Vargas-Martin, Fernando; Peli, Eli

    2008-12-22

    Both visually salient and top-down information are important in eye movement control, but their relative roles in the planning of daily saccades are unclear. We investigated the effect of peripheral vision loss on saccadic behaviors in patients with tunnel vision (visual field diameters 7 degrees-16 degrees) in visual search and real-world walking experiments. The patients made up to two saccades per second to their pre-saccadic blind areas, about half of which had no overlap between the post- and pre-saccadic views. In the visual search experiment, visual field size and the background (blank or picture) did not affect the saccade sizes and direction of patients (n = 9). In the walking experiment, the patients (n = 5) and normal controls (n = 3) had similar distributions of saccade sizes and directions. These findings might provide a clue about the large extent of the top-down mechanism influence on eye movement control.

  4. Corporate Policies with Permanent and Transitory Shocks

    NARCIS (Netherlands)

    J-P. Decamps (Jean-Paul); S. Gryglewicz (Sebastian); E. Morellec (Erwan); S. Villeneuve (Stephane)

    2016-01-01

    textabstractWe model the financing, cash holdings, and hedging policies of a firm facing financing frictions and subject to permanent and transitory cash flow shocks. We show that permanent and transitory shocks generate distinct, sometimes opposite, effects on corporate policies and use the model

  5. OAS :: Authorities : Permanent Representatives to the OAS

    Science.gov (United States)

    Rights Actions against Corruption C Children Civil Registry Civil Society Contact Us Culture Cyber Representative of Belize Diego Pary Rodríguez Bolivia Diego Pary Rodríguez Ambassador, Permanent Representative of Bolivia José Luiz Machado Brazil José Luiz Machado e Costa Ambassador, Permanent Representative

  6. Leadership in a (permanent) crisis.

    Science.gov (United States)

    Heifetz, Ronald; Grashow, Alexander; Linsky, Marty

    2009-01-01

    The current economic crisis is not just another rough spell. Today's mix of urgency, high stakes, and uncertainty will continue even after the recession ends. The immediate crisis--which we will get through with policy makers' expert technical adjustments--sets the stage for a sustained, or even permanent, crisis, a relentless series of challenges no one has encountered before. Instead of hunkering down and relying on their familiar expertise to deal with the sustained crisis, people in positions of authority--whether they are CEOs or managers heading up a company initiative--must practice what the authors call adaptive leadership. They must, of course, tackle the underlying causes of the crisis, but they must also simultaneously make the changes that will allow their organizations to thrive in turbulent environments. Adaptive leadership is an improvisational and experimental art, requiring some new practices. Like Julie Gilbert, who overcame internal resistance to reorient Best Buy toward female purchasers, adaptive leaders get things done to meet today's challenges and then modify those things to thrive in tomorrow's world. They also embrace disequilibrium, using turbulence as an opportunity to build crucial new capacities, as Paul Levy did to rescue Beth Israel Deaconess Medical Center from a profound financial crisis. Finally, adaptive leaders, such as Egon Zehnder, the founder of an executive search firm, draw out the leadership skills that reside deep in the organization, recognizing the interdependence of all employees and mobilizing everyone to generate solutions.

  7. Guidelines for removing permanent makeup

    Directory of Open Access Journals (Sweden)

    C.Bettina Rümmelein

    2016-09-01

    Full Text Available Permanent makeup (PMU is a frequently implemented cosmetic procedure performed by beauticians. From a technical point, PMU is considered a facial tattoo. Failed procedures or a change of mind can lead to the desire for removal. The purpose of this retrospective evaluation of patients who came to the clinic with the desire to remove PMU between 2011 and 2015 was to explore the problems, side effects, and results in order to define treatment guidelines for other doctors. We evaluated 87 individual cases in total. In treatable cases, i.e. 52 out of the 87 cases, laser treatments were performed using a nanosecond Q-switched neodymium-doped yttrium aluminium garnet (Nd:YAG laser. It takes between 1-12 treatments to remove the PMU. In three cases, the colour of the PMU could not be removed by laser and remained after the treatment. In two cases, laser treatment had to be terminated due to colour changes towards the green-blue spectrum. Before PMU removal, laser test shots are urgently recommended as unforeseeable colour changes can cause severe aesthetically unpleasant results. Covered up PMU (skin colour is particularly susceptible to changes in colour. Heat-induced shrinking of the eye area can cause an ectropium. Surgical solutions also have to be taken into consideration. The use of proper eye protection with intraocular eye shields is mandatory. This article is an attempt to set up some guidelines for the treatment of PMU removal.

  8. Two dimensional model of a permanent magnet spur gear

    DEFF Research Database (Denmark)

    Jørgensen, Frank Thorleif; Andersen, Torben Ole; Rasmussen, Peter Omand

    2005-01-01

    This paper presents calculation and measurement results of a high-performance permanent-magnetic gear. The analyzed permanent-magnetic gear has a gear ratio of 5.5 and is able to deliver 27 N/spl middot/m. The analysis has shown that special attention needs to be paid to the system where the gear...... is to be installed because of a low natural torsion spring constant. The analyzed gear was also constructed in practice in order to validate the analysis and predict the efficiency. The measured torque from the magnetic gear was only 16 N/spl middot/m reduced by the large end-effects. A systematic analysis...... of the loss components in the magnetic gear is also performed in order to figure out why the efficiency for the actual construction was only 81%. A large magnetic loss component originated in the bearings, where an unplanned extra bearing was necessary due to mechanical problems. Without the losses...

  9. Quality of life after permanent prostate implant

    International Nuclear Information System (INIS)

    Arterbery, V. Elayne; Frazier, Arthur; Dalmia, Praveen; Porter, Arthur

    1997-01-01

    Purpose: To report on the quality of life in patients who have received a permanent transperineal ultrasound guide prostate implant. There is increasing recognition that prostate cancer therapy impacts significantly on the patients ability to pursue relational, occupational and social interests. With the substantially expanded patient role in directing treatment for prostate cancer, the importance of examining quality of life outcomes in addition to survival has been underscored. Materials and Methods: 51 sequential patients with clinically localized prostate cancer who underwent permanent prostate implantation from September 1995 to October 1996 were evaluated. All patients were clinically staged as T1c or T2a and received implant with Iodine 125 or Palladium 103 as definitive treatment. Data was collected using the EORTC genitourinary group questionnaire and supplemental questions during an interview. Results: Urinary symptoms such as nocturia, frequency and dysuria were the most pronounced in the first two months after implant and then decreased in the majority of patients. The EORTC questionnaire was administered at 6 months and examined urinary quality, sexual quality and perception of symptoms. With regard to urinary quality, 17% had mild dysuria at 6 months and 40% noted that they urinated more frequently than pre implant. No patient had hematuria and 0 % were incontinent. 3% stated that they had occasional loss of minimal urine with severe urgency. Only 2% required intermittent self catheterization after implant secondary to obstructive symptoms. Over 90% were on an alpha blocker post implant for a minimum of 6 weeks. 0% reported psychological distress and 3% noted a disruption in social or family life. 15% experienced some fatigue and 10% noted a decreased functional status but only 1% a decreased role function. Additional questions addressed lifestyle and work issues. 100% would have an implant again as definitive treatment and 98% would recommend the

  10. Motor Integrated Permanent Magnet Gear in a Battery Electrical Vehicle

    DEFF Research Database (Denmark)

    Frandsen, Tommy; Mathe, Laszlo; Berg, Nick Ilsø

    2015-01-01

    This paper presents the physical construction and test results of two new demonstrators of a Motor Integrated Permanent Magnet Gear (MIPMG), which is a second version of an already tested demonstrator. The demonstrators will be used as traction units for a Battery Electrical Vehicle (BEV......) and the background for the specifications are elaborated. Simulated as well as measured results of rotational losses of the first and second version are compared. The efficiency of the new design is investigated and compared to three direct drive motors in a few operating points and the MIPMG v.2 seems superior when...

  11. Axial Permanent Magnet Generator for Wearable Energy Harvesting

    DEFF Research Database (Denmark)

    Högberg, Stig; Sødahl, Jakob Wagner; Mijatovic, Nenad

    2016-01-01

    An increasing demand for battery-free electronics is evident by the rapid increase of wearable devices, and the design of wearable energy harvesters follows accordingly. An axial permanent magnet generator was designed to harvest energy from human body motion and supplying it to a wearable......W, respectively) with an iron yoke is subject to losses that exceed the realistic input power, and was therefore deemed infeasible. A generator without the iron yoke was concluded to perform well as a wearable energy harvester. An experimental investigation of a prototype revealed an output power of almost 1 m...

  12. Idiopathic multifocal choroiditis/punctate inner choroidopathy with acute photoreceptor loss or dysfunction out of proportion to clinically visible lesions

    Science.gov (United States)

    Munk, Marion R.; Jung, Jesse J.; Biggee, Kristin; Tucker, William R.; Sen, H. Nida; Schmidt-Erfurth, Ursula; Fawzi, Amani A.; Jampol, Lee M.

    2014-01-01

    Purpose To report acute/subacute vision loss and paracentral scotomata in patients with idiopathic multifocal choroiditis/punctate inner choroidopathy (MFC/PIC) due to large zones of acute photoreceptor attenuation surrounding the chorioretinal lesions. Methods Multimodal-imaging case-series Results Six females and 2 males were included (mean age 31.5±5.8 years). Vision ranged from 20/20-1 to hand motion (mean 20/364). SD-OCT demonstrated extensive attenuation of the external limiting membrane (ELM), ellipsoid and interdigitation zones, adjacent to the visible MFC/PIC lesions. The corresponding areas were hyperautofluorescent on fundus-autofluorescence (FAF), and were associated with corresponding visual field defects. Full-field ERG (available in 3 cases) showed markedly decreased cone/rod response and multifocal ERG revealed reduced amplitudes and increased implicit times in 2 cases. Three patients received no treatment, the remaining were treated with oral corticosteroids (n=4), oral acyclovir/valacyclovir (n=2), intravitreal/posterior subtenon triamcinolone-acetate (n=3) and anti-VEGF (n=2). Visual recovery occurred in only 3 cases, of whom 2 were treated. Varying morphological recovery was found in 6 cases, associated with decrease in hyperautofluorescence on FAF. Conclusions MFC/PIC can present with transient or permanent central photoreceptor attenuation/loss. This presentation is likely a variant of MFC/PIC with chorioretinal atrophy. Associated changes are best evaluated using multimodal imaging. PMID:25322466

  13. National Hydrogen Vision Meeting Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    None

    2001-11-01

    This document provides presentations and summaries of the notes from the National Hydrogen Vision Meeting''s facilitated breakout sessions. The Vision Meeting, which took place November 15-16, 2001, kicked off the public-private partnership that will pave the way to a more secure and cleaner energy future for America. These proceedings were compiled into a formal report, A National Vision of America''s Transition to a Hydrogen Economy - To 2030 and Beyond, which is also available online.

  14. Causes of permanent childhood hearing impairment.

    Science.gov (United States)

    Korver, Anna M H; Admiraal, Ronald J C; Kant, Sarina G; Dekker, Friedo W; Wever, Capi C; Kunst, Henricus P M; Frijns, Johan H M; Oudesluys-Murphy, Anne Marie

    2011-02-01

    The causes of Permanent Childhood Hearing Impairment (PCHI) are often quoted as being hereditary in 50%, acquired in 25%, and unknown in 25% of cases. Interest in the causes of PCHI has grown recently due to increasing diagnostic possibilities. We investigated the evidence for the reported distribution of these causes. Population-based study and a systematic review. Inclusion criteria for population-based study: children born between 2003 and 2005, resident in The Netherlands at birth, known at an Audiology Center with PCHI at the age of 3-5 years. The causes of PCHI were determined prospectively by detection of congenital cytomegalovirus on dried blood spots and/or genetic diagnostic investigations in addition to reviewing data from medical records. A systematic review was carried out using three terms (hearing loss, infant, and etiology) and limited to articles published between January 1997 and July 2009. Main outcome measures were: the (weighted) proportions of the various causes of PCHI following diagnostic investigations. In the study-population (n = 185) a hereditary cause was found in 38.9%, acquired cause in 29.7%, miscellaneous cause in 7.1%, and the cause remained unknown in 24.3%. The systematic review of the literature (n = 9 articles) resulted in a weighted mean of 30.4% hereditary, 19.2% acquired, and 48.3% unknown causes of PCHI. The systematic review and the results of the population-based study provided little support for the generally accepted distribution of causes of PCHI. Copyright © 2010 The American Laryngological, Rhinological, and Otological Society, Inc.

  15. 2020 vision for KAUST

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Felicitas Pauss, Head of International Relations at CERN, greets Members of the Board of Trustees of the King Abdullah University of Science and Technology, KAUST, who visited CERN on Friday 6 August.   Members of Board of Trustees of the King Abdullah University of Science and Technology upon their arrival at CERN. KAUST, which is situated on Saudi Arabia’s Red Sea coast, is a new, forward-looking co-educational and research university with a vision to become one of the world’s top ten science and technology Universities by 2020, stimulating the intellectual life of Saudi Arabia and making significant contributions to the country’s economy. CERN’s Director General, Rolf Heuer, is a member of the Board of Trustees. “I accepted the invitation to join the board because I believe that KAUST’s values can make a real difference to the region and to the world,” he said. The University’s mission statement emphasises achiev...

  16. Visiones de la etnicidad

    Directory of Open Access Journals (Sweden)

    MANUEL ÁNGEL RÍO RUIZ

    2002-01-01

    Full Text Available Este artículo presenta y evalúa las principales contribuciones de algunos de los estudios sobre etnicidad y relaciones étnicas en unas últimas décadas marcadas, frente a los pronósticos de diversas variantes de la teoría sociológica contemporánea, por una notable intensificación de los conflictos sociales articulados sobre lealtades y divisorias étnicas. Se exponen los avances y se identifican algunas de las lagunas y abusos que han presidido el debate entre las visiones primordialistas y construcitivistas de la etnicidad. Frente a los reduccionismos del primordialismo cultural y, tambien, de ciertas versiones encasilladas en la teoría constructivista, como los enfoques instrumentalistas radicales de la identidad étinica, se incide en la necesidad de considerar a la etnicidad como un fenómeno dual: una combinación de muchos aspectos única entre interés y adhesión primaria o afectiva, lo que dota a las asociaciones étnicas de una notable superioridad frente a otras formas de asociación colectiva como núcleo de movilización social.

  17. Nonorganic visual loss in a child due to school bullying

    Directory of Open Access Journals (Sweden)

    Dimitrios Karagiannis

    2017-04-01

    Conclusions and importance: School bullying is a potential cause of nonorganic vision loss in children. Correct diagnosis, and support by the parents and teachers might rapidly alleviate the symptoms.

  18. Research on Strategies and Methods Suppressing Permanent Magnet Demagnetization in Permanent Magnet Synchronous Motors Based on a Multi-Physical Field and Rotor Multi-Topology Structure

    Directory of Open Access Journals (Sweden)

    Lin Li

    2017-12-01

    Full Text Available In this paper, a permanent magnet synchronous motor (PMSM with sleeves on the rotor outer surface is investigated. The purpose of sleeves is to fix the permanent magnets and protect them from being destroyed by the large centrifugal force. However, the sleeve material characteristics have a great influence on the PMSM, and therewith, most of the rotor eddy-current losses are generated in the rotor sleeve, which could increase the device temperature and even cause thermal demagnetization of the magnets. Thus, a sleeve scheme design with low eddy-current losses is necessary, and a method suppressing the local temperature peak of permanent magnets is presented. The 3-D electromagnetic finite element model of a 12.5 kW, 2000 r/min PMSM with a segmented sleeve is established, and the electromagnetic field is calculated by using the finite element method. The results show the effectiveness of the presented method in reducing the eddy current losses in the rotor. Using the thermal method, it can be found that the maximum temperature position and zone of permanent magnet will change. Thus, some strategies are comparatively analyzed in order to obtain the change rule of the position and zone. The obtained conclusions may provide a useful reference for the design and research of PMSMs.

  19. Smartphone serious games for vision and hearing assessment.

    Science.gov (United States)

    Dias, Pedro; Aguiar, Bruno; Sousa, Filipe; Sousa, Augusto

    2015-01-01

    Falls are the second leading cause of accidental injury deaths worldwide. In this paper, it is intended to define methodologies that permit the evaluation of two potential factors which might have an impact on fall risk, these are: visual and hearing loss. The aim of the work developed is not to replace clinic visits, but to offer the user the means to continue the tracking of his vision and hearing at home, during the long time intervals between clinical tests. Tests conducted in a sample of our target users indicate a good ability to measure vision and hearing using an android smartphone and the proposed methodologies. While some tests require further validation, promising results were achieved in the most common tests for vision and hearing, presenting a good correlation between the system's results when compared to the traditional tests (for distance visual acuity) and the data gathered from the users (for hearing tests).

  20. Permanent multipole magnets with adjustable strength

    International Nuclear Information System (INIS)

    Halbach, K.

    1983-01-01

    Preceded by a short discussion of the motives for using permanent magnets in accelerators, a new type of permanent magnet for use in accelerators is presented. The basic design and most important properties of a quadrople will be described that uses both steel and permanent magnet material. The field gradient produced by this magnet can be adjusted without changing any other aspect of the field produced by this quadrupole. The generalization of this concept to produce other multipole fields, or combination of multipole fields, will also be presented

  1. Nanocrystalline permanent magnets with enhanced properties

    International Nuclear Information System (INIS)

    Leonowicz, M.

    2002-01-01

    Parameters of permanent magnets result from the combination of intrinsic properties such as saturation magnetization, magnetic exchange, and magnetocrystalline energy, as well as microstructural parameters such as phase structure, grain size, and orientation. Reduction of grain size into nanocrystalline regime (∼ 50 nm) leads to the enhanced remanence which derives from ferromagnetic exchange coupling between highly refined grains. In this study the fundamental phenomena, quantities, and structure parameters, which define nanophase permanent magnets are presented and discussed. The theoretical considerations are confronted with experimental data for nanocrystalline Sm-Fe-N type permanent magnets. (author)

  2. Permanent molars: Delayed development and eruption

    Directory of Open Access Journals (Sweden)

    Arathi R

    2006-05-01

    Full Text Available Delayed development and eruption of all the permanent molars is a rare phenomenon, which can cause disturbance in the developing occlusion. The eruption of permanent first and second molars is very important for the coordination of facial growth and for providing sufficient occlusal support for undisturbed mastication. In the case described, the first permanent molars were delayed in their development and were seen erupting at the age of nine and a half years. Severe disparity between the left and the right side of the dentition with respect to the rate of development of molars were also present.

  3. Reactor safety review of permanent changes

    International Nuclear Information System (INIS)

    Lam, K.F.

    1997-01-01

    Operational compliance engineers review all changes as part of a change control process. Each change, permanent or temporary, is required to undergo an intricate review process to ensure that the benefits associated with the change outweigh the risk. For permanent changes, it is necessary to ensure that the proposed design meets the nuclear safety requirements, conforms to the licensing requirements and complies with regulatory requirements. In addition, during installation of the permanent change and prior to in-service, a configuration management process is in place to align the change with operating and maintenance documents. (author)

  4. Permanent multipole magnets with adjustable strength

    International Nuclear Information System (INIS)

    Halbach, K.

    1983-03-01

    Preceded by a short discussion of the motives for using permanent magnets in accelerators, a new type of permanent magnet for use in accelerators is presented. The basic design and most important properties of a quadrupole will be described that uses both steel and permanent magnet material. The field gradient produced by this magnet can be adjusted without changing any other aspect of the field produced by this quadrupole. The generalization of this concept to produce other multipole fields, or combination of multipole fields, will also be presented

  5. Computer Vision for Timber Harvesting

    DEFF Research Database (Denmark)

    Dahl, Anders Lindbjerg

    The goal of this thesis is to investigate computer vision methods for timber harvesting operations. The background for developing computer vision for timber harvesting is to document origin of timber and to collect qualitative and quantitative parameters concerning the timber for efficient harvest...... segments. The purpose of image segmentation is to make the basis for more advanced computer vision methods like object recognition and classification. Our second method concerns image classification and we present a method where we classify small timber samples to tree species based on Active Appearance...... to the development of the logTracker system the described methods have a general applicability making them useful for many other computer vision problems....

  6. Strategic Vision: A Selected Bibliography

    National Research Council Canada - National Science Library

    Moyer, Jeannette

    2008-01-01

    Strategic Vision is an enduring theme at the U.S. Army War College. Compiled in support of this theme, this selected bibliography reflects books, documents, periodical articles, and a number of web sites...

  7. Strategic Vision. A Selected Bibliography

    National Research Council Canada - National Science Library

    Gibish, Jane

    2004-01-01

    Strategic Vision is an enduring theme at the U.S. Army War College. Compiled in support of this theme, the following bibliography reflects books, documents, and periodical articles available in our Library...

  8. Strategic Vision: A Selected Bibliography

    National Research Council Canada - National Science Library

    Gibish, Jane

    2001-01-01

    Strategic Vision is an enduring theme at the U.S. Army War College. Compiled in support of this theme, the following bibliography reflects books, documents, and periodical articles in the Army War College Library...

  9. Improved Adherence to Vision Self-monitoring with the Vision and Memory Stimulating (VMS) Journal for Non-neovascular Age-related Macular Degeneration during a Randomized Controlled Trial

    OpenAIRE

    Bittner, Ava K; Torr-Brown, Sheryl; Arnold, Ellen; Nwankwo, Antonia; Beaton, Patricia; Rampat, Radhika; Dagnelie, Gislin; Roser, Mark

    2014-01-01

    Objective An educational, interactive journal [Vision and Memory Stimulating (VMS) journal] was developed to boost patient confidence and promote long-term adherence with weekly vision self-monitoring in age-related macular degeneration (AMD) patients at risk for vision loss from new-onset neovascularization. Methods In a multicenter randomized controlled trial, 198 subjects with intermediate stage, non-neovascular AMD received the VMS journal or followed usual care (e.g. their doctor’s instr...

  10. Radioecological sensitivity of permanent grasslands

    International Nuclear Information System (INIS)

    Besson, Benoit

    2009-01-01

    The project 'SENSIB' of the Institute for Radiological Protection and Nuclear Safety (IRSN) aims at characterizing and classifying parameters with significant impact on the transfer of radioactive contaminants in the environment. This thesis is focused on permanent grassland areas. Its objectives are the analysis of the activity variations of two artificial radionuclides ( 137 Cs and 90 Sr) in the chain from soil to dairy products as well as the categorization of ecological and anthropogenic parameters, which determine the sensitivity of the studied area. For this study, in situ sampling is carried out in 15 farms in 3 different French regions (Charente, Puy-de-Dome and Jura). The sampling sites are chosen according to their natural variations (geology, altitude and climate) and the soil types. Additionally to the radiologic measurements, geographic, soil and vegetation data as well as data concerning cattle-rearing and cheese manufacturing processes are gathered. From the soil to the grass vegetation, 137 Cs transfer factors vary between 3 x 10-3 and 148 x 10-3 Bq kg-1 (dry weight) per Bq kg-1 (dry weight) (N = 73). Theses transfer factors are significantly higher in the Puy-de-Dome region than in the Jura region. The 137 Cs transfer factor from cattle feed to milk varies from 5.9 x 10-3 to 258 x 10-3 Bq kg-1 (fresh weight) per Bq kg-1 (dry weight) (N = 28). Statistically, it is higher in the Charente region. Finally, the 90 Sr transfer factor from milk to cheese ranges from 3.9 to 12.1. The studied site with the highest factor is the Jura (N = 25). The link between milk and dairy products is the stage with the most 137 Cs and 90 Sr transfers. A nonlinear approach based on a discretization method of the transfer factor with multiple comparison tests admits a classification of the sensitivity factors from soil to grass vegetation. We can determine 20 factors interfering in the 137 Cs transfer into the vegetation, for instance, the clay rate of the soils or a marker

  11. [Acquired disorders of color vision].

    Science.gov (United States)

    Lascu, Lidia; Balaş, Mihaela

    2002-01-01

    This article is a general view of acquired disorders of color vision. The revision of the best known methods and of the etiopathogenic classification is not very important in ophthalmology but on the other hand, the detection of the blue defect advertise and associated ocular pathology. There is a major interest in serious diseases as multiple sclerosis, AIDS, diabetes melitus, when the first ocular sign can be a defect in the color vision.

  12. Artificial intelligence and computer vision

    CERN Document Server

    Li, Yujie

    2017-01-01

    This edited book presents essential findings in the research fields of artificial intelligence and computer vision, with a primary focus on new research ideas and results for mathematical problems involved in computer vision systems. The book provides an international forum for researchers to summarize the most recent developments and ideas in the field, with a special emphasis on the technical and observational results obtained in the past few years.

  13. Amblyopia and Binocular Vision

    OpenAIRE

    Birch, Eileen E.

    2012-01-01

    Amblyopia is the most common cause of monocular visual loss in children, affecting 1.3% to 3.6% of children. Current treatments are effective in reducing the visual acuity deficit but many amblyopic individuals are left with residual visual acuity deficits, ocular motor abnormalities, deficient fine motor skills, and risk for recurrent amblyopia. Using a combination of psychophysical, electrophysiological, imaging, risk factor analysis, and fine motor skill assessment, the primary role of bin...

  14. Genetics Home Reference: color vision deficiency

    Science.gov (United States)

    ... my area? Other Names for This Condition color blindness color vision defects defective color vision vision defect, color ... Perception KidsHealth from the Nemours Foundation MalaCards: color blindness MalaCards: color vision deficiency Orphanet: Blue cone monochromatism Orphanet: NON ...

  15. Night Vision Manual for the Flight Surgeon.

    Science.gov (United States)

    1985-08-01

    macula and fovea centralis. 4. Duality theory of vision-extends sensitivity of vision over 100,000 times (Fig. 12). ~Im Uilting Ullmlrage WVIVIWCentral...lowered night vision capa- bilities due to disease or degenerations . F. Hypoxia 1. Decrement of central vision due to 02 lack is quite small; such as, at

  16. Periodontal healing complications following concussion and subluxation injuries in the permanent dentition: a longitudinal cohort study

    DEFF Research Database (Denmark)

    Hermann, Nuno Vibe; Lauridsen, Eva; Ahrensburg, Søren Steno

    2012-01-01

    Purpose The purpose of the study was to analyze the risk of periodontal ligament (PDL) healing complications following concussion and subluxation injuries in the permanent dentition. Material and method A total 469 permanent teeth (358 patients) with concussion and 404 permanent teeth......-related resorption (ankylosis), marginal bone loss, and tooth loss were analyzed with the Kaplan–Meier method. Results Concussion: In teeth with immature root development, no healing complications were observed. For teeth with mature root development, the risk of repair related resorption after 3 years was 3.2% (95...... among teeth with concussion. Subluxation: In teeth with immature root development, the risk of infection-related resorption after 3 years was 1.7% [95% confidence interval (CI): 0–3.8%]. Infection-related resorption occurred significantly more often in teeth with concomitant crown fracture (P = 0...

  17. A review of radiation-induced demagnetization of permanent magnets

    Science.gov (United States)

    Samin, Adib J.

    2018-05-01

    Radiation-induced demagnetization of permanent magnets is important for a number of applications including space missions, particle accelerators and robots designed to carry out rescue missions at nuclear accidents where magnet failure can lead to serious consequences. This topic has been studied by several investigators over the past three decades and in this work, a review of the available literature is conducted and some general conclusions and trends are presented. In short, it can be gleaned that magnetism loss is dependent on the type of radiation, the energy of the incoming particle and the overall dose or fluence. Furthermore, magnetism loss also shows a dependence on the type of the irradiated magnet, the coercivity of the magnet, the demagnetizing field and the temperature of irradiation.

  18. Design of permanent block stopping to resist strata convergence

    Energy Technology Data Exchange (ETDEWEB)

    Ray, R.E.

    1985-11-01

    Conventional concrete block plastered with a cementitious coating is the most common material used in the construction of permanent stoppings to direct airflow in underground mines in the US. All mines experience various degrees of strata convergence depending on depth of overburden, geological conditions, and type of roof support employed. Strata convergence will cause cracks and joint openings in masonry stoppings, resulting in significant air leakage losses. Where strata convergence is severe, complete structural failure of the stopping can ultimately occur. Reconstruction of damaged or destroyed stoppings adds expensive overheads to mining operations, and even greater expenses are incurred from the additional fan horsepower required to overcome leakage losses. Ideally, a stopping should maintain high resistance to airflow while yielding to strata convergence. By properly incorporating a polyisocyanurate rigid foam material within the masonry block structure, stopping service life can be increased in mines experiencing strata convergence problems such as floor heave, roof loading, and lateral rib movement.

  19. Stimulation of functional vision in children with perinatal brain damage.

    Science.gov (United States)

    Alimović, Sonja; Mejaski-Bosnjak, Vlatka

    2011-01-01

    Cerebral visual impairment (CVI) is one of the most common causes of bilateral visual loss, which frequently occurs due to perinatal brain injury. Vision in early life has great impact on acquisition of basic comprehensions which are fundamental for further development. Therefore, early detection of visual problems and early intervention is necessary. The aim of the present study is to determine specific visual functioning of children with perinatal brain damage and the influence of visual stimulation on development of functional vision at early age of life. We initially assessed 30 children with perinatal brain damage up to 3 years of age, who were reffered to our pediatric low vision cabinet in "Little house" from child neurologists, ophthalmologists Type and degree of visual impairment was determined according to functional vision assessment of each child. On the bases of those assessments different kind of visual stimulations were carried out with children who have been identified to have a certain visual impairment. Through visual stimulation program some of the children were stimulated with light stimulus, some with different materials under the ultraviolet (UV) light, and some with bright color and high contrast materials. Children were also involved in program of early stimulation of overall sensory motor development. Goals and methods of therapy were determined individually, based on observation of child's possibilities and need. After one year of program, reassessment was done. Results for visual functions and functional vision were compared to evaluate the improvement of the vision development. These results have shown that there was significant improvement in functional vision, especially in visual attention and visual communication.

  20. Vision after 53 years of blindness.

    Science.gov (United States)

    Sikl, Radovan; Simecček, Michal; Porubanová-Norquist, Michaela; Bezdíček, Ondřej; Kremláček, Jan; Stodůlka, Pavel; Fine, Ione; Ostrovsky, Yuri

    2013-01-01

    Several studies have shown that visual recovery after blindness that occurs early in life is never complete. The current study investigated whether an extremely long period of blindness might also cause a permanent impairment of visual performance, even in a case of adult-onset blindness. We examined KP, a 71-year-old man who underwent a successful sight-restoring operation after 53 years of blindness. A set of psychophysical tests designed to assess KP's face perception, object recognition, and visual space perception abilities were conducted six months and eight months after the surgery. The results demonstrate that regardless of a lengthy period of normal vision and rich pre-accident perceptual experience, KP did not fully integrate this experience, and his visual performance remained greatly compromised. This was particularly evident when the tasks targeted finer levels of perceptual processing. In addition to the decreased robustness of his memory representations, which was hypothesized as the main factor determining visual impairment, other factors that may have affected KP's performance were considered, including compromised visual functions, problems with perceptual organization, deficits in the simultaneous processing of visual information, and reduced cognitive abilities.

  1. Vision after 53 Years of Blindness

    Directory of Open Access Journals (Sweden)

    Radovan Šikl

    2013-12-01

    Full Text Available Several studies have shown that visual recovery after blindness that occurs early in life is never complete. The current study investigated whether an extremely long period of blindness might also cause a permanent impairment of visual performance, even in a case of adult-onset blindness. We examined KP, a 71-year-old man who underwent a successful sight-restoring operation after 53 years of blindness. A set of psychophysical tests designed to assess KP's face perception, object recognition, and visual space perception abilities were conducted six months and eight months after the surgery. The results demonstrate that regardless of a lengthy period of normal vision and rich pre-accident perceptual experience, KP did not fully integrate this experience, and his visual performance remained greatly compromised. This was particularly evident when the tasks targeted finer levels of perceptual processing. In addition to the decreased robustness of his memory representations, which was hypothesized as the main factor determining visual impairment, other factors that may have affected KP's performance were considered, including compromised visual functions, problems with perceptual organization, deficits in the simultaneous processing of visual information, and reduced cognitive abilities.

  2. Macroscopic simulation of isotropic permanent magnets

    International Nuclear Information System (INIS)

    Bruckner, Florian; Abert, Claas; Vogler, Christoph; Heinrichs, Frank; Satz, Armin; Ausserlechner, Udo; Binder, Gernot; Koeck, Helmut; Suess, Dieter

    2016-01-01

    Accurate simulations of isotropic permanent magnets require to take the magnetization process into account and consider the anisotropic, nonlinear, and hysteretic material behaviour near the saturation configuration. An efficient method for the solution of the magnetostatic Maxwell equations including the description of isotropic permanent magnets is presented. The algorithm can easily be implemented on top of existing finite element methods and does not require a full characterization of the hysteresis of the magnetic material. Strayfield measurements of an isotropic permanent magnet and simulation results are in good agreement and highlight the importance of a proper description of the isotropic material. - Highlights: • Simulations of isotropic permanent magnets. • Accurate calculation of remanence magnetization and strayfield. • Comparison with strayfield measurements and anisotropic magnet simulations. • Efficient 3D FEM–BEM coupling for solution of Maxwell equations.

  3. Genetics Home Reference: permanent neonatal diabetes mellitus

    Science.gov (United States)

    ... AL. Update on mutations in glucokinase (GCK), which cause maturity-onset diabetes of the young, permanent neonatal diabetes, and hyperinsulinemic hypoglycemia. Hum Mutat. 2009 Nov;30(11):1512-26. ...

  4. [Permanent education in health: a review].

    Science.gov (United States)

    Miccas, Fernanda Luppino; Batista, Sylvia Helena Souza da Silva

    2014-02-01

    To undertake a meta-synthesis of the literature on the main concepts and practices related to permanent education in health. A bibliographical search was conducted for original articles in the PubMed, Web of Science, LILACS, IBECS and SciELO databases, using the following search terms: "public health professional education", "permanent education", "continuing education", "permanent education health". Of the 590 articles identified, after applying inclusion and exclusion criteria, 48 were selected for further analysis, grouped according to the criteria of key elements, and then underwent meta-synthesis. The 48 original publications were classified according to four thematic units of key elements: 1) concepts, 2) strategies and difficulties, 3) public policies and 4) educational institutions. Three main conceptions of permanent education in health were found: problem-focused and team work, directly related to continuing education and education that takes place throughout life. The main strategies for executing permanent education in health are discussion, maintaining an open space for permanent education , and permanent education clusters. The most limiting factor is mainly related to directly or indirect management. Another highlight is the requirement for implementation and maintenance of public policies, and the availability of financial and human resources. The educational institutions need to combine education and service aiming to form critical-reflexive graduates. The coordination between health and education is based as much on the actions of health services as on management and educational institutions. Thus, it becomes a challenge to implement the teaching-learning processes that are supported by critical-reflexive actions. It is necessary to carry out proposals for permanent education in health involving the participation of health professionals, teachers and educational institutions. To undertake a meta-synthesis of the literature on the main concepts and

  5. Radioelement gauges. Appliances intended for permanent installation

    International Nuclear Information System (INIS)

    1975-08-01

    The present norm defines for radioelement gauges intended for permanent installation: a classification of instruments and beam shutter devices; recommended construction techniques which satisfy health physics requirements; monitoring and test methods; information which must appear on the instruments [fr

  6. Canadian Eskimo permanent tooth emergence timing.

    Science.gov (United States)

    Mayhall, J T; Belier, P L; Mayhall, M F

    1978-08-01

    To identify the times of emergence of the permanent teeth of Canadian Eskimos (Inuit), 368 children and adolescents were examined. The presence or absence of all permanent teeth except the third molars was recorded and these data subjected to probit analysis. Female emergence times were advanced over males. Generally, the Inuit of both sexes showed statistically significant earlier emergence times than Montreal children, except for the incisors. The present results do not support hypotheses indicating that premature extraction of the deciduous teeth advances the emergence of their succedaneous counterparts. There is some indication the controls of deciduous tooth emergence continue to play some part in emergence of the permanent dentition, especially the first permanent teeth that emerge.

  7. Multiple Unerupted Permanent Teeth Associated with Noonan ...

    African Journals Online (AJOL)

    [2] Oral findings in patients with NS include a high arched palate ... the atypical dental anomalies such as multiple unerupted permanent ... clinical features in a child with NS. .... Disabilities, Centers for Disease Control and Prevention (CDC).

  8. Causes of Childhood Vision Impairment in the School for the Blind in Eritrea.

    Science.gov (United States)

    Gyawali, Rajendra; Moodley, Vanessa R

    2017-12-01

    Our study provides the much-needed evidence on causes of childhood blindness in Eritrea. This will assist authorities to plan appropriate strategies and implement preventive, curative, and rehabilitative services to address these causes of vision loss in children in this resource-limited country. This study aims to identify the causes of severe vision impairment and blindness in children attending the only school for the blind in Eritrea. All children enrolled in the school were examined, and the World Health Organization form for the examination of visually impaired children was used to record the data. Examination included visual acuity, refraction, anterior segment, and fundus assessment. Causes of vision loss for children with severe vision impairment (visual acuity blindness (visual acuity blindness. The major causes of vision loss were corneal scars (16.9%), cataract (12.7%), phthisis bulbi (11.3%), congenital eye deformities (11.3%), optic atrophy (9.3%), and presumed chorioretinal Toxoplasma scars (7.0%). Hereditary factors were the major known etiological category (15.5%) followed by the sequel of eye injuries (12.7%). Blindness due to vitamin A deficiency was not found, whereas infectious causes such as measles and ophthalmia neonatorum were relatively absent (one case each). Potentially avoidable causes of vision impairment were accounted for in 47.9% of children. This study provides the first direct evidence on childhood vision impairment in Eritrea. Despite the limitations, it is clearly shown that nearly half of the vision loss is due to avoidable causes. Thus, preventive public health strategies, specialist pediatric eye care, and rehabilitative services are recommended to address childhood vision impairment in Eritrea.

  9. Elastic Band Causing Exfoliation of the Upper Permanent Central Incisors

    Directory of Open Access Journals (Sweden)

    Monica Ghislaine Oliveira Alves

    2015-01-01

    Full Text Available Objective. This study reports a case in which elastic band use culminated in the loss of the incisors. Case Report. An 11-year-old white girl was seen complaining of pain, with purulent discharge and severe tooth mobility. The bone destruction detected radiographically in the region, despite its single location and absence in posterior quadrants of the maxilla and/or mandible, was similar to that observed in Langerhans cell disease. To our surprise, an elastic band involving the midportion of the roots of the two upper central incisors was found during biopsy. The debris was removed and a metal wire was placed in permanent maxillary right and left incisors. The patient was followed up, but no improvement in tooth mobility was observed. Bone loss increased, and internal resorption and root exposure occurred, which culminated in the extraction of permanent maxillary right and left incisors. Conclusion. The present case highlights the fact that professionals sometimes are confronted by anamnestic reports never seen before.

  10. Experiencing Loss

    DEFF Research Database (Denmark)

    Kristiansen, Maria; Younis, Tarek; Hassani, Amani

    2015-01-01

    In this article, we explore how Islam, minority status and refugee experiencesintersect in shaping meaning-making processes following bereavement. We do this througha phenomenological analysis of a biographical account of personal loss told by Aisha, a Muslim Palestinian refugee living in Denmark......, who narrates her experience of losing herhusband to lung cancer. By drawing on a religious framework, Aisha creates meaning fromher loss, which enables her to incorporate this loss into her life history and sustain agency.Her narrative invites wider audiences to witness her tale of overcoming loss...

  11. Magnetic spring based on two permanent magnets

    International Nuclear Information System (INIS)

    Tsivilitsin, V.Yu.; Mil'man, Yu.V.; Goncharuk, V.A.; Bondar, I.B.

    2011-01-01

    A new type of the magnetic spring construction 'two permanent magnets' has been considered. A mathematical expression for the estimation of a pulling-in force has been offered. This expression is verified experimentally on the produced operating magnetic spring. The theoretical and experimental data are in good accordance. A number of advantages of the magnetic spring over the construction 'permanent magnet - magnetic circuit' such as an insignificant friction force between two magnets and a higher pulling force are discussed.

  12. Permanent Magnet Dipole for DIRAC Design Report

    CERN Document Server

    Vorozhtsov, Alexey

    2012-01-01

    Two dipole magnets including one spare unit are needed for the for the DIRAC experiment. The proposed design is a permanent magnet dipole. The design based on Sm2Co17 blocks assembled together with soft ferromagnetic pole tips. The magnet provides integrated field strength of 24.6 10-3 T×m inside the aperture of 60 mm. This Design Report summarizes the main magnetic and mechanic design parameters of the permanent dipole magnets.

  13. Numerical and Experimental Investigation of Heat Flow in Permanent Magnet Brushless DC Hub Motor

    DEFF Research Database (Denmark)

    Fasil, Muhammed; Plesner, Daniel; Walther, Jens Honore

    2014-01-01

    This paper investigates the heat dissipation in the hub motor of an electric two-wheeler using lumped parameter (LP), finite element (FE) and computational fluid dynamic (CFD) models. The motor uses external rotor permanent magnet brushless DC topology and nearly all of its losses are generated...

  14. Direct Driven Permanent Magnet Synchronous Generators with Diode Rectifiers for Use in Offshore Wind Turbines

    OpenAIRE

    Reigstad, Tor Inge

    2007-01-01

    This work is focused on direct-driven permanent magnets synchronous generators (PMSG) with diode rectifiers for use in offshore wind turbines. Reactive compensation of the generator, power losses and control of the generator are studied. Configurations for power transmission to onshore point of common connection are also considered. Costs, power losses, reliability and interface with the PMSG are discussed. The purpose of the laboratory tests and simulations are to learn how a PMSG with dio...

  15. EDITORIAL: Permanent revolution - or evolution?

    Science.gov (United States)

    Dobson, Ken

    1998-03-01

    Honorary Editor It was that temporary Bolshevik Leon Trotsky who developed the principle of `permanent revolution', a principle that perhaps characterizes the recent history of education in (south) Britain more than does, say, principles traditionally associated with the Conservative or Labour parties. As this editorial is being written, changes are being made to primary school education, and the long-awaited details of the post-Dearing reorganizing of post-16 education are yet to hit the overful bookshelves and filing cabinets of school heads and examination board officials. But something unique has happened recently which might have surprised even Trotsky. The Secretary of State for Education has set up targets for primary school pupils' attainment and threatened (or promised) to resign if they are not met within the lifetime of our newly elected parliament. Of course, if Mr Blunkett is still in a position to resign at that stage he will have been the longest serving Secretary of State since time immemorial. But we should not carp: this is truly a revolutionary idea. Not the promise to resign - although this idea is not so fashionable now as it once was. The revolutionary idea is that a major change to an educational process is actually being made that carries with it a predicted and testable outcome. By contrast, when school physics was refreshed a generation ago by the introduction of Nuffield courses at both pre- and post-16 stages, no `targets' were set. I and many other physics teachers certainly preferred teaching these to teaching their predecessor syllabuses, and might even dare to assert that the pupils liked them too. But we still don't really know whether or not they learned more - or even better - physics. Very little happened as far as the outside world was concerned: the usual fraction of students gave up physics at the usual ages, and those who were examined didn't really get a better reward for their more up-to-date and more enjoyably learned

  16. Workplace bullying a risk for permanent employees.

    Science.gov (United States)

    Keuskamp, Dominic; Ziersch, Anna M; Baum, Fran E; Lamontagne, Anthony D

    2012-04-01

    We tested the hypothesis that the risk of experiencing workplace bullying was greater for those employed on casual contracts compared to permanent or ongoing employees. A cross-sectional population-based telephone survey was conducted in South Australia in 2009. Employment arrangements were classified by self-report into four categories: permanent, casual, fixed-term and self-employed. Self-report of workplace bullying was modelled using multiple logistic regression in relation to employment arrangement, controlling for sex, age, working hours, years in job, occupational skill level, marital status and a proxy for socioeconomic status. Workplace bullying was reported by 174 respondents (15.2%). Risk of workplace bullying was higher for being in a professional occupation, having a university education and being separated, divorced or widowed, but did not vary significantly by sex, age or job tenure. In adjusted multivariate logistic regression models, casual workers were significantly less likely than workers on permanent or fixed-term contracts to report bullying. Those separated, divorced or widowed had higher odds of reporting bullying than married, de facto or never-married workers. Contrary to expectation, workplace bullying was more often reported by permanent than casual employees. It may represent an exposure pathway not previously linked with the more idealised permanent employment arrangement. A finer understanding of psycho-social hazards across all employment arrangements is needed, with equal attention to the hazards associated with permanent as well as casual employment. © 2012 The Authors. ANZJPH © 2012 Public Health Association of Australia.

  17. The impact of low vision on activities of daily living, symptoms of depression, feelings of anxiety and social support in community-living older adults seeking vision rehabilitation services

    NARCIS (Netherlands)

    Kempen, Gertrudis I. J. M.; Ballemans, Judith; Ranchor, Adelita V.; van Rens, Ger H. M. B.; Zijlstra, G. A. Rixt

    2012-01-01

    Purpose Previous studies showed that older persons with vision loss generally reported low levels of health-related quality of life, although study outcomes with respect to feelings of anxiety and social support were inconsistent. The objective of this study was to examine the impact of low vision

  18. The impact of low vision on activities of daily living, symptoms of depression, feelings of anxiety and social support in community-living older adults seeking vision rehabilitation services

    NARCIS (Netherlands)

    Kempen, G.I.J.M.; Ballemans, J.; Ranchor, A.V.; van Rens, G.H.M.B.; Zijlstra, G.A.R.

    2012-01-01

    Purpose: Previous studies showed that older persons with vision loss generally reported low levels of health-related quality of life, although study outcomes with respect to feelings of anxiety and social support were inconsistent. The objective of this study was to examine the impact of low vision

  19. Aging and Vision.

    Science.gov (United States)

    Alavi, Marcel V

    2016-01-01

    Aging involves defined genetic, biochemical and cellular pathways that regulate lifespan. These pathways are called longevity pathways and they have relevance for many age-related diseases. In the eye, longevity pathways are involved in the major blinding diseases, cataract, glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy. Pharmaceutical targeting of longevity pathways can extend healthy lifespan in laboratory model systems. This offers the possibility of therapeutic interventions to also delay onset or slow the progression of age-related eye diseases. I suggest that retinal degeneration may be viewed as accelerated aging of photoreceptors and that interventions extending healthy lifespan may also slow the pace of photoreceptor loss.

  20. Visual loss in a school for the blind in Nigeria.

    Science.gov (United States)

    Okoye, O I; Aghaji, A E; Ikojo, I N

    2009-01-01

    There are an estimated 1.4 million blind children worldwide, it has been observed that almost 90% of the so-called blind population (children inclusive) do not have total loss of visual function, but retain a degree of usable residual vision. The study aims to determined the sites and causes of visual loss in the students of a school for the blind in Nigeria, and also the proportion of those students who could benefit from low vision devices. Forty-five students of the school were examined using the standard World Health Organization/Prevention of blindness examination record for childhood blindness. Refraction and assessment for low vision devices were conducted, where necessary. Glaucoma/buphthalmos (22.2%) and corneal lesions (20%) were the major causes of vision loss. Six students (13.3%) benefited from spectacles and/or low vision devices. Glaucoma/buphthalmos is assuming great significance in this study population, though most of the causes of vision loss are avoidable (77.7%). There is need for low vision service in the schools for the blind in South East Nigeria.

  1. Multi-characteristic opsin enabled vision restoration

    Science.gov (United States)

    Wright, Weldon; Pradhan, Sanjay; Bhattacharya, Sulgana; Mahapatra, Vasu; Tripathy, Ashutosh; Gajjeraman, Sivakumar; Mohanty, Samarendra

    2017-02-01

    Photodegenerative retinal diseases such as retinitis pigmentosa (RP) and dry age related macular degeneration (dry- AMD) lead to loss of vision in millions of individuals. Currently, no surgical or medical treatment is available though optogenetic therapies are in clinical development. Here, we demonstrate vision restoration using Multi- Characteristics Opsin (MCO1) in animal models with photo-degenerated retina. MCO1 is reliably delivered to specific retinal cells via intravitreal injection of Adeno-Associated Virus, leading to significant improvement in visually guided behavior conducted using a radial-arm water maze. The time to reach platform significantly reduced after delivery of MCO1. Notably, the improvement in visually guided behavior was observed even at light intensity levels orders of magnitude lower than that required for Channelrhodopsin-2 opsin. Chronic light exposure study showed that chronic light exposure did not compromise viability of vMCO1-treated retina. Safe virus-mediated MCO1-delivery has potential for effective gene therapy of diverse retinal degenerations in patients.

  2. Memory loss

    Science.gov (United States)

    ... barbiturates or ( hypnotics ) ECT (electroconvulsive therapy) (most often short-term memory loss) Epilepsy that is not well controlled Illness that ... appointment. Medical history questions may include: Type of memory loss, such as short-term or long-term Time pattern, such as how ...

  3. The mediating role of disability and social support in the association between low vision and depressive symptoms in older adults

    NARCIS (Netherlands)

    Kempen, Gertrudis I. J. M.; Ranchor, Adelita V.; Ambergen, Ton; Zijlstra, G. A. Rixt

    Vision loss is highly prevalent in old age and has a substantial impact on different aspects of quality of life including depressive symptoms. Our objective was to examine the mediating role of disability and social support in the association between low vision and depressive symptoms. Differences

  4. [Ophthalmologist and "computer vision syndrome"].

    Science.gov (United States)

    Barar, A; Apatachioaie, Ioana Daniela; Apatachioaie, C; Marceanu-Brasov, L

    2007-01-01

    The authors had tried to collect the data available on the Internet about a subject that we consider as being totally ignored in the Romanian scientific literature and unexpectedly insufficiently treated in the specialized ophthalmologic literature. Known in the specialty literature under the generic name of "Computer vision syndrome", it is defined by the American Optometric Association as a complex of eye and vision problems related to the activities which stress the near vision and which are experienced in relation, or during, the use of the computer. During the consultations we hear frequent complaints of eye-strain - asthenopia, headaches, blurred distance and/or near vision, dry and irritated eyes, slow refocusing, neck and backache, photophobia, sensation of diplopia, light sensitivity, and double vision, but because of the lack of information, we overlooked them too easily, without going thoroughly into the real motives. In most of the developed countries, there are recommendations issued by renowned medical associations with regard to the definition, the diagnosis, and the methods for the prevention, treatment and periodical control of the symptoms found in computer users, in conjunction with an extremely detailed ergonomic legislation. We found out that these problems incite a much too low interest in our country. We would like to rouse the interest of our ophthalmologist colleagues in the understanding and the recognition of these symptoms and in their treatment, or at least their improvement, through specialized measures or through the cooperation with our specialist occupational medicine colleagues.

  5. Reinforcement learning in computer vision

    Science.gov (United States)

    Bernstein, A. V.; Burnaev, E. V.

    2018-04-01

    Nowadays, machine learning has become one of the basic technologies used in solving various computer vision tasks such as feature detection, image segmentation, object recognition and tracking. In many applications, various complex systems such as robots are equipped with visual sensors from which they learn state of surrounding environment by solving corresponding computer vision tasks. Solutions of these tasks are used for making decisions about possible future actions. It is not surprising that when solving computer vision tasks we should take into account special aspects of their subsequent application in model-based predictive control. Reinforcement learning is one of modern machine learning technologies in which learning is carried out through interaction with the environment. In recent years, Reinforcement learning has been used both for solving such applied tasks as processing and analysis of visual information, and for solving specific computer vision problems such as filtering, extracting image features, localizing objects in scenes, and many others. The paper describes shortly the Reinforcement learning technology and its use for solving computer vision problems.

  6. Relationship between upper extremity kinesthetic sense and writing performance by students with low vision.

    Science.gov (United States)

    Aki, Esra; Atasavun, Songül; Kayihan, Holya

    2008-06-01

    Kinesthetic sense plays an important role in writing. Children with low vision lack sensory input from the environment given their loss of vision. This study assessed the effect of upper extremity kinesthetic sense on writing function in two groups, one of students with low vision (9 girls and 11 boys, 9.4 +/- 1.9 yr. of age) and one of sighted students (10 girls and 10 boys, 10.1 +/- 1.3 yr. of age). All participants were given the Kinesthesia Test and Jebsen Hand Function Test-Writing subtest. Students with low vision scored lower on kinesthetic perception and writing performance than sighted peers. The correlation between scores for writing performance and upper extremity kinesthetic sense in the two groups was significant (r = -.34). The probability of deficiencies in kinesthetic information in students with low vision must be remembered.

  7. Amblyopia and binocular vision.

    Science.gov (United States)

    Birch, Eileen E

    2013-03-01

    Amblyopia is the most common cause of monocular visual loss in children, affecting 1.3%-3.6% of children. Current treatments are effective in reducing the visual acuity deficit but many amblyopic individuals are left with residual visual acuity deficits, ocular motor abnormalities, deficient fine motor skills, and risk for recurrent amblyopia. Using a combination of psychophysical, electrophysiological, imaging, risk factor analysis, and fine motor skill assessment, the primary role of binocular dysfunction in the genesis of amblyopia and the constellation of visual and motor deficits that accompany the visual acuity deficit has been identified. These findings motivated us to evaluate a new, binocular approach to amblyopia treatment with the goals of reducing or eliminating residual and recurrent amblyopia and of improving the deficient ocular motor function and fine motor skills that accompany amblyopia. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Stabilization of magnet assemblies of permanent magnet sodium flowmeters used in fast breeder reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, K.K., E-mail: kkrajan@igcar.gov.in; Vijayakumar, G.

    2014-08-15

    Highlights: • Stabilization procedure for ALNICO-5 permanent magnet material is evolved. • Effect of time and temperature on ALNICO-5 assembly is determined. • Suitability of ALNICO-5 flowmeters at high temperatures is established. • Temperature coefficient of flux density is determined. - Abstract: Permanent magnet flow meters (PMFMs) are used to measure the sodium flow in sodium cooled Fast Breeder Reactor Circuits. Prototype fast breeder reactor (PFBR) which is under construction at Kalpakkam is a 500 MWe, sodium cooled, pool type reactor. Sodium flow measurement in various loops of the reactor is of prime importance from operational and safety point of view. To measure the flow of electrically conducting liquid sodium, in primary and secondary circuit pipe lines of PFBR, permanent magnet flow meters are used. PMFM is a non-invasive device, which works on the principle of generation of motional EMF by magnetic forces exerted on the charges in a moving conductor. Flowmeters of different pipe sizes ranging from 10 mm to 200 mm pipe diameter are required for PFBR. Long term performance of the flowmeters mainly depends on stability of permanent magnets used in flowmeters to generate constant magnetic field in stainless steel (SS) pipes. This paper describes the effects of time and temperature on permanent magnet assemblies made of ALNICO-V used in PFBR flowmeters. The stabilization methodology for ALNICO-V permanent magnet assemblies is evolved and established. Loss of magnetic field strength with respect to time and temperatures is determined by experiments and found negligible.

  9. Design improvement of permanent magnet flux switching motor with dual rotor structure

    Science.gov (United States)

    Soomro, H. A.; Sulaiman, E.; Kumar, R.; Rahim, N. S.

    2017-08-01

    This paper presents design enhancement to reduce permanent magnet (PM) volume for 7S-6P-7S dual rotor permanent magnet flux-switching machines (DRPMFSM) for electric vehicle application. In recent years, Permanent magnet flux switching (PMFS) motor and a new member of brushless permanent magnet machine are prominently used for the electric vehicle. Though, more volume of Rare-Earth Permanent Magnet (REPM) is used to increase the cost and weight of these motors. Thus, to overcome the issue, new configuration of 7S-6P- 7S dual rotor permanent magnet flux-switching machine (DRPMFSM) has been proposed and investigated in this paper. Initially proposed 7S-6P-7S DRPMFSM has been optimized using “deterministic optimization” to reduce the volume of PM and to attain optimum performances. In addition, the performances of initial and optimized DRPMFSM have been compared such that back-emf, cogging torque, average torque, torque and power vs speed performances, losses and efficiency have been analysed by 2D-finite element analysis (FEA) using the JMAG- Designer software ver. 14.1. Consequently, the final design 7S-6P-7S DRPMFSM has achieved the efficiency of 83.91% at reduced PM volume than initial design to confirm the better efficient motor for HEVs applications.

  10. Stimulation of Functional Vision in Children with Perinatal Brain Damage

    OpenAIRE

    Alimović, Sonja; Mejaški-Bošnjak, Vlatka

    2011-01-01

    Cerebral visual impairment (CVI) is one of the most common causes of bilateral visual loss, which frequently occurs due to perinatal brain injury. Vision in early life has great impact on acquisition of basic comprehensions which are fundamental for further development. Therefore, early detection of visual problems and early intervention is necessary. The aim of the present study is to determine specific visual functioning of children with perinatal brain damage and the influence of visual st...

  11. Profile of Low Vision Population Attending Low Vision Clinic in a Peripheral Eye Hospital in Nepal

    OpenAIRE

    Safal Khanal, BOptom; Pekila Lama, MD

    2013-01-01

    Background: Blindness and low vision are major causes of morbidity and constitute a significant public health problem, both detrimental to the quality of life for the individual and an economic burden on the individual, family, and society in general. People with low vision have the potential for enhancement of functional vision if they receive the appropriate low vision services. The present study aims to determine the profile of the low vision population attending a low vision clinic at a p...

  12. Sensorineural hearing loss after magnetic resonance imaging

    DEFF Research Database (Denmark)

    Mollasadeghi, Abolfazl; Mehrparvar, Amir Houshang; Atighechi, Saeid

    2013-01-01

    Magnetic resonance imaging (MRI) devices produce noise, which may affect patient's or operators' hearing. Some cases of hearing impairment after MRI procedure have been reported with different patterns (temporary or permanent, unilateral or bilateral, with or without other symptoms like tinnitus......). In this report, a case of bilateral sensorineural hearing loss in an otherwise healthy patient underwent brain MRI was described. The patient's hearing loss was accompanied with tinnitus and was not improved after 3 months of followup....

  13. Vision and the Nobel Prize.

    Science.gov (United States)

    Morais, Fábio Barreto

    2018-04-01

    The Nobel Prize is the world's foremost honor for scientific advances in medicine and other areas. Founded by Alfred Nobel, the prizes have been awarded annually since 1901. We reviewed the literature on persons who have won or competed for this prize in subjects related to vision and ophthalmology. The topics were divided into vision physiology, diagnostic and therapeutic methods, disease mechanism, and miscellaneous categories. Allvar Gullstrand is the only ophthalmologist to win a Nobel Prize; he is also the only one to receive it for work in ophthalmology. Other ophthalmologists that have been nominated were Hjalmar Schiötz (tonometer), Karl Koller (topical anesthesia), and Jules Gonin (retinal detachment). Other scientists have won the prize for eye-related research: Ragnar Granit, Haldan Hartline and George Wald (chemistry and physiology of vision), and David Hubel and Torsten Wiesel (processing in the visual system). Peter Medawar is the only person born in Brazil to have won the Nobel Prize.

  14. Quantum vision in three dimensions

    Science.gov (United States)

    Roth, Yehuda

    We present four models for describing a 3-D vision. Similar to the mirror scenario, our models allow 3-D vision with no need for additional accessories such as stereoscopic glasses or a hologram film. These four models are based on brain interpretation rather than pure objective encryption. We consider the observer "subjective" selection of a measuring device and the corresponding quantum collapse into one of his selected states, as a tool for interpreting reality in according to the observer concepts. This is the basic concept of our study and it is introduced in the first model. Other models suggests "soften" versions that might be much easier to implement. Our quantum interpretation approach contribute to the following fields. In technology the proposed models can be implemented into real devices, allowing 3-D vision without additional accessories. Artificial intelligence: In the desire to create a machine that exchange information by using human terminologies, our interpretation approach seems to be appropriate.

  15. Rebalancing binocular vision in amblyopia.

    Science.gov (United States)

    Ding, Jian; Levi, Dennis M

    2014-03-01

    Humans with amblyopia have an asymmetry in binocular vision: neural signals from the amblyopic eye are suppressed in the cortex by the fellow eye. The purpose of this study was to develop new models and methods for rebalancing this asymmetric binocular vision by manipulating the contrast and luminance in the two eyes. We measured the perceived phase of a cyclopean sinewave by asking normal and amblyopic observers to indicate the apparent location (phase) of the dark trough in the horizontal cyclopean sine wave relative to a black horizontal reference line, and used the same stimuli to measure perceived contrast by matching the binocular combined contrast to a standard contrast presented to one eye. We varied both the relative contrast and luminance of the two eyes' inputs, in order to rebalance the asymmetric binocular vision. Amblyopic binocular vision becomes more and more asymmetric the higher the stimulus contrast or spatial frequency. Reanalysing our previous data, we found that, at a given spatial frequency, the binocular asymmetry could be described by a log-linear formula with two parameters, one for the maximum asymmetry and one for the rate at which the binocular system becomes asymmetric as the contrast increases. Our new data demonstrates that reducing the dominant eye's mean luminance reduces its suppression of the non-dominant eye, and therefore rebalances the asymmetric binocular vision. While the binocular asymmetry in amblyopic vision can be rebalanced by manipulating the relative contrast or luminance of the two eyes at a given spatial frequency and contrast, it is very difficult or even impossible to rebalance the asymmetry for all visual conditions. Nonetheless, wearing a neutral density filter before the dominant eye (or increasing the mean luminance in the non-dominant eye) may be more beneficial than the traditional method of patching the dominant eye for treating amblyopia. © 2014 The Authors Ophthalmic & Physiological Optics © 2014 The

  16. Permanent magnet materials and their application

    International Nuclear Information System (INIS)

    Campbell, P.

    1994-01-01

    Permanent magnets are of great industrial importance in industrial drives, consumer products, computers, and automobiles. Since 1970, new classes of magnet materials have been developed. This book reviews the older and newer materials and is presented as a comprehensive design text for permanent magnets and their applications. After an initial chapter on the fundamentals of magnetism, the author discusses magnetic physics considerations specific to permanent magnets and describes the fabrications and characteristics of commercial materials: alnico, samarium-cobalt, ferrite, and neodymium-iron-boron. Thermal stability, magnet design procedures, magnetic field analysis methods, and measurement methods are discussed in subsequent chapters, followed by a concluding chapter reviewing commercial and industrial products that use permanent magnets. The chapter on thermal properties of magnet materials is of particular interest, bringing together information not readily found elsewhere. The review of applications is also deserving of attention, specifically the sections on motors and actuators. Although particle accelerator applications are discussed, the use of permanent magnet sextuples in modern ECR ion sources is not mentioned

  17. Cylindrical Hall Thrusters with Permanent Magnets

    International Nuclear Information System (INIS)

    Raitses, Yevgeny; Merino, Enrique; Fisch, Nathaniel J.

    2010-01-01

    The use of permanent magnets instead of electromagnet coils for low power Hall thrusters can offer a significant reduction of both the total electric power consumption and the thruster mass. Two permanent magnet versions of the miniaturized cylindrical Hall thruster (CHT) of different overall dimensions were operated in the power range of 50W-300 W. The discharge and plasma plume measurements revealed that the CHT thrusters with permanent magnets and electromagnet coils operate rather differently. In particular, the angular ion current density distribution from the permanent magnet thrusters has an unusual halo shape, with a majority of high energy ions flowing at large angles with respect to the thruster centerline. Differences in the magnetic field topology outside the thruster channel and in the vicinity of the channel exit are likely responsible for the differences in the plume characteristics measured for the CHTs with electromagnets and permanent magnets. It is shown that the presence of the reversing-direction or cusp-type magnetic field configuration inside the thruster channel without a strong axial magnetic field outside the thruster channel does not lead to the halo plasma plume from the CHT.

  18. Armature reaction of permanent magnet-excited small dc motors with shell type magnets and possibilities of power increase

    Energy Technology Data Exchange (ETDEWEB)

    Gutt, H J; Tran, Q N

    1983-07-01

    Permanent magnet-excited small dc motors allow an increase of power up to 30% compared with present permanent excited motors. The calculation of immediate irreversible demagnetization of the air-gap situated shell type magnets is necessary for a good motor design. Numerical calculated field line plots show the critical zones of the irreversible demagnetization at high armature reaction and refer how to avoid the flux loss and to increase the motor power.

  19. Eruption of first permanent incisors and live weight gain in grazing yearling Angora goats.

    Science.gov (United States)

    McGregor, B A; Butler, K L

    2013-05-01

    To investigate the effects of the timing and duration of eruption of the first permanent incisors, live weight, sex and other factors on contemporaneous live weight gain in Angora goats. Goats were previously part of a pen study on the effects of energy intake of Angora does during pregnancy and lactation on kid development. The design was 3 levels of nutrition in mid-pregnancy by 2 levels of postnatal nutrition in 17 randomised blocks. Artificial insemination, ultrasound examination and feeding does in pens enabled accurate conduct of the study. After weaning, goats were grazed in sex groups. Live weight change between 14 and 20 months of age was related to deciduous first incisor loss and permanent first incisor development and other attributes assessed before the study. Live weight change was related to the elapsed time for first permanent incisors to commence eruption and to the length of time for first permanent incisors to erupt. This response was affected by sex. Over summer and autumn, entire males with short eruption intervals gained 2-3 kg more than entire males with long eruption intervals. Females that reached first permanent incisor eruption by mid-summer had a live weight gain of 3 kg more than those that reached the same development 3 months later. Live weight change in yearling Angora goats was associated with the process of first permanent incisor eruption. In females, live weight gain was greater when first permanent incisor eruption was earlier. In males, live weight gain was greater when first permanent incisor eruption was faster. © 2013 The Authors. Australian Veterinary Journal © 2013 Australian Veterinary Association.

  20. Advances in embedded computer vision

    CERN Document Server

    Kisacanin, Branislav

    2014-01-01

    This illuminating collection offers a fresh look at the very latest advances in the field of embedded computer vision. Emerging areas covered by this comprehensive text/reference include the embedded realization of 3D vision technologies for a variety of applications, such as stereo cameras on mobile devices. Recent trends towards the development of small unmanned aerial vehicles (UAVs) with embedded image and video processing algorithms are also examined. The authoritative insights range from historical perspectives to future developments, reviewing embedded implementation, tools, technolog

  1. Christina Mosegaards barok-vision

    DEFF Research Database (Denmark)

    Isar, Nicoletta

    2008-01-01

      Christina Mosegaards barok-vision: om folder, ansigter og stilhed Det mest fængslende ved Christinas billeder er ved første øjekast den slående kontrast mellem roen i hendes ikonagtige ansigter og den dramatiske drejende bevægelse i stoffolderne. Men er de nu så radikalt forskellige i deres nat...... under sløret. Hun forbliver tro mod sin særegne vision i ikonerne, som i deres hudvæv gentager det opal-agtige og iriserende i marmorfoldens årer....

  2. Weight Loss

    Science.gov (United States)

    ... Rights Employment Discrimination Health Care Professionals Law Enforcement Driver's License For Lawyers Food & Fitness Home Food MyFoodAdvisor ... Fit Types of Activity Weight Loss Assess Your Lifestyle Getting Started Food Choices In My Community Home ...

  3. Object recognition in images by human vision and computer vision

    NARCIS (Netherlands)

    Chen, Q.; Dijkstra, J.; Vries, de B.

    2010-01-01

    Object recognition plays a major role in human behaviour research in the built environment. Computer based object recognition techniques using images as input are challenging, but not an adequate representation of human vision. This paper reports on the differences in object shape recognition

  4. CRALBP supports the mammalian retinal visual cycle and cone vision

    OpenAIRE

    Xue, Yunlu; Shen, Susan Q.; Jui, Jonathan; Rupp, Alan C.; Byrne, Leah C.; Hattar, Samer; Flannery, John G.; Corbo, Joseph C.; Kefalov, Vladimir J.

    2015-01-01

    Mutations in the cellular retinaldehyde-binding protein (CRALBP, encoded by RLBP1) can lead to severe cone photoreceptor-mediated vision loss in patients. It is not known how CRALBP supports cone function or how altered CRALBP leads to cone dysfunction. Here, we determined that deletion of Rlbp1 in mice impairs the retinal visual cycle. Mice lacking CRALBP exhibited M-opsin mislocalization, M-cone loss, and impaired cone-driven visual behavior and light responses. Additionally, M-cone dark ad...

  5. 31 CFR 515.335 - Permanent resident alien.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Permanent resident alien. 515.335... Definitions § 515.335 Permanent resident alien. As used in § 515.208, the term permanent resident alien means an alien lawfully admitted for permanent residence into the United States. [61 FR 37386, July 18...

  6. 13 CFR 120.900 - Sources of permanent financing.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Sources of permanent financing... Development Company Loan Program (504) Permanent Financing § 120.900 Sources of permanent financing. Permanent financing for each Project must come from three sources: the Borrower's contribution, Third-Party Loans, and...

  7. Static devices with new permanent magnets

    International Nuclear Information System (INIS)

    Chavanne, J.; Laforest, J.; Pauthenet, R.

    1987-01-01

    The high remanence and coercivity of the new permanent magnet materials are of special interest in the static applications. High ordering temperature and are uniaxial anisotropy at the origin of their good permanent magnet properties are obtained in rare earth-transition metal compounds. Binary SmCo/sub 5/ and Sm/sub 2/Co/sub 17/ and ternary Nd/sub 2/Fe/sub 14/B compounds are the basis materials of the best permanent magnets. new concepts of calculations of static devices with these magnets can be applied: the magnetization can be considered as ridig, the density of the surface Amperian current is constant, the relative permeability is approximately 1 and the induction calculations are linear. Examples of hexapoles with Sm-Co and NdFeB magnets are described and the performances are compared. The problems of temperature behavior and corrosion resistance are underlined

  8. The history of permanent magnet materials

    International Nuclear Information System (INIS)

    Livingston, J.D.

    1990-01-01

    Permanent-magnet materials play a large and growing, but largely unseen, role in today's technology. Many common devices in the home and elsewhere, including appliances, computers and printers, contain permanent-magnet motors and actuators. The growth of applications for permanent magnets results in large part from the improvements in magnetic properties, which allow the engineer to design smaller, lighter and more efficient devices. The properties of the greatest technological interest are remanence, coercivity and maximum energy product. All are non-equilibrium and high structure-sensitive. Coercivity is particularly sensitive to microstructure, while remanence is sensitive to texture (crystallographic alignment). The energy product depends on both coercivity and remanence. The more than one hundredfold increase in the available energy product in this century, and the corresponding amount of magnet required for a specific application, are shown

  9. Review: Familiarity to Vision Rehabilitation Process

    Directory of Open Access Journals (Sweden)

    Nasser Sadegh-Pour

    2006-10-01

    Full Text Available Considering the numbers of low vision patients who have been visited and treated in eye clinics, sometimes there is no exact treatment to increase their visual acuity. Therefore, the necessity to pay attention to vision rehabilitation for them is strongly felt. The aims of this essay are to define vision rehabilitation and its process in relevant centers (called Low Vision Clinic.The statistic of low vision people is reported and the method of collecting data is described. Standard definition, causes of low vision and related diseases (congenital, heredity, acquired… are explained. In addition, low vision aids and role of test and prescription are discussed. Sometimes ophthalmologists and optometrists can not exactly cure patient to raise their V.A because there is no treatment or drug or ordinary glasses. In these cases the clients should refer to low vision clinic and visit low vision specialist on vision rehabilitation process. After primary evaluation they are tested completely and at the end are prescribed proper low vision aid and also provided with advice in relation to career, education role and training techniques especially in children. At the last part of present dissertation, some examples are provided to show effectiveness of vision rehabilitation and low vision aid among the clients in different countries.

  10. Analysis of a spherical permanent magnet actuator

    International Nuclear Information System (INIS)

    Wang, J.; Jewell, G.W.; Howe, D.

    1997-01-01

    This paper describes a new form of actuator with a spherical permanent magnet rotor and a simple winding arrangement, which is capable of a high specific torque by utilizing a rare-earth permanent magnet. The magnetic-field distribution is established using an analytical technique formulated in spherical coordinates, and the results are validated by finite element analysis. The analytical field solution allows the prediction of the actuator torque and back emf in closed forms. In turn, these facilitate the characterization of the actuator and provide a firm basis for design optimization, system dynamic modeling, and closed-loop control law development. copyright 1997 American Institute of Physics

  11. Permanent isolation surface barrier: Functional performance

    International Nuclear Information System (INIS)

    Wing, N.R.

    1993-10-01

    This document presents the functional performance parameters for permanent isolation surface barriers. Permanent isolation surface barriers have been proposed for use at the Hanford Site (and elsewhere) to isolate and dispose of certain types of waste in place. Much of the waste that would be disposed of using in-place isolation techniques is located in subsurface structures, such as solid waste burial grounds, tanks, vaults, and cribs. Unless protected in some way, the wastes could be transported to the accessible environment via transport pathways, such as water infiltration, biointrusion, wind and water erosion, human interference, and/or gaseous release

  12. Magnetic guns with cylindrical permanent magnets

    DEFF Research Database (Denmark)

    Vokoun, David; Beleggia, Marco; Heller, Luděk

    2012-01-01

    The motion of a cylindrical permanent magnet (projectile) inside a tubular permanent magnet, with both magnets magnetized axially, illustrates nicely the physical principles behind the operation of magnetic guns. The force acting upon the projectile is expressed semi-analytically as derivative...... of the magnetostatic interaction energy. For comparison, the forces involved are also calculated numerically using finite elements methods. Based on the conservation of the magnetostatic and kinetic energies, the exit and asymptotic velocities are determined. The derived formulas can be used to optimize the generated...... forces and motion of the inner cylindrical magnet....

  13. Ocular Complications Following Autologous Fat Injections into Facial Area: Case Report of a Recovery from Visual Loss After Ophthalmic Artery Occlusion and a Review of the Literature.

    Science.gov (United States)

    Szantyr, Aleksandra; Orski, Michał; Marchewka, Ida; Szuta, Mariusz; Orska, Małgorzata; Zapała, Jan

    2017-06-01

    With the increase in popularity of the use of cosmetic fillers in plastic and esthetic surgery, the possibility of severe ocular complications should not be neglected. Of the fillers used, autologous fat is the most common to cause permanent visual deterioration, one of the most severe complications associated with the use of cosmetic fillers. Here we present the first report of a complete recovery of visual acuity from an instance of visual loss with no light perception caused by ophthalmic artery occlusion of the right eye following autologous fat injection in the facial area. Immediate ophthalmological intervention and comprehensive therapy with prostaglandins and vinpocetine made it possible to restore retinal perfusion and achieve complete recovery of visual acuity. Awareness of the iatrogenic artery occlusions associated with facial fillers and the need for immediate treatment should be popularized among injectors to prevent devastating consequences, such as permanent vision loss. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  14. Influence of {gamma} and neutron irradiation on the magnetic properties of Nd Fe B, Alnico, and Mn Al type permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Jipa, S; Setnescu, R; Kappel, W; Alexandru, St [Institute of Research and Design for Electrical Engineering, ICPE - Electrostatica, Splaiul Unirii 313, Sect. 3, R-74204 Bucharest (Romania)

    1996-12-31

    The influence of {gamma} and neutron irradiation on the magnetic properties of Nd Fe B, Alnico and Mn Al type permanent magnets was studied. With the used neutron energies and fluences, no changes in remanent induction values for Nd Fe B type permanent magnets are shown. For Alnico type permanent magnets the remanent induction changes are due to reversible variation of the magnetization directions. Only in case of Mn Al type permanent magnets irreversible structural changes take place, which lead to irreversible losses of induction. (author) 4 figs., 2 tabs., 12 refs. (author).

  15. Influence of γ and neutron irradiation on the magnetic properties of Nd Fe B, Alnico, and Mn Al type permanent magnets

    International Nuclear Information System (INIS)

    Jipa, S.; Setnescu, R.; Kappel, W.; Alexandru, St.

    1995-01-01

    The influence of γ and neutron irradiation on the magnetic properties of Nd Fe B, Alnico and Mn Al type permanent magnets was studied. With the used neutron energies and fluences, no changes in remanent induction values for Nd Fe B type permanent magnets are shown. For Alnico type permanent magnets the remanent induction changes are due to reversible variation of the magnetization directions. Only in case of Mn Al type permanent magnets irreversible structural changes take place, which lead to irreversible losses of induction. (author) 4 figs., 2 tabs., 12 refs. (author)

  16. Visions of Vision: An Exploratory Study of the Role College and University Presidents Play in Developing Institutional Vision

    Science.gov (United States)

    McWade, Jessica C.

    2014-01-01

    This qualitative research explores how college and university presidents engage in the process of developing formal institutional vision. The inquiry identifies roles presidents play in vision development, which is often undertaken as part of strategic-planning initiatives. Two constructs of leadership and institutional vision are used to examine…

  17. Return of the Vision Video

    DEFF Research Database (Denmark)

    Vistisen, Peter; Poulsen, Søren Bolvig

    2017-01-01

    This paper examines the role of corporate vision videos as a possible setting for participation when exploring the future potentials (and pitfalls) of new technological concepts. We propose that through the recent decade’s rise web 2.0 platforms, and the viral effects of user sharing, the corpora...

  18. Assessing Functional Vision Using Microcomputers.

    Science.gov (United States)

    Spencer, Simon; Ross, Malcolm

    1989-01-01

    The paper describes a software system which uses microcomputers to aid in the assessment of functional vision in visually impaired students. The software also aims to be visually stimulating and to develop hand-eye coordination, visual memory, and cognitive abilities. (DB)

  19. Progress in color night vision

    NARCIS (Netherlands)

    Toet, A.; Hogervorst, M.A.

    2012-01-01

    We present an overview of our recent progress and the current state-of-the-art techniques of color image fusion for night vision applications. Inspired by previously developed color opponent fusing schemes, we initially developed a simple pixel-based false color-mapping scheme that yielded fused

  20. Faculty Perceptions of Strategic Visioning.

    Science.gov (United States)

    Marcus, Laurence R.; Smith, Richard

    This report presents an examination of the use of a participative model in the strategic planning process at a publicly-supported, comprehensive institution in the middle Atlantic region of the United States. Specific attention is given to the process of developing the vision statement, an undertaking of approximately 15 months preceding Board of…

  1. Smart vision chips: An overview

    Science.gov (United States)

    Koch, Christof

    1994-01-01

    This viewgraph presentation presents four working analog VLSI vision chips: (1) time-derivative retina, (2) zero-crossing chip, (3) resistive fuse, and (4) figure-ground chip; work in progress on computing motion and neuromorphic systems; and conceptual and practical lessons learned.

  2. Real-time vision systems

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.; Hernandez, J.E.; Lu, Shin-yee [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    Many industrial and defence applications require an ability to make instantaneous decisions based on sensor input of a time varying process. Such systems are referred to as `real-time systems` because they process and act on data as it occurs in time. When a vision sensor is used in a real-time system, the processing demands can be quite substantial, with typical data rates of 10-20 million samples per second. A real-time Machine Vision Laboratory (MVL) was established in FY94 to extend our years of experience in developing computer vision algorithms to include the development and implementation of real-time vision systems. The laboratory is equipped with a variety of hardware components, including Datacube image acquisition and processing boards, a Sun workstation, and several different types of CCD cameras, including monochrome and color area cameras and analog and digital line-scan cameras. The equipment is reconfigurable for prototyping different applications. This facility has been used to support several programs at LLNL, including O Division`s Peacemaker and Deadeye Projects as well as the CRADA with the U.S. Textile Industry, CAFE (Computer Aided Fabric Inspection). To date, we have successfully demonstrated several real-time applications: bullet tracking, stereo tracking and ranging, and web inspection. This work has been documented in the ongoing development of a real-time software library.

  3. Frame Rate and Human Vision

    Science.gov (United States)

    Watson, Andrew B.

    2012-01-01

    To enhance the quality of the theatre experience, the film industry is interested in achieving higher frame rates for capture and display. In this talk I will describe the basic spatio-temporal sensitivities of human vision, and how they respond to the time sequence of static images that is fundamental to cinematic presentation.

  4. Vision - Gateway to the brain

    CERN Multimedia

    1999-01-01

    Is the brain the result of (evolutionary) tinkering, or is it governed by natural law? How can we objectively know? What is the nature of consciousness? Vision research is spear-heading the quest and is making rapid progress with the help of new experimental, computational and theoretical tools. At the same time it is about to lead to important technical applications.

  5. Tunnel Vision in Environmental Management.

    Science.gov (United States)

    Miller, Alan

    1982-01-01

    Discusses problem-solving styles in environmental management and the specific deficiencies in these styles that might be grouped under the label "tunnel vision," a form of selective attention contributing to inadequate problem-formulation, partial solutions to complex problems, and generation of additional problems. Includes educational…

  6. Machine Learning for Robotic Vision

    OpenAIRE

    Drummond, Tom

    2018-01-01

    Machine learning is a crucial enabling technology for robotics, in particular for unlocking the capabilities afforded by visual sensing. This talk will present research within Prof Drummond’s lab that explores how machine learning can be developed and used within the context of Robotic Vision.

  7. The Common Vision. Reviews: Books.

    Science.gov (United States)

    Chattin-McNichols, John

    1998-01-01

    Reviews Marshak's book describing the work of educators Maria Montessori, Rudolf Steiner, Aurobindo Ghose, and Inayat Khan. Maintains that the book gives clear, concise information on each educator and presents a common vision for children and their education; also maintains that it gives theoretical and practical information and discusses…

  8. Computer vision and machine learning for archaeology

    NARCIS (Netherlands)

    van der Maaten, L.J.P.; Boon, P.; Lange, G.; Paijmans, J.J.; Postma, E.

    2006-01-01

    Until now, computer vision and machine learning techniques barely contributed to the archaeological domain. The use of these techniques can support archaeologists in their assessment and classification of archaeological finds. The paper illustrates the use of computer vision techniques for

  9. Cities and Climate - What Visions?

    International Nuclear Information System (INIS)

    Haentjens, Jean

    2015-01-01

    Given the difficulty of achieving a global agreement to cope with the challenges of climate change or even a national resilience programme, an increasing number of initiatives are coming up from the local level for preemptively implementing policies to adapt to climate change or combat it. There are several towns and cities across the world that have taken this line (Copenhagen, Totnes, Vaexjoe, Bristol, etc.) but, as Jean Haentjens shows here, an effective response to climate change requires the development of a genuine strategic vision capable of mobilizing all the actors concerned. For the moment, the towns and cities that have managed to come up with such a vision are few and far between. After a -largely historical- review of the importance of vision in changes of urban paradigm, Jean Haentjens stresses how much twenty-first century eco-urbanism broadens the range of possible solutions to the many issues facing our towns and cities today. But, though digital innovations in fact offer new opportunities at the local level, we should nonetheless be wary of 'technological solutionism': the new technologies are tools which towns and cities can use to their advantage, but to become really 'smart' they have to develop a vision. After presenting a series of established or emerging urban models (the frugal city, the creative city, the leisure city and the eco-metropolis), along with the values and imaginative conceptions that underpin them, this article shows - without being unaware of the potential obstacles - how a town or city can produce and renew its strategic vision to reinvent itself and meet the challenges of today

  10. Hidden loss

    DEFF Research Database (Denmark)

    Kieffer-Kristensen, Rikke; Johansen, Karen Lise Gaardsvig

    2013-01-01

    to participate. RESULTS: All children were affected by their parents' ABI and the altered family situation. The children's expressions led the authors to identify six themes, including fear of losing the parent, distress and estrangement, chores and responsibilities, hidden loss, coping and support. The main......PRIMARY OBJECTIVE: The purpose of this study was to listen to and learn from children showing high levels of post-traumatic stress symptoms after parental acquired brain injury (ABI), in order to achieve an in-depth understanding of the difficulties the children face in their everyday lives...... finding indicates that the children experienced numerous losses, many of which were often suppressed or neglected by the children to protect the ill parents. CONCLUSIONS: The findings indicated that the children seemed to make a special effort to hide their feelings of loss and grief in order to protect...

  11. UNDERSTANDING AND PREVENTING COMPUTER VISION SYNDROME

    OpenAIRE

    REDDY SC; LOH KY

    2008-01-01

    The invention of computer and advancement in information technology has revolutionized and benefited the society but at the same time has caused symptoms related to its usage such as ocular sprain, irritation, redness, dryness, blurred vision and double vision. This cluster of symptoms is known as computer vision syndrome which is characterized by the visual symptoms which result from interaction with computer display or its environment. Three major mechanisms that lead to computer vision syn...

  12. Predictors of vision impairment in Multiple Sclerosis.

    Science.gov (United States)

    Sanchez-Dalmau, Bernardo; Martinez-Lapiscina, Elena H; Pulido-Valdeolivas, Irene; Zubizarreta, Irati; Llufriu, Sara; Blanco, Yolanda; Sola-Valls, Nuria; Sepulveda, Maria; Guerrero, Ana; Alba, Salut; Andorra, Magi; Camos, Anna; Sanchez-Vela, Laura; Alfonso, Veronica; Saiz, Albert; Villoslada, Pablo

    2018-01-01

    Visual impairment significantly alters the quality of life of people with Multiple Sclerosis (MS). The objective of this study was to identify predictors (independent variables) of visual outcomes, and to define their relationship with neurological disability and retinal atrophy when assessed by optical coherence tomography (OCT). We performed a cross-sectional analysis of 119 consecutive patients with MS, assessing vision using high contrast visual acuity (LogMar), 2.5% and 1.25% low contrast visual acuity (Sloan charts), and color vision (Hardy-Rand-Rittler plates). Quality of vision is a patient reported outcome based on an individual's unique perception of his or her vision and was assessed with the Visual Functioning Questionnaire-25 (VFQ-25) with the 10 neuro-ophthalmologic items. MS disability was assessed using the expanded disability status scale (EDSS), the MS functional composite (MSFC) and the brief repetitive battery-neuropsychology (BRB-N). Retinal atrophy was assessed using spectral domain OCT, measuring the thickness of the peripapillar retinal nerve fiber layer (pRNFL) and the volume of the ganglion cell plus inner plexiform layer (GCIPL). The vision of patients with MS was impaired, particularly in eyes with prior optic neuritis. Retinal atrophy (pRNFL and GCIPL) was closely associated with impaired low contrast vision and color vision, whereas the volume of the GCIPL showed a trend (p = 0.092) to be associated with quality of vision. Multiple regression analysis revealed that EDSS was an explanatory variable for high contrast vision after stepwise analysis, GCIPL volume for low contrast vision, and GCIPL volume and EDSS for color vision. The explanatory variables for quality of vision were high contrast vision and color vision. In summary, quality of vision in MS depends on the impairment of high contrast visual acuity and color vision due to the disease.

  13. Peripheral vision benefits spatial learning by guiding eye movements.

    Science.gov (United States)

    Yamamoto, Naohide; Philbeck, John W

    2013-01-01

    The loss of peripheral vision impairs spatial learning and navigation. However, the mechanisms underlying these impairments remain poorly understood. One advantage of having peripheral vision is that objects in an environment are easily detected and readily foveated via eye movements. The present study examined this potential benefit of peripheral vision by investigating whether competent performance in spatial learning requires effective eye movements. In Experiment 1, participants learned room-sized spatial layouts with or without restriction on direct eye movements to objects. Eye movements were restricted by having participants view the objects through small apertures in front of their eyes. Results showed that impeding effective eye movements made subsequent retrieval of spatial memory slower and less accurate. The small apertures also occluded much of the environmental surroundings, but the importance of this kind of occlusion was ruled out in Experiment 2 by showing that participants exhibited intact learning of the same spatial layouts when luminescent objects were viewed in an otherwise dark room. Together, these findings suggest that one of the roles of peripheral vision in spatial learning is to guide eye movements, highlighting the importance of spatial information derived from eye movements for learning environmental layouts.

  14. Female Pattern Hair Loss

    Science.gov (United States)

    Herskovitz, Ingrid; Tosti, Antonella

    2013-01-01

    Context: Female pattern hair loss (FPHL) also known as female androgenetic alopecia is a common condition afflicting millions of women that can be cosmetically disrupting. Prompt diagnosis and treatment are essential for obtaining optimal outcome. This review addresses the clinical presentation of female pattern hair loss, its differential diagnosis and treatment modalities. Evidence Acquisition: A) Diffuse thinning of the crown region with preservation of the frontal hairline (Ludwig’s type) B) The “Christmas tree pattern” where the thinning is wider in the frontal scalp giving the alopecic area a triangular shaped figure resembling a christmas tree. C) Thinning associated with bitemporal recession (Hamilton type). Generally, FPHL is not associated with elevated androgens. Less commonly females with FPHL may have other skin or general signs of hyperandrogenism such as hirsutism, acne, irregular menses, infertility, galactorrhea and insulin resistance. The most common endocrinological abnormality associated with FPHL is polycystic ovarian syndrome (PCOS). Results: The most important diseases to consider in the differential diagnosis of FPHL include Chronic Telogen Effluvium (CTE), Permanent Alopecia after Chemotherapy (PAC), Alopecia Areata Incognito (AAI) and Frontal Fibrosing Alopecia (FFA). This review describes criteria for distinguishing these conditions from FPHL. Conclusions: The only approved treatment for FPHL, which is 2% topical Minoxidil, should be applied at the dosage of 1ml twice day for a minimum period of 12 months. This review will discuss off-label alternative modalities of treatment including 5-alfa reductase inhibitors, antiandrogens, estrogens, prostaglandin analogs, lasers, light treatments and hair transplantation. PMID:24719635

  15. Female pattern hair loss.

    Science.gov (United States)

    Herskovitz, Ingrid; Tosti, Antonella

    2013-10-01

    Female pattern hair loss (FPHL) also known as female androgenetic alopecia is a common condition afflicting millions of women that can be cosmetically disrupting. Prompt diagnosis and treatment are essential for obtaining optimal outcome. This review addresses the clinical presentation of female pattern hair loss, its differential diagnosis and treatment modalities. A) Diffuse thinning of the crown region with preservation of the frontal hairline (Ludwig's type) B) The "Christmas tree pattern" where the thinning is wider in the frontal scalp giving the alopecic area a triangular shaped figure resembling a christmas tree. C) Thinning associated with bitemporal recession (Hamilton type). Generally, FPHL is not associated with elevated androgens. Less commonly females with FPHL may have other skin or general signs of hyperandrogenism such as hirsutism, acne, irregular menses, infertility, galactorrhea and insulin resistance. The most common endocrinological abnormality associated with FPHL is polycystic ovarian syndrome (PCOS). The most important diseases to consider in the differential diagnosis of FPHL include Chronic Telogen Effluvium (CTE), Permanent Alopecia after Chemotherapy (PAC), Alopecia Areata Incognito (AAI) and Frontal Fibrosing Alopecia (FFA). This review describes criteria for distinguishing these conditions from FPHL. The only approved treatment for FPHL, which is 2% topical Minoxidil, should be applied at the dosage of 1ml twice day for a minimum period of 12 months. This review will discuss off-label alternative modalities of treatment including 5-alfa reductase inhibitors, antiandrogens, estrogens, prostaglandin analogs, lasers, light treatments and hair transplantation.

  16. Tubular permanent magnet actuators: cogging forces characterization

    NARCIS (Netherlands)

    Paulides, J.J.H.; Janssen, J.L.G.; Encica, L.; Lomonova, E.A.

    2009-01-01

    Tubular permanent magnet actuators are evermore used in demanding industrial and automotive applications. However, these actuators can suffer from large cogging forces, which have a destabilizing effect on the servo control system and compromise position and speed control accuracy. This paper

  17. Laced permanent magnet quadrupole drift tube magnets

    International Nuclear Information System (INIS)

    Feinberg, B.; Behrsing, G.U.; Halbach, K.; Marks, J.S.; Morrison, M.E.; Nelson, D.H.

    1988-10-01

    A laced permanent magnet quadrupole drift tube magnet has been constructed for a proof-of-principle test. The magnet is a conventional tape-wound quadrupole electromagnet, using iron pole- pieces, with the addition of permanent magnet material (neodymium iron) between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in an asymmetrical saturation curve. Since the polarity of the quadrupole magnets in a drift tube linac is not reversed we can take advantage of this asymmetrical saturation to provide greater focusing strength. The magnet configuration has been optimized and the vanadium permendur poles needed in a conventional quadrupole have been replaced with iron poles. The use of permanent magnet material has allowed us to increase the focusing strength of the magnet by about 20% over that of a conventional tape-wound quadrupole. Comparisons will be made between this magnet and the conventional tape-wound quadrupole. 3 refs., 5 figs

  18. Standards on the permanence of recording materials

    Science.gov (United States)

    Adelstein, Peter Z.

    1996-02-01

    The permanence of recording materials is dependent upon many factors, and these differ for photographic materials, magnetic tape and optical disks. Photographic permanence is affected by the (1) stability of the material, (2) the photographic processing and (3) the storage conditions. American National Standards on the material and the processing have been published for different types of film and standard test methods have been established for color film. The third feature of photographic permanence is the storage requirements and these have been established for photographic film, prints and plates. Standardization on the permanence of electronic recording materials is more complicated. As with photographic materials, stability is dependent upon (1) the material itself and (2) the storage environment. In addition, retention of the necessary (3) hardware and (4) software is also a prerequisite. American National Standards activity in these areas has been underway for the past six years. A test method for the material which determines the life expectancy of CD-ROMs has been standardized. The problems of determining the expected life of magnetic tape have been more formidable but the critical physical properties have been determined. A specification for the storage environment of magnetic tape has been finalized and one on the storage of optical disks is being worked on. Critical but unsolved problems are the obsolescence of both the hardware and the software necessary to read digital images.

  19. resonant inverter supplied interior permanent magnet (ipm)

    African Journals Online (AJOL)

    user

    [5] Zhenyue Hong, “DC-voltage link resonant inverters”, Department of Electrical and. Electronic Engineering University of. Canterbury, New Zealand. [6] Kalyan Kumar Halder, Naruttam Kumar Roy and B.C. Ghosh, “Position Sensorless. Control for an Interior Permanent Magnet. Synchronous Motor SVM Drive with ANN.

  20. 78 FR 14122 - Revocation of Permanent Variances

    Science.gov (United States)

    2013-03-04

    ... Douglas Fir planking had to have at least a 1,900 fiber stress and 1,900,000 modulus of elasticity, while the Yellow Pine planking had to have at least 2,500 fiber stress and 2,000,000 modulus of elasticity... the permanent variances, and affected employees, to submit written data, views, and arguments...

  1. Sexism and Permanent Exclusion from School

    Science.gov (United States)

    Carlile, Anna

    2009-01-01

    Focussing on narratives collected during a two year participant observation research project in the children's services department of an urban local authority, this article addresses the intersection between incidents of permanent exclusion from school and assumptions made on the basis of a young person's gender. The article considers gendered…

  2. Pupil Dilation and Object Permanence in Infants

    Science.gov (United States)

    Sirois, Sylvain; Jackson, Iain R.

    2012-01-01

    This paper examines the relative merits of looking time and pupil diameter measures in the study of early cognitive abilities of infants. Ten-month-old infants took part in a modified version of the classic drawbridge experiment used to study object permanence (Baillargeon, Spelke, & Wasserman, 1985). The study involved a factorial design where…

  3. Risk factors for permanent hypernasality after adenoidectomy ...

    African Journals Online (AJOL)

    Objectives. To investigate the causes of persistent, apparently permanent hypernasal speech following adenoidectomy in 10 subjects without overt cleft palates, and to establish a protocol to be followed before this operation is perfonmed. Design. Retrospective and descriptive design. Participants. Ten subjects, fulfilling the ...

  4. Radionuclides gauges. Gauges designed for permanent installation

    International Nuclear Information System (INIS)

    1987-06-01

    This present norm determines, for radionuclides gauges designed for permanent installation, the characteristics that these gauges should satisfied in their construction and performance to respect the prescriptions. It indicates the testing methods which permit to verify the agreement, gives a classification of gauges and specifies the indications to put on the emitter block [fr

  5. Dovetail spoke internal permanent magnet machine

    Science.gov (United States)

    Alexander, James Pellegrino [Ballston Lake, NY; EL-Refaie, Ayman Mohamed Fawzi [Niskayuna, NY; Lokhandwalla, Murtuza [Clifton Park, NY; Shah, Manoj Ramprasad [Latham, NY; VanDam, Jeremy Daniel [West Coxsackie, NY

    2011-08-23

    An internal permanent magnet (IPM) machine is provided. The IPM machine includes a stator assembly and a stator core. The stator core also includes multiple stator teeth. The stator assembly is further configured with stator windings to generate a stator magnetic field when excited with alternating currents and extends along a longitudinal axis with an inner surface defining a cavity. The IPM machine also includes a rotor assembly and a rotor core. The rotor core is disposed inside the cavity and configured to rotate about the longitudinal axis. The rotor assembly further includes a shaft. The shaft further includes multiple protrusions alternately arranged relative to multiple bottom structures provided on the shaft. The rotor assembly also includes multiple stacks of laminations disposed on the protrusions and dovetailed circumferentially around the shaft. The rotor assembly further includes multiple pair of permanent magnets for generating a magnetic field, which magnetic field interacts with the stator magnetic field to produce a torque. The multiple pair of permanent magnets are disposed between the stacks. The rotor assembly also includes multiple middle wedges mounted between each pair of the multiple permanent magnets.

  6. Permanent downhole seismic sensors in flowing wells

    NARCIS (Netherlands)

    Jaques, P.; Ong, H.; Jupe, A.; Brown, I.; Jansenns, M.

    2003-01-01

    It is generally accepted that the 'Oilfield of the Future' will incorporate distributed permanent downhole seismic sensors in flowing wells. However the effectiveness of these sensors will be limited by the extent to which seismic signals can be discriminated, or de-coupled, from flow induced

  7. Causes of permanent childhood hearing impairment

    NARCIS (Netherlands)

    Korver, Anna M. H.; Admiraal, Ronald J. C.; Kant, Sarina G.; Dekker, Friedo W.; Wever, Capi C.; Kunst, Henricus P. M.; Frijns, Johan H. M.; Oudesluys-Murphy, Anne Marie; Oudesluys-Murphy, A. M.; Korver, A. M. H.; Frijns, J. H. M.; Wever, C. C.; Konings, S.; Beers, W.; Dekker, F. W.; de Vries, J. J. C.; Vossen, A. C. T. M.; Kant, S. G.; van den Akker-van Marle, M. E.; Rieffe, C.; Ens-Dokkum, M. H.; van Straaten, H. L. M.; Uilenburg, N. N.; Elvers, B.; Loeber, G.; Meuwese-Jongejeugd, J.; Maré, M. J.; Van Zanten, G. A.; Goedegebure, A.; Coster, F.; Goverts, S. T.; Admiraal, R. J. C.; Cremers, C. W. R. J.; Kunst, H. P. M.; de Leeuw, M.; Dijkhuizen, J.; Scharloo, M.; Hoeben, D.; Rijpma, G.; Graef, W.; Linschoten, D.; Kuijper, J.; Hof, N. J.; Pans, D.; Jorritsma, F.; van Beurden, M.; ter Huurne, C. T.; Brienesse, P.; Koldewijn, G. J.; Letourneur, K. G.

    2011-01-01

    The causes of Permanent Childhood Hearing Impairment (PCHI) are often quoted as being hereditary in 50%, acquired in 25%, and unknown in 25% of cases. Interest in the causes of PCHI has grown recently due to increasing diagnostic possibilities. We investigated the evidence for the reported

  8. Causes of permanent childhood hearing impairment

    NARCIS (Netherlands)

    Korver, A.M.; Admiraal, R.J.C.; Kant, S.G.; Dekker, F.W.; Wever, C.; Kunst, H.P.M.; Frijns, J.H.; Oudesluys-Murphy, A.M.

    2011-01-01

    INTRODUCTION: The causes of Permanent Childhood Hearing Impairment (PCHI) are often quoted as being hereditary in 50%, acquired in 25%, and unknown in 25% of cases. Interest in the causes of PCHI has grown recently due to increasing diagnostic possibilities. We investigated the evidence for the

  9. Permanent magnet motor technology design and applications

    CERN Document Server

    Gieras, Jacek F

    2009-01-01

    Demonstrates the construction of permanent magnet (PM) motor drives and supplies ready-to-implement solutions to common roadblocks along the way. This book also supplies fundamental equations and calculations for determining and evaluating system performance, efficiency, reliability, and cost. It explores modern computer-aided design of PM motors.

  10. Constant force linear permanent magnet actuators

    NARCIS (Netherlands)

    Paulides, J.J.H.; Encica, L.; Meessen, K.J.; Lomonova, E.A.

    2009-01-01

    In applications, such as vibration isolation, gravity compensation, pick-and-place machines, etc., there is a need for (long-stroke) passive constant force actuators combined with tubular permanent magnet actuators to minimize the power consumption, hence, passively counteract the gravitational

  11. Making a vision document tangible using "vision-tactics-metrics" tables.

    Science.gov (United States)

    Drury, Ivo; Slomski, Carol

    2006-01-01

    We describe a method of making a vision document tangible by attaching specific tactics and metrics to the key elements of the vision. We report on the development and early use of a "vision-tactics-metrics" table in a department of surgery. Use of the table centered the vision in the daily life of the department and its faculty, and facilitated cultural change.

  12. School Vision of Learning: Urban Setting

    Science.gov (United States)

    Guy, Tiffany A.

    2010-01-01

    In this paper, the author develops her school vision of learning. She explains the theories she used to help develop the vision. The author then goes into detail on the methods she will use to make her vision for a school that prepares urban students for a successful life after high school. She takes into account all the stakeholders and how they…

  13. The Vision Thing in Higher Education.

    Science.gov (United States)

    Keller, George

    1995-01-01

    It is argued that while the concept of "vision" in higher education has been met with disdain, criticism is based on misconceptions of vision's nature and role--that vision requires a charismatic administrator and that visionaries are dreamers. Educators and planners are urged to use imaginative thinking to connect the institution's and staff's…

  14. Coaching Peripheral Vision Training for Soccer Athletes

    Science.gov (United States)

    Marques, Nelson Kautzner, Jr.

    2010-01-01

    Brazilian Soccer began developing its current emphasis on peripheral vision in the late 1950s, by initiative of coach of the Canto do Rio Football Club, in Niteroi, Rio de Janeiro, a pioneer in the development of peripheral vision training in soccer players. Peripheral vision training gained world relevance when a young talent from Canto do Rio,…

  15. A Retrospective Study of Causes of Low Vision in Saud Arabia, A Case of Eye World Medical Complex in Riyadh.

    Science.gov (United States)

    Z Alotaibi, Abdullah

    2015-10-20

    Vision is the ability of seeing with a definite understanding of features, color and contrast, and to distinguish between objects visually. In the year 1999, the World Health Organization (WHO) and the International Agency for the Prevention of Blindness formulated a worldwide project for the eradication of preventable loss of sight with the subject of "Vision 2020: the Right to Sight". This global program aims to eradicate preventable loss of sight by the year 2020. This study was conducted to determine the main causes of low vision in Saudi Arabia and also to assess their visual improvement after using low vision aids (LVD).The study is a retrospective study and was conducted in low vision clinic at Eye World Medical Complex in Riyadh, Saudi Arabia. The file medical record of 280 patients attending low vision clinics from February 2008 to June 2010 was included. A data sheet was filled which include: age, gender, cause of low vision, unassisted visual acuity for long distances and short distances, low vision devices needed for long distances and short distances that provides best visual acuity. The result shows that the main cause of low vision was Optic atrophy (28.9%). Retinitis pigmentosa was the second cause of low vision, accounting for 73 patients (26%) followed by Diabetic retinopathy and Macular degeneration with 44 patients (15.7%) and 16 patients (5.7%) respectively. Inter family marriage could be one of the main causes of low vision. Public awareness should be embarked on for enlightenment on ocular diseases result in consanguineous marriage. Also, it is an important issue to start establishing low vision clinics in order to improve the situation.

  16. Permanent isolation surface barrier development plan

    International Nuclear Information System (INIS)

    Wing, N.R.

    1994-01-01

    The exhumation and treatment of wastes may not always be the preferred alternative in the remediation of a waste site. In-place disposal alternatives, under certain circumstances, may be the most desirable alternatives to use in the protection of human health and the environment. The implementation of an in-place disposal alternative will likely require some type of protective covering that will provide long-term isolation of the wastes from the accessible environment. Even if the wastes are exhumed and treated, a long-term barrier may still be needed to adequately dispose of the treated wastes or any remaining waste residuals. Currently, no open-quotes provenclose quotes long-term barrier is available. The Hanford Site Permanent Isolation Surface Barrier Development Program (BDP) was organized to develop the technology needed to provide a long-term surface barrier capability for the Hanford Site. The permanent isolation barrier technology also could be used at other sites. Permanent isolation barriers use engineered layers of natural materials to create an integrated structure with redundant protective features. Drawings of conceptual permanent isolation surface barriers are shown. The natural construction materials (e.g., fine soil, sand, gravel, riprap, asphalt) have been selected to optimize barrier performance and longevity. The objective of current designs is to use natural materials to develop a maintenance-free permanent isolation surface barrier that isolates wastes for a minimum of 1,000 years by limiting water drainage to near-zero amounts; reducing the likelihood of plant, animal, and human intrusion; controlling the exhalation of noxious gases; and minimizing erosion-related problems

  17. Permanent isolation surface barrier development plan

    Energy Technology Data Exchange (ETDEWEB)

    Wing, N.R.

    1994-01-01

    The exhumation and treatment of wastes may not always be the preferred alternative in the remediation of a waste site. In-place disposal alternatives, under certain circumstances, may be the most desirable alternatives to use in the protection of human health and the environment. The implementation of an in-place disposal alternative will likely require some type of protective covering that will provide long-term isolation of the wastes from the accessible environment. Even if the wastes are exhumed and treated, a long-term barrier may still be needed to adequately dispose of the treated wastes or any remaining waste residuals. Currently, no {open_quotes}proven{close_quotes} long-term barrier is available. The Hanford Site Permanent Isolation Surface Barrier Development Program (BDP) was organized to develop the technology needed to provide a long-term surface barrier capability for the Hanford Site. The permanent isolation barrier technology also could be used at other sites. Permanent isolation barriers use engineered layers of natural materials to create an integrated structure with redundant protective features. Drawings of conceptual permanent isolation surface barriers are shown. The natural construction materials (e.g., fine soil, sand, gravel, riprap, asphalt) have been selected to optimize barrier performance and longevity. The objective of current designs is to use natural materials to develop a maintenance-free permanent isolation surface barrier that isolates wastes for a minimum of 1,000 years by limiting water drainage to near-zero amounts; reducing the likelihood of plant, animal, and human intrusion; controlling the exhalation of noxious gases; and minimizing erosion-related problems.

  18. Irradiated radiation dose measurements of multilayer mirrors and permanent magnets used at FELI facilities

    International Nuclear Information System (INIS)

    Wakisaka, K.; Tongu, H.; Okuma, S.; Oshita, E.; Wakita, K.; Takii, T.; Tomimasu, Takio

    1997-01-01

    Recently the operation time of the free electron laser (FEL) user's facilities is close on three thousand hours per year. Cavity mirrors of their optical resonators and permanent magnets of their undulators are used under high intensity radiation field along their high current electron beam lines. Among these mirrors and permanent magnets, multilayer mirrors and Nd-Fe-B permanent magnets are not so strong against radiation damage compared with Au-coated copper mirrors and Sm-Co permanent magnets. A radiation damage on Ta 2 O 5 /SiO 2 mirrors was found for the first time after about fifty hours visible FEL operation at the FELI. The damage is due to irradiated bremsstrahlung and intracavity FEL. However, radiation damages on Nd-Fe-B permanent magnets were already reported compared with Sm-Co ones using high energy neutrons, protons, deuterons and 60 Coγ-rays. Mixed irradiation effects of 85-MeV electrons, bremsstrahlung and 60 Coγ-rays and of 17-MeV electrons and 60 Coγ-rays were also studied. The latest results show that the magnetic flux loss of Nd-Fe-B is 2% at an absorbed dose of 10 MGy. The present work was carried out to study the irradiated dose distributions near the multilayer mirrors and Nd-Fe-B permanent magnets with thermoluminescence dosimeters (TLDs). The irradiated dose to the cavity mirrors used in Linac-based FEL experiment is estimated to be 0.3 MGray for fifty hours irradiation. The irradiated dose to the Nd-Fe-B magnets is estimated to be 16 MGray for 2 thousand hours operation. The decrease of their magnetic flux due to 16 MGray is estimated to be about 3%. These dose monitorings are useful to reduce irradiated dosages to the mirrors and the permanent magnets as low as possible and to estimate their safety lifetimes. (author)

  19. Temporary effects of alcohol on color vision

    Science.gov (United States)

    Geniusz, Maciej K.; Geniusz, Malwina; Szmigiel, Marta; Przeździecka-Dołyk, Joanna

    2017-09-01

    The color vision has been described as one to be very sensitive to the intake of several chemicals. The present research reviews the published literature that is concerned with color vision impairment due to alcohol. Most of this research considers people under long-term effects of alcohol. However, there is little information about temporary effects of alcohol on color vision. A group of ten volunteers aged 18-40 was studied. During the study levels of alcohol in the body were tested with a standard breathalyzer while color vision were studied using Farnsworth Munsell 100 Hue Color Vision Tests. Keywords: Col

  20. VISION User Guide - VISION (Verifiable Fuel Cycle Simulation) Model

    International Nuclear Information System (INIS)

    Jacobson, Jacob J.; Jeffers, Robert F.; Matthern, Gretchen E.; Piet, Steven J.; Baker, Benjamin A.; Grimm, Joseph

    2009-01-01

    The purpose of this document is to provide a guide for using the current version of the Verifiable Fuel Cycle Simulation (VISION) model. This is a complex model with many parameters; the user is strongly encouraged to read this user guide before attempting to run the model. This model is an R and D work in progress and may contain errors and omissions. It is based upon numerous assumptions. This model is intended to assist in evaluating 'what if' scenarios and in comparing fuel, reactor, and fuel processing alternatives at a systems level for U.S. nuclear power. The model is not intended as a tool for process flow and design modeling of specific facilities nor for tracking individual units of fuel or other material through the system. The model is intended to examine the interactions among the components of a fuel system as a function of time varying system parameters; this model represents a dynamic rather than steady-state approximation of the nuclear fuel system. VISION models the nuclear cycle at the system level, not individual facilities, e.g., 'reactor types' not individual reactors and 'separation types' not individual separation plants. Natural uranium can be enriched, which produces enriched uranium, which goes into fuel fabrication, and depleted uranium (DU), which goes into storage. Fuel is transformed (transmuted) in reactors and then goes into a storage buffer. Used fuel can be pulled from storage into either separation of disposal. If sent to separations, fuel is transformed (partitioned) into fuel products, recovered uranium, and various categories of waste. Recycled material is stored until used by its assigned reactor type. Note that recovered uranium is itself often partitioned: some RU flows with recycled transuranic elements, some flows with wastes, and the rest is designated RU. RU comes out of storage if needed to correct the U/TRU ratio in new recycled fuel. Neither RU nor DU are designated as wastes. VISION is comprised of several Microsoft