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K F Boersma,
D J Jacob,
E J Bucsela,
A E Perring,
R Dirksen,
R J Van Der A,
R M Yantosca, R J Park,
M O Wenig,
T H Bertram,
R C Cohen
[show abstract]
[hide abstract]
ABSTRACT: We compare tropospheric NO 2 column measurements from the Ozone Monitoring Instrument (OMI) aboard the EOS Aura satellite with coincident in situ aircraft measurements on vertical spirals over the southern United States, Mexico, and the Gulf of Mexico during the INTEX-B campaign in March 2006. Good correlation with no significant bias (r 2 ¼ 0:67, slope ¼ 0:99 AE 0:17, n ¼ 12) is found for the ensemble of comparisons when the aircraft could spiral sufficiently low to sample most of the NO 2 column. Urban spirals where large extrapolations were needed below the aircraft floor (1000 ft) showed poorer agreement. We use the OMI observations together with a global chemical transport model (GEOS-Chem) to estimate emissions of nitrogen oxides over the eastern United States and Mexico in March 2006. Comparison to EPA's National Emissions Inventory 1999 (NEI99) calls for a decrease in power plant emissions and an increase in on-road vehicle emissions relative to that inventory. The rise in vehicular emissions is offsetting the reduction in power plant and industry emissions. These findings are consistent with independent assessments. Our OMI-derived emission estimates for Mexico are higher by a factor of 2:0 AE 0:5 than bottom-up emissions, similar to a comparison between the recently released Mexican NEI99 inventory and the bottom-up showing that the Mexican NEI99 inventory is 1.6–1.8Â higher.
Atmospheric Environment. 01/2008; 42:4480-4497.
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[show abstract]
[hide abstract]
ABSTRACT: To determine the effects of cataract extraction with intraocular lens placement on scanning laser polarimetry of the peripapillary nerve fiber layer.
Cohort study.
Thirty-four eyes of 33 patients undergoing phacoemulsification cataract surgery with intraocular lens were imaged using the GDx Nerve Fiber Analyzer within 4 weeks before and at least 4 weeks after cataract surgery. Preoperative and postoperative mean images were compared. The effects of cataract severity and type, and intraocular lens material, were also examined.
Comparison of preoperative and postoperative mean scanning laser polarimetry measurements revealed that eyes in which acrylic intraocular lenses (n = 11) were placed had a significant increase in scanning laser polarimetry for the total band circumference, and superior, inferior, and nasal quadrants (P < or =.041). Placement of silicone (n = 15) and polymethylmethacrylate (n = 8) intraocular lenses did not result in statistically significant changes in scanning laser polarimetry measurements. However, eight of 34 eyes (23.5%) had changes of 15% or more postoperatively in the total circumference measurement, including eyes with acrylic, silicone, and polymethylmethacrylate intraocular lenses.
Cataract extraction with intraocular lens was associated with a statistically significant change in mean scanning laser polarimetry values in eyes that received an acrylic intraocular lens. In individual patients, clinically important changes (15% or greater) in scanning laser polarimetry measurements were not uncommon irrespective of intraocular lens type. New baseline scanning laser polarimetry measurements may be warranted in eyes that undergo cataract extraction with intraocular lens.
American Journal of Ophthalmology 10/2001; 132(4):507-11. · 4.22 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: To investigate visual field progression in patients with initially unilateral glaucomatous visual field loss, and to determine risk factors for progression.
Retrospective observational case series.
Forty-eight consecutive patients with primary open-angle glaucoma, pseudoexfoliative glaucoma, or pigmentary glaucoma, seen over an 18-month period, who initially had unilateral visual field loss as defined by use of modified Anderson criteria. Patients were followed with standard Humphrey perimetry for a minimum of 2 years.
Progression was defined by use of modified Anderson criteria, and Advanced Glaucoma Intervention Study (AGIS) and Collaborative Initial Glaucoma Treatment Study scores.
Visual field progression.
Three patients (6.2%) had fellow eye progression over a mean follow-up of 76 months and duration of disease of 8.7 years. Fellow eye progression correlated with progression of the first-affected eye (P = 0.044). Ten patients (21%) had progression of the first-affected eye; these eyes had a larger initial cup/disc ratio compared with stable eyes (P = 0.041). Increasing initial AGIS score was associated with progression (P: = 0.003). Kaplan-Meier survival analysis estimated the risk of progression at 5 years to be 25% in first-affected eyes and 7.2% in fellow eyes.
In this population, the risk of fellow eye progression in patients with initially unilateral visual field loss from open-angle glaucoma is low. Progression is higher in eyes with visual field loss at initial testing, and the risk of progression increases as the level of initial visual field loss increases.
Ophthalmology 10/2000; 107(9):1688-92. · 5.45 Impact Factor
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K.F. Boersma,
D.J. Jacob,
E.J. Bucsela,
A.E. Perring,
R. Dirksen,
R.J. van der A,
R.M. Yantosca, R.J. Park,
M.O. Wenig,
T.H. Bertram,
R.C. Cohen
[show abstract]
[hide abstract]
ABSTRACT: We compare tropospheric NO2 column measurements from the Ozone Monitoring Instrument (OMI) aboard the EOS Aura satellite with coincident in situ aircraft measurements on vertical spirals over the southern United States, Mexico, and the Gulf of Mexico during the INTEX-B campaign in March 2006. Good correlation with no significant bias (r2=0.67, slope=0.99±0.17, n=12) is found for the ensemble of comparisons when the aircraft could spiral sufficiently low to sample most of the NO2 column. Urban spirals where large extrapolations were needed below the aircraft floor (1000 ft) showed poorer agreement. We use the OMI observations together with a global chemical transport model (GEOS-Chem) to estimate emissions of nitrogen oxides over the eastern United States and Mexico in March 2006. Comparison to EPA's National Emissions Inventory 1999 (NEI99) calls for a decrease in power plant emissions and an increase in on-road vehicle emissions relative to that inventory. The rise in vehicular emissions is offsetting the reduction in power plant and industry emissions. These findings are consistent with independent assessments. Our OMI-derived emission estimates for Mexico are higher by a factor of 2.0±0.5 than bottom-up emissions, similar to a comparison between the recently released Mexican NEI99 inventory and the bottom-up showing that the Mexican NEI99 inventory is 1.6–1.8× higher.
Atmospheric Environment.
-
K F Boersma,
D J Jacob,
E J Bucsela,
A E Perring,
R Dirksen,
R J Van Der A,
R M Yantosca, R J Park,
M O Wenig,
T H Bertram,
R C Cohen
[show abstract]
[hide abstract]
ABSTRACT: We compare tropospheric NO 2 column measurements from the Ozone Monitoring Instrument (OMI) aboard the EOS Aura satellite with coincident in situ aircraft measurements on vertical spirals over the southern United States, Mexico, and the Gulf of Mexico during the INTEX-B campaign in March 2006. Good correlation with no significant bias (r 2 =0.67, slope=0.99±0.17, n=12) is found for the ensem-ble of comparisons when the aircraft could spiral sufficiently low to sample most of the NO 2 column. Urban spirals where large extrapolations were needed below the aircraft floor (1000 feet) showed poorer agreement. We use the OMI observa-tions together with a global chemical transport model (GEOS-Chem) to estimate emissions of nitrogen oxides over the eastern United States and Mexico in March 2006. Comparison to EPA's National Emissions Inventory 1999 (NEI99) calls for a decrease in power plant emissions and an increase in on-road vehicle emissions rel-ative to that inventory. The rise in vehicular emissions is offsetting the reduction in power plant and industry emissions. These findings are consistent with independent assessments. Our OMI-derived emission estimates for Mexico are higher by a factor of 2.0±0.5 than bottom-up emissions, similar to a comparison between the recently released Mexican NEI99 inventory and the bottom-up showing that the Mexican NEI99 inventory is 1.6-1.8× higher.
