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Relationship Between Foveal Cone Structure and Visual Acuity Measured With Adaptive Optics Scanning Laser Ophthalmoscopy in Retinal Degeneration.
PurposeTo evaluate foveal function in patients with inherited retinal degenerations (IRD) by measuring visual acuity (VA) after correction of higher-order aberrations.MethodsAdaptive optics scanning laser ophthalmoscopy (AOSLO) was used to image cones in 4 healthy subjects and 15 patients with IRD. The 840-nm scanning laser delivered an "E" optotype to measure AOSLO-mediated VA (AOSLO-VA). Cone spacing was measured at the preferred retinal locus by two independent graders and the percentage of cones below the average density of 47 age-similar healthy subjects was computed. Cone spacing was correlated with best-corrected VA measured with the Early Treatment of Diabetic Retinopathy Study protocol (ETDRS-VA), AOSLO-VA, and foveal sensitivity.ResultsETDRS-VA significantly correlated with AOSLO-VA (Ï = 0.79, 95% confidence interval [CI] 0.5-0.9). Cone spacing correlated with AOSLO-VA (Ï = 0.54, 95% CI 0.02-0.7), and negatively correlated with ETDRS letters read (Ï = -0.64, 95% CI -0.8 to -0.2). AOSLO-VA remained â„20/20 until cones decreased to 40.2% (CI 31.1-45.5) below normal. Similarly, ETDRS-VA remained â„20/20 until cones were 42.0% (95% CI 36.5-46.1) below normal. Cone spacing z scores negatively correlated with foveal sensitivity (Ï = -0.79, 95% CI -0.9 to -0.4) and foveal sensitivity was â„35 dB until cones were 43.1% (95% CI 39.3-46.6) below average.ConclusionsVA and foveal cone spacing were weakly correlated until cones were reduced by 40% to 43% below normal. The relationship suggests that VA is an insensitive measure of foveal cone survival; cone spacing may be a more sensitive measure of cone loss
Protocols for calibrating multibeam sonar
Author Posting. © Acoustical Society of America, 2005. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 117 (2005): 2013-2027, doi:10.1121/1.1869073.Development of protocols for calibrating multibeam sonar by means of the standard-target method is documented. Particular systems used in the development work included three that provide the water-column signals, namely the SIMRAD SM2000/90- and 200-kHz sonars and RESON SeaBat 8101 sonar, with operating frequency of 240 kHz. Two facilities were instrumented specifically for the work: a sea well at the Woods Hole Oceanographic Institution and a large, indoor freshwater tank at the University of New Hampshire. Methods for measuring the transfer characteristics of each sonar, with transducers attached, are described and illustrated with measurement results. The principal results, however, are the protocols themselves. These are elaborated for positioning the target, choosing the receiver gain function, quantifying the system stability, mapping the directionality in the plane of the receiving array and in the plane normal to the central axis, measuring the directionality of individual beams, and measuring the nearfield response. General preparations for calibrating multibeam sonars and a method for measuring the receiver response electronically are outlined. Advantages of multibeam sonar calibration and outstanding problems, such as that of validation of the performance of multibeam sonars as configured for use, are mentioned.Support by the National Science Foundation through Award
No. OCE-0002664, NOAA through Grant No.
NA97OG0241, and the Cooperative Institute for Climate and
Ocean Research (CICOR) through NOAA Contract No.
NA17RJ1223 is acknowledged
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Cone Spacing Correlates With Retinal Thickness and Microperimetry in Patients With Inherited Retinal Degenerations.
PurposeTo determine whether high-resolution retinal imaging measures of macular structure correlate with visual function over 36 months in retinal degeneration (RD) patients and normal subjects.MethodsTwenty-six eyes of 16 RD patients and 16 eyes of 8 normal subjects were studied at baseline; 15 eyes (14 RD) and 11 eyes (6 normal) were studied 36 months later. Adaptive Optics Scanning Laser Ophthalmoscopy (AOSLO) was used to identify regions of interest (ROIs) with unambiguous cones at baseline to measure cone spacing. AOSLO images were aligned with spectral-domain optical coherence tomography (SD-OCT) and fundus-guided microperimetry results to correlate structure and function at the ROIs. SD-OCT images were segmented to measure inner segment (IS) and outer segment (OS) thickness. Correlations between cone spacing, IS and OS thickness and sensitivity were assessed using Spearman correlation coefficient Ï with bootstrap analyses clustered by person.ResultsCone spacing (Ï = 0.57, P < 0.001) and macular sensitivity (Ï = 0.19, P = 0.14) were significantly correlated with eccentricity in patients. Controlling for eccentricity, cone spacing Z-scores were inversely correlated with IS (Ï = -0.29, P = 0.002) and OS thickness (Ï = -0.39, P < 0.001) in RD patients only, and with sensitivity in normal subjects (Ï = -0.22, P < 0.001) and RD patients (Ï = -0.38, P < 0.001). After 36 months, cone spacing increased (P < 0.001) and macular sensitivity decreased (P = 0.007) compared to baseline in RD patients.ConclusionsCone spacing increased and macular sensitivity declined significantly in RD patients over 36 months. High resolution images of cone structure correlated with retinal sensitivity, and may be appropriate outcome measures for clinical trials in RD
Saving Lives and Dollars Through Comprehensive Preventive Health Care
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68280/2/10_1111_j_1741-6248_1993_00163_x.pd
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What Causes Social Marketing Programs to Fail? A Qualitative Study
This paper addresses the key factors that cause social marketing programs to fail. It argues that understanding these failures offers greater insight to researchers and practitioners than publications solely focused on successes. As the majority of practitioner-oriented social marketing research focuses on how to develop a successful program, we identify a tendency to ignore failed programs. We suggest that both researchers and practitioners can arguably learn more useful lessons from failures rather than successes. Thus, this paper contributes to social marketing literature by exploring the key causes of social marketing failures.We conducted ten semi-structured interviews with social marketing practitioners recruited using a purposive sampling technique. We identify four elements responsible for the failure of social marketing programs, each centered on the planning and implementation stage. Firstly, formative research at the earliest stages of program planning is often neglected, resulting in a limited understanding of the target audience. Relatedly, extant research is frequently overlooked during this early planning stage, and this failure to use available social marketing theory and frameworks can result in program performing poorly. Thirdly, for a program to be successful, it must be congruent with the goals of the wider environment and infrastructure within which it is situated; adopting too narrow a focus can also result in a limited impact or program failure. Lastly, we found a common issue relating of stakeholder mismanagement, specifically around issues of power imbalance and mismanaged expectations resulting in social marketing program failing to launch. Researchers and practitioners must acknowledge that social marketing programs do indeed fail but recognize that in these failings lies insight into how to enhance future practice
The Quality of Doctoral Training and Employability of Doctorate Holders: The Views of Doctoral Candidates and Junior Researchers
Arbitraging a Discriminatory Labor Market: Black Workers at the Ford Motor Company, 1918â1947
The 1918-47 employee records of the Ford Motor Company provide a rare opportunity to study a firm willing to hire black workers when similar firms would not. The evidence suggests that Ford did profit from discrimination elsewhere, but not by paying blacks less than whites. An apparent "wage-equity constraint" prevailed, resulting in virtually no racial variation in wages inside Ford. An implication was that blacks quit Ford jobs less often than whites, holding working conditions constant. Arbitrage profit came from exploiting this nonwage margin, as Ford placed blacks in hot, dangerous foundry jobs where quit rates were generally high
XO-5b: A Transiting Jupiter-sized Planet With A Four Day Period
The star XO-5 (GSC 02959-00729, V=12.1, G8V) hosts a Jupiter-sized,
Rp=1.15+/-0.12 Rjup, transiting extrasolar planet, XO-5b, with an orbital
period of P=4.187732+/-0.00002 days. The planet mass (Mp=1.15+/-0.08 Mjup) and
surface gravity (gp=22+/-5 m/s^2) are significantly larger than expected by
empirical Mp-P and Mp-P-[Fe/H] relationships. However, the deviation from the
Mp-P relationship for XO-5b is not large enough to suggest a distinct type of
planet as is suggested for GJ 436b, HAT-P-2b, and XO-3b. By coincidence XO-5
overlies the extreme H I plume that emanates from the interacting galaxy pair
NGC 2444/NGC 2445 (Arp 143).Comment: 10 pages, 9 Figures, Submitted to Ap
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