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Sample records for acuity remained unchanged

  1. Attempted Suicide Rates in U.S. Remain Unchanged

    MedlinePlus

    ... U.S. Remain Unchanged Men more often resorted to violent means, while women turned to poisoning, drowning, study ... likely to attempt suicide, but males used more violent methods. And all attempts were most common in ...

  2. Long-Term Functional Dynamics of an Aphidophagous Coccinellid Community Remain Unchanged despite Repeated Invasions

    PubMed Central

    Bahlai, Christine A.; Colunga-Garcia, Manuel; Gage, Stuart H.; Landis, Douglas A.

    2013-01-01

    Aphidophagous coccinellids (ladybeetles) are important providers of herbivore suppression ecosystem services. In the last 30 years, the invasion of exotic coccinellid species, coupled with observed declines in native species, has led to considerable interest in the community dynamics and ecosystem function of this guild. Here we examined a 24-year dataset of coccinellid communities in nine habitats in southwestern Michigan for changes in community function in response to invasion. Specifically we analyzed their temporal population dynamics and species diversity, and we modeled the community’s potential to suppress pests. Abundance of coccinellids varied widely between 1989 and 2012 and became increasingly exotic-dominated. More than 71% of 57,813 adult coccinellids captured over the 24-year study were exotic species. Shannon diversity increased slightly over time, but herbivore suppression potential of the community remained roughly constant over the course of the study. However, both Shannon diversity and herbivore suppression potential due to native species declined over time in all habitats. The relationship between Shannon diversity and herbivore suppression potential varied with habitat type: a positive relationship in forest and perennial habitats, but was uncorrelated in annual habitats. This trend may have been because annual habitats were dominated by a few, highly voracious exotic species. Our results indicated that although the composition of the coccinellid community in southwestern Michigan has changed dramatically in the past several decades, its function has remained relatively unchanged in both agricultural and natural habitats. While this is encouraging from the perspective of pest management, it should be noted that losses of one of the dominant exotic coccinellids could result in a rapid decline in pest suppression services if the remaining community is unable to respond. PMID:24349505

  3. Mutation allele burden remains unchanged in chronic myelomonocytic leukaemia responding to hypomethylating agents

    PubMed Central

    Merlevede, Jane; Droin, Nathalie; Qin, Tingting; Meldi, Kristen; Yoshida, Kenichi; Morabito, Margot; Chautard, Emilie; Auboeuf, Didier; Fenaux, Pierre; Braun, Thorsten; Itzykson, Raphael; de Botton, Stéphane; Quesnel, Bruno; Commes, Thérèse; Jourdan, Eric; Vainchenker, William; Bernard, Olivier; Pata-Merci, Noemie; Solier, Stéphanie; Gayevskiy, Velimir; Dinger, Marcel E.; Cowley, Mark J.; Selimoglu-Buet, Dorothée; Meyer, Vincent; Artiguenave, François; Deleuze, Jean-François; Preudhomme, Claude; Stratton, Michael R.; Alexandrov, Ludmil B.; Padron, Eric; Ogawa, Seishi; Koscielny, Serge; Figueroa, Maria; Solary, Eric

    2016-01-01

    The cytidine analogues azacytidine and 5-aza-2'-deoxycytidine (decitabine) are commonly used to treat myelodysplastic syndromes, with or without a myeloproliferative component. It remains unclear whether the response to these hypomethylating agents results from a cytotoxic or an epigenetic effect. In this study, we address this question in chronic myelomonocytic leukaemia. We describe a comprehensive analysis of the mutational landscape of these tumours, combining whole-exome and whole-genome sequencing. We identify an average of 14±5 somatic mutations in coding sequences of sorted monocyte DNA and the signatures of three mutational processes. Serial sequencing demonstrates that the response to hypomethylating agents is associated with changes in DNA methylation and gene expression, without any decrease in the mutation allele burden, nor prevention of new genetic alteration occurence. Our findings indicate that cytosine analogues restore a balanced haematopoiesis without decreasing the size of the mutated clone, arguing for a predominantly epigenetic effect. PMID:26908133

  4. Mutation allele burden remains unchanged in chronic myelomonocytic leukaemia responding to hypomethylating agents

    SciTech Connect

    Merlevede, Jane; Droin, Nathalie; Qin, Tingting; Meldi, Kristen; Yoshida, Kenichi; Morabito, Margot; Chautard, Emilie; Auboeuf, Didier; Fenaux, Pierre; Braun, Thorsten; Itzykson, Raphael; de Botton, Stephane; Quesnel, Bruno; Commes, Therese; Jourdan, Eric; Vainchenker, William; Bernard, Olivier; Pata-Merci, Noemie; Solier, Stephanie; Gayevskiy, Velimir; Dinger, Marcel E.; Cowley, Mark J.; Selimoglu-Buet, Dorothee; Meyer, Vincent; Artiguenave, Francois; Deleuze, Jean -Francois; Preudhomme, Claude; Stratton, Michael R.; Alexandrov, Ludmil B.; Padron, Eric; Ogawa, Seishi; Koscielny, Serge; Figueroa, Maria; Solary, Eric

    2016-02-24

    The cytidine analogues azacytidine and 5-aza-2’-deoxycytidine (decitabine) are commonly used to treat myelodysplastic syndromes, with or without a myeloproliferative component. It remains unclear whether the response to these hypomethylating agents results from a cytotoxic or an epigenetic effect. In this study, we address this question in chronic myelomonocytic leukaemia. We describe a comprehensive analysis of the mutational landscape of these tumours, combining whole-exome and whole-genome sequencing. We identify an average of 14 ± 5 somatic mutations in coding sequences of sorted monocyte DNA and the signatures of three mutational processes. Serial sequencing demonstrates that the response to hypomethylating agents is associated with changes in DNA methylation and gene expression, without any decrease in the mutation allele burden, nor prevention of new genetic alteration occurence. Lastly, our findings indicate that cytosine analogues restore a balanced haematopoiesis without decreasing the size of the mutated clone, arguing for a predominantly epigenetic effect.

  5. Mutation allele burden remains unchanged in chronic myelomonocytic leukaemia responding to hypomethylating agents

    DOE PAGES

    Merlevede, Jane; Droin, Nathalie; Qin, Tingting; ...

    2016-02-24

    The cytidine analogues azacytidine and 5-aza-2’-deoxycytidine (decitabine) are commonly used to treat myelodysplastic syndromes, with or without a myeloproliferative component. It remains unclear whether the response to these hypomethylating agents results from a cytotoxic or an epigenetic effect. In this study, we address this question in chronic myelomonocytic leukaemia. We describe a comprehensive analysis of the mutational landscape of these tumours, combining whole-exome and whole-genome sequencing. We identify an average of 14 ± 5 somatic mutations in coding sequences of sorted monocyte DNA and the signatures of three mutational processes. Serial sequencing demonstrates that the response to hypomethylating agents ismore » associated with changes in DNA methylation and gene expression, without any decrease in the mutation allele burden, nor prevention of new genetic alteration occurence. Lastly, our findings indicate that cytosine analogues restore a balanced haematopoiesis without decreasing the size of the mutated clone, arguing for a predominantly epigenetic effect.« less

  6. Improved Acuity and Dexterity but Unchanged Touch and Pain Thresholds following Repetitive Sensory Stimulation of the Fingers

    PubMed Central

    Kowalewski, Rebecca; Kattenstroth, Jan-Christoph; Kalisch, Tobias; Dinse, Hubert R.

    2012-01-01

    Neuroplasticity underlies the brain's ability to alter perception and behavior through training, practice, or simply exposure to sensory stimulation. Improvement of tactile discrimination has been repeatedly demonstrated after repetitive sensory stimulation (rSS) of the fingers; however, it remains unknown if such protocols also affect hand dexterity or pain thresholds. We therefore stimulated the thumb and index finger of young adults to investigate, besides testing tactile discrimination, the impact of rSS on dexterity, pain, and touch thresholds. We observed an improvement in the pegboard task where subjects used the thumb and index finger only. Accordingly, stimulating 2 fingers simultaneously potentiates the efficacy of rSS. In fact, we observed a higher gain of discrimination performance as compared to a single-finger rSS. In contrast, pain and touch thresholds remained unaffected. Our data suggest that selecting particular fingers modulates the efficacy of rSS, thereby affecting processes controlling sensorimotor integration. PMID:22315693

  7. The number of cells expressing the myelin-supporting oligodendrocyte marker PLP-exon 3b remains unchanged in Wallerian degeneration.

    PubMed

    Li, G; Blakemore, W F

    2004-08-01

    Following spinal cord trauma there is controversy as to whether myelin-supporting oligodendrocytes at a distance from areas of spinal cord damage undergo apoptosis. To examine the response of oligodendrocytes to axon degeneration, we counted the number of oligodendrocytes and oligodendrocyte precursors in the dorsal funiculi during the course of Wallerian degeneration. Axons were disrupted at T13 and the number of labelled cells in the dorsal funiculi counted at T12, 4 days and 2, 4, and 8 weeks after injury using riboprobes to exon-3b of the PLP gene whose expression is considered to restricted to myelin-supporting oligodendrocytes, PDGFRalpha which is regarded as a marker of oligodendrocyte precursors, and MOG a marker previously used to identify myelin-supporting oligodendrocytes. We found that the number of PLP-exon-3b labelled cells remained constant during the course of Wallerian degeneration while the number of cells labelled with the riboprobes to PDGFRalpha and MOG increased. Significantly the number of MOG-positive cells was increased at times when the number of PDGFRalpha labelled cells was highest. The number of PDGFRalpha labelled cells decreased with time while the number PLP-exon-3b labelled cells remained constant. It is therefore possible that the apoptotic oligodendrocytes identified in previous studies could represent degenerating oligodendrocyte precursors or their progeny rather than degenerating myelin-supporting oligodendrocytes.

  8. Experimental warming in a dryland community reduced plant photosynthesis and soil CO2 efflux although the relationship between the fluxes remained unchanged

    USGS Publications Warehouse

    Wertin, Timothy M.; Belnap, Jayne; Reed, Sasha C.

    2016-01-01

    1. Drylands represent our planet's largest terrestrial biome and, due to their extensive area, maintain large stocks of carbon (C). Accordingly, understanding how dryland C cycling will respond to climate change is imperative for accurately forecasting global C cycling and future climate. However, it remains difficult to predict how increased temperature will affect dryland C cycling, as substantial uncertainties surround the potential responses of the two main C fluxes: plant photosynthesis and soil CO2 efflux. In addition to a need for an improved understanding of climate effects on individual dryland C fluxes, there is also notable uncertainty regarding how climate change may influence the relationship between these fluxes.2. To address this important knowledge gap, we measured a growing season's in situphotosynthesis, plant biomass accumulation, and soil CO2 efflux of mature Achnatherum hymenoides (a common and ecologically important C3 bunchgrass growing throughout western North America) exposed to ambient or elevated temperature (+2°C above ambient, warmed via infrared lamps) for three years.3. The 2°C increase in temperature caused a significant reduction in photosynthesis, plant growth, and soil CO2 efflux. Of important note, photosynthesis and soil respiration appeared tightly coupled and the relationship between these fluxes was not altered by the elevated temperature treatment, suggesting C fixation's strong control of both above-ground and below-ground dryland C cycling. Leaf water use efficiency was substantially increased in the elevated temperature treatment compared to the control treatment.4. Taken together, our results suggest notable declines in photosynthesis with relatively subtle warming, reveal strong coupling between above- and below-ground C fluxes in this dryland, and highlight temperature's strong effect on fundamental components of dryland C and water cycles.

  9. The neurology of visual acuity.

    PubMed

    Frisén, L

    1980-09-01

    A series of patients with well defined lesions of various parts of the visual pathways was studied in an attempt to iluminate the neuropathophysiology of visual acuity. Acuity was found to remain normal in all cases with unilateral retrochiasmal lesions, including those of the optic tract. Bilateral retrochiasmal lesions involving the foveal nerve fibres on both sides impaired acuity to the same degree in both eyes. Lateral chiasmal lesions regularly produced impaired acuity in the ipsilateral eye. Midchiasmal lesions commonly led to an impairment of visual acuity in both eyes, usually asymmetrically, and roughly proportionate to the severity of the visual field defect. Compression optic neuropathy was found to reduce acuity in rough proportion to the severity of compression. It was concluded that acuity remains normal as long as either the crossing or the non-crossing neural outflow from the retinal fovea remains intact: acuity fails only when both sets of nerve fibres are compromised. A properly executed acuity test seems to be a powerful tool for detecting such conditions. The lower limit of normal acuity should never be set below 1.0 or 20/20: even this level is clearly subnormal in many subjects.

  10. Contour interaction for foveal acuity targets at different luminances.

    PubMed

    Bedell, Harold E; Siderov, John; Waugh, Sarah J; Zemanová, Romana; Pluháček, František; Musilová, Lenka

    2013-08-30

    Single-letter visual acuity is impaired by nearby flanking stimuli, a phenomenon known as contour interaction. We showed previously that when foveal acuity is degraded by a reduction of letter contrast, both the magnitude and angular spatial extent of foveal contour interaction remain unchanged. In this study, we asked whether contour interaction also remains unchanged when foveal visual acuity is degraded by a reduction of the target's background luminance. Percent correct letter identification was measured for isolated, near-threshold black Sloan letters and for letters surrounded by 4 flanking bars in 10 normal observers, 5 at Anglia Ruskin University, UK (ARU) and 5 at Palacky University, Czech Republic (PU). A stepwise reduction in the background luminance over 3 log units resulted in an approximately threefold increase in the near-threshold letter size. At each background luminance, black flanking bars with a width equal to 1 letter stroke were presented at separations between approximately 0.45 and 4.5 min arc (ARU) or 0.32 and 3.2 min arc (PU). The results indicate that the angular extent of contour interaction remains unchanged at approximately 4 min arc at all background luminances. On the other hand, the magnitude of contour interaction decreases systematically as luminance is reduced, from approximately a 50% reduction to a 30% reduction in percent correct. The constant angular extent and decreasing magnitude of contour interaction with a reduction of background luminance suggest foveal contour interaction is mediated by luminance-dependent lateral inhibition within a fixed angular region.

  11. Visual acuity test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003396.htm Visual acuity test To use the sharing features on this page, please enable JavaScript. The visual acuity test is used to determine the smallest ...

  12. Factors Affecting Crowded Acuity: Eccentricity and Contrast

    PubMed Central

    Coates, Daniel R.; Chin, Jeremy M.; Chung, Susana T. L.

    2013-01-01

    Purpose Acuity measurement is a fundamental method to assess visual performance in the clinic. Little is known about how acuity measured in the presence of neighboring letters, as in the case of letter charts, changes with contrast and with non-foveal viewing. This information is crucial for acuity measurement using low-contrast charts and when patients cannot use their fovea. In this study, we evaluated how optotype acuity, with and without flankers, is affected by contrast and eccentricity. Methods Five young adults with normal vision identified the orientation of a Tumbling-E alone or in the presence of four flanking Tumbling-Es. Edge-to-edge letter spacing ranged from 1 to 20 bar widths. Stimuli were presented on a white background for 150 ms with Weber contrast ranging from −2.5% to −99%. Flankers had the same size and contrast as the target. Testings were performed at the fovea, 3, 5 and 10 degrees in the inferior visual field. Results When plotted as a function of letter spacing, acuity remains unaffected by the presence of flankers until the flankers are within the critical spacing, which averages an edge-to-edge spacing of 4.4 bar widths at the fovea, and approximately 16 bar widths at all three eccentricities. Critical spacing decreases with a reduction in contrast. When plotted as a function of contrast, acuity only worsens when the contrast falls below approximately 24% at the fovea and 17% in the periphery, for flanked and unflanked conditions alike. Conclusions The letter spacing on conventional letter charts exceeds the critical spacing for acuity measurement at the fovea, at all contrast levels. Thus these charts are appropriate for assessing foveal acuity. In the periphery, the critical spacing is larger than the letter spacing on conventional charts. Consequently, these charts may underestimate the acuity measured in the periphery due to the effects of crowding. PMID:23770657

  13. Visual acuity and test performance.

    PubMed

    Heron, E; Zytkoskee, A

    1981-02-01

    Evaluation of scholastic achievement (American College Testing Service) test scores confirms previous reports that persons with poor visual acuity perform better on these tests than individuals with normal or superior acuity.

  14. 38 CFR 4.76 - Visual acuity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Visual acuity. 4.76... DISABILITIES Disability Ratings The Organs of Special Sense § 4.76 Visual acuity. (a) Examination of visual acuity. Examination of visual acuity must include the central uncorrected and corrected visual acuity...

  15. Clean Air Act likely to remain unchanged until new Congress takes office in '83

    SciTech Connect

    Not Available

    1982-05-01

    Political differences between the Senate's effort to fine-tune the Clean Air Act and the House effort to cut back regulations will probably delay reauthorization until next year. Politically vulnerable House members are aware of the jobs versus clean air issue in their debate. The more-modest Senate goals will make compromise difficult. The major issues are automobile emissions, non-attainment penalties, acid rain, and prevention of significant deterioration (PSD) requirements. Reforms at the Environmental Protection Agency will be minimal while Congress debates, although EPA will try to expedite the emission-trading and bubble concepts. The US-Canadian acid rain study is experiencing problems because of confused loyalties, but former chairman Robert Sugarman suggests the US should meet Canada's goal of reducing sulfur dioxide emissions 50% as insurance while continuing research efforts. (DCK)

  16. Visual Acuity and the Eye.

    ERIC Educational Resources Information Center

    Beynon, J.

    1985-01-01

    Shows that visual acuity is a function of the structure of the eye and that its limit is set by the structure of the retina, emphasizing the role of lens aberrations and difraction on image quality. Also compares human vision with that of other vertebrates and insects. (JN)

  17. Phenomenological model of visual acuity

    NASA Astrophysics Data System (ADS)

    Gómez-Pedrero, José A.; Alonso, José

    2016-12-01

    We propose in this work a model for describing visual acuity (V) as a function of defocus and pupil diameter. Although the model is mainly based on geometrical optics, it also incorporates nongeometrical effects phenomenologically. Compared to similar visual acuity models, the proposed one considers the effect of astigmatism and the variability of best corrected V among individuals; it also takes into account the accommodation and the "tolerance to defocus," the latter through a phenomenological parameter. We have fitted the model to the V data provided in the works of Holladay et al. and Peters, showing the ability of this model to accurately describe the variation of V against blur and pupil diameter. We have also performed a comparison between the proposed model and others previously published in the literature. The model is mainly intended for use in the design of ophthalmic compensations, but it can also be useful in other fields such as visual ergonomics, design of visual tests, and optical instrumentation.

  18. Preschool visual acuity screening tests.

    PubMed Central

    Friendly, D S

    1978-01-01

    The purpose of the study was to evaluate the relative merits of two screening tests used for visual acuity assessment of preschool children. The tests that were compared were the Good-Lite Company versions of the E-Test and of the STYCAR (Screening Test for Young Children and Retardates). The former is the most popular method for evaluating central acuity in young children in this nation; the STYCAR is a relatively new letter-matching-test developed in England, where it is widely employed. The E-Test poses left-right orientation problems which are eliminated by the symmetrical letters H, T, O and V utilized in the Letter-Matching-Test. Both visual acuity tests were administered on two separate occasions by personnel from the Prevention of Blindness Society of Metropolitan Washington to 633 preschool children in Washington, D.C. By random selection, 150 of the children received the E-Test at both sessions, 162 children received the Letter-Matching-Test at both sessions, 160 chilt athe the second session, and 161 children received the Letter-Matching-Test at the first session and the E-Test at the second session. The author medically examined the eyes of 408 of the 633 children without knowledge of which test had been initially administered. Statistical analysis of the data obtained from the study indicated that the Letter-Matching-Test was significantly better in terms of testability rates, group and individual instruction time, and performance time. The E-Test was more reliable in terms of test-retest acuity scores and was also more valid in terms of agreement between pass-fail results obtained at the first screening session and two levels of pass-fail refraction criteria. Images FIGURE 4 FIGURE 5 FIGURE 7 A FIGURE 7 B FIGURE 9 A FIGURE 9 B PMID:754379

  19. Prediction of Visual Acuity from Wavefront Aberrations

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B. (Inventor); Ahumada, Albert J. (Inventor)

    2013-01-01

    A method for generating a visual acuity metric, based on wavefront aberrations (WFAs), associated with a test subject and representing classes of imperfections, such as defocus, astigmatism, coma and spherical aberrations, of the subject's visual system. The metric allows choices of different image template, can predict acuity for different target probabilities, can incorporate different and possibly subject-specific neural transfer functions, can predict acuity for different subject templates, and incorporates a model of the optotype identification task.

  20. Vernier acuity through night vision goggles.

    PubMed

    Rabin, J

    1993-08-01

    Night vision goggles (NVG's) are being used increasingly in military and civilian environments. Despite the use of these devices, relatively few tests exist to assess visual performance through NVG's. Hyperacuity tasks may provide a sensitive index of performance through night vision devices. In this study, grating vernier acuity was measured through NVG's. As reported previously, a power law relation was observed between vernier acuity and stimulus contrast. Comparison of vernier acuity with and without NVG's indicated that performance is limited by the contrast transfer of the device. Vernier acuity measurements can be used to assess the quality of vision and quantity of contrast transferred through night vision devices.

  1. 38 CFR 4.76 - Visual acuity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... distance and near vision using Snellen's test type or its equivalent. (b) Evaluation of visual acuity. (1) Evaluate central visual acuity on the basis of corrected distance vision with central fixation, even if a central scotoma is present. However, when the lens required to correct distance vision in the poorer...

  2. 38 CFR 4.76 - Visual acuity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... distance and near vision using Snellen's test type or its equivalent. (b) Evaluation of visual acuity. (1) Evaluate central visual acuity on the basis of corrected distance vision with central fixation, even if a central scotoma is present. However, when the lens required to correct distance vision in the poorer...

  3. 38 CFR 4.76 - Visual acuity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... distance and near vision using Snellen's test type or its equivalent. (b) Evaluation of visual acuity. (1) Evaluate central visual acuity on the basis of corrected distance vision with central fixation, even if a central scotoma is present. However, when the lens required to correct distance vision in the poorer...

  4. 38 CFR 4.76 - Visual acuity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... distance and near vision using Snellen's test type or its equivalent. (b) Evaluation of visual acuity. (1) Evaluate central visual acuity on the basis of corrected distance vision with central fixation, even if a central scotoma is present. However, when the lens required to correct distance vision in the poorer...

  5. Influence of Motion Smear on Visual Acuity in Simulated Infantile Nystagmus

    PubMed Central

    Chung, Susana T. L.; LaFrance, Martin W.; Bedell, Harold E.

    2011-01-01

    Purpose In persons with infantile nystagmus (IN), visual acuity correlates with the duration of the foveation period of the nystagmus waveform, i.e., when the retinal image is on or near the fovea and moves with low velocity. In this study, we asked how acuity is affected by the non-foveating phases of the nystagmus waveform, when the velocity of retinal image motion is substantially higher. Methods Visual acuity was measured in three normal observers for high-contrast, 4-orientation Ts, presented during image motion that simulated either the whole jerk-IN waveform (whole-waveform) or only the foveation periods of the IN waveform (foveation-only). Simulated foveation durations ranged from 20 to 120 ms. For both motion waveforms, we displayed the acuity target for different number of cycles to examine if acuity benefits from multiple presentations of the stimulus. Results As expected, visual acuity improves with longer simulated foveation durations in both the whole-waveform and foveation-only conditions. Acuity is consistently better (by approximately 0.1 logMAR) in the foveation-only than the whole-waveform condition, indicating that the high-velocity image motion during the simulated IN waveform has a detrimental effect. This difference in acuity between the two waveform conditions increases with the number of cycles, apparently because summation occurs across cycles in the foveation-only condition but not in the whole-waveform condition. Conclusions In normal observers, visual acuity in the presence of a simulated nystagmus waveform is limited not only by the duration of the foveation periods, but also by the non-foveating phases of the waveform. However, because persons with IN report little or no motion smear in association with their nystagmus, it remains unclear whether the rapid retinal image motion during the non-foveating phases of the nystagmus waveform generates a similar degradation of visual acuity in IN. PMID:21200353

  6. Ultrafine spatial acuity of blind expert human echolocators

    PubMed Central

    Puri, Amrita; Whitney, David

    2013-01-01

    Echolocating organisms represent their external environment using reflected auditory information from emitted vocalizations. This ability, long known in various non-human species, has also been documented in some blind humans as an aid to navigation, as well as object detection and coarse localization. Surprisingly, our understanding of the basic acuity attainable by practitioners—the most fundamental underpinning of echoic spatial perception—remains crude. We found that experts were able to discriminate horizontal offsets of stimuli as small as ~1.2° auditory angle in the frontomedial plane, a resolution approaching the maximum measured precision of human spatial hearing and comparable to that found in bats performing similar tasks. Furthermore, we found a strong correlation between echolocation acuity and age of blindness onset. This first measure of functional spatial resolution in a population of expert echolocators demonstrates precision comparable to that found in the visual periphery of sighted individuals. PMID:22101568

  7. Stereopsis and positional acuity under dark adaptation.

    PubMed

    Livingstone, M S; Hubel, D H

    1994-03-01

    Though experience tells us we can perceive depth in dim light, it is not so obvious that one of the chief mechanisms for depth perception, stereopsis, is possible under scotopic conditions. The only studies on human stereopsis in the dark adapted state seem to be those of Nagel [(1902) Zeitschrift für Psychologie, 27, 264-266] and Mueller and Lloyd [(1948) Proceedings of the National Academy of Science, U.S.A., 34, 223-227], both of which used real objects or line stereograms. We tested stereopsis using both random-dot and line stereograms and, in agreement with these studies, found that stereopsis is indeed possible in dark adaptation. We also measured stereo acuity and positional acuity (both of which are examples of hyperacuity) and compared these with grating acuity at several levels of light and dark adaptation. At all illumination levels tested, acuities for stereopsis and relative line position were both higher than for grating acuity. As light levels decreased, positional and grating acuity declined in parallel fashion, whereas stereoacuity declined more steeply.

  8. Three-dimensional Invasion of Human Glioblastoma Cells Remains Unchanged by X-ray and Carbon Ion Irradiation In Vitro

    SciTech Connect

    Eke, Iris; Storch, Katja; Kaestner, Ina; Vehlow, Anne; Faethe, Christina; Mueller-Klieser, Wolfgang; Taucher-Scholz, Gisela; Temme, Achim; Schackert, Gabriele

    2012-11-15

    Purpose: Cell invasion represents one of the major determinants that treatment has failed for patients suffering from glioblastoma. Contrary findings have been reported for cell migration upon exposure to ionizing radiation. Here, the migration and invasion capability of glioblastoma cells on and in collagen type I were evaluated upon irradiation with X-rays or carbon ions. Methods and Materials: Migration on and invasion in collagen type I were evaluated in four established human glioblastoma cell lines exposed to either X-rays or carbon ions. Furthermore, clonogenic radiation survival, proliferation (5-bromo-2-deoxyuridine positivity), DNA double-strand breaks ({gamma}H2AX/53BP1-positive foci), and expression of invasion-relevant proteins (eg, {beta}1 integrin, FAK, MMP2, and MMP9) were explored. Migration and invasion assays for primary glioblastoma cells also were carried out with X-ray irradiation. Results: Neither X-ray nor carbon ion irradiation affected glioblastoma cell migration and invasion, a finding similarly observed in primary glioblastoma cells. Intriguingly, irradiated cells migrated unhampered, despite DNA double-strand breaks and reduced proliferation. Clonogenic radiation survival was increased when cells had contact with extracellular matrix. Specific inhibition of the {beta}1 integrin or proliferation-associated signaling molecules revealed a critical function of JNK, PI3K, and p38 MAPK in glioblastoma cell invasion. Conclusions: These findings indicate that X-rays and carbon ion irradiation effectively reduce proliferation and clonogenic survival without modifying the migration and invasion ability of glioblastoma cells in a collagen type I environment. Addition of targeted agents against members of the MAPK and PI3K signaling axis to conventional chemoradiation therapy seems potentially useful to optimize glioblastoma therapy.

  9. Growth in US health spending remained slow in 2010; health share of gross domestic product was unchanged from 2009.

    PubMed

    Martin, Anne B; Lassman, David; Washington, Benjamin; Catlin, Aaron

    2012-01-01

    Medical goods and services are generally viewed as necessities. Even so, the latest recession had a dramatic effect on their utilization. US health spending grew more slowly in 2009 and 2010-at rates of 3.8 percent and 3.9 percent, respectively-than in any other years during the fifty-one-year history of the National Health Expenditure Accounts. In 2010 extraordinarily slow growth in the use and intensity of services led to slower growth in spending for personal health care. The rates of growth in overall US gross domestic product (GDP) and in health spending began to converge in 2010. As a result, the health spending share of GDP stabilized at 17.9 percent.

  10. Visual Acuity Assessment in Persons with Dementia. Research Report

    ERIC Educational Resources Information Center

    Morse, Alan R.; Teresi, Jeanne; Rosenthal, Bruce; Holmes, Douglas; Yatzkan, Elaine S.

    2004-01-01

    Most studies of vision in persons with Alzheimer's disease either exclude those with advanced dementia or are unable to assess their vision adequately, and therefore, improperly report these persons' visual acuity status. In this study, visual acuity was assessed using the ETDRS Snellen-type acuity chart and Teller Acuity Cards. The Teller Acuity…

  11. Nonamblyopic eye visual acuity through Bangerter filters

    PubMed Central

    Rutstein, Robert P.; Foster, Nicole C.; Cotter, Susan A.; Kraker, Raymond T.; Lee, Dave H.; Melia, Michele; Quinn, Graham E.; Tamkins, Susanna M.; Wallace, David K.

    2011-01-01

    Purpose To describe the amount of visual acuity degradation induced by Bangerter filters in the better-seeing eye and to evaluate its stability over time in children with moderate amblyopia. Methods Visual acuity with and without a Bangerter filter was measured in the nonamblyopic eye of 186 children with moderate amblyopia who were then treated with either patching or with the Bangerter filters. A 0.2 filter was used for amblyopia of 20/80 and a 0.3 filter for amblyopia from 20/40 to 20/63. For the 89 children randomized to Bangerter filters, visual acuity was also measured in the nonamblyopic eye with and without the filters at both 6 weeks and 12 weeks after initiating treatment. Results Mean degradation in visual acuity of the nonamblyopic eye at baseline was 5.1 logMAR lines with the 0.2 filter and 4.8 logMAR lines with the 0.3 filter. The degradation with each filter did not always agree with the manufacturer’s specifications. Over time, the amount of degradation with the filters decreased. Conclusions The 0.2 and 0.3 Bangerter filters degrade nonamblyopic eye visual acuity sufficiently in amblyopic children. Because the amount of degradation decreases over time, it is recommended to periodically apply a new filter when using this type of amblyopia treatment. PMID:21419678

  12. Potential acuity meter for predicting visual acuity after Nd:YAG posterior capsulotomy

    SciTech Connect

    Smiddy, W.E.; Radulovic, D.; Yeo, J.H.; Stark, W.J.; Maumenee, A.E.

    1986-03-01

    We studied 30 patients with opacifications of the posterior capsule to determine if the potential acuity meter (PAM) could accurately predict final visual outcome after Nd:YAG discussion. The final visual acuity was within one line of the PAM prediction in 22 of 30 patients (73%), better by two or more lines in seven patients (23%), and worse in one patient (4%) by two lines. Although in thicker capsules the final acuity was occasionally better than the PAM prediction, the rates of false negative and false positive predictions were very low. Mild cystoid macular edema (3 patients), age-related macular degeneration (3 patients), intraocular lens status, and level of initial acuity did not diminish PAM accuracy. The PAM effectively predicts final visual acuity after YAG posterior capsulotomy, when used in a patient, unhurried manner.

  13. Visual Acuity of Children: United States.

    ERIC Educational Resources Information Center

    Health Services and Mental Health Administration (DHEW), Bethesda, MD.

    National estimates based on the findings from the Health Examination Survey in 1963 to 1965 of uncorrected monocular and binocular visual-acuity levels of children were studied. A nationwide sample of 7,417 children was selected to represent the approximately 24 million noninstitutionalized American children between ages 6 and 11 years. Testing…

  14. [The best corrected presenting distance visual acuity in forensic medicine].

    PubMed

    Liu, Rui-Jue

    2011-06-01

    At present the sight impairment evaluation in forensic medicine of China is based on the international classification of disease by WHO in 1973. The main measured indicator is "best corrected visual acuity". It is different from "presenting distance visual acuity" in some situations. In the new blindness and vision loss classification made by WHO in 2003, "presenting distance visual acuity" took the place of the "best corrected visual acuity". In the practice of forensic medicine, "presenting distance visual acuity" can not reflect the real visual acuity duo to the exaggeration or disguise of the wounded. We suggest to use "the best corrected presenting distance visual acuity" instead of "presenting distance visual acuity" in order to avoid the influences of the exaggeration or disguise of the wounded.

  15. 21 CFR 886.1150 - Visual acuity chart.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Visual acuity chart. 886.1150 Section 886.1150...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1150 Visual acuity chart. (a) Identification. A visual acuity chart is a device that is a chart, such as a Snellen chart with block letters...

  16. Variable acuity remote viewing system flight demonstration

    NASA Technical Reports Server (NTRS)

    Fisher, R. W.

    1983-01-01

    The Variable Acuity Remote Viewing System (VARVS), originally developed under contract to the Navy (ONR) as a laboratory brassboard, was modified for flight demonstration. The VARVS system was originally conceived as a technique which could circumvent the acuity/field of view/bandwidth tradeoffs that exists in remote viewing to provide a nearly eye limited display in both field of view (160 deg) and resolution (2 min arc) while utilizing conventional TV sensing, transmission, and display equipment. The modifications for flight demonstration consisted of modifying the sensor so it could be installed and flow in a Piper PA20 aircraft, equipped for remote control and modifying the display equipment so it could be integrated with the NASA Research RPB (RPRV) remote control cockpit.

  17. The neural correlates of learned motor acuity

    PubMed Central

    Yang, Juemin; Caffo, Brian; Mazzoni, Pietro; Krakauer, John W.

    2014-01-01

    We recently defined a component of motor skill learning as “motor acuity,” quantified as a shift in the speed-accuracy trade-off function for a task. These shifts are primarily driven by reductions in movement variability. To determine the neural correlates of improvement in motor acuity, we devised a motor task compatible with magnetic resonance brain imaging that required subjects to make finely controlled wrist movements under visual guidance. Subjects were imaged on day 1 and day 5 while they performed this task and were trained outside the scanner on intervening days 2, 3, and 4. The potential confound of performance changes between days 1 and 5 was avoided by constraining movement time to a fixed duration. After training, subjects showed a marked increase in success rate and a reduction in trial-by-trial variability for the trained task but not for an untrained control task, without changes in mean trajectory. The decrease in variability for the trained task was associated with increased activation in contralateral primary motor and premotor cortical areas and in ipsilateral cerebellum. A global nonlocalizing multivariate analysis confirmed that learning was associated with increased overall brain activation. We suggest that motor acuity is acquired through increases in the number of neurons recruited in contralateral motor cortical areas and in ipsilateral cerebellum, which could reflect increased signal-to-noise ratio in motor output and improved state estimation for feedback corrections, respectively. PMID:24848466

  18. Photometric Compliance of Tablet Screens and Retro-Illuminated Acuity Charts As Visual Acuity Measurement Devices

    PubMed Central

    Livingstone, I. A. T.; Tarbert, C. M.; Giardini, M. E.; Bastawrous, A.; Middleton, D.; Hamilton, R.

    2016-01-01

    Mobile technology is increasingly used to measure visual acuity. Standards for chart-based acuity tests specify photometric requirements for luminance, optotype contrast and luminance uniformity. Manufacturers provide some photometric data but little is known about tablet performance for visual acuity testing. This study photometrically characterised seven tablet computers (iPad, Apple inc.) and three ETDRS (Early Treatment Diabetic Retinopathy Study) visual acuity charts with room lights on and off, and compared findings with visual acuity measurement standards. Tablet screen luminance and contrast were measured using nine points across a black and white checkerboard test screen at five arbitrary brightness levels. ETDRS optotypes and adjacent white background luminance and contrast were measured. All seven tablets (room lights off) exceeded the most stringent requirement for mean luminance (≥ 120 cd/m2) providing the nominal brightness setting was above 50%. All exceeded contrast requirement (Weber ≥ 90%) regardless of brightness setting, and five were marginally below the required luminance uniformity threshold (Lmin/Lmax ≥ 80%). Re-assessing three tablets with room lights on made little difference to mean luminance or contrast, and improved luminance uniformity to exceed the threshold. The three EDTRS charts (room lights off) had adequate mean luminance (≥ 120 cd/m2) and Weber contrast (≥ 90%), but all three charts failed to meet the luminance uniformity standard (Lmin/Lmax ≥ 80%). Two charts were operating beyond manufacturer’s recommended lamp replacement schedule. With room lights on, chart mean luminance and Weber contrast increased, but two charts still had inadequate luminance uniformity. Tablet computers showed less inter-device variability, higher contrast, and better luminance uniformity than charts in both lights-on and lights-off environments, providing brightness setting was >50%. Overall, iPad tablets matched or marginally out

  19. Photometric Compliance of Tablet Screens and Retro-Illuminated Acuity Charts As Visual Acuity Measurement Devices.

    PubMed

    Livingstone, I A T; Tarbert, C M; Giardini, M E; Bastawrous, A; Middleton, D; Hamilton, R

    2016-01-01

    Mobile technology is increasingly used to measure visual acuity. Standards for chart-based acuity tests specify photometric requirements for luminance, optotype contrast and luminance uniformity. Manufacturers provide some photometric data but little is known about tablet performance for visual acuity testing. This study photometrically characterised seven tablet computers (iPad, Apple inc.) and three ETDRS (Early Treatment Diabetic Retinopathy Study) visual acuity charts with room lights on and off, and compared findings with visual acuity measurement standards. Tablet screen luminance and contrast were measured using nine points across a black and white checkerboard test screen at five arbitrary brightness levels. ETDRS optotypes and adjacent white background luminance and contrast were measured. All seven tablets (room lights off) exceeded the most stringent requirement for mean luminance (≥ 120 cd/m2) providing the nominal brightness setting was above 50%. All exceeded contrast requirement (Weber ≥ 90%) regardless of brightness setting, and five were marginally below the required luminance uniformity threshold (Lmin/Lmax ≥ 80%). Re-assessing three tablets with room lights on made little difference to mean luminance or contrast, and improved luminance uniformity to exceed the threshold. The three EDTRS charts (room lights off) had adequate mean luminance (≥ 120 cd/m2) and Weber contrast (≥ 90%), but all three charts failed to meet the luminance uniformity standard (Lmin/Lmax ≥ 80%). Two charts were operating beyond manufacturer's recommended lamp replacement schedule. With room lights on, chart mean luminance and Weber contrast increased, but two charts still had inadequate luminance uniformity. Tablet computers showed less inter-device variability, higher contrast, and better luminance uniformity than charts in both lights-on and lights-off environments, providing brightness setting was >50%. Overall, iPad tablets matched or marginally out

  20. Response Classification Images in Vernier Acuity

    NASA Technical Reports Server (NTRS)

    Ahumada, Albert J., Jr.; Beard, B. L.; Ellis, Stephen R. (Technical Monitor)

    1997-01-01

    Orientation selective and local sign mechanisms have been proposed as the basis for vernier acuity judgments. Linear image features contributing to discrimination can be determined for a two choice task by adding external noise to the images and then averaging the noises separately for the four types of stimulus/response trials. This method is applied to a vernier acuity task with different spatial separations to compare the predictions of the two theories. Three well-practiced observers were presented around 5000 trials of a vernier stimulus consisting of two dark horizontal lines (5 min by 0.3 min) within additive low-contrast white noise. Two spatial separations were tested, abutting and a 10 min horizontal separation. The task was to determine whether the target lines were aligned or vertically offset. The noises were averaged separately for the four stimulus/response trial types (e.g., stimulus = offset, response = aligned). The sum of the two 'not aligned' images was then subtracted from the sum of the 'aligned' images to obtain an overall image. Spatially smoothed images were quantized according to expected variability in the smoothed images to allow estimation of the statistical significance of image features. The response images from the 10 min separation condition are consistent with the local sign theory, having the appearance of two linear operators measuring vertical position with opposite sign. The images from the abutting stimulus have the same appearance with the two operators closer together. The image predicted by an oriented filter model is similar, but has its greatest weight in the abutting region, while the response images fall to nonsignificance there. The response correlation image method, previously demonstrated for letter discrimination, clarifies the features used in vernier acuity.

  1. Predicting visual acuity from the structure of visual cortex

    PubMed Central

    Srinivasan, Shyam; Carlo, C. Nikoosh; Stevens, Charles F.

    2015-01-01

    Three decades ago, Rockel et al. proposed that neuronal surface densities (number of neurons under a square millimeter of surface) of primary visual cortices (V1s) in primates is 2.5 times higher than the neuronal density of V1s in nonprimates or many other cortical regions in primates and nonprimates. This claim has remained controversial and much debated. We replicated the study of Rockel et al. with attention to modern stereological precepts and show that indeed primate V1 is 2.5 times denser (number of neurons per square millimeter) than many other cortical regions and nonprimate V1s; we also show that V2 is 1.7 times as dense. As primate V1s are denser, they have more neurons and thus more pinwheels than similar-sized nonprimate V1s, which explains why primates have better visual acuity. PMID:26056277

  2. Visual acuity estimation from simulated images

    NASA Astrophysics Data System (ADS)

    Duncan, William J.

    Simulated images can provide insight into the performance of optical systems, especially those with complicated features. Many modern solutions for presbyopia and cataracts feature sophisticated power geometries or diffractive elements. Some intraocular lenses (IOLs) arrive at multifocality through the use of a diffractive surface and multifocal contact lenses have a radially varying power profile. These type of elements induce simultaneous vision as well as affecting vision much differently than a monofocal ophthalmic appliance. With myriad multifocal ophthalmics available on the market it is difficult to compare or assess performance in ways that effect wearers of such appliances. Here we present software and algorithmic metrics that can be used to qualitatively and quantitatively compare ophthalmic element performance, with specific examples of bifocal intraocular lenses (IOLs) and multifocal contact lenses. We anticipate this study, methods, and results to serve as a starting point for more complex models of vision and visual acuity in a setting where modeling is advantageous. Generating simulated images of real- scene scenarios is useful for patients in assessing vision quality with a certain appliance. Visual acuity estimation can serve as an important tool for manufacturing and design of ophthalmic appliances.

  3. Stream segregation with high spatial acuity

    PubMed Central

    Middlebrooks, John C.; Onsan, Zekiye A.

    2012-01-01

    Spatial hearing is widely regarded as helpful in recognizing a sound amid other competing sounds. It is a matter of debate, however, whether spatial cues contribute to “stream segregation,” which refers to the specific task of assigning multiple interleaved sequences of sounds to their respective sources. The present study employed “rhythmic masking release” as a measure of the spatial acuity of stream segregation. Listeners discriminated between rhythms of noise-burst sequences presented from free-field targets in the presence of interleaved maskers that varied in location. For broadband sounds in the horizontal plane, target-masker separations of ≥8° permitted rhythm discrimination with d′ ≥ 1; in some cases, such thresholds approached listeners’ minimum audible angles. Thresholds were the same for low-frequency sounds but were substantially wider for high-frequency sounds, suggesting that interaural delays provided higher spatial acuity in this task than did interaural level differences. In the vertical midline, performance varied dramatically as a function of noise-burst duration with median thresholds ranging from >30° for 10-ms bursts to 7.1° for 40-ms bursts. A marked dissociation between minimum audible angles and masking release thresholds across the various pass-band and burst-duration conditions suggests that location discrimination and spatial stream segregation are mediated by distinct auditory mechanisms. PMID:23231120

  4. Visual acuity in the cathemeral strepsirrhine Eulemur macaco flavifrons.

    PubMed

    Veilleux, Carrie C; Kirk, E Christopher

    2009-04-01

    Studies of visual acuity in primates have shown that diurnal haplorhines have higher acuity (30-75 cycles per degree (c/deg)) than most other mammals. However, relatively little is known about visual acuity in non-haplorhine primates, and published estimates are only available for four strepsirrhine genera (Microcebus, Otolemur, Galago, and Lemur). We present here the first measurements of visual acuity in a cathemeral strepsirrhine species, the blue-eyed black lemur (Eulemur macaco flavifrons). Acuity in two subjects, a 3-year-old male and a 16-year-old female, was assessed behaviorally using a two-alternative forced choice discrimination task. Visual stimuli consisted of high contrast square wave gratings of seven spatial frequencies. Acuity threshold was determined using a 70% correct response criterion. Results indicate a maximum visual acuity of 5.1 c/deg for the female (1718 trials) and 3.8 c/deg for the male (846 trials). These values for E. macaco are slightly lower than those reported for diurnal Lemur catta, and are generally comparable to those reported for nocturnal Microcebus murinus and Otolemur crassicaudatus. To examine ecological sources of variation in primate visual acuity, we also calculated maximum theoretical acuity for Cheirogaleus medius (2.8 c/deg) and Tarsius syrichta (8.9 c/deg) using published data on retinal ganglion cell density and eye morphology. These data suggest that visual acuity in primates may be influenced by activity pattern, diet, and phylogenetic history. In particular, the relatively high acuity of T. syrichta and Galago senegalensis suggests that visual predation may be an important selective factor favoring high visual acuity in primates.

  5. New Evidence on Causal Relationship between Approximate Number System (ANS) Acuity and Arithmetic Ability in Elementary-School Students: A Longitudinal Cross-Lagged Analysis

    PubMed Central

    He, Yunfeng; Zhou, Xinlin; Shi, Dexin; Song, Hairong; Zhang, Hui; Shi, Jiannong

    2016-01-01

    Approximate number system (ANS) acuity and mathematical ability have been found to be closely associated in recent studies. However, whether and how these two measures are causally related still remain less addressed. There are two hypotheses about the possible causal relationship: ANS acuity influences mathematical performances, or access to math education sharpens ANS acuity. Evidences in support of both hypotheses have been reported, but these two hypotheses have never been tested simultaneously. Therefore, questions still remain whether only one-direction or reciprocal causal relationships existed in the association. In this work, we provided a new evidence on the causal relationship between ANS acuity and arithmetic ability. ANS acuity and mathematical ability of elementary-school students were measured sequentially at three time points within one year, and all possible causal directions were evaluated simultaneously using cross-lagged regression analysis. The results show that ANS acuity influences later arithmetic ability while the reverse causal direction was not supported. Our finding adds a strong evidence to the causal association between ANS acuity and mathematical ability, and also has important implications for educational intervention designed to train ANS acuity and thereby promote mathematical ability. PMID:27462291

  6. Cooperative neural processes involved in stereoscopic acuity.

    PubMed

    Westheimer, G

    1979-08-01

    Results of psychophysical experiments are reported showing that synchrony, appropriate relative placement, and absence of standing disparity are important conditions to be met by members of a target configuration if they are to participate in the cooperative neural processes leading to the best disparity discrimination. Consecutive binocular presentation of the members of a stereo target decreases stereoacuity by a factor of about 10, and a step disparity displacement of a single line target needs to be larger still to be detected as a depth stimulus. A standing disaprity of even one minute of arc at least doubles the disaprity disxrimination threshold. It is postulated that a differencing mechanism operates on the depth signal of individual features; the temporal and spatial optima of target presentation for stereoscopic acuity outline the character of the concerned operations.

  7. Bayesian model of Snellen visual acuity.

    PubMed

    Nestares, Oscar; Navarro, Rafael; Antona, Beatriz

    2003-07-01

    A Bayesian model of Snellen visual acuity (VA) has been developed that, as far as we know, is the first one that includes the three main stages of VA: (1) optical degradations, (2) neural image representation and contrast thresholding, and (3) character recognition. The retinal image of a Snellen test chart is obtained from experimental wave-aberration data. Then a subband image decomposition with a set of visual channels tuned to different spatial frequencies and orientations is applied to the retinal image, as in standard computational models of early cortical image representation. A neural threshold is applied to the contrast responses to include the effect of the neural contrast sensitivity. The resulting image representation is the base of a Bayesian pattern-recognition method robust to the presence of optical aberrations. The model is applied to images containing sets of letter optotypes at different scales, and the number of correct answers is obtained at each scale; the final output is the decimal Snellen VA. The model has no free parameters to adjust. The main input data are the eye's optical aberrations, and standard values are used for all other parameters, including the Stiles-Crawford effect, visual channels, and neural contrast threshold, when no subject specific values are available. When aberrations are large, Snellen VA involving pattern recognition differs from grating acuity, which is based on a simpler detection (or orientation-discrimination) task and hence is basically unaffected by phase distortions introduced by the optical transfer function. A preliminary test of the model in one subject produced close agreement between actual measurements and predicted VA values. Two examples are also included: (1) application of the method to the prediction of the VAin refractive-surgery patients and (2) simulation of the VA attainable by correcting ocular aberrations.

  8. Astronaut Frank Borman performing visual acuity tests in space

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronaut Frank Borman is seen performing visual acuity tests in space. Views include Borman looking at the camera as light shines through the capsule window (63712); Borman is using the visual acuity device and a portable mouth thermometer during his experiment (63713).

  9. Brief Report: Visual Acuity in Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Albrecht, Matthew A.; Stuart, Geoffrey W.; Falkmer, Marita; Ordqvist, Anna; Leung, Denise; Foster, Jonathan K.; Falkmer, Torbjorn

    2014-01-01

    Recently, there has been heightened interest in suggestions of enhanced visual acuity in autism spectrum disorders (ASD) which was sparked by evidence that was later accepted to be methodologically flawed. However, a recent study that claimed children with ASD have enhanced visual acuity (Brosnan et al. in "J Autism Dev Disord"…

  10. 49 CFR 242.117 - Vision and hearing acuity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Vision and hearing acuity. 242.117 Section 242.117... Requirements § 242.117 Vision and hearing acuity. (a) Each railroad shall adopt and comply with a program which... person's vision and hearing shall meet or exceed the standards prescribed in this section and Appendix...

  11. 49 CFR 242.117 - Vision and hearing acuity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Vision and hearing acuity. 242.117 Section 242.117... Requirements § 242.117 Vision and hearing acuity. (a) Each railroad shall adopt and comply with a program which... person's vision and hearing shall meet or exceed the standards prescribed in this section and Appendix...

  12. 49 CFR 242.117 - Vision and hearing acuity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Vision and hearing acuity. 242.117 Section 242.117... Requirements § 242.117 Vision and hearing acuity. (a) Each railroad shall adopt and comply with a program which... person's vision and hearing shall meet or exceed the standards prescribed in this section and Appendix...

  13. On using Vernier acuity to assess magnocellular sensitivity.

    PubMed

    Skottun, Bernt C; Skoyles, John R

    2010-03-01

    A recent study [Keri, S., & Benedek, G. (2009). Visual pathway deficit in female fragile x premutation carriers: A potential endophenotype. Brain and Cognition, 69, 291-295] has found Vernier acuity deficiencies together with contrast sensitivity defects consistent with a magnocellular deficit in female fragile x premutation carriers. This may appear to support the notion that Vernier acuity may serve as a test of magnocellular sensitivity. However, Vernier acuity deficiencies have been reported in other conditions (e.g., schizophrenia, amblyopia and cortical visual impairment) where there is little evidence for magnocellular deficits. The observation that Vernier acuity deficiencies can occur without magnocellular deficits indicates that Vernier acuity is not a reliable test of magnocellular sensitivity.

  14. Visual acuity in the short-tailed opossum (Monodelphis domestica).

    PubMed

    Dooley, J C; Nguyen, H M; Seelke, A M H; Krubitzer, L

    2012-10-25

    Monodelphis domestica (short-tailed opossum) is an emerging animal model for studies of neural development due to the extremely immature state of the nervous system at birth and its subsequent rapid growth to adulthood. Yet little is known about its normal sensory discrimination abilities. In the present investigation, visual acuity was determined in this species using the optokinetic test (OPT), which relies on involuntary head tracking of a moving stimulus and can be easily elicited using a rotating visual stimulus of varying spatial frequencies. Using this methodology, we determined that the acuity of Monodelphis is 0.58 cycles per degree (cpd), which is similar to the acuity of rats using the same methodology, and higher than in mice. However, acuity in the short-tailed opossum is lower than in other marsupials. This is in part due to the methodology used to determine acuity, but may also be due to differences in diel patterns, lifestyle and phylogeny. We demonstrate that for the short-tailed opossum, the OPT is a rapid and reliable method of determining a baseline acuity and can be used to study enhanced acuities due to cortical plasticity.

  15. Visual acuity in the short-tailed opossum (Monodelphis domestica)

    PubMed Central

    Dooley, James C.; Nguyen, Hoang; Seelke, Adele M. H.; Krubitzer, Leah

    2013-01-01

    Monodelphis domestica (short-tailed opossum) is an emerging animal model for studies of neural development due to the extremely immature state of the nervous system at birth and its subsequent rapid growth to adulthood. Yet little is known about its normal sensory discrimination abilities. In the present investigation, visual acuity was determined in this species using the optokinetic test (OPT), which relies on involuntary head tracking of a moving stimulus and can be easily elicited using a rotating visual stimulus of varying spatial frequencies. Using this methodology, we determined that the acuity of Monodelphis is 0.58 cycles per degree (cpd), which is similar to the acuity of rats using the same methodology, and higher than in mice. However, acuity in the short-tailed opossum is lower than in other marsupials. This is in part due to the methodology used to determine acuity, but may also be due to differences in diel patterns, lifestyle and phylogeny. We demonstrate that for the short-tailed opossum, the OPT is a rapid and reliable method of determining a baseline acuity and can be used to study enhanced acuities due to cortical plasticity. PMID:22871523

  16. RETENTION OF HIGH TACTILE ACUITY THROUGHOUT THE LIFESPAN IN BLINDNESS

    PubMed Central

    Legge, Gordon E.; Madison, Cindee; Vaughn, Brenna N.; Cheong, Allen M.Y.; Miller, Joseph C.

    2009-01-01

    Previous studies of tactile acuity on the fingertip using passive touch have demonstrated an age-related decline in spatial resolution for both sighted and blind subjects. We have re-examined this age dependence with two newly designed tactile-acuity charts requiring active exploration of the test symbols. One chart used dot patterns similar to Braille and the other used embossed Landolt rings. Groups of blind Braille readers and sighted subjects, ranging in age from 12 to 85 years, were tested in two experiments. We replicated previous findings for sighted subjects by showing an age related decrease in tactile acuity by nearly 1% per year. Surprisingly, the blind subjects retained high acuity into old age showing no age-related decline. For the blind subjects, tactile acuity did not correlate with braille reading speed, the amount of daily reading, or the age at which braille was learned. We conclude that when measured with active touch, blind subjects retain high tactile acuity into old age, unlike their aging sighted peers. We propose that blind people's use of active touch in daily activities, not specifically Braille reading, results in preservation of tactile acuity across the lifespan. PMID:19064491

  17. Visual acuity, color vision, and visual search performance at sea.

    PubMed

    Donderi, D C

    1994-03-01

    Visual acuity and color vision were tested during a search and rescue exercise at sea. Fifty-seven watchkeepers searched for orange and yellow life rafts during daylight and for lighted and unlighted life rafts at night with night vision goggles. There were 588 individual watches of one hour each. Measures of wind, waves, and weather were used as covariates. Daytime percentage detection was positively correlated with low-contrast visual acuity and negatively correlated with error scores on Dvorine pseudoisochromatic plates and the Farnsworth color test. Performance was better during the first half-hour of the watch. Efficiency calculations show that color vision selective screening at one standard deviation above the mean would increase daylight search performance by 10% and that one standard deviation visual acuity selection screening would increase performance by 12%. There was no relationship between either acuity or color vision and life raft detection using night vision goggles.

  18. The development of an obstetric triage acuity tool.

    PubMed

    Paisley, Kathleen S; Wallace, Ruth; DuRant, Patricia G

    2011-01-01

    The purpose of this article is to describe the journey a multicampus hospital system took to improve the obstetric triage process. A review of literature revealed no current comprehensive obstetric acuity tool, and thus our team developed a tool with a patient flow process, revised and updated triage nurse competencies, and then educated the nurses about the new tool and process. Data were collected to assess the functionality of the new process in assigning acuity upon patient arrival, conveying appropriate acuities based on patient complaints, and initiating the medical screening examination, all within prescribed time intervals. Initially data indicated that processes were still not optimal, and re-education was provided for all triage nurses. This improved all data points. The result of this QI project is that our patients are now seen based on their acuity within designated time frames.

  19. Measuring Observers’ Visual Acuity Through Night Vision Goggles

    DTIC Science & Technology

    1998-01-01

    a two-alternative, forced-choice ( 2AFC ) method to determine visual acuity through NVGs as a function of night-time ambient illumination levels. A...computer executed the 2AFC (gap seen up or down), Step Program adapted from Simpson (1989). Based on the observerÕs last response, the program selected...threshold levels, NVG drift, good guessing in the 2AFC method, fatigue, eye strain, sinus headaches and so on. METHOD Psychometric Function of Acuity

  20. Association between individual differences in non-symbolic number acuity and math performance: a meta-analysis.

    PubMed

    Chen, Qixuan; Li, Jingguang

    2014-05-01

    Many recent studies have examined the association between number acuity, which is the ability to rapidly and non-symbolically estimate the quantity of items appearing in a scene, and symbolic math performance. However, various contradictory results have been reported. To comprehensively evaluate the association between number acuity and symbolic math performance, we conduct a meta-analysis to synthesize the results observed in previous studies. First, a meta-analysis of cross-sectional studies (36 samples, N = 4705) revealed a significant positive correlation between these skills (r = 0.20, 95% CI = [0.14, 0.26]); the association remained after considering other potential moderators (e.g., whether general cognitive abilities were controlled). Moreover, a meta-analysis of longitudinal studies revealed 1) that number acuity may prospectively predict later math performance (r = 0.24, 95% CI = [0.11, 0.37]; 6 samples) and 2) that number acuity is retrospectively correlated to early math performance as well (r = 0.17, 95% CI = [0.07, 0.26]; 5 samples). In summary, these pieces of evidence demonstrate a moderate but statistically significant association between number acuity and math performance. Based on the estimated effect sizes, power analyses were conducted, which suggested that many previous studies were underpowered due to small sample sizes. This may account for the disparity between findings in the literature, at least in part. Finally, the theoretical and practical implications of our meta-analytic findings are presented, and future research questions are discussed.

  1. Changes in the clinical measurement of visual acuity

    NASA Astrophysics Data System (ADS)

    Bailey, I. L.; Jackson, A. J.

    2016-11-01

    In 1862, Hermann Snellen introduced his letter chart for the clinical measurement of visual acuity. His chart presented letters,or optotypes, arranged in a progressively diminishing size sequence, and the visual acuity was determined by the smallest letters that could read at a specified distance. Numerous modifications of the design of the optotypes, the progression of size and the chart layout were suggested, and in 1976, Bailey and Lovie published a set of design principles that made the visual task the same at all size levels, so that size become the only significant variable. This required the same number of letters at each size level, fixed spacing ratios and a logarithmic progression of size. This facilitates more precise quantification of visual acuity by giving credit for every letter read correctly, and this gives clinicians tighter confidence limits for determining changes or differences in visual acuity. However, optotype choices, and associated spacing arrangements can have significant effects on visual acuity scores as can viewing conditions and testing protocols. Computer based visual acuity tests are becoming more commonplace, there will be more variety in test charts and procedures which will create some problems for making comparisons between tests.

  2. Visual acuity in mammals: effects of eye size and ecology.

    PubMed

    Veilleux, Carrie C; Kirk, E Christopher

    2014-01-01

    Previous comparative research has attributed interspecific variation in eye size among mammals to selection related to visual acuity. Mammalian species have also been hypothesized to differ in visual acuity partly as a result of differences in ecology. While a number of prior studies have explored ecological and phylogenetic effects on eye shape, a broad comparative analysis of the relationships between visual acuity, eye size and ecology in mammals is currently lacking. Here we use phylogenetic comparative methods to explore these relationships in a taxonomically and ecologically diverse sample of 91 mammal species. These data confirm that axial eye length and visual acuity are significantly positively correlated in mammals. This relationship conforms to expectations based on theoretical optics and prior analyses of smaller comparative samples. Our data also demonstrate that higher visual acuity in mammals is associated with: (1) diurnality and (2) predatory habits once the effects of eye size and phylogeny have been statistically controlled. These results suggest that interspecific variation in mammalian visual acuity is the result of a complex interplay between phylogenetic history, visual anatomy and ecology.

  3. [PALEOPATHOLOGY OF HUMAN REMAINS].

    PubMed

    Minozzi, Simona; Fornaciari, Gino

    2015-01-01

    Many diseases induce alterations in the human skeleton, leaving traces of their presence in ancient remains. Paleopathological examination of human remains not only allows the study of the history and evolution of the disease, but also the reconstruction of health conditions in the past populations. This paper describes the most interesting diseases observed in skeletal samples from the Roman Imperial Age necropoles found in urban and suburban areas of Rome during archaeological excavations in the last decades. The diseases observed were grouped into the following categories: articular diseases, traumas, infections, metabolic or nutritional diseases, congenital diseases and tumours, and some examples are reported for each group. Although extensive epidemiological investigation in ancient skeletal records is impossible, the palaeopathological study allowed to highlight the spread of numerous illnesses, many of which can be related to the life and health conditions of the Roman population.

  4. Propellant-remaining modeling

    NASA Technical Reports Server (NTRS)

    Torgovitsky, S.

    1991-01-01

    A successful satellite mission is predicted upon the proper maintenance of the spacecraft's orbit and attitude. One requirement for planning and predicting the orbit and attitude is the accurate estimation of the propellant remaining onboard the spacecraft. Focuss is on the three methods that were developed for calculating the propellant budget: the errors associated with each method and the uncertainties in the variables required to determine the propellant remaining that contribute to these errors. Based on these findings, a strategy is developed for improved propellant-remaining estimation. The first method is based on Boyle's law, which related the values of pressure, volume, and temperature (PVT) of an ideal gas. The PVT method is used for the monopropellant and the bipropellant engines. The second method is based on the engine performance tests, which provide data that relate thrust and specific impulse associated with a propellant tank to that tank's pressure. Two curves representing thrust and specific impulse as functions of pressure are then generated using a polynomial fit on the engine performance data. The third method involves a computer simulation of the propellant system. The propellant flow is modeled by creating a conceptual model of the propulsion system configuration, taking into account such factors as the propellant and pressurant tank characteristics, thruster functionality, and piping layout. Finally, a thrust calibration technique is presented that uses differential correction with the computer simulation method of propellant-remaining modeling. Thrust calibration provides a better assessment of thruster performance and therefore enables a more accurate estimation of propellant consumed during a given maneuver.

  5. Improving Visual Acuity of Myopes through Operant Training: The Evaluation of Psychological and Physiological Mechanisms Facilitating Acuity Enhancement

    DTIC Science & Technology

    1988-12-01

    at far distances. High degrees of myopia are often accompanied by damage to the eye’s fundus and, when extreme, cannot be fully compensated by...refractively measured myopia . He attributed the improvement to experience in correct interpretation of a blurred visual image . Gibson (1953) proposed that...acuity is an alterable process. If acuity can be enhanced, it could benefit some of the nearly one billion individuals who have myopia or

  6. The Jasper Ridge elevated CO{sub 2} experiment: Root acid phosphatase activity in Bromus hordeaceus and Avena barbata remains unchanged under elevated [CO{sub 2}

    SciTech Connect

    Cardon, Z.G.; Jackson, R.

    1995-06-01

    Root acid phosphatase activity increases phosphate available to plants by cleaving phosphate esters in soil organic matter. Because of increased plant growth potential under elevated [CO{sub 2}], we hypothesized that high [CO{sub 2}]-grown plants might exhibit higher phosphatase activity than low [CO{sub 2}]-grown plants. We assayed phosphatase activity in two species grown on two substrates (Bromus on serpentine soil and Bromus and Avena on sandstone soil) under high and low [CO{sub 2}] and under several nutrient treatments. Phosphatase activity was expressed per gram fresh weight of roots. Phosphatase activity of Bromus roots (on sandstone) was first assayed in treatments where only P and K, or only N, were added to soil. Bromus roots in this case showed strong induction of phosphatase activity when N only had been added to soil, indicating that Bromus regulated its phosphatase activity in response to phosphate availability. Both Bromus and Avena growing in sandstone, and Bromus growing in serpentine, showed enhanced phosphatase activity at high nutrient (N, P, and K) levels over that at low nutrient levels, but no differences between phosphatase activity were apparent between [CO{sub 2}] treatments. The increased phosphatase activity at high N, P, and K may indicate enhanced {open_quotes}growth demand{close_quotes} (reflected in higher biomass) in both Avena and Bromus. In contrast, though Bromus {open_quotes}growth demand{close_quotes} (biomass) increased under high [CO{sub 2}] on sandstone, phosphatase activity did not increase.

  7. Cell-specific CO2 fixation rates of two distinct groups of plastidic protists in the Atlantic Ocean remain unchanged after nutrient addition.

    PubMed

    Grob, Carolina; Jardillier, Ludwig; Hartmann, Manuela; Ostrowski, Martin; Zubkov, Mikhail V; Scanlan, David J

    2015-04-01

    To assess the role of open-ocean ecosystems in global CO2 fixation, we investigated how picophytoplankton, which dominate primary production, responded to episodic increases in nutrient availability. Previous experiments have shown nitrogen alone, or in combination with phosphorus or iron, to be the proximate limiting nutrient(s) for total phytoplankton grown over several days. Much less is known about how nutrient upshift affects picophytoplankton CO2 fixation over the duration of the light period. To address this issue, we performed a series of small volume (8-60 ml) - short term (10-11 h) nutrient addition experiments in different regions of the Atlantic Ocean using NH4 Cl, FeCl3 , K medium, dust and nutrient-rich water from 300 m depth. We found no significant nutrient stimulation of group-specific CO2 fixation rates of two taxonomically and size-distinct groups of plastidic protists. The above was true regardless of the region sampled or nutrient added, suggesting that this is a generic phenomenon. Our findings show that at least in the short term (i.e. daylight period), nutrient availability does not limit CO2 fixation by the smallest plastidic protists, while their taxonomic composition does not determine their response to nutrient addition.

  8. [What remains of arthrography?].

    PubMed

    Morvan, G

    1994-06-15

    At the time of RMI, arthrography appears sometimes old-fashioned. However this exam, which knows a second youth in relation with the supply of CT-scan (arthro-CT) remains the gold-standard in the exploration of many pathologic situations: intra-articular foreign bodies, tears of glenoid or acetabular labrum, precise assessment of chondral or ligamentous lesions (especially of the ankle), sub-scapularis tendon tears, adhesive capsulitis, complications of prosthesis, appreciation of intra-articular position of the needle's tip before injection of a therapeutic drug. Arthrography, completed or not by CT-slices gives, in this indications, excellent spatial resolution images, easy to perform, to read, to understand and to transmit at the clinicians, with a reasonable cost and a minor risk. RMI is a more and more used alternative, especially for the study of meniscus and ligaments of the knee, and rotator's cuff of the shoulder. It's sure that, with the increase of the RMI image's quality, other common indications will slip towards this technique, but nevertheless at this time (and it seams to me, for a long time) arthrography and arthro-CT will remain an excellent diagnostic tool with a very competitive advantages/inconvenience ratio.

  9. Preschool acuity of the approximate number system correlates with school math ability.

    PubMed

    Libertus, Melissa E; Feigenson, Lisa; Halberda, Justin

    2011-11-01

    Previous research shows a correlation between individual differences in people's school math abilities and the accuracy with which they rapidly and nonverbally approximate how many items are in a scene. This finding is surprising because the Approximate Number System (ANS) underlying numerical estimation is shared with infants and with non-human animals who never acquire formal mathematics. However, it remains unclear whether the link between individual differences in math ability and the ANS depends on formal mathematics instruction. Earlier studies demonstrating this link tested participants only after they had received many years of mathematics education, or assessed participants' ANS acuity using tasks that required additional symbolic or arithmetic processing similar to that required in standardized math tests. To ask whether the ANS and math ability are linked early in life, we measured the ANS acuity of 200 3- to 5-year-old children using a task that did not also require symbol use or arithmetic calculation. We also measured children's math ability and vocabulary size prior to the onset of formal math instruction. We found that children's ANS acuity correlated with their math ability, even when age and verbal skills were controlled for. These findings provide evidence for a relationship between the primitive sense of number and math ability starting early in life.

  10. Tactile spatial acuity varies with site and axis in the human upper limb.

    PubMed

    Cody, Frederick W J; Garside, Rebecca A D; Lloyd, Donna; Poliakoff, Ellen

    2008-03-12

    Historically, beginning with Weber's [E.H. Weber, On the sensitivity of the tactile senses, in: H.E. Ross, D.J. Murray (Eds. and Trans.), E.H. Weber on the Tactile Senses, Erlbaum (UK) Taylor & Francis, Hove, 1996 (Original work published in 1834), pp. 21-136] classical studies, regional variations in the accuracy of localisation of tactile stimuli applied to a limb have been recognised. However, important questions remain concerning both the map of localisation resolution and its neuroscientific basis since methodological confounds have militated against an unambiguous, unified interpretation of the diverse findings. To test the hypotheses that localisation precision on the upper limb varies with site (hand, wrist, forearm) and limb axis (transverse, longitudinal), regional differences in locognosic acuity were quantified in psychophysical experiments. Participants identified the perceived direction (e.g. medial or lateral) relative to a central reference locus of brief tactile test stimuli applied to a cruciform array of loci. Acuity was greater in the transverse than longitudinal axis. This effect probably arises from the asymmetry of receptive fields of upper limb first-order sensory units and their higher-order projection neurons. Additionally, acuity was greater on the dorsal surface at the wrist than either the hand or forearm sites, in the longitudinal axis, supporting an enhancement of resolution at joints (anchor points). This effect may contribute to improved proprioceptive guidance of active wrist movements.

  11. Dynamic visual acuity using "far" and "near" targets

    NASA Technical Reports Server (NTRS)

    Peters, Brian T.; Bloomberg, Jacob J.

    2005-01-01

    CONCLUSIONS: DVA may be useful for assessing the functional consequences of an impaired gaze stabilization mechanism or for testing the effectiveness of a rehabilitation paradigm. Because target distance influences the relative contributions of canal and otolith inputs, the ability to measure DVA at near and far viewing distances may also lead to tests that will independently assess canal and otolith function. OBJECTIVE: To present and test a methodology that uses dynamic visual acuity (DVA) to assess the efficacy of compensatory gaze mechanisms during a functionally relevant activity that differentially measures canal and otolith function. MATERIAL AND METHODS: The effect of treadmill walking at a velocity of 1.79 m/s on subjects' visual acuity was assessed at each of two viewing distances. A custom-written threshold determination program was used to display Landolt C optotypes on a laptop computer screen during a "far" (4 m) target condition and on a micro-display for a "near" (50 cm) target condition. The walking acuity scores for each target distance were normalized by subtracting a corresponding acuity measure obtained while standing still on the treadmill belt. RESULTS: As predicted by subjective reports of relative target motion, the decrease in visual acuity was significantly greater (p < 0.00001) for the near compared to the far condition.

  12. How well do you see what you hear? The acuity of visual-to-auditory sensory substitution

    PubMed Central

    Haigh, Alastair; Brown, David J.; Meijer, Peter; Proulx, Michael J.

    2013-01-01

    Sensory substitution devices (SSDs) aim to compensate for the loss of a sensory modality, typically vision, by converting information from the lost modality into stimuli in a remaining modality. “The vOICe” is a visual-to-auditory SSD which encodes images taken by a camera worn by the user into “soundscapes” such that experienced users can extract information about their surroundings. Here we investigated how much detail was resolvable during the early induction stages by testing the acuity of blindfolded sighted, naïve vOICe users. Initial performance was well above chance. Participants who took the test twice as a form of minimal training showed a marked improvement on the second test. Acuity was slightly but not significantly impaired when participants wore a camera and judged letter orientations “live”. A positive correlation was found between participants' musical training and their acuity. The relationship between auditory expertise via musical training and the lack of a relationship with visual imagery, suggests that early use of a SSD draws primarily on the mechanisms of the sensory modality being used rather than the one being substituted. If vision is lost, audition represents the sensory channel of highest bandwidth of those remaining. The level of acuity found here, and the fact it was achieved with very little experience in sensory substitution by naïve users is promising. PMID:23785345

  13. The Effect of Zeaxanthin on the Visual Acuity of Zebrafish.

    PubMed

    Saidi, Eric A; Davey, Pinakin Gunvant; Cameron, D Joshua

    2015-01-01

    Oral supplementation of carotenoids such as zeaxanthin or lutein which naturally occur in human retina have been shown to improve vision and prevent progression of damage to advanced AMD in some studies. The zebrafish eye shares many physiological similarities with the human eye and is increasingly being used as model for vision research. We hypothesized that injection of zeaxanthin into the zebrafish eye would improve the visual acuity of the zebrafish over time. Visual acuity, calculated in cycles per degree, was measured in adult zebrafish to establish a consistent baseline using the optokinetic response. Zeaxanthin dissolved into phosphate buffered saline (PBS) or PBS only was injected into the anterior chamber of the right and left eyes of the Zebrafish. Visual acuities were measured at 1 week and 3, 8 and 12 weeks post-injection to compare to baseline values. Repeated measures ANOVA was used to compare visual acuities between fish injected with PBS and zeaxanthin. A significant improvement in visual acuity, 14% better than before the injection (baseline levels), was observed one week after injection with zeaxanthin (p = 0.04). This improvement peaked at more than 30% for some fish a few weeks after the injection and improvement in vision persisted at 3 weeks after injection (p = 0.006). The enhanced visual function was not significantly better than baseline at 8 weeks (p = 0.19) and returned to baseline levels 12 weeks after the initial injection (p = 0.50). Zeaxanthin can improve visual acuity in zebrafish eyes. Further studies are required to develop a better understanding of the role zeaxanthin and other carotenoids play during normal visual function.

  14. Fresnel prisms and their effects on visual acuity and binocularity.

    PubMed Central

    Véronneau-Troutman, S

    1978-01-01

    1. The visual acuity with the Fresnel membrane prism is significantly less than that with the conventional prism of the same power for all prism powers from 12 delta through 30 delata at distance and from 15 delta through 30 delta at near. 2. The difference in the visual acuity between base up and base down, and between base in and base out, is not significantly different for either the Fresnel membrane prism or for the conventional prism. 3. For both Fresnel membrane prism and the conventional prism, the visual acuity when looking straight ahead. 4. Using Fresnel membrane prisms of the same power from different lots, the visual acuity varied significantly. The 30 delta prism caused the widest range in visual acuity. 5. When normal subjects are fitted with the higher powers of the Fresnel membrane prism, fusion and stereopsis are disrupted to such an extent that the use of this device to restore or to improve binocular vision in cases with large-angle deviations is seriously questioned. 6. Moreover, the disruption of fusion and stereopsis is abrupt and severe and does not parallel the decrease in visual acuity. The severely reduced ability to maintain fusion may be related to the optical aberrations, which, in turn, may be due to the molding process and the polyvinyl chloride molding material. 7. Through the flexibility of the membrane prism is a definite advantage, because of its proclivity to reduce visual acuity and increase aberrations its prescription for adults often must be limited to only one eye. 8. For the same reasons in the young child with binocular vision problems, the membrane prism presently available should be prescribed over both eyes only in powers less than 20 delta. When the membrane prism is to be used as a partial occluder (over one eye only), any power can be used. 9. The new Fresnel "hard" prism reduces visual acuity minimally and rarely disrupts binocularity, thus increasing the potential for prismotherapy to establish binocularity. This

  15. Human Time-Frequency Acuity Beats the Fourier Uncertainty Principle

    NASA Astrophysics Data System (ADS)

    Oppenheim, Jacob N.; Magnasco, Marcelo O.

    2013-01-01

    The time-frequency uncertainty principle states that the product of the temporal and frequency extents of a signal cannot be smaller than 1/(4π). We study human ability to simultaneously judge the frequency and the timing of a sound. Our subjects often exceeded the uncertainty limit, sometimes by more than tenfold, mostly through remarkable timing acuity. Our results establish a lower bound for the nonlinearity and complexity of the algorithms employed by our brains in parsing transient sounds, rule out simple “linear filter” models of early auditory processing, and highlight timing acuity as a central feature in auditory object processing.

  16. Human time-frequency acuity beats the Fourier uncertainty principle.

    PubMed

    Oppenheim, Jacob N; Magnasco, Marcelo O

    2013-01-25

    The time-frequency uncertainty principle states that the product of the temporal and frequency extents of a signal cannot be smaller than 1/(4 π). We study human ability to simultaneously judge the frequency and the timing of a sound. Our subjects often exceeded the uncertainty limit, sometimes by more than tenfold, mostly through remarkable timing acuity. Our results establish a lower bound for the nonlinearity and complexity of the algorithms employed by our brains in parsing transient sounds, rule out simple "linear filter" models of early auditory processing, and highlight timing acuity as a central feature in auditory object processing.

  17. Effects of posterior segment disorders on oscillatory displacement thresholds, and on acuities as measured using the potential acuity meter and laser interferometer.

    PubMed

    Barrett, B T; Davison, P A; Eustace, P E

    1994-04-01

    Oscillatory displacement thresholds (ODTs) were measured in 67 subjects with clear ocular media, but known posterior segment disorders. The ability of these thresholds to assess reduced visual function, as quantified by visual acuity deficits, was compared with that of the Potential Acuity Meter (PAM) and the Rodenstock Retinometer (RR). ODTs were found to be sensitive to acuity deficits which were retinal/neural in origin. Despite the fact that interferometric acuities are, unlike ODTs, a measure of resolution, the RR proved no more accurate in assessing the level of letter acuity which existed than did ODT measurement. As would be expected, the PAM provided for the most accurate means of assessing non-optical visual acuity deficits. However, the PAM proved to be less useful in eyes with: very poor levels of acuity, and certain anomalous conditions. The results have implications for the relative ability of each of the three tests to identify reduced visual function behind cataract.

  18. Comparison of the STYCAR and lighthouse acuity tests.

    PubMed

    Kastenbaum, S M; Kepford, K L; Holmstrom, E T

    1977-07-01

    In a study comparing the Screening Test for Young Children and Retardates (STYCAR) and the New York Lighthouse Flash Card Test, 50 preschool children (median age of 4.4 yr) were evaluated twice with each instrument. Results indicate that the Lighthouse test had higher reliability, better visual acuity scores, lower untestability rates, and shorter testing times than the STYCAR.

  19. Degraded Time-Frequency Acuity to Time-Reversed Notes

    PubMed Central

    Oppenheim, Jacob N.; Isakov, Pavel; Magnasco, Marcelo O.

    2013-01-01

    Time-reversal symmetry breaking is a key feature of many classes of natural sounds, originating in the physics of sound production. While attention has been paid to the response of the auditory system to “natural stimuli,” very few psychophysical tests have been performed. We conduct psychophysical measurements of time-frequency acuity for stylized representations of “natural”-like notes (sharp attack, long decay) and the time-reversed versions of these notes (long attack, sharp decay). Our results demonstrate significantly greater precision, arising from enhanced temporal acuity, for such sounds over their time-reversed versions, without a corresponding decrease in frequency acuity. These data inveigh against models of auditory processing that include tradeoffs between temporal and frequency acuity, at least in the range of notes tested and suggest the existence of statistical priors for notes with a sharp-attack and a long-decay. We are additionally able to calculate a minimal theoretical bound on the sophistication of the nonlinearities in auditory processing. We find that among the best studied classes of nonlinear time-frequency representations, only matching pursuit, spectral derivatives, and reassigned spectrograms are able to satisfy this criterion. PMID:23799012

  20. Electrophysiological Correlates of Vernier Acuity in Human Visual Cortex.

    DTIC Science & Technology

    1984-04-28

    Ia ) VEPs evoked bj vernier offset stimuli couldbe used to estimate 7 LL- psychophysical threshold, b VEP amplitude was affected by interference lines...absolute accuracy. Relative estimate accuracy is judged by the criteria of the estimates being much less than the resolution acuity predicted by anato - mical

  1. Acuity systems dialogue and patient classification system essentials.

    PubMed

    Harper, Kelle; McCully, Crystal

    2007-01-01

    Obtaining resources for quality patient care is a major responsibility of nurse leaders and requires accurate information in the political world of budgeting. Patient classification systems (PCS) assist nurse managers in controlling cost and improving patient care while appropriately using financial resources. This paper communicates acuity systems development, background, flaws, and components while discussing a few tools currently available. It also disseminates the development of a new acuity tool, the Patient Classification System. The PCS tool, developed in a small rural hospital, uses 5 broad concepts: (1) medications, (2) complicated procedures, (3) education, (4) psychosocial issues, and (5) complicated intravenous medications. These concepts embrace a 4-tiered scale that differentiates significant patient characteristics and assists in staffing measures for equality in patient staffing and improving quality of care and performance. Data obtained through use of the PCS can be used by nurse leaders to effectively and objectively lobby for appropriate patient care resources. Two questionnaires distributed to registered nurses on a medical-surgical unit evaluated the nurses' opinion of the 5 concepts and the importance for establishing patient acuity for in-patient care. Interrater reliability among nurses was 87% with the author's acuity tool.

  2. Spatial contrast sensitivity and grating acuity of barn owls.

    PubMed

    Harmening, Wolf M; Nikolay, Petra; Orlowski, Julius; Wagner, Hermann

    2009-07-22

    The eyes of barn owls (Tyto alba pratincola) display very little aberrations, and have thus excellent optical quality. In a series of behavioral experiments, we tested whether this presumably beneficial feature is also reflected at a perceptual level in this species. As fundamental indicators for visual performance, the spatial contrast sensitivity function (CSF) and grating acuity were measured in two barn owls with psychophysical techniques. Stimulus luminance was 2.7 cd/m(2). The CSF found here renders the typical band-limited, inverted U-shaped function, with a low maximum contrast sensitivity of 8-19 at a spatial frequency of 1 cyc/deg. Grating acuity was estimated from the CSF high frequency cut-off and yielded 3.0-3.7 cyc/deg. In a second experiment, in which contrast was held constant and spatial frequency was varied, grating acuity was measured directly (2.6-4.0 cyc/deg). These results put barn owls at the very low end of the visual acuity spectrum of birds, and demonstrate that visual resolution and sensitivity cannot be predicted by optical considerations alone.

  3. On Using Vernier Acuity to Assess Magnocellular Sensitivity

    ERIC Educational Resources Information Center

    Skottun, Bernt C.; Skoyles, John R.

    2010-01-01

    A recent study [Keri, S., & Benedek, G. (2009). Visual pathway deficit in female fragile x premutation carriers: A potential endophenotype. "Brain and Cognition", 69, 291-295] has found Vernier acuity deficiencies together with contrast sensitivity defects consistent with a magnocellular deficit in female fragile x premutation carriers. This may…

  4. Arithmetic Training Does Not Improve Approximate Number System Acuity

    PubMed Central

    Lindskog, Marcus; Winman, Anders; Poom, Leo

    2016-01-01

    The approximate number system (ANS) is thought to support non-symbolic representations of numerical magnitudes in humans. Recently much debate has focused on the causal direction for an observed relation between ANS acuity and arithmetic fluency. Here we investigate if arithmetic training can improve ANS acuity. We show with an experimental training study consisting of six 45-min training sessions that although feedback during arithmetic training improves arithmetic performance substantially, it does not influence ANS acuity. Hence, we find no support for a causal link where symbolic arithmetic training influences ANS acuity. Further, although short-term number memory is likely involved in arithmetic tasks we did not find that short-term memory capacity for numbers, measured by a digit-span test, was effected by arithmetic training. This suggests that the improvement in arithmetic fluency may have occurred independent of short-term memory efficiency, but rather due to long-term memory processes and/or mental calculation strategy development. The theoretical implications of these findings are discussed. PMID:27826270

  5. A Comparison of Patched HOTV Visual Acuity and Photoscreening

    ERIC Educational Resources Information Center

    Leman, Rachel; Clausen, Michelle M.; Bates, Janice; Stark, Lee; Arnold, Koni K.; Arnold, Robert W.

    2006-01-01

    Early detection of significant vision problems in children is a high priority for pediatricians and school nurses. Routine vision screening is a necessary part of that detection and has traditionally involved acuity charts. However, photoscreening in which "red eye" is elicited to show whether each eye is focusing may outperform routine acuity…

  6. THE RELATION BETWEEN VISUAL ACUITY AND BRIGHTNESS DISCRIMINATION

    PubMed Central

    Hendley, Charles D.

    1948-01-01

    1. Visual acuity depends on the brightness contrast between test object and background; and conversely, brightness discrimination depends on the target size. Both functions vary with the brightness of the background. Measurements with rectangular targets of length-width ratio 2 were made over a range of sizes, contrasts, and brightnesses sufficient to determine the relations among these three variables. The rectangles were from 2' to 50' wide; the contrast fraction, ΔI/I, ranged from 0.01 to 40; the background brightness varied from 0.0001 to 2500 millilamberts. 2. When ΔI/I or visual acuity is plotted as a function of brightness the data do, in general, follow Hecht's equation. The departure from a simple photochemical theory which the larger targets show is probably due to changes in the functional retinal mosaic with changing brightness. 3. In general also, the relation between visual acuity and brightness, at selected contrasts, fits Hecht's derivation. At low contrasts, as the brightness is reduced a point is reached at which the test object becomes invisible at any size. 4. No simple relation emerges from the data relating visual acuity to contrast, at set levels of illumination. Over only a very short range are visual acuity and contrast directly related. At high contrasts, visual acuity reaches a maximum, whereas at low visual acuity, ΔI/I reaches a minimum which cannot be passed regardless of size. 5. The shape of the curves relating ΔI/I to brightness is not significantly altered by changing the exposure time. There is some evidence to show that a 3 second exposure of the target is equivalent to two looks of 0.2 second each. 6. In all these studies the thresholds were determined by a frequency of seeing method, and the data have been considered in terms of a quantum theory of threshold seeing. It was found that a threshold response involves between four and eight independent critical events, which are largely independent of size, brightness, and

  7. Dynamic Visual Acuity: a Functionally Relevant Research Tool

    NASA Technical Reports Server (NTRS)

    Peters, Brian T.; Brady, Rachel A.; Miller, Chris A.; Mulavara, Ajitkumar P.; Wood, Scott J.; Cohen, Helen S.; Bloomberg, Jacob J.

    2010-01-01

    Coordinated movements between the eyes and head are required to maintain a stable retinal image during head and body motion. The vestibulo-ocular reflex (VOR) plays a significant role in this gaze control system that functions well for most daily activities. However, certain environmental conditions or interruptions in normal VOR function can lead to inadequate ocular compensation, resulting in oscillopsia, or blurred vision. It is therefore possible to use acuity to determine when the environmental conditions, VOR function, or the combination of the two is not conductive for maintaining clear vision. Over several years we have designed and tested several tests of dynamic visual acuity (DVA). Early tests used the difference between standing and walking acuity to assess decrements in the gaze stabilization system after spaceflight. Supporting ground-based studies measured the responses from patients with bilateral vestibular dysfunction and explored the effects of visual target viewing distance and gait cycle events on walking acuity. Results from these studies show that DVA is affected by spaceflight, is degraded in patients with vestibular dysfunction, changes with target distance, and is not consistent across the gait cycle. We have recently expanded our research to include studies in which seated subjects are translated or rotated passively. Preliminary results from this work indicate that gaze stabilization ability may differ between similar active and passive conditions, may change with age, and can be affected by the location of the visual target with respect to the axis of motion. Use of DVA as a diagnostic tool is becoming more popular but the functional nature of the acuity outcome measure also makes it ideal for identifying conditions that could lead to degraded vision. By doing so, steps can be taken to alter the problematic environments to improve the man-machine interface and optimize performance.

  8. Sound Localization Acuity and its Relation to Vision in Large and Small Fruit-eating Bats: II. Non-echolocating Species, Eidolon helvum and Cynopterus brachyotis

    PubMed Central

    Heffner, R.S.; Koay, G.; Heffner, H.E.

    2008-01-01

    Passive sound-localization acuity for 100-msec noise bursts was determined behaviorally for two species of non-echolocating bats: the Straw-colored fruit bat, Eidolon helvum, a large frugivore, and the Dog-faced fruit bat, Cynopterus brachyotis, a small frugivore. The mean minimum audible angle for two E. helvum was 11.7°, and for two C. brachyotis was 10.5°. This places their passive sound-localization acuity near the middle of the range for echolocating bats as well as the middle of the range for other mammals. Sound-localization acuity varies widely among mammals, and the best predictor of this auditory function remains the width of the field of best vision (r = .89, p < .0001). Among echolocating and non-echolocating bats, as well as among other mammals, the use of hearing to direct the eyes to the source of a sound still appears to serve as an important selective factor for sound localization. Absolute visual acuity and the magnitude of the binaural locus cues available to a species remain unreliable predictors of sound-localization acuity. PMID:18571883

  9. THE VISUAL ACUITY AND INTENSITY DISCRIMINATION OF DROSOPHILA

    PubMed Central

    Hecht, Selig; Wald, George

    1934-01-01

    Drosophila possesses an inherited reflex response to a moving visual pattern which can be used to measure its capacity for intensity discrimination and its visual acuity at different illuminations. It is found that these two properties of vision run approximately parallel courses as functions of the prevailing intensity. Visual acuity varies with the logarithm of the intensity in much the same sigmoid way as in man, the bee, and the fiddler crab. The resolving power is very poor at low illuminations and increases at high illuminations. The maximum visual acuity is 0.0018, which is 1/1000 of the maximum of the human eye and 1/10 that of the bee. The intensity discrimination of Drosophila is also extremely poor, even at its best. At low illuminations for two intensities to be recognized as different, the higher must be nearly 100 times the lower. This ratio decreases as the intensity increases, and reaches a minimum of 2.5 which is maintained at the highest intensities. The minimum value of ΔI/I for Drosophila is 1.5, which is to be compared with 0.25 for the bee and 0.006 for man. An explanation of the variation of visual acuity with illumination is given in terms of the variation in number of elements functional in the retinal mosaic at different intensities, this being dependent on the general statistical distribution of thresholds in the ommatidial population. Visual acuity is thus determined by the integral form of this distribution and corresponds to the total number of elements functional. The idea that intensity discrimination is determined by the differential form of this distribution—that is, that it depends on the rate of entrance of functional elements with intensity—is shown to be untenable in the light of the correspondence of the two visual functions. It is suggested that, like visual acuity, intensity discrimination may also have to be considered as a function of the total number of elements active at a given intensity. PMID:19872798

  10. Lumbar position sense acuity during an electrical shock stressor

    PubMed Central

    Hjortskov, Nis; Hye-Knudsen, Christian; Fallentin, Nils

    2005-01-01

    Background Optimal motor control of the spine depends on proprioceptive input as a prerequisite for co-ordination and the stability of the spine. Muscle spindles are known to play an important role in proprioception. Animal experiments suggest that an increase in sympathetic outflow can depress muscle spindle sensitivity. As the muscle spindle may be influenced by sympathetic modulation, we hypothesized that a state of high sympathetic activity as during mental stress would affect the proprioceptive output from the muscle spindles in the back muscles leading to alterations in proprioception and position sense acuity. The aim was to investigate the effect of mental stress, in this study the response to an electrical shock stressor, on position sense acuity in the rotational axis of the lumbar spine. Methods Passive and active position sense acuity in the rotational plane of the lumbar spine was investigated in the presence and absence of an electrical shock stressor in 14 healthy participants. An electrical shock-threat stressor lasting for approximately 12 minutes was used as imposed stressor to build up a strong anticipatory arousal: The participants were told that they were going to receive 8 painful electrical shocks however the participants never received the shocks. To quantify the level of physiological arousal and the level of sympathetic outflow continuous beat-to-beat changes in heart rate (beats*min-1) and systolic, diastolic and mean arterial blood pressure (mmHg) were measured. To quantify position sense acuity absolute error (AE) expressed in degrees was measured. Two-way analysis of variance with repeated measurements (subjects as random factor and treatments as fixed factors) was used to compare the different treatments. Results Significant increases were observed in systolic blood pressure, diastolic blood pressure, and heart rate during the stress sessions indicating elevated sympathetic activity (15, 14 and 10%, respectively). Despite pronounced

  11. Herniated disks unchanged over time: Size reduced after oxygen-ozone therapy.

    PubMed

    Bonetti, Matteo; Zambello, Alessio; Leonardi, Marco; Princiotta, Ciro

    2016-08-01

    The spontaneous regression of disk herniation secondary to dehydration is a much-debated topic in medicine. Some physicians wonder whether surgical removal of the extruded nucleus pulposus is really necessary when the spontaneous disappearance of a herniated lumbar disk is a well-known phenomenon. Unfortunately, without spontaneous regression, chronic pain leads to progressive disability for which surgery seems to be the only solution. In recent years, several studies have demonstrated the utility of oxygen-ozone therapy in the treatment of disk herniation, resulting in disk shrinkage. This retrospective study evaluates the outcomes of a series of patients with a history of herniated disks neuroradiologically unchanged in size for over two years, treated with oxygen-ozone therapy at our center over the last 15 years. We treated 96 patients, 84 (87.5%) presenting low back pain complicated or not by chronic sciatica. No drug therapy had yielded significant benefits. A number of specialists had been consulted in two or more years resulting in several neuroradiological scans prior to the decision to undertake oxygen-ozone therapy. Our study documents how ozone therapy for slipped disks "unchanged over time" solved the problem, with disk disruption or a significant reduction in the size of the prolapsed disk material extruded into the spinal canal.

  12. Assessment of Visual Acuity in Relation to Central Nervous System Activation in Children with Mental Retardation.

    ERIC Educational Resources Information Center

    Jacobsen, Karl; Grottland, Havar; Flaten, Magne Arve

    2001-01-01

    Assessment of visual acuity, using Teller Acuity Cards, was combined with observations of behavioral state to indicate central nervous system activation in 24 individuals with mental retardation. Results indicate that forced-choice preferential-looking technique can be used to test visual acuity in this population unless the participant is drowsy.…

  13. Influence of loupes and age on the near visual acuity of practicing dentists

    NASA Astrophysics Data System (ADS)

    Eichenberger, Martina; Perrin, Philippe; Neuhaus, Klaus W.; Bringolf, Ueli; Lussi, Adrian

    2011-03-01

    We evaluated the near visual acuity of 40 dentists and its improvement by using different magnification devices. The acuity was tested with miniaturized E-optotype tests on a negatoscope under the following conditions: 1. natural visual acuity, 300 mm; 2. single lens loupe, 2×, 250 mm; 3. Galilean loupe, 2.5×, 380 mm; and 4. Keplerian loupe, 4.3×, 400 mm. In part 1, the influence of the magnification devices was investigated for all dentists. The Keplerian loupe obtained the highest visual acuity (4.64), followed by the Galilean loupe (2.43), the single lens loupe (1.42), and natural visual acuity (1.19). For part 2, the dentists were classified according to their age (=40 years). The younger dentists' group achieved a significantly higher visual acuity with all magnification devices (p<0.001). For part 3, the dentists were grouped according to their natural visual acuity. The group with the higher natural visual acuity achieved significantly higher visual acuity with all magnification devices than did the group of dentists with the lower natural visual acuity (p<0.01). It can be concluded that near visual acuity varies highly between individuals and decreases during the lifetime. Independent of age or natural vision, visual acuity can be significantly improved by using magnification devices.

  14. Visual acuity with reversed-contrast charts: II. Clinical investigation.

    PubMed

    Westheimer, Gerald; Chu, Patricia; Huang, Wendy; Tran, Thuy; Dister, Robert

    2003-11-01

    Snellen visual acuity was measured in 106 patients ranging in age from 20 to 88 years in routine examinations in the general refraction clinic with two kinds of charts: the standard chart using black letters on a white background and a reversed-contrast display featuring white letters on a black background. The overall ratio of the white-on-black to the black-on-white Snellen fractions was 1.043. A scattergram relating this ratio to patient age revealed that the older the patient, the more the visual acuity was improved by switching to the reversed-contrast chart, with a regression line slope of 0.5 +/- 0.10. Impairment of the eye's optics, in particular by intraocular scatter causing a widening and flattening of the eye's point-spread function, explains these findings and suggests prognostic and therapeutic value of reversing the contrast polarity of displays.

  15. Evaluation of visual acuity with Gen 3 night vision goggles

    NASA Technical Reports Server (NTRS)

    Bradley, Arthur; Kaiser, Mary K.

    1994-01-01

    Using laboratory simulations, visual performance was measured at luminance and night vision imaging system (NVIS) radiance levels typically encountered in the natural nocturnal environment. Comparisons were made between visual performance with unaided vision and that observed with subjects using image intensification. An Amplified Night Vision Imaging System (ANVIS6) binocular image intensifier was used. Light levels available in the experiments (using video display technology and filters) were matched to those of reflecting objects illuminated by representative night-sky conditions (e.g., full moon, starlight). Results show that as expected, the precipitous decline in foveal acuity experienced with decreasing mesopic luminance levels is effectively shifted to much lower light levels by use of an image intensification system. The benefits of intensification are most pronounced foveally, but still observable at 20 deg eccentricity. Binocularity provides a small improvement in visual acuity under both intensified and unintensified conditions.

  16. Impact of visual acuity on developing literacy at age 4–5 years: a cohort-nested cross-sectional study

    PubMed Central

    Bruce, Alison; Fairley, Lesley; Chambers, Bette; Wright, John; Sheldon, Trevor A

    2016-01-01

    Objectives To estimate the prevalence of poor vision in children aged 4–5 years and determine the impact of visual acuity on literacy. Design Cross-sectional study linking clinical, epidemiological and education data. Setting Schools located in the city of Bradford, UK. Participants Prevalence was determined for 11 186 children participating in the Bradford school vision screening programme. Data linkage was undertaken for 5836 Born in Bradford (BiB) birth cohort study children participating both in the Bradford vision screening programme and the BiB Starting Schools Programme. 2025 children had complete data and were included in the multivariable analyses. Main outcome measures Visual acuity was measured using a logMAR Crowded Test (higher scores=poorer visual acuity). Literacy measured by Woodcock Reading Mastery Tests-Revised (WRMT-R) subtest: letter identification (standardised). Results The mean (SD) presenting visual acuity was 0.14 (0.09) logMAR (range 0.0–1.0). 9% of children had a presenting visual acuity worse than 0.2logMAR (failed vision screening), 4% worse than 0.3logMAR (poor visual acuity) and 2% worse than 0.4logMAR (visually impaired). Unadjusted analysis showed that the literacy score was associated with presenting visual acuity, reducing by 2.4 points for every 1 line (0.10logMAR) reduction in vision (95% CI −3.0 to −1.9). The association of presenting visual acuity with the literacy score remained significant after adjustment for demographic and socioeconomic factors reducing by 1.7 points (95% CI −2.2 to −1.1) for every 1 line reduction in vision. Conclusions Prevalence of decreased visual acuity was high compared with other population-based studies. Decreased visual acuity at school entry is associated with reduced literacy. This may have important implications for the children's future educational, health and social outcomes. PMID:26883240

  17. Heterogeneity of failure of visual acuity in Graves' disease.

    PubMed Central

    Sachdev, Y.; Chatterji, J. C.; Sharma, R. C.

    1979-01-01

    The eye manifestations of Graves' disease are usually mild and self-limiting. Occasionally they follow a progressive course leading to visual loss and total blindness. The ocular manifestations bear no relationship to the metabolic state and may appear before, during or after onset of thyrotoxicosis. Characteristically they become evident at about the time of onset of hypermetabolism. Various factors responsible for the failure of visual acuity are discussed with case illustrations. PMID:314108

  18. Eye size and visual acuity influence vestibular anatomy in mammals.

    PubMed

    Kemp, Addison D; Christopher Kirk, E

    2014-04-01

    The semicircular canals of the inner ear detect head rotations and trigger compensatory movements that stabilize gaze and help maintain visual fixation. Mammals with large eyes and high visual acuity require precise gaze stabilization mechanisms because they experience diminished visual functionality at low thresholds of uncompensated motion. Because semicircular canal radius of curvature is a primary determinant of canal sensitivity, species with large canal radii are expected to be capable of more precise gaze stabilization than species with small canal radii. Here, we examine the relationship between mean semicircular canal radius of curvature, eye size, and visual acuity in a large sample of mammals. Our results demonstrate that eye size and visual acuity both explain a significant proportion of the variance in mean canal radius of curvature after statistically controlling for the effects of body mass and phylogeny. These findings suggest that variation in mean semicircular canal radius of curvature among mammals is partly the result of selection for improved gaze stabilization in species with large eyes and acute vision. Our results also provide a possible functional explanation for the small semicircular canal radii of fossorial mammals and plesiadapiforms.

  19. Effects of Horizontal Acceleration on Human Visual Acuity and Stereopsis

    PubMed Central

    Horng, Chi-Ting; Hsieh, Yih-Shou; Tsai, Ming-Ling; Chang, Wei-Kang; Yang, Tzu-Hung; Yauan, Chien-Han; Wang, Chih-Hung; Kuo, Wu-Hsien; Wu, Yi-Chang

    2015-01-01

    The effect of horizontal acceleration on human visual acuity and stereopsis is demonstrated in this study. Twenty participants (mean age 22.6 years) were enrolled in the experiment. Acceleration from two different directions was performed at the Taiwan High-Speed Rail Laboratory. Gx and Gy (< and >0.1 g) were produced on an accelerating platform where the subjects stood. The visual acuity and stereopsis of the right eye were measured before and during the acceleration. Acceleration <0.1 g in the X- or Y-axis did not affect dynamic vision and stereopsis. Vision decreased (mean from 0.02 logMAR to 0.25 logMAR) and stereopsis declined significantly (mean from 40 s to 60.2 s of arc) when Gx > 0.1 g. Visual acuity worsened (mean from 0.02 logMAR to 0.19 logMAR) and poor stereopsis was noted (mean from 40 s to 50.2 s of arc) when Gy > 0.1 g. The effect of acceleration from the X-axis on the visual system was higher than that from the Y-axis. During acceleration, most subjects complained of ocular strain when reading. To our knowledge, this study is the first to report the exact levels of visual function loss during Gx and Gy. PMID:25607601

  20. Effects of horizontal acceleration on human visual acuity and stereopsis.

    PubMed

    Horng, Chi-Ting; Hsieh, Yih-Shou; Tsai, Ming-Ling; Chang, Wei-Kang; Yang, Tzu-Hung; Yauan, Chien-Han; Wang, Chih-Hung; Kuo, Wu-Hsien; Wu, Yi-Chang

    2015-01-19

    The effect of horizontal acceleration on human visual acuity and stereopsis is demonstrated in this study. Twenty participants (mean age 22.6 years) were enrolled in the experiment. Acceleration from two different directions was performed at the Taiwan High-Speed Rail Laboratory. Gx and Gy (< and >0.1 g) were produced on an accelerating platform where the subjects stood. The visual acuity and stereopsis of the right eye were measured before and during the acceleration. Acceleration <0.1 g in the X- or Y-axis did not affect dynamic vision and stereopsis. Vision decreased (mean from 0.02 logMAR to 0.25 logMAR) and stereopsis declined significantly (mean from 40 s to 60.2 s of arc) when Gx > 0.1 g. Visual acuity worsened (mean from 0.02 logMAR to 0.19 logMAR) and poor stereopsis was noted (mean from 40 s to 50.2 s of arc) when Gy > 0.1 g. The effect of acceleration from the X-axis on the visual system was higher than that from the Y-axis. During acceleration, most subjects complained of ocular strain when reading. To our knowledge, this study is the first to report the exact levels of visual function loss during Gx and Gy.

  1. Higher Cognitive Function in Elderly Individuals with Previous Cataract Surgery: Cross-Sectional Association Independent of Visual Acuity in the HEIJO-KYO Cohort.

    PubMed

    Miyata, Kimie; Obayashi, Kenji; Saeki, Keigo; Tone, Nobuhiro; Tanaka, Kunihiko; Nishi, Tomo; Morikawa, Masayuki; Kurumatani, Norio; Ogata, Nahoko

    2016-06-01

    Cataract surgery improves visual acuity and drastically increases the capacity for light reception to the retina. Although previous studies suggested that both light exposure and visual acuity were associated with cognitive function, the relationships between cataract surgery, visual acuity, and cognitive function have not been evaluated in large populations. In this cross-sectional study, we measured cognitive function using the Mini-Mental State Examination and best-corrected visual acuity in pseudophakic (previous cataract surgery) and phakic (no previous cataract surgery) elderly individuals. Of 945 participants (mean age 71.7 years), 166 (17.6%) had pseudophakia and 317 (33.5%) had impaired cognitive function (score ≤26). The pseudophakic group showed significantly better visual acuity than the phakic group (p = 0.003) and lower age-adjusted odds ratio (ORs) for cognitive impairment (OR 0.66; p = 0.038). Consistently, in multivariate logistic regression models, after adjusting for confounding factors, including visual acuity and socioeconomic status, ORs for cognitive impairment were significantly lower in the pseudophakic group than in the phakic group (OR 0.64; 95% confidence interval 0.43-0.96; p = 0.031). This association remained significant in sensitivity analysis, excluding participants with low cognitive score ≤23 (n = 36). In conclusion, in a general elderly population, prevalence of cognitive impairment was significantly lower in pseudophakic individuals independently of visual acuity. The association was also independent of several major causes of cognitive impairment such as aging, gender, obesity, socioeconomic status, hypertension, diabetes, sleep disturbances, depressive symptoms, and physical inactivity.

  2. VCD study of alpha-methylbenzyl amine derivatives: detection of the unchanged chiral motif.

    PubMed

    Merten, Christian; Amkreutz, Marc; Hartwig, Andreas

    2010-08-01

    Chiral alpha-methylbenzyl amine is a well known and often used chiral auxiliary, e.g., in the resolution of racemates or asymmetric catalysis. In this work, alpha-methylbenzyl amine and its derivatives N,alpha-dimethylbenzyl amine, N,N,alpha-trimethylbenzyl amine, and bis[alpha-methylbenzyl] amine were investigated by vibrational circular dichroism (VCD) spectroscopy and density functional theory (DFT). For all compounds, stable low energy conformers were obtained by the DFT calculations and based on those, the theoretical vibrational absorption (VA) and VCD spectra were calculated and compared with experimental spectra. Hence, the absolute configurations and conformational preferences were determined. A qualitative comparison of all the experimental VCD spectra of the investigated chiral molecules supported by the calculated ones is given which clearly shows similarities between the spectra of the different chiral amines. These can be assigned to vibrations of the unchanged chiral center.

  3. Distance stereo acuity improvement in intermittent exotropic patients following strabismus surgery.

    PubMed

    O'Neal, T D; Rosenbaum, A L; Stathacopoulos, R A

    1995-01-01

    To determine whether distance stereo acuity improved following strabismus surgery in patients with intermittent exotropia, we tested 20 patients (5 to 87 years old) preoperatively and postoperatively using the Mentor BVAT II Video acuity tester (Santa Barbara, Calif) and binocular visual system. Acuity improved in 75% as assessed by contour circles and in 45% as assessed by random dot E tests at distance. Our results suggest that surgical realignment of intermittent exotropia restores distance stereo acuity. We conclude that measuring distance stereo acuity offers valuable information in the evaluation of the intermittent exotropic patient.

  4. Unchanged incidence and increased survival in children with neuroblastoma in Denmark 1981–2000: a population-based study

    PubMed Central

    Schroeder, H; Wacher, J; Larsson, H; Rosthoej, S; Rechnitzer, C; Pedersen, B L; Carlsen, N L T

    2009-01-01

    Treatment results for neuroblastoma in Denmark have been poorer than in other Nordic countries, so we investigated whether a change in incidence, stage distribution and survival had occurred between 1981 and 2000. Clinical data were retrieved from the medical charts of 160 children <15 years of age with extra-cranial neuroblastoma (n=139) or ganglioneuroblastoma (n=21) diagnosed in Denmark between 1981 and 2000. The minimal follow-up time was 52 months. Statistical analyses were performed in STATA. The incidence was 8.55 per million children below 15 years of age (world standard 9.6) and 42.6 per million children below 12 months of age, and it has remained unchanged since 1970. The median age at diagnosis was 27 months. In all, 32% of the children were aged below 12 months at diagnosis, 53% had metastatic disease and in 12% the diagnosis was made incidentally. Prognostic factors such as age, stage and site of primary tumour were the same as in other studies and did not change. During the study period, the mortality rate decreased steadily, and the 5-year survival rate increased from 38% in 1981–1985 to 59% in 1996–2000, corresponding to the level found in other Western countries. Increased survival was also seen in children with metastatic disease. Participation in international studies, better supportive care and possibly postoperative autologous stem cell transplantation may have contributed to the increased survival. PMID:19223904

  5. Sound Localization Acuity and its Relation to Vision in Large and Small Fruit-eating Bats: I. Echolocating Species, Phyllostomus hastatus and Carollia perspicillata

    PubMed Central

    Heffner, R.S.; Koay, G.; Heffner, H.E.

    2007-01-01

    Passive sound-localization acuity for 100-msec noise bursts was determined behaviorally for two species of bats: Phyllostomus hastatus, a large bat that eats fruit and vertebrates, and Carollia perspicillata, a small species that eats fruit and nectar. The mean minimum audible angle for two P. hastatus was 9°, and that for two C. perspicillata was 14.8°. This places their passive sound-localization acuity near the middle of the range for mammals. Sound localization varies widely among mammals and the best predictor of a species’ acuity remains the width of the field of best vision (r = .89, p < .0001). The five echolocating bats that have been tested do not deviate from this relationship suggesting that despite their specialization for echolocation, the use of hearing to direct the eyes to the source of a sound still serves as an important selective factor for sound localization. PMID:17630232

  6. Concentration and density changes at an electrode surface and the principle of unchanging total concentration

    DOE PAGES

    Stephen W. Feldberg; Lewis, Ernie R.

    2016-02-17

    In this study, the principle of unchanging total concentration as described by Oldham and Feldberg [J. Phys. Chem. B, 103, 1699 (1999)] is invoked to analyze systems comprising a redox pair (Xz11 and Xz22) plus one or more non-electroactive species (Xz33,Xz44...Xzjmaxjmax) where Xzjj is the jth species with charge zj and concentration; cj. The principle states that if the diffusion coefficients for all species are identical and mass transport is governed by the Nernst-Planck expression, the total concentration does not change during any electrochemical perturbation, i.e.: Σjmaxj=1[Xzjj]=Σjmaxj=1 cj = SP With this principle we deduce the electrochemically induced difference betweenmore » the surface and bulk concentrations for each species. Those concentration differences are translated into density differences which are a function of the density of the solvent and of the concentration differences, molecular masses and the standard partial molar volumes of all species. Those density differences in turn can induce convection that will ultimately modify the observed current. However, we did not attempt to quantify details of the natural convection and current modification produced by those density differences.« less

  7. Measuring acuity of the approximate number system reliably and validly: the evaluation of an adaptive test procedure

    PubMed Central

    Lindskog, Marcus; Winman, Anders; Juslin, Peter; Poom, Leo

    2013-01-01

    Two studies investigated the reliability and predictive validity of commonly used measures and models of Approximate Number System acuity (ANS). Study 1 investigated reliability by both an empirical approach and a simulation of maximum obtainable reliability under ideal conditions. Results showed that common measures of the Weber fraction (w) are reliable only when using a substantial number of trials, even under ideal conditions. Study 2 compared different purported measures of ANS acuity as for convergent and predictive validity in a within-subjects design and evaluated an adaptive test using the ZEST algorithm. Results showed that the adaptive measure can reduce the number of trials needed to reach acceptable reliability. Only direct tests with non-symbolic numerosity discriminations of stimuli presented simultaneously were related to arithmetic fluency. This correlation remained when controlling for general cognitive ability and perceptual speed. Further, the purported indirect measure of ANS acuity in terms of the Numeric Distance Effect (NDE) was not reliable and showed no sign of predictive validity. The non-symbolic NDE for reaction time was significantly related to direct w estimates in a direction contrary to the expected. Easier stimuli were found to be more reliable, but only harder (7:8 ratio) stimuli contributed to predictive validity. PMID:23964256

  8. Evaluation of vernier acuity near healed retinal laser lesions

    NASA Astrophysics Data System (ADS)

    Schmeisser, Elmar T.

    1997-05-01

    Seven Cynomolgus fasciculata who had graded laser lesions placed in own eye 6 years previously were evaluated for their vernier acuity by electrophysiologic recording techniques. In these experiments, 95 percent contrast vernier acuity targets were presented at high luminance levels to anesthetized primates. Visual evoked potentials were recorded by conventional means form scalp electrodes through hospital grade amplifiers. All animal testing was performed under IACUC approved protocols. The single q-switched pulses form a neodymium-YAG laser had produced lesions of 4 types: no visible change, minimal visible lesions, 'white dot' lesions and 'red dot' lesions in the eye at the time of placement. Single exposures had been made in four locations: 5 degrees superior, inferior and temporal to the fovea, and one foveally. Vernier recording proved somewhat successful in smaller animals with less than contained retinal hemorrhage lesions in the fovea. Initial analyses demonstrated a significant decrease of the pattern response signal/noise in the experimental eye overall, and an apparent relative loss of vernier signal in some lesioned eyes. Animals with the more severe lesions have somewhat degraded small patten responses and no recordable vernier response. Apparent lesser losses produced less effect.

  9. Influence of intraocular lens subsurface nanoglistenings on functional visual acuity

    PubMed Central

    Miyata, Kazunori; Hayashidera, Takeshi; Iida, Masaharu; Takada, Keita; Minami, Keiichiro; Oshika, Tetsuro

    2017-01-01

    To investigate the influence of intraocular lens subsurface nanoglistenings (SSNGs) on functional visual acuity (FVA), thirty-nine eyes of 29 patients were examined in this study. The SSNG group comprised 19 eyes of 14 patients (75.7± 5.4 years, mean ± standard deviation), and the control group comprised 20 eyes of 15 patients (73.6 ± 6.5 years). The SSNGs were diagnosed on the basis of the typical whitish IOL appearance upon slit-lamp examination and results of densitometry regarding surface light scattering using Scheimpflug images. The FVA measurement system (AS-28; Kowa, Aichi, Japan) was used to examine changes in continuous visual acuity (VA) over time, and visual function parameters such as FVA, visual maintenance ratio (VMR), maximum VA, minimum VA, standard deviation of VA, and number of blinks were assessed. The results were compared between the SSNG and control groups, and correlations of FVA parameters with the intensity of surface light scattering, time after surgery, and age were also evaluated. There were significant differences in VMR (P = 0.035) and standard deviation of VAs (P = 0.031) between the two groups, although no significant differences were found in baseline VA, FVA, maximum VA, minimum VA, and number of blinks. None of the FVA parameters showed any significant correlations with the intensity of surface light scattering, time after surgery, or age. There is a possibility that VA is unstable during a continuous gazing task in patients with SSNGs. PMID:28328997

  10. Distinct eye movement patterns enhance dynamic visual acuity

    PubMed Central

    Palidis, Dimitrios J.; Wyder-Hodge, Pearson A.; Fooken, Jolande; Spering, Miriam

    2017-01-01

    Dynamic visual acuity (DVA) is the ability to resolve fine spatial detail in dynamic objects during head fixation, or in static objects during head or body rotation. This ability is important for many activities such as ball sports, and a close relation has been shown between DVA and sports expertise. DVA tasks involve eye movements, yet, it is unclear which aspects of eye movements contribute to successful performance. Here we examined the relation between DVA and the kinematics of smooth pursuit and saccadic eye movements in a cohort of 23 varsity baseball players. In a computerized dynamic-object DVA test, observers reported the location of the gap in a small Landolt-C ring moving at various speeds while eye movements were recorded. Smooth pursuit kinematics—eye latency, acceleration, velocity gain, position error—and the direction and amplitude of saccadic eye movements were linked to perceptual performance. Results reveal that distinct eye movement patterns—minimizing eye position error, tracking smoothly, and inhibiting reverse saccades—were related to dynamic visual acuity. The close link between eye movement quality and DVA performance has important implications for the development of perceptual training programs to improve DVA. PMID:28187157

  11. Changes in brain morphology in albinism reflect reduced visual acuity.

    PubMed

    Bridge, Holly; von dem Hagen, Elisabeth A H; Davies, George; Chambers, Claire; Gouws, Andre; Hoffmann, Michael; Morland, Antony B

    2014-07-01

    Albinism, in humans and many animal species, has a major impact on the visual system, leading to reduced acuity, lack of binocular function and nystagmus. In addition to the lack of a foveal pit, there is a disruption to the routing of the nerve fibers crossing at the optic chiasm, resulting in excessive crossing of fibers to the contralateral hemisphere. However, very little is known about the effect of this misrouting on the structure of the post-chiasmatic visual pathway, and the occipital lobes in particular. Whole-brain analyses of cortical thickness in a large cohort of subjects with albinism showed an increase in cortical thickness, relative to control subjects, particularly in posterior V1, corresponding to the foveal representation. Furthermore, mean cortical thickness across entire V1 was significantly greater in these subjects compared to controls and negatively correlated with visual acuity in albinism. Additionally, the group with albinism showed decreased gyrification in the left ventral occipital lobe. While the increase in cortical thickness in V1, also found in congenitally blind subjects, has been interpreted to reflect a lack of pruning, the decreased gyrification in the ventral extrastriate cortex may reflect the reduced input to the foveal regions of the ventral visual stream.

  12. Concentration and density changes at an electrode surface and the principle of unchanging total concentration

    SciTech Connect

    Stephen W. Feldberg; Lewis, Ernie R.

    2016-02-17

    In this study, the principle of unchanging total concentration as described by Oldham and Feldberg [J. Phys. Chem. B, 103, 1699 (1999)] is invoked to analyze systems comprising a redox pair (Xz11 and Xz22) plus one or more non-electroactive species (Xz33,Xz44...Xzjmaxjmax) where Xzjj is the jth species with charge zj and concentration; cj. The principle states that if the diffusion coefficients for all species are identical and mass transport is governed by the Nernst-Planck expression, the total concentration does not change during any electrochemical perturbation, i.e.: Σjmaxj=1[Xzjj]=Σjmaxj=1 cj = SP With this principle we deduce the electrochemically induced difference between the surface and bulk concentrations for each species. Those concentration differences are translated into density differences which are a function of the density of the solvent and of the concentration differences, molecular masses and the standard partial molar volumes of all species. Those density differences in turn can induce convection that will ultimately modify the observed current. However, we did not attempt to quantify details of the natural convection and current modification produced by those density differences.

  13. Dopamine D5 receptor expression is unchanged in peripheral blood lymphocytes in essential hypertension.

    PubMed

    Ricci, A; Chiandussi, L; Schena, M; Schiavone, D; Veglio, F; Amenta, F

    1995-11-01

    The present study was designed to investigate possible changes in the expression of lymphocyte dopamine receptor in essential hypertension. The expression of dopamine D5 receptor was evaluated by radioligand binding techniques using [3H]-SCH 23390 as ligand. Plasma catecholamines, aldosterone levels and plasma renin activity were also measured. Eleven borderline hypertensive patients, 15 patient with the mild essential hypertension, 7 patients with moderate essential hypertension and 5 patients with severe essential hypertension were examined. Plasma catecholamine levels were assayed by high pressure liquid chromatography with electrochemical detection. Dopamine D5 receptor was measured by radioligand binding techniques. Plasma aldosterone levels and renin activity were determined by radio immunoassay. [3H]-SCH 23390 was specifically bound to human peripheral blood lymphocytes. The binding was time-, temperature- and concentration-dependent with a dissociation constant (Kd) value of 0.59 nM and a maximum density of binding sites (Bmax) of 223 pmol/10(6) cells. Dopamine competed with [3H]-SCH 23390 binding in the submicromolar range suggesting the labelling of a dopamine D5 receptor. No changes in the density of [3H]-SCH 23390 binding sites were observed in human peripheral blood lymphocytes between essential hypertensive patients and normotensive subjects. Also catecholamines, plasma renin activity and aldosterone levels were unchanged. In spite of the availability of a sensitive technique for measuring dopamine receptors in human peripheral lymphocytes, no change in their expression was noticeable in essential hypertension. This suggests that dopamine receptor analysis in essential hypertension is not a useful marker for investigating hypertension-dependent changes of the peripheral dopaminergic system.

  14. Negative plant-soil feedbacks increase with plant abundance, and are unchanged by competition.

    PubMed

    Maron, John L; Laney Smith, Alyssa; Ortega, Yvette K; Pearson, Dean E; Callaway, Ragan M

    2016-08-01

    Plant-soil feedbacks and interspecific competition are ubiquitous interactions that strongly influence the performance of plants. Yet few studies have examined whether the strength of these interactions corresponds with the abundance of plant species in the field, or whether feedbacks and competition interact in ways that either ameliorate or exacerbate their effects in isolation. We sampled soil from two intermountain grassland communities where we also measured the relative abundance of plant species. In greenhouse experiments, we quantified the direction and magnitude of plant-soil feedbacks for 10 target species that spanned a range of abundances in the field. In soil from both sites, plant-soil feedbacks were mostly negative, with more abundant species suffering greater negative feedbacks than rare species. In contrast, the average response to competition for each species was unrelated with its abundance in the field. We also determined how competitive response varied among our target species when plants competed in live vs. sterile soil. Interspecific competition reduced plant size, but the strength of this negative effect was unchanged by plant-soil feedbacks. Finally, when plants competed interspecifically, we asked how conspecific-trained, heterospecific-trained, and sterile soil influenced the competitive responses of our target species and how this varied depending on whether target species were abundant or rare in the field. Here, we found that both abundant and rare species were not as harmed by competition when they grew in heterospecific-trained soil compared to when they grew in conspecific-cultured soil. Abundant species were also not as harmed by competition when growing in sterile vs. conspecific-trained soil, but this was not the case for rare species. Our results suggest that abundant plants accrue species-specific soil pathogens to a greater extent than rare species. Thus, negative feedbacks may be critical for preventing abundant species from

  15. Unchanged carbon balance driven by equivalent responses of production and respiration to climate change in a mixed-grass prairie.

    PubMed

    Xu, Xia; Shi, Zheng; Chen, Xuecheng; Lin, Yang; Niu, Shuli; Jiang, Lifen; Luo, Ruiseng; Luo, Yiqi

    2016-05-01

    Responses of grassland carbon (C) cycling to climate change and land use remain a major uncertainty in model prediction of future climate. To explore the impacts of global change on ecosystem C fluxes and the consequent changes in C storage, we have conducted a field experiment with warming (+3 °C), altered precipitation (doubled and halved), and annual clipping at the end of growing seasons in a mixed-grass prairie in Oklahoma, USA, from 2009 to 2013. Results showed that although ecosystem respiration (ER) and gross primary production (GPP) negatively responded to warming, net ecosystem exchange of CO2 (NEE) did not significantly change under warming. Doubled precipitation stimulated and halved precipitation suppressed ER and GPP equivalently, with the net outcome being unchanged in NEE. These results indicate that warming and altered precipitation do not necessarily have profound impacts on ecosystem C storage. In addition, we found that clipping enhanced NEE due to a stronger positive response of GPP compared to ER, indicating that clipping could potentially be an effective land practice that could increase C storage. No significant interactions between warming, altered precipitation, and clipping were observed. Meanwhile, we found that belowground net primary production (BNPP) in general was sensitive to climate change and land use though no significant changes were found in NPP across treatments. Moreover, negative correlations of the ER/GPP ratio with soil temperature and moisture did not differ across treatments, highlighting the roles of abiotic factors in mediating ecosystem C fluxes in this grassland. Importantly, our results suggest that belowground C cycling (e.g., BNPP) could respond to climate change with no alterations in ecosystem C storage in the same period.

  16. Visual acuity in an opportunistic raptor, the chimango caracara (Milvago chimango).

    PubMed

    Potier, Simon; Bonadonna, Francesco; Kelber, Almut; Duriez, Olivier

    2016-04-01

    Raptors are always considered to have an extraordinary resolving power of their eyes (high visual acuity). Nevertheless, raptors differ in their diet and foraging tactics, which could lead to large differences in visual acuity. The visual acuity of an opportunist bird of prey, the Chimango caracara (Mivalgo chimango) was estimated by operant conditioning. Three birds were trained to discriminate two stimuli, a positive grey uniform pattern and a negative grating pattern stimulus. The visual acuity range from 15.08 to 39.83 cycles/degrees. When compared to other birds, they have a higher visual acuity than non-raptorial birds, but they have the lowest visual acuity found in bird of prey so far. We discuss this result in the context of the ecology of the bird, with special focus on it is foraging tactic.

  17. Validation of the Total Visual Acuity Extraction Algorithm (TOVA) for Automated Extraction of Visual Acuity Data From Free Text, Unstructured Clinical Records

    PubMed Central

    Baughman, Douglas M.; Su, Grace L.; Tsui, Irena; Lee, Cecilia S.; Lee, Aaron Y.

    2017-01-01

    Purpose With increasing volumes of electronic health record data, algorithm-driven extraction may aid manual extraction. Visual acuity often is extracted manually in vision research. The total visual acuity extraction algorithm (TOVA) is presented and validated for automated extraction of visual acuity from free text, unstructured clinical notes. Methods Consecutive inpatient ophthalmology notes over an 8-year period from the University of Washington healthcare system in Seattle, WA were used for validation of TOVA. The total visual acuity extraction algorithm applied natural language processing to recognize Snellen visual acuity in free text notes and assign laterality. The best corrected measurement was determined for each eye and converted to logMAR. The algorithm was validated against manual extraction of a subset of notes. Results A total of 6266 clinical records were obtained giving 12,452 data points. In a subset of 644 validated notes, comparison of manually extracted data versus TOVA output showed 95% concordance. Interrater reliability testing gave κ statistics of 0.94 (95% confidence interval [CI], 0.89–0.99), 0.96 (95% CI, 0.94–0.98), 0.95 (95% CI, 0.92–0.98), and 0.94 (95% CI, 0.90–0.98) for acuity numerators, denominators, adjustments, and signs, respectively. Pearson correlation coefficient was 0.983. Linear regression showed an R2 of 0.966 (P < 0.0001). Conclusions The total visual acuity extraction algorithm is a novel tool for extraction of visual acuity from free text, unstructured clinical notes and provides an open source method of data extraction. Translational Relevance Automated visual acuity extraction through natural language processing can be a valuable tool for data extraction from free text ophthalmology notes. PMID:28299240

  18. Visual acuity in ray-finned fishes correlates with eye size and habitat.

    PubMed

    Caves, Eleanor M; Sutton, Tracey T; Johnsen, Sönke

    2017-02-09

    Visual acuity (the ability to resolve spatial detail) is highly variable across fishes. However, little is known about the evolutionary pressures underlying this variation. We reviewed published literature to create an acuity database for 159 species of ray-finned fishes (Actinopterygii). Within a subset of those species for which we had phylogenetic information and anatomically-measured acuity data (n=81), we examined relationships between acuity and both morphological (eye size and body size) and ecological (light level, water turbidity, habitat spatial complexity, and diet) variables. Acuity was significantly correlated with eye size (p<0.05); a weaker correlation with body size occurred via a correlation between eye and body size (p<0.001). Acuity decreased as light level decreased and turbidity increased; however, these decreases resulted from fishes in dark or murky environments having smaller eyes and bodies than those in bright or clear environments. We also found significantly lower acuity in horizon-dominated habitats than in featureless or complex habitats. Higher acuity in featureless habitats is likely due to species having absolutely larger eyes and bodies in that environment, though eye size relative to body size is not significantly different from that in complex environments. Controlling for relative eye size, we found that species in complex environments have even higher acuity than predicted. We found no relationship between visual acuity and diet. Our results show that eye size is a primary factor underlying variation in fish acuity. We additionally show that habitat type is an important ecological factor that correlates with acuity in certain species.

  19. Recovery of visual acuity following the repair of pseudophakic retinal detachment.

    PubMed Central

    Isernhagen, R D; Wilkinson, C P

    1988-01-01

    Postoperative visual acuities were evaluated in a series of 100 pseudophakic eyes in which rhegmatogenous retinal detachments involved the macula and in which reattachment surgery was successful. Preoperative visual acuity and duration of macular detachment were directly and indirectly related to visual outcome, respectively. Eyes in which extracapsular surgery had been followed by posterior chamber lens implantation had significantly better postoperative visual acuities than cases in which older iris-fixation IOLs were placed following intracapsular procedures. PMID:2979019

  20. High and Low Contrast Visual Acuity Are Not Affected in Amyotrophic Lateral Sclerosis.

    PubMed

    Moss, Heather E; Samelson, Monica; Mohan, Girish; Jiang, Qin Li

    2016-01-01

    The afferent visual system may be affected by neuro-degeneration in amyotrophic lateral sclerosis (ALS) based on observations of visual function impairment and retinal inclusions on histopathology in ALS patients. To test the hypothesis that visual acuity is impaired in ALS, we compared three measures of visual acuity in ALS patients (n = 25) attending a multidisciplinary ALS clinic and age matched control subjects (n = 25). Bilateral monocular and binocular visual acuities were assessed using high contrast (black letters on white background) and low contrast (2.5%, 1.25% grey letters on white background) visual acuity charts under controlled lighting conditions following refraction. Binocular summation was calculated as the difference between binocular and best monocular acuity scores. There were no associations between binocular or monocular high contrast visual acuity or low contrast visual acuity and amyotrophic lateral sclerosis diagnosis (generalized estimating equation models accounting for age). Binocular summation was similar in both amyotrophic lateral sclerosis and control subjects. There was a small magnitude association between increased duration of ALS symptoms and reduced 1.25% low contrast visual acuity. This study does not confirm prior observations of impaired visual acuity in patients with amyotrophic lateral sclerosis and does not support this particular measure of visual function for use in broad scale assessment of visual pathway involvement in ALS patients.

  1. High and Low Contrast Visual Acuity Are Not Affected in Amyotrophic Lateral Sclerosis

    PubMed Central

    Samelson, Monica; Mohan, Girish; Jiang, Qin Li

    2016-01-01

    The afferent visual system may be affected by neuro-degeneration in amyotrophic lateral sclerosis (ALS) based on observations of visual function impairment and retinal inclusions on histopathology in ALS patients. To test the hypothesis that visual acuity is impaired in ALS, we compared three measures of visual acuity in ALS patients (n = 25) attending a multidisciplinary ALS clinic and age matched control subjects (n = 25). Bilateral monocular and binocular visual acuities were assessed using high contrast (black letters on white background) and low contrast (2.5%, 1.25% grey letters on white background) visual acuity charts under controlled lighting conditions following refraction. Binocular summation was calculated as the difference between binocular and best monocular acuity scores. There were no associations between binocular or monocular high contrast visual acuity or low contrast visual acuity and amyotrophic lateral sclerosis diagnosis (generalized estimating equation models accounting for age). Binocular summation was similar in both amyotrophic lateral sclerosis and control subjects. There was a small magnitude association between increased duration of ALS symptoms and reduced 1.25% low contrast visual acuity. This study does not confirm prior observations of impaired visual acuity in patients with amyotrophic lateral sclerosis and does not support this particular measure of visual function for use in broad scale assessment of visual pathway involvement in ALS patients. PMID:28033389

  2. Spatial visual acuity of the eagle Aquila audax: a behavioural, optical and anatomical investigation.

    PubMed

    Reymond, L

    1985-01-01

    Behavioural acuity of the wedge-tailed eagle was determined across a range of luminance. Maximum acuity is between 132 and 143 c/deg and with decreasing luminance acuity declines sharply. The maximum anatomical resolving power of the eagle's deep fovea was calculated as 140 c/deg. This calculation was based upon ophthalmoscopic measurement of posterior nodal distance and estimates of photoreceptor spacings made from fixed foveal tissue and corrected for shrinkage. Maximum behavioural acuity and anatomical resolving power correspond closely and approach the highest frequency (157 c/deg) transmitted by the minimum pupil diameter of the eye. These findings are discussed with reference to current theories of visual functioning.

  3. The Relationship between OCT-measured Central Retinal Thickness and Visual Acuity in Diabetic Macular Edema

    PubMed Central

    2008-01-01

    Objective To compare optical coherence tomography (OCT)-measured retinal thickness and visual acuity in eyes with diabetic macular edema (DME) both before and after macular laser photocoagulation. Design Cross-sectional and longitudinal study. Participants 210 subjects (251 eyes) with DME enrolled in a randomized clinical trial of laser techniques. Methods Retinal thickness was measured with OCT and visual acuity was measured with the electronic-ETDRS procedure. Main Outcome Measures OCT-measured center point thickness and visual acuity Results The correlation coefficients for visual acuity versus OCT center point thickness were 0.52 at baseline and 0.49, 0.36, and 0.38 at 3.5, 8, and 12 months post-laser photocoagulation. The slope of the best fit line to the baseline data was approximately 4.4 letters (95% C.I.: 3.5, 5.3) better visual acuity for every 100 microns decrease in center point thickness at baseline with no important difference at follow-up visits. Approximately one-third of the variation in visual acuity could be predicted by a linear regression model that incorporated OCT center point thickness, age, hemoglobin A1C, and severity of fluorescein leakage in the center and inner subfields. The correlation between change in visual acuity and change in OCT center point thickening 3.5 months after laser treatment was 0.44 with no important difference at the other follow-up times. A subset of eyes showed paradoxical improvements in visual acuity with increased center point thickening (7–17% at the three time points) or paradoxical worsening of visual acuity with a decrease in center point thickening (18%–26% at the three time points). Conclusions There is modest correlation between OCT-measured center point thickness and visual acuity, and modest correlation of changes in retinal thickening and visual acuity following focal laser treatment for DME. However, a wide range of visual acuity may be observed for a given degree of retinal edema and paradoxical

  4. [Iliopsoas muscle syndrome. Functional disorders: shortening, spasm and weakness of a structurally unchanged muscle].

    PubMed

    Grgić, Vjekoslav

    2009-01-01

    Functional (non-organic) disorders of the iliopsoas muscle (IPM), i.e. the shortening, spasm and weakness of the structurally unchanged IPM, can be manifested as abdominal and/or pelvic pain, pain in areas of the thoracolumbar (ThL) and lumbosacral (LS) spine, sacroiliac (SI) joint, hip, groin and anterior thigh on the side of the affected muscle as well as gait disturbances (iliopsoas muscle syndrome). By clinical examination of the IPM, including the transabdominal palpation, stretch and strength tests, pathological masses, shortening, painful spasm, weakness and tendon tenderness of that muscle can be diagnosed. The IPM is, like other postural muscles, inclined to shortening. The weakness of the IPM can be a consequence of the lesion of the lumbar plexus or femoral nerve that innervate the IPM, as well as a consequence of certain organic diseases of the IPM. Painful stimuli coming from somatic and visceral structures that are innervated from Th12-L4 nerve roots, from which the IPM segmental innervation also originates, can cause a reflex spasm of the IPM. A painful spasm of the IPM caused by disorders of the ThL and LS spine, SI and hip joint, can mimic diseases of the abdominal and pelvic organs. In the differential diagnosis of the IPM painful spasm, organic diseases of that muscle should be considered foremost (abscess, hematoma, tumor, metastase), as they can result in spasm, and the diseases of the abdominal and pelvic organs that can cause an IPM reflex spasm. The IPM functional disorders, which are not rare, are often overlooked during a clinical examination of a patient. Reasons for overlooking these disorders are: 1) a nonspecific and variable clinical picture presenting the IPM functional disorders, 2) the IPM functional disorders are a neglected source of pain, 3) the inaccessibility of the IPM for inspection, 4) the lack of knowledge of the IPM examination techniques and 5) the IPM functional disorders cannot be discovered by radiological

  5. Parasite remains in archaeological sites.

    PubMed

    Bouchet, Françoise; Guidon, Niéde; Dittmar, Katharina; Harter, Stephanie; Ferreira, Luiz Fernando; Chaves, Sergio Miranda; Reinhard, Karl; Araújo, Adauto

    2003-01-01

    Organic remains can be found in many different environments. They are the most significant source for paleoparasitological studies as well as for other paleoecological reconstruction. Preserved paleoparasitological remains are found from the driest to the moistest conditions. They help us to understand past and present diseases and therefore contribute to understanding the evolution of present human sociality, biology, and behavior. In this paper, the scope of the surviving evidence will be briefy surveyed, and the great variety of ways it has been preserved in different environments will be discussed. This is done to develop to the most appropriated techniques to recover remaining parasites. Different techniques applied to the study of paleoparasitological remains, preserved in different environments, are presented. The most common materials used to analyze prehistoric human groups are reviewed, and their potential for reconstructing ancient environment and disease are emphasized. This paper also urges increased cooperation among archaeologists, paleontologists, and paleoparasitologists.

  6. Proximal versus distal cue utilization in spatial navigation: the role of visual acuity?

    PubMed

    Carman, Heidi M; Mactutus, Charles F

    2002-09-01

    Proximal versus distal cue use in the Morris water maze is a widely accepted strategy for the dissociation of various problems affecting spatial navigation in rats such as aging, head trauma, lesions, and pharmacological or hormonal agents. Of the limited number of ontogenetic rat studies conducted, the majority have approached the problem of preweanling spatial navigation through a similar proximal-distal dissociation. An implicit assumption among all of these studies has been that the animal's visual system is sufficient to permit robust spatial navigation. We challenged this assumption and have addressed the role of visual acuity in spatial navigation in the preweanling Fischer 344-N rat by training animals to locate a visible (proximal) or hidden (distal) platform using double or null extramaze cues within the testing environment. All pups demonstrated improved performance across training, but animals presented with a visible platform, regardless of extramaze cues, simultaneously reached asymptotic performance levels; animals presented with a hidden platform, dependent upon location of extramaze cues, differentially reached asymptotic performance levels. Probe trial performance, defined by quadrant time and platform crossings, revealed that distal-double-cue pups demonstrated spatial navigational ability superior to that of the remaining groups. These results suggest that a pup's ability to spatially navigate a hidden platform is dependent on not only its response repertoire and task parameters, but also its visual acuity, as determined by the extramaze cue location within the testing environment. The standard hidden versus visible platform dissociation may not be a satisfactory strategy for the control of potential sensory deficits.

  7. Sensitivity of The Dynamic Visual Acuity Test To Sensorimotor Change

    NASA Technical Reports Server (NTRS)

    Cohen, Helen; Bloomberg, Jacob; Elizalde, Elizabeth; Fregia, Melody

    1999-01-01

    Post-flight astronauts, acutely post-vestibular nerve section patients, and patients with severe chronic bilateral vestibular deficits have oscillopsia caused by reduced vestibulocular reflex gains and decreased postural stability. Therefore, as previous work has shown, a test of dynamic visual acuity (DVA), in which the subject must read numbers from a computer screen while standing still or walking in place provides a composite measure of sensorimotor integration. This measure may be useful for determining the level of recovery, post-flight, post-operatively, or after vestibular rehabilitation. To determine the sensitivity of DVA to change in impaired populations we have tested patients with acoustic neuromas before and during the first post-operative week after resection of the tumors, and with bilaterally labyrinthine deficient subjects before and after six weeks of balance rehabilitation therapy.

  8. Recovery of stereo acuity in adults with amblyopia

    PubMed Central

    Astle, Andrew T; McGraw, Paul V; Webb, Ben S

    2011-01-01

    Disruption of visual input to one eye during early development leads to marked functional impairments of vision, commonly referred to as amblyopia. A major consequence of amblyopia is the inability to encode binocular disparity information leading to impaired depth perception or stereo acuity. If amblyopia is treated early in life (before 4 years of age), then recovery of normal stereoscopic function is possible. Treatment is rarely undertaken later in life (adulthood) because declining levels of neural plasticity are thought to limit the effectiveness of standard treatments. Here, the authors show that a learning-based therapy, designed to exploit experience-dependent plastic mechanisms, can be used to recover stereoscopic visual function in adults with amblyopia. These cases challenge the long-held dogma that the critical period for visual development and the window for treating amblyopia are one and the same. PMID:22707543

  9. Collective enhancement of numerical acuity by meritocratic leadership in fish.

    PubMed

    Bisazza, Angelo; Butterworth, Brian; Piffer, Laura; Bahrami, Bahador; Miletto Petrazzini, Maria Elena; Agrillo, Christian

    2014-04-02

    It has been known for more than a century that interacting people can generally achieve more accurate decisions than single individuals. Here we show that interacting guppy fish (Poecilia reticulata) achieve a superior level of numerosity discrimination well beyond the average ability of the isolated individual fish. This enhancement of numerical acuity was observed in dyadic interactions when (Experiment 1) the dyad chose which larger shoal of guppies to join and when (Experiment 2) the dyad chose the higher or the lower numerosity among two decision options after having learned the task individually. Dyadic accuracy and that of the more competent member of each dyad matched closely, supporting the hypothesis that meritocratic leadership arises spontaneously between dyadically interacting fish, rather than the 'many wrongs' principle that has been used to explain group superiority in many species.

  10. Photovoltaic restoration of sight with high visual acuity.

    PubMed

    Lorach, Henri; Goetz, Georges; Smith, Richard; Lei, Xin; Mandel, Yossi; Kamins, Theodore; Mathieson, Keith; Huie, Philip; Harris, James; Sher, Alexander; Palanker, Daniel

    2015-05-01

    Patients with retinal degeneration lose sight due to the gradual demise of photoreceptors. Electrical stimulation of surviving retinal neurons provides an alternative route for the delivery of visual information. We demonstrate that subretinal implants with 70-μm-wide photovoltaic pixels provide highly localized stimulation of retinal neurons in rats. The electrical receptive fields recorded in retinal ganglion cells were similar in size to the natural visual receptive fields. Similarly to normal vision, the retinal response to prosthetic stimulation exhibited flicker fusion at high frequencies, adaptation to static images and nonlinear spatial summation. In rats with retinal degeneration, these photovoltaic arrays elicited retinal responses with a spatial resolution of 64 ± 11 μm, corresponding to half of the normal visual acuity in healthy rats. The ease of implantation of these wireless and modular arrays, combined with their high resolution, opens the door to the functional restoration of sight in patients blinded by retinal degeneration.

  11. Photovoltaic restoration of sight with high visual acuity

    PubMed Central

    Lorach, Henri; Goetz, Georges; Smith, Richard; Lei, Xin; Mandel, Yossi; Kamins, Theodore; Mathieson, Keith; Huie, Philip; Harris, James; Sher, Alexander; Palanker, Daniel

    2015-01-01

    Patients with retinal degeneration lose sight due to gradual demise of photoreceptors. Electrical stimulation of the surviving retinal neurons provides an alternative route for delivery of visual information. We demonstrate that subretinal arrays with 70 μm photovoltaic pixels provide highly localized stimulation, with electrical and visual receptive fields of comparable sizes in rat retinal ganglion cells. Similarly to normal vision, retinal response to prosthetic stimulation exhibits flicker fusion at high frequencies, adaptation to static images and non-linear spatial summation. In rats with retinal degeneration, these photovoltaic arrays provide spatial resolution of 64 ± 11 μm, corresponding to half of the normal visual acuity in pigmented rats. Ease of implantation of these wireless and modular arrays, combined with their high resolution opens the door to functional restoration of sight. PMID:25915832

  12. A comparison of vernier acuity for narrowband and broadband stimuli.

    PubMed

    Barrett, Brendan T; Whitaker, David

    2004-01-01

    This study investigates the influence of contrast and exposure duration on vernier acuity thresholds for abutting and separated narrowband stimuli, and asks whether these data can predict broadband vernier performance. Vernier thresholds were determined for sinusoidal grating stimuli at two spatial frequencies (1 and 8 c/deg) across a range of contrasts (0.05-0.8) and exposure durations (35-2100 ms). Performance was assessed for the abutting configuration, and when a gap equivalent to 0.5 to 1.5 times the spatial period of the grating was introduced between the upper and lower halves of the grating. Vernier thresholds were also determined for a square-wave stimulus as a function of contrast (0.06 to 0.78). Exposure duration was fixed at 2100 ms. In addition, thresholds were determined at the appropriate contrast levels for the fundamental frequency (1.8 c/deg) of the square-wave, and for a number of the harmonics (3F, 5F, 7F, 9F). Our results provide support for filter models of vernier acuity by showing that vernier performance for abutting and closely-separated broadband stimuli represents the envelope of vernier sensitivity of those spatial frequency mechanisms that are activated by the broadband stimulus. In the case of high frequency grating stimuli presented for long exposure durations, vernier performance can be invariant across much of the contrast range. Despite this, however, contrast independence is not exhibited for abutting broadband stimuli because, within the broadband stimuli, the contrast of the higher harmonic components never reaches a level to reveal this plateau.

  13. Amblyopia and visual acuity in children with Down's syndrome

    PubMed Central

    Tsiaras, W.; Pueschel, S.; Keller, C.; Curran, R.; Giesswein, S.

    1999-01-01

    BACKGROUND/AIMS—Amblyopia in people with Down's syndrome has not been well investigated. This study was designed to determine the prevalence and associated conditions of amblyopia in a group of home reared children with Down's syndrome.
METHODS—All children in the study group underwent an evaluation of visual acuity. In addition, previous ophthalmological records were reviewed, and a subgroup of children was examined. For the purposes of this study, amblyopia was defined quantitatively as a difference of two Snellen acuity lines between eyes or if unilateral central steady maintained (CSM) vision and a clear fixation preference was observed. A high refractive error was defined as a spherical equivalent more than 3 dioptres and astigmatism more than 1.75 dioptres. Anisometropia was defined as a difference of at least 1.5 dioptres of sphere and/or 1.0 dioptre of cylinder between eyes. 68 children with Down's syndrome between the ages of 5 and 19 years were enrolled in the final study group.
RESULTS—Amblyopia was observed in 15 (22%) of 68 patients. An additional 16 (24%) patients had bilateral vision less than 20/50. Strabismus, high refractive errors, and anisometropia were the conditions most commonly associated with decreased vision and amblyopia
CONCLUSION—This study suggests that the prevalence of amblyopia is higher than previously reported. Fully 46% of these children with Down's syndrome had evidence of substantial visual deficits. These patients may be at higher risk for visual impairment and should be carefully examined for ophthalmological problems.

 PMID:10502568

  14. Content and Access Remain Key

    ERIC Educational Resources Information Center

    Johnson, Linda B.

    2007-01-01

    It is impossible to review the year's outstanding government publication landscape without acknowledging that change remains paramount. Just as striking, however, is that these changes go hand in hand with some familiar constants. Within this shifting environment, there are the consistency and dependability of government information itself,…

  15. Unchanged Levels of Soluble CD14 and IL-6 Over Time Predict Serious Non-AIDS Events in HIV-1-Infected People.

    PubMed

    Sunil, Meena; Nigalye, Maitreyee; Somasunderam, Anoma; Martinez, Maria Laura; Yu, Xiaoying; Arduino, Roberto C; Utay, Netanya S; Bell, Tanvir K

    2016-12-01

    HIV-1-infected persons have increased risk of serious non-AIDS events (SNAEs) despite suppressive antiretroviral therapy. Increased circulating levels of soluble CD14 (sCD14), soluble CD163 (sCD163), and interleukin-6 (IL-6) at a single time point have been associated with SNAEs. However, whether changes in these biomarker levels predict SNAEs in HIV-1-infected persons is unknown. We hypothesized that greater decreases in inflammatory biomarkers would be associated with fewer SNAEs. We identified 39 patients with SNAEs, including major cardiovascular events, end stage renal disease, decompensated cirrhosis, non-AIDS-defining malignancies, and death of unknown cause, and age- and sex-matched HIV-1-infected controls. sCD14, sCD163, and IL-6 were measured at study enrollment (T1) and proximal to the event (T2) or equivalent duration in matched controls. Over ∼34 months, unchanged rather than decreasing levels of sCD14 and IL-6 predicted SNAEs. Older age and current illicit substance abuse, but not HCV coinfection, were associated with SNAEs. In a multivariate analysis, older age, illicit substance use, and unchanged IL-6 levels remained significantly associated with SNAEs. Thus, the trajectories of sCD14 and IL-6 levels predict SNAEs. Interventions to decrease illicit substance use may decrease the risk of SNAEs in HIV-1-infected persons.

  16. Vernier Acuity and the Magnocellular System Revisited: Response to Skottun and Skoyles

    ERIC Educational Resources Information Center

    Keri, Szabolcs; Benedek, Gyorgy

    2010-01-01

    Skottun and Skoyles (2009) recently presented a comment on Vernier acuity and magnocellular dysfunctions in fragile X premutation carriers (Keri & Benedek, 2009). The authors concluded that our finding that the magnocellular deficit, as revealed by luminance-contrast sensitivity measurements, is associated with impaired Vernier acuity for…

  17. Age Differences in the Relationship between Visual Movement Imagery and Performance on Kinesthetic Acuity Tests.

    ERIC Educational Resources Information Center

    Livesey, David J.

    2002-01-01

    Investigated the relationship between Vividness of Movement Imagery Questionnaire scores and kinesthetic acuity--the sense of body position and movement--among 10- and 14-year-olds. Found that in the older group, those with high levels of visual movement imagery performed better on measures of kinesthetic acuity; no such effect was found for…

  18. Visual Acuity of Radiologists: The Important but Forgotten Component of the Radiological Process.

    ERIC Educational Resources Information Center

    Good, Barbara C.

    This paper reports on a study of visual acuity among radiologists. Twenty-eight radiologists had their visual acuity tested by an optometrist. One week later, 70 medical school faculty radiologists were asked to respond to a printed questionnaire that elicited information about: (1) the date of the respondent's immediately previous examination;…

  19. Comparison of Dynamic Visual Acuity between Water Polo Players and Sedentary Students

    ERIC Educational Resources Information Center

    Quevedo-Junyent, Lluisa; Aznar-Casanova, Jose Antonio; Merindano-Encina, Dolores; Cardona, Genis; Sole-Forto, Joan

    2011-01-01

    In this study, we examined differences in dynamic visual acuity between elite and subelite water polo players and sedentary students. To measure dynamic visual acuity binocularly, we asked participants to indicate the orientation of a broken ring, similar to the Landolt C, which increased in size as it moved across a computer screen. Two different…

  20. Burn Patient Acuity Demographics, Scar Contractures and Rehabilitation Treatment Time Related to Patient Outcomes (ACT)

    DTIC Science & Technology

    2011-10-01

    Patient Acuity Demographics, Scar Contractures and Rehabilitation Treatment Time Related to Patient Outcomes (ACT) Mr. Reginald Richard American Burn...and Rehabilitation Treatment Time Related to Patient Outcomes, conveniently referred to as the ACT representing Acuity, Contractures and Time, is...wound leading to scar contracture begins almost immediately after the burning process stops. Rehabilitation treatment delivered prior to beginning

  1. 49 CFR 240.121 - Criteria for vision and hearing acuity data.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Criteria for vision and hearing acuity data. 240... ENGINEERS Component Elements of the Certification Process § 240.121 Criteria for vision and hearing acuity... paragraph (e) of this section, a person's vision and hearing shall meet or exceed the standards...

  2. 49 CFR 240.121 - Criteria for vision and hearing acuity data.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Criteria for vision and hearing acuity data. 240... ENGINEERS Component Elements of the Certification Process § 240.121 Criteria for vision and hearing acuity... paragraph (e) of this section, a person's vision and hearing shall meet or exceed the standards...

  3. 49 CFR 240.121 - Criteria for vision and hearing acuity data.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Criteria for vision and hearing acuity data. 240... ENGINEERS Component Elements of the Certification Process § 240.121 Criteria for vision and hearing acuity... paragraph (e) of this section, a person's vision and hearing shall meet or exceed the standards...

  4. 49 CFR 240.207 - Procedures for making the determination on vision and hearing acuity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Procedures for making the determination on vision and hearing acuity. 240.207 Section 240.207 Transportation Other Regulations Relating to... making the determination on vision and hearing acuity. (a) Each railroad, prior to initially...

  5. 49 CFR 240.121 - Criteria for vision and hearing acuity data.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Criteria for vision and hearing acuity data. 240... ENGINEERS Component Elements of the Certification Process § 240.121 Criteria for vision and hearing acuity... paragraph (e) of this section, a person's vision and hearing shall meet or exceed the standards...

  6. 49 CFR 240.207 - Procedures for making the determination on vision and hearing acuity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Procedures for making the determination on vision and hearing acuity. 240.207 Section 240.207 Transportation Other Regulations Relating to... making the determination on vision and hearing acuity. (a) Each railroad, prior to initially...

  7. 49 CFR 240.207 - Procedures for making the determination on vision and hearing acuity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Procedures for making the determination on vision and hearing acuity. 240.207 Section 240.207 Transportation Other Regulations Relating to... making the determination on vision and hearing acuity. (a) Each railroad, prior to initially...

  8. 49 CFR 240.121 - Criteria for vision and hearing acuity data.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Criteria for vision and hearing acuity data. 240... ENGINEERS Component Elements of the Certification Process § 240.121 Criteria for vision and hearing acuity... paragraph (e) of this section, a person's vision and hearing shall meet or exceed the standards...

  9. 49 CFR 240.207 - Procedures for making the determination on vision and hearing acuity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Procedures for making the determination on vision and hearing acuity. 240.207 Section 240.207 Transportation Other Regulations Relating to... making the determination on vision and hearing acuity. (a) Each railroad, prior to initially...

  10. 49 CFR 240.207 - Procedures for making the determination on vision and hearing acuity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Procedures for making the determination on vision and hearing acuity. 240.207 Section 240.207 Transportation Other Regulations Relating to... making the determination on vision and hearing acuity. (a) Each railroad, prior to initially...

  11. Acuity of the Approximate Number System and Preschoolers' Quantitative Development

    ERIC Educational Resources Information Center

    van Marle, Kristy; Chu, Felicia W.; Li, Yaoran; Geary, David C.

    2014-01-01

    The study assessed the relations among acuity of the inherent approximate number system (ANS), performance on measures of symbolic quantitative knowledge, and mathematics achievement for a sample of 138 (64 boys) preschoolers. The Weber fraction (a measure of ANS acuity) and associated task accuracy were significantly correlated with mathematics…

  12. Night vision in barn owls: visual acuity and contrast sensitivity under dark adaptation.

    PubMed

    Orlowski, Julius; Harmening, Wolf; Wagner, Hermann

    2012-12-06

    Barn owls are effective nocturnal predators. We tested their visual performance at low light levels and determined visual acuity and contrast sensitivity of three barn owls by their behavior at stimulus luminances ranging from photopic to fully scotopic levels (23.5 to 1.5 × 10⁻⁶). Contrast sensitivity and visual acuity decreased only slightly from photopic to scotopic conditions. Peak grating acuity was at mesopic (4 × 10⁻² cd/m²) conditions. Barn owls retained a quarter of their maximal acuity when luminance decreased by 5.5 log units. We argue that the visual system of barn owls is designed to yield as much visual acuity under low light conditions as possible, thereby sacrificing resolution at photopic conditions.

  13. The Eye Phone Study: reliability and accuracy of assessing Snellen visual acuity using smartphone technology

    PubMed Central

    Perera, C; Chakrabarti, R; Islam, F M A; Crowston, J

    2015-01-01

    Purpose Smartphone-based Snellen visual acuity charts has become popularized; however, their accuracy has not been established. This study aimed to evaluate the equivalence of a smartphone-based visual acuity chart with a standard 6-m Snellen visual acuity (6SVA) chart. Methods First, a review of available Snellen chart applications on iPhone was performed to determine the most accurate application based on optotype size. Subsequently, a prospective comparative study was performed by measuring conventional 6SVA and then iPhone visual acuity using the ‘Snellen' application on an Apple iPhone 4. Results Eleven applications were identified, with accuracy of optotype size ranging from 4.4–39.9%. Eighty-eight patients from general medical and surgical wards in a tertiary hospital took part in the second part of the study. The mean difference in logMAR visual acuity between the two charts was 0.02 logMAR (95% limit of agreement −0.332, 0.372 logMAR). The largest mean difference in logMAR acuity was noted in the subgroup of patients with 6SVA worse than 6/18 (n=5), who had a mean difference of two Snellen visual acuity lines between the charts (0.276 logMAR). Conclusion We did not identify a Snellen visual acuity app at the time of study, which could predict a patients standard Snellen visual acuity within one line. There was considerable variability in the optotype accuracy of apps. Further validation is required for assessment of acuity in patients with severe vision impairment. PMID:25931170

  14. Malingering or simulation in ophthalmology-visual acuity

    PubMed Central

    Incesu, Ali Ihsan; Sobacı, Güngör

    2011-01-01

    Simulation can be defined as malingering, or sometimes functional visual loss (FVL). It manifests as either simulating an ophthalmic disease (positive simulation), or denial of ophthalmic disease (negative simulation). Conscious behavior and compensation or indemnity claims are prominent features of simulation. Since some authors suggest that this is a manifestation of underlying psychopathology, even conversion is included in this context. In today's world, every ophthalmologist can face with simulation of ophthalmic disease or disorder. In case of simulation suspect, the physician's responsibility is to prove the simulation considering the disease/disorder first, and simulation as an exclusion. In simulation examinations, the physician should be firm and smart to select appropriate test(s) to convince not only the subject, but also the judge in case of indemnity or compensation trials. Almost all ophthalmic sensory and motor functions including visual acuity, visual field, color vision and night vision can be the subject of simulation. Examiner must be skillful in selecting the most appropriate test. Apart from those in the literature, we included all kinds of simulation in ophthalmology. In addition, simulation examination techniques, such as, use of OCT (optical coherence tomography), frequency doubling perimetry (FDP), and modified polarization tests were also included. In this review, we made a thorough literature search, and added our experiences to give the readers up-to-date information on malingering or simulation in ophthalmology. PMID:22553721

  15. Objective evaluation of the visual acuity in human eyes

    NASA Astrophysics Data System (ADS)

    Rosales, M. A.; López-Olazagasti, E.; Ramírez-Zavaleta, G.; Varillas, G.; Tepichín, E.

    2009-08-01

    Traditionally, the quality of the human vision is evaluated by a subjective test in which the examiner asks the patient to read a series of characters of different sizes, located at a certain distance of the patient. Typically, we need to ensure a subtended angle of vision of 5 minutes, which implies an object of 8.8 mm high located at 6 meters (normal or 20/20 visual acuity). These characters constitute what is known as the Snellen chart, universally used to evaluate the spatial resolution of the human eyes. The mentioned process of identification of characters is carried out by means of the eye - brain system, giving an evaluation of the subjective visual performance. In this work we consider the eye as an isolated image-forming system, and show that it is possible to isolate the function of the eye from that of the brain in this process. By knowing the impulse response of the eye´s system we can obtain, in advance, the image of the Snellen chart simultaneously. From this information, we obtain the objective performance of the eye as the optical system under test. This type of results might help to detect anomalous situations of the human vision, like the so called "cerebral myopia".

  16. Insects groom their antennae to enhance olfactory acuity

    PubMed Central

    Böröczky, Katalin; Wada-Katsumata, Ayako; Batchelor, Dale; Zhukovskaya, Marianna; Schal, Coby

    2013-01-01

    Grooming, a common behavior in animals, serves the important function of removing foreign materials from body surfaces. When antennal grooming was prevented in the American cockroach, Periplaneta americana, field emission gun scanning electron microscopy images revealed that an unstructured substance accumulated on nongroomed antennae, covering sensillar pores, but not on groomed antennae of the same individuals. Gas chromatography analysis of antennal extracts showed that over a 24-h period nongroomed antennae accumulated three to four times more cuticular hydrocarbons than groomed antennae. Moreover, nongroomed antennae accumulated significantly more environmental contaminants from surfaces (stearic acid) and from air (geranyl acetate) than groomed antennae. We hypothesized that the accumulation of excess native cuticular hydrocarbons on the antennae would impair olfactory reception. Electroantennogram experiments and single-sensillum recordings supported this hypothesis: antennae that were prevented from being groomed were significantly less responsive than groomed antennae to the sex pheromone component periplanone-B, as well as to the general odorants geranyl acetate and hexanol. We therefore conclude that antennal grooming removes excess native cuticular lipids and foreign chemicals that physically and/or chemically interfere with olfaction, and thus maintains the olfactory acuity of the antennae. Similar experimental manipulations of the German cockroach (Blattella germanica), carpenter ant (Camponotus pennsylvanicus), and the housefly (Musca domestica), which use different modes of antennal grooming, support the hypothesis that antennal grooming serves a similar function in a wide range of insect taxa. PMID:23382193

  17. Face context advantage explained by vernier and separation discrimination acuity.

    PubMed

    Vesker, Michael; Wilson, Hugh R

    2012-01-01

    Seeing facial features in the context of a full face is known to provide an advantage for perception. Using an interocular separation perception task we confirmed that seeing eyes within the context of a face improves discrimination in synthetic faces. We also show that this improvement of the face context can be explained using the presence of individual components of the face such as the nose mouth, or head-outline. We demonstrate that improvements due to the presence of the nose, and head-outline can be explained in terms of two-point separation measurements, obeying Weber's law as established in the literature. We also demonstrate that performance improvements due to the presence of the mouth can be explained in terms of Vernier acuity judgments between eye positions and the corners of the mouth. Overall, our study shows that the improvements in perception of facial features due to the face context effect can be traced to well understood basic visual measurements that may play a very general role in perceptual measurements of distance. Deficiencies in these measurements may also play a role in prosopagnosia. Additionally, we show interference of the eyebrows with the face-inversion effect for interocular discrimination.

  18. Believing is seeing: using mindlessness (mindfully) to improve visual acuity.

    PubMed

    Langer, Ellen; Djikic, Maja; Pirson, Michael; Madenci, Arin; Donohue, Rebecca

    2010-05-01

    These experiments show that vision can be improved by manipulating mind-sets. In Study 1, participants were primed with the mind-set that pilots have excellent vision. Vision improved for participants who experientially became pilots (by flying a realistic flight simulator) compared with control participants (who performed the same task in an ostensibly broken flight simulator). Participants in an eye-exercise condition (primed with the mind-set that improvement occurs with practice) and a motivation condition (primed with the mind-set "try and you will succeed") demonstrated visual improvement relative to the control group. In Study 2, participants were primed with the mind-set that athletes have better vision than nonathletes. Controlling for arousal, doing jumping jacks resulted in greater visual acuity than skipping (perceived to be a less athletic activity than jumping jacks). Study 3 took advantage of the mind-set primed by the traditional eye chart: Because letters get progressively smaller on successive lines, people expect that they will be able to read the first few lines only. When participants viewed a reversed chart and a shifted chart, they were able to see letters they could not see before. Thus, mind-set manipulation can counteract physiological limits imposed on vision.

  19. Cognitive aging and hearing acuity: modeling spoken language comprehension

    PubMed Central

    Wingfield, Arthur; Amichetti, Nicole M.; Lash, Amanda

    2015-01-01

    The comprehension of spoken language has been characterized by a number of “local” theories that have focused on specific aspects of the task: models of word recognition, models of selective attention, accounts of thematic role assignment at the sentence level, and so forth. The ease of language understanding (ELU) model (Rönnberg et al., 2013) stands as one of the few attempts to offer a fully encompassing framework for language understanding. In this paper we discuss interactions between perceptual, linguistic, and cognitive factors in spoken language understanding. Central to our presentation is an examination of aspects of the ELU model that apply especially to spoken language comprehension in adult aging, where speed of processing, working memory capacity, and hearing acuity are often compromised. We discuss, in relation to the ELU model, conceptions of working memory and its capacity limitations, the use of linguistic context to aid in speech recognition and the importance of inhibitory control, and language comprehension at the sentence level. Throughout this paper we offer a constructive look at the ELU model; where it is strong and where there are gaps to be filled. PMID:26124724

  20. The relationship between visual acuity and functioning and well-being among diabetics.

    PubMed

    Lee, P P; Whitcup, S M; Hays, R D; Spritzer, K; Javitt, J

    1995-08-01

    Given the enormous recent interest in functional capabilities related to vision, the goal of this study was to examine the relationship of standard clinical measures of vision (e.g. Snellen acuity) to functioning and well-being. The association between Snellen visual acuity, Amsler grid distortion and presence of diabetic retinopathy with self-reported functioning and well-being (SF-36) were examined in a sample of 327 diabetics from the Medical Outcomes Study (MOS). There was little or no correlation between Snellen visual acuity, Amsler grid distortion or diabetic retinopathy and functioning and well-being (i.e. SF-36 scales). Maximum product-moment correlation was 0.15 with worst eye visual acuity, 0.13 with best eye visual acuity, 0.08 with presence of retinopathy, and 0.10 with Amsler grid distortion. Analysis of variance revealed that visual acuity (both best and worst eye) was statistically related only to the physical function scale; no other exam measure was related to any other SF-36 scale score. Snellen visual acuity, Amsler distortion and diabetic retinopathy correlate weakly with patient self-reported functioning and well-being. Thus, the information provided by functioning and well-being measures is complementary to that of standard clinical measures of visual ability.

  1. Visual acuity and quality of life in dry eye disease: Proceedings of the OCEAN group meeting.

    PubMed

    Benítez-Del-Castillo, José; Labetoulle, Marc; Baudouin, Christophe; Rolando, Maurizio; Akova, Yonca A; Aragona, Pasquale; Geerling, Gerd; Merayo-Lloves, Jesús; Messmer, Elisabeth M; Boboridis, Kostas

    2017-04-01

    Dry eye disease (DED) results in tear film instability and hyperosmolarity, inflammation of the ocular surface and, ultimately, visual disturbance that can significantly impact a patient's quality of life. The effects on visual acuity result in difficulties with driving, reading and computer use and negatively impact psychological health. These effects also extend to the workplace, with a loss of productivity and quality of work causing substantial economic losses. The effects of DED and the impact on vision experienced by patients may not be given sufficient importance by ophthalmologists. Functional visual acuity (FVA) is a measure of visual acuity after sustained eye opening without blinking for at least 10 s and mimics the sustained visual acuity of daily life. Measuring dynamic FVA allows the detection of impaired visual function in patients with DED who may display normal conventional visual acuity. There are currently several tests and methods that can be used to measure dynamic visual function: the SSC-350 FVA measurement system, assessment of best-corrected visual acuity decay using the interblink visual acuity decay test, serial measurements of ocular and corneal higher order aberrations, and measurement of dynamic vision quality using the Optical Quality Analysis System. Although the equipment for these methods may be too large or unaffordable for use in clinical practice, FVA testing is an important assessment for DED.

  2. ANS acuity and mathematics ability in preschoolers from low-income homes: contributions of inhibitory control.

    PubMed

    Fuhs, Mary Wagner; McNeil, Nicole M

    2013-01-01

    Recent findings by Libertus, Feigenson, and Halberda (2011) suggest that there is an association between the acuity of young children's approximate number system (ANS) and their mathematics ability before exposure to instruction in formal schooling. The present study examined the generalizability and validity of these findings in a sample of preschoolers from low-income homes. Children attending Head Start (N = 103) completed measures to assess ANS acuity, mathematics ability, receptive vocabulary, and inhibitory control. Results showed only a weak association between ANS acuity and mathematics ability that was reduced to non-significance when controlling for a direct measure of receptive vocabulary. Results also revealed that inhibitory control plays an important role in the relation between ANS acuity and mathematics ability. Specifically, ANS acuity accounted for significant variance in mathematics ability over and above receptive vocabulary, but only for ANS acuity trials in which surface area conflicted with numerosity. Moreover, this association became non-significant when controlling for inhibitory control. These results suggest that early mathematical experiences prior to formal schooling may influence the strength of the association between ANS acuity and mathematics ability and that inhibitory control may drive that association in young children.

  3. Neural correlate of vernier acuity tasks assessed by functional MRI (FMRI).

    PubMed

    Sheth, Kevin N; Walker, B Michael; Modestino, Edward J; Miki, Atsushi; Terhune, Kyla P; Francis, Ellie L; Haselgrove, John C; Liu, Grant T

    2007-01-01

    Vernier acuity refers to the ability to discern a small offset within a line. However, while Vernier acuity has been extensively studied psychophysically, its neural correlates are uncertain. Based upon previous psychophysical and electrophysiologic data, we hypothesized that extrastriate areas of the brain would be involved in Vernier acuity tasks, so we designed event-related functional MRI (fMRI) paradigms to identify cortical regions of the brain involved in this behavior. Normal subjects identified suprathreshold and subthreshold Vernier offsets. The results suggest a cortical network including frontal, parietal, occipital, and cerebellar regions subserves the observation, processing, interpretation, and acknowledgment of briefly presented Vernier offsets.

  4. Visual acuity loss and OCT changes as initial signs of leukaemia

    PubMed Central

    Ortiz, Jose M; Ruiz-Moreno, Jose M; Pozo-Martos, Paola; Montero, Javier A

    2010-01-01

    AIM To report two cases where decreased visual acuity was the first symptom of leukaemia and optical coherence tomography (OCT) allowed identification and localization of the retinal lesions. METHODS Retrospective, interventional, case reports. RESULTS One case of lymphoblastic acute leukaemia and chronic lymphoid leukaemia were diagnosed following decreased visual acuity. OCT showed macular serous detachment in the first case. The second case presented hypo fluorescent retinal infiltrates which appeared as hyper reflective lesions by OCT. Retinal changes disappeared and visual acuity was recovered following complete remission of the neoplasm. CONCLUSION OCT is a valuable, non invasive diagnostic tool permitting detection, localization and follow-up of ocular dissemination of neoplasms. PMID:22553573

  5. Tactile roughness discrimination threshold is unrelated to tactile spatial acuity.

    PubMed

    Libouton, Xavier; Barbier, Olivier; Plaghki, Leon; Thonnard, Jean-Louis

    2010-04-02

    The present study examined the relationship between the tactile roughness discrimination threshold (TRDT) and the tactile spatial resolution threshold (TSRT) at the index fingertip in humans. A new device was built for measuring TRDT, allowing pair-wise presentations of two sets of six different sandpaper grits. The smoothest grits ranged from 18 to 40 microm and the roughest grits ranged from 50 to 195 microm particle size. The reference sandpaper had a 46 microm particle size. A two-alternative forced choice paradigm and a double interlaced adaptive staircase procedure yielding a 75% just noticeable difference (75%jnd) was used according to Zwislocki and Relkin. Contact force and scanning velocity were measured at the fingertip with a built-in sensor. The TSRT was assessed with an extended set of grating domes. Fifty-three male and female subjects, spanning a wide age range participated in this study. The JND75% or TRDT was lower for the smoothest sandpapers (15+/-8.5 microm) compared to the roughest sandpapers (44+/-32.5 microm). TRDT performance was unrelated to age or gender. Additionally, grit size had no effect on the mean forces (normal and tangential) exerted at the fingertip or the mean scan velocities. In contrast, there was a significant degradation of TSRT performance with age. Lastly, there was no significant correlation between TRDT and TRST performance. Results of this study support the theory that the neural mechanisms underlying the perception of tactile roughness discrimination for fine textures differ from those involved in spatial resolution acuity often associated with the SA1 afferents.

  6. Silicon photonics: some remaining challenges

    NASA Astrophysics Data System (ADS)

    Reed, G. T.; Topley, R.; Khokhar, A. Z.; Thompson, D. J.; Stanković, S.; Reynolds, S.; Chen, X.; Soper, N.; Mitchell, C. J.; Hu, Y.; Shen, L.; Martinez-Jimenez, G.; Healy, N.; Mailis, S.; Peacock, A. C.; Nedeljkovic, M.; Gardes, F. Y.; Soler Penades, J.; Alonso-Ramos, C.; Ortega-Monux, A.; Wanguemert-Perez, G.; Molina-Fernandez, I.; Cheben, P.; Mashanovich, G. Z.

    2016-03-01

    This paper discusses some of the remaining challenges for silicon photonics, and how we at Southampton University have approached some of them. Despite phenomenal advances in the field of Silicon Photonics, there are a number of areas that still require development. For short to medium reach applications, there is a need to improve the power consumption of photonic circuits such that inter-chip, and perhaps intra-chip applications are viable. This means that yet smaller devices are required as well as thermally stable devices, and multiple wavelength channels. In turn this demands smaller, more efficient modulators, athermal circuits, and improved wavelength division multiplexers. The debate continues as to whether on-chip lasers are necessary for all applications, but an efficient low cost laser would benefit many applications. Multi-layer photonics offers the possibility of increasing the complexity and effectiveness of a given area of chip real estate, but it is a demanding challenge. Low cost packaging (in particular, passive alignment of fibre to waveguide), and effective wafer scale testing strategies, are also essential for mass market applications. Whilst solutions to these challenges would enhance most applications, a derivative technology is emerging, that of Mid Infra-Red (MIR) silicon photonics. This field will build on existing developments, but will require key enhancements to facilitate functionality at longer wavelengths. In common with mainstream silicon photonics, significant developments have been made, but there is still much left to do. Here we summarise some of our recent work towards wafer scale testing, passive alignment, multiplexing, and MIR silicon photonics technology.

  7. Individual Differences in Scotopic Visual Acuity and Contrast Sensitivity: Genetic and Non-Genetic Influences

    PubMed Central

    Bartholomew, Alex J.; Lad, Eleonora M.; Cao, Dingcai; Bach, Michael; Cirulli, Elizabeth T.

    2016-01-01

    Despite the large amount of variation found in the night (scotopic) vision capabilities of healthy volunteers, little effort has been made to characterize this variation and factors, genetic and non-genetic, that influence it. In the largest population of healthy observers measured for scotopic visual acuity (VA) and contrast sensitivity (CS) to date, we quantified the effect of a range of variables on visual performance. We found that young volunteers with excellent photopic vision exhibit great variation in their scotopic VA and CS, and this variation is reliable from one testing session to the next. We additionally identified that factors such as Circadian preference, iris color, astigmatism, depression, sex and education have no significant impact on scotopic visual function. We confirmed previous work showing that the amount of time spent on the vision test influences performance and that laser eye surgery results in worse scotopic vision. We also showed a significant effect of intelligence and photopic visual performance on scotopic VA and CS, but all of these variables collectively explain <30% of the variation in scotopic vision. The wide variation seen in young healthy volunteers with excellent photopic vision, the high test-retest agreement, and the vast majority of the variation in scotopic vision remaining unexplained by obvious non-genetic factors suggests a strong genetic component. Our preliminary genome-wide association study (GWAS) of 106 participants ruled out any common genetic variants of very large effect and paves the way for future, larger genetic studies of scotopic vision. PMID:26886100

  8. Spatial and temporal acuity of visual perception can be enhanced selectively by attentional set.

    PubMed

    Correa, Angel; Nobre, Anna C

    2008-08-01

    The aim of this research was to study the relationship between perceptual judgments about space and time. If spatial and temporal judgments were dissociable, they should be modulated selectively by attention. We compared the effect of the attentional set upon fine-grained spatial versus temporal discrimination of visual perception in two experiments. Using identical sensory stimulation, we measured perceptual judgments on either the size of a small spatial gap or the duration of a brief temporal gap. The attentional set was manipulated by cuing the task that was most likely to be performed. In one experiment, a neutral cue was also used, to measure relative benefits and costs of spatial and temporal task sets. If the attentional set could be directed selectively to spatial and temporal task-relevant dimensions, performance on both spatial and temporal acuity tasks should be specifically modulated by task cuing. The results showed that the attentional set enhanced the speed and accuracy of perceptual judgments similarly on both spatial and temporal tasks. Moreover, accuracy in one task was selectively enhanced by attending to that task while remaining unaffected by attending to the alternative task. This finding suggests multiple mechanisms, by which visual processing of spatial and temporal features can be selectively prepared without interfering with one another.

  9. Dampening Spontaneous Activity Improves the Light Sensitivity and Spatial Acuity of Optogenetic Retinal Prosthetic Responses

    PubMed Central

    Barrett, John Martin; Hilgen, Gerrit; Sernagor, Evelyne

    2016-01-01

    Retinitis pigmentosa is a progressive retinal dystrophy that causes irreversible visual impairment and blindness. Retinal prostheses currently represent the only clinically available vision-restoring treatment, but the quality of vision returned remains poor. Recently, it has been suggested that the pathological spontaneous hyperactivity present in dystrophic retinas may contribute to the poor quality of vision returned by retinal prosthetics by reducing the signal-to-noise ratio of prosthetic responses. Here, we investigated to what extent blocking this hyperactivity can improve optogenetic retinal prosthetic responses. We recorded activity from channelrhodopsin-expressing retinal ganglion cells in retinal wholemounts in a mouse model of retinitis pigmentosa. Sophisticated stimuli, inspired by those used in clinical visual assessment, were used to assess light sensitivity, contrast sensitivity and spatial acuity of optogenetic responses; in all cases these were improved after blocking spontaneous hyperactivity using meclofenamic acid, a gap junction blocker. Our results suggest that this approach significantly improves the quality of vision returned by retinal prosthetics, paving the way to novel clinical applications. Moreover, the improvements in sensitivity achieved by blocking spontaneous hyperactivity may extend the dynamic range of optogenetic retinal prostheses, allowing them to be used at lower light intensities such as those encountered in everyday life. PMID:27650332

  10. A single cohort prospective trial of the immediate effects of spinal manipulation on visual acuity

    PubMed Central

    Athaide, Michelle; Rego, Carol; Budgell, Brian

    2016-01-01

    Introduction: There is no high quality evidence on which to judge the generalizability of isolated reports of improvement in vision following manipulation. The current paucity of research results also precludes the thoughtful design of a controlled, prospective clinical study. Hence, the purpose of the current study was to test the feasibility of conducting a clinical trial of the acute effects of spinal manipulation on visual acuity. Methods: New adult patients presenting to a community based chiropractic clinic were recruited into a single cohort prospective trial to determine the immediate effects of cervical spinal manipulation on visual acuity. Results: The experimental protocol was well accepted by patients and caused minimal or no disruption of the clinic routine. By some measures, chiropractic treatment was accompanied by statistically significant improvements in visual acuity. Discussion: The results of this study indicate that it is quite feasible to conduct a prospective, community based clinical study of the acute effects of spinal manipulation on visual acuity. PMID:27069271

  11. Night vision goggle visual acuity assessment: results of an interagency test

    NASA Astrophysics Data System (ADS)

    Task, H. Lee

    2001-08-01

    There are several parameters that are used to characterize the quality of a night vision goggle (NVG) such as resolution, gain, field-of-view, visual acuity, etc. One of the primary parameters is visual acuity or resolution of the NVG. These two terms are often used interchangeably primarily because of the measurement methods employed. The objectives of this paper are to present: (1) an argument as to why NVG visual acuity and resolution should be considered as distinctly different parameters, (2) descriptions of different methods of measuring visual acuity and resolution, and (3) the results of a blind test by several agencies to measure the resolution of the same two NVGs (four oculars).

  12. Implementing an obstetric triage acuity scale: interrater reliability and patient flow analysis.

    PubMed

    Smithson, David S; Twohey, Rachel; Rice, Tim; Watts, Nancy; Fernandes, Christopher M; Gratton, Robert J

    2013-10-01

    A 5-category Obstetric Triage Acuity Scale (OTAS) was developed with a comprehensive set of obstetrical determinants. The objectives of this study were as follows: (1) to test the interrater reliability of OTAS and (2) to determine the distribution of patient acuity and flow by OTAS level. To test the interrater reliability, 110 triage charts were used to generate vignettes and the consistency of the OTAS level assigned by 8 triage nurses was measured. OTAS performed with substantial (Kappa, 0.61 - 0.77, OTAS 1-4) and near perfect correlation (0.87, OTAS 5). To assess patient flow, the times to primary and secondary health care provider assessments and lengths of stay stratified by acuity were abstracted from the patient management system. Two-thirds of triage visits were low acuity (OTAS 4, 5). There was a decrease in length of stay (median [interquartile range], minutes) as acuity decreased from OTAS 1 (120.0 [156.0] minutes) to OTAS 3 (75.0 [120.8]). The major contributor to length of stay was time to secondary health care provider assessment and this did not change with acuity. The percentage of patients admitted to the antenatal or birthing unit decreased from 80% (OTAS 1) to 12% (OTAS 5). OTAS provides a reliable assessment of acuity and its implementation has allowed for triaging of obstetric patients based on acuity, and a more in-depth assessment of the patient flow. By standardizing assessment, OTAS allows for opportunities to improve performance and make comparisons of patient care and flow across organizations.

  13. Grating Visual Acuity Results in the Early Treatment for Retinopathy of Prematurity Study

    PubMed Central

    2015-01-01

    Objective To compare grating (resolution) visual acuity at 6 years of age in eyes that received early treatment (ET) for high-risk prethreshold retinopathy of prematurity (ROP) versus eyes that were managed conventionally (CM). Methods In a randomized clinical trial, infants with bilateral, high-risk prethreshold ROP (N=317) had one eye treated early at high-risk prethreshold disease and the other eye managed conventionally, and treated if ROP progressed to threshold severity. For asymmetric cases (N=84), the high-risk prethreshold eye was randomized to either ET or CM. Main Outcome Measures Grating visual acuity measured at 6 years of age by masked testers using Teller acuity cards. Results Monocular grating acuity results were obtained from 317 (86%) of 370 surviving children. Analysis of grating acuity results for all subjects with high-risk prethreshold ROP showed no statistically significant overall benefit for early treatment (18.1% vs 22.8% unfavorable outcome, P=0.08). When the 6-year grating acuity results were analyzed according to a clinical algorithm (high-risk Type 1 and high-risk Type 2 prethreshold ROP), a benefit was seen in Type 1 eyes (16.4% vs 25.2%, P=0.004) that were treated early, but not in Type 2 eyes (21.3% vs 15.9%, P=0.29). Conclusion Early treatment for eyes with Type 1 ROP improved grating acuity outcomes but early treatment for eyes with Type 2 ROP did not. Application to Clinical Medicine Type I eyes should be treated early; however, based on acuity results at age 6 years, Type 2 eyes should be cautiously monitored for progression to Type 1 ROP. Trial Registration NCT00027222 PMID:21746974

  14. Visual Acuity Testing: Feedback Affects Neither Outcome nor Reproducibility, but Leaves Participants Happier

    PubMed Central

    Bach, Michael; Schäfer, Kerstin

    2016-01-01

    Assessment of visual acuity is a well standardized procedure at least for expert opinions and clinical trials. It is often recommended not giving patients feedback on the correctness of their responses. As this viewpoint has not been quantitatively examined so far, we quantitatively assessed possible effects of feedback on visual acuity testing. In 40 normal participants we presented Landolt Cs in 8 orientations using the automated Freiburg Acuity Test (FrACT, acuity threshold was measured with an adaptive staircase procedure. In an ABCDDCBA scheme, trial-by-trial feedback was provided in 2 x 4 conditions: (A) no feedback, (B) acoustic signals indicating correctness, (C)visual indication of correct orientation, and (D) a combination of (B) and (C). After each run the participants judged comfort. Main outcome measures were absolute visual acuity (logMAR), its test-retest agreement (limits of agreement) and participants’ comfort estimates on a 5-step symmetric Likert scale. Feedback influenced acuity outcome significantly (p = 0.02), but with a tiny effect size: 0.02 logMAR poorer acuity for (D) compared to (A), even weaker effects for (B) and (C). Test-retest agreement was high (limits of agreement: ± 1.0 lines) and did not depend on feedback (p>0.5). The comfort ranking clearly differed, by 2 steps on the Likert scale: the condition (A)–no feedback–was on average “slightly uncomfortable”, the other three conditions were “slightly comfortable” (p<0.0001). Feedback affected neither reproducibility nor the acuity outcome to any relevant extent. The participants, however, reported markedly greater comfort with any kind of feedback. We conclude that systematic feedback (as implemented in FrACT) offers nothing but advantages for routine use. PMID:26824693

  15. The Effect of Signal-to-Noise Ratio on Visual Acuity Through Night Vision Goggles

    DTIC Science & Technology

    1991-02-01

    subjects in visuLal acuity performance with NVGs, it was concluded that further research should be conducted to examine the correlation between visual...the image intensifier tuho. Tile image intensifier tube is basically a light amplifier that is sensitive over tho spectral region of about 600nm to... excellent means of getting a sensitive measure of visual acuity. 2 Method 2.1 Subje;cts Twelve male volunteers participated in this study. ’he subjects

  16. Comparison of three night vision intensification tube technologies on resolution acuity: results from grating and Hoffman ANV-126 tasks

    NASA Astrophysics Data System (ADS)

    Macuda, Todd; Allison, Robert S.; Thomas, Paul; Truong, Long; Tang, Denis; Craig, Greg; Jennings, Sion

    2005-05-01

    Several methodologies have been used to determine resolution acuity through Night Vision Goggles. The present study compared NVG acuity estimates derived from the Hoffman ANV-126 and a standard psychophysical grating acuity task. For the grating acuity task, observers were required to discriminate between horizontal and vertical gratings according to a method of constant stimuli. Psychometric functions were generated from the performance data, and acuity thresholds were interpolated at a performance level of 70% correct. Acuity estimates were established at three different illumination levels (0.06-5X10-4 lux) for both procedures. These estimates were then converted to an equivalent Snellen value. The data indicate that grating acuity estimates were consistently better (i.e. lower scores) than acuity measures obtained from the Hoffman ANV-126. Furthermore significant differences in estimated acuity were observed using different tube technologies. In keeping with previous acuity investigations, although the Hoffman ANV-126 provides a rapid operational assessment of tube acuity, it is suggested that more rigorous psychophysical procedures such as the grating task described here be used to assess the real behavioural resolution of tube technologies.

  17. Early non-visual experience influences proprioceptive-spatial discrimination acuity in adulthood.

    PubMed

    Fiehler, Katja; Reuschel, Johanna; Rösler, Frank

    2009-02-01

    The present study tested whether non-visual spatial experience affects later acuity of space perception. Congenitally blind adults who differed in the age acquired spatial knowledge via an orientation and mobility (O&M) training and matched sighted controls performed passive arm movements and judged the direction of the sensed movement. Proprioceptive-spatial discrimination acuity was assessed by an adaptive psychophysical procedure in two spatial coding conditions. In the egocentric coding condition, participants judged whether the hand trajectory felt left- or right-tilted in reference to a straight trajectory aligned to the transverse horizontal plane of the body midline axis. In the allocentric coding condition, they indicated whether the hand trajectory felt acute- or obtuse-angled in reference to a right angle. Proprioceptive-spatial acuity of congenitally blind participants significantly covaried with the age they attended an O&M training. The earlier the congenitally blind participants started the O&M training the more accurate was their space perception. Congenitally blind participants who underwent an O&M training after the age of 12 years showed poorer acuity than sighted controls. Congenitally blind participants with an earlier O&M training, however, approached the performance level of the sighted controls. The observed improvement in spatial acuity was more pronounced when judgements were given on the basis of an allocentric than an egocentric frame of reference. These findings suggest that proprioceptive-spatial acuity in adulthood depends on non-visual spatial experience during early development.

  18. Plasticity of Binocularity and Visual Acuity Are Differentially Limited by Nogo Receptor

    PubMed Central

    Stephany, Céleste-Élise; Chan, Leanne L.H.; Parivash, Sherveen N.; Dorton, Hilary M.; Piechowicz, Mariel

    2014-01-01

    The closure of developmental critical periods consolidates neural circuitry but also limits recovery from early abnormal sensory experience. Degrading vision by one eye throughout a critical period both perturbs ocular dominance (OD) in primary visual cortex and impairs visual acuity permanently. Yet understanding how binocularity and visual acuity interrelate has proven elusive. Here we demonstrate the plasticity of binocularity and acuity are separable and differentially regulated by the neuronal nogo receptor 1 (NgR1). Mice lacking NgR1 display developmental OD plasticity as adults and their visual acuity spontaneously improves after prolonged monocular deprivation. Restricting deletion of NgR1 to either cortical interneurons or a subclass of parvalbumin (PV)-positive interneurons alters intralaminar synaptic connectivity in visual cortex and prevents closure of the critical period for OD plasticity. However, loss of NgR1 in PV neurons does not rescue deficits in acuity induced by chronic visual deprivation. Thus, NgR1 functions with PV interneurons to limit plasticity of binocularity, but its expression is required more extensively within brain circuitry to limit improvement of visual acuity following chronic deprivation. PMID:25164659

  19. Nurse-patient assignment models considering patient acuity metrics and nurses' perceived workload.

    PubMed

    Sir, Mustafa Y; Dundar, Bayram; Barker Steege, Linsey M; Pasupathy, Kalyan S

    2015-06-01

    Patient classification systems (PCSs) are commonly used in nursing units to assess how many nursing care hours are needed to care for patients. These systems then provide staffing and nurse-patient assignment recommendations for a given patient census based on these acuity scores. Our hypothesis is that such systems do not accurately capture workload and we conduct an experiment to test this hypothesis. Specifically, we conducted a survey study to capture nurses' perception of workload in an inpatient unit. Forty five nurses from oncology and surgery units completed the survey and rated the impact of patient acuity indicators on their perceived workload using a six-point Likert scale. These ratings were used to calculate a workload score for an individual nurse given a set of patient acuity indicators. The approach offers optimization models (prescriptive analytics), which use patient acuity indicators from a commercial PCS as well as a survey-based nurse workload score. The models assign patients to nurses in a balanced manner by distributing acuity scores from the PCS and survey-based perceived workload. Numerical results suggest that the proposed nurse-patient assignment models achieve a balanced assignment and lower overall survey-based perceived workload compared to the assignment based solely on acuity scores from the PCS. This results in an improvement of perceived workload that is upwards of five percent.

  20. Correlation analysis of proprioceptive acuity in ipsilateral position-matching and velocity-discrimination.

    PubMed

    Djupsjöbacka, Mats; Domkin, Dmitry

    2005-01-01

    In order to plan and control movements the central nervous system (CNS) needs to continuously keep track of the state of the musculoskeletal system. Therefore the CNS constantly uses sensory input from mechanoreceptors in muscles, joints and skin to update information about body configuration on different levels of the CNS. On the conscious level, such representations constitute proprioception. Different tests for assessment of proprioceptive acuity have been described. However, it is unclear if the proprioceptive acuity measurements in these tests correlate within subjects. By using both uni- and multivariate analysis we compared proprioceptive acuity in different variants of ipsilateral active and passive limb position-matching and ipsilateral passive limb movement velocity-discrimination in a group of healthy subjects. The analysis of the position-matching data revealed a higher acuity of matching for active movements in comparison to passive ones. The acuity of matching was negatively correlated to movement extent. There was a lack of correlation between proprioceptive acuity measurements in position-matching and velocity-discrimination.

  1. Effects of molting on the visual acuity of the blue crab, Callinectes sapidus.

    PubMed

    Baldwin, Jamie; Johnsen, Sönke

    2011-09-15

    In crustaceans with compound eyes, the corneal lens of each facet is part of the exoskeleton and thus shed during molting. Here we used an optomotor assay to evaluate the impact of molting on visual acuity (as measured by the minimum resolvable angle, α(min)) in the female blue crab, Callinectes sapidus. We found that visual acuity decreases substantially in the days prior to molting and is gradually recovered after molting. Four days prior to molting, α(min) was 1.8 deg (N=5), a value approximating the best possible acuity in this species. In the 24 h before ecdysis occurred, α(min) increased to 15.0 deg (N=12), corresponding to an eightfold drop in visual acuity. Within 6 days after molting, α(min) returned to the pre-molting value. Micrographs of C. sapidus eyes showed that a gap between the corneal lens and the crystalline cone first appeared approximately 5 days prior to shedding and increased in width as the process progressed. This separation was likely responsible for the loss of visual acuity observed in behavioral tests. In blue crabs, mating is limited to the period of the female's pubertal molt, and a reduction in acuity during this time may have an effect on the sensory cues used in female mate choice. The results described here may be broadly applicable to all arthropods that molt and have particular importance for crustaceans that molt multiple times in their lifetime or have mating cycles that are paired with molting.

  2. Restoring Visual Acuity in Dynamic Conditions with a Vestibular Implant

    PubMed Central

    Guinand, Nils; Van de Berg, Raymond; Cavuscens, Samuel; Stokroos, Robert; Ranieri, Maurizio; Pelizzone, Marco; Kingma, Herman; Guyot, Jean-Philippe; Pérez Fornos, Angélica

    2016-01-01

    Vestibular implants are devices designed to rehabilitate patients with a bilateral vestibular loss (BVL). These patients lack a properly functioning vestibulo-ocular reflex (VOR), which impairs gaze stabilization abilities and results in an abnormal loss of visual acuity (VA) in dynamic situations (i.e., severely limiting the patient's ability to read signs or recognize faces while walking). We previously demonstrated that the VOR can be artificially restored in a group of BVL patients fitted with a prototype vestibular implant. This study was designed to investigate whether these promising results could be translated to a close-to-reality task, significantly improving VA abilities while walking. Six BVL patients previously implanted with a vestibular implant prototype participated in the experiments. VA was determined using Sloan letters displayed on a computer screen, in four conditions: (1) with the patient standing still without moving (static), (2) while the patient was walking on a treadmill at constant speed with the vestibular implant prototype turned off (systemOFF), (3) while the patient was walking on a treadmill at constant speed with the vestibular implant prototype turned on providing coherent motion information (systemONmotion), and (4) a “placebo” condition where the patient was walking on a treadmill at constant speed with the vestibular implant prototype turned on providing reversed motion information (systemONsham). The analysis (one-way repeated measures analysis of variance) revealed a statistically significant effect of the test condition [F(3, 12) = 30.5, p < 0.001]. Significant decreases in VA were observed with the systemOFF condition when compared to the static condition (Tukey post-hoc p < 0.001). When the vestibular implant was turned on, delivering pertinent motion information (systemONmotion) the VA improved to close to normal values. The improvement disappeared in the placebo condition (systemONsham) and VA-values also dropped

  3. Early Quick Acuity Score Provides More Complete Data on Emergency Department Walkouts

    PubMed Central

    Lovett, Paris B.; Kahn, J. Akiva; Greene, Stuart E.; Bloch, Matthew A.; Brandt, Daniel R.; Minckler, Michael R.

    2014-01-01

    Introduction Many prior studies have compared the acuity of Emergency Department (ED) patients who have Left Without Being Seen (LWBS) against non-LWBS patients. A weakness in these studies is that patients may walk out prior to the assignment of a triage score, biasing comparisons. We report an operational change whereby acuity was assessed immediately upon patient arrival. We hypothesized more patients would receive acuity scores with EQAS. We also sought to compare LWBS and non-LWBS patient characteristics with reduced bias. Methods Setting: urban, academic medical center. Retrospective cohort study, electronic chart review, collecting data on all ED patients presenting between 4/1/2010 and 10/31/2011 (“Traditional Acuity Score” period, TAS) and from 11/1/2011 to 3/31/2012 (“Early Quick Acuity Score” period, EQAS). We recorded disposition (LWBS versus non-LWBS), acuity and demographics. For each subject during the EQAS period, we calculated how many prior ED visits and how many prior walkouts the subject had had during the TAS period. Results Acuity was recorded in 92,275 of 94,526 patients (97.6%) for TAS period, and 25,577 of 25,760 patients (99.3%) for EQAS period, a difference of 1.7% (1.5%, 1.8%). LWBS patients had acuity scores recorded in 5,180 of 7,040 cases (73.6%) during TAS period, compared with 897 of 1,010 cases (88.8%) during the EQAS period, a difference of 15.2% (14.8%, 15.7%). LWBS were more likely than non-LWBS to be male, were younger and had lower acuity scores. LWBS averaged 5.3 prior ED visits compared with 2.8 by non-LWBS, a difference of 2.5 (1.5, 3.5). LWBS averaged 1.3 prior ED walkouts compared with 0.2 among non-LWBS, a difference of 1.1 (0.8, 1.3). Conclusions EQAS resulted in a higher proportion of patients receiving acuity scores, particularly among LWBS. This offers more complete data when comparing LWBS and non-LWBS patient characteristics. The comparison reinforced findings from prior studies. PMID:24465699

  4. Measuring the Influence of Galilean Loupe System on Near Visual Acuity of Dentists under Simulated Clinical Conditions

    PubMed Central

    Urlic, Iris; Verzak, Željko; Vranic, Dubravka Negovetic

    2016-01-01

    Aim The purpose of this study was to compare near visual acuity of dentists without optical aids (VSC) with near visual acuity of those using the Galilean telescope system (VGA2) with magnification of x 2.5, and the distance of 350 mm in simulated clinical conditions. Methods The study included 46 dentists (visual acuity 1.0 without correction). A visual acuity testing was carried out using a miniaturized Snellen visual acuity chart which was placed in the cavity of molar teeth mounted in a phantom head in simulated clinical conditions. Near visual acuity for the vicinity was examined: 1) without correction at a distance of 300-400 mm (VSC); 2) with Galilean loupes with magnification of x2.5, focal length of 350mm. Results The distributions of near visual acuity recorded using VSC and VGA2, 5 systems were compared by the Wilcoxon Signed Rank test. The results obtained by Wilcoxon Signed Rank test pointed to a statistically significant difference in the distribution of recorded visual acuity between the VSC and VGA2 optical systems (W = - 403.5; p <0.001). Conclusion If using the VGA2, 5 systems, higher values of the near visual acuity were recorded and subsequently compared to near visual acuity without magnifying aids (VSC). PMID:27847397

  5. Closed surfaces of constant visual acuity in symmetric dioptric power space.

    PubMed

    Rubin, A; Harris, W F

    2001-10-01

    This paper demonstrates a multivariate approach to understanding the complicated relations of visual acuity to refractive state or ametropia. Other approaches, as previously used, included graphical representations of lines or profiles of iso-oxyopia (Peters, 1961). But one limitation of Peters' method is that cylinder axis was ignored. However, here the relationship between visual acuity and refractive power will be represented by estimated closed surfaces of constant visual acuity in symmetric dioptric power space. At or near the common center (of several closed surfaces, for example) is the refractive compensation. Coming outwards from such a center, the visual acuity drops in all directions in the space. The primary purpose of this paper was to present estimated closed surfaces of constant visual acuity for several eyes. Various procedures were performed on several subjects including measurement of iris aperture diameter, subjective refraction, and autorefraction. Thereafter, an automated phoropter and either Jackson cross-cylinders or spheres were used to influence dioptric blur or defocus in the subjects. The visual stimulus was a computer-generated nondirectional or meridionally independent letter O. Ovoidal surfaces fit the measurements obtained (with Jackson cross-cylinders and spheres) better than ellipsoidal surfaces. The cross-section, in symmetric dioptric power space, at powers with the same nearest equivalent sphere as the refractive compensation is elliptical in many cases and reflects a dependence of visual acuity on cylinder axis. The surfaces differ when powers are changed so that one is moving away from (decompensation surfaces) or toward (accompensation surfaces) the refractive compensation. The multivariate and graphical methods used in this paper probably have implications for the direction of future research in a number of areas involving measures of vision function such as autorefraction, retinoscopy, subjective refraction, and visual

  6. Effect of Target Location on Dynamic Visual Acuity During Passive Horizontal Rotation

    NASA Technical Reports Server (NTRS)

    Appelbaum, Meghan; DeDios, Yiri; Kulecz, Walter; Peters, Brian; Wood, Scott

    2010-01-01

    The vestibulo-ocular reflex (VOR) generates eye rotation to compensate for potential retinal slip in the specific plane of head movement. Dynamic visual acuity (DVA) has been utilized as a functional measure of the VOR. The purpose of this study was to examine changes in accuracy and reaction time when performing a DVA task with targets offset from the plane of rotation, e.g. offset vertically during horizontal rotation. Visual acuity was measured in 12 healthy subjects as they moved a hand-held joystick to indicate the orientation of a computer-generated Landolt C "as quickly and accurately as possible." Acuity thresholds were established with optotypes presented centrally on a wall-mounted LCD screen at 1.3 m distance, first without motion (static condition) and then while oscillating at 0.8 Hz (DVA, peak velocity 60 deg/s). The effect of target location was then measured during horizontal rotation with the optotypes randomly presented in one of nine different locations on the screen (offset up to 10 deg). The optotype size (logMar 0, 0.2 or 0.4, corresponding to Snellen range 20/20 to 20/50) and presentation duration (150, 300 and 450 ms) were counter-balanced across five trials, each utilizing horizontal rotation at 0.8 Hz. Dynamic acuity was reduced relative to static acuity in 7 of 12 subjects by one step size. During the random target trials, both accuracy and reaction time improved proportional to optotype size. Accuracy and reaction time also improved between 150 ms and 300 ms presentation durations. The main finding was that both accuracy and reaction time varied as a function of target location, with greater performance decrements when acquiring vertical targets. We conclude that dynamic visual acuity varies with target location, with acuity optimized for targets in the plane of motion. Both reaction time and accuracy are functionally relevant DVA parameters of VOR function.

  7. A double dissociation of the acuity and crowding limits to letter identification, and the promise of improved visual screening.

    PubMed

    Song, Shuang; Levi, Dennis M; Pelli, Denis G

    2014-05-05

    Here, we systematically explore the size and spacing requirements for identifying a letter among other letters. We measure acuity for flanked and unflanked letters, centrally and peripherally, in normals and amblyopes. We find that acuity, overlap masking, and crowding each demand a minimum size or spacing for readable text. Just measuring flanked and unflanked acuity is enough for our proposed model to predict the observer's threshold size and spacing for letters at any eccentricity. We also find that amblyopia in adults retains the character of the childhood condition that caused it. Amblyopia is a developmental neural deficit that can occur as a result of either strabismus or anisometropia in childhood. Peripheral viewing during childhood due to strabismus results in amblyopia that is crowding limited, like peripheral vision. Optical blur of one eye during childhood due to anisometropia without strabismus results in amblyopia that is acuity limited, like blurred vision. Furthermore, we find that the spacing:acuity ratio of flanked and unflanked acuity can distinguish strabismic amblyopia from purely anisometropic amblyopia in nearly perfect agreement with lack of stereopsis. A scatter diagram of threshold spacing versus acuity, one point per patient, for several diagnostic groups, reveals the diagnostic power of flanked acuity testing. These results and two demonstrations indicate that the sensitivity of visual screening tests can be improved by using flankers that are more tightly spaced and letter like. Finally, in concert with Strappini, Pelli, Di Pace, and Martelli (submitted), we jointly report a double dissociation between acuity and crowding. Two clinical conditions-anisometropic amblyopia and apperceptive agnosia-each selectively impair either acuity A or the spacing:acuity ratio S/A, not both. Furthermore, when we specifically estimate crowding, we find a double dissociation between acuity and crowding. Models of human object recognition will need to

  8. A double dissociation of the acuity and crowding limits to letter identification, and the promise of improved visual screening

    PubMed Central

    Song, Shuang; Levi, Dennis M.; Pelli, Denis G.

    2014-01-01

    Here, we systematically explore the size and spacing requirements for identifying a letter among other letters. We measure acuity for flanked and unflanked letters, centrally and peripherally, in normals and amblyopes. We find that acuity, overlap masking, and crowding each demand a minimum size or spacing for readable text. Just measuring flanked and unflanked acuity is enough for our proposed model to predict the observer's threshold size and spacing for letters at any eccentricity. We also find that amblyopia in adults retains the character of the childhood condition that caused it. Amblyopia is a developmental neural deficit that can occur as a result of either strabismus or anisometropia in childhood. Peripheral viewing during childhood due to strabismus results in amblyopia that is crowding limited, like peripheral vision. Optical blur of one eye during childhood due to anisometropia without strabismus results in amblyopia that is acuity limited, like blurred vision. Furthermore, we find that the spacing:acuity ratio of flanked and unflanked acuity can distinguish strabismic amblyopia from purely anisometropic amblyopia in nearly perfect agreement with lack of stereopsis. A scatter diagram of threshold spacing versus acuity, one point per patient, for several diagnostic groups, reveals the diagnostic power of flanked acuity testing. These results and two demonstrations indicate that the sensitivity of visual screening tests can be improved by using flankers that are more tightly spaced and letter like. Finally, in concert with Strappini, Pelli, Di Pace, and Martelli (submitted), we jointly report a double dissociation between acuity and crowding. Two clinical conditions—anisometropic amblyopia and apperceptive agnosia—each selectively impair either acuity A or the spacing:acuity ratio S/A, not both. Furthermore, when we specifically estimate crowding, we find a double dissociation between acuity and crowding. Models of human object recognition will need

  9. The strong connection between sensory and cognitive performance in old age: not due to sensory acuity reductions operating during cognitive assessment.

    PubMed

    Lindenberger, U; Scherer, H; Baltes, P B

    2001-06-01

    Cognitive aging research has documented a strong increase in the covariation between sensory and cognitive functioning with advancing age. In part, this finding may reflect sensory acuity reductions operating during cognitive assessment. To examine this possibility, the authors administered cognitive tasks used in prior studies (e.g., Lindenberger & Baltes, 1994) to middle-aged adults under age-simulation conditions of reduced visual acuity, auditory acuity, or both. Visual acuity was lowered through partial occlusion filters, and auditory acuity through headphone-shaped noise protectors. Acuity manipulations reduced visual acuity and auditory acuity in the speech range to values reaching or approximating old-age acuity levels, respectively, but did not lower cognitive performance relative to control conditions. Results speak against assessment-related sensory acuity accounts of the age-related increase in the connection between sensory and cognitive functioning and underscore the need to explore alternative explanations, including a focus on general aspects of brain aging.

  10. Bevacizumab injection in patients with age-related macular degeneration associated with poor initial visual acuity.

    PubMed

    El Matri, Leila; Bouraoui, Rym; Chebil, Ahmed; Kort, Fedra; Bouladi, Mejda; Limaiem, Rym; Landoulsi, Hana

    2012-01-01

    Purpose. To evaluate functional and anatomic effects of intravitreal bevacizumab in patients with neovascular AMD and initial low visual acuity. Methods. Retrospective case series of 38 eyes with neovascular AMD and initial visual acuity of 20/200 or less, treated with intravitreal bevacizumab injection. Results. Mean followup was 14.1 months ±  7.1 (range: 5 to 24 months). Mean logMAR vision at baseline was 1.38 logMAR ±  0.33, at 6 months was 1.14 logMAR ±  0.37 (P = 0.001) and at 12 months was 1.22 logMar ±  0.33 (P = 0.004). Mean baseline central retinal thickness was 431 μm ±  159.7 at 6 months was 293.43 μm  ±  122.79 (P = 10(-4)) and at 12 months was 293.1 μm  ±  130 (P = 0.004). Visual acuity improved in both patients with or without prior PDT treatment. Conclusions. Intravitreal bevacizumab injection may increase the chance of visual acuity gain in neovascular AMD even in cases with initial low visual acuity.

  11. Out of sight, out of mind? Relations between visual acuity and cognition.

    PubMed

    La Fleur, Claire G; Salthouse, Timothy A

    2014-10-01

    Prior research has established significant relations between measures of sensory ability and cognitive function in adults of different ages, and several explanations for this relation have been proposed. One explanation is that sensory abilities restrict cognitive processing, a second is that cognitive abilities influence assessments of sensory ability, and a third is that both sensory function and cognition are affected by a common, potentially age-based, third factor. These explanations were investigated using mediation and moderation analyses, with near visual acuity as the sensory measure and scores on visual speed tests and auditory memory tests as the cognitive measures. Measures of visual acuity, speed, and memory were obtained from three moderately large samples, two cross-sectional (N = 380, N = 4,779) and one longitudinal (N = 2,258), with participants ranging from 18 to 90 years of age. The visual acuity and cognitive measures had different age trajectories, and the visual acuity-cognition relations were similar in each 5-year age band. The results suggest that the age-related differences and changes in near visual acuity are unlikely to contribute to the age-related differences and changes in speed and memory measures.

  12. Dot Display Affects Approximate Number System Acuity and Relationships with Mathematical Achievement and Inhibitory Control

    PubMed Central

    Norris, Jade Eloise; Castronovo, Julie

    2016-01-01

    Much research has investigated the relationship between the Approximate Number System (ANS) and mathematical achievement, with continued debate surrounding the existence of such a link. The use of different stimulus displays may account for discrepancies in the findings. Indeed, closer scrutiny of the literature suggests that studies supporting a link between ANS acuity and mathematical achievement in adults have mostly measured the ANS using spatially intermixed displays (e.g. of blue and yellow dots), whereas those failing to replicate a link have primarily used spatially separated dot displays. The current study directly compared ANS acuity when using intermixed or separate dots, investigating how such methodological variation mediated the relationship between ANS acuity and mathematical achievement. ANS acuity was poorer and less reliable when measured with intermixed displays, with performance during both conditions related to inhibitory control. Crucially, mathematical achievement was significantly related to ANS accuracy difference (accuracy on congruent trials minus accuracy on incongruent trials) when measured with intermixed displays, but not with separate displays. The findings indicate that methodological variation affects ANS acuity outcomes, as well as the apparent relationship between the ANS and mathematical achievement. Moreover, the current study highlights the problem of low reliabilities of ANS measures. Further research is required to construct ANS measures with improved reliability, and to understand which processes may be responsible for the increased likelihood of finding a correlation between the ANS and mathematical achievement when using intermixed displays. PMID:27195749

  13. Transcranial direct current stimulation improves visual acuity in amblyopic Long-Evans rats.

    PubMed

    Castaño-Castaño, S; Garcia-Moll, A; Morales-Navas, M; Fernandez, E; Sanchez-Santed, F; Nieto-Escamez, F

    2017-02-15

    Transcranial direct current stimulation (tDCS) has proved to increase brain cortex plasticity and different models of brain damage. In this work, we have analyzed the effects of tDCS in an experimental model of amblyopia using Long-Evans rats. Animals were monocularly deprived between 12 and 75 postnatal days and visual cortex contralateral to the deprived eye was stimulated using anodal tDCS during 8days (20min/day). The effects of tDCS treatment on the visual function were evaluated by using the optomotor reflex of the animals as a measure of visual acuity. Results obtained indicate that monocular occlusion during the critical period lead to a reduction of visual acuity in monocular and binocular conditions. Stimulation with anodal tDCS produced a nearly full recovery in visual acuity of amblyopic animals. However, same stimulation protocol in healthy control animals produced a decrease of binocular visual acuity. These data indicate that tDCS can reverse the effects of monocular deprivation on visual acuity, although it is essential to use this technique in a controlled way due to the possible adverse effects on healthy individuals.

  14. Robot-Aided Mapping of Wrist Proprioceptive Acuity across a 3D Workspace

    PubMed Central

    Marini, Francesca; Squeri, Valentina; Morasso, Pietro; Konczak, Jürgen; Masia, Lorenzo

    2016-01-01

    Proprioceptive signals from peripheral mechanoreceptors form the basis for bodily perception and are known to be essential for motor control. However we still have an incomplete understanding of how proprioception differs between joints, whether it differs among the various degrees-of-freedom (DoFs) within a particular joint, and how such differences affect motor control and learning. We here introduce a robot-aided method to objectively measure proprioceptive function: specifically, we systematically mapped wrist proprioceptive acuity across the three DoFs of the wrist/hand complex with the aim to characterize the wrist position sense. Thirty healthy young adults performed an ipsilateral active joint position matching task with their dominant wrist using a haptic robotic exoskeleton. Our results indicate that the active wrist position sense acuity is anisotropic across the joint, with the abduction/adduction DoF having the highest acuity (the error of acuity for flexion/extension is 4.64 ± 0.24°; abduction/adduction: 3.68 ± 0.32°; supination/pronation: 5.15 ± 0.37°) and they also revealed that proprioceptive acuity decreases for smaller joint displacements. We believe this knowledge is imperative in a clinical scenario when assessing proprioceptive deficits and for understanding how such sensory deficits relate to observable motor impairments. PMID:27536882

  15. A comparison of the effects of ageing upon vernier and bisection acuity.

    PubMed

    Garcia-Suarez, Luis; Barrett, Brendan T; Pacey, Ian

    2004-05-01

    While most positional acuity tasks exhibit an age-related decline in performance, the effect of ageing upon vernier acuity continues to be the subject of some debate. In the present study we employed a stimulus design that enabled the simultaneous determination of bisection and vernier acuities in 36 subjects, aged between 22 and 84 years. This approach provided a means for directly testing the hypothesis that ageing affects bisection acuity but not vernier acuity by ensuring that differences in stimulus configuration and in the subject's task were kept to an absolute minimum. Optimum thresholds increased as a function of age for both bisection and vernier tasks. Inter-subject threshold variability also increased with age. Issues surrounding the comparison of absolute vernier thresholds across different studies are discussed and two important methodological factors are identified: the precise statistical method used to estimate thresholds, and the magnitude, in angular terms, of the smallest spatial offset of the elements of the vernier stimulus which can be displayed. Comparison with previously published data indicates that the discrepancy between this study and most previous investigations with respect to the effect of age upon vernier performance can be at least partly accounted for by differences in the minimum displayable vernier offset. Vernier thresholds do increase with age. The increased variability of vernier thresholds in older subjects would appear to limit the diagnostic value of the test as a means of enabling normal ageing to be distinguished from visual loss due to pathology of the eye or visual system.

  16. Relation between Approximate Number System Acuity and Mathematical Achievement: The Influence of Fluency

    PubMed Central

    Wang, Li; Sun, Yuhua; Zhou, Xinlin

    2016-01-01

    Previous studies have observed inconsistent relations between the acuity of the Approximate Number System (ANS) and mathematical achievement. In this paper, we hypothesize that the relation between ANS acuity and mathematical achievement is influenced by fluency; that is, the mathematical achievement test covering a greater expanse of mathematical fluency may better reflect the relation between ANS acuity and mathematics skills. We explored three types of mathematical achievement tests utilized in this study: Subtraction, graded, and semester-final examination. The subtraction test was designed to measure the mathematical fluency. The graded test was more fluency-based than the semester-final examination, but both involved the same mathematical knowledge from the class curriculum. A total of 219 fifth graders from primary schools were asked to perform all three tests, then given a numerosity comparison task, a visual form perception task (figure matching), and a series of other tasks to assess general cognitive processes (mental rotation, non-verbal matrix reasoning, and choice reaction time). The findings were consistent with our expectations. The relation between ANS acuity and mathematical achievement was particularly clearly reflected in the participants’ performance on the visual form perception task, which supports the domain-general explanations for the underlying mechanisms of the relation between ANS acuity and math achievement. PMID:28066291

  17. Relation between Approximate Number System Acuity and Mathematical Achievement: The Influence of Fluency.

    PubMed

    Wang, Li; Sun, Yuhua; Zhou, Xinlin

    2016-01-01

    Previous studies have observed inconsistent relations between the acuity of the Approximate Number System (ANS) and mathematical achievement. In this paper, we hypothesize that the relation between ANS acuity and mathematical achievement is influenced by fluency; that is, the mathematical achievement test covering a greater expanse of mathematical fluency may better reflect the relation between ANS acuity and mathematics skills. We explored three types of mathematical achievement tests utilized in this study: Subtraction, graded, and semester-final examination. The subtraction test was designed to measure the mathematical fluency. The graded test was more fluency-based than the semester-final examination, but both involved the same mathematical knowledge from the class curriculum. A total of 219 fifth graders from primary schools were asked to perform all three tests, then given a numerosity comparison task, a visual form perception task (figure matching), and a series of other tasks to assess general cognitive processes (mental rotation, non-verbal matrix reasoning, and choice reaction time). The findings were consistent with our expectations. The relation between ANS acuity and mathematical achievement was particularly clearly reflected in the participants' performance on the visual form perception task, which supports the domain-general explanations for the underlying mechanisms of the relation between ANS acuity and math achievement.

  18. Quantitative assessment of visual acuity in projective head-mounted displays

    NASA Astrophysics Data System (ADS)

    Fidopiastis, Cali M.; Meyer, Catherine; Fuhrman, Christopher A.; Rolland, Jannick P.

    2003-09-01

    One issue of head mounted display design relates to the tradeoff between field of view (FOV) and resolution, which can lead to reduced visual acuity (VA). Essentially, an increase in FOV causes a decrease in visual acuity, for a given LCD display that has a fixed number of pixels. The effects of enhanced brightness on VA using two different types of retro-reflective material (cubed or beaded) were tested using a 52 deg. FOV projective helmet mounted display with VGA resolution. Three lighting conditions were also tested. Based on the display size, resolution, and FOV, we estimated a maximum visual acuity of 4.1 minutes of arc. In a counter-balanced between measures design, subjects' psychometric acuity functions were determined using a computer-generated 4AFC Landolt C test presented stereoscopically and probit analysis. The results confirmed that the maximum visual acuity possible within the setup was 4.1 arc minutes, the limit imposed by the microdisplay, and not the retroreflective material.

  19. Determine the effect of neck muscle fatigue on dynamic visual acuity in healthy young adults

    PubMed Central

    Al Saif, Amer A.; Al Senany, Samira

    2015-01-01

    [Purpose] The aim of this study was to determine whether neck muscle fatigue affects dynamic visual acuity in healthy young participants. [Subjects and Methods] This study was a double-blinded, prospective, randomized, controlled trial. Thirty healthy young subjects (ages 21 to 30 years) participated in the study. Participants were randomly divided into an experimental group (n=15) and a control group (n=15). The experimental group performed an exercise designed to induce neck muscle fatigue and the control group preformed non-fatiguing sham exercises. [Results] There were significant differences in mean dynamic visual acuity between the two groups (0.26±0.11 LogMar versus 0.003±0.02 LogMar). Subjects in the experimental group showed a significant decline in their dynamic visual acuity compared with the control group. Dynamic visual acuity strongly correlated with neck muscle fatigue (r = 0.79). No significant differences in joint position error were observed between the two groups and no significant correlations between joint position error and neck muscle fatigue were observed (r = 0.23). [Conclusion] The results of this study suggest that neck muscle fatigue negatively impacts dynamic visual acuity. Although not statistically significant, cervical spine proprioception as measured by the joint position error in the experimental group was diminished after fatigue. PMID:25642087

  20. Determine the effect of neck muscle fatigue on dynamic visual acuity in healthy young adults.

    PubMed

    Al Saif, Amer A; Al Senany, Samira

    2015-01-01

    [Purpose] The aim of this study was to determine whether neck muscle fatigue affects dynamic visual acuity in healthy young participants. [Subjects and Methods] This study was a double-blinded, prospective, randomized, controlled trial. Thirty healthy young subjects (ages 21 to 30 years) participated in the study. Participants were randomly divided into an experimental group (n=15) and a control group (n=15). The experimental group performed an exercise designed to induce neck muscle fatigue and the control group preformed non-fatiguing sham exercises. [Results] There were significant differences in mean dynamic visual acuity between the two groups (0.26±0.11 LogMar versus 0.003±0.02 LogMar). Subjects in the experimental group showed a significant decline in their dynamic visual acuity compared with the control group. Dynamic visual acuity strongly correlated with neck muscle fatigue (r = 0.79). No significant differences in joint position error were observed between the two groups and no significant correlations between joint position error and neck muscle fatigue were observed (r = 0.23). [Conclusion] The results of this study suggest that neck muscle fatigue negatively impacts dynamic visual acuity. Although not statistically significant, cervical spine proprioception as measured by the joint position error in the experimental group was diminished after fatigue.

  1. The Role of Libraries in Web-Based Distance Education: An Account and an Analysis of the Impact of Web Technology on Distance Learning--What Remains Unchanged, What Is Changing

    ERIC Educational Resources Information Center

    Cooke, Nicole A.

    2004-01-01

    Even though distance education has a long and diverse history, dating back to 1840, in the last ten-to-fifteen years it has been completely transformed by the emergence of Web-based technology. This technology has had an enormous impact on all aspects of distance education (or distance learning as it is increasingly called). In addition to…

  2. ["Should the staff's attitude towards the patients remain unchanged, I will not guarantee anything." Protest masculinity and coping of "rebellious patients" at the Heidelberg University Psychiatric Hospital on the eve of deinstitutionalization].

    PubMed

    Schwamm, Christoph

    2015-01-01

    This article analyses the illness experiences of male patients from the Heidelberg University Psychiatric Hospital during the protests against Psychiatry in the year 1973. Protest is one of the most important expressions of masculinity in socially disadvantaged men, such as men with mental disorders. The analysis of 100 medical records shows that some patients tried to construct themselves as men in a way that was explicitly motivated by antipsychiatric ideas: They questioned psychiatric authority, behaved "sexually inappropriate", or used drugs. On the eve of psychiatric reform in West Germany those patients were well aware that the alternative--complying with the treatment--would put them at considerable risk. In addition to the usual inference of hegemonic or normative masculinities as risk-factors, the behavior of those ,,rebellious patients" has to be interpreted as individual coping strategies.

  3. Acquisition of the Cardinal Principle Coincides with Improvement in Approximate Number System Acuity in Preschoolers

    PubMed Central

    Shusterman, Anna; Slusser, Emily; Halberda, Justin; Odic, Darko

    2016-01-01

    Human mathematical abilities comprise both learned, symbolic representations of number and unlearned, non-symbolic evolutionarily primitive cognitive systems for representing quantities. However, the mechanisms by which our symbolic (verbal) number system becomes integrated with the non-symbolic (non-verbal) representations of approximate magnitude (supported by the Approximate Number System, or ANS) are not well understood. To explore this connection, forty-six children participated in a 6-month longitudinal study assessing verbal number knowledge and non-verbal numerical acuity. Cross-sectional analyses revealed a strong relationship between verbal number knowledge and ANS acuity. Longitudinal analyses suggested that increases in ANS acuity were most strongly related to the acquisition of the cardinal principle, but not to other milestones of verbal number acquisition. These findings suggest that experience with culture and language is intimately linked to changes in the properties of a core cognitive system. PMID:27078257

  4. The role of numeracy and approximate number system acuity in predicting value and probability distortion.

    PubMed

    Patalano, Andrea L; Saltiel, Jason R; Machlin, Laura; Barth, Hilary

    2015-12-01

    It is well documented that individuals distort outcome values and probabilities when making choices from descriptions, and there is evidence of systematic individual differences in distortion. In the present study, we investigated the relationship between individual differences in such distortions and two measures of numerical competence, numeracy and approximate number system (ANS) acuity. Participants indicated certainty equivalents for a series of simple monetary gambles, and data were used to estimate individual-level value and probability distortion, using a cumulative prospect theory framework. We found moderately strong negative correlations between numeracy and value and probability distortion, but only weak and non-statistically reliable correlations between ANS acuity and distortions. We conclude that low numeracy contributes to number distortion in decision making, but that approximate number system acuity might not underlie this relationship.

  5. Compared optical performances of multifocal and monofocal intraocular lenses (contrast sensitivity and dynamic visual acuity)

    PubMed Central

    Williamson, W; Poirier, L; Coulon, P; Verin, P

    1994-01-01

    The functional results (contrast sensitivity and dynamic visual acuity) of 19 multifocal (3M design) and 14 all polymethylmethacrylate biconvex monofocal intraocular lenses (IOLs), 6 mm in optical diameter were compared. Best corrected visual acuity was > or = 8/10 (Monoyer chart) Parinaud 2 in all cases. Major differences of functional performance in favour of monofocal IOLs were found outside standard conditions of vision (low contrast and illumination levels). A significant difference in contrast sensitivity was found for each spatial frequency in favour of multifocal IOLs (0.0016 < p < 0.05). Mesopic vision was statistically higher in the monofocal IOL group (p = 0.0015). Moreover, dynamic visual acuity allowed accurate evaluation of the difference in performance between these two models of implant. In view of these results multifocal IOLs should be reserved for patients with normal psychosensitive adaptation; an ocular pathology that could alter contrast sensitivity or mesopic vision is a contraindication for multifocal IOLs. PMID:8199107

  6. Sensorimotor posture control in the blind: superior ankle proprioceptive acuity does not compensate for vision loss.

    PubMed

    Ozdemir, Recep A; Pourmoghaddam, Amir; Paloski, William H

    2013-09-01

    To better understand sensorimotor posture control differences between blind and sighted individuals, we examined the role of ankle joint proprioception and ankle muscle strength on postural control in healthy blind (n=13, 25-58 years) and age- and sex-matched sighted (n=15, 20-65 years) volunteers. We measured ankle joint proprioceptive acuity and isokinetic muscle strength in plantarflexion and dorsiflexion using an isokinetic dynamometer. We also assessed postural control performance during quiet bipedal stance with and without sudden postural perturbations, and during quiet unipedal stance. We found that while our blind subjects exhibited significantly better proprioceptive acuity than our sighted subjects their postural control performance was significantly poorer than that of the sighted group with eyes open, and no different from that of the sighted group with eyes closed suggesting that their superior proprioceptive acuity does not translate to improved balance control.

  7. The effects of time, luminance, and high contrast targets: revisiting grating acuity in the domestic cat.

    PubMed

    Clark, Daria L; Clark, Robert A

    2013-11-01

    Based on optical clarity and retinal cone density, the cat has a potential acuity of 20-30 cycles per degree (cpd), yet most behavioral studies estimate feline acuity between 3 and 9 cpd. Those studies, however, were limited by restrictive experimental conditions that may have inadvertently lowered the estimated grating acuity. Two domestic cats previously trained on a two-choice visual discrimination task were retrained on a grating detection/discrimination task with unlimited time, high luminance, high contrast targets, and adequate space to prevent poor accommodation from affecting the results. Initially, vertical gratings of increasing cpd were tested until failure. Then, horizontal gratings of increasing cpd were tested until failure. Finally, the finest horizontal grating resolved was confirmed with a third test requiring 24 correct out of 36 consecutive trials, yielding a binomial probability less than 0.02 of non-random occurrence. M1, a 7-year-old male gray tabby with +2.00 OU refraction, tested for a grating detection acuity of 15 cpd for both vertical and horizontal gratings (binomial probability = 0.009). F1, a 2-year-old female gray tabby with +0.25 OU refraction, tested for a grating orientation discrimination acuity of 20 cpd for both vertical and horizontal gratings (binomial probability = 0.004). These results demonstrate that a young cat with good focus is capable of discriminating 20 cpd, in close agreement with the physiologic maximum. Uncorrected focusing errors appear to degrade visual performance. Optimum experimental conditions resulted in better grating acuity measurements than previously reported, emphasizing the importance of environmental factors in feline behavioral testing.

  8. Characteristics of Fixational Eye Movements in Amblyopia: Limitations on Fixation Stability and Acuity?

    PubMed Central

    Kumar, Girish; Li, Roger W.; Levi, Dennis M.

    2015-01-01

    Persons with amblyopia, especially those with strabismus, are known to exhibit abnormal fixational eye movements. In this paper, we compared six characteristics of fixational eye movements among normal control eyes (n=16), the non-amblyopic fellow eyes and the amblyopic eyes of anisometropic (n=14) and strabismic amblyopes (n=14). These characteristics include the frequency, magnitude of landing errors, amplitude and speed of microsaccades, and the amplitude and speed of slow drifts. Fixational eye movements were recorded using retinal imaging while observers monocularly fixated a 1° cross. Eye position data were recovered using a cross-correlation procedure. We found that in general, the characteristics of fixational eye movements are not significantly different between the fellow eyes of amblyopes and controls, and that the strabismic amblyopic eyes are always different from the other groups. Next, we determined the primary factors that limit fixation stability and visual acuity in amblyopic eyes by examining the relative importance of the different oculomotor characteristics, adding acuity (for fixation stability) or fixation stability (for acuity), and the type of amblyopia, as predictive factors in a multiple linear regression model. We show for the first time that the error magnitude of microsaccades, acuity, amplitude and frequency of microsaccades are primary factors limiting fixation stability; while the error magnitude, fixation stability, amplitude of drifts and amplitude of microsaccades are the primary factors limiting acuity. A mediation analysis showed that the effects of error magnitude and amplitude of microsaccades on acuity could be explained, at least in part, by their effects on fixation stability. PMID:25668775

  9. Vestibular, Visual Acuity and Balance Outcomes in Children with Cochlear Implants: A Preliminary Report

    PubMed Central

    Janky, Kristen; Givens, Diane

    2016-01-01

    There is a high incidence of vestibular loss in children with cochlear implants (CCI). However, the relationship between vestibular loss and various outcomes is unknown in children. Objectives 1) determine if age-related changes in peripheral vestibular tests occur; 2) quantify peripheral vestibular function in children with normal hearing (CNH) and CCI; 3) determine if amount of vestibular loss predicts visual acuity and balance performance. Design Eleven CCI and 12 CNH completed the following tests of vestibular function: ocular and cervical vestibular evoked myogenic potential (VEMP) to assess utricle and saccule function, and the video head impulse test (vHIT) to assess semicircular canal function. The relationship between amount of vestibular loss and the following balance and visual acuity outcomes was assessed: dynamic gait index, single leg stance, the sensory organization test, and tests of visual acuity, including dynamic visual acuity and the gaze stabilization test. Results 1) There were no significant age-related changes in peripheral vestibular testing with the exception of the n23 cervical VEMP latency, which was moderately correlated with age; 2) CCI had significantly higher rates of vestibular loss for each test of canal and otolith function; 3) Amount of vestibular loss predicted performance on single leg stance, the dynamic gait index, some conditions of the sensory organization test, and the dynamic visual acuity test. Age was also a contributing factor for predicting the performance of almost all outcomes. Conclusions Preliminarily, children with vestibular loss do not recover naturally to levels of their healthy peers, particularly with activities that utilize vestibular input; they have poorer visual acuity and balance function. PMID:26182202

  10. Tactile acuity training for patients with chronic low back pain: a pilot randomised controlled trial

    PubMed Central

    2014-01-01

    Background Chronic pain can disrupt the cortical representation of a painful body part. This disruption may play a role in maintaining the individual’s pain. Tactile acuity training has been used to normalise cortical representation and reduce pain in certain pain conditions. However, there is little evidence for the effectiveness of this intervention for chronic low back pain (CLBP). The primary aim of this study was to inform the development of a fully powered randomised controlled trial (RCT) by providing preliminary data on the effect of tactile acuity training on pain and function in individuals with CLBP. The secondary aim was to obtain qualitative feedback about the intervention. Methods In this mixed-methods pilot RCT 15 individuals were randomised to either an intervention (tactile acuity training) or a placebo group (sham tactile acuity training). All participants received 3 sessions of acuity training (intervention or sham) from a physiotherapist and were requested to undertake daily acuity home training facilitated by an informal carer (friend/relative). All participants also received usual care physiotherapy. The primary outcome measures were pain (0-100visual analogue scale (VAS)) and function (Roland Morris Disability Questionnaire (RMDQ)). Participants and their informal carers were invited to a focus group to provide feedback on the intervention. Results The placebo group improved by the greatest magnitude for both outcome measures, but there was no statistically significant difference (Mean difference (95%CI), p-value) between groups for change in pain (25.6 (-0.7 to 51.9), p = 0.056) or function (2.2 (-1.6 to 6.0), p = 0.237). Comparing the number of individuals achieving a minimally clinically significant improvement, the placebo group had better outcomes for pain with all participants achieving ≥30% improvement compared to only a third of the intervention group (6/6 vs. 3/9, p = 0.036). Qualitatively, participants reported that

  11. Posterior staphyloma in oculocutaneous albinism: another possible cause of reduced visual acuity.

    PubMed

    Lee, Susan; Schimmenti, Lisa A; King, Richard A; Brilliant, Murray; Anderson, Jennifer L; Schoonveld, Cheri; Summers, C Gail

    2015-12-01

    Posterior staphyloma is typically associated with myopic degeneration and has not been recognized as a cause of reduced visual acuity in albinism. We report 3 cases of posterior staphyloma, each with oculocutaneous albinism (OCA) defined by phenotype and genotype. Two cases are biological sisters with OCA type 2; one was myopic and the other was hyperopic. The third case involves a man with OCA associated with Hermansky-Pudlak syndrome (HPS-5). Staphyloma may be another cause of reduced visual acuity in albinism, particularly with increasing age. It may occur in association with myopia or hyperopia.

  12. Preserved functional and structural integrity of the papillomacular area correlates with better visual acuity in retinitis pigmentosa.

    PubMed

    Konieczka, K; Bojinova, R I; Valmaggia, C; Schorderet, D F; Todorova, M G

    2016-10-01

    PurposeLinking multifocal electroretinography (mfERG) and optical coherence tomography (OCT) findings with visual acuity in retinitis pigmentosa (RP) patients.DesignProspective, cross-sectional, nonintervention study.SubjectsPatients with typical RP and age-matched controls, who underwent SD-OCT (spectral domain OCT) and mfERG, were included.MethodsMfERG responses were averaged in three zones (zone 1 (0°-3°), zone 2 (3°-8°), and zone 3 (8°-15°)). Baseline-to-trough- (N1) and trough-to-peak amplitudes (N1P1) of the mfERG were compared with corresponding areas of the OCT. The papillomacular area (PMA) was analyzed separately. Correlations between best-corrected visual acuity (BCVA, logMAR) and each parameter were determined.Main outcome measuresComparing structural (OCT) and functional (mfERG) measures with the BCVA.ResultsIn RP patients, the N1 and N1P1 responses showed positive association with the central retinal thickness outside zone 1 (P≤0.002), while the central N1 and the N1P1 responses in zones 1, 2, and 3-with the BCVA (P≤0.007). The integrity of the IS/OS line on OCT showed also a positive association with the BCVA (P<0.001). Isolated analysis of the PMA strengthened further the structure-function association with the BCVA (P≤0.037). Interactions between the BCVA and the OCT, respectively, the mfERG parameters were more pronounced in the RP subgroup without macular edema (P≤0.020).ConclusionIn RP patients, preserved structure-function of PMA, measured by mfERG amplitude and OCT retinal thickness, correlated well with the remaining BCVA. The subgroup analyses revealed stronger links between the examined parameters, in the RP subgroup without appearance of macular edema.

  13. Unchanged content of oxidative enzymes in fast-twitch muscle fibers and kinetics after intensified training in trained cyclists

    PubMed Central

    Christensen, Peter M; Gunnarsson, Thomas P; Thomassen, Martin; Wilkerson, Daryl P; Nielsen, Jens Jung; Bangsbo, Jens

    2015-01-01

    The present study examined if high intensity training (HIT) could increase the expression of oxidative enzymes in fast-twitch muscle fibers causing a faster oxygen uptake () response during intense (INT), but not moderate (MOD), exercise and reduce the slow component and muscle metabolic perturbation during INT. Pulmonary kinetics was determined in eight trained male cyclists (-max: 59 ± 4 (means ± SD) mL min−1 kg−1) during MOD (205 ± 12 W ∼65% -max) and INT (286 ± 17 W ∼85% -max) exercise before and after a 7-week HIT period (30-sec sprints and 4-min intervals) with a 50% reduction in volume. Both before and after HIT the content in fast-twitch fibers of CS (P < 0.05) and COX-4 (P < 0.01) was lower, whereas PFK was higher (P < 0.001) than in slow-twitch fibers. Content of CS, COX-4, and PFK in homogenate and fast-twitch fibers was unchanged with HIT. Maximal activity (μmol g DW−1 min−1) of CS (56 ± 8 post-HIT vs. 59 ± 10 pre-HIT), HAD (27 ± 6 vs. 29 ± 3) and PFK (340 ± 69 vs. 318 ± 105) and the capillary to fiber ratio (2.30 ± 0.16 vs. 2.38 ± 0.20) was unaltered following HIT. kinetics was unchanged with HIT and the speed of the primary response did not differ between MOD and INT. Muscle creatine phosphate was lower (42 ± 15 vs. 66 ± 17 mmol kg DW−1) and muscle lactate was higher (40 ± 18 vs. 14 ± 5 mmol kg DW−1) at 6 min of INT (P < 0.05) after compared to before HIT. A period of intensified training with a volume reduction did not increase the content of oxidative enzymes in fast-twitch fibers, and did not change kinetics. PMID:26152692

  14. Unchanged peripheral sympathetic activity following withdrawal of chronic metoprolol treatment. A study of noradrenaline concentrations and kinetics in plasma.

    PubMed Central

    Olsson, G; Daleskog, M; Hjemdahl, P; Rehnqvist, N

    1984-01-01

    Noradrenaline plasma kinetics were assessed in 17 male patients, who had been treated with metoprolol 100-200 mg daily (n = 8) or placebo for 3 years after an acute myocardial infarction, before and 1 week after gradual withdrawal (during 1 week) of the study treatment. Endogenous noradrenaline concentrations in plasma were measured by high performance liquid chromatography. Noradrenaline spillover rate, plasma clearance and the t1/2 for the rapid removal from plasma were determined by radio-tracer methodology. During treatment the plasma noradrenaline concentrations and noradrenaline plasma kinetic variables were similar in the two groups. Venous plasma noradrenaline concentrations were more closely correlated to the spillover rates of noradrenaline to plasma than to the clearance of noradrenaline from plasma, but the spillover rates were correlated to the clearance rates. Following the withdrawal of metoprolol noradrenaline clearance from plasma increased slightly (by 18 +/- 5%, P less than 0.05), but the plasma concentrations and spillover rates of noradrenaline were unchanged. In the placebo group withdrawal did not result in any significant changes. Our results indicate that a generalised increase in sympathetic nerve activity is not the cause of so-called rebound phenomena following withdrawal of chronic beta-adrenoceptor blockade. PMID:6487497

  15. Ambient aerosols remain highly acidic despite dramatic sulfate reductions

    NASA Astrophysics Data System (ADS)

    Nenes, Athanasios; Weber, Rodney; Guo, Hongyu; Russell, Armistead

    2016-04-01

    The pH of fine particles has many vital environmental impacts. By affecting aerosol concentrations, chemical composition and toxicity, particle pH is linked to regional air quality and climate, and adverse effects on human health. Sulfate is often the main acid component that drives pH of fine particles (i.e., PM2.5) and is neutralized to varying degrees by gas phase ammonia. Sulfate levels have decreased by approximately 70% over the Southeastern United States in the last fifteen years, but measured ammonia levels have been fairly steady implying the aerosol may becoming more neutral. Using a chemically comprehensive data set, combined with a thermodynamic analysis, we show that PM2.5 in the Southeastern U.S. is highly acidic (pH between 0 and 2), and that pH has remained relatively unchanged throughout the past decade and a half of decreasing sulfate. Even with further sulfate reductions, pH buffering by gas-particle partitioning of ammonia is expected to continue until sulfate drops to near background levels, indicating that fine particle pH will remain near current levels into the future. These results are non-intuitive and reshape expectations of how sulfur emission reductions impact air quality in the Southeastern U.S. and possibly other regions across the globe.

  16. Developmental trajectory of number acuity reveals a severe impairment in developmental dyscalculia.

    PubMed

    Piazza, Manuela; Facoetti, Andrea; Trussardi, Anna Noemi; Berteletti, Ilaria; Conte, Stefano; Lucangeli, Daniela; Dehaene, Stanislas; Zorzi, Marco

    2010-07-01

    Developmental dyscalculia is a learning disability that affects the acquisition of knowledge about numbers and arithmetic. It is widely assumed that numeracy is rooted on the "number sense", a core ability to grasp numerical quantities that humans share with other animals and deploy spontaneously at birth. To probe the links between number sense and dyscalculia, we used a psychophysical test to measure the Weber fraction for the numerosity of sets of dots, hereafter called number acuity. We show that number acuity improves with age in typically developing children. In dyscalculics, numerical acuity is severely impaired, with 10-year-old dyscalculics scoring at the level of 5-year-old normally developing children. Moreover, the severity of the number acuity impairment predicts the defective performance on tasks involving the manipulation of symbolic numbers. These results establish for the first time a clear association between dyscalculia and impaired "number sense", and they may open up new horizons for the early diagnosis and rehabilitation of mathematical learning deficits.

  17. Sound Localization Acuity in Very Young Infants: An Observer-Based Testing Procedure.

    ERIC Educational Resources Information Center

    Morrongiello, Barbara A.; And Others

    1990-01-01

    Infants of 8-28 weeks were tested to determine the smallest sound shift off midline and along the horizontal axis that the infants could reliably discriminate. Results indicated localization acuity increased with age. Video records revealed numerous auditory orienting behaviors with methodological implications. (RH)

  18. The Effect of Movement-Based Training upon the Aural Acuity of Conductors.

    ERIC Educational Resources Information Center

    Hayslett, Dennis

    1996-01-01

    Examines the effect of physical movement on the aural acuity of conducting subjects using the the Seashore Measures of Musical Talents. Reveals that subjects who received movement training showed significantly higher gain scores than those who had not. Proposes the integration of movement-based training into the conducting curriculum. (DSK)

  19. Perceptual limit to display resolution of images as per visual acuity

    NASA Astrophysics Data System (ADS)

    Masaoka, Kenichiro; Niida, Takahiro; Murakami, Miya; Suzuki, Kenji; Sugawara, Masayuki; Nojiri, Yuji

    2008-02-01

    Achieving ultimate visual realness of natural images on a display requires high resolution, so that artifacts due to finite image resolution are undetectable. An image resolution of 30 cycles/degree (cpd) or one pixel/arc-minute is often used as the criterion for viewing conditions when assessing displayed image quality. It is reasoned that if the pixel size is smaller than the separable angle of normal vision (20/20), the pixel structure is invisible and doesn't negatively affect image quality. However, it is not clear whether 30 cpd resolution is adequate to prevent seeing artifacts, especially for observers with better than 20/20 vision. We conducted experiments to find the threshold resolution of natural images and its dependence on visual acuity. Three objects were used; each object was presented 60 times at 5 resolutions (19.5, 26, 39, 52, or 78 cpd) next to the same image at a resolution of 156 cpd. Forty-five observers with visual acuity of 20/20 or better were asked to make a forced-choice distinction between the image pair in regard to resolution. Each observer indicated which image of the pair appeared at a higher resolution. The results show that the mean resolution for 75% correct responses for each of the visual acuity groups increased from more than 30 cpd as visual acuity increased and reached a plateau at 40-50 cpd at -0.3 logMAR.

  20. Acuities for textures and gratings in kittens assessed by preferential looking.

    PubMed

    Wilkinson, F

    1995-06-01

    A forced-choice preferential looking paradigm, similar to that developed for human infants, was used to assess visual thresholds in kittens between 21 and 45 days of age. In agreement with the earlier work of Sireteanu [19,30], the technique was found to be successful for grating acuity measurement. Acuity for square wave gratings (vs. matched greys) increased from 0.12 cycles/degrees at 21 days to 1.6 cycles/degrees at 40 days of age. Comparable results were obtained at three viewing distances: 20, 40, and 60 cm, indicating that accommodation is not a limiting factor in spatial resolution over this range of distances. Kittens also showed preferences for texture arrays with strong oriented components and 'texture acuities' were found to be comparable to acuity for square wave gratings. A consistent orientation anisotropy favouring horizontal line elements was seen in very young kittens but disappeared by 5 weeks of age. Preferences for texture arrays composed of dots were much weaker and thresholds could not be determined in all cases. The results are discussed in the context of the Banks and Ginsberg [2] model of infant preferences.

  1. Teachers' Knowledge of the Relationship of Auditory Acuity and Hearing Impairment to Reading.

    ERIC Educational Resources Information Center

    Marshall, Evelyn Myrtle

    Teacher's knowledge of the relationship of auditory acuity and hearing impairment to reading was evaluated with 60 teachers and specialists (regular classroom primary and upper elementary teachers, reading teachers, teachers of the learning disabled, teachers of the hearing impaired, and speech and language pathologists). Ss were administered a…

  2. A Close Eye on the Eagle-Eyed Visual Acuity Hypothesis of Autism

    ERIC Educational Resources Information Center

    Bolte, Sven; Schlitt, Sabine; Gapp, Volker; Hainz, Daniela; Schirman, Shella; Poustka, Fritz; Weber, Bernhard; Freitag, Christine; Ciaramidaro, Angela; Walter, Henrik

    2012-01-01

    Autism spectrum disorders (ASD) have been associated with sensory hypersensitivity. A recent study reported visual acuity (VA) in ASD in the region reported for birds of prey. The validity of the results was subsequently doubted. This study examined VA in 34 individuals with ASD, 16 with schizophrenia (SCH), and 26 typically developing (TYP).…

  3. Short-term visual deprivation, tactile acuity, and haptic solid shape discrimination.

    PubMed

    Crabtree, Charles E; Norman, J Farley

    2014-01-01

    Previous psychophysical studies have reported conflicting results concerning the effects of short-term visual deprivation upon tactile acuity. Some studies have found that 45 to 90 minutes of total light deprivation produce significant improvements in participants' tactile acuity as measured with a grating orientation discrimination task. In contrast, a single 2011 study found no such improvement while attempting to replicate these earlier findings. A primary goal of the current experiment was to resolve this discrepancy in the literature by evaluating the effects of a 90-minute period of total light deprivation upon tactile grating orientation discrimination. We also evaluated the potential effect of short-term deprivation upon haptic 3-D shape discrimination using a set of naturally-shaped solid objects. According to previous research, short-term deprivation enhances performance in a tactile 2-D shape discrimination task - perhaps a similar improvement also occurs for haptic 3-D shape discrimination. The results of the current investigation demonstrate that not only does short-term visual deprivation not enhance tactile acuity, it additionally has no effect upon haptic 3-D shape discrimination. While visual deprivation had no effect in our study, there was a significant effect of experience and learning for the grating orientation task - the participants' tactile acuity improved over time, independent of whether they had, or had not, experienced visual deprivation.

  4. The Effects of Drift and Displacement Motion on Dynamic Visual Acuity

    ERIC Educational Resources Information Center

    Aznar-Casanova, J. Antonio; Quevedo, Lluisa; Sinnett, Scott

    2005-01-01

    Dynamic Visual Acuity (DVA) can be measured from two types of equivalently considered movement referred to as drifting-motion and displacement-motion. Displacement motion can be best described as the horizontal displacement of a stimulus, thus implying pursuit eye movements, and involves moving the stimulus from the fixation point of gaze towards…

  5. Burn Patient Acuity Demographics, Scar Contractures, and Rehabilitation Treatment Time Related to Patient Outcomes (ACT)

    DTIC Science & Technology

    2014-10-01

    Scar Contractures, and Rehabilitation Treatment Time Related to Patient Outcomes, conveniently referred to as the ACT for representing Acuity...acute and intermediate phases of burn rehabilitation through the collection of daily treatment information for analysis. In particular, the ACT is...primarily interested in investigating the influence that time spent receiving rehabilitation treatments has on patient outcomes as a reflection of

  6. Binocular Visual Acuity of Children: Demographic and Socioeconomic Characteristics - United States.

    ERIC Educational Resources Information Center

    National Center for Health Statistics (DHEW/PHS), Hyattsville, MD.

    Reported were estimates of the uncorrected binocular visual acuity levels of distance and near for children aged 6 to 11 years in the noninstitutional population of the United States in relation to their demographic and socioeconomic background. A sample of 7,119 children participated in the Health Examination Survey program of 1963-65. Findings…

  7. Binocular Coordination, Acuity, and Locomotion: Interacting with Objects in the Environment.

    ERIC Educational Resources Information Center

    Knowlton, Marie; Lee, Inkyung

    1995-01-01

    This article addresses issues of orientation and mobility for students with visual impairments, including the perception of motion, visual mechanisms of binocular coordination, perception of impending collision, and body movement to avoid collision. Emphasis is on the role of binocular coordination ability and acuity. These concepts were evaluated…

  8. Visual Vestibular Interaction in the Dynamic Visual Acuity Test during Voluntary Head Rotation

    NASA Technical Reports Server (NTRS)

    Lee, Moo Hoon; Durnford, Simon; Crowley, John; Rupert, Angus

    1996-01-01

    Although intact vestibular function is essential in maintaining spatial orientation, no good screening tests of vestibular function are available to the aviation community. High frequency voluntary head rotation was selected as a vestibular stimulus to isolate the vestibulo-ocular reflex (VOR) from visual influence. A dynamic visual acuity test that incorporates voluntary head rotation was evaluated as a potential vestibular function screening tool. Twenty-seven normal subjects performed voluntary sinusoidal head rotation at frequencies from 0.7-4.0 Hz under three different visual conditions: visually-enhanced VOR, normal VOR, and visually suppressed VOR. Standardized Baily-Lovie chart letters were presented on a computer monitor in front of the subject, who then was asked to read the letters while rotating his head horizontally. The electro-oculogram and dynamic visual acuity score were recorded and analyzed. There were no significant differences in gain or phase shift among three visual conditions in the frequency range of 2.8 to 4.0 Hz. The dynamic visual acuity score shifted less than 0.3 logMAR at frequencies under 2.0 Hz. The dynamic visual acuity test at frequencies a round 2.0 Hz can be recommended for evaluating vestibular function.

  9. Evaluation of vestibular and dynamic visual acuity in adults with congenital deafness.

    PubMed

    Nakajima, Yukinori; Kaga, Kimitaka; Takekoshi, Hideki; Sakuraba, Keisyoku

    2012-10-01

    This study compared vestibular and dynamic visual acuity in 19 adult athletes with deafness participating in Deaflympics to those of 25 young adults with normal hearing. Balance capability was evaluated using a one-leg standing test with eyes open and stabilometry. Caloric tests and vestibular evoked myogenic potential tests were conducted to test vestibular function. Visual function was evaluated using a dynamic visual acuity test. No significant difference was found between results of the one-leg standing test with eyes open and stabilometry with eyes open. Athletes with deafness performed better than normal hearing young adults with eyes closed. The caloric test indicated hypofunction of the lateral semicircular canal function in 5 of the 19 athletes with deafness. Balance-function tests showed normal results for both groups. The results for athletes with deafness on visual acuity were better than those of controls. Young Deaflympics athletes with deafness can adjust their balance function as well as or better than normal hearing young adults using dynamic visual acuity.

  10. Impacting patient outcomes through design: acuity adaptable care/universal room design.

    PubMed

    Brown, Katherine Kay; Gallant, Dennis

    2006-01-01

    To succeed in today's challenging healthcare environment, hospitals must examine their impact on customers--patients and families--staff and physicians. By using competitive facility design and incorporating evidence-based concepts such as the acuity adaptable care delivery model and the universal room, the hospital will realize an impact on patient satisfaction that will enhance market share, on physician satisfaction that will foster loyalty, and on staff satisfaction that will decrease turnover. At the same time, clinical outcomes such as a reduction in mortality and complications and efficiencies such as a reduction in length of stay and minimization of hospital costs through the elimination of transfers can be gained. The results achieved are dependent on the principles used in designing the patient room that should focus on maximizing patient safety and improving healing. This article will review key design elements that support the success of an acuity adaptable unit such as the use of a private room with zones dedicated to patients, families, and staff, healing environment, technology, and decentralized nursing stations that support the success of the acuity adaptable unit. Outcomes of institutions currently utilizing the acuity adaptable concept will be reviewed.

  11. Depressive Styles and Social Acuity: Further Evidence for Distinct Interpersonal Correlates of Dependency and Self-Criticism.

    ERIC Educational Resources Information Center

    Aube, Jennifer; Whiffen, Valerie E.

    1996-01-01

    Examines whether dependency and self-criticism (personality types linked with depression) are related to social acuity. Uses 90 university students who completed 2 measures of social acuity. Finds that self-critical persons were significantly less accurate on both tasks, even when controlling for depressive symptomatology. Supports previous…

  12. Reduction in Dynamic Visual Acuity Reveals Gaze Control Changes Following Spaceflight

    NASA Technical Reports Server (NTRS)

    Peters, Brian T.; Brady, Rachel A.; Miller, Chris; Lawrence, Emily L.; Mulavara Ajitkumar P.; Bloomberg, Jacob J.

    2010-01-01

    INTRODUCTION: Exposure to microgravity causes adaptive changes in eye-head coordination that can lead to altered gaze control. This could affect postflight visual acuity during head and body motion. The goal of this study was to characterize changes in dynamic visual acuity after long-duration spaceflight. METHODS: Dynamic Visual Acuity (DVA) data from 14 astro/cosmonauts were collected after long-duration (6 months) spaceflight. The difference in acuity between seated and walking conditions provided a metric of change in the subjects ability to maintain gaze fixation during self-motion. In each condition, a psychophysical threshold detection algorithm was used to display Landolt ring optotypes at a size that was near each subject s acuity threshold. Verbal responses regarding the orientation of the gap were recorded as the optotypes appeared sequentially on a computer display 4 meters away. During the walking trials, subjects walked at 6.4 km/h on a motorized treadmill. RESULTS: A decrement in mean postflight DVA was found, with mean values returning to baseline within 1 week. The population mean showed a consistent improvement in DVA performance, but it was accompanied by high variability. A closer examination of the individual subject s recovery curves revealed that many did not follow a pattern of continuous improvement with each passing day. When adjusted on the basis of previous long-duration flight experience, the population mean shows a "bounce" in the re-adaptation curve. CONCLUSION: Gaze control during self-motion is altered following long-duration spaceflight and changes in postflight DVA performance indicate that vestibular re-adaptation may be more complex than a gradual return to normal.

  13. A Systematic Investigation of Accuracy and Response Time Based Measures Used to Index ANS Acuity

    PubMed Central

    Dietrich, Julia Felicitas; Huber, Stefan; Klein, Elise; Willmes, Klaus; Pixner, Silvia; Moeller, Korbinian

    2016-01-01

    The approximate number system (ANS) was proposed to be a building block for later mathematical abilities. Several measures have been used interchangeably to assess ANS acuity. Some of these measures were based on accuracy data, whereas others relied on response time (RT) data or combined accuracy and RT data. Previous studies challenged the view that all these measures can be used interchangeably, because low correlations between some of the measures had been observed. These low correlations might be due to poor reliability of some of the measures, since the majority of these measures are mathematically related. Here we systematically investigated the relationship between common ANS measures while avoiding the potential confound of poor reliability. Our first experiment revealed high correlations between all accuracy based measures supporting the assumption that all of them can be used interchangeably. In contrast, not all RT based measures were highly correlated. Additionally, our results revealed a speed-accuracy trade-off. Thus, accuracy and RT based measures provided conflicting conclusions regarding ANS acuity. Therefore, we investigated in two further experiments which type of measure (accuracy or RT) is more informative about the underlying ANS acuity, depending on participants’ preferences for accuracy or speed. To this end, we manipulated participants’ preferences for accuracy or speed both explicitly using different task instructions and implicitly varying presentation duration. Accuracy based measures were more informative about the underlying ANS acuity than RT based measures. Moreover, the influence of the underlying representations on accuracy data was more pronounced when participants preferred accuracy over speed after the accuracy instruction as well as for long or unlimited presentation durations. Implications regarding the diffusion model as a theoretical framework of dot comparison as well as regarding the relationship between ANS acuity and

  14. Foveal photoreceptor explanation of short-term visual acuity recovery associated with laser-induced foveal damage

    NASA Astrophysics Data System (ADS)

    Langus, Amir; Zwick, Harry; Stuck, Bruce E.; Belkin, Michael

    2003-06-01

    Both human laser accident cases and non-human primate behavioral studies demonstrate the possibility of full visual acuity recovery following foveal laser injury. Current explanations of such recovery require suppositions of complex retinal reorganization dynamics or neural reorganization at higher order visual brain systems. However, recent investigation based on data of retinal photoreceptor and ganglion cell topography and connectivity, suggest that the amount of static inherent plasticity, already exists at the retinal level, may also explain visual acuity recovery in the presence of laser-induced foveal damage. Modeling the off-axis visual acuity while utilizing this data, produces a more gradual fall-off in visual acuity, and supports the notion that visual acuity recovery may reside in the topographical organization of the cones. Moreover, considering the filling-in phenomena, which can conceal the presence of retinal damage from being recognized, together with eye movements, could nullify scotoma, as long as the retinal damage is not too extensive.

  15. Where do those remains come from?

    PubMed

    Nociarová, Dominika; Adserias, M Jose; Malgosa, Assumpció; Galtés, Ignasi

    2014-12-01

    Part of the study of skeletal remains or corpses in advance decay located in the field involves determining their origin. They may be the result of criminal activity, accident, unearthed because of erosion, or they may also have originated from a cemetery. The discovery site, condition of the remains, and the associated artifacts, are factors that could be helpful for the forensic anthropologist to identify the origin of the remains. In order to contribute to this recognition, an analysis was made of the exhumations of 168 unclaimed human remains from the cemetery of Terrassa (Catalonia, Spain). This investigation presents a description of artifacts and conditions of remains that could indicate that the human remains may have originated from a cemetery.

  16. Dynamic Visual Acuity and Landing Sickness in Crewmembers Returning from Long-Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Rosenberg, M.J.F; Peters, B.T.; Reschke, M. F.

    2016-01-01

    Long-term exposure to microgravity causes sensorimotor adaptations that result in functional deficits upon returning to a gravitational environment. At landing the vestibular system and the central nervous system, responsible for coordinating head and eye movements, are adapted to microgravity and must re-adapt to the gravitational environment. This re-adaptation causes decrements in gaze control and dynamic visual acuity, with astronauts reporting oscillopsia and blurred vision. Dynamic visual acuity (DVA) is assessed using an oscillating chair developed in the Neuroscience Laboratory at JSC. This chair is lightweight and easily portable for quick deployment in the field. The base of the chair is spring-loaded and allows for manual oscillation of the subject. Using a metronome, the chair is vertically oscillated plus or minus 2 cm at 2 Hz by an operator, to simulate walking. While the subject is being oscillated, they are asked to discern the direction of Landolt-C optotypes of varying sizes and record their direction using a gamepad. The visual acuity thresholds are determined using an algorithm that alters the size of the optotype based on the previous response of the subject using a forced-choice best parameter estimation that is able to rapidly converge on the threshold value. Visual acuity thresholds were determined both for static (seated) and dynamic (oscillating) conditions. Dynamic visual acuity is defined as the difference between the dynamic and static conditions. Dynamic visual acuity measures will be taken prior to flight (typically L-180, L-90, and L-60) and up to eight times after landing, including up to 3 times on R plus 0. Follow up measurements will be taken at R plus 1 (approximately 36 hours after landing). Long-duration International Space Station crewmembers will be tested once at the refueling stop in Europe and once again upon return to Johnson Space Center. In addition to DVA, subjective ratings of motion sickness will be recorded

  17. Changes in smell acuity induced by radiation exposure of the olfactory mucosa

    SciTech Connect

    Ophir, D.; Guterman, A.; Gross-Isseroff, R.

    1988-08-01

    The effects of ionizing radiation on smell acuity were assessed in 12 patients in whom the olfactory mucosa was exposed to radiation in the course of treatment for nasopharyngeal carcinoma or pituitary adenoma. Olfactory detection thresholds for two odorants (amyl acetate and eugenol) were determined before the start of radiation therapy, within a week of termination of therapy, and 1, 3, and 6 months later. The results show clearly that smell acuity is profoundly affected by therapeutic irradiation. Thresholds had increased in all 12 patients by the end of treatment and were still high one month later. Varying degrees of recovery were noted in most patients three to six months after cessation of treatment. The fate of the sense of smell deserves more attention when considering the disability caused by irradiation to certain head and neck tumors.

  18. Antihistamines and visual function: studies on dynamic acuity and the pupillary response to light.

    PubMed Central

    Nicholson, A N; Smith, P A; Spencer, M B

    1982-01-01

    1 Effects of three antihistamines, triprolidine (10 mg) in a sustained release form, astemizole (10 mg) and terfenadine (60 mg), have been studied on dynamic visual acuity and on the response of the pupil to light, together with critical flicker fusion, digit symbol substitution and cancellation, and subjective assessment of mood. The study was double-blind and effects were observed from 0.5-4.0 h after ingestion. 2 Triprolidine impaired dynamic acuity and reduced the threshold for subjective fusion of a flickering light, but there were no changes with astemizole or terfenadine. The diameter of the pupil and its response to light were not changed by the drugs. 3 Performance on digit symbol substitution and cancellation was not altered by the drugs. 4 Astemizole and terfenadine are promising antihistamines for those involved in skilled activity. PMID:6128019

  19. Focus adjustment effects on visual acuity and oculomotor balance with aviator night vision displays.

    PubMed

    Kotulak, J C; Morse, S E

    1994-04-01

    Sixteen U.S. Army aviators, who were given training on focus adjustment technique with aviator night vision goggles (NVG), showed an improvement in visual acuity with focus adjustment compared to a fixed infinity focus control. The long-term effect of focus adjustment on vision was not measured; however, adjustment accuracy was found to be generally within acceptable limits based on computer modeling and available physiologic data. Fixed focus eyepieces that are set to a low minus power may partially compensate for instrument myopia, but they may not optimize visual acuity to the extent that adjustable focus eyepieces do. Eyepiece adjustment proficiency with present night vision devices can be improved through training that emphasizes focusing to the least possible minus dioptric power. Future night vision displays can minimize focus misadjustment by providing a tactile zero marking, a limited dioptric adjustment range, and a focusing knob capable of finer adjustment than is available with current NVG's.

  20. Modulation transfer function as a predictor of visual acuity using a night vision device

    NASA Astrophysics Data System (ADS)

    Fullenkamp, S. C.; Trissell, T. L.; Aleva, D. L.; Dixon, S.; Task, H. L.

    2005-05-01

    Night Vision Goggles (NVGs) are being used increasingly by the military and law enforcement agencies for night operations. One critical issue in assessing the utility of an NVG is its resolving power or capability to make fine detail distinguishable. The resolution of Night Vision Goggles is typically assessed by measuring the visual acuity of an operator looking through the goggles. These methods can be time consuming. Further, inconsistencies associated with visual observations and judgement add to the variance associated with these measurements. NVG Modulation Transfer Function (MTF) was explored as a possible means of characterizing NVG image quality independent of a human observer. MTF maps the potential contrast output of the NVGs as a function of spatial frequency. The results of this MTF measurement were compared with a commonly used method of visual acuity assessment.

  1. Psychophysical Test of Contrast Acuity to Aid Operational Effectiveness of Aircrew Laser Eye Protection (LEP)

    DTIC Science & Technology

    2005-08-01

    Hoffman, 1997; Bach , 2003). Due to the physical constraints of the CRT and LCD displays, it is to be expected that acuity for the cardinal...36.074 39.10 0.94 996 39 ND40AR 38.605 0.322 0.327 0.351 36.621 40.60 0.43 996 40 ND50BL 50% 48.533 0.324 0.328 0.349 45.570 50.70 0.11 99.8 49 ND50BR...Directorate and the extraordinary technical support of AFRL/HEDO. 38 References Bach , M. (2002). The Freiburg visual acuity test: measurement of the

  2. Reduced sampling efficiency causes degraded Vernier hyperacuity with normal aging: Vernier acuity in position noise.

    PubMed

    Li, Roger W; Brown, Brian; Edwards, Marion H; Ngo, Charlie V; Chat, Sandy W; Levi, Dennis M

    2012-01-01

    Vernier acuity, a form of visual hyperacuity, is amongst the most precise forms of spatial vision. Under optimal conditions Vernier thresholds are much finer than the inter-photoreceptor distance. Achievement of such high precision is based substantially on cortical computations, most likely in the primary visual cortex. Using stimuli with added positional noise, we show that Vernier processing is reduced with advancing age across a wide range of noise levels. Using an ideal observer model, we are able to characterize the mechanisms underlying age-related loss, and show that the reduction in Vernier acuity can be mainly attributed to the reduction in efficiency of sampling, with no significant change in the level of internal position noise, or spatial distortion, in the visual system.

  3. Gains following perceptual learning are closely linked to the initial visual acuity.

    PubMed

    Yehezkel, Oren; Sterkin, Anna; Lev, Maria; Levi, Dennis M; Polat, Uri

    2016-04-28

    The goal of the present study was to evaluate the dependence of perceptual learning gains on initial visual acuity (VA), in a large sample of subjects with a wide range of VAs. A large sample of normally sighted and presbyopic subjects (N = 119; aged 40 to 63) with a wide range of uncorrected near visual acuities (VA, -0.12 to 0.8 LogMAR), underwent perceptual learning. Training consisted of detecting briefly presented Gabor stimuli under spatial and temporal masking conditions. Consistent with previous findings, perceptual learning induced a significant improvement in near VA and reading speed under conditions of limited exposure duration. Our results show that the improvements in VA and reading speed observed following perceptual learning are closely linked to the initial VA, with only a minor fraction of the observed improvement that may be attributed to the additional sessions performed by those with the worse VA.

  4. Retail Clinic Visits For Low-Acuity Conditions Increase Utilization And Spending.

    PubMed

    Ashwood, J Scott; Gaynor, Martin; Setodji, Claude M; Reid, Rachel O; Weber, Ellerie; Mehrotra, Ateev

    2016-03-01

    Retail clinics have been viewed by policy makers and insurers as a mechanism to decrease health care spending, by substituting less expensive clinic visits for more expensive emergency department or physician office visits. However, retail clinics may actually increase spending if they drive new health care utilization. To assess whether retail clinic visits represent new utilization or a substitute for more expensive care, we used insurance claims data from Aetna for the period 2010-12 to track utilization and spending for eleven low-acuity conditions. We found that 58 percent of retail clinic visits for low-acuity conditions represented new utilization and that retail clinic use was associated with a modest increase in spending, of $14 per person per year. These findings do not support the idea that retail clinics decrease health care spending.

  5. Microactuator production via high aspect ratio, high edge acuity metal fabrication technology

    NASA Technical Reports Server (NTRS)

    Guckel, H.; Christenson, T. R.

    1993-01-01

    LIGA is a procession sequence which uses x-ray lithography on photoresist layers of several hundred micrometers to produce very high edge acuity photopolymer molds. These plastic molds can be converted to metal molds via electroplating of many different metals and alloys. The end results are high edge acuity metal parts with large structural heights. The LIGA process as originally described by W. Ehrfeld can be extended by adding a surface micromachining phase to produce precision metal parts which can be assembled to form three-dimensional micromechanisms. This process, SLIGA, has been used to fabricate a dynamometer on a chip. The instrument has been fully implemented and will be applied to tribology issues, speed-torque characterization of planar magnetic micromotors and a new family of sensors.

  6. Gains following perceptual learning are closely linked to the initial visual acuity

    PubMed Central

    Yehezkel, Oren; Sterkin, Anna; Lev, Maria; Levi, Dennis M.; Polat, Uri

    2016-01-01

    The goal of the present study was to evaluate the dependence of perceptual learning gains on initial visual acuity (VA), in a large sample of subjects with a wide range of VAs. A large sample of normally sighted and presbyopic subjects (N = 119; aged 40 to 63) with a wide range of uncorrected near visual acuities (VA, −0.12 to 0.8 LogMAR), underwent perceptual learning. Training consisted of detecting briefly presented Gabor stimuli under spatial and temporal masking conditions. Consistent with previous findings, perceptual learning induced a significant improvement in near VA and reading speed under conditions of limited exposure duration. Our results show that the improvements in VA and reading speed observed following perceptual learning are closely linked to the initial VA, with only a minor fraction of the observed improvement that may be attributed to the additional sessions performed by those with the worse VA. PMID:27122254

  7. Evaluation of the degree of turbidity of cataract lens and its correlation with retinal visual acuity

    NASA Astrophysics Data System (ADS)

    Akchurin, Garif G.; Bakutkin, Valery V.; Zimnyakov, Dmitry A.; Radchenko, Elena Y.; Tuchin, Valery V.; Akchurin, Alexander G.

    1999-06-01

    Experimental in vitro studies of speckle-modulated laser field arising after transmission through different type of human cataractous lenses are presented. Computer analysis of digital imaging has allowed to determinate the degree of destruction of spatial coherence scattered laser beam and the angle of resolution of the retina using Retinal Analyzer of Vision (AROL-1) in diagnosis of cataract. Measurement of retinal visual acuity (RVA) in 135 patient with different types of cataract (senile, complicated, posterior capsular) before and after cataract extraction and also in vitro measurement of RVA with extracted cataractal lenses has shown that laser retinometer can be used for evaluating visual acuity within 0.3 - 1, practically for all types of cataracts.

  8. Theoretical and applied aspects of night vision goggle resolution and visual acuity assessment

    NASA Astrophysics Data System (ADS)

    Task, H. Lee; Pinkus, Alan R.

    2007-04-01

    The image quality of night vision goggles is often expressed in terms of visual acuity, resolution or modulation transfer function. The primary reason for providing a measure of image quality is the underlying assumption that the image quality metric correlates with the level of visual performance that one could expect when using the device, for example, target detection or target recognition performance. This paper provides a theoretical analysis of the relationships between these three image quality metrics: visual acuity, resolution and modulation transfer function. Results from laboratory and field studies were used to relate these metrics to visual performance. These results can also be applied to non-image intensifier based imaging systems such as a helmet-mounted display coupled to an imaging sensor.

  9. Measurement of night vision goggle (NVG) visual acuity with the NVG resolution chart.

    PubMed

    DeVilbiss, C A; Antonio, J C

    1994-09-01

    Night vision goggles (NVG) operations are characterized as stressful with high task loading. Any reduction in goggle or visual performance which goes undetected can have a serious effect on flight safety and operational capability. The NVG Test Lane, with its resolution chart, provides an effective cost-efficient method for aircrew members to quickly evaluate the correct positioning and focusing of their NVG's prior to each mission. This evaluation validated the ability of the NVG resolution chart to produce the same performance results as a more detailed psychophysical procedure. NVG visual acuity was measured for five subjects (four pilots and one non-pilot) with two different night vision goggles. The results supported that there is no statistical difference between the results obtained with the individual target format and the 3 x 3 format. Additionally, the pilots with current NVG experience were able to obtain a significantly better acuity level than were those without current NVG experience.

  10. Relationship between Optical Coherence Tomography Retinal Parameters and Visual Acuity in Neovascular Age-Related Macular Degeneration

    PubMed Central

    Keane, Pearse A.; Liakopoulos, Sandra; Chang, Karen T.; Wang, Mingwu; Dustin, Laurie; Walsh, Alexander C.; Sadda, Srinivas R.

    2008-01-01

    Purpose To investigate the relationship between optical coherence tomography (OCT)-derived measurements of retinal morphology and visual acuity in patients with neovascular age-related macular degeneration (AMD). Design Retrospective cross-sectional study. Participants Two hundred sixteen consecutive patients (216 eyes) newly diagnosed with neovascular AMD, who underwent StratusOCT imaging at time of diagnosis. Methods Best-corrected Snellen visual acuity was recorded for each patient. Raw exported StratusOCT images for each patient were analyzed using publicly available custom software entitled “OCTOR”, which allows precise positioning of pre-specified boundaries on individual B-scans. Thickness/volume were calculated for morphologic parameters of interest: neurosensory retina, subretinal fluid (SRF), subretinal tissue (SRT), and pigment epithelial detachment (PED). Main Outcome Measures OCT-derived measurements of retinal morphology and visual acuity. Results An increased total volume of SRT was correlated with decreased visual acuity (r=0.370, P<0.0001). Decreased visual acuity was also modestly correlated with increased thickness of the neurosensory retina at the foveal center point (r=0.245, P=0.0004). No statistically significant association was detected between visual acuity and the total volume of SRF or PED. The association between visual acuity and both the neurosensory retina and the SRT, was stronger for lesions classified as minimally classic or occult on fluorescein angiography. For occult lesions, 20% of the variation in visual acuity could be predicted by a multiple regression model that incorporated age and SRT volume; while, for minimally classic lesions, 62% of the variation in visual acuity could be predicted by a multiple regression model that incorporated age, total neurosensory retinal volume, and total SRT volume. Conclusions The presence of increased SRT thickness/volume on OCT, and to a lesser extent increased neurosensory retinal

  11. Vision-guided ocular growth in a mutant chicken model with diminished visual acuity

    PubMed Central

    Ritchey, Eric R.; Zelinka, Christopher; Tang, Junhua; Liu, Jun; Code, Kimberly A.; Petersen-Jones, Simon; Fischer, Andy J.

    2012-01-01

    Visual experience is known to guide ocular growth. We tested the hypothesis that vision-guided ocular growth is disrupted in a model system with diminished visual acuity. We examine whether ocular elongation is influenced by form-deprivation (FD) and lens-imposed defocus in the Retinopathy, Globe Enlarged (RGE) chicken. Young RGE chicks have poor visual acuity, without significant retinal pathology, resulting from a mutation in guanine nucleotide-binding protein β3 (GNB3), also known as transducin β3 or Gβ3. The mutation in GNB3 destabilizes the protein and causes a loss of Gβ3 from photoreceptors and ON-bipolar cells. (Ritchey et al. 2010)FD increased ocular elongation in RGE eyes in a manner similar to that seen in wild-type (WT) eyes. By comparison, the excessive ocular elongation that results from hyperopic defocus was increased, whereas myopic defocus failed to significantly decrease ocular elongation in RGE eyes. Brief daily periods of unrestricted vision interrupting FD prevented ocular elongation in RGE chicks in a manner similar to that seen in WT chicks. Glucagonergic amacrine cells differentially expressed the immediate early gene Egr1 in response to growth-guiding stimuli in RGE retinas, but the defocus-dependent up-regulation of Egr1 was lesser in RGE retinas compared to that of WT retinas. We conclude that high visual acuity, and the retinal signaling mediated by Gβ3, is not required for emmetropization and the excessive ocular elongation caused by FD and hyperopic defocus. However, the loss of acuity and Gβ3 from RGE retinas causes enhanced responses to hyperopic defocus and diminished responses to myopic defocus. PMID:22824538

  12. Association of Visual Acuity and Cognitive Impairment in Older Individuals: Fujiwara-kyo Eye Study.

    PubMed

    Mine, Masashi; Miyata, Kimie; Morikawa, Masayuki; Nishi, Tomo; Okamoto, Nozomi; Kawasaki, Ryo; Yamashita, Hidetoshi; Kurumatani, Norio; Ogata, Nahoko

    2016-01-01

    Both visual impairment and cognitive impairment are essential factors that determine the quality of life in the aged population. The aim of this study was to determine if a correlation existed between visual acuity and cognitive impairment in an elderly Japanese population. The Fujiwara-kyo Eye Study was a cross-sectional study of individuals aged ≥68 years who lived in Nara Prefecture of Japan. Participants underwent ophthalmological examinations and cognitive function test. A mild visual impairment was defined as having a best corrected visual acuity (BCVA) >0.2 logarithm of the minimum angle of resolution (logMAR) units in the better eye. Cognitive impairment was defined as having a Mini-Mental State Examination (MMSE) score of ≤23 points. A total to 2818 individuals completed the examinations. The mean age of the participants was 76.3 ± 4.8 years (mean ± standard deviation). The mean BCVA of the better eye was -0.02 ± 0.13 logMAR units and 6.6% subjects were classified as being mildly visually impaired. The mean MMSE score was 27.3 ± 2.3 and 5.7% subjects were classified as being cognitively impaired. The proportion of subjects with cognitive or moderate visual impairment increased with age, and there was a significant correlation between the visual acuity and MMSE score (r = -0.10, p < 0.0001). Subjects with mild visual impairments had 2.4 times higher odds of having cognitive impairment than those without visual impairment (odds ratio 2.4, 95% confidence interval, 1.5-3.8, p < 0.001) after adjusting for age, sex, and length of education. We conclude that it may be important to maintain good visual acuity to reduce the risk of having cognitive impairment.

  13. Show me the skin! Does seeing the back enhance tactile acuity at the back?

    PubMed

    Catley, Mark J; Tabor, Abby; Miegel, Rohan G; Wand, Benedict M; Spence, Charles; Moseley, G Lorimer

    2014-10-01

    A growing body of literature associates musculoskeletal disorders with cortical reorganisation. One condition in which reorganisation is established and treatments that 'train the brain' are being widely used is chronic back pain. Recent evidence suggests that treatments that involve tactile training are more effective if they incorporate multisensory mechanisms, most obviously vision. With regard to back pain however, we must first determine if tactile function is enhanced by incorporating other modalities. A series of three cross-over experiments were conducted in healthy pain-free subjects to determine whether tactile acuity is enhanced when participants can see the skin of their back during testing. An initial randomised cross-over experiment suggested tactile acuity was significantly enhanced when participants could see their backs (t(25) = -4.226, p < 0.001, r = 0.65). However, a second replication experiment was not corroborative. Both the second (F(3,66) = 1.00, p = 0.398) and third (t(9) = 0.969, p = 0.358) experiments suggested that seeing the back did not significantly affect tactile acuity, confirming that our initial results were likely due to chance. The principle that visual feedback improves tactile acuity at the hand does not apply to the back. These results strongly suggest that attempts to enhance tactile training by incorporating vision will not offer the benefit to treatment of back pain that has been observed for treatment of hand pain.

  14. Predicting individual contrast sensitivity functions from acuity and letter contrast sensitivity measurements

    PubMed Central

    Thurman, Steven M.; Davey, Pinakin Gunvant; McCray, Kaydee Lynn; Paronian, Violeta; Seitz, Aaron R.

    2016-01-01

    Contrast sensitivity (CS) is widely used as a measure of visual function in both basic research and clinical evaluation. There is conflicting evidence on the extent to which measuring the full contrast sensitivity function (CSF) offers more functionally relevant information than a single measurement from an optotype CS test, such as the Pelli–Robson chart. Here we examine the relationship between functional CSF parameters and other measures of visual function, and establish a framework for predicting individual CSFs with effectively a zero-parameter model that shifts a standard-shaped template CSF horizontally and vertically according to independent measurements of high contrast acuity and letter CS, respectively. This method was evaluated for three different CSF tests: a chart test (CSV-1000), a computerized sine-wave test (M&S Sine Test), and a recently developed adaptive test (quick CSF). Subjects were 43 individuals with healthy vision or impairment too mild to be considered low vision (acuity range of −0.3 to 0.34 logMAR). While each test demands a slightly different normative template, results show that individual subject CSFs can be predicted with roughly the same precision as test–retest repeatability, confirming that individuals predominantly differ in terms of peak CS and peak spatial frequency. In fact, these parameters were sufficiently related to empirical measurements of acuity and letter CS to permit accurate estimation of the entire CSF of any individual with a deterministic model (zero free parameters). These results demonstrate that in many cases, measuring the full CSF may provide little additional information beyond letter acuity and contrast sensitivity. PMID:28006065

  15. Reproducibility of Nigh Vision Goggle Visual Acuity Measurements Using Landolt C’s

    DTIC Science & Technology

    1999-12-08

    Task, 1979), Snellen Acuity (Bailey & Lovie, 1979; Wiley, 1989; Miller, Provines, Block & Tredici, 1984), square-wave targets (Task & Genco , 1986...the observer focused the corresponding objective lens by viewing the 3 x 3A, NVG high- contrast square-wave resolution chart (Task & Genco , 1986...for television displays. Technical Report No. AMRL-TR-79-7. NTIS: Alexandria VA. Task, H. L. and Genco , L. V. (1986). Contrast sensitivity function

  16. Final Visual Acuity Results in the Early Treatment for Retinopathy of Prematurity Study

    PubMed Central

    2014-01-01

    Objective To compare visual acuity at 6 years of age in eyes that received early treatment for high-risk prethreshold retinopathy of prematurity (ROP) with conventionally-managed eyes. Methods Infants with symmetrical, high-risk prethreshold ROP (N=317) had one eye randomized to earlier treatment at high-risk prethreshold disease and the other eye managed conventionally, treated if ROP progressed to threshold severity. For asymmetric cases (N=84), the high-risk prethreshold eye was randomized to either early treatment or conventional management. Main Outcome Measures ETDRS visual acuity measured at 6 years of age by masked testers. Retinal structure was assessed as a secondary outcome. Results Analysis of all subjects with high-risk prethreshold ROP showed no statistically significant benefit for early treatment (24.6% v. 29.0% unfavorable outcome, P=0.15). Analysis of 6-year visual acuity results according to the Type 1 and 2 clinical algorithm showed a benefit for Type 1 eyes (25.1% v. 32.8%, P=0.02) treated early, but not Type 2 eyes (23.6% v. 19.4%, P=0.37). Early treated eyes showed a significantly better structural outcome compared with conventionally managed eyes (8.9% v. 15.2% unfavorable outcome, P<0.001), with no greater risk of ocular complications. Conclusion Early treatment for Type 1 high-risk prethreshold eyes improved visual acuity outcomes at 6 years of age. Early treatment for Type 2 high-risk prethreshold eyes did not. Application to Clinical Practice Type 1 eyes, not Type 2 eyes should be treated early. These results are particularly important considering that 52 % of Type 2 high-risk prethreshold eyes underwent regression of ROP without requiring treatment. PMID:20385926

  17. Vision-guided ocular growth in a mutant chicken model with diminished visual acuity.

    PubMed

    Ritchey, Eric R; Zelinka, Christopher; Tang, Junhua; Liu, Jun; Code, Kimberly A; Petersen-Jones, Simon; Fischer, Andy J

    2012-09-01

    Visual experience is known to guide ocular growth. We tested the hypothesis that vision-guided ocular growth is disrupted in a model system with diminished visual acuity. We examine whether ocular elongation is influenced by form-deprivation (FD) and lens-imposed defocus in the Retinopathy, Globe Enlarged (RGE) chicken. Young RGE chicks have poor visual acuity, without significant retinal pathology, resulting from a mutation in guanine nucleotide-binding protein β3 (GNB3), also known as transducin β3 or Gβ3. The mutation in GNB3 destabilizes the protein and causes a loss of Gβ3 from photoreceptors and ON-bipolar cells (Ritchey et al., 2010). FD increased ocular elongation in RGE eyes in a manner similar to that seen in wild-type (WT) eyes. By comparison, the excessive ocular elongation that results from hyperopic defocus was increased, whereas myopic defocus failed to significantly decrease ocular elongation in RGE eyes. Brief daily periods of unrestricted vision interrupting FD prevented ocular elongation in RGE chicks in a manner similar to that seen in WT chicks. Glucagonergic amacrine cells differentially expressed the immediate early gene Egr1 in response to growth-guiding stimuli in RGE retinas, but the defocus-dependent up-regulation of Egr1 was lesser in RGE retinas compared to that of WT retinas. We conclude that high visual acuity, and the retinal signaling mediated by Gβ3, is not required for emmetropization and the excessive ocular elongation caused by FD and hyperopic defocus. However, the loss of acuity and Gβ3 from RGE retinas causes enhanced responses to hyperopic defocus and diminished responses to myopic defocus.

  18. Photovoltaic restoration of sight with high visual acuity in rats with retinal degeneration

    NASA Astrophysics Data System (ADS)

    Palanker, D.; Goetz, G.; Lorach, H.; Mandel, Y.; Smith, R.; Boinagrov, D.; Lei, X.; Kamins, T.; Harris, J.; Mathieson, K.; Sher, A.

    2015-03-01

    Patients with retinal degeneration lose sight due to gradual demise of photoreceptors. Electrical stimulation of the surviving retinal neurons provides an alternative route for delivery of visual information. Subretinal photovoltaic arrays with 70μm pixels were used to convert pulsed near-IR light (880-915nm) into pulsed current to stimulate the nearby inner retinal neurons. Network-mediated responses of the retinal ganglion cells (RGCs) could be modulated by pulse width (1-20ms) and peak irradiance (0.5-10 mW/mm2). Similarly to normal vision, retinal response to prosthetic stimulation exhibited flicker fusion at high frequencies, adaptation to static images, and non-linear spatial summation. Spatial resolution was assessed in-vitro and in-vivo using alternating gratings with variable stripe width, projected with rapidly pulsed illumination (20-40Hz). In-vitro, average size of the electrical receptive fields in normal retina was 248+/-59μm - similar to their visible light RF size: 249+/-44μm. RGCs responded to grating stripes down to 67μm using photovoltaic stimulation in degenerate rat retina, and 28μm with visible light in normal retina. In-vivo, visual acuity in normally-sighted controls was 29+/-5μm/stripe, vs. 63+/-4μm/stripe in rats with subretinal photovoltaic arrays, corresponding to 20/250 acuity in human eye. With the enhanced acuity provided by eye movements and perceptual learning in human patients, visual acuity might exceed the 20/200 threshold of legal blindness. Ease of implantation and tiling of these wireless arrays to cover a large visual field, combined with their high resolution opens the door to highly functional restoration of sight.

  19. [Correctly evaluate the role of visual acuity in age-related macular degeneration treatment].

    PubMed

    Zhang, Feng

    2012-02-01

    Age-related macular degeneration (AMD) is the leading cause of irreversible visual loss in aged population. As the aging of population, the prevalence of AMD increases gradually. Anti-VEGF medication intravitreal injection, which can obtain good therapeutic efficiency and is relatively safe, becomes the main therapy for neovascular AMD. However, high-frequency repeated treatment increases the intravitreal injections risk, as well as the costs. In clinical practice, to pursue the best-corrected visual acuity, high-frequency repeated injections are implemented and inflict psychological pressure and economic burden on patients. The author believes that to pursue the best corrected visual acuity is the ultimate aim but not the only one for every ophthalmologist and patient. The activity of lesions should be overall evaluated with fundus imaging technologies. Being people-oriented is the principle in clinical medicine. A treatment plan is made according to the patients' sickness and economy and to coordinate the relation between the best corrected visual acuity and the numbers of treatment. Based on the stabilized lesion, patient should be benefited at the lowest risk and cost with the best effect.

  20. Normal Visual Acuity and Electrophysiological Contrast Gain in Adults with High-Functioning Autism Spectrum Disorder

    PubMed Central

    Tebartz van Elst, Ludger; Bach, Michael; Blessing, Julia; Riedel, Andreas; Bubl, Emanuel

    2015-01-01

    A common neurodevelopmental disorder, autism spectrum disorder (ASD), is defined by specific patterns in social perception, social competence, communication, highly circumscribed interests, and a strong subjective need for behavioral routines. Furthermore, distinctive features of visual perception, such as markedly reduced eye contact and a tendency to focus more on small, visual items than on holistic perception, have long been recognized as typical ASD characteristics. Recent debate in the scientific community discusses whether the physiology of low-level visual perception might explain such higher visual abnormalities. While reports of this enhanced, “eagle-like” visual acuity contained methodological errors and could not be substantiated, several authors have reported alterations in even earlier stages of visual processing, such as contrast perception and motion perception at the occipital cortex level. Therefore, in this project, we have investigated the electrophysiology of very early visual processing by analyzing the pattern electroretinogram-based contrast gain, the background noise amplitude, and the psychophysical visual acuities of participants with high-functioning ASD and controls with equal education. Based on earlier findings, we hypothesized that alterations in early vision would be present in ASD participants. This study included 33 individuals with ASD (11 female) and 33 control individuals (12 female). The groups were matched in terms of age, gender, and education level. We found no evidence of altered electrophysiological retinal contrast processing or psychophysical measured visual acuities. There appears to be no evidence for abnormalities in retinal visual processing in ASD patients, at least with respect to contrast detection. PMID:26379525

  1. Acuity-independent effects of visual deprivation on human visual cortex.

    PubMed

    Hou, Chuan; Pettet, Mark W; Norcia, Anthony M

    2014-07-29

    Visual development depends on sensory input during an early developmental critical period. Deviation of the pointing direction of the two eyes (strabismus) or chronic optical blur (anisometropia) separately and together can disrupt the formation of normal binocular interactions and the development of spatial processing, leading to a loss of stereopsis and visual acuity known as amblyopia. To shed new light on how these two different forms of visual deprivation affect the development of visual cortex, we used event-related potentials (ERPs) to study the temporal evolution of visual responses in patients who had experienced either strabismus or anisometropia early in life. To make a specific statement about the locus of deprivation effects, we took advantage of a stimulation paradigm in which we could measure deprivation effects that arise either before or after a configuration-specific response to illusory contours (ICs). Extraction of ICs is known to first occur in extrastriate visual areas. Our ERP measurements indicate that deprivation via strabismus affects both the early part of the evoked response that occurs before ICs are formed as well as the later IC-selective response. Importantly, these effects are found in the normal-acuity nonamblyopic eyes of strabismic amblyopes and in both eyes of strabismic patients without amblyopia. The nonamblyopic eyes of anisometropic amblyopes, by contrast, are normal. Our results indicate that beyond the well-known effects of strabismus on the development of normal binocularity, it also affects the early stages of monocular feature processing in an acuity-independent fashion.

  2. Manual aiming in healthy aging: does proprioceptive acuity make the difference?

    PubMed

    Helsen, Werner F; Van Halewyck, Florian; Levin, Oron; Boisgontier, Matthieu P; Lavrysen, Ann; Elliott, Digby

    2016-04-01

    The present study examines whether non-active older adults are more dependent on visual information when executing aiming movements and whether age-related declines in proprioception play a mediating role herein. Young (N = 40) and older adults (N = 38) were divided into physically active and non-active subgroups based on self-reported sports participation levels. In experiment 1, participants executed wrist-aiming movements with and without visual feedback. In experiment 2, passive proprioceptive acuity was assessed using wrist motion detection and position matching tests. Results showed similar aiming accuracy across age groups both with and without visual feedback, but older adults exhibited longer movement times, prolonged homing-in phase, and made more corrective submovements. Passive proprioceptive acuity was significantly affected by physical activity level and age, with participants in the active group scoring better than their non-active peers. However, these declines did not predict performance changes on the aiming task. Taken together, our observations suggest that decline in proprioceptive acuity did not predict performance changes on the aiming task and older adults were able to compensate for their decreased motion and position sense when allowed sufficient time. In line with these observations, we proposed that older adults are able to compensate for their decline in proprioception by increasing their reliance on predictive models.

  3. Development and Initial Psychometric Evaluation of the Post-Acute Acuity Rating for Children

    PubMed Central

    O'Brien, Jane E.; Dumas, Helene M.

    2015-01-01

    The Post-Acute Acuity Rating for Children (PAARC) is the first known acuity rating intended to reflect medical severity based on age, reason for admission, diagnoses, dependence in activities of daily living, and technology reliance for children admitted to post-acute care rehabilitation hospitals. Content validity was tested using an expert panel scoring the Content Validity Index (CVI). Concurrent validity was examined using clinician's opinion of acuity at admission, the Complexity Index, and All Patient Refined Diagnosis Related Group (APR-DRG) codes. Predictive validity was examined with acute care readmission within 30 days. Interrater reliability was assessed using admission histories from closed cases. Content validity was established and concurrent validity was moderate to high with clinician opinion (rho = .76, p < .001), the Complexity Index (rho = .76, p < .001), and APR-DRGs (rho = .349, p = .001). Predictive validity was moderate (rho = .504, p = .005) and returns to acute care within 30 days. Interrater reliability was excellent (ICC = 0.97; 95% CI = 0.92–0.90, p < .001). Experts agreed that the PAARC's content is relevant, simple, and representative of the population. The PAARC measured well against indicators of medical complexity for pediatric outpatient care and medical record coding and was reliable between raters. This work supports proceeding with additional development and validity testing of the PAARC. PMID:26609433

  4. Is acuity enough? Other considerations in clinical investigations of visual prostheses.

    PubMed

    Lepri, Bernard P

    2009-06-01

    Visual impairing eye diseases are the major frontier facing ophthalmic research today in light of our rapidly aging population. The visual skills necessary for improving the quality of daily function and life are inextricably linked to these impairing diseases. Both research and reimbursement programs are emphasizing outcome-based results. Is improvement in visual acuity alone enough to improve the function and quality of life of visually impaired persons? This perspective summarizes the types of effectiveness endpoints for clinical investigations of visual prostheses that go beyond visual acuity. The clinical investigation of visual prostheses should include visual function, functional vision and quality of life measures. Specifically, they encompass contrast sensitivity, orientation and mobility, activities of daily living and quality of life assessments. The perspective focuses on the design of clinical trials for visual prostheses and the methods of determining effectiveness above and beyond visual acuity that will yield outcomes that are measured by improved function in the visual world and quality of life. The visually impaired population is the primary consideration in this presentation with particular emphases on retinitis pigmentosa and age-related macular degeneration. Clinical trials for visual prostheses cannot be isolated from the need for medical rehabilitation in order to obtain measurements of effectiveness that produce outcomes/evidence-based success. This approach will facilitate improvement in daily function and quality of life of patients with diseases that cause chronic vision impairment.

  5. Optical coherence tomography angiography in eyes with good visual acuity recovery after treatment for optic neuritis

    PubMed Central

    Higashiyama, Tomoaki; Nishida, Yasuhiro; Ohji, Masahito

    2017-01-01

    Objective To evaluate the retinal perfusion using optical coherence tomography (OCT) angiography in eyes with good visual acuity recovery after treatment for optic neuritis (ON). Methods Seven eyes of seven patients with good visual acuity recovery after treatment for monocular ON and seven eyes of each fellow eye used as controls were studied. Retinal perfusion around the disc and at the macula was evaluated using OCT angiography. The retinal nerve fiber layer thickness was measured around the disc. The ganglion cell layer complex thickness or the ganglion cell layer plus the inner plexiform layer thickness were measured at the macula. Results The retinal perfusions in all eyes with ON decreased around the disc and at the macula compared with those of the fellow eyes, as shown by OCT angiography (disc, P = 0.003; macula, P = 0.001). The retinal thicknesses in all eyes with ON also decreased around the disc and at the macula compared with those of the fellow eyes (disc, P < 0.001; macula, P = 0.003). Conclusions Optic neuritis may cause not only retinal structural damage but also decreased retinal perfusion, even after the visual acuity recovered well after treatment. PMID:28192497

  6. Successful Restoration of Visual Acuity with an Extended Range of Vision Intraocular Lens after Multifocal Laser Ablation.

    PubMed

    Black, Sondra

    2016-01-01

    As our baby boomer population is aging and developing cataracts, so are our post-LASIK patients. These patients underwent LASIK surgery as they wished to be spectacle-free and are hoping to remain so after intraocular lens (IOL) surgery. Unfortunately, very little information is available regarding the suitability of presbyopia correcting IOLs for post-LASIK patients. This case represents successful implantation of an extended range of vision IOL in a 59-year-old patient who underwent multifocal ablation excimer laser surgery 12 years before. Emmetropia was targeted for the dominant eye and -0.5 D for the fellow eye. The 13 month follow-up after bilateral implantation of the TECNIS Symfony IOL revealed an uncorrected visual acuity of 20/25 for distance, 20/20 for intermediate and 20/16 for near. The patient is very happy and did not report any visual symptoms when asked. This successful case should encourage surgeons to consider implanting an extended range of vision IOLs in post-LASIK patients.

  7. Successful Restoration of Visual Acuity with an Extended Range of Vision Intraocular Lens after Multifocal Laser Ablation

    PubMed Central

    Black, Sondra

    2016-01-01

    As our baby boomer population is aging and developing cataracts, so are our post-LASIK patients. These patients underwent LASIK surgery as they wished to be spectacle-free and are hoping to remain so after intraocular lens (IOL) surgery. Unfortunately, very little information is available regarding the suitability of presbyopia correcting IOLs for post-LASIK patients. This case represents successful implantation of an extended range of vision IOL in a 59-year-old patient who underwent multifocal ablation excimer laser surgery 12 years before. Emmetropia was targeted for the dominant eye and −0.5 D for the fellow eye. The 13 month follow-up after bilateral implantation of the TECNIS Symfony IOL revealed an uncorrected visual acuity of 20/25 for distance, 20/20 for intermediate and 20/16 for near. The patient is very happy and did not report any visual symptoms when asked. This successful case should encourage surgeons to consider implanting an extended range of vision IOLs in post-LASIK patients. PMID:28101037

  8. Osteological evidence for the evolution of activity pattern and visual acuity in primates.

    PubMed

    Kay, R F; Kirk, E C

    2000-10-01

    Examination of orbit size and optic foramen size in living primates reveals two adaptive phenomena. First, as noted by many authors, orbit size is strongly correlated with activity pattern. Comparisons of large samples of extant primates consistently reveal that nocturnal species exhibit proportionately larger orbits than diurnal species. Furthermore, nocturnal haplorhines (Tarsius and Aotus) have considerably larger orbits than similar-sized nocturnal strepsirrhines. Orbital hypertrophy in Tarsius and Aotus accommodates the enormously enlarged eyes of these taxa. This extreme ocular hypertrophy seen in extant nocturnal haplorhines is an adaptation for both enhanced visual acuity and sensitivity in conditions of low light intensity. Second, the relative size of the optic foramen is highly correlated with the degree of retinal summation and inferred visual acuity. Diurnal haplorhines exhibit proportionately larger optic foramina, less central retinal summation, and much higher visual acuity than do all other primates. Diurnal strepsirrhines exhibit a more subtle but significant parallel enlargement of the optic foramen and a decrease in retinal summation relative to the condition seen in nocturnal primates. These twin osteological variables of orbit size and optic foramen size may be used to draw inferences regarding the activity pattern, retinal anatomy, and visual acuity of fossil primates. Our measurements demonstrate that the omomyiforms Microchoerus, Necrolemur, Shoshonius, and Tetonius, adapiform Pronycticebus, and the possible lorisiform Plesiopithecus were likely nocturnal on the basis of orbit diameter. The adapiforms Leptadapis, Adapis, and Notharctus, the phylogenetically enigmatic Rooneyia, the early anthropoids Proteopithecus, Catopithecus, and Aegyptopithecus, and early platyrrhine Dolichocebus were likely diurnal. The activity pattern of the platyrrhine Tremacebus is obscure. Plesiopithecus, Pronycticebus, Microchoerus, and Necrolemur probably had

  9. Evaluation of a Public Child Eye Health Tertiary Facility for Pediatric Cataract in Southern Nigeria I: Visual Acuity Outcome

    PubMed Central

    Duke, Roseline E.; Adio, Adedayo; Oparah, Sidney K.; Odey, Friday; Eyo, Okon A.

    2016-01-01

    Purpose: A retrospective study of the outcome of congenital and developmental cataract surgery was conducted in a public child eye health tertiary facility in children <16 years of age in Southern Nigeria, as part of an evaluation. Materials and Method: Manual Small Incision Cataract Surgery with or without anterior vitrectomy was performed. The outcome measures were visual acuity (VA) and change (gain) in visual acuity. The age of the child at onset, duration of delay in presentation, ocular co-morbidity, non ocular co-morbidity, gender, and pre operative visual acuity were matched with postoperative visual acuity. A total of 66 children were studied for a period of six weeks following surgery. Results: Forty eight (72.7%) children had bilateral congenital cataracts and 18 (27.3%) children had bilateral developmental cataracts. There were 38(57.6%) males and 28 (42.4%) females in the study. Thirty Five (53%) children had good visual outcome (normal vision range 6/6/ -6/18) post-operatively. The number of children with blindness (vision <3/60) decreased from 61 (92.4%) pre-operatively to 4 (6.1%) post-operatively. Post operative complication occurred in 6.8% of cases six week after surgery. Delayed presentation had an inverse relationship with change (gain) in visual acuity (r = - 0.342; p-value = 0.005). Pre-operative visual acuity had a positive relationship with post operative change (gain) in visual acuity (r = 0.618; p-value = 0.000). Conclusion: Predictors of change in visual acuity in our study were; delayed presentation and pre-operative VA. Cataract surgery in children showed clinical benefit. PMID:27347247

  10. Luminescence of thermally altered human skeletal remains.

    PubMed

    Krap, Tristan; Nota, Kevin; Wilk, Leah S; van de Goot, Franklin R W; Ruijter, Jan M; Duijst, Wilma; Oostra, Roelof-Jan

    2017-02-23

    Literature on luminescent properties of thermally altered human remains is scarce and contradictory. Therefore, the luminescence of heated bone was systemically reinvestigated. A heating experiment was conducted on fresh human bone, in two different media, and cremated human remains were recovered from a modern crematory. Luminescence was excited with light sources within the range of 350 to 560 nm. The excitation light was filtered out by using different long pass filters, and the luminescence was analysed by means of a scoring method. The results show that temperature, duration and surrounding medium determine the observed emission intensity and bandwidth. It is concluded that the luminescent characteristic of bone can be useful for identifying thermally altered human remains in a difficult context as well as yield information on the perimortem and postmortem events.

  11. Odor analysis of decomposing buried human remains

    SciTech Connect

    Vass, Arpad Alexander; Smith, Rob R; Thompson, Cyril V; Burnett, Michael N; Dulgerian, Nishan; Eckenrode, Brian A

    2008-01-01

    This study, conducted at the University of Tennessee's Anthropological Research Facility (ARF), lists and ranks the primary chemical constituents which define the odor of decomposition of human remains as detected at the soil surface of shallow burial sites. Triple sorbent traps were used to collect air samples in the field and revealed eight major classes of chemicals which now contain 478 specific volatile compounds associated with burial decomposition. Samples were analyzed using gas chromatography-mass spectrometry (GC-MS) and were collected below and above the body, and at the soil surface of 1.5-3.5 ft. (0.46-1.07 m) deep burial sites of four individuals over a 4-year time span. New data were incorporated into the previously established Decompositional Odor Analysis (DOA) Database providing identification, chemical trends, and semi-quantitation of chemicals for evaluation. This research identifies the 'odor signatures' unique to the decomposition of buried human remains with projected ramifications on human remains detection canine training procedures and in the development of field portable analytical instruments which can be used to locate human remains in shallow burial sites.

  12. Juveniles' Motivations for Remaining in Prostitution

    ERIC Educational Resources Information Center

    Hwang, Shu-Ling; Bedford, Olwen

    2004-01-01

    Qualitative data from in-depth interviews were collected in 1990-1991, 1992, and 2000 with 49 prostituted juveniles remanded to two rehabilitation centers in Taiwan. These data are analyzed to explore Taiwanese prostituted juveniles' feelings about themselves and their work, their motivations for remaining in prostitution, and their difficulties…

  13. Identification of ancient remains through genomic sequencing

    PubMed Central

    Blow, Matthew J.; Zhang, Tao; Woyke, Tanja; Speller, Camilla F.; Krivoshapkin, Andrei; Yang, Dongya Y.; Derevianko, Anatoly; Rubin, Edward M.

    2008-01-01

    Studies of ancient DNA have been hindered by the preciousness of remains, the small quantities of undamaged DNA accessible, and the limitations associated with conventional PCR amplification. In these studies, we developed and applied a genomewide adapter-mediated emulsion PCR amplification protocol for ancient mammalian samples estimated to be between 45,000 and 69,000 yr old. Using 454 Life Sciences (Roche) and Illumina sequencing (formerly Solexa sequencing) technologies, we examined over 100 megabases of DNA from amplified extracts, revealing unbiased sequence coverage with substantial amounts of nonredundant nuclear sequences from the sample sources and negligible levels of human contamination. We consistently recorded over 500-fold increases, such that nanogram quantities of starting material could be amplified to microgram quantities. Application of our protocol to a 50,000-yr-old uncharacterized bone sample that was unsuccessful in mitochondrial PCR provided sufficient nuclear sequences for comparison with extant mammals and subsequent phylogenetic classification of the remains. The combined use of emulsion PCR amplification and high-throughput sequencing allows for the generation of large quantities of DNA sequence data from ancient remains. Using such techniques, even small amounts of ancient remains with low levels of endogenous DNA preservation may yield substantial quantities of nuclear DNA, enabling novel applications of ancient DNA genomics to the investigation of extinct phyla. PMID:18426903

  14. The case for fencing remains intact.

    PubMed

    Packer, C; Swanson, A; Canney, S; Loveridge, A; Garnett, S; Pfeifer, M; Burton, A C; Bauer, H; MacNulty, D

    2013-11-01

    Creel et al. argue against the conservation effectiveness of fencing based on a population measure that ignores the importance of top predators to ecosystem processes. Their statistical analyses consider, first, only a subset of fenced reserves and, second, an incomplete examination of 'costs per lion.' Our original conclusions remain unaltered.

  15. Predicting the remaining service life of concrete

    SciTech Connect

    Clifton, J.F.

    1991-11-01

    Nuclear power plants are providing, currently, about 17 percent of the U.S. electricity and many of these plants are approaching their licensed life of 40 years. The U.S. Nuclear Regulatory Commission and the Department of Energy`s Oak Ridge National Laboratory are carrying out a program to develop a methodology for assessing the remaining safe-life of the concrete components and structures in nuclear power plants. This program has the overall objective of identifying potential structural safety issues, as well as acceptance criteria, for use in evaluations of nuclear power plants for continued service. The National Institute of Standards and Technology (NIST) is contributing to this program by identifying and analyzing methods for predicting the remaining life of in-service concrete materials. This report examines the basis for predicting the remaining service lives of concrete materials of nuclear power facilities. Methods for predicting the service life of new and in-service concrete materials are analyzed. These methods include (1) estimates based on experience, (2) comparison of performance, (3) accelerated testing, (4) stochastic methods, and (5) mathematical modeling. New approaches for predicting the remaining service lives of concrete materials are proposed and recommendations for their further development given. Degradation processes are discussed based on considerations of their mechanisms, likelihood of occurrence, manifestations, and detection. They include corrosion, sulfate attack, alkali-aggregate reactions, frost attack, leaching, radiation, salt crystallization, and microbiological attack.

  16. Odor analysis of decomposing buried human remains.

    PubMed

    Vass, Arpad A; Smith, Rob R; Thompson, Cyril V; Burnett, Michael N; Dulgerian, Nishan; Eckenrode, Brian A

    2008-03-01

    This study, conducted at the University of Tennessee's Anthropological Research Facility (ARF), lists and ranks the primary chemical constituents which define the odor of decomposition of human remains as detected at the soil surface of shallow burial sites. Triple sorbent traps were used to collect air samples in the field and revealed eight major classes of chemicals which now contain 478 specific volatile compounds associated with burial decomposition. Samples were analyzed using gas chromatography-mass spectrometry (GC-MS) and were collected below and above the body, and at the soil surface of 1.5-3.5 ft. (0.46-1.07 m) deep burial sites of four individuals over a 4-year time span. New data were incorporated into the previously established Decompositional Odor Analysis (DOA) Database providing identification, chemical trends, and semi-quantitation of chemicals for evaluation. This research identifies the "odor signatures" unique to the decomposition of buried human remains with projected ramifications on human remains detection canine training procedures and in the development of field portable analytical instruments which can be used to locate human remains in shallow burial sites.

  17. Why Agricultural Educators Remain in the Classroom

    ERIC Educational Resources Information Center

    Crutchfield, Nina; Ritz, Rudy; Burris, Scott

    2013-01-01

    The purpose of this study was to identify and describe factors that are related to agricultural educator career retention and to explore the relationships between work engagement, work-life balance, occupational commitment, and personal and career factors as related to the decision to remain in the teaching profession. The target population for…

  18. Dependent coverage provision led to uneven insurance gains and unchanged mortality rates in young adult trauma patients.

    PubMed

    Scott, John W; Sommers, Benjamin D; Tsai, Thomas C; Scott, Kirstin W; Schwartz, Aaron L; Song, Zirui

    2015-01-01

    Insurance coverage has increased among young adults as a result of the Affordable Care Act (ACA) provision that allows young adults to remain covered under their parents' plans until age twenty-six. However, little is known about the provision's effects on the clinical outcomes and insurance coverage of patients with trauma--the most frequent cause of death and physical disability among young adults. Using 2007-12 data from the National Trauma Data Bank, we conducted a difference-in-differences analysis of coverage rates among trauma patients ages 19-25 (compared to patients ages 26-34, who served as the control group), and we examined trauma-relevant outcomes by patient, injury, and hospital characteristics. We found a 3.4-percentage-point decrease in uninsurance status among younger trauma patients following the policy change. The decrease was concentrated among men, non-Hispanic whites, those with relatively less severe injuries, and those who presented to nonteaching hospitals. We did not detect significant changes in the use of intensive care or in overall mortality. The heterogeneous coverage impact of the ACA dependent coverage provision on high- versus low-risk trauma patients has implications for future efforts to expand coverage.

  19. Foveal visual acuity is worse and shows stronger contour interaction effects for contrast-modulated than luminance-modulated Cs.

    PubMed

    Hairol, Mohd Izzuddin; Formankiewicz, Monika A; Waugh, Sarah J

    2013-05-01

    Contrast-modulated (CM) stimuli are processed by spatial mechanisms that operate at larger spatial scales than those processing luminance-modulated (LM) stimuli and may be more prone to deficits in developing, amblyopic, and aging visual systems. Understanding neural mechanisms of contour interaction or crowding will help in detecting disorders of spatial vision. In this study, contour interaction effects on visual acuity for LM and CM C and bar stimuli are assessed in normal foveal vision. In Experiment 1, visual acuity is measured for all-LM and all-CM stimuli, at ~3.5× above their respective modulation thresholds. In Experiment 2, visual acuity is measured for Cs and bars of different type (LM C with CM bars and vice versa). Visual acuity is degraded for CM compared with LM Cs (0.46 ± 0.04 logMAR vs. 0.18 ± 0.04 logMAR). With nearby bars, CM acuity is degraded further (0.23 ± 0.01 logMAR or ~2 lines on an acuity chart), significantly more than LM acuity (0.11 ± 0.01 logMAR, ~1 line). Contour interaction for CM stimuli extends over greater distances (arcmin) than it does for LM stimuli, but extents are similar with respect to acuities (~3.5× the C gap width). Contour interaction is evident when the Cs and bars are defined differently: it is stronger when an LM C is flanked by CM bars (0.17 ± 0.03 logMAR) than when a CM C is flanked by LM bars (0.08 ± 0.02 logMAR). Our results suggest that contour interaction for foveally viewed acuity stimuli involves feature integration, such that the outputs of receptive fields representing Cs and bars are combined. Contour interaction operates at LM and CM representational stages, it can occur across stage, and it is enhanced at the CM stage. Greater contour interaction for CM Cs and bars could hold value for visual acuity testing and earlier diagnosis of conditions for which crowding is important, such as in amblyopia.

  20. PERSPECTIVE: Is acuity enough? Other considerations in clinical investigations of visual prostheses

    NASA Astrophysics Data System (ADS)

    Lepri, Bernard P.

    2009-06-01

    Visual impairing eye diseases are the major frontier facing ophthalmic research today in light of our rapidly aging population. The visual skills necessary for improving the quality of daily function and life are inextricably linked to these impairing diseases. Both research and reimbursement programs are emphasizing outcome-based results. Is improvement in visual acuity alone enough to improve the function and quality of life of visually impaired persons? This perspective summarizes the types of effectiveness endpoints for clinical investigations of visual prostheses that go beyond visual acuity. The clinical investigation of visual prostheses should include visual function, functional vision and quality of life measures. Specifically, they encompass contrast sensitivity, orientation and mobility, activities of daily living and quality of life assessments. The perspective focuses on the design of clinical trials for visual prostheses and the methods of determining effectiveness above and beyond visual acuity that will yield outcomes that are measured by improved function in the visual world and quality of life. The visually impaired population is the primary consideration in this presentation with particular emphases on retinitis pigmentosa and age-related macular degeneration. Clinical trials for visual prostheses cannot be isolated from the need for medical rehabilitation in order to obtain measurements of effectiveness that produce outcomes/evidence-based success. This approach will facilitate improvement in daily function and quality of life of patients with diseases that cause chronic vision impairment. The views and opinions are those of the author and do not necessarily reflect those of the US Food and Drug Administration, the US Department of Health and Human Services or the Public Health Service.

  1. Seeing Steps and Ramps with Simulated Low Acuity: Impact of Texture and Locomotion

    PubMed Central

    Bochsler, Tiana M.; Legge, Gordon E.; Kallie, Christopher S.; Gage, Rachel

    2012-01-01

    Purpose Detecting and recognizing steps and ramps is an important component of the visual accessibility of public spaces for people with impaired vision. The present study, which is part of a larger program of research on visual accessibility, investigated the impact of two factors that may facilitate the recognition of steps and ramps during low-acuity viewing. Visual texture on the ground plane is an environmental factor that improves judgments of surface distance and slant. Locomotion (walking) is common during observations of a layout, and may generate visual motion cues that enhance the recognition of steps and ramps. Methods In two experiments, normally sighted subjects viewed the targets monocularly through blur goggles that reduced acuity to either approx. 20/150 Snellen (mild blur) or 20/880 (severe blur). The subjects judged whether a step, ramp or neither was present ahead on a sidewalk. In the texture experiment, subjects viewed steps and ramps on a surface with a coarse black-and-white checkerboard pattern. In the locomotion experiment, subjects walked along the sidewalk toward the target before making judgments. Results Surprisingly, performance was lower with the textured surface than with a uniform surface, perhaps because the texture masked visual cues necessary for target recognition. Subjects performed better in walking trials than in stationary trials, possibly because they were able to take advantage of visual cues that were only present during motion. Conclusions We conclude that under conditions of simulated low acuity, large, high-contrast texture elements can hinder the recognition of steps and ramps while locomotion enhances recognition. PMID:22863792

  2. Contrast-sensitivity loss in a group of former microelectronics workers with normal visual acuity.

    PubMed

    Frenette, B; Mergler, D; Bowler, R

    1991-07-01

    The measurement of contrast sensitivity at varying grating frequencies is used increasingly to study visual and neural disorders. It provides more information than conventional acuity measures. Refractive errors initially affect high spatial frequencies, whereas lower spatial frequencies are affected only when these errors are pronounced. Neurophysiological alterations are reflected by depressed sensitivity to coarse gratings. Visual dysfunction has been associated with workplace exposures to a wide range of organic solvents. In microelectronics assembly where large quantities of organic solvents are used in many aspects of the work processes, visual deficits have been observed. The objective of the present study was to compare contrast sensitivity among former microelectronics assembly workers, with normal far and near visual acuity, and a reference group from the same region, with similar acuity. No significant differences were observed between scores at the two ends of the contrast sensitivity curves; however, at the intermediate spatial frequencies, the former microelectronics workers' scores were significantly lower (Student's t-test; p less than 0.05). For the microelectronics workers, no relation was observed between age and contrast sensitivity at any spatial frequency, whereas for the reference group, contrast sensitivity scores were progressively lower with age at spatial frequencies greater than or equal to 6.0 cpd (r2 = 0.15 at 6 cpd to r2 = 0.45 at 18.0 cpd), suggesting that for the former there is some form of interference with the expected contrast sensitivity loss with age. Lower contrast sensitivity scores in intermediate spatial frequencies, observed among the former microelectronics workers, possibly reflect neural alterations, which may have resulted from exposure to neurotoxic substances. These findings suggest the need for further studies on visual functions in microelectronics workers.

  3. Measurement of Vibration Detection Threshold and Tactile Spatial Acuity in Human Subjects.

    PubMed

    Moshourab, Rabih; Frenzel, Henning; Lechner, Stefan; Haseleu, Julia; Bégay, Valérie; Omerbašić, Damir; Lewin, Gary R

    2016-09-01

    Tests that allow the precise determination of psychophysical thresholds for vibration and grating orientation provide valuable information about mechanosensory function that are relevant for clinical diagnosis as well as for basic research. Here, we describe two psychophysical tests designed to determine the vibration detection threshold (automated system) and tactile spatial acuity (handheld device). Both procedures implement a two-interval forced-choice and a transformed-rule up and down experimental paradigm. These tests have been used to obtain mechanosensory profiles for individuals from distinct human cohorts such as twins or people with sensorineural deafness.

  4. Explosives remain preferred methods for platform abandonment

    SciTech Connect

    Pulsipher, A.; Daniel, W. IV; Kiesler, J.E.; Mackey, V. III

    1996-05-06

    Economics and safety concerns indicate that methods involving explosives remain the most practical and cost-effective means for abandoning oil and gas structures in the Gulf of Mexico. A decade has passed since 51 dead sea turtles, many endangered Kemp`s Ridleys, washed ashore on the Texas coast shortly after explosives helped remove several offshore platforms. Although no relationship between the explosions and the dead turtles was ever established, in response to widespread public concern, the US Minerals Management Service (MMS) and National Marine Fisheries Service (NMFS) implemented regulations limiting the size and timing of explosive charges. Also, more importantly, they required that operators pay for observers to survey waters surrounding platforms scheduled for removal for 48 hr before any detonations. If observers spot sea turtles or marine mammals within the danger zone, the platform abandonment is delayed until the turtles leave or are removed. However, concern about the effects of explosives on marine life remains.

  5. Becoming and remaining homeless: a qualitative investigation.

    PubMed

    Morrell-Bellai, T; Goering, P N; Boydell, K M

    2000-09-01

    This article reports the qualitative findings of a multimethod study of the homeless population in Toronto, Canada. The qualitative component sought to identify how people become homeless and why some individuals remain homeless for an extended period of time or cycle in and out of homelessness (the chronically homeless). In-depth, semistructured interviews were conducted with 29 homeless adults. The findings suggest that people both become and remain homeless due to a combination of macro level factors (poverty, lack of employment, low welfare wages, lack of affordable housing) and personal vulnerability (childhood abuse or neglect, mental health symptoms, impoverished support networks, substance abuse). Chronically homeless individuals often reported experiences of severe childhood trauma and tended to attribute their continued homelessness to a substance abuse problem. It is concluded that both macro and individual level factors must be considered in planning programs and services to address the issue of homelessness in Canada.

  6. Mill and the right to remain uninformed.

    PubMed

    Strasser, M

    1986-08-01

    In a recent article in the Journal of Medicine and Philosophy, David Ost (1984) claims that patients do not have a right to waive their right to information. He argues that patients cannot make informed rational decisions without full information and thus, a right to waive information would involve a right to avoid one's responsibility to act as an autonomous moral agent. In support of his position, Ost cites a passage from Mill. Yet, a correct interpretation of the passage in question would support one's right to remain uninformed in certain situations. If the information would hurt one's chances for survival or hurt one's ability to make calm, rational decisions, then one not only does not have a duty to find out the information, but one's exercising one's right to remain uninformed may be the only rational course of action to take.

  7. [Professional confidentiality: speak out or remain silent? ].

    PubMed

    Daubigney, Jean-claude

    2014-01-01

    People who work with children, in their daily tasks, must choose whether to disclose information entrusted to them. However, they are subject to the law, which authorises or imposes speaking out or remaining silent. In terms of ethics, they can seek the best possible response while respecting professional secrecy when meeting an individual, in a situation, in a place or at a particular time. They must then take responsibility for that decision.

  8. 13 percent remain AIDS-free.

    PubMed

    1995-01-01

    Researchers predict that approximately thirteen percent of homosexual/bisexual men infected with HIV at an early age will be long-term survivors, remaining free of disease for more than twenty years. Researchers with the Multicenter AIDS Cohort Study based their predictions on data from the ongoing study of 1,809 HIV-positive men. Stable immune markers and no use of antiretrovirals were the criteria used to define long-term.

  9. Direct Dating of Hominids Remains In Eurasia

    NASA Astrophysics Data System (ADS)

    Yokoyama, Y.; Falguères, C.

    When archaeological sites are associated with human remains, it is relevant to be able to date those valuable remains for different reasons. The main one is that it avoids the stratigraphical problems which can be due to intrusive burials in the sequence. The other reason consists in the fact that human bones may be encountered out of established stratigraphical context. On the other hand, the majority of dating methods currently used are destructive and can not be applied on these precious samples particularly when they are older than 40,000 years and can not be dated by radiocarbon. Since several years, we have developped a completely non-destructive method which consists in the measurement of human remains using the gamma -ray spectrometry. This technique has been used recently by other laboratories. We present here two important cases for the knowledge of human evolution in Eurasia. The first example is Qafzeh site in Israel where many human skeletons have been unearthed from burials associated with fauna and lithic artefacts. This site has been dated by several independent radiometric methods. So, it was possible to compare our gamma results with the other results yielded by the different methods. The second case concerns the most evolved Homo erectus found in Java, Indonesia, at Ngandong site, close to the Solo river. A recent debate has been focused on the age of these fossils and their direct dating is of outmost importance for the knowledge of settlement of Modern Humans in South-East Asia.

  10. Visual Acuity, Contrast Sensitivity and Color Vision Three Years After Iodine-125 Brachytherapy for Choroidal and Ciliary Body Melanoma

    PubMed Central

    Tsui, Irena; Beardsley, Robert M; McCannel, Tara A; Oliver, Scott C; Chun, Melissa W; Lee, Steve P; Chow, Phillip E; Agazaryan, Nzhde; Yu, Fei; Straatsma, Bradley R

    2015-01-01

    Purpose : To report visual acuity, contrast sensitivity and color vision prior to, 1 year after, 2 years after and 3 years after iodine-125 brachytherapy for choroidal and ciliary body melanoma (CCM). Design : Prospective interventional case series. Participants : Thirty-seven patients (37 eyes) with CCM. Methods : Patients had best-corrected Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity, Pelli-Robson contrast sensitivity and Hardy-Rand-Rittler color vision measurement; comprehensive ophthalmology examination; optical coherence tomography; and ultrasonography at baseline prior to, 1 year after, 2 years after and 3 years after I-125 brachytherapy. Main Outcome Measures : Visual acuity, contrast sensitivity and color vision prior to, 1 year after, 2 years after and 3 years after brachytherapy. Results : Nineteen (19) men and 18 women with mean age of 58 years (SD 13, range 30-78) prior to, 1 year after, 2 years after and 3 years after brachytherapy had mean best-corrected visual acuity of 77 letters (20/32), 65 letters (20/50), 56 letters (20/80) and 47 letters (20/125); contrast sensitivity of 30, 26, 22 and 19 letters; color vision of 26, 20, 17 and 14 test figures, respectively. Decrease in visual acuity, contrast sensitivity and color vision was statistically significant from baseline at 1 year, 2 years, and 3 years after brachytherapy. Decreased acuity at 3 years was associated with mid-choroid and macula melanoma location, ≥ 4.1 mm melanoma height, radiation maculopathy and radiation optic neuropathy. Conclusion : 1, 2 and 3 years after brachytherapy, eyes with CCM had significantly decreased visual acuity, contrast sensitivity and color vision. PMID:26312123

  11. Statewide retrospective study of low acuity emergency presentations in New South Wales, Australia: who, what, where and why?

    PubMed Central

    Dinh, Michael M; Berendsen Russell, Saartje; Bein, Kendall J; Chalkley, Dane R; Muscatello, David; Paoloni, Richard; Ivers, Rebecca

    2016-01-01

    Objective The present study aims to use a statewide population-based registry to assess the prevalence of low acuity emergency department (ED) presentations, describe the trend in presentation rates and to determine whether they were associated with various presentation characteristics such as the type of hospital as well as clinical and demographic variables. Design and setting This was a retrospective analysis of a population-based registry of ED presentations in New South Wales (NSW). Generalised estimating equations with log links were used to determine factors associated with low acuity presentations to account for repeat presentations and the possibility of clustering of outcomes. Participants Patients were included in this analysis if they presented to an ED between January 2010 and December 2014. The outcomes of interest were low acuity presentation, defined as those who self-presented (were not transported by ambulance), were assigned a triage category of 4 or 5 (semiurgent or non-urgent) and discharged back to usual residence from ED. Results There were 10.7 million ED presentations analysed. Of these, 45% were classified as a low acuity presentation. There was no discernible increase in the rate of low acuity presentations across NSW between 2010 and 2014. The strongest predictors of low acuity ED presentation were age <40 years of age (OR 1.77); injury or musculoskeletal administrative and non-urgent procedures (OR 2.96); ear, nose and throat, eye or oral (OR 5.53); skin or allergy-type presenting problems (OR 2.84). Conclusions Low acuity ED presentations comprise almost half of all ED presentations. Alternative emergency models of care may help meet the needs of these patients. PMID:27165649

  12. Baseline Characteristics of the Infant Aphakia Treatment Study Population: Predicting Recognition Acuity at 4.5 Years of Age

    PubMed Central

    Hartmann, E. Eugenie; Lynn, Michael J.; Lambert, Scott R.

    2015-01-01

    Purpose. To identify patient baseline characteristics that predict recognition acuity at 4.5 years of age in the Infant Aphakia Treatment Study, a study of patients with monocular infantile cataracts. Methods. We analyzed baseline characteristics of the 114 infants enrolled in the Infant Aphakia Treatment Study to determine which were most predictive of visual outcome at 4.5 years of age. All infants underwent cataract surgery between 1 and 7 months of age. Monocular acuity was assessed at 4.5 years of age by a traveling examiner using the Amblyopia Treatment Study HOTV protocol. Results. Age at cataract surgery was weakly associated with visual acuity (Spearman rank correlation coefficient = 0.19, P = 0.041) with median visual acuity better among the younger patients (28–48 days: 0.50 logMAR, 49–210 days: 1.10 logMAR, P = 0.046). Patients from families with private insurance had significantly better median visual acuity (0.60 vs. 1.40 logMAR, P = 0.0004). No other baseline characteristic revealed a significant bivariate relationship with visual acuity. A multiple linear regression relating visual acuity to all baseline characteristics demonstrated that only the availability of private insurance was statistically significant, accounting for 12% of the variance. Conclusions. This analysis concurs with previous studies that early surgery is important for good visual outcomes in patients with unilateral infantile cataracts. The fact that only one baseline variable (private insurance) contributed to the multivariate analysis, accounting for 12% of the variance, suggests that predicting visual outcome for these patients is complicated at best, and cannot be estimated from baseline characteristics alone. (ClinicalTrials.gov number, NCT00212134.) PMID:25503455

  13. Distribution of albatross remains in the Far East regions during the Holocene, based on zooarchaeological remains.

    PubMed

    Eda, Masaki; Higuchi, Hiroyoshi

    2004-07-01

    Many albatross remains have been found in the Japanese Islands and the surrounding areas, such as Sakhalin and South Korea. These remains are interesting for two reasons: numerous sites from which albatross remains have been found are located in coastal regions of the Far East where no albatrosses have been distributed recently, and there are some sites in which albatross remains represent a large portion of avian remains, although albatrosses are not easily preyed upon by human beings. We collected data on albatross remains from archaeological sites in the Far East regions during the Holocene and arranged the remains geographically, temporally and in terms of quantity. Based on these results, we showed that coastal areas along the Seas of Okhotsk and Japan have rarely been used by albatrosses in Modern times, though formerly there were many albatrosses. We proposed two explanations for the shrinkage of their distributional range: excessive hunting in the breeding areas, and distributional changes of prey for albatrosses.

  14. Why Do Some Cores Remain Starless?

    NASA Astrophysics Data System (ADS)

    Anathpindika, S.

    2016-08-01

    Prestellar cores, by definition, are gravitationally bound but starless pockets of dense gas. Physical conditions that could render a core starless (in the local Universe) is the subject of investigation in this work. To this end, we studied the evolution of four starless cores, B68, L694-2, L1517B, L1689, and L1521F, a VeLLO. We demonstrate: (i) cores contracted in quasistatic manner over a timescale on the order of ~ 105 yr. Those that remained starless briefly acquired a centrally concentrated density configuration that mimicked the profile of a unstable BonnorEbert sphere before rebounding, (ii) three cores viz. L694-2, L1689-SMM16, and L1521F remained starless despite becoming thermally super-critical. By contrast, B68 and L1517B remained sub-critical; L1521F collapsed to become a VeLLO only when gas-cooling was enhanced by increasing the size of dust-grains. This result is robust, for other starless cores viz. B68, L694-2, L1517B, and L1689 could also be similarly induced to collapse. The temperature-profile of starless cores and those that collapsed was found to be radically different. While in the former type, only very close to the centre of a core was there any evidence of decline in gas temperature, by contrast, a core of the latter type developed a more uniformly cold interior. Our principle conclusions are: (a) thermal super-criticality of a core is insufficient to ensure it will become protostellar, (b) potential star-forming cores (the VeLLO L1521F here), could be experiencing dust-coagulation that must enhance gasdust coupling and in turn lower gas temperature, thereby assisting collapse. This also suggests, mere gravitational/virial boundedness of a core is insufficient to ensure it will form stars.

  15. 51-L Challenger Crew Remains Transferred

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The Challenger crewmember remains are being transferred from 7 hearse vehicles to a MAC C-141 transport plane at the Kennedy Space Center's Shuttle Landing Facility for transport to Dover Air Force Base, Delaware. The STS-51L crew consisted of: Mission Specialist, Ellison S. Onizuka, Teacher in Space Participant Sharon Christa McAuliffe, Payload Specialist, Greg Jarvis and Mission Specialist, Judy Resnik. In the front row from left to right: Pilot Mike Smith, Commander, Dick Scobee and Mission Specialist, Ron McNair.

  16. Visual acuity of the honey bee retina and the limits for feature detection

    PubMed Central

    Rigosi, Elisa; Wiederman, Steven D.; O’Carroll, David C.

    2017-01-01

    Visual abilities of the honey bee have been studied for more than 100 years, recently revealing unexpectedly sophisticated cognitive skills rivalling those of vertebrates. However, the physiological limits of the honey bee eye have been largely unaddressed and only studied in an unnatural, dark state. Using a bright display and intracellular recordings, we here systematically investigated the angular sensitivity across the light adapted eye of honey bee foragers. Angular sensitivity is a measure of photoreceptor receptive field size and thus small values indicate higher visual acuity. Our recordings reveal a fronto-ventral acute zone in which angular sensitivity falls below 1.9°, some 30% smaller than previously reported. By measuring receptor noise and responses to moving dark objects, we also obtained direct measures of the smallest features detectable by the retina. In the frontal eye, single photoreceptors respond to objects as small as 0.6° × 0.6°, with >99% reliability. This indicates that honey bee foragers possess significantly better resolution than previously reported or estimated behaviourally, and commonly assumed in modelling of bee acuity. PMID:28383025

  17. Taste acuity, plasma zinc levels, and weight loss during radiotherapy: a study of relationships

    SciTech Connect

    Bolze, M.S.; Fosmire, G.J.; Stryker, J.A.; Chung, C.K.; Flipse, B.G.

    1982-07-01

    Thirty-five patients who were to undergo radiotherapy and 13 normal subjects were evaluated with taste questionnaires, taste acuity tests, and plasma zinc analyses. The studies were repeated on the patients in the fifth week of radiotherapy. The mean taste thresholds for NaCl (salt), sucrose (sweet), HCl (sour), and urea (bitter) were elevated and the plasma zinc levels were lower (77.2 +/- 11.8 vs. 94.6 +/- 30.1 g/100 ml, p = 0.055) for the patients than for the controls. However, there was not a significant correlation between the taste thresholds and plasma zinc levels at any time. The mean weight loss experienced by the 14 patients who reported subjective taste alteration in the fifth week was 3.1 kg versus 0.1 kg (p = 0.005) for those who did not report taste alteration. The data suggest that alterations in taste acuity, but not plasma zinc levels, are associated with weight loss during radiotherapy.

  18. Taste acuity, plasma zinc levels, and weight loss during radiotherapy: a study of relationships

    SciTech Connect

    Bolze, M.S.; Fosmire, G.J.; Stryker, J.A.; Chung, C.K.; Flipse, B.G.

    1982-07-01

    Thirty-five patients who were to undergo radiotherapy and 13 normal subjects were evaluated with taste questionnaires, taste acuity tests, and plasma zinc analyses. The studies were repeated on the patients in the fifth week of radiotherapy. The mean taste thresholds for NaCl (salt), sucrose (sweet), HCl (sour), and urea (bitter) were elevated and the plasma zinc levels were lower (77.2 +/- 11.8 vs. 94.6 +/- 30.1 g/100 ml, p . 0.055) for the patients than for the controls. However, there was not a significant correlation between the taste thresholds and plasma zinc levels at any time. The mean weight loss experienced by the 14 patients who reported subjective taste alteration in the fifth week was 3.1 kg versus 0.1 kg (p . 0.005) for those who did not report taste alteration. The data suggest that alterations in taste acuity, but not plasma zinc levels, are associated with weight loss during radiotherapy.

  19. Effectiveness of exome and genome sequencing guided by acuity of illness for diagnosis of neurodevelopmental disorders

    PubMed Central

    Soden, Sarah E.; Saunders, Carol J.; Willig, Laurel K.; Farrow, Emily G.; Smith, Laurie D.; Petrikin, Josh E.; LePichon, Jean-Baptiste; Miller, Neil A.; Thiffault, Isabelle; Dinwiddie, Darrell L.; Twist, Greyson; Noll, Aaron; Heese, Bryce A.; Zellmer, Lee; Atherton, Andrea M.; Abdelmoity, Ahmed T.; Safina, Nicole; Nyp, Sarah S.; Zuccarelli, Britton; Larson, Ingrid A.; Modrcin, Ann; Herd, Suzanne; Creed, Mitchell; Ye, Zhaohui; Yuan, Xuan; Brodsky, Robert A.; Kingsmore, Stephen F.

    2014-01-01

    Neurodevelopmental disorders (NDDs) affect more than 3% of children and are attributable to single-gene mutations at more than 1000 loci. Traditional methods yield molecular diagnoses in less than one-half of children with NDD. Whole-genome sequencing (WGS) and whole-exome sequencing (WES) can enable diagnosis of NDD, but their clinical and cost-effectiveness are unknown. One hundred families with 119 children affected by NDD received diagnostic WGS and/or WES of parent-child trios, wherein the sequencing approach was guided by acuity of illness. Forty-five percent received molecular diagnoses. An accelerated sequencing modality, rapid WGS, yielded diagnoses in 73% of families with acutely ill children (11 of 15). Forty percent of families with children with nonacute NDD, followed in ambulatory care clinics (34 of 85), received diagnoses: 33 by WES and 1 by staged WES then WGS. The cost of prior negative tests in the nonacute patients was $19,100 per family, suggesting sequencing to be cost-effective at up to $7640 per family. A change in clinical care or impression of the pathophysiology was reported in 49% of newly diagnosed families. If WES or WGS had been performed at symptom onset, genomic diagnoses may have been made 77 months earlier than occurred in this study. It is suggested that initial diagnostic evaluation of children with NDD should include trio WGS or WES, with extension of accelerated sequencing modalities to high-acuity patients. PMID:25473036

  20. Microperimetric Biofeedback Training Improved Visual Acuity after Successful Macular Hole Surgery

    PubMed Central

    Ueda-Consolvo, Tomoko; Otsuka, Mitsuya; Hayashi, Yumiko; Ishida, Masaaki; Hayashi, Atsushi

    2015-01-01

    Purpose. To evaluate the efficacy of setting a preferred retinal locus relocation target (PRT) and performing Macular Integrity Assessment (MAIA) biofeedback training in patients showing insufficient recovery of best corrected visual acuity (BCVA) despite successful closure of an idiopathic macular hole (MH). Methods. Retrospective interventional case series. Nine eyes of 9 consecutive patients with the decimal BCVA of less than 0.6 at more than 3 months after successful MH surgery were included. A PRT was chosen based on MAIA microperimetry and the patients underwent MAIA biofeedback training. BCVA, reading speed, fixation stability, and 63% bivariate contour ellipse area (BCEA) were evaluated before and after the training. Statistical analysis was carried out using paired Student's t-test. Results. PRT was chosen on the nasal side of the closed MH fovea in 8 patients. After the MAIA training, BCVA improved in all patients. The mean logMAR value of BCVA significantly improved from 0.33 to 0.12 (p = 0.007). Reading speed improved in all patients (p = 0.29), fixation stability improved in 5 patients (p = 0.70), and 63% BCEA improved in 7 patients (p = 0.21), although these improvements were not statistically significant. Conclusion. MAIA biofeedback training improved visual acuity in patients with insufficient recovery of BCVA after successful MH surgery. PMID:26783452

  1. Comparison of distance and near visual acuity in patients with vision loss due to cataract.

    PubMed

    Mercado, Carmel L; Doroslovački, Pavle; Wang, Jiangxia; Siddiqui, Aazim A; Kolker, Andrew F; Kolker, Richard J

    2017-02-01

    The purpose of this study was to assess whether there is a disparity in distance and near best-corrected visual acuity (BCVA) in cataract eyes. 102 patients with cataract (N = 121 eyes) were seen in clinic between January and November 2013 at the Wilmer Eye Institute Comprehensive Eye Service. An age-related macular degeneration (ARMD) group (N = 27 eyes) was also identified for comparison. Distance and near BCVA were measured as part of the standard ophthalmic evaluation. Snellen measurements were converted to their LogMAR equivalents for statistical analysis. Near was better than distance BCVA with mean difference of 1.38 lines (P < 0.001) in the cataract eyes. This disparity was not seen in the ARMD eyes. Near-distance BCVA disparity is a statistically significant finding seen with cataracts. This may have further implications in patients with both cataract and ARMD as the presence of disparity may suggest a cataract etiology playing a greater role in vision loss. This comparison may be useful for surgical prognostication and as a quick triage tool in conjunction with, or in place of, a potential acuity meter and dilated near-pinhole test.

  2. Simulation of thalamic prosthetic vision: reading accuracy, speed, and acuity in sighted humans

    PubMed Central

    Vurro, Milena; Crowell, Anne Marie; Pezaris, John S.

    2014-01-01

    The psychophysics of reading with artificial sight has received increasing attention as visual prostheses are becoming a real possibility to restore useful function to the blind through the coarse, pseudo-pixelized vision they generate. Studies to date have focused on simulating retinal and cortical prostheses; here we extend that work to report on thalamic designs. This study examined the reading performance of normally sighted human subjects using a simulation of three thalamic visual prostheses that varied in phosphene count, to help understand the level of functional ability afforded by thalamic designs in a task of daily living. Reading accuracy, reading speed, and reading acuity of 20 subjects were measured as a function of letter size, using a task based on the MNREAD chart. Results showed that fluid reading was feasible with appropriate combinations of letter size and phosphene count, and performance degraded smoothly as font size was decreased, with an approximate doubling of phosphene count resulting in an increase of 0.2 logMAR in acuity. Results here were consistent with previous results from our laboratory. Results were also consistent with those from the literature, despite using naive subjects who were not trained on the simulator, in contrast to other reports. PMID:25408641

  3. Simulation of thalamic prosthetic vision: reading accuracy, speed, and acuity in sighted humans.

    PubMed

    Vurro, Milena; Crowell, Anne Marie; Pezaris, John S

    2014-01-01

    The psychophysics of reading with artificial sight has received increasing attention as visual prostheses are becoming a real possibility to restore useful function to the blind through the coarse, pseudo-pixelized vision they generate. Studies to date have focused on simulating retinal and cortical prostheses; here we extend that work to report on thalamic designs. This study examined the reading performance of normally sighted human subjects using a simulation of three thalamic visual prostheses that varied in phosphene count, to help understand the level of functional ability afforded by thalamic designs in a task of daily living. Reading accuracy, reading speed, and reading acuity of 20 subjects were measured as a function of letter size, using a task based on the MNREAD chart. Results showed that fluid reading was feasible with appropriate combinations of letter size and phosphene count, and performance degraded smoothly as font size was decreased, with an approximate doubling of phosphene count resulting in an increase of 0.2 logMAR in acuity. Results here were consistent with previous results from our laboratory. Results were also consistent with those from the literature, despite using naive subjects who were not trained on the simulator, in contrast to other reports.

  4. Night vision goggle (NVG) visual acuity under ideal conditions with various adjustment procedures.

    PubMed

    DeVilbiss, C A; Antonio, J C; Fiedler, G M

    1994-08-01

    Night operations involve diverse mission areas and require an increased reliance on the use of night vision devices, such as night vision goggles (NVG's). Any reduction in goggle or visual performance which goes undetected can have a serious effect on flight safety and operational capability. Under controlled lighting conditions, a crewmember should be able to obtain the best possible goggle performance, and to determine if the goggle is functioning properly. These data represent a sample of 218 current USAF aircrew members representing all crew positions in both rotary and fixed-wing aircraft. Three measurements of goggle performance, expressed as NVG visual acuity, were obtained. The first measure, obtained after crewmembers adjusted the goggles with their usual adjustment methods, showed that they routinely obtain less than optimal acuity levels; i.e., averaging between 20/50 and 20/55. The second measure, taken when the NVG Resolution Chart was provided to augment their "usual" method of adjustment, showed improved performance; i.e., averaging 20/45. The third measure, taken following participation in an NVG Adjustment Procedures class, showed the greatest improvement, averaging between 20/35 and 20/40. In summary, it is reasonable to conclude that aircrew members who are able to obtain the best possible performance for their NVG's under controlled preflight conditions will obtain the best possible goggle performance under the widely varying flight conditions.

  5. Impact on stereo-acuity of two presbyopia correction approaches: monovision and small aperture inlay.

    PubMed

    Fernández, Enrique J; Schwarz, Christina; Prieto, Pedro M; Manzanera, Silvestre; Artal, Pablo

    2013-06-01

    Some of the different currently applied approaches that correct presbyopia may reduce stereovision. In this work, stereo-acuity was measured for two methods: (1) monovision and (2) small aperture inlay in one eye. When performing the experiment, a prototype of a binocular adaptive optics vision analyzer was employed. The system allowed simultaneous measurement and manipulation of the optics in both eyes of a subject. The apparatus incorporated two programmable spatial light modulators: one phase-only device using liquid crystal on silicon technology for wavefront manipulation and one intensity modulator for controlling the exit pupils. The prototype was also equipped with a stimulus generator for creating retinal disparity based on two micro-displays. The three-needle test was programmed for characterizing stereo-acuity. Subjects underwent a two-alternative forced-choice test. The following cases were tested for the stimulus placed at distance: (a) natural vision; (b) 1.5 D monovision; (c) 0.75 D monovision; (d) natural vision and small pupil; (e) 0.75 D monovision and small pupil. In all cases the standard pupil diameter was 4 mm and the small pupil diameter was 1.6 mm. The use of a small aperture significantly reduced the negative impact of monovision on stereopsis. The results of the experiment suggest that combining micro-monovision with a small aperture, which is currently being implemented as a corneal inlay, can yield values of stereoacuity close to those attained under normal binocular vision.

  6. Impact on stereo-acuity of two presbyopia correction approaches: monovision and small aperture inlay

    PubMed Central

    Fernández, Enrique J.; Schwarz, Christina; Prieto, Pedro M.; Manzanera, Silvestre; Artal, Pablo

    2013-01-01

    Some of the different currently applied approaches that correct presbyopia may reduce stereovision. In this work, stereo-acuity was measured for two methods: (1) monovision and (2) small aperture inlay in one eye. When performing the experiment, a prototype of a binocular adaptive optics vision analyzer was employed. The system allowed simultaneous measurement and manipulation of the optics in both eyes of a subject. The apparatus incorporated two programmable spatial light modulators: one phase-only device using liquid crystal on silicon technology for wavefront manipulation and one intensity modulator for controlling the exit pupils. The prototype was also equipped with a stimulus generator for creating retinal disparity based on two micro-displays. The three-needle test was programmed for characterizing stereo-acuity. Subjects underwent a two-alternative forced-choice test. The following cases were tested for the stimulus placed at distance: (a) natural vision; (b) 1.5 D monovision; (c) 0.75 D monovision; (d) natural vision and small pupil; (e) 0.75 D monovision and small pupil. In all cases the standard pupil diameter was 4 mm and the small pupil diameter was 1.6 mm. The use of a small aperture significantly reduced the negative impact of monovision on stereopsis. The results of the experiment suggest that combining micro-monovision with a small aperture, which is currently being implemented as a corneal inlay, can yield values of stereoacuity close to those attained under normal binocular vision. PMID:23761846

  7. Effectiveness of exome and genome sequencing guided by acuity of illness for diagnosis of neurodevelopmental disorders.

    PubMed

    Soden, Sarah E; Saunders, Carol J; Willig, Laurel K; Farrow, Emily G; Smith, Laurie D; Petrikin, Josh E; LePichon, Jean-Baptiste; Miller, Neil A; Thiffault, Isabelle; Dinwiddie, Darrell L; Twist, Greyson; Noll, Aaron; Heese, Bryce A; Zellmer, Lee; Atherton, Andrea M; Abdelmoity, Ahmed T; Safina, Nicole; Nyp, Sarah S; Zuccarelli, Britton; Larson, Ingrid A; Modrcin, Ann; Herd, Suzanne; Creed, Mitchell; Ye, Zhaohui; Yuan, Xuan; Brodsky, Robert A; Kingsmore, Stephen F

    2014-12-03

    Neurodevelopmental disorders (NDDs) affect more than 3% of children and are attributable to single-gene mutations at more than 1000 loci. Traditional methods yield molecular diagnoses in less than one-half of children with NDD. Whole-genome sequencing (WGS) and whole-exome sequencing (WES) can enable diagnosis of NDD, but their clinical and cost-effectiveness are unknown. One hundred families with 119 children affected by NDD received diagnostic WGS and/or WES of parent-child trios, wherein the sequencing approach was guided by acuity of illness. Forty-five percent received molecular diagnoses. An accelerated sequencing modality, rapid WGS, yielded diagnoses in 73% of families with acutely ill children (11 of 15). Forty percent of families with children with nonacute NDD, followed in ambulatory care clinics (34 of 85), received diagnoses: 33 by WES and 1 by staged WES then WGS. The cost of prior negative tests in the nonacute patients was $19,100 per family, suggesting sequencing to be cost-effective at up to $7640 per family. A change in clinical care or impression of the pathophysiology was reported in 49% of newly diagnosed families. If WES or WGS had been performed at symptom onset, genomic diagnoses may have been made 77 months earlier than occurred in this study. It is suggested that initial diagnostic evaluation of children with NDD should include trio WGS or WES, with extension of accelerated sequencing modalities to high-acuity patients.

  8. Tactile spatial acuity is reduced by skin stretch at the human wrist.

    PubMed

    Cody, Frederick W J; Idrees, Raheel; Spilioti, Diamantina X; Poliakoff, Ellen

    2010-10-22

    The skin is an elastic organ that is continuously distorted as our limbs move. The hypothesis that the precision of human tactile localisation is reduced when the skin is stretched, with concurrent expansion of receptive fields (RFs) was tested. Locognosic acuity over the dorsal wrist area was quantified during application of background stretch by (a) Wrist-Bend (skin stretch combined with non-cutaneous proprioceptor activation) and (b) Skin-Pull (skin stretch alone). Participants identified the perceived direction (distal or proximal) of brief test stimuli, applied along a 7-point linear array, relative to a central reference locus. Performance was significantly reduced during the large amplitude compared to the small amplitude of tonic skin stretch, but there was no effect of stretch mode (Wrist-Bend, Skin-Pull), nor was the effect of stretch amplitude modulated by the mode of stretch. Locognosic acuity was poorer than baseline accuracy for the large amplitude skin stretches, for both application modes, but did not differ significantly from baseline for either of the small amplitude stretches. We interpret these observations as corroborating the long-held assumption that tactile localisation is primarily dependent upon the RF dimensions, and associated innervation densities, of regional touch units. The finding that performance was reduced to a similar extent under Skin-Pull and Wrist-Bend conditions suggests that non-cutaneous proprioceptors had rather little tonic modulatory effect.

  9. Binocular depth acuity research to support the modular multi-spectral stereoscopic night vision goggle

    NASA Astrophysics Data System (ADS)

    Merritt, John O.; CuQlock-Knopp, V. Grayson; Paicopolis, Peter; Smoot, Jennifer; Kregel, Mark; Corona, Bernard

    2006-05-01

    This paper discusses the depth acuity research conducted in support of the development of a Modular Multi-Spectral Stereoscopic (M2S2) night vision goggle (NVG), a customizable goggle that lets the user select one of five goggle configurations: monocular thermal, monocular image intensifier (I2), binocular I2, binocular thermal, and binocular dual-waveband (thermal imagery to one eye and I2 imagery to the other eye). The motives for the development of this type of customizable goggle were (1) the need for an NVG that allows the simultaneous use of two wavebands, (2) the need for an alternative sensor fusion method to avoid the potential image degradation that may accompany digitally fused images, (3) a requirement to provide the observer with stereoscopic, dual spectrum views of a scene, and (4) the need to handle individual user preferences for sensor types and ocular configurations employed in various military operations. Among the increases in functionality that the user will have with this system is the ability to convert from a binocular I2 device (needed for detailed terrain analysis during off-road mobility) to a monocular thermal device (for increased situational awareness in the unaided eye during nights with full moon illumination). Results of the present research revealed potential depth acuity advantages that may apply to off-road terrain hazard detection for the binocular thermal configuration. The results also indicated that additional studies are needed to address ways to minimize binocular incompatibility for the dual waveband configuration.

  10. So close: remaining challenges to eradicating polio.

    PubMed

    Toole, Michael J

    2016-03-14

    The Global Polio Eradication Initiative, launched in 1988, is close to achieving its goal. In 2015, reported cases of wild poliovirus were limited to just two countries - Afghanistan and Pakistan. Africa has been polio-free for more than 18 months. Remaining barriers to global eradication include insecurity in areas such as Northwest Pakistan and Eastern and Southern Afghanistan, where polio cases continue to be reported. Hostility to vaccination is either based on extreme ideologies, such as in Pakistan, vaccination fatigue by parents whose children have received more than 15 doses, and misunderstandings about the vaccine's safety and effectiveness such as in Ukraine. A further challenge is continued circulation of vaccine-derived poliovirus in populations with low immunity, with 28 cases reported in 2015 in countries as diverse as Madagascar, Ukraine, Laos, and Myanmar. This paper summarizes the current epidemiology of wild and vaccine-derived poliovirus, and describes the remaining challenges to eradication and innovative approaches being taken to overcome them.

  11. Decomposition Technique for Remaining Useful Life Prediction

    NASA Technical Reports Server (NTRS)

    Saha, Bhaskar (Inventor); Goebel, Kai F. (Inventor); Saxena, Abhinav (Inventor); Celaya, Jose R. (Inventor)

    2014-01-01

    The prognostic tool disclosed here decomposes the problem of estimating the remaining useful life (RUL) of a component or sub-system into two separate regression problems: the feature-to-damage mapping and the operational conditions-to-damage-rate mapping. These maps are initially generated in off-line mode. One or more regression algorithms are used to generate each of these maps from measurements (and features derived from these), operational conditions, and ground truth information. This decomposition technique allows for the explicit quantification and management of different sources of uncertainty present in the process. Next, the maps are used in an on-line mode where run-time data (sensor measurements and operational conditions) are used in conjunction with the maps generated in off-line mode to estimate both current damage state as well as future damage accumulation. Remaining life is computed by subtracting the instance when the extrapolated damage reaches the failure threshold from the instance when the prediction is made.

  12. Shotgun microbial profiling of fossil remains.

    PubMed

    Der Sarkissian, C; Ermini, L; Jónsson, H; Alekseev, A N; Crubezy, E; Shapiro, B; Orlando, L

    2014-04-01

    Millions to billions of DNA sequences can now be generated from ancient skeletal remains thanks to the massive throughput of next-generation sequencing platforms. Except in cases of exceptional endogenous DNA preservation, most of the sequences isolated from fossil material do not originate from the specimen of interest, but instead reflect environmental organisms that colonized the specimen after death. Here, we characterize the microbial diversity recovered from seven c. 200- to 13 000-year-old horse bones collected from northern Siberia. We use a robust, taxonomy-based assignment approach to identify the microorganisms present in ancient DNA extracts and quantify their relative abundance. Our results suggest that molecular preservation niches exist within ancient samples that can potentially be used to characterize the environments from which the remains are recovered. In addition, microbial community profiling of the seven specimens revealed site-specific environmental signatures. These microbial communities appear to comprise mainly organisms that colonized the fossils recently. Our approach significantly extends the amount of useful data that can be recovered from ancient specimens using a shotgun sequencing approach. In future, it may be possible to correlate, for example, the accumulation of postmortem DNA damage with the presence and/or abundance of particular microbes.

  13. Some remaining problems in HCDA analysis. [LMFBR

    SciTech Connect

    Chang, Y.W.

    1981-01-01

    The safety assessment and licensing of liquid-metal fast breeder reactors (LMFBRs) requires an analysis on the capability of the reactor primary system to sustain the consequences of a hypothetical core-disruptive accident (HCDA). Although computational methods and computer programs developed for HCDA analyses can predict reasonably well the response of the primary containment system, and follow up the phenomena of HCDA from the start of excursion to the time of dynamic equilibrium in the system, there remain areas in the HCDA analysis that merit further analytical and experimental studies. These are the analysis of fluid impact on reactor cover, three-dimensional analysis, the treatment of the perforated plates, material properties under high strain rates and under high temperatures, the treatment of multifield flows, and the treatment of prestressed concrete reactor vessels. The purpose of this paper is to discuss the structural mechanics of HCDA analysis in these areas where improvements are needed.

  14. Does hypertension remain after kidney transplantation?

    PubMed

    Pourmand, Gholamreza; Dehghani, Sanaz; Rahmati, Mohamad Reza; Mehrsai, Abdolrasoul; Gooran, Shahram; Alizadeh, Farimah; Khaki, Siavash; Mortazavi, Seyede Hamideh; Pourmand, Naghmeh

    2015-01-01

    Hypertension is a common complication of kidney transplantation with the prevalence of 80%. Studies in adults have shown a high prevalence of hypertension (HTN) in the first three months of transplantation while this rate is reduced to 50- 60% at the end of the first year. HTN remains as a major risk factor for cardiovascular diseases, lower graft survival rates and poor function of transplanted kidney in adults and children. In this retrospective study, medical records of 400 kidney transplantation patients of Sina Hospital were evaluated. Patients were followed monthly for the 1st year, every two months in the 2nd year and every three months after that. In this study 244 (61%) patients were male. Mean ± SD age of recipients was 39.3 ± 13.8 years. In most patients (40.8%) the cause of end-stage renal disease (ESRD) was unknown followed by HTN (26.3%). A total of 166 (41.5%) patients had been hypertensive before transplantation and 234 (58.5%) had normal blood pressure. Among these 234 individuals, 94 (40.2%) developed post-transplantation HTN. On the other hand, among 166 pre-transplant hypertensive patients, 86 patients (56.8%) remained hypertensive after transplantation. Totally 180 (45%) patients had post-transplantation HTN and 220 patients (55%) didn't develop HTN. Based on the findings, the incidence of post-transplantation hypertension is high, and kidney transplantation does not lead to remission of hypertension. On the other hand, hypertension is one of the main causes of ESRD. Thus, early screening of hypertension can prevent kidney damage and reduce further problems in renal transplant recipients.

  15. Improvement of tactile roughness discrimination acuity correlates with perception of improved hand function in patients after hand surgery.

    PubMed

    Fujimoto, Shuhei; Kon, Noriko

    2016-04-01

    [Purpose] The purpose of this study was to elucidate how well patients' perceptions related to the improvements in their hand function during hospitalization. [Subjects] Sixteen patients who were hospitalized after hand surgery. [Methods] Using the Japanese Society for Surgery of the Hand edition of the Quick-Disabilities of the Arm, Shoulder, and Hand questionnaire; tactile roughness discrimination acuity, motor imagery, motor function, sensory function, and pain of the upper limb were assessed at admission and discharge. Spearman's rank-order correlation coefficients were calculated using the differences in all assessment items at admission and discharge. A multiple regression analysis (stepwise method) was performed to investigate factors that correlated with improvements in Quick-Disabilities of the Arm, Shoulder, and Hand scores. [Results] The improvement of tactile roughness discrimination acuity was significantly associated with patient perception of improved hand function. [Conclusion] The results suggest that an improvement in tactile roughness discrimination acuity was most strongly correlated with patient perception of improved hand function.

  16. Development of Proprioceptive Acuity in Typically Developing Children: Normative Data on Forearm Position Sense

    PubMed Central

    Holst-Wolf, Jessica M.; Yeh, I-Ling; Konczak, Jürgen

    2016-01-01

    This study mapped the development of proprioception in healthy, typically developing children by objectively measuring forearm position sense acuity. We assessed position sense acuity in a cross-sectional sample of 308 children (5–17 years old; M/F = 127/181) and a reference group of 26 healthy adults (18–25 years old; M/F = 12/14) using a body-scalable bimanual manipulandum that allowed forearm flexion/extension in the horizontal plane. The non-dominant forearm was passively displaced to one of three target positions. Then participants actively matched the target limb position with their dominant forearm. Each of three positions was matched five times. Position error (PE), calculated as the mean difference between the angular positions of the matching and reference arms, measured position sense bias or systematic error. The respective standard deviation of the differences between the match and reference arm angular positions (SDPdiff) indicated position sense precision or random error. The main results are as follows: First, systematic error, measured by PE, did not change significantly from early childhood to late adolescence (Median PE at 90° target: −2.85° in early childhood; −2.28° in adolescence; and 1.30° in adults). Second, response variability as measured by SDPdiff significantly decreased with age (Median SDPdiff at 90° target: 9.66° in early childhood; 5.30° in late adolescence; and 3.97° in adults). The data of this large cross-sectional sample of children document that proprioceptive development in typically developing children is characterized as an age-related improvement in precision, not as a development or change in bias. In other words, it is the reliability of the perceptual response that improves between early childhood and adulthood. This study provides normative data against which position sense acuity in pediatric patient populations can be compared. The underlying neurophysiological processes that could explain the observed

  17. Development of Proprioceptive Acuity in Typically Developing Children: Normative Data on Forearm Position Sense.

    PubMed

    Holst-Wolf, Jessica M; Yeh, I-Ling; Konczak, Jürgen

    2016-01-01

    This study mapped the development of proprioception in healthy, typically developing children by objectively measuring forearm position sense acuity. We assessed position sense acuity in a cross-sectional sample of 308 children (5-17 years old; M/F = 127/181) and a reference group of 26 healthy adults (18-25 years old; M/F = 12/14) using a body-scalable bimanual manipulandum that allowed forearm flexion/extension in the horizontal plane. The non-dominant forearm was passively displaced to one of three target positions. Then participants actively matched the target limb position with their dominant forearm. Each of three positions was matched five times. Position error (PE), calculated as the mean difference between the angular positions of the matching and reference arms, measured position sense bias or systematic error. The respective standard deviation of the differences between the match and reference arm angular positions (SDPdiff) indicated position sense precision or random error. The main results are as follows: First, systematic error, measured by PE, did not change significantly from early childhood to late adolescence (Median PE at 90° target: -2.85° in early childhood; -2.28° in adolescence; and 1.30° in adults). Second, response variability as measured by SDPdiff significantly decreased with age (Median SDPdiff at 90° target: 9.66° in early childhood; 5.30° in late adolescence; and 3.97° in adults). The data of this large cross-sectional sample of children document that proprioceptive development in typically developing children is characterized as an age-related improvement in precision, not as a development or change in bias. In other words, it is the reliability of the perceptual response that improves between early childhood and adulthood. This study provides normative data against which position sense acuity in pediatric patient populations can be compared. The underlying neurophysiological processes that could explain the observed

  18. Smart Point Cloud: Definition and Remaining Challenges

    NASA Astrophysics Data System (ADS)

    Poux, F.; Hallot, P.; Neuville, R.; Billen, R.

    2016-10-01

    Dealing with coloured point cloud acquired from terrestrial laser scanner, this paper identifies remaining challenges for a new data structure: the smart point cloud. This concept arises with the statement that massive and discretized spatial information from active remote sensing technology is often underused due to data mining limitations. The generalisation of point cloud data associated with the heterogeneity and temporality of such datasets is the main issue regarding structure, segmentation, classification, and interaction for an immediate understanding. We propose to use both point cloud properties and human knowledge through machine learning to rapidly extract pertinent information, using user-centered information (smart data) rather than raw data. A review of feature detection, machine learning frameworks and database systems indexed both for mining queries and data visualisation is studied. Based on existing approaches, we propose a new 3-block flexible framework around device expertise, analytic expertise and domain base reflexion. This contribution serves as the first step for the realisation of a comprehensive smart point cloud data structure.

  19. Organic Remains in Finnish Subglacial Sediments

    NASA Astrophysics Data System (ADS)

    Punkari, Mikko; Forsström, Lars

    1995-05-01

    Many sites in Fennoscandia contain pre-Late Weichselian beds of organic matter, located mostly in the flanks of eskers. It is a matter of debate whether these fragmentary beds were deposited in situ, or whether they were deposited elsewhere and then picked up and moved by glacial ice. The till-mantled esker of Harrinkangas includes a shallow depression filled with sand and silt containing, for example, several tightly packed laminar sheets of brown moss ( Bryales) remains. It is argued that these thin peat sheets were transported at the base of the ice sheet, or englacially, and were deposited together with the silt and sand on the side of a subglacial meltwater tunnel. Subglacial meltout till subsequently covered the flanks of the esker near the receding ice margin. Information about the depositional and climatic environments was obtained from biostratigraphic analysis of the organic matter. Pollen spectra for the peat represent an open birch forest close to the tundra zone. A thin diamicton beneath the peat contains charred pine wood, recording the former presence of pine forests in western Finland. The unhumified, extremely well-preserved peat evidently originated during the final phase of an ice-free period, most probably the end of the Eemian Interglaciation. It was redeposited in the esker by the last ice sheet. Reconstructions of the Pleistocene chronology and stratigraphy of central Fennoscandia that rely on such redeposited organic matter should be viewed with caution.

  20. Spatial patterning of vulture scavenged human remains.

    PubMed

    Spradley, M Katherine; Hamilton, Michelle D; Giordano, Alberto

    2012-06-10

    This article presents the results of a pilot study on the effects of vulture modification to human remains. A donated body from the Willed Body Donation Program was placed at the Forensic Anthropology Research Facility (FARF), an outdoor human decomposition laboratory located at Texas State University-San Marcos. The effects of vulture scavenging on the timing and sequence, and the rate of skeletonization, disarticulation, and dispersal were observed via a motion sensing camera and direct observation. Using GIS (Geographic Information Systems) and GPS (Global Positioning System) technologies and spatial analytical methods, the transport of skeletal elements was mapped in order to analyze dispersal and terrain-influenced patterns of active vulture scavenging. Results showed that the initial scavenging took place 37 days after placement at FARF. This delay in scavenging differs from previous research. After the initial appearance of the vultures, the body was reduced from a fully-fleshed individual to a skeleton within only 5h. This underscores the potential for errors in postmortem interval estimations made at vulture scavenged scenes. Additionally, spatial analysis showed that skeletal elements were dispersed by vultures to lower elevations, and that the disarticulation and dispersal of the skeletal elements occurs early in the scavenging sequence.

  1. Ghost Remains After Black Hole Eruption

    NASA Astrophysics Data System (ADS)

    2009-05-01

    NASA's Chandra X-ray Observatory has found a cosmic "ghost" lurking around a distant supermassive black hole. This is the first detection of such a high-energy apparition, and scientists think it is evidence of a huge eruption produced by the black hole. This discovery presents astronomers with a valuable opportunity to observe phenomena that occurred when the Universe was very young. The X-ray ghost, so-called because a diffuse X-ray source has remained after other radiation from the outburst has died away, is in the Chandra Deep Field-North, one of the deepest X-ray images ever taken. The source, a.k.a. HDF 130, is over 10 billion light years away and existed at a time 3 billion years after the Big Bang, when galaxies and black holes were forming at a high rate. "We'd seen this fuzzy object a few years ago, but didn't realize until now that we were seeing a ghost", said Andy Fabian of the Cambridge University in the United Kingdom. "It's not out there to haunt us, rather it's telling us something - in this case what was happening in this galaxy billions of year ago." Fabian and colleagues think the X-ray glow from HDF 130 is evidence for a powerful outburst from its central black hole in the form of jets of energetic particles traveling at almost the speed of light. When the eruption was ongoing, it produced prodigious amounts of radio and X-radiation, but after several million years, the radio signal faded from view as the electrons radiated away their energy. HDF 130 Chandra X-ray Image of HDF 130 However, less energetic electrons can still produce X-rays by interacting with the pervasive sea of photons remaining from the Big Bang - the cosmic background radiation. Collisions between these electrons and the background photons can impart enough energy to the photons to boost them into the X-ray energy band. This process produces an extended X-ray source that lasts for another 30 million years or so. "This ghost tells us about the black hole's eruption long after

  2. Dynamic Visual Acuity While Walking in Normals and Labyrinthine-Deficient Patients

    NASA Technical Reports Server (NTRS)

    Hillman, Edward J.; Bloomberg, Jacob J.; McDonald, P. Vernon; Cohen, Helen S.

    1996-01-01

    We describe a new, objective, easily administered test of dynamic visual acuity (DVA) while walking. Ten normal subjects and five patients with histories of severe bilateral vestibular dysfunctions participated in this study. Subjects viewed a visual display of numerals of different font sizes presented on a laptop computer while they stood still and while they walked on a motorized treadmill. Treadmill speed was adapted for 4 of 5 patients. Subjects were asked to identify the numerals as they appeared on the computer screen. Test results were reasonably repeatable in normals. The percent correct responses at each font size dropped slightly while walking in normals and dropped significantly more in patients. Patients performed significantly worse than normals while standing still and while walking. This task may be useful for evaluating post-flight astronauts and vestibularly impaired patients.

  3. Impaired acuity of the approximate number system underlies mathematical learning disability (dyscalculia).

    PubMed

    Mazzocco, Michèle M M; Feigenson, Lisa; Halberda, Justin

    2011-01-01

    Many children have significant mathematical learning disabilities (MLD, or dyscalculia) despite adequate schooling. The current study hypothesizes that MLD partly results from a deficiency in the Approximate Number System (ANS) that supports nonverbal numerical representations across species and throughout development. In this study of 71 ninth graders, it is shown that students with MLD have significantly poorer ANS precision than students in all other mathematics achievement groups (low, typically, and high achieving), as measured by psychophysical assessments of ANS acuity (w) and of the mappings between ANS representations and number words (cv). This relation persists even when controlling for domain-general abilities. Furthermore, this ANS precision does not differentiate low-achieving from typically achieving students, suggesting an ANS deficit that is specific to MLD.

  4. [Laser pointers are not toys; eye injury with permanent loss of visual acuity].

    PubMed

    Keunen, Jan E E; Delbecq, Ann-Laure M H; Cruysberg, J R M Hans; van Meurs, Jan C; Gan, Ivan M; Berendschot, Tos T J M

    2014-01-01

    In the nineteen-nineties, there was much hype in the European media about presumed laser pointer maculopathy. However, the recent introduction of more powerful and therefore more dangerous laser pointers and their easy availability on the internet necessitates vigilance on the issue. This is an urgent matter, as here we report three cases of proven maculopathy due to an unsafe laser pointer. Three boys aged 13, 9 and 12 years used an unsafe laser pointer as a toy and looked repeatedly into the pointer, resulting in a permanent reduction in visual acuity due to macular damage. Laser pointers are not designed to be children's toys or instruments to annoy people in a crowd. Health authorities and the ophthalmic community should be aware of the potential danger of improper use of high-output laser pointers and warn the general public before the widespread availability of unsafe laser pointers and consequently laser pointer-induced macular damage becomes a true social problem.

  5. The Amelioration of Olfactory Acuity upon Sexual Maturation Might Affect Food Preferences

    PubMed Central

    Bignetti, Enrico; Sinesio, Fiorella; Aiello, Gaetano L.; Cannella, Carlo

    2009-01-01

    Upon sexual maturation, olfactory acuity in women ameliorates and starts oscillating across the cycle. During ovulation, mean olfactory threshold is 30 times lower than during bleeding. Interestingly, menstruated women undergo maleodorant trimethylaminuria. We argued that olfactory amelioration during ovulation might concur to a mating strategy, whereas olfactory impairment during bleeding might protect women against self-refusal. Testosterone and its 17β-estradiol derivative might be responsible for the synchronization of these menstrual events. Furthermore, we posed the question whether olfactory detection amelioration upon sexual maturation might provoke a change in food preferences, for instance a reduction in fish consumption. A preliminary survey in Italy provided encouraging results: 15-44 year-old women have lower fish consumption than 3-14 year-old girls. Surprisingly, men exhibited the same behaviour, so new olfactory tests as well as testosterone measurements are under way. PMID:22253964

  6. Absolute Pitch—Functional Evidence of Speech-Relevant Auditory Acuity

    PubMed Central

    Oechslin, Mathias S.; Meyer, Martin

    2010-01-01

    Absolute pitch (AP) has been shown to be associated with morphological changes and neurophysiological adaptations in the planum temporale, a cortical area involved in higher-order auditory and speech perception processes. The direct link between speech processing and AP has hitherto not been addressed. We provide first evidence that AP compared with relative pitch (RP) ability is associated with significantly different hemodynamic responses to complex speech sounds. By systematically varying the lexical and/or prosodic information of speech stimuli, we demonstrated consistent activation differences in AP musicians compared with RP musicians and nonmusicians. These differences relate to stronger activations in the posterior part of the middle temporal gyrus and weaker activations in the anterior mid-part of the superior temporal gyrus. Furthermore, this pattern is considerably modulated by the auditory acuity of AP. Our results suggest that the neural underpinnings of pitch processing expertise exercise a strong influence on propositional speech perception (sentence meaning). PMID:19592570

  7. Proprioceptive acuity assessment via joint position matching: from basic science to general practice.

    PubMed

    Goble, Daniel J

    2010-08-01

    Over the past several decades, studies of use-dependent plasticity have demonstrated a critical role for proprioceptive feedback in the reorganization, and subsequent recovery, of neuromotor systems. As such, an increasing emphasis has been placed on tests of proprioceptive acuity in both the clinic and the laboratory. One test that has garnered particular interest is joint position matching, whereby individuals must replicate a reference joint angle in the absence of vision (ie, using proprioceptive information). On the surface, this test might seem straightforward in nature. However, the present perspective article informs therapists and researchers alike of multiple insights gained from a recent series of position matching studies by the author and colleagues. In particular, 5 factors are outlined that can assist clinicians in developing well-informed opinions regarding the outcomes of tests of position matching abilities. This information should allow for enhanced diagnosis of proprioceptive deficits within clinical settings in the future.

  8. The Use of Dynamic Visual Acuity as a Functional Test of Gaze Stabilization Following Space Flight

    NASA Technical Reports Server (NTRS)

    Peters, B. T.; Mulavara, A. P.; Brady, R.; Miller, C. A.; Richards, J. T.; Warren, L. E.; Cohen, H. S.; Bloomberg, J. J.

    2006-01-01

    After prolonged exposure to a given gravitational environment the transition to another is accompanied by adaptations in the sensorimotor subsystems, including the vestibular system. Variation in the adaptation time course of these subsystems, and the functional redundancies that exist between them make it difficult to accurately assess the functional capacity and physical limitations of astro/cosmonauts using tests on individual subsystems. While isolated tests of subsystem performance may be the only means to address where interventions are required, direct measures of performance may be more suitable for assessing the operational consequences of incomplete adaptation to changes in the gravitational environment. A test of dynamic visual acuity (DVA) is currently being used in the JSC Neurosciences Laboratory as part of a series of measures to assess the efficacy of a countermeasure to mitigate postflight locomotor dysfunction. In the current protocol, subjects visual acuity is determined using Landolt ring optotypes presented sequentially on a computer display. Visual acuity assessments are made both while standing and while walking at 1.8 m/s on a motorized treadmill. The use of a psychophysical threshold detection algorithm reduces the required number of optotype presentations and the results can be presented immediately after the test. The difference between the walking and standing acuity measures provides a metric of the change in the subject s ability to maintain gaze fixation on the visual target while walking. This functional consequence is observable regardless of the underlying subsystem most responsible for the change. Data from 15 cosmo/astronauts have been collected following long-duration (approx. 6 months) stays in space using a visual target viewing distance of 4.0 meters. An investigation of the group mean shows a change in DVA soon after the flight that asymptotes back to baseline approximately one week following their return to earth. The

  9. Pain sensitivity and tactile spatial acuity are altered in healthy musicians as in chronic pain patients

    PubMed Central

    Zamorano, Anna M.; Riquelme, Inmaculada; Kleber, Boris; Altenmüller, Eckart; Hatem, Samar M.; Montoya, Pedro

    2015-01-01

    Extensive training of repetitive and highly skilled movements, as it occurs in professional classical musicians, may lead to changes in tactile sensitivity and corresponding cortical reorganization of somatosensory cortices. It is also known that professional musicians frequently experience musculoskeletal pain and pain-related symptoms during their careers. The present study aimed at understanding the complex interaction between chronic pain and music training with respect to somatosensory processing. For this purpose, tactile thresholds (mechanical detection, grating orientation, two-point discrimination) and subjective ratings to thermal and pressure pain stimuli were assessed in 17 professional musicians with chronic pain, 30 pain-free musicians, 20 non-musicians with chronic pain, and 18 pain-free non-musicians. We found that pain-free musicians displayed greater touch sensitivity (i.e., lower mechanical detection thresholds), lower tactile spatial acuity (i.e., higher grating orientation thresholds) and increased pain sensitivity to pressure and heat compared to pain-free non-musicians. Moreover, we also found that musicians and non-musicians with chronic pain presented lower tactile spatial acuity and increased pain sensitivity to pressure and heat compared to pain-free non-musicians. The significant increment of pain sensitivity together with decreased spatial discrimination in pain-free musicians and the similarity of results found in chronic pain patients, suggests that the extensive training of repetitive and highly skilled movements in classical musicians could be considered as a risk factor for developing chronic pain, probably due to use-dependent plastic changes elicited in somatosensory pathways. PMID:25610384

  10. Contrast visual acuity in patients with retinitis pigmentosa assessed by a contrast sensitivity tester

    PubMed Central

    Oishi, Maho; Nakamura, Hajime; Hangai, Masanori; Oishi, Akio; Otani, Atsushi; Yoshimura, Nagahisa

    2012-01-01

    Purpose: To assess contrast visual acuity (CVA) in patients with retinitis pigmentosa (RP) and compare the result with standard visual acuity (VA), retinal thickness, status of inner segment/outer segment junction, and central visual field. Materials and Methods: Thirty-nine eyes of 39 patients with RP and 39 eyes of 39 healthy individuals were studied. To see the difference in CVA between RP patients and normal controls, only subjects with standard VA of 1.0 (20/20) or better were included. This was a cross-sectional study. CVA in various light conditions was measured with CAT-2000 and was compared between patients and controls. CVA of patients was further analyzed for association with other parameters including foveal retinal thickness, outer nuclear layer thickness, the status of inner segment/outer segment junction measured with optical coherence tomography (OCT), and visual field mean deviation (MD) measured with Humphrey field analyzer 10-2 program. Results: CVA impairment was evident in RP patients compared to controls (P < 0.01, in all measurement conditions). Multivariate analysis showed association of logarithm of the minimum angle of resolution (logMAR) with CVAs in several conditions. None of the OCT measurements was associated with CVA. When patients were divided into three groups based on MD, the most advanced group (MD worse than or equal to –20 dB) showed impairment of mesopic CVA (P < 0.05, under mesopic condition of 100% without glare, with glare, and 25% without glare). Conclusion: CVA impairment was confirmed in RP patients, especially in advanced cases. CVA measured with CAT-2000 may be a useful tool for assessing foveal function in RP patients. PMID:23202395

  11. Compensatory responses to age-related decline in odor quality acuity: cholinergic neuromodulation and olfactory enrichment.

    PubMed

    Mandairon, Nathalie; Peace, Shane T; Boudadi, Karim; Boxhorn, Christine E; Narla, Venkata Anupama; Suffis, Sara D; Cleland, Thomas A

    2011-12-01

    The perceptual differentiation of odors can be measured behaviorally using generalization gradients. The steepness of these gradients defines a form of olfactory acuity for odor quality that depends on neural circuitry within the olfactory bulb and is regulated by cholinergic activity therein as well as by associative learning. Using this system as a reduced model for age-related cognitive decline, we show that aged mice, while maintaining almost the same baseline behavioral performance as younger mice, are insensitive to the effects of acutely elevated acetylcholine, which sharpens generalization gradients in young adult mice. Moreover, older mice exhibit evidence of chronically elevated acetylcholine levels in the olfactory bulb, suggesting that their insensitivity to further elevated levels of acetylcholine may arise because the maximum capacity of the system to respond to acetylcholine has already been reached. We propose a model in which an underlying, age-related, progressive deficit is mitigated by a compensatory cholinergic feedback loop that acts to retard the behavioral effects of what would otherwise be a substantial age-related decline in olfactory plasticity. We also treated mice with 10-day regimens of olfactory environmental enrichment and/or repeated systemic injections of the acetylcholinesterase inhibitor physostigmine. Each treatment alone sharpened odor quality acuity, but administering both treatments together had no greater effect than either alone. Age was not a significant main effect in this study, suggesting that some capacity for acetylcholine-dependent plasticity is still present in aged mice despite their sharply reduced ability to respond to acute increases in acetylcholine levels. These results suggest a dynamical framework for understanding age-related decline in neural circuit processing in which the direct effects of aging can be mitigated, at least temporarily, by systemic compensatory responses. In particular, a decline in

  12. Slanted joint axes of the stick insect antenna: an adaptation to tactile acuity

    NASA Astrophysics Data System (ADS)

    Mujagic, Samir; Krause, André F.; Dürr, Volker

    2007-04-01

    Like many flightless, obligatory walking insects, the stick insect Carausius morosus makes intensive use of active antennal movements for tactile near range exploration and orientation. The antennal joints of C. morosus have a peculiar oblique and non-orthogonal joint axis arrangement. Moreover, this arrangement is known to differ from that in crickets (Ensifera), locusts (Caelifera) and cockroaches (Blattodea), all of which have an orthogonal joint axis arrangement. Our hypothesis was that the situation found in C. morosus represents an important evolutionary trait of the order of stick and leaf insects (Phasmatodea). If this was true, it should be common to other species of the Phasmatodea. The objective of this comparative study was to resolve this question. We have measured the joint axis orientation of the head scape and scape pedicel joints along with other parameters that affect the tactile efficiency of the antenna. The obtained result was a complete kinematic description of the antenna. This was used to determine the size and location of kinematic out-of-reach zones, which are indicators of tactile acuity. We show that the oblique and non-orthogonal arrangement is common to eight species from six sub-families indicating that it is a synapomorphic character of the Euphasmatodea. This character can improve tactile acuity compared to the situation in crickets, locusts and cockroaches. Finally, because molecular data of a recent study indicate that the Phasmatodea may have evolved as flightless, obligatory walkers, we argue that the antennal joint axis arrangement of the Euphasmatodea reflects an evolutionary adaptation to tactile near range exploration during terrestrial locomotion.

  13. Ciguatera: recent advances but the risk remains.

    PubMed

    Lehane, L; Lewis, R J

    2000-11-01

    Ciguatera is an important form of human poisoning caused by the consumption of seafood. The disease is characterised by gastrointestinal, neurological and cardiovascular disturbances. In cases of severe toxicity, paralysis, coma and death may occur. There is no immunity, and the toxins are cumulative. Symptoms may persist for months or years, or recur periodically. The epidemiology of ciguatera is complex and of central importance to the management and future use of marine resources. Ciguatera is an important medical entity in tropical and subtropical Pacific and Indian Ocean regions, and in the tropical Caribbean. As reef fish are increasingly exported to other areas, it has become a world health problem. The disease is under-reported and often misdiagnosed. Lipid-soluble, polyether toxins known as ciguatoxins accumulated in the muscles of certain subtropical and tropical marine finfish cause ciguatera. Ciguatoxins arise from biotransformation in the fish of less polar ciguatoxins (gambiertoxins) produced by Gambierdiscus toxicus, a marine dinoflagellate that lives on macroalgae, usually attached to dead coral. The toxins and their metabolites are concentrated in the food chain when carnivorous fish prey on smaller herbivorous fish. Humans are exposed at the end of the food chain. More than 400 species of fish can be vectors of ciguatoxins, but generally only a relatively small number of species are regularly incriminated in ciguatera. Ciguateric fish look, taste and smell normal, and detection of toxins in fish remains a problem. More than 20 precursor gambiertoxins and ciguatoxins have been identified in G. toxicus and in herbivorous and carnivorous fish. The toxins become more polar as they undergo oxidative metabolism and pass up the food chain. The main Pacific ciguatoxin (P-CTX-1) causes ciguatera at levels=0.1 microg/kg in the flesh of carnivorous fish. The main Caribbean ciguatoxin (C-CTX-1) is less polar and 10-fold less toxic than P-CTX-1. Ciguatoxins

  14. The Two Sides of Sensory–Cognitive Interactions: Effects of Age, Hearing Acuity, and Working Memory Span on Sentence Comprehension

    PubMed Central

    DeCaro, Renee; Peelle, Jonathan E.; Grossman, Murray; Wingfield, Arthur

    2016-01-01

    Reduced hearing acuity is among the most prevalent of chronic medical conditions among older adults. An experiment is reported in which comprehension of spoken sentences was tested for older adults with good hearing acuity or with a mild-to-moderate hearing loss, and young adults with age-normal hearing. Comprehension was measured by participants’ ability to determine the agent of an action in sentences that expressed this relation with a syntactically less complex subject-relative construction or a syntactically more complex object-relative construction. Agency determination was further challenged by inserting a prepositional phrase into sentences between the person performing an action and the action being performed. As a control, prepositional phrases of equivalent length were also inserted into sentences in a non-disruptive position. Effects on sentence comprehension of age, hearing acuity, prepositional phrase placement and sound level of stimulus presentations appeared only for comprehension of sentences with the more syntactically complex object-relative structures. Working memory as tested by reading span scores accounted for a significant amount of the variance in comprehension accuracy. Once working memory capacity and hearing acuity were taken into account, chronological age among the older adults contributed no further variance to comprehension accuracy. Results are discussed in terms of the positive and negative effects of sensory–cognitive interactions in comprehension of spoken sentences and lend support to a framework in which domain-general executive resources, notably verbal working memory, play a role in both linguistic and perceptual processing. PMID:26973557

  15. Visual Acuity of Youths 12-17 Years, United States. Vital and Health Statistics, Series 11, No. 127.

    ERIC Educational Resources Information Center

    Roberts, Jean; Slaby, David

    Presented are the findings of a national health examination survey of uncorrected and corrected monocular and binocular visual acuity of 7,514 noninstitutionalized youth 12 to 17 years of age analyzed with respect to age, sex, race, geographic region, size of place of residence, and annual family income. Among findings reported are that 70 0/0 of…

  16. Proprioceptive acuity predicts muscle co-contraction of the tibialis anterior and gastrocnemius medialis in older adults' dynamic postural control.

    PubMed

    Craig, C E; Goble, D J; Doumas, M

    2016-05-13

    Older adults use a different muscle strategy to cope with postural instability, in which they 'co-contract' the muscles around the ankle joint. It has been suggested that this is a compensatory response to age-related proprioceptive decline however this view has never been assessed directly. The current study investigated the association between proprioceptive acuity and muscle co-contraction in older adults. We compared muscle activity, by recording surface electromyography (EMG) from the bilateral tibialis anterior (TA) and gastrocnemius medialis (GM) muscles, in young (aged 18-34) and older adults (aged 65-82) during postural assessment on a fixed and sway-referenced surface at age-equivalent levels of sway. We performed correlations between muscle activity and proprioceptive acuity, which was assessed using an active contralateral matching task. Despite successfully inducing similar levels of sway in the two age groups, older adults still showed higher muscle co-contraction. A stepwise regression analysis showed that proprioceptive acuity measured using variable error was the best predictor of muscle co-contraction in older adults. However, despite suggestions from previous research, proprioceptive error and muscle co-contraction were negatively correlated in older adults, suggesting that better proprioceptive acuity predicts more co-contraction. Overall, these results suggest that although muscle co-contraction may be an age-specific strategy used by older adults, it is not to compensate for age-related proprioceptive deficits.

  17. The Influence of Auditory Acuity on Acoustic Variability and the Use of Motor Equivalence during Adaptation to a Perturbation

    ERIC Educational Resources Information Center

    Brunner, Jana; Ghosh, Satrajit; Hoole, Philip; Matthies, Melanie; Tiede, Mark; Perkell, Joseph

    2011-01-01

    Purpose: The aim of this study was to relate speakers' auditory acuity for the sibilant contrast, their use of motor equivalent trading relationships in producing the sibilant /[esh]/, and their produced acoustic distance between the sibilants /s/ and /[esh]/. Specifically, the study tested the hypotheses that during adaptation to a perturbation…

  18. Readers' Trust, Socio-Demographic, and Acuity Influences in Citizen Journalism Credibility for Disrupted Online Newspapers

    ERIC Educational Resources Information Center

    Wester, Aaron Micah

    2013-01-01

    The purpose of this quantitative research study was to evaluate and determine if significant associations and linear correlations exist between reader socio-demographics, levels of trust and affinity in online citizen writer news story article content, brand loyalty, and acuity in newspaper organizations transitioning from print to online in a…

  19. Brief Report: The Relationship between Visual Acuity, the Embedded Figures Test and Systemizing in Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Brosnan, Mark J.; Gwilliam, Lucy R.; Walker, Ian

    2012-01-01

    Enhanced performance upon the Embedded Figures Test (EFT) in individuals with autism spectrum disorder (ASD) has informed psychological theories of the non-social aspects that characterise ASD. The Extreme Male Brain theory of autism proposes that enhanced visual acuity underpins greater attention to detail (assessed by the EFT) which is a…

  20. Visual Function after Primary Posterior Chamber Intraocular Lens Implantation in Pediatric Unilateral Cataract: Stereopsis and Visual Acuity

    PubMed Central

    Park, Jung Hyun; Kim, Jeong Hun; Kim, Seong Joon; Choung, Ho Kyung

    2007-01-01

    Purpose To investigate the association between binocular function and vision after cataract removal and primary posterior chamber intraocular lens (PC-IOL) implantation in children with unilateral cataract and to identify visual function differences according cataract type. Methods Clinical records of 2- to 6-year-old patients with unilateral cataract removal and primary PC-IOL implantation were reviewed retrospectively. Visual acuity and ocular alignment were measured. Sensory fusion was assessed with the Worth 4-dot test, and stereoacuity with the Titmus stereo test. Cataracts were classified according to cause, lens opacity location, age at onset, and presence of strabismus. Clinical characteristics of patients who obtained good visual function were identified. Results Forty-seven patients were included. Among 22 (46.8%) with good vision (20/40 or better), only 6 (27.3%) achieved good binocular function (the presence of fusion and 100 seconds of arc or better of stereoacuity). Visual acuity was better in eyes with good binocular function (p=0.002). No other variables were significant for achieving good binocular function. Conclusions The removal of unilateral cataract in a visually immature child can result in a combination of good visual acuity and binocular function. Good binocular function is closely related to good visual acuity. PMID:18063882

  1. The level of improvement of visual acuity in high corneal astigmatism with rigid gas permeable contact lenses.

    PubMed

    Opačić, Dalibor; Miljak, Snježana; Ćuruvija-Opačić, Ksenija

    2015-03-01

    The aim of this study was to calculate the level of improvement of visual acuity comparing the best corrected visual acuity (VA) achieved with spectacles with the best corrected VA achieved with rigid gas permeable (RGP) contact lenses in patients with high, simple or compound corneal astigmatism (myopic, hypermetropic and mixed). The investigation of patients included auto-kerato-refractometry, manual keratometry, corneal topography and visual acuity with Snellen chart. The best corrected VA obtained with spectacles was compared with the best corrected VA obtained with RGP contact lenses in 72 patients (116 eyes). All patients showed a significant improvement in visual acuity with RGP lenses from one to seven lines compared to spectacles (p = 0.0001). Level of improvement in VA represented as the number of lines obtained was as follows: 74 percent of patients got two to four lines more in VA with RGP lenses compared to spectacles, and almost 10 percent of patients got five to seven lines. RGP contact lenses provide a significant improvement in VA compared to VA reached with spectacles in patients with high corneal astigmatism. The benefit in VA with RGP lenses is higher as the astigmatism is higher.

  2. The Impact of Standardized Acuity Assessment and a Fast-Track on Length of Stay in Obstetric Triage: A Quality Improvement Study.

    PubMed

    Smithson, David S; Twohey, Rachel; Watts, Nancy; Gratton, Robert J

    To prospectively assess the impact of a standardized 5-category Obstetrical Triage Acuity Scale (OTAS) and a fast-track for lower-acuity patients on patient flow. Length of stay (LOS) data of women presenting to obstetric triage were abstracted from the electronic medical record prior to (July 1, 2011, to March 30, 2012) and following OTAS implementation (April 1 to December 31, 2012). Following computerized simulation modeling, a fast-track for lower acuity women was implemented (January 1, 2013, to February 28, 2014). Prior to OTAS implementation (8085 visits), the median LOS was 105 (interquartile range [IQR] = 52-178) minutes. Following OTAS implementation (8131 visits), the median LOS decreased to 101 (IQR = 49-175) minutes (P = .04). The LOS did not correlate well with acuity. Simulation modeling predicted that a fast-track for OTAS 4 and 5 patients would reduce the LOS. The LOS for lower-acuity patients in the fast-track decreased to 73 (IQR = 40-140) minutes (P = .005). In addition, the overall LOS (12 576 visits) decreased to 98 (IQR = 47-172) minutes (6.9% reduction; P < .001). Standardized assessment of acuity and a fast-track for lower acuity pregnant women decreased the overall LOS and the LOS of lower-acuity patients.

  3. The effect of zinc deficiency on salt taste acuity, preference, and dietary sodium intake in hemodialysis patients.

    PubMed

    Kim, So Mi; Kim, Miyeon; Lee, Eun Kyoung; Kim, Soon Bae; Chang, Jai Won; Kim, Hyun Woo

    2016-07-01

    Introduction High sodium intake is the main cause of fluid overload in hemodialysis (HD) patients, leading to increased cardiovascular mortality. High sodium intake is known to be associated with low salt taste acuity and/or high preference. As the zinc status could influence taste acuity, we analyzed the effect of zinc deficiency on salt taste acuity, preference, and dietary sodium intake in HD patients. Methods A total of 77 HD patients was enrolled in this cross-sectional study. Zinc deficiency was defined as serum zinc level with below 70 µg/mL. The patients were divided into two groups based on serum zinc level. Salt taste acuity and preference were determined by a sensory test using varying concentrations of NaCl solution, and dietary sodium intake was estimated using 3-day dietary recall surveys. Findings The mean salt recognition threshold and salt taste preference were significantly higher in the zinc deficient group than in the non-zinc deficient group. And there was significant positive correlation between salt taste preference and dietary sodium intake in zinc deficient group (r = 0.43, P = 0.002). Although, the dietary sodium intake showed a high tendency with no significance (P = 0.052), interdialytic weight gain was significantly higher in the zinc deficient group than in the non-zinc deficient group (2.68 ± 1.02 kg vs. 3.18 ± 1.02 kg; P = 0.047). Discussion Zinc deficiency may be related to low salt taste acuity and high salt preference, leading to high dietary sodium intake in HD patients.

  4. A comparison of visual acuity, predictability, and visual function outcomes after intracorneal ring segments and laser in situ keratomileusis.

    PubMed Central

    Suiter, B G; Twa, M D; Ruckhofer, J; Schanzlin, D J

    2000-01-01

    PURPOSE: To compare correction of low myopia by intrastromal corneal ring segments (ICRS) and by laser in situ keratomileusis (LASIK) with respect to early visual recovery and refractive outcomes. METHODS: Eighty-two eyes implanted with ICRS in a phase III study for US Food and Drug Administration review were matched with 133 eyes treated with LASIK by criteria of age (> 18 years, < 65 years), preoperative myopia (-1.00 to -3.50 diopters [D]), astigmatism (< or = 1.00 D), single treatment, and attempted full correction. Examinations were performed preoperatively and postoperatively at days 1 and 7 and months 1 and 3. Visual acuity and manifest refraction data were collected retrospectively. Visual function scores were assigned, and summarized results were compared. RESULTS: Uncorrected visual acuity was 20/20 or better at day 1 in 24% of eyes (20/82) after ICRS and in 55% of eyes (73/133) after LASIK, and at month 3 in 75% of eyes (58/77) after ICRS and in 67% of eyes (84/126) after LASIK. Spherical equivalent refraction at month 3 was within +/- 1.00 D of intended correction in 99% of eyes (76/77) after ICRS and in 96% of eyes (121/126) after LASIK. Excellent visual function scores were noted at month 3 in 90% of eyes (69/77) after ICRS and in 78% of eyes (98/126) after LASIK. CONCLUSION: Patients treated with LASIK showed better uncorrected visual acuity immediately following surgery; however, beyond 1 month, patients treated with ICRS achieved better uncorrected visual acuity that continued to improve with time. Visual function scores indicate that ICRS eyes see at higher levels of uncorrected visual acuity than LASIK eyes do with the same refractive error. The ICRS and LASIK were comparable in the correction of mild myopia. PMID:11190040

  5. A randomised comparison between an inexpensive, general-purpose headlight and a purpose-built surgical headlight on users' visual acuity and colour vision.

    PubMed

    Street, I; Sayles, M; Nistor, M; McRae, A R

    2014-02-01

    To determine if there are any differences in near visual acuity and colour vision between an inexpensive general-purpose light emitting diode (LED) headlight and a purpose-built surgical LED headlight. A prospective study was conducted sequentially comparing near visual acuity and colour vision, the headlights being tested in random order, in a testing room with a constant minimal amount of background light. The participants were NHS employee volunteers, with self-declared normal (or corrected) vision, working in occupations requiring full literacy. For visual acuity, outcome was measured by recording the smallest font legible when using each headlight when the subject read a near visual acuity test card. For colour vision, the outcome was passing or failing the Ishihara test. There was no statistically significant difference between the general-purpose and the purpose-built headlights in users' near visual acuity or colour vision.

  6. Development of a Reading Accessibility Index Using the MNREAD Acuity Chart

    PubMed Central

    Calabrèse, Aurélie; Owsley, Cynthia; McGwin, Gerald; Legge, Gordon E.

    2017-01-01

    IMPORTANCE We define a Reading Accessibility Index for evaluating reading in individuals with normal and low vision. OBJECTIVE To compare the Reading Accessibility Index with data from the Impact of Cataracts on Mobility (ICOM) study. DESIGN, SETTING, AND PARTICIPANTS This investigation was a secondary data analysis from the ICOM study performed between July 1, 2014, and September 20, 2015, at 12 eye clinics in Alabama from October 1, 1994, through March 31, 1996. Participants were 321 adults with cataract (n = 92), pseudophakia (n = 131), or natural crystalline lenses without cataract (n = 98). MAIN OUTCOMES AND MEASURES The Reading Accessibility Index (hereafter referred to using the abbreviation ACC for the first 3 letters of Accessibility) is defined as an individual’s mean reading speed measured across the 10 largest print sizes on the MNREAD Acuity Chart (Precision Vision) (0.4–1.3 logarithm of the minimum angle of resolution at 40 cm), normalized by 200 words per minute, which was the mean value for a group of 365 normally sighted young adults. The ACC is a single-value measure that captures an individual’s range of accessible print sizes and reading fluency within this range. RESULTS The study cohort comprised 321 participants. Their age range was 55 to 85 years, and 157 (48.9%) were female. The ACCs for the ICOM study participants ranged from 0.19 to 1.33, where 1.00 is the mean value for normally sighted young adults. The ACC for the cataract group (mean [SD], 0.65 [0.18]) was significantly lower than that for the pseudophakia group (mean [SD], 0.77 [0.16]) and the control group (mean [SD], 0.76 [0.19]) (P < .001 for both). The correlation between the ACC and Early Treatment Diabetic Retinopathy Study visual acuity (r = −0.22) and Pelli-Robson contrast sensitivity (r = 0.20) was weaker than that with a reading-related measure of instrumental activities of daily living (r = −0.60) (P < .001 for both). CONCLUSIONS AND RELEVANCE The ACC represents

  7. The Correlation of Age and Postoperative Visual Acuity for Age-Related Cataract

    PubMed Central

    Li, Xiaochun; Cao, Xiaoguang; Hou, Xianru; Bao, Yongzhen

    2016-01-01

    Purpose. Clinically, what is the best time for age-related cataract (ARC) patients to receive surgeries and get the most benefits is important. We explored the relationship between age and presenting postoperative visual acuity (POVA) in patients from rural China. Methods. Three Lifeline Express Hospital Eye-Train missions of Peking University People's Hospital were chosen. At the first day after surgery, 3452 ARC eyes with the presenting POVA ≥ 6/60 were enrolled. The relationship between age and POVA was analyzed statistically. Results. In these three missions, there were more female patients than males; the ratio of females to males was 1.71. The average age of females was older than males. Overall, the percentages of patients with good visual outcomes (≥6/18) were significantly decreased with aging. Different regions had variations, but the trends were the same. There was weak linear correlation between age and POVA. The correlations of females were stronger than males in Yuncheng and Sanmenxia and weaker than males in Zhoukou. Conclusion. The good visual outcomes of presenting POVA were significantly decreased with aging and there were weak linear correlations between age and POVA in rural China. The linear correlation might be influenced by the difference of gender and region. PMID:26881225

  8. Use of optical coherence tomography to evaluate visual acuity and visual field changes in dengue fever.

    PubMed

    Rhee, Taek Kwan; Han, Jung Il

    2014-02-01

    Dengue fever is a viral disease that is transmitted by mosquitoes and affects humans. In rare cases, dengue fever can cause visual impairment, which usually occurs within 1 month after contracting dengue fever and ranges from mild blurring of vision to severe blindness. Visual impairment due to dengue fever can be detected through angiography, retinography, optical coherence tomography (OCT) imaging, electroretinography, event electroencephalography (visually evoked potentials), and visual field analysis. The purpose of this study is to report changes in the eye captured using fluorescein angiography, indocyanine green, and OCT in 3 cases of dengue fever visual impairment associated with consistent visual symptoms and similar retinochoroidopathic changes. The OCT results of the three patients with dengue fever showed thinning of the outer retinal layer and disruption of the inner segment/outer segment (IS/OS) junction. While thinning of the retina outer layer is an irreversible process, disruption of IS/OS junction is reported to be reversible. Follow-up examination of individuals with dengue fever and associated visual impairment should involve the use of OCT to evaluate visual acuity and visual field changes in patients with acute choroidal ischemia.

  9. Visual acuity performance of several observers using the triangle orientation discrimination methodology

    NASA Astrophysics Data System (ADS)

    Mündel, Julia; Geisel, Bärbel; Braesicke, Katrin; Bürsing, Helge

    2016-10-01

    The Triangle Orientation Discrimination (TOD) is one of several methods to characterize electro-optical system performance. It is conducted by presenting an equilateral triangle pointing either up, down, right or left, to an observer who is forced to judge the direction. Based from the probability on the correctness of the answers in dependence of the size of the triangle, the quality of the system can be assessed. In order to gain experience with this method it was applied here to test Fraunhofer IOSBs new equipment for perception experiments. An experiment with four observers, ten contrast levels and six triangle sizes was conducted. Its results were analysed for observer performance versus time, illumination conditions and variations in the TOD-curve. Furthermore, different approaches on analysing the data were compared. The outcome showed the observers performance variation on different days to be statistically insignificant. In addition, the illumination conditions had no statistically significant influence on the result. Interestingly a larger difference was found between the observers. Although they had normal or corrected to normal eyesight, different visual acuity is the only explanation for the differences. This leads to the necessity to check observers of perception experiments more closely. The different approaches to curve fitting also gave variations, which would result in different ranges when applied in camera assessment. Here a standardization seems necessary when the method is applied in analytical models for imaging systems.

  10. Changes in Near Visual Acuity of Over Time in the Astronaut Corps

    NASA Technical Reports Server (NTRS)

    Taiym, Wafa; Wear, Mary L.; Locke, James; Mason, Sara; VanBaalen, Mary

    2014-01-01

    We hypothesized that visual impairment due to intracranial pressure (VIIP) would increase the rate of which presbyopia would occur in the astronaut population, with long durations flyers at an especially high risk. Presbyopia is characterized as the gradual loss of near visual acuity overtime due to a loss in ability to accommodate. It generally develops in the mid-40s and progresses until about age 65. This analysis considered annual vision exams conducted on active NASA astronauts with spaceflight experience currently between the ages of 40 to 60 years of age. Onset of presbyopia was characterized as a shift of at least 20 units on the standard Snellen test from one annual exam to the next. There were 236 short duration and 48 long duration flyers, the majority of whom did experience onset of presbyopia between age 40 and 60. This shift however, did not necessarily come after spaceflight. In comparing the short and long duration flyers the mean age of onset was 47 years old (SD+/-3.7). The mean of onset within the general population is 45 to 47 years old [1, 2]. The mean age of the onset of presbyopia as compared to the general population indicates that space flight does not induce early development of presbyopia.

  11. Designing GUIs for low vision by simulating reduced visual acuity: reduced resolution versus shrinking.

    PubMed

    Sandnes, Frode Eika

    2015-01-01

    The visual uniqueness of information carrying icon and text elements has received little attention in the HCI research literature. The information carrying elements of graphical designs must be visually unique in order to be visually recognizable. This is increasingly important with the diversity of form factors and types of information displays. This paper explores two simple strategies for testing visual designs by simulating low visual acuity, namely by reducing the resolution and by shrinking. Two case studies demonstrate that low vision simulation by shrinking is more effective than reducing the resolution. Moreover, the case studies show how the low vision simulation can help identify design aspects that need attention. Design shrinking is not a substitute for user testing on actual user groups, but meant as a tool for early screening of designs and an aid for designers to help understand the effects of their design. The method can also be used as a tool for communicating design problems and justifying design decisions to stakeholders of a project through presentations and reports.

  12. Ultrananocrystalline diamond-CMOS device integration route for high acuity retinal prostheses.

    PubMed

    Ahnood, A; Escudie, M C; Cicione, R; Abeyrathne, C D; Ganesan, K; Fox, K E; Garrett, D J; Stacey, A; Apollo, N V; Lichter, S G; Thomas, C D L; Tran, N; Meffin, H; Prawer, S

    2015-01-01

    High density electrodes are a new frontier for biomedical implants. Increasing the density and the number of electrodes used for the stimulation of retinal ganglion cells is one possible strategy for enhancing the quality of vision experienced by patients using retinal prostheses. The present work presents an integration strategy for a diamond based, high density, stimulating electrode array with a purpose built application specific integrated circuit (ASIC). The strategy is centered on flip-chip bonding of indium bumps to create high count and density vertical interconnects between the stimulator ASIC and an array of diamond neural stimulating electrodes. The use of polydimethylsiloxane (PDMS) housing prevents cross-contamination of the biocompatible diamond electrode with non-biocompatible materials, such as indium, used in the microfabrication process. Micro-imprint lithography allowed edge-to-edge micro-scale pattering of the indium bumps on non-coplanar substrates that have a form factor that can conform to body organs and thus are ideally suited for biomedical applications. Furthermore, micro-imprint lithography ensures the compatibility of lithography with the silicon ASIC and aluminum contact pads. Although this work focuses on 256 stimulating diamond electrode arrays with a pitch of 150 μm, the use of indium bump bonding technology and vertical interconnects facilitates implants with tens of thousands electrodes with a pitch as low as 10 μm, thus ensuring validity of the strategy for future high acuity retinal prostheses, and bionic implants in general.

  13. Improvement of visual acuity in diabetic and nondiabetic patients after Nd:YAG laser capsulotomy

    PubMed Central

    Awan, Muhammed Tayyab; Khan, Muhammed Anwar; Al-Khairy, Saba; Malik, Samina

    2013-01-01

    Purpose The aim of the study reported here was to compare the improvement of visual acuity (VA) of diabetic and nondiabetic patients after neodymium-doped yttrium-aluminum-garnet (Nd:YAG) laser capsulotomy. Methods In this prospective cohort study, 50 age- and sex-matched patients, comprising 25 nondiabetics and 25 diabetics (referred to as Group A and B, respectively), with posterior chamber poly(methyl methacrylate) non-foldable intraocular lens implants attending our clinic at Karachi for capsulotomy had pre- and postoperative measures of VA, posterior pole visibility, and grading of posterior capsular opacity as seen on slit-lamp examination. VA was recorded before and after performing standard capsulotomy. Results The postoperative (mean) VA in nondiabetics was 0.25, 0.23, and 0.21 logMAR as compared with 0.25, 0.25, and 0.24 logMAR in diabetics at 1 week, 1 month, and 6 months, respectively. P-values of 0.47, 0.47, and 0.24, respectively, were determined, which were not significant. Preoperative VA improvement was recorded in 92% of diabetics in Group B and 96% of nondiabetics in Group A. Two (8%) diabetic patients developed glaucoma and did not participate in the study further. Conclusion Remarkable improvement in VA was achieved in both Group A and B, but the Group A nondiabetics showed more improvement in best-corrected VA after Nd:YAG laser capsulotomy. PMID:24143068

  14. Origins of superior dynamic visual acuity in baseball players: superior eye movements or superior image processing.

    PubMed

    Uchida, Yusuke; Kudoh, Daisuke; Murakami, Akira; Honda, Masaaki; Kitazawa, Shigeru

    2012-01-01

    Dynamic visual acuity (DVA) is defined as the ability to discriminate the fine parts of a moving object. DVA is generally better in athletes than in non-athletes, and the better DVA of athletes has been attributed to a better ability to track moving objects. In the present study, we hypothesized that the better DVA of athletes is partly derived from better perception of moving images on the retina through some kind of perceptual learning. To test this hypothesis, we quantitatively measured DVA in baseball players and non-athletes using moving Landolt rings in two conditions. In the first experiment, the participants were allowed to move their eyes (free-eye-movement conditions), whereas in the second they were required to fixate on a fixation target (fixation conditions). The athletes displayed significantly better DVA than the non-athletes in the free-eye-movement conditions. However, there was no significant difference between the groups in the fixation conditions. These results suggest that the better DVA of athletes is primarily due to an improved ability to track moving targets with their eyes, rather than to improved perception of moving images on the retina.

  15. Development of microcomputer-based mental acuity tests for repeated-measures studies

    NASA Technical Reports Server (NTRS)

    Kennedy, R. S.; Wilkes, R. L.; Baltzley, D. R.; Fowlkes, J. E.

    1990-01-01

    The purpose of this report is to detail the development of the Automated Performance Test System (APTS), a computer battery of mental acuity tests that can be used to assess human performance in the presence of toxic elements and environmental stressors. There were four objectives in the development of APTS. First, the technical requirements for developing APTS followed the tenets of the classical theory of mental tests which requires that tests meet set criteria like stability and reliability (the lack of which constitutes insensitivity). To be employed in the study of the exotic conditions of protracted space flight, a battery with multiple parallel forms is required. The second criteria was for the battery to have factorial multidimensionality and the third was for the battery to be sensitive to factors known to compromise performance. A fourth objective was for the tests to converge on the abilities entailed in mission specialist tasks. A series of studies is reported in which candidate APTS tests were subjected to an examination of their psychometric properties for repeated-measures testing. From this work, tests were selected that possessed the requisite metric properties of stability, reliability, and factor richness. In addition, studies are reported which demonstrate the predictive validity of the tests to holistic measures of intelligence.

  16. Aircrew visual acuity viewing with different night vision goggle eyepiece diopter settings

    NASA Astrophysics Data System (ADS)

    Angel, Share-Dawn P.; Baldwin, J. Bruce

    2004-09-01

    The AN/AVS-9 night vision goggle (NVG) has an eyepiece lens that can be adjusted from +2 to -6 diopters (D). We have shown previously1,2,3 that on average NVG users tend to select about -1D, with a range of +0.5D to -4D3. This study was designed to evaluate NVG visual acuity (NVG VA) and subjective ratings for a range of diopter settings including user-selected and three fixed settings of -0.25D, -1D and -2D. Twenty-one experienced USAF Special Operations aircrew members, including 15 pilots, served as subjects. The median user-selected setting was -1.25D and ranged from +0.5D to -3.5D. Only 2 of the 21 subjects had user-selected NVG VA significantly better than a fixed setting of -1D. Of those two, one was not wearing prescribed glasses and the other was 49 years old, presbyopic, and could not focus through the -1D lenses. Subjective ratings and NVG VA indicated that most people could fly with a fixed setting of -1D for each eye, although two individuals needed different diopter settings for the right and left eyes. The new Panoramic NVG (PNVG) has a fixed eyepiece focus of -1D. Results suggest the PNVG should have a limited set of accessory lenses available.

  17. Change in visual acuity is highly correlated with change in six image quality metrics independent of wavefront error and/or pupil diameter

    PubMed Central

    Ravikumar, Ayeswarya; Sarver, Edwin J.; Applegate, Raymond A.

    2012-01-01

    It is well known that the wavefront error (WFE) of the eye varies from individual to individual with pupil diameter (PD) and age. Numerous studies have been proposed evaluating the relationship between visual acuity and WFE, but all these studies were performed with either a fixed or natural PD. It is still not clear if metrics of image quality correlate well with visual acuity independent of PD. Here we investigate the correlation between the change in visual acuity and the change in 30 image quality metrics for a range of optical quality typically established in normal eyes that varies both with age and PD. Visual acuity was recorded for 4 normal subjects using simulated blurred logMAR acuity charts generated from the point spread functions of different scaled WFEs for 6 different PDs (2–7 mm in 1 mm steps). Six image quality metrics (log neural sharpness, log visual Strehl [spatial domain], log visual Strehl [MTF method], log pupil fraction [tessellated], log pupil fraction [concentric area], and log root mean square of WFE slope) accounted for over 80% of variance in change in acuity across all WFEs and all PDs. Multiple regression analysis did not significantly increase the R2. Simple metrics derived from WFE could potentially act as an objective surrogate to visual acuity without the need for complex models. PMID:22984224

  18. Unchanged content of oxidative enzymes in fast-twitch muscle fibers and V˙O2 kinetics after intensified training in trained cyclists.

    PubMed

    Christensen, Peter M; Gunnarsson, Thomas P; Thomassen, Martin; Wilkerson, Daryl P; Nielsen, Jens Jung; Bangsbo, Jens

    2015-07-01

    The present study examined if high intensity training (HIT) could increase the expression of oxidative enzymes in fast-twitch muscle fibers causing a faster oxygen uptake (V˙O2) response during intense (INT), but not moderate (MOD), exercise and reduce the V˙O2 slow component and muscle metabolic perturbation during INT. Pulmonary V˙O2 kinetics was determined in eight trained male cyclists (V˙O2-max: 59 ± 4 (means ± SD) mL min(-1) kg(-1)) during MOD (205 ± 12 W ~65% V˙O2-max) and INT (286 ± 17 W ~85% V˙O2-max) exercise before and after a 7-week HIT period (30-sec sprints and 4-min intervals) with a 50% reduction in volume. Both before and after HIT the content in fast-twitch fibers of CS (P < 0.05) and COX-4 (P < 0.01) was lower, whereas PFK was higher (P < 0.001) than in slow-twitch fibers. Content of CS, COX-4, and PFK in homogenate and fast-twitch fibers was unchanged with HIT. Maximal activity (μmol g DW(-1) min(-1)) of CS (56 ± 8 post-HIT vs. 59 ± 10 pre-HIT), HAD (27 ± 6 vs. 29 ± 3) and PFK (340 ± 69 vs. 318 ± 105) and the capillary to fiber ratio (2.30 ± 0.16 vs. 2.38 ± 0.20) was unaltered following HIT. V˙O2 kinetics was unchanged with HIT and the speed of the primary response did not differ between MOD and INT. Muscle creatine phosphate was lower (42 ± 15 vs. 66 ± 17 mmol kg DW(-1)) and muscle lactate was higher (40 ± 18 vs. 14 ± 5 mmol kg DW(-1)) at 6 min of INT (P < 0.05) after compared to before HIT. A period of intensified training with a volume reduction did not increase the content of oxidative enzymes in fast-twitch fibers, and did not change V˙O2 kinetics.

  19. Stroboscopic Goggles as a Countermeasure for Dynamic Visual Acuity and Landing Sickness in Crewmembers Returning from Long-Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Rosenberg, M. J. F.; Kreutzberg, G. A.; Peters, B. T.; Reschke, M. F.

    2017-01-01

    Long-term exposure to microgravity causes sensorimotor adaptations that result in functional deficits upon returning to a gravitational environment. At landing, the vestibular system and the central nervous system, responsible for coordinating head and eye movements via the vestibulo-occular reflex (VOR), are adapted to microgravity and must re-adapt to the Earth's gravitational environment. This re-adaptation causes decrements in gaze control and dynamic visual acuity, with astronauts reporting oscillopsia and blurred vision. These effects are caused by retinal slip, or the inability to keep an image focused on their retina, which is thought to drive motion sickness symptoms experienced upon landing. Retinal slip can be estimated by dynamic visual acuity (DVA); visual acuity while in motion. Peters et al. (2011) find that DVA is worsened in astronauts by an average of 0.75 eye-chart lines one day after landing. Previously, the use of stroboscopic goggles has shown to be effective in minimizing motion sickness symptoms due to retinal slip (Reschke et al. 2007). In this study, we simulated the decrement in DVA caused by sensorimotor re-adaptation by using minifying lenses and then testing the efficacy of stroboscopic goggles in preventing retinal slip and improving DVA. Dynamic visual acuity is assessed using an oscillating chair developed in the Neuroscience Laboratory at JSC. This chair is motor-driven and oscillates vertically at 2 Hz with a vertical displacement of +/- 2 cm to simulate the vertical translations that occur while walking. As the subject is being oscillated, they are asked to discern the direction of Landolt-C optotypes of varying sizes and record their direction using a gamepad. The visual acuity thresholds are determined using an algorithm that alters the size of the optotype based on the previous responses of the subject using a forced-choice best parameter estimation that is able to rapidly converge on the threshold value. Visual acuity

  20. Comparability of ophthalmic diagnoses by clinical and Reading Center examiners in the Visual Acuity Impairment Survey Pilot Study.

    PubMed

    Sperduto, R D; Hiller, R; Podgor, M J; Palmberg, P; Ferris, F L; Wentworth, D

    1986-12-01

    Technologic advances in ophthalmic equipment offer the possibility of replacing direct clinical examinations with Reading Center evaluations of data recorded in epidemiologic studies. Clinical and Reading Center examiners made independent ophthalmic diagnoses of 133 right and 132 left eyes of 138 adults in the Visual Acuity Impairment Survey Pilot Study, carried out in three US cities, Boston, Detroit, and Minneapolis, in August 1981-December 1982. The Reading Center diagnosed eye conditions using only photographic and visual field data collected at the time of the clinical examination. In the comparisons of clinical and Reading Center evaluations reported here, only eyes judged by the examiners to have pathology severe enough to reduce visual acuity to 6/9 or worse were classified as having pathology. (No visual acuity criterion was required for the diagnosis of glaucoma or diabetic retinopathy.) There was agreement in diagnostic assessments between clinical and Reading Center examiners in about 80% of eyes. The kappa statistic, which adjusts for chance agreement, was in the fair to good range: 0.60 for 133 right eyes and 0.62 for 132 left eyes. When the Reading Center examiners were provided with additional information on medical history, refractive error and best corrected visual acuity, the agreement between clinical and Reading Center assessments among the subset of eyes with 6/9 or worse vision again was in the fair to good range, with kappas of 0.61 for 45 right eyes and 0.68 for 48 left eyes. Inter-observer agreement between Reading Center examiners in diagnosing pathology was in the good to excellent range. Use of Reading Centers in future epidemiologic studies should be considered, but elimination of the clinical examinations is not recommended until modifications in the protocol described here have been made and shown to improve levels of agreement between clinical and Reading Center examiners.

  1. Is 20/20 vision good enough? Visual acuity differences within the normal range predict contour element detection and integration.

    PubMed

    Keane, Brian P; Kastner, Sabine; Paterno, Danielle; Silverstein, Steven M

    2015-02-01

    Contour integration (CI) combines appropriately aligned and oriented elements into continuous boundaries. Collinear facilitation (CF) occurs when a low-contrast oriented element becomes more visible when flanked by collinear high-contrast elements. Both processes rely at least partly on long-range horizontal connections in early visual cortex, and thus both have been extensively studied to understand visual cortical functioning in aging, development, and clinical disorders. Here, we ask: Can acuity differences within the normal range predict CI or CF? To consider this question, we measured binocular visual acuity and compared subjects with 20/20 vision to those with better-than-20/20 vision (SharpPerceivers) on two tasks. In the CI task, subjects located an integrated shape embedded in varying amounts of noise; in the CF task, subjects detected a low-contrast element flanked by collinear or orthogonal high-contrast elements. In each case, displays were scaled in size to modulate element visibility and spatial frequency (4-12 cycles/deg). SharpPerceivers could integrate contours under noisier conditions than the 20/20 group (p = .0002), especially for high spatial frequency displays. Moreover, although the two groups exhibited similar collinear facilitation, SharpPerceivers could detect the central target with lower contrast at high spatial frequencies (p <. 05). These results suggest that small acuity differences within the normal range--corresponding to about a one line difference on a vision chart--strongly predict element detection and integration. Furthermore, simply ensuring that subjects have normal or corrected-to-normal vision is not sufficient when comparing groups on contour tasks; visual acuity confounds also need to be ruled out.

  2. Health benefits in 2007: premium increases fall to an eight-year low, while offer rates and enrollment remain stable.

    PubMed

    Claxton, Gary; Gabel, Jon; DiJulio, Bianca; Pickreign, Jeremy; Whitmore, Heidi; Finder, Benjamin; Jacobs, Paul; Hawkins, Samantha

    2007-01-01

    This paper reports findings from a survey of 1,997 public and private employers with three or more workers, conducted during the first five months of 2007. Premiums increased 6.1 percent from spring 2006 to spring 2007--the lowest rate of increase since 1999. Enrollment in different types of health plans did not change significantly, and high-deductible health plans with a savings option did not experience major growth in enrollment. Despite the comparatively modest increase in premiums during a period of strong economic growth, the percentage of workers obtaining coverage from their employer remained statistically unchanged.

  3. Chronic alcoholism in rats induces a compensatory response, preserving brain thiamine diphosphate, but the brain 2-oxo acid dehydrogenases are inactivated despite unchanged coenzyme levels.

    PubMed

    Parkhomenko, Yulia M; Kudryavtsev, Pavel A; Pylypchuk, Svetlana Yu; Chekhivska, Lilia I; Stepanenko, Svetlana P; Sergiichuk, Andrej A; Bunik, Victoria I

    2011-06-01

    Thiamine-dependent changes in alcoholic brain were studied using a rat model. Brain thiamine and its mono- and diphosphates were not reduced after 20 weeks of alcohol exposure. However, alcoholism increased both synaptosomal thiamine uptake and thiamine diphosphate synthesis in brain, pointing to mechanisms preserving thiamine diphosphate in the alcoholic brain. In spite of the unchanged level of the coenzyme thiamine diphosphate, activities of the mitochondrial 2-oxoglutarate and pyruvate dehydrogenase complexes decreased in alcoholic brain. The inactivation of pyruvate dehydrogenase complex was caused by its increased phosphorylation. The inactivation of 2-oxoglutarate dehydrogenase complex (OGDHC) correlated with a decrease in free thiols resulting from an elevation of reactive oxygen species. Abstinence from alcohol following exposure to alcohol reactivated OGDHC along with restoration of the free thiol content. However, restoration of enzyme activity occurred before normalization of reactive oxygen species levels. Hence, the redox status of cellular thiols mediates the action of oxidative stress on OGDHC in alcoholic brain. As a result, upon chronic alcohol consumption, physiological mechanisms to counteract the thiamine deficiency and silence pyruvate dehydrogenase are activated in rat brain, whereas OGDHC is inactivated due to impaired antioxidant ability.

  4. Improvement of tactile roughness discrimination acuity correlates with perception of improved hand function in patients after hand surgery

    PubMed Central

    Fujimoto, Shuhei; Kon, Noriko

    2016-01-01

    [Purpose] The purpose of this study was to elucidate how well patients’ perceptions related to the improvements in their hand function during hospitalization. [Subjects] Sixteen patients who were hospitalized after hand surgery. [Methods] Using the Japanese Society for Surgery of the Hand edition of the Quick-Disabilities of the Arm, Shoulder, and Hand questionnaire; tactile roughness discrimination acuity, motor imagery, motor function, sensory function, and pain of the upper limb were assessed at admission and discharge. Spearman’s rank-order correlation coefficients were calculated using the differences in all assessment items at admission and discharge. A multiple regression analysis (stepwise method) was performed to investigate factors that correlated with improvements in Quick-Disabilities of the Arm, Shoulder, and Hand scores. [Results] The improvement of tactile roughness discrimination acuity was significantly associated with patient perception of improved hand function. [Conclusion] The results suggest that an improvement in tactile roughness discrimination acuity was most strongly correlated with patient perception of improved hand function. PMID:27190473

  5. The role of ANS acuity and numeracy for the calibration and the coherence of subjective probability judgments

    PubMed Central

    Winman, Anders; Juslin, Peter; Lindskog, Marcus; Nilsson, Håkan; Kerimi, Neda

    2014-01-01

    The purpose of the study was to investigate how numeracy and acuity of the approximate number system (ANS) relate to the calibration and coherence of probability judgments. Based on the literature on number cognition, a first hypothesis was that those with lower numeracy would maintain a less linear use of the probability scale, contributing to overconfidence and nonlinear calibration curves. A second hypothesis was that also poorer acuity of the ANS would be associated with overconfidence and non-linearity. A third hypothesis, in line with dual-systems theory (e.g., Kahneman and Frederick, 2002) was that people higher in numeracy should have better access to the normative probability rules, allowing them to decrease the rate of conjunction fallacies. Data from 213 participants sampled from the Swedish population showed that: (i) in line with the first hypothesis, overconfidence and the linearity of the calibration curves were related to numeracy, where people higher in numeracy were well calibrated with zero overconfidence. (ii) ANS was not associated with overconfidence and non-linearity, disconfirming the second hypothesis. (iii) The rate of conjunction fallacies was slightly, but to a statistically significant degree decreased by numeracy, but still high at all numeracy levels. An unexpected finding was that participants with better ANS acuity gave more realistic estimates of their performance relative to others. PMID:25140163

  6. Quantitative Analysis of the Effects of a Bangerter Filter on Gross Stereopsis in Experimental Models of Reduced Visual Acuity.

    PubMed

    Miyata, Manabu; Nakahara, Ryuichi; Hamasaki, Ichiro; Hasebe, Satoshi; Furuse, Takashi; Ohtsuki, Hiroshi

    2016-10-01

    Although a 0.3 Bangerter filter, which reduces visual acuity, is frequently used for treating moderate amblyopia, the effects on gross stereopsis are not well known. This study quantitatively evaluated whether gross stereopsis is degraded by a Bangerter filter. Seven healthy subjects (median age: 29 years) participated in this psychophysical study. Targets with crossed disparities of 1°, 2°, 3°, 4°, and 5° were randomly presented on a three-dimensional television display. The subjects indicated the point at which the targets popped out from the television screen (matching method). The distance from the screen to the point was defined as the degree of stereopsis. This experiment was performed with and without a 0.3 Bangerter filter. The corrected monocular visual acuities were decreased to about 20/63 by the filter in all subjects. No significant difference was observed for any of the disparities (1°-5°), between the degree of stereopsis visualized with and without filters for either the dominant or the non-dominant eye. The degree of stereopsis was not degraded by the reduced visual acuity induced by the use of 0.3 Bangerter filters. In this regard, the use of 0.3 Bangerter filters may be considered safer than occlusion eye patches for the patients with normal binocular vision.

  7. 43 CFR 4730.2 - Disposal of remains.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... HORSES AND BURROS Destruction of Wild Horses or Burros and Disposal of Remains § 4730.2 Disposal of remains. Remains of wild horses or burros that die after capture shall be disposed of in accordance...

  8. 43 CFR 4730.2 - Disposal of remains.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... HORSES AND BURROS Destruction of Wild Horses or Burros and Disposal of Remains § 4730.2 Disposal of remains. Remains of wild horses or burros that die after capture shall be disposed of in accordance...

  9. 43 CFR 4730.2 - Disposal of remains.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... HORSES AND BURROS Destruction of Wild Horses or Burros and Disposal of Remains § 4730.2 Disposal of remains. Remains of wild horses or burros that die after capture shall be disposed of in accordance...

  10. 43 CFR 4730.2 - Disposal of remains.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... HORSES AND BURROS Destruction of Wild Horses or Burros and Disposal of Remains § 4730.2 Disposal of remains. Remains of wild horses or burros that die after capture shall be disposed of in accordance...

  11. Metformin Impairs Spatial Memory and Visual Acuity in Old Male Mice

    PubMed Central

    Thangthaeng, Nopporn; Rutledge, Margaret; Wong, Jessica M.; Vann, Philip H.; Forster, Michael J.; Sumien, Nathalie

    2017-01-01

    Metformin is an oral anti-diabetic used as first-line therapy for type 2 diabetes. Because benefits of metformin extend beyond diabetes to other age-related pathology, and because its effect on gene expression profiles resembles that of caloric restriction, metformin has a potential as an anti-aging intervention and may soon be assessed as an intervention to extend healthspan. However, beneficial actions of metformin in the central nervous system have not been clearly established. The current study examined the effect of chronic oral metformin treatment on motor and cognitive function when initiated in young, middle-aged, or old male mice. C57BL/6 mice aged 4, 11, or 22 months were randomly assigned to either a metformin group (2 mg/ml in drinking water) or a control group. The mice were monitored weekly for body weight, as well as food and water intake and a battery of behavioral tests for motor, cognitive and visual function was initiated after the first month of treatment. Liver, hippocampus and cortex were collected at the end of the study to assess redox homeostasis. Overall, metformin supplementation in male mice failed to affect blood glucose, body weights and redox homeostasis at any age. It also had no beneficial effect on age-related declines in psychomotor, cognitive or sensory functions. However, metformin treatment had a deleterious effect on spatial memory and visual acuity, and reduced SOD activity in brain regions. These data confirm that metformin treatment may be associated with deleterious effect resulting from the action of metformin on the central nervous system. PMID:28203479

  12. Insurance Status is Associated with Acuity of Presentation and Outcomes for Thoracic Aortic Operations

    PubMed Central

    Andersen, Nicholas D.; Brennan, J. Matthew; Zhao, Yue; Williams, Judson B.; Williams, Matthew L.; Smith, Peter K.; Scarborough, John E.; Hughes, G. Chad

    2014-01-01

    Background Non-elective procedure status is the greatest risk factor for postoperative morbidity and mortality in patients undergoing thoracic aortic operations. We hypothesized that uninsured patients were more likely to require non-elective thoracic aortic operation due to decreased access to preventative care and elective surgical services. Methods and Results An observational study of the Society of Thoracic Surgeons Database identified 51,282 patients who underwent thoracic aortic surgery between 2007–2011 at 940 North American centers. Patients were stratified by insurance status (private insurance, Medicare, Medicaid, other insurance, or uninsured) as well as age < 65 years or age ≥ 65 years to account for differences in Medicare eligibility. The need for non-elective thoracic aortic operation was highest for uninsured patients (71.7%) and lowest for privately insured patients (36.6%). The adjusted risks of non-elective operation were increased for uninsured patients (adjusted risk ratio [ARR], 1.77; 95% confidence interval [CI], 1.70–1.83 for age < 65 years; ARR, 1.46; 95% CI, 1.29–1.62 for age ≥ 65 years) as well as Medicaid patients age < 65 years (ARR, 1.18; 95% CI, 1.10–1.26) when compared to patients with private insurance. The adjusted odds of major morbidity and/or mortality were further increased for all patients age < 65 years without private insurance (ARRs between 1.13 and 1.27). Conclusions Insurance status was associated with acuity of presentation and major morbidity and mortality for thoracic aortic operations. Efforts to reduce insurance-based disparities in the care of patients with thoracic aortic disease appear warranted and may reduce the incidence of aortic emergencies and improve outcomes after thoracic aortic surgery. PMID:24714600

  13. A novel computer software for the evaluation of dynamic visual acuity

    PubMed Central

    Quevedo, Lluïsa; Aznar-Casanova, José Antonio; Merindano-Encina, Dolores; Cardona, Genís; Solé-Fortó, Joan

    2012-01-01

    Purpose Dynamic visual acuity (DVA) is defined as the ability to discriminate fine details in a moving target. Albeit a growing interest in DVA, there is a lack of standardized, validated instrumentation and procedures for the assessment of this visual function parameter. The aim of the present study was to analyze qualitative construct validity and test–retest reliability of a novel, computer-assisted instrument (DinVA 3.0) for the measurement of DVA. Methods Two different experiments are presented, involving the participation of 33 subjects. The first experiment aimed at testing qualitative construct validity of the DinVA 3.0 by comparing the outcome of a series of trials consisting in different speeds, contrasts and trajectories of the target stimuli with those reported in the literature. The second experiment assessed test–retest reliability by repeating a series of trials at three different time intervals, at maximum target stimuli contrast and either high or low speed configurations. Results The results of the first experiment gave support to the qualitative construct validity of DinVA 3.0, as the DVA scores were found to be modulated by the speed of the moving target (high speeds yielded lower DVA), contrast (high contrast resulted in better DVA) and trajectory (DVA was better at horizontal rather than oblique trajectories). Test–retest reliability was found to be good, with a small insignificant trend towards improvement with learning. Conclusion The DinVA 3.0 proved to be a valid and reliable instrument for the assessment of DVA and may be considered a promising tool for both clinicians and researchers.

  14. Testing vision testing: quantifying the effect of movement on visual acuity measurement

    PubMed Central

    Tidbury, L P; O'Connor, A R

    2015-01-01

    Purpose Assessment of visual acuity (VA) has been shown to vary between tests, which may be attributable in part to test inaccuracies, such as a change in the distance between the chart and subject. Therefore, the study aim was to quantify changes in chart/patient separation during near and distance VA testing, and to analyse the relationship between VA and movement observed. Methods Volunteer orthoptists and subjects were filmed during near and distance VA testing, with the amount of movement determined from the recording. Controlling for movement using chin rests and chart stands, VA was retested. Actual changes in VA due to a change in subject or chart movement were compared with theoretical predictions. Results Fifty-one subjects (18–73 years) were assessed. Median (interquartile) movements of 0.06 m (0.07) towards and 0.11 m (0.08) away from the chart were measured (maximum 0.17 m towards and 0.24 m away). Significant differences in VA score were measured when movement was restricted, at near and distance (P<0.05). VA score change agreed with predicted values in 67% of the cases, however, reduced test distance during near vision testing resulted in a degradation of VA, opposite to the improvement expected. Conclusion There were significant variations in subject/chart separation during testing, which could have affected VA values. While this movement is associated with a change in VA, additional factors to movement appear to influence the score achieved during near testing. Procedures to minimise variation, by eliminating movement of test chart or subject, will improve VA test accuracy. PMID:25341437

  15. Intake of up to 3 Eggs/Day Increases HDL Cholesterol and Plasma Choline While Plasma Trimethylamine-N-oxide is Unchanged in a Healthy Population.

    PubMed

    DiMarco, Diana M; Missimer, Amanda; Murillo, Ana Gabriela; Lemos, Bruno S; Malysheva, Olga V; Caudill, Marie A; Blesso, Christopher N; Fernandez, Maria Luz

    2017-03-01

    Eggs are a source of cholesterol and choline and may impact plasma lipids and trimethylamine-N-oxide (TMAO) concentrations, which are biomarkers for cardiovascular disease (CVD) risk. Therefore, the effects of increasing egg intake (0, 1, 2, and 3 eggs/day) on these and other CVD risk biomarkers were evaluated in a young, healthy population. Thirty-eight subjects [19 men/19 women, 24.1 ± 2.2 years, body mass index (BMI) 24.3 ± 2.5 kg/m(2)] participated in this 14-week crossover intervention. Participants underwent a 2-week washout with no egg consumption, followed by intake of 1, 2, and 3 eggs/day for 4 weeks each. Anthropometric data, blood pressure (BP), dietary records, and plasma biomarkers (lipids, glucose, choline, and TMAO) were measured during each intervention phase. BMI, waist circumference, systolic BP, plasma glucose, and plasma triacylglycerol did not change throughout the intervention. Diastolic BP decreased with egg intake (P < 0.05). Compared to 0 eggs/day, intake of 1 egg/day increased HDL cholesterol (HDL-c) (P < 0.05), and decreased LDL cholesterol (LDL-c) (P < 0.05) and the LDL-c/HDL-c ratio (P < 0.01). With intake of 2-3 eggs/day, these changes were maintained. Plasma choline increased dose-dependently with egg intake (P < 0.0001) while fasting plasma TMAO was unchanged. These results indicate that in a healthy population, consuming up to 3 eggs/day results in an overall beneficial effect on biomarkers associated with CVD risk, as documented by increased HDL-c, a reduced LDL-c/HDL-c ratio, and increased plasma choline in combination with no change in plasma LDL-c or TMAO concentrations.

  16. In vivo evaluation of bioactive PMMA-based bone cement with unchanged mechanical properties in a load-bearing model on rabbits.

    PubMed

    Fottner, Andreas; Nies, Berthold; Kitanovic, Denis; Steinbrück, Arnd; Hausdorf, Jörg; Mayer-Wagner, Susanne; Pohl, Ulrich; Jansson, Volkmar

    2015-07-01

    Polymethylmethacrylate-based bone cements are widely used for fixation of joint replacements. To improve the long-term outcome, bioactive bone cements are aspired to advance the bone-cement interface. This study evaluated the in vivo properties of a new polymethylmethacrylate-based bioactive bone cement with addition of amphiphilic phosphorylated 2-hydroxyethylmethacrylate. Previous in vitro studies confirmed bioactive properties in cell culture, as well as unchanged mechanical properties are tests according to ISO 5833:2002.Three different variations of the cement (polymethylmethacrylate + phosphorylated 2-hydroxyethylmethacrylate, polymethylmethacrylate + phosphorylated 2-hydroxyethylmethacrylate + CaCl2 and polymethylmethacrylate + phosphorylated 2-hydroxyethylmethacrylate + CaCl2 + Na2CO3) were compared to conventional polymethylmethacrylate cement. To evaluate the properties under load-bearing conditions, a spacer prosthesis was implanted into the femoral diaphysis of 24 rabbits. Additionally, a cement plug was installed into the proximal tibia. After three months, polished sections with Giemsa surface staining were prepared. The bioactivity was determined using the bone affinity index.The sections showed a good osseointegration of the bioactive bone cement without cement cracks under load-bearing conditions. Regarding the bone affinity index, the bioactive bone cement revealed a significantly higher value in the proximal tibia (25.9-37.7%) and around the spacer prosthesis (36.8-58.9%) compared to the conventional polymethylmethacrylate cement (12.8-17.0%).The results confirm the in vivo bioactivity of this bone cement. The absence of cement cracks indicates a sufficient mechanical stability to fix prostheses with this bioactive cement, but for a final assessment long-term tests are necessary.

  17. Associations among Visual Acuity and Vision- and Health-Related Quality of Life among Patients in the Multicenter Uveitis Steroid Treatment Trial

    PubMed Central

    Drye, Lea T.; Kempen, John H.; Dunn, James P.; Holland, Gary N.; Latkany, Paul; Rao, Narsing A.; Sen, H. Nida; Sugar, Elizabeth A.; Thorne, Jennifer E.; Wang, Robert C.; Holbrook, Janet T.

    2012-01-01

    Purpose. To evaluate the associations between visual acuity and self-reported visual function; visual acuity and health-related quality of life (QoL) metrics; a summary measure of self-reported visual function and health-related QoL; and individual domains of self-reported visual function and health-related QoL in patients with uveitis. Methods. Best-corrected visual acuity, vision-related functioning as assessed by the NEI VFQ-25, and health-related QoL as assessed by the SF-36 and EuroQoL EQ-5D questionnaires were obtained at enrollment in a clinical trial of uveitis treatments. Multivariate regression and Spearman correlations were used to evaluate associations between visual acuity, vision-related function, and health-related QoL. Results. Among the 255 patients, median visual acuity in the better-seeing eyes was 20/25, the vision-related function score indicated impairment (median, 60), and health-related QoL scores were within the normal population range. Better visual acuity was predictive of higher visual function scores (P ≤ 0.001), a higher SF-36 physical component score, and a higher EQ-5D health utility score (P < 0.001). The vision-specific function score was predictive of all general health-related QoL (P < 0.001). The correlations between visual function score and general quality of life measures were moderate (ρ = 0.29–0.52). Conclusions. The vision-related function score correlated positively with visual acuity and moderately positively with general QoL measures. Cost–utility analyses relying on changes in generic healthy utility measures will be more likely to detect changes when there are clinically meaningful changes in vision-related function, rather than when there are only changes in visual acuity. (ClinicalTrials.gov number, NCT00132691.) PMID:22247489

  18. A phytochemical-rich diet may explain the absence of age-related decline in visual acuity of Amazonian hunter-gatherers in Ecuador.

    PubMed

    London, Douglas S; Beezhold, Bonnie

    2015-02-01

    Myopia is absent in undisturbed hunter-gatherers but ubiquitous in modern populations. The link between dietary phytochemicals and eye health is well established, although transition away from a wild diet has reduced phytochemical variety. We hypothesized that when larger quantities and greater variety of wild, seasonal phytochemicals are consumed in a food system, there will be a reduced prevalence of degenerative-based eye disease as measured by visual acuity. We compared food systems and visual acuity across isolated Amazonian Kawymeno Waorani hunter-gatherers and neighboring Kichwa subsistence agrarians, using dietary surveys, dietary pattern observation, and Snellen Illiterate E visual acuity examinations. Hunter-gatherers consumed more food species (130 vs. 63) and more wild plants (80 vs. 4) including 76 wild fruits, thereby obtaining larger variety and quantity of phytochemicals than agrarians. Visual acuity was inversely related to age only in agrarians (r = -.846, P < .001). As hypothesized, when stratified by age (<40 and ≥ 40 years), Mann-Whitney U tests revealed that hunter-gatherers maintained high visual acuity throughout life, whereas agrarian visual acuity declined (P values < .001); visual acuity of younger participants was high across the board, however, did not differ between groups (P > .05). This unusual absence of juvenile-onset vision problems may be related to local, organic, whole food diets of subsistence food systems isolated from modern food production. Our results suggest that intake of a wider variety of plant foods supplying necessary phytochemicals for eye health may help maintain visual acuity and prevent degenerative eye conditions as humans age.

  19. Sporadic Visual Acuity Loss in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT)

    PubMed Central

    Kim, Benjamin J.; Ying, Gui-Shuang; Huang, Jiayan; Levy, Nicole E.; Maguire, Maureen G.

    2014-01-01

    Purpose To evaluate transient, large visual acuity (VA) decreases, termed sporadic vision loss, during anti-vascular endothelial growth factor treatment for neovascular age-related macular degeneration (AMD). Design Cohort within a randomized clinical trial. Methods Setting Comparison of AMD Treatments Trials (CATT). Study Population 1185 CATT patients. Main Outcome Measures incidence of sporadic vision loss and odds ratio (OR) for association with patient and ocular factors. Sporadic vision loss was a decline of ≥ 15 letters from the previous visit, followed by a return at the next visit to no more than 5 letters worse than the visit before the VA loss. Results There were 143 sporadic vision loss events in 122/1185 (10.3%) patients. Mean VA at two years for those with and without sporadic vision loss was 58.5 (~20/63) and 68.4 (~20/40) letters, respectively (P < 0.001). Among patients treated pro re nata, no injection was given for 27.6% (27/98) of sporadic vision loss events. Multivariate analysis demonstrated that baseline predictors for sporadic vision loss included worse baseline VA (OR 2.92, 95%CI:1.65–5.17 for ≤ 20/200 compared with ≥ 20/40), scar (OR 2.21, 95%CI:1.22–4.01), intraretinal foveal fluid on optical coherence tomography (OR 1.80, 95%CI:1.11–2.91), and medical history of anxiety (OR 1.90, 95%CI:1.12–3.24) and syncope (OR 2.75, 95%CI:1.45–5.22). Refraction decreased the likelihood of sporadic vision loss (OR 0.62, 95%CI:0.42–0.91). Conclusions Approximately 10% of CATT patients had sporadic vision loss. Baseline predictors included AMD-related factors and factors independent of AMD. These data are relevant for clinicians in practice and those involved in clinical trials. PMID:24727261

  20. Longitudinal comparison of visual acuity as measured by the ETDRS chart and by the potential acuity meter in eyes with macular edema, and its relationship with retinal thickness and sensitivity

    PubMed Central

    Hatef, E; Hanout, M; Moradi, A; Colantuoni, E; Bittencourt, M; Liu, H; Sepah, Y J; Ibrahim, M; Do, D V; Guyton, D L; Nguyen, Q D

    2014-01-01

    Purpose To evaluate the relationship between visual acuity as measured by the Early Treatment Diabetic Retinopathy Study (ETDRS) chart and by the potential acuity meter (PAM) with retinal thickness and sensitivity measured by a combined microperimetry/optical coherence tomography system (OCT). Methods Forty-four patients with macular edema (ME) were included in a prospective observational study. Visual acuity (VA) was assessed using the ETDRS chart (with best correction) as well as by the PAM. Retinal thickness and sensitivity was measured by an automatic fundus perimetry/tomography system. Results Best-corrected VA using the ETDRS chart ranged from 20/20 to 20/400 (median: 20/50). VA measured by the PAM without correction ranged from 20/20 to 20/400 (median: 20/40). The mean retinal thickness was 369.57 μm (s.d.: 140.28 μm) on spectral domain-OCT and the mean retinal sensitivity was 8.12 decibels (dB) (s.d.: 5.78 dB). The mean LogMAR value using the ETDRS chart was 0.43, whereas it was 0.38 using the PAM (P-value: 0.009). Conclusions VA values measured by the PAM were statistically significantly better than those measured by the ETDRS chart in eyes with ME secondary to various retinal vascular and uveitic diseases. VA measured by the PAM may be a more sensitive predictor of macular function than that obtained by ETDRS testing in eyes with ME. PMID:25104744

  1. Proteomic patterns analysis with multivariate calculations as a promising tool for prompt differentiation of early stage lung tissue with cancer and unchanged tissue material

    PubMed Central

    2011-01-01

    Background Lung cancer diagnosis in tissue material with commonly used histological techniques is sometimes inconvenient and in a number of cases leads to ambiguous conclusions. Frequently advanced immunostaining techniques have to be employed, yet they are both time consuming and limited. In this study a proteomic approach is presented which may help provide unambiguous pathologic diagnosis of tissue material. Methods Lung tissue material found to be pathologically changed was prepared to isolate proteome with fast and non selective procedure. Isolated peptides and proteins in ranging from 3.5 to 20 kDa were analysed directly using high resolution mass spectrometer (MALDI-TOF/TOF) with sinapic acid as a matrix. Recorded complex spectra of a single run were then analyzed with multivariate statistical analysis algorithms (principle component analysis, classification methods). In the applied protocol we focused on obtaining the spectra richest in protein signals constituting a pattern of change within the sample containing detailed information about its protein composition. Advanced statistical methods were to indicate differences between examined groups. Results Obtained results indicate changes in proteome profiles of changed tissues in comparison to physiologically unchanged material (control group) which were reflected in the result of principle component analysis (PCA). Points representing spectra of control group were located in different areas of multidimensional space and were less diffused in comparison to cancer tissues. Three different classification algorithms showed recognition capability of 100% regarding classification of examined material into an appropriate group. Conclusion The application of the presented protocol and method enabled finding pathological changes in tissue material regardless of localization and size of abnormalities in the sample volume. Proteomic profile as a complex, rich in signals spectrum of proteins can be expressed as a

  2. Higher-order aberrations and best-corrected visual acuity in Native American children with a high prevalence of astigmatism

    PubMed Central

    Miller, Joseph M.; Harvey, Erin M.; Schwiegerling, Jim

    2016-01-01

    Purpose To determine whether higher-order aberrations (HOAs) in children from a highly astigmatic population differ from population norms and whether HOAs are associated with astigmatism and reduced best-corrected visual acuity. Methods Subjects were 218 Tohono O’odham Native American children 5–9 years of age. Noncycloplegic HOA measurements were obtained with a handheld Shack-Hartmann sensor (SHS). Signed (z06s to z14s) and unsigned (z06u to z14u) wavefront aberration Zernike coefficients Z(3,−3) to Z(4,4) were rescaled for a 4 mm diameter pupil and compared to adult population norms. Cycloplegic refraction and best-corrected logMAR letter visual acuity (BCVA) were also measured. Regression analyses assessed the contribution of astigmatism (J0) and HOAs to BCVA. Results The mean root-mean-square (RMS) HOA of 0.191 ± 0.072 μm was significantly greater than population norms (0.100 ± 0.044 μm. All unsigned HOA coefficients (z06u to z14u) and all signed coefficients except z09s, z10s, and z11s were significantly larger than population norms. Decreased BCVA was associated with astigmatism (J0) and spherical aberration (z12u) but not RMS coma, with the effect of J0 about 4 times as great as z12u. Conclusions Tohono O’odham children show elevated HOAs compared to population norms. Astigmatism and unsigned spherical aberration are associated with decreased acuity, but the effects of spherical aberration are minimal and not clinically significant. PMID:26239206

  3. Outcomes of visual acuity in carbon ion radiotherapy: Analysis of dose-volume histograms and prognostic factors

    SciTech Connect

    Hasegawa, Azusa . E-mail: azusa@nirs.go.jp; Mizoe, Jun-etsu; Mizota, Atsushi; Tsujii, Hirohiko

    2006-02-01

    Purpose: To analyze the tolerance dose for retention of visual acuity in patients with head-and-neck tumors treated with carbon ion radiotherapy. Methods and Materials: From June 1994 to March 2000, 163 patients with tumors in the head and neck or skull base region were treated with carbon ion radiotherapy. Analysis was performed on 54 optic nerves (ONs) corresponding to 30 patients whose ONs had been included in the irradiated volume. These patients showed no evidence of visual impairment due to other factors and had a follow-up period of >4 years. All patients had been informed of the possibility of visual impairment before treatment. We evaluated the dose-complication probability and the prognostic factors for the retention of visual acuity in carbon ion radiotherapy, using dose-volume histograms and multivariate analysis. Results: The median age of 30 patients (14 men, 16 women) was 57.2 years. Median prescribed total dose was 56.0 gray equivalents (GyE) at 3.0-4.0 GyE per fraction per day (range, 48-64 GyE; 16-18 fractions; 4-6 weeks). Of 54 ONs that were analyzed, 35 had been irradiated with <57 GyE (maximum dose [D{sub max}]) resulting in no visual loss. Conversely, 11 of the 19 ONs (58%) irradiated with >57 GyE (D{sub max}) suffered a decrease of visual acuity. In all of these cases, the ONs had been involved in the tumor before carbon ion radiotherapy. In the multivariate analysis, a dose of 20% of the volume of the ON (D{sub 2}) was significantly associated with visual loss. Conclusions: The occurrence of visual loss seems to be correlated with a delivery of >60 GyE to 20% of the volume of the ON.

  4. Stroboscopic Goggles as a Countermeasure for Dynamic Visual Acuity and Landing Sickness After Long-Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Rosenberg, M. J. F.; Kreutzberg, G. A.; Peters, B. T.; Reschke, M. F.

    2017-01-01

    Gravity transitions cause changes in the vestibulo-occular reflex (VOR), which manifests as poor gaze control, a decrement in dynamic visual acuity (the ability to maintain gaze while in motion), both of which are caused by retinal slip. Retinal slip, the inability to keep an image focused on the retina, can drive or worsen sensory conflict, resulting in motion sickness (MS). Currently 100% of returning crewmembers report MS symptoms, which might affect their ability to perform mission critical tasks immediately after landing. Reschke et al. (2007) demonstrate that stroboscopic vision goggles improve motion sickness onset and symptom severity in motion sickness driven by retinal slip.

  5. Comparison of Visual Acuity in Reduced Lumination and Facility of Ocular Accommodation in Table Tennis Champions and Non- Players

    PubMed Central

    Jafarzadehpur, Ebrahim; Yarigholi, Mohammad R.

    2004-01-01

    A table tennis player should fixate at different distances; track the objects with different speed, and in different visual environment. Their visual skills must be well developed for these capabilities. Therefore, visual acuity in reduced lumination and facility of ocular accommodation those are two criteria for visual skills have been compared in table tennis players and normal non-players. Twenty-nine young table tennis champions and 29 normal matched non-players (did not take part in any racket sports game) were evaluated. Basic visual and eye examinations were done for both of them. Normal results in basic examination were fundamental requirement for all the subjects. +/-2.00 sphere lenses for accommodation facility are used. An electrical current regulator changed the output light intensity of a conventional chart projector (Topcon). Light intensity decreased to 10 cd·m-2 and visual acuity tested. In comparison of visual acuity in reduced lumination and facility of ocular accommodation in table tennis champions and non-players there are significant differences (p < 0.001). In the preliminary visual tests there was not any significant different in the two groups but the results in the top level table tennis player was very uniform and in every test and the standard deviation was lesser in tennis player group than non-players. These results show that motor and sensorial functions of expert players are well developed. That is consistent with other researchers. This result was interpreted as reflecting a better perceptual system of experts to the constraints encountered during table tennis and its use in practical settings for evaluating athletes or detecting sport talents. However some visual and perceptual training that usually used in orthoptics can be used for novice table tennis player to improve their abilities. Key Points That the ability of a champion depends on many sensory, motor and perceptual factors. Visual factors such as facility of accommodation

  6. "Far" and "Near" Visual Acuity While Walking and the Collective Contributions of Non-Ocular Mechanisms to Gaze Stabilization

    NASA Technical Reports Server (NTRS)

    Peters, Brian T.; vanEmmerik, Richard E. A.; Bloomberg, Jacob J.

    2006-01-01

    Gaze stabilization was quantified in subjects (n=11) as they walked on a motorized treadmill (1.8 m/s) and viewed visual targets at two viewing distances. A "far" target was positioned at 4 m (FAR) in front of the subject and the "near" target was placed at a distance of 0.5 m (NEAR). A direct measure of visual acuity was used to assess the overall effectiveness of the gaze stabilization system. The contributions of nonocular mechanisms to the gaze goal were also quantified using a measure of the distance between the subject and point in space where fixation of the visual target would require the least eye movement amplitude (i.e. the head fixation distance (HFD)). Kinematic variables mirrored those of previous investigations with the vertical trunk translation and head pitch signals, and the lateral translation and head yaw signals maintaining what appear as antiphase relationships. However, an investigation of the temporal relationships between the maxima and minima of the vertical translation and head pitch signals show that while the maximum in vertical translation occurs at the point of the minimum head pitch signal, the inverse is not true. The maximum in the head pitch signal lags the vertical translation minimum by an average of greater than 12 percent of the step cycle time. Three HFD measures, one each for data in the sagittal and transverse planes, and one that combined the movements from both planes, all revealed changes between the FAR and NEAR target viewing conditions. This reorganization of the nonocular degrees of freedom while walking was consistent with a strategy to reduce the magnitude of the eye movements required when viewing the NEAR target. Despite this reorganization, acuity measures show that image stabilization is not occurring while walking and viewing the NEAR target. Group means indicate that visual acuity is not affected while walking in the FAR condition, but a decrement of 0.15 logMAR (i.e. 1.5 eye chart lines) exists between the

  7. 7 CFR 160.29 - Containers to remain intact.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Containers to remain intact. 160.29 Section 160.29... STANDARDS FOR NAVAL STORES Analysis, Inspection, and Grading on Request § 160.29 Containers to remain intact... the containers holding such naval stores remain intact as sampled until the analysis,...

  8. Visual acuity and patient satisfaction at varied distances and lighting conditions after implantation of an aspheric diffractive multifocal one-piece intraocular lens

    PubMed Central

    Chang, Daniel H

    2016-01-01

    Purpose The aim of the study is to evaluate the visual acuity and patient satisfaction at varied distances under photopic and mesopic lighting conditions in patients bilaterally implanted with aspheric diffractive multifocal one-piece intraocular lenses. Methods In this retrospective–prospective study, 16 patients with a mean age of 66.2±9.2 years (range: 50–81 years) who had undergone bilateral phacoemulsification surgery with implantation of a Tecnis multifocal one-piece intraocular lens (ZMB00) were evaluated. Monocular and binocular uncorrected and distance-corrected visual acuities were measured at distance (20 ft), intermediate (70–80 cm), and near (35–40 cm) under photopic (85 cd/m2) and mesopic (3 cd/m2) lighting conditions and were compared using the paired t-test. All patients also completed a subjective questionnaire. Results At a mean follow-up of 9.5±3.9 months, distance, near, and intermediate visual acuity improved significantly from preoperative acuity. Under photopic and mesopic conditions, 93.8% and 62.5% of patients, respectively, had binocular uncorrected intermediate visual acuity of 20/40 or better, and 62.5% and 31.3% of patients had binocular uncorrected near visual acuity of 20/20 or better. All patients were satisfied with their overall vision without using glasses and/or contact lenses when compared with before surgery. A total of 87.5% of patients reported no glare and 68.8% of patients reported no halos around lights at night. Conclusion Tecnis multifocal one-piece intraocular lenses provide good distance, intermediate, and near visual acuity under photopic as well as mesopic lighting conditions. High levels of spectacle independence with low levels of photic phenomenon were achieved, resulting in excellent patient satisfaction. PMID:27536061

  9. Remaining Useful Life Estimation in Prognosis: An Uncertainty Propagation Problem

    NASA Technical Reports Server (NTRS)

    Sankararaman, Shankar; Goebel, Kai

    2013-01-01

    The estimation of remaining useful life is significant in the context of prognostics and health monitoring, and the prediction of remaining useful life is essential for online operations and decision-making. However, it is challenging to accurately predict the remaining useful life in practical aerospace applications due to the presence of various uncertainties that affect prognostic calculations, and in turn, render the remaining useful life prediction uncertain. It is challenging to identify and characterize the various sources of uncertainty in prognosis, understand how each of these sources of uncertainty affect the uncertainty in the remaining useful life prediction, and thereby compute the overall uncertainty in the remaining useful life prediction. In order to achieve these goals, this paper proposes that the task of estimating the remaining useful life must be approached as an uncertainty propagation problem. In this context, uncertainty propagation methods which are available in the literature are reviewed, and their applicability to prognostics and health monitoring are discussed.

  10. Intraocular pressure, retinal vascular, and visual acuity changes during 48 hours of 10-deg head-down tilt

    NASA Technical Reports Server (NTRS)

    Mader, Thomas H.; Taylor, Gerald R.; Hunter, Norwood; Caputo, Michael; Meehan, Richard T.

    1990-01-01

    Intraocular pressures, retinal vascular diameters, and visual acuities of nine men, were repeatedly measured while the subjects were tilted 10 deg head-down for 48 h and while they were seated before (baseline), and after the tilt. An immediate increase in intraocular pressure, measured by pneumatonometer was recorded when subjects assumed the head-down position, and diurnal variations in intraocular pressures were observed for the 48 h. The initial and final head-down intraocular pressures were not significantly different. However, when subjects resumed the sitting position, intraocular pressures fell below the initial sitting values. Computer image analysis of the retinal vasculature detected a 6 percent and 2 percent reduction in the caliber of arteries and veins, respectively, as compared with sitting baseline values. No changes in visual acuity were documented during the 48 h of head-down tilt. The data suggest that the choroidal blood reservoir increases in volume over 48 h at continuous head-down position with a compensatory decrease in aqueous volume. These findings may explain intraocular pressure changes noted in astronauts during previous space missions and in studies associated with change in body position.

  11. The Effect of 3D Visual Simulator on Children’s Visual Acuity - A Pilot Study Comparing Two Different Modalities

    PubMed Central

    Ide, Takeshi; Ishikawa, Mariko; Tsubota, Kazuo; Miyao, Masaru

    2013-01-01

    Purpose : To evaluate the efficacy of two non-surgical interventions of vision improvement in children. Methods : A prospective, randomized, pilot study to compare fogging method and the use of head mounted 3D display. Subjects were children, between 5 to 15 years old, with normal best corrected visual acuity (BCVA) and up to -3D myopia. Subjects played a video game as near point work, and received one of the two methods of treatments. Measurements of uncorrected far visual acuity (UCVA), refraction with autorefractometer, and subjective accommodative amplitude were taken 3 times, at the baseline, after the near work, and after the treatment. Results : Both methods applied after near work, improved UCVA. Head mounted 3D display group showed significant improvement in UCVA and resulted in better UCVA than baseline. Fogging group showed improvement in subjective accommodative amplitude. While 3D display group did not show change in the refraction, fogging group’s myopic refraction showed significant increase indicating the eyes showed myopic change of eyes after near work and treatment. Discussion : Despite our lack of clear knowledge in the mechanisms, both methods improved UCVA after the treatments. The improvement in UCVA was not correlated to measured refraction values. Conclusion : UCVA after near work can be improved by repeating near and distant accommodation by fogging and 3D image viewing, although at the different degrees. Further investigation on mechanisms of improvements and their clinical significance are warranted. PMID:24222810

  12. Comparison of energy expenditure during the Y-balance test in older adults with different visual acuities

    PubMed Central

    Shin, Sun-Shil; An, Duk-Hyun

    2015-01-01

    [Purpose] This study compared the energy expenditure during the Y-balance test (YBT) between elderly women with good binocular visual acuity (BVA) and those with poor BVA. [Subjects] Twenty-one elderly women who could walk independently were recruited from a community dwelling. Eleven participants had a BVA equal to or less than 0.4 logarithm of the minimum angle of resolution (logMAR), and the other 10 participants had a BVA equal to or better than 0.3 logMAR. [Methods] The participants had an accelerometer attached over the L3 spinous process for measurement of energy expenditure and performed the YBT in the anterior, posteromedial, and posterolateral directions. [Results] The normalized reach distance in the good BVA group during the YBT in three directions and composite reach distance were significantly longer compared with the values in the poor BVA group. The energy expenditure in the good BVA group during the YBT in the three directions was significantly reduced compared with the values in the poor BVA group. [Conclusion] We suggest that visual acuity in the elderly influences dynamic balance and energy expenditure. Elderly subjects with poor BVA showed poor dynamic balance control and an inefficient biomechanical cost strategy compared to subjects with good BVA. PMID:25931711

  13. Quantification of the outer retinal layers: correlation to visual acuity in healthy subjects and patients with central serous chorioretinopathy

    NASA Astrophysics Data System (ADS)

    Sander, Birgit; Christensen, Ulrik; Larsen, Michael; Jørgensen, Thomas M.

    2007-07-01

    Purpose: Quantification of outer retinal layers in humans. Method: 11 eyes in healthy subjects and 3 eyes in patients after resolution of central serous chorioretinopathy (CSCR). Multiple line scans were obtained using OCT Stratus and scans were registered and averaged to enhance contrast. The distance from the inner-outer segment junction to the posterior part of the retinal pigment epithelium (RPE-OS complex) was calculated. In addition, the reflectance of the outer photoreceptor layer in the foveal center was compared to that peripheral to the fovea. Results: Mean thickness of the RPE-OS complex in healthy subjects was 77.3 μm, in CSCR 52.9 μm. The thickness of the RPE-OS complex was significantly correlated to visual acuity (r=0.95, p<0.01). The ratio of reflectance (fovea/parafovea) was 1.06 in healthy subjects, 1.18 in CSCR eyes. Conclusion: The RPE-OS complex thickness was markedly reduced in eyes after resolution of CSCR and highly correlated to the visual acuity, the correlation to total foveal thickness was less. An increased backscatter was seen in CSCR, probably due to photoreceptor disorganization and atrophy.

  14. Change in visual acuity is well correlated with change in image-quality metrics for both normal and keratoconic wavefront errors.

    PubMed

    Ravikumar, Ayeswarya; Marsack, Jason D; Bedell, Harold E; Shi, Yue; Applegate, Raymond A

    2013-11-26

    We determined the degree to which change in visual acuity (VA) correlates with change in optical quality using image-quality (IQ) metrics for both normal and keratoconic wavefront errors (WFEs). VA was recorded for five normal subjects reading simulated, logMAR acuity charts generated from the scaled WFEs of 15 normal and seven keratoconic eyes. We examined the correlations over a large range of acuity loss (up to 11 lines) and a smaller, more clinically relevant range (up to four lines). Nine IQ metrics were well correlated for both ranges. Over the smaller range of primary interest, eight were also accurate and precise in estimating the variations in logMAR acuity in both normal and keratoconic WFEs. The accuracy for these eight best metrics in estimating the mean change in logMAR acuity ranged between ±0.0065 to ±0.017 logMAR (all less than one letter), and the precision ranged between ±0.10 to ±0.14 logMAR (all less than seven letters).

  15. Modelling of human low frequency sound localization acuity demonstrates dominance of spatial variation of interaural time difference and suggests uniform just-noticeable differences in interaural time difference.

    PubMed

    Smith, Rosanna C G; Price, Stephen R

    2014-01-01

    Sound source localization is critical to animal survival and for identification of auditory objects. We investigated the acuity with which humans localize low frequency, pure tone sounds using timing differences between the ears. These small differences in time, known as interaural time differences or ITDs, are identified in a manner that allows localization acuity of around 1° at the midline. Acuity, a relative measure of localization ability, displays a non-linear variation as sound sources are positioned more laterally. All species studied localize sounds best at the midline and progressively worse as the sound is located out towards the side. To understand why sound localization displays this variation with azimuthal angle, we took a first-principles, systemic, analytical approach to model localization acuity. We calculated how ITDs vary with sound frequency, head size and sound source location for humans. This allowed us to model ITD variation for previously published experimental acuity data and determine the distribution of just-noticeable differences in ITD. Our results suggest that the best-fit model is one whereby just-noticeable differences in ITDs are identified with uniform or close to uniform sensitivity across the physiological range. We discuss how our results have several implications for neural ITD processing in different species as well as development of the auditory system.

  16. The relationship between perifoveal achromatic, L- and M-cone acuity and retinal structure as assessed with multimodal high resolution imaging.

    PubMed

    Baraas, Rigmor C; Gjelle, Jon V B; Finstad, Elisabeth Bratlie; Jacobsen, Siri Bjørnetun; Gilson, Stuart J

    2016-07-02

    The relationships between perifoveal measures of achromatic-, L- and M-cone acuity and retinal structure were investigated in healthy young males. Thirty-two males, aged 20-39years, with normal foveal logMAR letter acuity and no observed ocular abnormalities participated in the study. Achromatic and isolated L- and M-cone spatial acuity was measured in the dominant eye with a Sloan E letter of 90% achromatic decrement contrast or 23% increment cone contrast, respectively. Separately, the central part of the same eye was imaged with high-resolution spectral-domain optical coherence tomography (SD-OCT) and adaptive optics ophthalmoscopy (AOO). Thickness measures and cone density in the fovea and parafoveal region were not correlated with perifoveal structural measures. A significant correlation was observed between thicker retinal pigment epithelium (RPE) complex, higher cone density and better L-cone logMAR at 5deg eccentricity, but not for achromatic or M-cone logMAR. The results imply that single letter perifoveal L-cone acuity, rather than achromatic acuity, may provide a useful measure for assessing the structure-function relationship and detecting early changes in the perifoveal cone mosaic.

  17. Sociodemographic correlates of visual acuity impairment in Hispanic children and adolescents.

    PubMed

    Lee, D J; Gomez-Marin, O; Lam, B L; Ma, F

    1999-10-01

    Sociodemographic correlates of visual impairment were examined in 6- to 19-year-old Hispanic children and adolescents using data from the Hispanic Health and Nutrition Examination Survey. Mexican American and Puerto Rican children whose parents had 0 to 6 years of education were more likely to remain visually impaired even when tested with their glasses or contact lenses, if any (i.e., with usual correction) than children whose parents reported 12 to 17 years of education. Mexican Americans residing below versus at or above the poverty line were more likely to remain visually impaired even with the usual correction. Mexican Americans enrolled in the Medicaid program or who were without health insurance were more likely to remain visually impaired than Mexican Americans with private health insurance. When tested without glasses or contact lenses, Cuban Americans and Mexican Americans born outside of the mainland United States had lower rates of visual impairment compared to those born in the United States; however, children in this latter group were more likely to remain visually impaired with usual correction than U.S.-born Mexican Americans. These findings suggest that Hispanic children from economically disadvantaged households and those born outside the United States may not be receiving optimal eye care that could improve visual function.

  18. Monocular Deprivation in Adult Mice Alters Visual Acuity and Single-Unit Activity

    ERIC Educational Resources Information Center

    Evans, Scott; Lickey, Marvin E.; Pham, Tony A.; Fischer, Quentin S.; Graves, Aundrea

    2007-01-01

    It has been discovered recently that monocular deprivation in young adult mice induces ocular dominance plasticity (ODP). This contradicts the traditional belief that ODP is restricted to a juvenile critical period. However, questions remain. ODP of young adults has been observed only using methods that are indirectly related to vision, and the…

  19. Five-year visual acuity outcomes and injection patterns in patients with pro-re-nata treatments for AMD, DME, RVO and myopic CNV

    PubMed Central

    Wecker, Thomas; Ehlken, Christoph; Bühler, Anima; Lange, Clemens; Agostini, Hansjürgen; Böhringer, Daniel; Stahl, Andreas

    2017-01-01

    Background Anti vascular endothelial growth factor (VEGF) therapy is an established treatment for various retinal diseases. Long-term data on injection frequencies and visual acuity (VA), however, are still rare. Methods Five-year analysis of real-life VA developments and injection patterns from 2072 patients (2577 eyes; 33 187 injections) with chronically active disease undergoing pro-re-nata treatment for age-related macular degeneration (AMD), diabetic macular oedema (DME), retinal vein occlusion (RVO) and myopic choroidal neovascularisation (CNV). Results Maximum mean VA gain in year 1 was+5.2 letters in AMD, +6.2 in DME, +10 in RVO and+7.2 in myopic CNV. Over 5 years, however, VA in patients with AMD declined. By year 5, 34% of patients with AMD had experienced VA loss of >15 letters, 56% had remained stable and 10% had gained >15 letters. Long-term VA developments in DME and RVO were more favourable with 81% of DME and 79% of patients with RVO gaining or maintaining vision at 5 years. In AMD, median injection frequency was six in year 1 and between four and five in consecutive years. In DME and RVO, median injection frequency was six in year 1 but lower compared with AMD in consecutive years. Injection frequency in DME was weakly associated with patient age (rs=0.1; p=0.03). Conclusions In AMD, the initial VA gain was not maintained long term despite higher injection numbers compared with DME, RVO and myopic CNV. The presented real-world data provide a peer-group-based estimate of VA developments and injection frequencies for counselling patients undergoing long-term anti-VEGF therapy. PMID:27215744

  20. HIV co-receptor tropism prediction remains stable over time in treatment-naïve patients.

    PubMed

    Philip, Keir Ej; Macartney, Malcolm J; Conibear, Tim Cr; Smith, Colette J; Marshall, Neal; Johnson, Margaret A; Haque, Tanzina; Webster, Daniel P

    2016-06-01

    HIV co-receptor tropism determination is essential before prescribing the CCR5 antagonist maraviroc. British HIV Association guidelines suggest tropism testing may remain valid for only 90 days in antiretroviral-naïve patients. We aimed to determine the accuracy of this figure. Tropism was assessed in 26 antiretroviral-naïve patients with ongoing viral replication, sampled yearly from first clinic visit. The V3 region of HIV-1 was sequenced in triplicate, then tropism predicted using the Geno2Pheno system. Baseline tropism prediction remained valid for a median of 52 months (range 7-81). For 19/26 individuals baseline tropism remained unchanged throughout a median of 54 months follow-up; 18 R5 tropic and 1 X4 tropic. In seven patients (27%) baseline tropism switched at least once (range 1-4 switches) during follow-up; however, their baseline tropism prediction remained valid for a median of 45 months. Co-receptor tropism in treatment-naïve patients with ongoing viral replication appears highly stable over time, suggesting that baseline genotypic tropism prediction may be valid for a longer duration in patients delaying ART initiation. In this study, baseline tropism prediction remained valid for a median of 52 months, suggesting current guidelines recommending repeat testing after 90 days may be excessively conservative in their assessment of tropism stability.

  1. Health Benefits In 2016: Family Premiums Rose Modestly, And Offer Rates Remained Stable.

    PubMed

    Claxton, Gary; Rae, Matthew; Long, Michelle; Damico, Anthony; Whitmore, Heidi; Foster, Gregory

    2016-10-01

    The annual Kaiser Family Foundation/Health Research and Educational Trust Employer Health Benefits Survey found that in 2016, average annual premiums (employer and worker contributions combined) were $6,435 for single coverage and $18,142 for family coverage. The family premium in 2016 was 3 percent higher than that in 2015. On average, workers contributed 18 percent of the premium for single coverage and 30 percent for family coverage. The share of firms offering health benefits (56 percent) and of workers covered by their employers' plans (62 percent) remained statistically unchanged from 2015. Employers continued to offer financial incentives for completing wellness or health promotion activities. Almost three in ten covered workers were enrolled in a high-deductible plan with a savings option-a significant increase from 2014. The 2016 survey included new questions on cost sharing for specialty drugs and on the prevalence of incentives for employees to seek care at alternative settings.

  2. Adherence to Occlusion Therapy in the First Six Months of Follow-Up and Visual Acuity among Participants in the Infant Aphakia Treatment Study (IATS)

    PubMed Central

    Drews-Botsch, Carolyn D.; Celano, Marianne; Kruger, Stacey; Hartmann, E. Eugenie

    2012-01-01

    Purpose. Achieving good vision in infants born with a unilateral cataract is believed to require early surgery and consistent occlusion of the fellow eye. This article examines the relationship between adherence to patching and grating acuity. Methods. Data came from the Infant Aphakia Treatment Study, a randomized clinical trial of treatment for unilateral congenital cataract. Infants were either left aphakic (n = 53) or had an intraocular lens implanted (n = 55). Patching was prescribed 1 hour per day per month of age until 8 months of age and 50% of waking hours thereafter. Adherence was measured as the mean percentage of prescribed patching reported in a 7-day diary completed 2 months after surgery, and 48-hour recall interviews conducted 3 and 6 months after surgery. Grating visual acuity was measured within 1 month of the infant's first birthday (n = 108) using Teller Acuity Cards by a tester masked to treatment. Nonparametric correlations were used to examine the relationship with grating acuity. Results. On average, caregivers reported patching 84.3% (SD = 31.2%) of prescribed time and adherence did not differ by treatment (t = −1.40, df = 106, p = 0.16). Adherence was associated with grating acuity (rSpearman = −0.27, p < 0.01), but more so among pseudophakic (rSpearman = −0.41, p < 0.01) than aphakic infants (rSpearman = −0.10, p = 0.49). Conclusions. This study empirically has shown that adherence to patching during the first 6 months after surgery is associated with better grating visual acuity at 12 months of age after treatment for unilateral cataract and that implanting an intraocular lens is not associated with adherence. (ClinicalTrials.gov number, NCT00212134.) PMID:22491410

  3. Tactile perception in blind Braille readers: a psychophysical study of acuity and hyperacuity using gratings and dot patterns.

    PubMed

    Grant, A C; Thiagarajah, M C; Sathian, K

    2000-02-01

    It is not clear whether the blind are generally superior to the sighted on measures of tactile sensitivity or whether they excel only on certain tests owing to the specifics of their tactile experience. We compared the discrimination performance of blind Braille readers and age-matched sighted subjects on three tactile tasks using precisely specified stimuli. Initially, the blind significantly outperformed the sighted at a hyperacuity task using Braille-like dot patterns, although, with practice, both groups performed equally well. On two other tasks, hyperacute discrimination of gratings that differed in ridge width and spatial-acuity-dependent discrimination of grating orientation, the performance of the blind did not differ significantly from that of sighted subjects. These results probably reflect the specificity of perceptual learning due to Braille-reading experience.

  4. The taphonomy of human remains in a glacial environment.

    PubMed

    Pilloud, Marin A; Megyesi, Mary S; Truffer, Martin; Congram, Derek

    2016-04-01

    A glacial environment is a unique setting that can alter human remains in characteristic ways. This study describes glacial dynamics and how glaciers can be understood as taphonomic agents. Using a case study of human remains recovered from Colony Glacier, Alaska, a glacial taphonomic signature is outlined that includes: (1) movement of remains, (2) dispersal of remains, (3) altered bone margins, (4) splitting of skeletal elements, and (5) extensive soft tissue preservation and adipocere formation. As global glacier area is declining in the current climate, there is the potential for more materials of archaeological and medicolegal significance to be exposed. It is therefore important for the forensic anthropologist to have an idea of the taphonomy in this setting and to be able to differentiate glacial effects from other taphonomic agents.

  5. 13. View South, showing the remaining pier footings for the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. View South, showing the remaining pier footings for the steam engine water tower for the Chesapeake and Ohio Railroad. - Cotton Hill Station Bridge, Spanning New River at State Route 16, Cotton Hill, Fayette County, WV

  6. 53. INTERIOR VIEW LOOKING NORTH NORTHEAST SHOWING THE REMAINS OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    53. INTERIOR VIEW LOOKING NORTH NORTHEAST SHOWING THE REMAINS OF A WOODEN SETTLING BOX IN THE BACKGROUND RIGHT. AMALGAMATING PANS IN THE FOREGROUND. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  7. View of submerged remains of Read Sawmill, showing floor boards, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of submerged remains of Read Sawmill, showing floor boards, cross beams and notches for wall post beams. - Silas C. Read Sawmill, Outlet of Maxwell Lake near North Range Road, Fort Gordon, Richmond County, GA

  8. View of submerged remains of Read Sawmill, showing floor boards, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of submerged remains of Read Sawmill, showing floor boards, wall boards, tenoned uprights and mortised sill beams. - Silas C. Read Sawmill, Outlet of Maxwell Lake near North Range Road, Fort Gordon, Richmond County, GA

  9. View of submerged remains of Read Sawmill, with floor boards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of submerged remains of Read Sawmill, with floor boards removed, showing cross beams, foundation sill and mortises, and horizontal wall boards. - Silas C. Read Sawmill, Outlet of Maxwell Lake near North Range Road, Fort Gordon, Richmond County, GA

  10. View of submerged remains of Read Sawmill with most floorboards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of submerged remains of Read Sawmill with most floorboards removed, showing cross beams with mortises, vertical wall boards, and horizontal floor boards. - Silas C. Read Sawmill, Outlet of Maxwell Lake near North Range Road, Fort Gordon, Richmond County, GA

  11. [The craniofacial identification of the remains from the Yekaterinburg burial].

    PubMed

    Abramov, S S

    1998-01-01

    Based on expert evaluation of remains of 7 members of Imperial Romanov family and 4 persons in their attendance, the author demonstrates methodological approaches to identification craniocephalic studies in cases with group burials.

  12. 4. Band Wheel and Walking Beam Mechanism, Including Remains of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Band Wheel and Walking Beam Mechanism, Including Remains of Frame Belt House, Looking Southeast - David Renfrew Oil Rig, East side of Connoquenessing Creek, 0.4 mile North of confluence with Thorn Creek, Renfrew, Butler County, PA

  13. Looking east inside of casthouse no. 6 at the remains ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking east inside of casthouse no. 6 at the remains of slag runner and slag notch of blast furnace no. 6. - U.S. Steel Edgar Thomson Works, Blast Furnace Plant, Along Monongahela River, Braddock, Allegheny County, PA

  14. 7. REMAINS OF PLANK WALL WITHIN CANAL CONSTRUCTED TO PROTECT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. REMAINS OF PLANK WALL WITHIN CANAL CONSTRUCTED TO PROTECT OUTSIDE CANAL BANK, LOOKING SOUTHWEST. NOTE CROSS SUPPORT POLES EXTENDING TO HILLSIDE. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO

  15. 6. REMAINS OF PLANK WALL NAILED TO POSTS WITHIN CANAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. REMAINS OF PLANK WALL NAILED TO POSTS WITHIN CANAL CONSTRUCTED TO PROTECT OUTSIDE CANAL BANK. VIEW IS TO THE WEST. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO

  16. 1. SOUTHWEST FRONT AND SOUTHEAST SIDE OF BLACKSMITH SHOP REMAINS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. SOUTHWEST FRONT AND SOUTHEAST SIDE OF BLACKSMITH SHOP REMAINS, TENANT HOUSE IN BACKGROUND - Mount Etna Iron Works, Blacksmith Shop, East of U.S. Route 22 on T.R. 463, Williamsburg, Blair County, PA

  17. 21. REMAINS OF HOP BAILING CHUTE ON SECOND FLOOR; THIS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. REMAINS OF HOP BAILING CHUTE ON SECOND FLOOR; THIS CHUTE EXTENDS TO THE GROUND FLOOR. - James W. Seavey Hop Driers, 0.6 mile East from junction of Highway 99 & Alexander Avenue, Corvallis, Benton County, OR

  18. 20. REMAINS OF HOP BAILING CHUTE ON GROUND FLOOR; THIS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. REMAINS OF HOP BAILING CHUTE ON GROUND FLOOR; THIS CHUTE EXTENDS TO THE SECOND FLOOR. - James W. Seavey Hop Driers, 0.6 mile East from junction of Highway 99 & Alexander Avenue, Corvallis, Benton County, OR

  19. 21. Detail of remains of machinery house viewed from below ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Detail of remains of machinery house viewed from below anchor-span deck, showing drawspan cable running back to the winding drum of the winch; view to northeast. - Summer Street Bridge, Spanning Reserved Channel, Boston, Suffolk County, MA

  20. 11. LOOKING SOUTH AT THE ONLY REMAINING PART OF THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. LOOKING SOUTH AT THE ONLY REMAINING PART OF THE NORTH SIDE OF ORIGINAL LAB, FROM COURTYARD. - U.S. Geological Survey, Rock Magnetics Laboratory, 345 Middlefield Road, Menlo Park, San Mateo County, CA

  1. 11. Remains of Douglasfir cordwood abandoned when kilns ceased operation, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Remains of Douglas-fir cordwood abandoned when kilns ceased operation, looking northeast. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID

  2. 25. CAFETERIA Note remains of tile floor in foreground. Food ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. CAFETERIA Note remains of tile floor in foreground. Food cooked on the stove was served to workers in the eating area to the left of the counter (off picture). - Hovden Cannery, 886 Cannery Row, Monterey, Monterey County, CA

  3. 3. INTERIOR OF THE WATER FILTRATION PLANT SHOWING REMAINS OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. INTERIOR OF THE WATER FILTRATION PLANT SHOWING REMAINS OF THE FILTRATION APPARATUS. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA

  4. 60. NORTHEASTERN VIEW OF THE REMAINS OF THE DOROTHY SIX ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. NORTHEASTERN VIEW OF THE REMAINS OF THE DOROTHY SIX BLAST FURNACE COMPLEX. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  5. 59. REMAINS OF THE DOROTHY SIX BLAST FURNACE COMPLEX LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    59. REMAINS OF THE DOROTHY SIX BLAST FURNACE COMPLEX LOOKING NORTHEAST. THE LADLE HOUSE IS ON THE RIGHT. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  6. 1. VIEW SHOWING REMAINS OF CAMOUFLAGE COVERING CONCRETE FOOTING FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW SHOWING REMAINS OF CAMOUFLAGE COVERING CONCRETE FOOTING FOR A GENERATOR PAD - Fort Cronkhite, Anti-Aircraft Battery No. 1, Concrete Footing-Generator Pad, Wolf Road, Sausalito, Marin County, CA

  7. 15. DETAIL VIEW, AT STREET LEVEL, OF REMAINING STONE POST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. DETAIL VIEW, AT STREET LEVEL, OF REMAINING STONE POST ON NORTH SIDE, STONE WALL AND METAL RAILING ON SOUTH SIDE, LOOKING SOUTHEAST - Lake Street Bridge, Spanning Ruddiman Creek at Lake Shore Drive, Muskegon, Muskegon County, MI

  8. Ankle proprioceptive acuity is associated with objective as well as self-report measures of balance, mobility, and physical function.

    PubMed

    Deshpande, Nandini; Simonsick, Eleanor; Metter, E Jeffrey; Ko, Seunguk; Ferrucci, Luigi; Studenski, Stephanie

    2016-06-01

    Ankle proprioceptive information is integrated by the central nervous system to generate and modulate muscle contractions for maintaining standing balance. This study evaluated the association of ankle joint proprioception with objective and self-report measures of balance, mobility, and physical function across the adult life span. Seven hundred and ninety participants (age range 24-97 years, 362 women) who completed ankle proprioception assessment between 2010 and 2014 were included in the present study from the population-based cohort of the Baltimore Longitudinal Study of Aging (BLSA), USA. Outcome measures included ankle joint proprioception measured as threshold for perception of passive movement (TPPM); single leg stance time; perceived difficulty for standing balance; usual, fastest, and narrow-path gait speed; walking index; short physical performance battery score; and self-reported activity restriction due to fear of falling. Descriptive variables included age, sex, body mass index, education, strength, and cognition. Analyses of covariance (ANCOVA) in general linear model (GLM) or multinomial logistic regression analyses were performed, as appropriate, to test the hypothesis that balance, mobility, and physical function were significantly different according to TPPM quintiles even after adjusting for relevant covariates. Those with TPPM >2.2° consistently demonstrated poor balance, mobility, and physical function. However, with increase in challenge (single leg stance, fastest walking speed, and SPPB), TPPM >1.4° was associated with significantly worse performance. In conclusion, ankle proprioceptive acuity has an overall graded relationship with objective and self-report measures of balance, mobility, and physical function. However, the cutoff proprioceptive acuity associated with substantial decline or inability to perform could depend on the challenge induced.

  9. Low contrast visual acuity testing is associated with cognitive performance in multiple sclerosis: a cross-sectional pilot study

    PubMed Central

    2013-01-01

    Background Cognitive impairment and visual deterioration are two key clinical symptoms in MS and affect 50 to 80% of patients. Little is known about the influence of cognitive impairment on visual tests recommended for MS such as low contrast sensitivity testing. Our objective was to investigate whether low contrast sensitivity testing is influenced by cognitive impairment in multiple sclerosis (MS) patients. Methods Cross-sectional study including 89 patients with relapsing-remitting MS. All patients received cognitive evaluation using Rao’s Brief Repeatable Battery of Neuropsychological Testing (BRB-N). Visual assessments included low contrast sensitivity (CS) by functional acuity contrast testing and high contrast visual acuity (VA) using ETDRS charts. Retinal morphology as visual impairment correlate was measured using retinal nerve fiber layer (RNFL) thickness by optical coherence tomography. Results In combined analyses using generalized estimating equation models, Paced Auditory Serial Addition Test (PASAT) and RNFL as well as and the Symbol Digit Modalities Test (SDMT) and RNFL predicted CS. To further control for a potential influence of the anterior visual system we performed partial correlation analyses between visual function and cognitive function test results but controlling for RNFL. Even when controlling for RNFL, CS was associated with PASAT performance and SDMT performance. Conclusion Our data show that: a) cognitive impairment and performance in visual function tests such as low contrast sensitivity testing are associated; b) the main cognitive domains correlating with visual test performance are information processing speed and, to a lesser degree, memory; This preliminary data needs to be substantiated in further studies investigating patients with a higher cognitive burden, healthy controls and in longitudinal settings. PMID:24206900

  10. Presbyopia: a pilot investigation of the barriers and benefits of near visual acuity correction among a rural Filipino population

    PubMed Central

    2014-01-01

    Background Presbyopia is the age-related decline in accommodation that diminishes the ability of the eye to focus on near objects. Presbyopia is common and easy to correct; however, many communities lack access to basic eye care. The purpose of this project was to assess the burden of uncorrected presbyopia in a rural Filipino population and to pilot an intervention aimed at increasing access to reading glasses in the community. Methods Individuals above the age of 40 who presented to a health outreach in the Philippines were invited to undergo a near vision exam to detect the presence of functional presbyopia and be fitted with ready-made, single-vision glasses. The change in stereoacuity was used as a surrogate measure of functional improvement after near vision correction. A questionnaire was administered to assess this population’s perceived barriers and benefits to correcting near vision. Results The average age of the participants was 57 ± 11 years, with 87.6% of participants having an uncorrected near visual acuity of <20/50. Reading glasses improved near vision to 20/40 or better in 77.7% of participants having near-vision impairment (uncorrected near visual acuity of <20/40). Over 75% of participants also showed improvement in stereoacuity. Cost, rather than availability, was perceived to be the greater barrier to the procurement of glasses, and 84% of participants reported that the glasses dispensed would greatly improve their ability to earn a living. Conclusions Dispensing ready-made, single-vision glasses is a simple and cost-effective intervention to improve near vision and enhance depth perception. A greater understanding of the barriers and benefits to correcting near vision will inform the design and execution of a sustainable program to correct presbyopia in developing countries. PMID:24467667

  11. The Slopes Remain the Same: Reply to Wolfe (2016)

    PubMed Central

    2016-01-01

    Wolfe (2016) responds to my article (Kristjánsson, 2015), arguing among other things, that the differences in slope by response method in my data reflect speed accuracy trade-offs. But when reaction times and errors are combined in one score (inverse efficiency) to sidestep speed accuracy trade-offs, slope differences still remain. The problem that slopes, which are thought to measure search speed, differ by response type therefore remains. PMID:27872743

  12. 52. VIEW OF REMAINS OF ORIGINAL 1907 CONTROL PANEL, LOCATED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. VIEW OF REMAINS OF ORIGINAL 1907 CONTROL PANEL, LOCATED ON NORTH WALL OF EAST END OF CONTROL ROOM. PORTIONS OF THIS PANEL REMAINED IN USE UNTIL THE PLANT CLOSED. THE METERS AND CONTROLS ARE MOUNTED ON SOAPSTONE PANELS. THE INSTRUMENT IN THE LEFT CENTER OF THE PHOTOGRAPH IS A TIRRILL VOLTAGE REGULATOR. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  13. A non-destructive method for dating human remains

    USGS Publications Warehouse

    Lail, Warren K.; Sammeth, David; Mahan, Shannon; Nevins, Jason

    2013-01-01

    The skeletal remains of several Native Americans were recovered in an eroded state from a creek bank in northeastern New Mexico. Subsequently stored in a nearby museum, the remains became lost for almost 36 years. In a recent effort to repatriate the remains, it was necessary to fit them into a cultural chronology in order to determine the appropriate tribe(s) for consultation pursuant to the Native American Grave Protection and Repatriation Act (NAGPRA). Because the remains were found in an eroded context with no artifacts or funerary objects, their age was unknown. Having been asked to avoid destructive dating methods such as radiocarbon dating, the authors used Optically Stimulated Luminescence (OSL) to date the sediments embedded in the cranium. The OSL analyses yielded reliable dates between A.D. 1415 and A.D. 1495. Accordingly, we conclude that the remains were interred somewhat earlier than A.D. 1415, but no later than A.D. 1495. We believe the remains are from individuals ancestral to the Ute Mouache Band, which is now being contacted for repatriation efforts. Not only do our methods contribute to the immediate repatriation efforts, they provide archaeologists with a versatile, non-destructive, numerical dating method that can be used in many burial contexts.

  14. Local interactions influence the fibrillation kinetics, structure and dynamics of Aβ(1-40) but leave the general fibril structure unchanged.

    PubMed

    Adler, Juliane; Scheidt, Holger A; Krüger, Martin; Thomas, Lars; Huster, Daniel

    2014-04-28

    A series of peptide mutants was studied to understand the influence of local physical interactions on the fibril formation mechanism of amyloid β (Aβ)(1-40). In the peptide variants, the well-known hydrophobic contact between residues phenylalanine 19 and leucine 34 was rationally modified. In single site mutations, residue phenylalanine 19 was replaced by amino acids that introduce higher structural flexibility by a glycine mutation or restrict the backbone flexibility by introduction of proline. Next, the aromatic phenylalanine was replaced by tyrosine or tryptophan, respectively, to probe the influence of additional hydrogen bond forming capacity in the fibril interior. Furthermore, negatively charged glutamate or positively charged lysine was introduced to probe the influence of electrostatics. In double mutants, the hydrophobic contact was replaced by a putative salt bridge (glutamate and lysine) or two electrostatically repelling lysine residues. The influence of these mutations on the fibrillation kinetics and morphology, cross-β structure as well as the local structure and dynamics was probed using fluorescence, transmission electron microscopy, X-ray diffraction, and solid-state NMR spectroscopy. While the fibrillation kinetics and the local structure and dynamics of the peptide variants were influenced by the introduction of these local fields, the overall morphology and cross-β structure of the fibrils remained very robust against all the probed interactions. Overall, 7 out of the 8 mutated peptides formed fibrils of very similar morphology compared to the wildtype. However, characteristic local structural and dynamical changes indicate that amyloid fibrils show an astonishing ability to respond to local perturbations but overall show a very homogenous mesoscopic organization.

  15. FAR and NEAR Target Dynamic Visual Acuity: A Functional Assessment of Canal and Otolith Performance

    NASA Technical Reports Server (NTRS)

    Peters, Brian T.; Brady, Rachel A.; Landsness, Eric C.; Black, F. Owen; Bloomberg, Jacob J.

    2004-01-01

    Upon their return to earth, astronauts experience the effects of vestibular adaptation to microgravity. The postflight changes in vestibular information processing can affect postural and locomotor stability and may lead to oscillopsia during activities of daily living. However, it is likely that time spent in microgravity affects canal and otolith function differently. As a result, the isolated rotational stimuli used in traditional tests of canal function may fail to identify vestibular deficits after spaceflight. Also, the functional consequences of deficits that are identified often remain unknown. In a gaze control task, the relative contributions of the canal and otolith organs are modulated with viewing distance. The ability to stabilize gaze during a perturbation, on visual targets placed at different distances from the head may therefore provide independent insight into the function of this systems. Our goal was to develop a functional measure of gaze control that can also offer independent information about the function of the canal and otolith organs.

  16. Identification of the remains of King Richard III.

    PubMed

    King, Turi E; Fortes, Gloria Gonzalez; Balaresque, Patricia; Thomas, Mark G; Balding, David; Maisano Delser, Pierpaolo; Neumann, Rita; Parson, Walther; Knapp, Michael; Walsh, Susan; Tonasso, Laure; Holt, John; Kayser, Manfred; Appleby, Jo; Forster, Peter; Ekserdjian, David; Hofreiter, Michael; Schürer, Kevin

    2014-12-02

    In 2012, a skeleton was excavated at the presumed site of the Grey Friars friary in Leicester, the last-known resting place of King Richard III. Archaeological, osteological and radiocarbon dating data were consistent with these being his remains. Here we report DNA analyses of both the skeletal remains and living relatives of Richard III. We find a perfect mitochondrial DNA match between the sequence obtained from the remains and one living relative, and a single-base substitution when compared with a second relative. Y-chromosome haplotypes from male-line relatives and the remains do not match, which could be attributed to a false-paternity event occurring in any of the intervening generations. DNA-predicted hair and eye colour are consistent with Richard's appearance in an early portrait. We calculate likelihood ratios for the non-genetic and genetic data separately, and combined, and conclude that the evidence for the remains being those of Richard III is overwhelming.

  17. Identification of the remains of King Richard III

    PubMed Central

    King, Turi E.; Fortes, Gloria Gonzalez; Balaresque, Patricia; Thomas, Mark G.; Balding, David; Delser, Pierpaolo Maisano; Neumann, Rita; Parson, Walther; Knapp, Michael; Walsh, Susan; Tonasso, Laure; Holt, John; Kayser, Manfred; Appleby, Jo; Forster, Peter; Ekserdjian, David; Hofreiter, Michael; Schürer, Kevin

    2014-01-01

    In 2012, a skeleton was excavated at the presumed site of the Grey Friars friary in Leicester, the last-known resting place of King Richard III. Archaeological, osteological and radiocarbon dating data were consistent with these being his remains. Here we report DNA analyses of both the skeletal remains and living relatives of Richard III. We find a perfect mitochondrial DNA match between the sequence obtained from the remains and one living relative, and a single-base substitution when compared with a second relative. Y-chromosome haplotypes from male-line relatives and the remains do not match, which could be attributed to a false-paternity event occurring in any of the intervening generations. DNA-predicted hair and eye colour are consistent with Richard’s appearance in an early portrait. We calculate likelihood ratios for the non-genetic and genetic data separately, and combined, and conclude that the evidence for the remains being those of Richard III is overwhelming. PMID:25463651

  18. Forensic considerations when dealing with incinerated human dental remains.

    PubMed

    Reesu, Gowri Vijay; Augustine, Jeyaseelan; Urs, Aadithya B

    2015-01-01

    Establishing the human dental identification process relies upon sufficient post-mortem data being recovered to allow for a meaningful comparison with ante-mortem records of the deceased person. Teeth are the most indestructible components of the human body and are structurally unique in their composition. They possess the highest resistance to most environmental effects like fire, desiccation, decomposition and prolonged immersion. In most natural as well as man-made disasters, teeth may provide the only means of positive identification of an otherwise unrecognizable body. It is imperative that dental evidence should not be destroyed through erroneous handling until appropriate radiographs, photographs, or impressions can be fabricated. Proper methods of physical stabilization of incinerated human dental remains should be followed. The maintenance of integrity of extremely fragile structures is crucial to the successful confirmation of identity. In such situations, the forensic dentist must stabilise these teeth before the fragile remains are transported to the mortuary to ensure preservation of possibly vital identification evidence. Thus, while dealing with any incinerated dental remains, a systematic approach must be followed through each stage of evaluation of incinerated dental remains to prevent the loss of potential dental evidence. This paper presents a composite review of various studies on incinerated human dental remains and discusses their impact on the process of human identification and suggests a step by step approach.

  19. Characterization of the volatile organic compounds present in the headspace of decomposing animal remains, and compared with human remains.

    PubMed

    Cablk, Mary E; Szelagowski, Erin E; Sagebiel, John C

    2012-07-10

    Human Remains Detection (HRD) dogs can be a useful tool to locate buried human remains because they rely on olfactory rather than visual cues. Trained specifically to locate deceased humans, it is widely believed that HRD dogs can differentiate animal remains from human remains. This study analyzed the volatile organic compounds (VOCs) present in the headspace above partially decomposed animal tissue samples and directly compared them with results published from human tissues using established solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) methods. Volatile organic compounds present in the headspace of four different animal tissue samples (bone, muscle, fat and skin) from each of cow, pig and chicken were identified and compared to published results from human samples. Although there were compounds common to both animal and human remains, the VOC signatures of each of the animal remains differed from those of humans. Of particular interest was the difference between pigs and humans, because in some countries HRD dogs are trained on pig remains rather than human remains. Pig VOC signatures were not found to be a subset of human; in addition to sharing only seven of thirty human-specific compounds, an additional nine unique VOCs were recorded from pig samples which were not present in human samples. The VOC signatures from chicken and human samples were most similar sharing the most compounds of the animals studied. Identifying VOCs that are unique to humans may be useful to develop human-specific training aids for HRD canines, and may eventually lead to an instrument that can detect clandestine human burial sites.

  20. Quantitative visual psychophysics during the period of European enlightenment. The studies of the astronomer and mathematician Tobias Mayer (1723-1762) on visual acuity and colour perception.

    PubMed

    Grüsser, O J

    1989-02-01

    During the sixth decade of the 18th century, Tobias Mayer, Professor of Astronomy and Applied Mathematics (Economy) at the University of Göttingen, performed two investigations on quantitative visual psychophysics. He deduced a power law for the dependence of visual acuity on the intensity of light by which the stimulus pattern was illuminated. In his measurements he compared visual acuity determined with single black dots and visual acuity measured with gratings or checkerboard patterns; the latter he considered as the "real" measurement of visual acuity. Mayer also developed a three-dimensional hexaedric colour space from the definition of subtractive colour mixtures of three primary pigments (red, yellow, blue). This colour space can be considered as the predecessor of the later colour tables of Ostwald and Munsell. Mayer gave a simple quantitative description of each of the 819 hues in his colour space. Both psychophysical studies developed out of Mayer's interest in practical problems in astronomy and cartography. Mayer's main scientific merits were in the field of astronomy and mathematical geography. His psychophysical studies were performed in the spirit of enlightenment with the a priori assumption that the performance of the human perceptual machinery can be measured quantitatively and that the results are adequately expressed by mathematical rules. Mayer's achievements in the fields of mathematics, physics, astronomy and cartography were recently summarized by the extensive historical research of G.F. Forbes. In the present report a short biographical note precedes the description of Mayer's psychophysical studies.

  1. Impact of Zernike-fit error on simulated high- and low-contrast acuity in keratoconus: implications for using Zernike-based corrections

    NASA Astrophysics Data System (ADS)

    Marsack, Jason D.; Pesudovs, Konrad; Sarver, Edwin J.; Applegate, Raymond A.

    2006-04-01

    This study examines the extent to which a Zernike-based optical correction can restore acuity in keratoconus as a function of disease severity and contrast level. Increasingly complete Zernike corrections in the presence of Zernike-fit error were simulated. Acuity for keratoconic eyes with <60 D maximum corneal power reached 20/13 with a fifth-order Zernike correction under high-contrast conditions and exhibited a loss of 0.1 logMAR (minimum angle of resolution) (from 20/32 to 20/40) for low-contrast conditions. Acuity for keratoconic eyes with >60 D maximum corneal power approached 20/13 with sixth-tenth-order corrections under high-contrast conditions but did not return to similar levels with a tenth-order correction for low-contrast conditions. The results suggest that fit error affects visual performance for more difficult tasks and that restoring high-contrast acuity (20/16 or better) using a fifth-order Zernike correction is not limited by Zernike-fit error for over 88% of keratoconus cases.

  2. Learning to Identify Near-Acuity Letters, either with or without Flankers, Results in Improved Letter Size and Spacing Limits in Adults with Amblyopia

    PubMed Central

    Chung, Susana T. L.; Li, Roger W.; Levi, Dennis M.

    2012-01-01

    Amblyopia is a developmental abnormality that results in deficits for a wide range of visual tasks, most notably, the reduced ability to see fine details, the loss in contrast sensitivity especially for small objects and the difficulty in seeing objects in clutter (crowding). The primary goal of this study was to evaluate whether crowding can be ameliorated in adults with amblyopia through perceptual learning using a flanked letter identification task that was designed to reduce crowding, and if so, whether the improvements transfer to untrained visual functions: visual acuity, contrast sensitivity and the size of visual span (the amount of information obtained in one fixation). To evaluate whether the improvements following this training task were specific to training with flankers, we also trained another group of adult observers with amblyopia using a single letter identification task that was designed to improve letter contrast sensitivity, not crowding. Following 10,000 trials of training, both groups of observers showed improvements in the respective training task. The improvements generalized to improved visual acuity, letter contrast sensitivity, size of the visual span, and reduced crowding. The magnitude of the improvement for each of these measurements was similar in the two training groups. Perceptual learning regimens aimed at reducing crowding or improving letter contrast sensitivity are both effective in improving visual acuity, contrast sensitivity for near-acuity objects and reducing the crowding effect, and could be useful as a clinical treatment for amblyopia. PMID:22558234

  3. Microscopic residues of bone from dissolving human remains in acids.

    PubMed

    Vermeij, Erwin; Zoon, Peter; van Wijk, Mayonne; Gerretsen, Reza

    2015-05-01

    Dissolving bodies is a current method of disposing of human remains and has been practiced throughout the years. During the last decade in the Netherlands, two cases have emerged in which human remains were treated with acid. In the first case, the remains of a cremated body were treated with hydrofluoric acid. In the second case, two complete bodies were dissolved in a mixture of hydrochloric and sulfuric acid. In both cases, a great variety of evidence was collected at the scene of crime, part of which was embedded in resin, polished, and investigated using SEM/EDX. Apart from macroscopic findings like residual bone and artificial teeth, in both cases, distinct microscopic residues of bone were found as follows: (partly) digested bone, thin-walled structures, and recrystallized calcium phosphate. Although some may believe it is possible to dissolve a body in acid completely, at least some of these microscopic residues will always be found.

  4. Osteometric sex determination of burned human skeletal remains.

    PubMed

    Gonçalves, D; Thompson, T J U; Cunha, E

    2013-10-01

    Sex determination of human burned skeletal remains is extremely hard to achieve because of heat-related fragmentation, warping and dimensional changes. In particular, the latter is impeditive of osteometric analyses that are based on references developed on unburned bones. New osteometric references were thus obtained which allow for more reliable sex determinations. The calcined remains of cremated Portuguese individuals were examined and specific standard measurements of the humerus, femur, talus and calcaneus were recorded. This allowed for the compilation of new sex discriminating osteometric references which were then tested on independent samples with good results. Both the use of simple section points and of logistic regression equations provided successful sex classification scores. These references may now be used for the sex determination of burned skeletons. Its reliability is highest for contemporary Portuguese remains but nonetheless these results have important repercussion for forensic research. More conservative use of these references may also prove valuable for other populations as well as for archaeological research.

  5. Classification of pelvic ring fractures in skeletonized human remains.

    PubMed

    Báez-Molgado, Socorro; Bartelink, Eric J; Jellema, Lyman M; Spurlock, Linda; Sholts, Sabrina B

    2015-01-01

    Pelvic ring fractures are associated with high rates of mortality and thus can provide key information about circumstances surrounding death. These injuries can be particularly informative in skeletonized remains, yet difficult to diagnose and interpret. This study adapted a clinical system of classifying pelvic ring fractures according to their resultant degree of pelvic stability for application to gross human skeletal remains. The modified Tile criteria were applied to the skeletal remains of 22 individuals from the Cleveland Museum of Natural History and Universidad Nacional Autónoma de México that displayed evidence of pelvic injury. Because these categories are tied directly to clinical assessments concerning the severity and treatment of injuries, this approach can aid in the identification of manner and cause of death, as well as interpretations of possible mechanisms of injury, such as those typical in car-to-pedestrian and motor vehicle accidents.

  6. Decay rates of human remains in an arid environment.

    PubMed

    Galloway, A; Birkby, W H; Jones, A M; Henry, T E; Parks, B O

    1989-05-01

    The environment of southern Arizona with mild winters and hot, dry summers produces great variability in decay rates of human remains. Summer temperatures, which range well over 38 degrees C (100 degrees F), induce rapid bloating as a result of the accumulation of decompositional gases. However, in certain circumstances, the aridity can lead to extensive mummification, allowing preservation of remains for hundreds of years. A retrospective study of 189 cases, concentrating on remains found on the desert floor or in the surrounding mountains and on remains found within closed structures, outlines the time frame and sequences of the decay process. Remains can retain a fresh appearance for a considerable time in the winter, but the onset of marked decomposition is rapid in the summer months. Bloating of the body usually is present two to seven days following death. Following this, within structures, there is frequently rapid decomposition and skeletonization. With outdoor exposure, remains are more likely to pass through a long period of dehydration of outer tissues, mummification, and reduction of desiccated tissue. Exposure of large portions of the skeleton usually does not occur until four to six months after death. Bleaching and exfoliation of bone--the beginning stages of destruction of the skeletal elements--begins at about nine months' exposure. Insect activity, including that of maggot and beetle varieties, may accelerate decomposition, but this process is greatly affected by location of the body, seasonal weather, and accessibility of the soft tissues. Carnivores and other scavengers also are contributing factors, as are clothing or covering of the body, substrate, elevation, and latitude.

  7. Intolerance of uncertainty in emotional disorders: What uncertainties remain?

    PubMed

    Shihata, Sarah; McEvoy, Peter M; Mullan, Barbara Ann; Carleton, R Nicholas

    2016-06-01

    The current paper presents a future research agenda for intolerance of uncertainty (IU), which is a transdiagnostic risk and maintaining factor for emotional disorders. In light of the accumulating interest and promising research on IU, it is timely to emphasize the theoretical and therapeutic significance of IU, as well as to highlight what remains unknown about IU across areas such as development, assessment, behavior, threat and risk, and relationships to cognitive vulnerability factors and emotional disorders. The present paper was designed to provide a synthesis of what is known and unknown about IU, and, in doing so, proposes broad and novel directions for future research to address the remaining uncertainties in the literature.

  8. OVERVIEW OF REMAINS OF DEWATERING BUILDING, LOOKING SOUTH TOWARD CYANIDE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OVERVIEW OF REMAINS OF DEWATERING BUILDING, LOOKING SOUTH TOWARD CYANIDE PROCESSING AREA. WATER USED IN PROCESSING AT THE STAMP MILL WAS CIRCULATED HERE FOR RECLAMATION. SANDS WERE SETTLED OUT AND DEPOSITED IN ONE OF TWO TAILINGS HOLDING AREAS. CLEARED WATER WAS PUMPED BACK TO THE MILL FOR REUSE. THIS PROCESS WAS ACCOMPLISHED BY THE USE OF SETTLING CONES, EIGHT FEET IN DIAMETER AND SIX FEET HIGH. THE REMAINS OF FOUR CONES ARE AT CENTER, BEHIND THE TANK IN THE FOREGROUND. TO THE LEFT IS THE MAIN ACCESS ROAD BETWEEN THE MILL AND THE PARKING LOT. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  9. Acuity of a Cryptochrome and Vision-Based Magnetoreception System in Birds

    PubMed Central

    Solov'yov, Ilia A.; Mouritsen, Henrik; Schulten, Klaus

    2010-01-01

    Abstract The magnetic compass of birds is embedded in the visual system and it has been hypothesized that the primary sensory mechanism is based on a radical pair reaction. Previous models of magnetoreception have assumed that the radical pair-forming molecules are rigidly fixed in space, and this assumption has been a major objection to the suggested hypothesis. In this article, we investigate theoretically how much disorder is permitted for the radical pair-forming, protein-based magnetic compass in the eye to remain functional. Our study shows that only one rotational degree of freedom of the radical pair-forming protein needs to be partially constrained, while the other two rotational degrees of freedom do not impact the magnetoreceptive properties of the protein. The result implies that any membrane-associated protein is sufficiently restricted in its motion to function as a radical pair-based magnetoreceptor. We relate our theoretical findings to the cryptochromes, currently considered the likeliest candidate to furnish radical pair-based magnetoreception. PMID:20655831

  10. Determinants of visual acuity outcomes in eyes with neovascular AMD treated with anti-VEGF agents: an instrumental variable analysis of the AURA study.

    PubMed

    Holz, F G; Tadayoni, R; Beatty, S; Berger, A R; Cereda, M G; Hykin, P; Staurenghi, G; Wittrup-Jensen, K; Nilsson, J; Kim, K; Sivaprasad, S

    2016-08-01

    PurposeTo identify the strongest variable(s) linked with the number of ranibizumab injections and outcomes in AURA, and to identify ways to improve outcomes using this association.MethodsAURA was a large observational study that monitored visual acuity over a 2-year period in patients with neovascular age-related macular degeneration (AMD) who received ranibizumab injections. Baseline characteristics, resource use, and outcomes were analyzed using an instrumental variable approach and regression analysis.ResultsData were analyzed from 2227 patients enrolled in AURA. Optical coherence tomography (OCT) and ophthalmoscopy were the most common diagnostic tests used, and this combination was the strongest instrumental variable. Use of OCT and ophthalmoscopy affected the number of injections given and resulted in an increase in visual acuity gains from baseline of 17.6 letters in year 1 and 2.5 letters in year 2. Regression models using the instrumental variable (OCT and ophthalmoscopy combined) showed that ≥5.1 (95% CI: 3.3-11.4) ranibizumab injections were needed to maintain visual acuity from baseline to year 1 and ≥8.3 (95% CI: 5.3-18.8) injections were needed to maintain visual acuity from year 1 to year 2. To gain ≥15 letters, ≥7.9 (95% CI: 5.1-17.5) ranibizumab injections would be needed in year 1 and ≥16.1 (95% CI: 10.3-36.4) injections would be needed over 2 years.ConclusionsThese findings highlight the role that regular monitoring plays in guiding neovascular AMD therapy and they showed that the number of ranibizumab injections needed to maintain visual acuity is higher than that administered in AURA.

  11. Global motion perception is independent from contrast sensitivity for coherent motion direction discrimination and visual acuity in 4.5-year-old children

    PubMed Central

    Chakraborty, Arijit; Anstice, Nicola S.; Jacobs, Robert J.; Paudel, Nabin; LaGasse, Linda L.; Lester, Barry M.; Wouldes, Trecia A.; Harding, Jane E.; Thompson, Benjamin

    2015-01-01

    Global motion processing depends on a network of brain regions that includes extrastriate area V5 in the dorsal visual stream. For this reason, psychophysical measures of global motion perception have been used to provide a behavioural measure of dorsal stream function. This approach assumes that global motion is relatively independent of visual functions that arise earlier in the visual processing hierarchy such as contrast sensitivity and visual acuity. We tested this assumption by assessing the relationships between global motion perception, contrast sensitivity for coherent motion direction discrimination (henceforth referred to as contrast sensitivity) and habitual visual acuity in a large group of 4.5-year-old children (n = 117). The children were born at risk of abnormal neurodevelopment because of prenatal drug exposure or risk factors for neonatal hypoglycaemia. Motion coherence thresholds, a measure of global motion perception, were assessed using random dot kinematograms. The contrast of the stimuli was fixed at 100% and coherence was varied. Contrast sensitivity was measured using the same stimuli by fixing motion coherence at 100% and varying dot contrast. Stereoacuity was also measured. Motion coherence thresholds were not correlated with contrast sensitivity or visual acuity. However, lower (better) motion coherence thresholds were correlated with finer stereoacuity (rho=0.38, p=0.004). Contrast sensitivity and visual acuity were also correlated (rho= −0.26, p=0.004) with each other. These results indicate that global motion perception for high contrast stimuli is independent of contrast sensitivity and visual acuity and can be used to assess motion integration mechanisms in children. PMID:26318529

  12. Macular edema in Asian Indian premature infants with retinopathy of prematurity: Impact on visual acuity and refractive status after 1-year

    PubMed Central

    Vinekar, Anand; Mangalesh, Shwetha; Jayadev, Chaitra; Bauer, Noel; Munusamy, Sivakumar; Kemmanu, Vasudha; Kurian, Mathew; Mahendradas, Padmamalini; Avadhani, Kavitha; Shetty, Bhujang

    2015-01-01

    Purpose: To report the impact of transient, self-resolving, untreated “macular edema” detected on spectral domain optical coherence tomography in Asian Indian premature infants with retinopathy of prematurity (ROP) on visual acuity (VA) and refraction at 1-year of corrected age. Materials and Methods: Visual acuity and refraction of 11 infants with bilateral macular edema (Group A) was compared with gestational age-matched 16 infants with ROP without edema (Group B) and 17 preterms infants without ROP and without edema (Group C) at 3, 6, 9 and 12 months of corrected age using Teller Acuity Cards and cycloplegic retinoscopy. Sub-group analysis of the previously described pattern A and B macular edema was performed. Results: Visual acuity was lower in infants with macular edema compared with the other two control groups throughout the study period, but statistically significant only at 3 months. Visual improvement in these infants was highest between the 3rd and 6th month and plateaued by the end of the 1st year with acuity comparable to the other two groups. The edema cohort was more hyperopic compared to the other two groups between 3 and 12 months of age. Pattern A edema had worse VA compared to pattern B, although not statistically significant. Conclusion: Macular edema, although transient, caused reduced VA as early as 3 months of corrected age in Asian Indian premature infants weighing <2000 g at birth. The higher hyperopia in these infants is possibly due to visual disturbances caused at a critical time of fovealization. We hypothesize a recovery and feedback mechanism based on the principles of active emmetropization to explain our findings. PMID:26139806

  13. Visual Acuity after Cataract Surgery in Patients with Age-Related Macular Degeneration. Age-Related Eye Disease Study 2 Report No. 5

    PubMed Central

    Huynh, Nancy; Nicholson, Benjamin P.; Agrón, Elvira; Clemons, Traci E.; Bressler, Susan B.; Rosenfeld, Philip J.; Chew, Emily Y.

    2014-01-01

    Objective To evaluate visual acuity outcomes after cataract surgery in persons with varying severity of age-related macular degeneration (AMD). Design Cohort study. Participants A total of 1232 eyes of 793 participants who underwent cataract surgery during the Age-Related Eye Disease Study 2 (AREDS2), a prospective, multicenter, randomized controlled trial of nutritional supplements for treatment of AMD. Methods Preoperative and postoperative characteristics of participants who underwent cataract extraction during the 5 year trial were analyzed. Both clinical data and standardized red-reflex lens and fundus photographs were obtained at baseline and annually. Photographs were graded by a centralized reading center for cortical and posterior subcapsular lens opacities and for AMD severity. Cataract surgery was documented at annual study visits or by history during the 6 month telephone calls. Analyses were conducted using multivariate repeated-measures regression. Main Outcome Measures Change in best-corrected visual acuity (BCVA) after cataract surgery compared with preoperative BCVA. Results Adjusting for age at time of surgery, gender, interval between preoperative and postoperative visits, and type and severity of cataract, the mean changes in visual acuity were as follows: eyes with mild AMD (n=30) gained 11.2 letters (95% confidence interval (CI), 6.9-15.5), eyes with moderate AMD (n=346) gained 11.1 letters (95% CI, 9.1-13.2), eyes with severe AMD (n=462) gained 8.7 letters (95% CI, 6.7-10.7), eyes with non-central geographic atrophy (n=70) gained 8.9 letters (95% CI, 5.8-12.1), and eyes with advanced AMD (central geographic atrophy and/or neovascular) AMD (n=324) gained 6.8 letters (95% CI, 4.9-8.8). The visual acuity gain across all AMD severity groups was statistically significant from pre-operative state (P<0.0001). Conclusions Mean visual acuities improved significantly after cataract surgery across varying degrees of AMD severity. PMID:24613825

  14. Oil Reserve: Some Concerns Remain About SPR Drawdown and Distribution

    DTIC Science & Technology

    1990-11-01

    and to the ARCO ter- minal in Texas City , Texas. These terminals provide connections to two marine terminals and nine refineries in Texas. 0 Texoma...RCED-91-16 Oil Reserve: Some Concerns Remain Chater 2 DOE’s Egbleatis of Crient Drawdown Capabllity Appear Reamnable, but Tankeir MAmilability Col

  15. 18. A view looking southeast at the remains of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. A view looking southeast at the remains of the director's office, his reception room and a portion of the elevator lobby. These two rooms were equipped with their own air conditioners. - John T. Beasley Building, 632 Cherry Street (between Sixth & Seventh Streets), Terre Haute, Vigo County, IN

  16. 17. DETAIL OF THE REMAINS OF BLAST FURNACE No. 2 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. DETAIL OF THE REMAINS OF BLAST FURNACE No. 2 LOOKING EAST. THE BUSTLE PIPE IS VISIBLE ACROSS THE CENTER OF THE IMAGE. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  17. 15. NORTHERN VIEW OF THE REMAINS OF BLAST FURNACE No. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. NORTHERN VIEW OF THE REMAINS OF BLAST FURNACE No. 2 IN LOWER CENTER OF PHOTO AT THE BASE OF HOT BLAST STOVES. HOIST HOUSE No. 2 IS ON THE LEFT. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  18. 8. NORTHWEST VIEW OF REMAINS OF CAST HOUSE No. 2. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. NORTHWEST VIEW OF REMAINS OF CAST HOUSE No. 2. BLAST FURNACE No. 1 IS ON THE RIGHT, AND HOIST HOUSE No. 2 IS ON THE LEFT. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  19. 1. View from Roundhouse roof showing remains of gable (north) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. View from Roundhouse roof showing remains of gable (north) end and clerestory monitor of Machine Shop. - Central of Georgia Railway, Savannah Repair Shops & Terminal Facilities, Machine Shop, Bounded by West Broad, Jones, West Boundary & Hull Streets, Savannah, Chatham County, GA

  20. Ancient DNA in human bone remains from Pompeii archaeological site.

    PubMed

    Cipollaro, M; Di Bernardo, G; Galano, G; Galderisi, U; Guarino, F; Angelini, F; Cascino, A

    1998-06-29

    aDNA extraction and amplification procedures have been optimized for Pompeian human bone remains whose diagenesis has been determined by histological analysis. Single copy genes amplification (X and Y amelogenin loci and Y specific alphoid repeat sequences) have been performed and compared with anthropometric data on sexing.

  1. DETAIL VIEW OF FILTER PRESS REMAINS, BOILER, SECONDARY ORE BIN, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF FILTER PRESS REMAINS, BOILER, SECONDARY ORE BIN, TRAM TRESTLE AND WATER TANK, LOOKING NORTHWEST. HIS VIEW IS TAKEN FROM THE THIRD LEVEL OF THE MILL, NEARBY THE BLACKSMITH'S FORGE. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  2. Aftermath. The remains of the southwest end of the bridge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Aftermath. The remains of the southwest end of the bridge lie next to the southwest pier. View is south-southeast from confluence of Trinity and South Fork Trinity Rivers - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

  3. REAR DETAIL OF RIGHT ENGINE AND WING. THRUST REVERSER REMAINS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    REAR DETAIL OF RIGHT ENGINE AND WING. THRUST REVERSER REMAINS OPEN. MECHANICS JONI BAINE (R) AND BILL THEODORE(L) OPEN FLAP CARRIAGE ACCESS WITH AN IMPACT GUN. THEY WILL CHECK TRANSMISSION FLUID AND OIL THE JACK SCREW. AT FAR LEFT UTILITY MECHANICS BEGIN BODY POLISHING. - Greater Buffalo International Airport, Maintenance Hangar, Buffalo, Erie County, NY

  4. Remaining True to the Vision: Promoting Research in FCS

    ERIC Educational Resources Information Center

    Blackwell, Ann P.; Burgess, Anne M.

    2006-01-01

    There is an ongoing need for family and consumer sciences professionals to generate new knowledge through research and then share findings with diverse groups. Specific Action Steps describe methods to incorporate research into university curricula to promote this role. The ultimate goal is to inspire new professionals to remain true to the…

  5. Collegial Climate and Novice Teachers' Intent to Remain Teaching

    ERIC Educational Resources Information Center

    Pogodzinski, Ben; Youngs, Peter; Frank, Kenneth A.

    2013-01-01

    Using survey data from novice teachers across 99 schools, we estimated multilevel regressions to identify the association between novices' intent to remain teaching within their schools and their perceptions of the collegial climate. The results suggest that novice teachers who perceive a more positive collegial climate marked by higher degrees…

  6. Administrative Climate and Novices' Intent to Remain Teaching

    ERIC Educational Resources Information Center

    Pogodzinski, Ben; Youngs, Peter; Frank, Kenneth A.; Belman, Dale

    2012-01-01

    Using survey data from novice teachers at the elementary and middle school level across 11 districts, multilevel logistic regressions were estimated to examine the association between novices' perceptions of the administrative climate and their desire to remain teaching within their schools. We find that the probability that a novice teacher…

  7. Remains of abutments for Bridge No. 1575 at MD Rt. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Remains of abutments for Bridge No. 1575 at MD Rt. 51 in Spring Gap, Maryland, looking northeast. (Compare with HAER MD-115 photos taken 1988). - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  8. 6. DETAIL OF NORTH FRONT, SHOWING REMAINING WALL OF ORIGINAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. DETAIL OF NORTH FRONT, SHOWING REMAINING WALL OF ORIGINAL BUILDING AND UTILITY BRIDGE TO BUILDING ACROSS NINTH STREET HABS No. IA-160-AR. VIEW TO SOUTH. - Commercial & Industrial Buildings, Klauer Manufacturing Company Factory, 301 Ninth Street, Dubuque, Dubuque County, IA

  9. 22. Detail of remnants of winch and motor on remains ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Detail of remnants of winch and motor on remains of machinery house platform east of drawspan; note cables (still connected to drawspan) coming off the winding drum; view to north. - Summer Street Bridge, Spanning Reserved Channel, Boston, Suffolk County, MA

  10. Robotics to Enable Older Adults to Remain Living at Home

    PubMed Central

    Pearce, Alan J.; Adair, Brooke; Ozanne, Elizabeth; Said, Catherine; Santamaria, Nick; Morris, Meg E.

    2012-01-01

    Given the rapidly ageing population, interest is growing in robots to enable older people to remain living at home. We conducted a systematic review and critical evaluation of the scientific literature, from 1990 to the present, on the use of robots in aged care. The key research questions were as follows: (1) what is the range of robotic devices available to enable older people to remain mobile, independent, and safe? and, (2) what is the evidence demonstrating that robotic devices are effective in enabling independent living in community dwelling older people? Following database searches for relevant literature an initial yield of 161 articles was obtained. Titles and abstracts of articles were then reviewed by 2 independent people to determine suitability for inclusion. Forty-two articles met the criteria for question 1. Of these, 4 articles met the criteria for question 2. Results showed that robotics is currently available to assist older healthy people and people with disabilities to remain independent and to monitor their safety and social connectedness. Most studies were conducted in laboratories and hospital clinics. Currently limited evidence demonstrates that robots can be used to enable people to remain living at home, although this is an emerging smart technology that is rapidly evolving. PMID:23304507

  11. 3. GENERAL VIEW OF REMAINS OF 40" BLOOMING MILL; THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. GENERAL VIEW OF REMAINS OF 40" BLOOMING MILL; THE ENGINE ROOM CONTAINING THE MESTA-CORLISS STEAM ENGINE, IS LOCATED AT THE FAR END OF THE MILL AS SEEN TO THE FAR RIGHT (THE BUILDING WITH THE SHED ROOF). - Republic Iron & Steel Company, Youngstown Works, Blooming Mill & Blooming Mill Engines, North of Poland Avenue, Youngstown, Mahoning County, OH

  12. 4. An interior view of remaining duct system and grain ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. An interior view of remaining duct system and grain separating equipment is situated within the 'Landmark' (1940) in the section above the silo portion of the structure. - Quaker Oats Cereal Factory, Southeast corner of Broadway & Mill Streets, Akron, Summit County, OH

  13. Interior of control house showing remains of controller. Moving the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior of control house showing remains of controller. Moving the handle rotated the vertical shaft and porcelain cams to engage various electrical switches and activate the lift mechanism. All electrical components have been removed. - Potomac Edison Company, Chesapeake & Ohio Canal Bridge, Spanning C & O Canal South of U.S. 11, Williamsport, Washington County, MD

  14. 8. View of remains of ash bin at Armory Street ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. View of remains of ash bin at Armory Street Pump House. Ashes would be removed via a dump truck driven under the hopper above the garage door. - Lake Whitney Water Filtration Plant, Armory Street Pumphouse, North side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  15. As Year Ends, Questions Remain for New Orleans

    ERIC Educational Resources Information Center

    Maxwell, Lesli A.

    2008-01-01

    In rebuilding public schooling in New Orleans after Hurricane Katrina, education reformers have managed to hire energetic teachers, break ground on a few new school buildings, raise public confidence, and show progress on test scores. But fundamental questions remain as the 2007-08 academic year draws to a close, including how the city's…

  16. 1. VIEW OF CRUSHING PLANT (FEATURE 19). THE REMAINS OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW OF CRUSHING PLANT (FEATURE 19). THE REMAINS OF THE FINE ORE MILL (FEATURE 20) ARE IN THE BACKGROUND ON LEFT. CONCRETE RESERVOIR (FEATURE 22) IS SHOWN AT THE RIGHT EDGE OF PHOTOGRAPH FACING SOUTHWEST. - Copper Canyon Camp of the International Smelting & Refining Company, Crushing Plant, Copper Canyon, Battle Mountain, Lander County, NV

  17. 19. REMAINS OF FLYWHEEL OF No. 1 PRESS PUMPING ENGINE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. REMAINS OF FLYWHEEL OF No. 1 PRESS PUMPING ENGINE. GEARS ON EITHER SIDE OF THE FLYWHEEL WERE TURNED INTERMEDIATE GEARS WHICH POWERED THE PUMPS. - U.S. Steel Homestead Works, Press Shop No. 1, Along Monongahela River, Homestead, Allegheny County, PA

  18. 6. Remains Beneath Collapsed Engine House Roof, Showing Foundation Timbers ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Remains Beneath Collapsed Engine House Roof, Showing Foundation Timbers and Automobile Engine Connected to Pulley Wheel, Looking Southwest - David Renfrew Oil Rig, East side of Connoquenessing Creek, 0.4 mile North of confluence with Thorn Creek, Renfrew, Butler County, PA

  19. 5. View of remaining rock ledge from construction of passage ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. View of remaining rock ledge from construction of passage to enter mill (Riverdale Cotton Mill was built into the side of a hill). Partially subterranean area was popular with employees trying to escape the heat of the mill, now an unofficial smoking area. - Riverdale Cotton Mill, Corner of Middle & Lower Streets, Valley, Chambers County, AL

  20. 15. CYLINDRICAL FISH SCALER Remnants of the wire screen remain, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. CYLINDRICAL FISH SCALER Remnants of the wire screen remain, through which the fish tumbled as the cylinder revolved. Note geared ring around cylinder, and the small drive shaft by which it was driven. - Hovden Cannery, 886 Cannery Row, Monterey, Monterey County, CA

  1. Neanderthal infant and adult infracranial remains from Marillac (Charente, France).

    PubMed

    Dolores Garralda, María; Maureille, Bruno; Vandermeersch, Bernard

    2014-09-01

    At the site of Marillac, near the Ligonne River in Marillac-le-Franc (Charente, France), a remarkable stratigraphic sequence has yielded a wealth of archaeological information, palaeoenvironmental data, as well as faunal and human remains. Marillac must have been a sinkhole used by Neanderthal groups as a hunting camp during MIS 4 (TL date 57,600 ± 4,600BP), where Quina Mousterian lithics and fragmented bones of reindeer predominate. This article describes three infracranial skeleton fragments. Two of them are from adults and consist of the incomplete shafts of a right radius (Marillac 24) and a left fibula (Marillac 26). The third fragment is the diaphysis of the right femur of an immature individual (Marillac 25), the size and shape of which resembles those from Teshik-Tash and could be assigned to a child of a similar age. The three fossils have been compared with the remains of other Neanderthals or anatomically Modern Humans (AMH). Furthermore, the comparison of the infantile femora, Marillac 25 and Teshik-Tash, with the remains of several European children from the early Middle Ages clearly demonstrates the robustness and rounded shape of both Neanderthal diaphyses. Evidence of peri-mortem manipulations have been identified on all three bones, with spiral fractures, percussion pits and, in the case of the radius and femur, unquestionable cutmarks made with flint implements, probably during defleshing. Traces of periostosis appear on the fibula fragment and on the immature femoral diaphysis, although their aetiology remains unknown.

  2. 18F-FDG PET in the Evaluation of Acuity of Deep Vein Thrombosis

    PubMed Central

    Rondina, Matthew T.; Lam, Uyen T.; Pendleton, Robert C.; Kraiss, Larry W.; Wanner, Nathan; Zimmerman, Guy A.; Hoffman, John M.; Hanrahan, Christopher; Boucher, Kenneth; Christian, Paul E.; Butterfield, Regan I.; Morton, Kathryn A.

    2013-01-01

    Purpose 18F-FDG PET has been used for vascular disease, but its role in deep vein thrombosis (DVT) remains prospectively unexplored. Patients and Methods Whole-body 18F-FDG PET/CT scans were performed in patients 1 to 10 weeks after onset of symptomatic DVT (n = 12) and in control subjects without DVT (n = 24). The metabolic activity (SUVmax) of thrombosed and contralateral nonthrombosed vein segments was determined. The sensitivity and specificity of 18F-FDG PET/CT for the diagnosis of DVT were determined by receiver operating characteristic curve analyses. In 2 patients with DVT, changes in the metabolic activity of thrombosed vein segments in serial 18F-FDG PET scans. Results The metabolic activity in thrombosed veins [SUVmax, 2.41 (0.75)] was visually appreciable and significantly higher than in nonthrombosed veins in either the contralateral extremity of patients with DVT [SUVmax, 1.09 (0.25), P = 0.007] or control subjects [1.21 (0.22), P < 001]. The area under the receiver operating characteristic curve for SUVmax was 0.9773 (P < 001), indicating excellent accuracy. An SUVmax threshold of greater than 1.645 was 87.5% sensitive and 100% specific for DVT. Metabolic activity in thrombosed veins correlated significantly with time from DVT symptom onset (decrease in SUVmax of 0.02/d, P < 0.05). Best-fit-line analyses suggested that approximately 84 to 91 days after acute DVT, the maximum metabolic activity of thrombosed veins would return to normal levels. Conclusions 18F-FDG PET/CT is accurate for detecting acute symptomatic, proximal DVT. Metabolic activity in thrombosed veins decreases with time, suggesting that 18F-FDG PET may be helpful in assessing the age of the clot. PMID:23154470

  3. Diagnosis of aortic dextroposition on human skeletal remains.

    PubMed

    Charlier, Philippe; Costea, Georgică; Huynh-Charlier, Isabelle; Brun, Luc; de la Grandmaison, Geoffroy Lorin

    2012-03-01

    The fine macroscopic observation of a young adult female skeleton recovered from a Roman graveyard in Romania revealed distinctive flattening of the vertebra related to a right-sided aorta. Associated bone anomalies may be related to a Kartagener syndrome. This case highlights the fact that visceral anomalies may be diagnosed even on skeletal remains. Such lesions could be useful for osteo-archaeologists, of course, but also for forensic anthropologist investigators dealing with skeletonized remains (for example during the identification process of a dead body, through comparison with known medical data for missing people). More, hypotheses about cause and/or manner of death may be given, and a possibility of genetic confirmation exists.

  4. Mineral remains of early life on Earth? On Mars?

    USGS Publications Warehouse

    Iberall, Robbins E.; Iberall, A.S.

    1991-01-01

    The oldest sedimentary rocks on Earth, the 3.8-Ga Isua Iron-Formation in southwestern Greenland, are metamorphosed past the point where organic-walled fossils would remain. Acid residues and thin sections of these rocks reveal ferric microstructures that have filamentous, hollow rod, and spherical shapes not characteristic of crystalline minerals. Instead, they resemble ferric-coated remains of bacteria. Because there are no earlier sedimentary rocks to study on Earth, it may be necessary to expand the search elsewhere in the solar system for clues to any biotic precursors or other types of early life. A study of morphologies of iron oxide minerals collected in the southern highlands during a Mars sample return mission may therefore help to fill in important gaps in the history of Earth's earliest biosphere. -from Authors

  5. Radiocarbon analysis of human remains: a review of forensic applications.

    PubMed

    Ubelaker, Douglas H

    2014-11-01

    Radiocarbon analysis of organic materials, with the comparison of values with those of the post-1950 modern bomb curve, has proven useful in forensic science to help evaluate the antiquity of evidence. Applications are particularly helpful in the study of human remains, especially with those displaying advanced decomposition of soft tissues. Radiocarbon analysis can reveal if the remains relate to the modern, post-1950 era and if so, also provide information needed to evaluate the death and birth date. Sample selection and interpretation of results must be guided by knowledge of the formation and remodeling of different human tissues, as well as contextual information and the approximate age at death of the individual represented. Dental enamel does not remodel and thus captures dietary radiocarbon values at the time of juvenile formation. Most other human tissues do remodel but at differing rates and therefore collectively offer key information relative to the estimation of the death date.

  6. Dental DNA fingerprinting in identification of human remains.

    PubMed

    Girish, Kl; Rahman, Farzan S; Tippu, Shoaib R

    2010-07-01

    The recent advances in molecular biology have revolutionized all aspects of dentistry. DNA, the language of life yields information beyond our imagination, both in health or disease. DNA fingerprinting is a tool used to unravel all the mysteries associated with the oral cavity and its manifestations during diseased conditions. It is being increasingly used in analyzing various scenarios related to forensic science. The technical advances in molecular biology have propelled the analysis of the DNA into routine usage in crime laboratories for rapid and early diagnosis. DNA is an excellent means for identification of unidentified human remains. As dental pulp is surrounded by dentin and enamel, which forms dental armor, it offers the best source of DNA for reliable genetic type in forensic science. This paper summarizes the recent literature on use of this technique in identification of unidentified human remains.

  7. The impact of downsizing on remaining workers' sickness absence.

    PubMed

    Østhus, Ståle; Mastekaasa, Arne

    2010-10-01

    It is generally assumed that organizational downsizing has considerable negative consequences, not only for workers that are laid off, but also for those who remain employed. The empirical evidence with regard to effects on sickness absence is, however, inconsistent. This study employs register data covering a major part of the total workforce in Norway over the period 2000-2003. The number of sickness absence episodes and the number of sickness absence days are analysed by means of Poisson regression. To control for both observed and unobserved stable individual characteristics, we use conditional (fixed effects) estimation. The analyses provide some weak indications that downsizing may lead to slightly less sickness absence, but the overall impression is that downsizing has few if any effects on the sickness absence of the remaining employees.

  8. Remaining useful life prediction based on known usage data

    NASA Astrophysics Data System (ADS)

    Kiddy, Jason S.

    2003-08-01

    Systems Planning and Analysis, Inc. (SPA) has developed a novel statistical approach to estimating the remaining useful life of aircraft components based on known usage monitoring data. The analysis technique is known as the Remaining Useful Life Estimation (RULE) methodology. The basic premise of RULE is to determine conservative predictions for the component loads and fatigue life values from Monte Carlo simulations based on a desired component reliability. Then, as the aircraft's usage is monitored, the component life can be calculated with a known reliability based on the conservative predictions generated by the Monte Carlo simulation. The RULE methodology, which has been successfully tested on small-scale analytical problems, is ideally suited to be integrated into both rotorcraft and fixed-wing aircraft. Furthermore, modifications to the technology may prove to be applicable to wide variety of health and prognostic problems.

  9. Late Pleistocene human remains from Wezmeh Cave, western Iran.

    PubMed

    Trinkaus, Erik; Biglari, Fereidoun; Mashkour, Marjan; Monchot, Hervé; Reyss, Jean-Louis; Rougier, Hélène; Heydari, Saman; Abdi, Kamyar

    2008-04-01

    Paleontological analysis of remains from Wezmeh Cave in western Iran have yielded a Holocene Chalcolithic archeological assemblage, a rich Late Pleistocene carnivore faunal assemblage, and an isolated unerupted human maxillary premolar (P(3) or possibly P(4)). Species representation and U-series dating of faunal teeth place the carnivore assemblage during oxygen isotope stages (OIS) 3 and 2, and noninvasive gamma spectrometry dating of the human premolar places it at least as old as early OIS 2. The human premolar crown morphology is not diagnostic of late archaic versus early modern human affinities, but its buccolingual diameter places it at the upper limits of Late Pleistocene human P(3) and P(4) dimensions and separate from a terminal Pleistocene regional sample. Wezmeh Cave therefore provides additional Paleolithic human remains from the Zagros Mountains and further documents Late Pleistocene human association with otherwise carnivore-dominated cave assemblages.

  10. Mandibular remains support taxonomic validity of Australopithecus sediba.

    PubMed

    de Ruiter, Darryl J; DeWitt, Thomas J; Carlson, Keely B; Brophy, Juliet K; Schroeder, Lauren; Ackermann, Rebecca R; Churchill, Steven E; Berger, Lee R

    2013-04-12

    Since the announcement of the species Australopithecus sediba, questions have been raised over whether the Malapa fossils represent a valid taxon or whether inadequate allowance was made for intraspecific variation, in particular with reference to the temporally and geographically proximate species Au. africanus. The morphology of mandibular remains of Au. sediba, including newly recovered material discussed here, shows that it is not merely a late-surviving morph of Au. africanus. Rather-as is seen elsewhere in the cranium, dentition, and postcranial skeleton-these mandibular remains share similarities with other australopiths but can be differentiated from the hypodigm of Au. africanus in both size and shape as well as in their ontogenetic growth trajectory.

  11. Remaining Pain in Early Rheumatoid Arthritis Patients Treated With Methotrexate

    PubMed Central

    Altawil, Reem; Saevarsdottir, Saedis; Wedrén, Sara; Alfredsson, Lars; Klareskog, Lars

    2016-01-01

    Objective To investigate the frequency of remaining pain in early rheumatoid arthritis (RA) after 3 months of treatment with methotrexate as the only disease modifying antirheumatic drug, with a special focus on patients with a good clinical response. Methods The study base was cases reported to a population‐based early RA cohort who had followup data from the Swedish Rheumatology Quality Register (n = 1,241). The Disease Activity Score in 28 joints European League Against Rheumatism (EULAR) response criteria were used to evaluate clinical response to treatment as good, moderate, and no response. The primary end point was remaining pain at the 3‐months followup visit, defined as pain >20 mm on a 100‐mm visual analog scale (VAS). Results Remaining pain in spite of a EULAR good response at followup was associated with higher baseline disability, using the Health Assessment Questionnaire (adjusted odds ratio [OR] 2.2 [95% confidence interval (95% CI) 1.4–3.4] per unit increase), and less baseline inflammation, using the erythrocyte sedimentation rate (adjusted OR 0.81 [95% CI 0.70–0.93] per 10‐mm increase). Similar associations were detected for remaining pain at followup in spite of low inflammatory activity, defined as a C‐reactive protein level <10. Increase in VAS pain during the treatment period was observed in 19% of the whole cohort, with frequencies in the EULAR response groups of 9% (good response), 15% (moderate response), and 45% (no response). Conclusion These results are in line with the hypothesis that a subgroup of early RA patients exhibits pain that is not inflammatory mediated, where alternative treatment strategies to traditional antiinflammatory medications need to be considered. PMID:26784398

  12. USING CONDITION MONITORING TO PREDICT REMAINING LIFE OF ELECTRIC CABLES.

    SciTech Connect

    LOFARO,R.; SOO,P.; VILLARAN,M.; GROVE,E.

    2001-03-29

    Electric cables are passive components used extensively throughout nuclear power stations to perform numerous safety and non-safety functions. It is known that the polymers commonly used to insulate the conductors on these cables can degrade with time; the rate of degradation being dependent on the severity of the conditions in which the cables operate. Cables do not receive routine maintenance and, since it can be very costly, they are not replaced on a regular basis. Therefore, to ensure their continued functional performance, it would be beneficial if condition monitoring techniques could be used to estimate the remaining useful life of these components. A great deal of research has been performed on various condition monitoring techniques for use on electric cables. In a research program sponsored by the U.S. Nuclear Regulatory Commission, several promising techniques were evaluated and found to provide trendable information on the condition of low-voltage electric cables. These techniques may be useful for predicting remaining life if well defined limiting values for the aging properties being measured can be determined. However, each technique has advantages and limitations that must be addressed in order to use it effectively, and the necessary limiting values are not always easy to obtain. This paper discusses how condition monitoring measurements can be used to predict the remaining useful life of electric cables. The attributes of an appropriate condition monitoring technique are presented, and the process to be used in estimating the remaining useful life of a cable is discussed along with the difficulties that must be addressed.

  13. Hominid mandibular remains from Sangiran: 1952-1986 collection.

    PubMed

    Kaifu, Yousuke; Aziz, Fachroel; Baba, Hisao

    2005-11-01

    Eight hominid mandibular and associated dental remains discovered between 1952-1986 from the Early Pleistocene deposits of Sangiran, Central Java, are described. Although the specimens are surface finds, their original stratigraphic positions can be reasonably inferred on the basis of coincidental sources of information. These specimens significantly increase the dento-gnathic sample available for intensive morphological investigation of the earliest Javanese hominids [Kaifu et al., 2005].

  14. Skeletal preservation of children's remains in the archaeological record.

    PubMed

    Manifold, B M

    2015-12-01

    Taphonomy is an important consideration in the reconstruction of past environments and events. Taphonomic alterations and processes are commonly encountered on human skeletal remains in both archaeological and forensic contexts. It is these processes that can alter the appearance of bone after death and the properties of the bones influence their reaction to these processes thus leading to differential preservation within a skeletal sample, none more so than the remains of children. This study investigates the skeletal preservation of 790 child and adolescent skeletons from six contrasting early and late medieval cemeteries from Britain in an attempt to assess whether geographical location and geology had an effect on the overall preservation of the skeletons. Skeletons were examined from six cemeteries, namely; Auldhame in Scotland, Edix Hill and Great Chesterford from Cambridgeshire; St Oswald's Priory from Gloucester and Wharram Percy from Yorkshire, and finally, the site of Llandough in Wales. The state of preservation was assessed using the anatomical preservation index (AP1), qualitative bone index (QBI) and the bone representation index (BRI). Also the presence of natural and artificial taphonomic processes was recorded for each skeleton. The results show a specific pattern of preservation and representation for non-adult remains across all sites with some differences in the states of preservation from different geographical locations and geological influences. Children under two years of age were found to be less affected by taphonomic processes than their older counterparts.

  15. Microsatellites identify depredated waterfowl remains from glaucous gull stomachs

    USGS Publications Warehouse

    Scribner, K.T.; Bowman, Timothy D.

    1998-01-01

    Prey remains can provide valuable sources of information regarding causes of predation and the species composition of a predator's diet. Unfortunately, the highly degraded state of many prey samples from gastrointestinal tracts often precludes unambiguous identification. We describe a procedure by which PCR amplification of taxonomically informative microsatellite loci were used to identify species of waterfowl predated by glaucous gulls (Larus hyperboreus). We found that one microsatellite locus unambiguously distinguished between species of the subfamily Anserinae (whistling ducks, geese and swans) and those of the subfamily Anatidae (all other ducks). An additional locus distinguished the remains of all geese and swan species known to nest on the Yukon-Kuskokwim delta in western Alaska. The study focused on two waterfowl species which have experienced precipitous declines in population numbers: emperor geese (Chen canagica) and spectacled eiders (Somateria fischeri). No evidence of predation on spectacled eiders was observed. Twenty-six percent of all glaucous gull stomachs examined contained the remains of juvenile emperor geese.

  16. Genetic analysis of modern and historical burned human remains.

    PubMed

    von Wurmb-Schwark, Nicole; Ringleb, Arne; Gebühr, Michael; Simeoni, Eva

    2005-03-01

    Burning of corpses is a well-known funeral procedure that has been performed for a long time in many cultures. Nowadays more and more corpses are burned in crematories and buried in urns, often for practical and financial reasons. In some scientific, criminal or civil cases even after cremation there is the need of genetic investigations for identification or paternity testing. Furthermore, burned remains are the only remains left in North Europe from 1200 BC to 500 AD. This makes genetic investigation of those materials interesting for anthropological reasons. We present on one hand a systematic investigation of 10 corpses before and after the cremation and on the other hand the analysis of seven historical remains representing the bronze age. We chose the ground bone powder and the less destroyed bone parts respectively and employed a slightly modified commercially available DNA extraction method. The presence of human nuclear and mitochondrial DNA was tested by a simple but highly sensitive Duplex-PCR. DNA quantification was done using real time PCR, and genetic typing was tried out using the AmpFISTR Identifiler Multiplex Kit, followed by an automatic analysis on an AbiPrism310.

  17. Prognostic modelling options for remaining useful life estimation by industry

    NASA Astrophysics Data System (ADS)

    Sikorska, J. Z.; Hodkiewicz, M.; Ma, L.

    2011-07-01

    Over recent years a significant amount of research has been undertaken to develop prognostic models that can be used to predict the remaining useful life of engineering assets. Implementations by industry have only had limited success. By design, models are subject to specific assumptions and approximations, some of which are mathematical, while others relate to practical implementation issues such as the amount of data required to validate and verify a proposed model. Therefore, appropriate model selection for successful practical implementation requires not only a mathematical understanding of each model type, but also an appreciation of how a particular business intends to utilise a model and its outputs. This paper discusses business issues that need to be considered when selecting an appropriate modelling approach for trial. It also presents classification tables and process flow diagrams to assist industry and research personnel select appropriate prognostic models for predicting the remaining useful life of engineering assets within their specific business environment. The paper then explores the strengths and weaknesses of the main prognostics model classes to establish what makes them better suited to certain applications than to others and summarises how each have been applied to engineering prognostics. Consequently, this paper should provide a starting point for young researchers first considering options for remaining useful life prediction. The models described in this paper are Knowledge-based (expert and fuzzy), Life expectancy (stochastic and statistical), Artificial Neural Networks, and Physical models.

  18. Hospital nurses' intentions to remain: exploring a northern context.

    PubMed

    Tallman, Rick; Bruning, Nealia S

    2005-01-01

    Retaining nurses is of significant concern to all hospitals but even more of a concern to northern and rural hospital managers. This study provides insights into factors related to nurses' intentions to remain. A sample of 122 nurses from 13 northern hospitals in Western Canada participated in the study. The nurses completed questionnaires and participated in structured interviews. A model was proposed which suggested that work experiences (job and decision latitude, feedback, perceptions of how viewed and treated by others, fairness of policies, and safety of the job environment) would be related to job satisfaction and then affective commitment. Age and tenure, and ties to the community were proposed as predictors of continuance commitment. Both affective and continuance commitments were expected to be related to intention to remain in the hospital. The model was partially supported by regression analyses. Work experiences predicted job satisfaction and affective commitment. Affective commitment, continuance commitment, and ties to the community are related to nurses' intentions to remain. Supplemental analyses indicated that the strongest relationships were found for management's views and treatment of nurses, knowledge and ability utilization, safe environment, and fairness of organizational policies.

  19. The interactive effect of the degradation of cotton clothing and decomposition fluid production associated with decaying remains.

    PubMed

    Ueland, Maiken; Nizio, Katie D; Forbes, Shari L; Stuart, Barbara H

    2015-10-01

    Textiles are a commonly encountered source of evidence in forensic cases. In the past, most research has been focused on how textiles affect the decomposition process while little attention has been paid to how the decomposition products interact with the textiles. While some studies have shown that the presence of remains will have an effect on the degradation of clothing associated with a decaying body, very little work has been carried out on the specific mechanisms that prevent or delay textile degradation when in contact with decomposing remains. In order to investigate the effect of decomposition fluid on textile degradation, three clothed domestic pig (Sus scrofa domesticus) carcasses were placed on a soil surface, textile specimens were collected over a period of a year and were then analysed using ATR-FTIR spectroscopy and GC-MS. Multivariate statistical analysis was used to analyse the data. Cotton specimens not associated with remains degraded markedly, whereas the samples exposed to decomposition fluids remained relatively intact over the same time frame. An investigation of the decomposition by-products found that the protein-related bands remained stable and unchanged throughout the experiment. Lipid components, on the other hand, demonstrated a significant change; this was confirmed with the use of both ATR-FTIR spectroscopy and GC-MS. Through an advanced statistical approach, information about the decomposition by-products and their characteristics was obtained. There is potential that the lipid profile in a textile specimen could be a valuable tool used in the examination of clothing located at a crime scene.

  20. The Potential Importance of Detection of Neovascular Age-Related Macular Degeneration When Visual Acuity Is Relatively Good.

    PubMed

    Ho, Allen C; Albini, Thomas A; Brown, David M; Boyer, David S; Regillo, Carl D; Heier, Jeffrey S

    2017-03-01

    The advent of anti-vascular endothelial growth factor treatment has changed the prognosis for patients with neovascular age-related macular degeneration (nvAMD). The ability to stabilize or improve vision with these treatments is a major step in enabling patients to continue to function at the highest possible level. Many studies have demonstrated that the better the visual acuity (VA) is at the time of treatment initiation, the higher the likelihood that VA will be better during at least the following 2 years; as such, detection of nvAMD when VA is relatively good is important. Data on the VA of patients with intermediate AMD and VA at the time of nvAMD diagnosis suggest that patients are typically losing an average of 3 to 5 lines of vision and possibly more between the time that intermediate AMD progresses to nvAMD and the diagnosis of nvAMD is made. The average patient may have nvAMD for 6 to 12 months before diagnosis and treatment initiation. Current efforts in management of nvAMD are primarily aimed at optimizing anti-vascular endothelial growth factor treatments that have the potential to improve VA outcomes by a magnitude of letters. Additional tools or other efforts to identify patients with nvAMD before substantial vision loss has occurred may reduce the amount of visual loss sustained with anti-vascular endothelial growth factor therapy, and have the potential to improve VA outcomes substantially.