Identifying and assessing corporate employment variables that influence community resilience: A novel model.

Quantifying the concept of disaster resilience on a local level is becoming more critical as vulnerable communities face more frequent and intense disasters due to climate change. In the United States (US), corporations are often evaluated using social justice or environmental sustainability matrices for financial investment consideration. However, there are few tools available to measure a corporation's contribution to disaster resilience on a local level. This study includes a focused literature review of employment variables that contribute to community resilience and a national survey that asked US emergency managers to rank the variables they believe have the greatest influence on individual resilience. A novel corporate community resilience model that ranks corporate contributions to disaster resilience in the communities where they operate was developed and then tested against data from five employment sectors from the same area. This model can be used by stakeholders to better understand how corporations can most efficiently contribute to county- and subcounty-level disaster resilience. The metrics used in this study are universal and translative, and thus, the development of this resilience model has global disaster resilience implications.

Night driving simulation in a randomized prospective comparison of Visian toric implantable collamer lens and conventional PRK for moderate to high myopic astigmatism.

PURPOSE: To compare changes in simulated night driving performance after Visian Toric Implantable Collamer Lens (TICL; STAAR Surgical) implantation and photorefractive keratectomy (PRK) for the correction of moderate to high myopic astigmatism. METHODS: This prospective, randomized study consisted of 43 eyes implanted with the TICL (20 bilateral cases) and 45 eyes receiving conventional PRK (VISX Star S3 excimer laser) with mitomycin C (22 bilateral cases) for moderate to high myopia (-6.00 to -20.00 diopters[D] sphere) measured at the spectacle plane and 1.00 to 4.00 D of astigmatism. As a substudy, 27 eyes of 14 TICL patients and 41 eyes of 21 PRK patients underwent a simulated night driving test. The detection and identification distances of road signs and hazards with the Night Driving Simulator (Vision Sciences Research Corp) were measured with and without a glare source before and 6 months after each procedure. RESULTS: No significant difference was noted in the pre- to postoperative Night Driving Simulator in detection distances with and without the glare source between the TICL and PRK groups. The differences in identification distances without glare were significantly better for business and traffic road signs and pedestrian hazards in the TICL group relative to the PRK group whereas with glare, only the pedestrian hazards were significantly better. A clinically relevant change of Night Driving Simulator performance (>0.5 seconds change in ability to identify tasks postoperatively) was significantly better in the TICL group (with and without glare) for all identification tasks. CONCLUSIONS: The TICL performed better than conventional PRK in the pre- to postoperative Night Driving Simulator testing with and without a glare source present.

US FDA clinical trial of the Tetraflex potentially accommodating IOL: comparison to concurrent age-matched monofocal controls.

PURPOSE: To assess the efficacy of the Tetraflex (Lenstec Inc) intraocular lens (IOL) to provide enhanced near reading ability and spectacle independence relative to a monofocal control IOL in bilaterally implanted eyes tested binocularly. METHODS: A prospective, age-matched, non-randomized US Food and Drug Administration clinical trial of 255 Tetraflex and 101 monofocal IOL control patients was performed. To date, 239 Tetraflex and 96 control patients were examined at 12 months postoperatively. RESULTS: At 12 months postoperative, the Tetraflex patients read better than the controls at print sizes of 20/80 (P=.04), 20/63 (P=.01), 20/50 (P<.001), 20/40 (P=.001), 20/32 (P<.001), and 20/25 (P=.001). The proportion of patients reading at a speed of ≥80 words per minute was significantly higher with the Tetraflex IOL (P=.003). Ninety-six percent of Tetraflex patients reported never wearing glasses for distance compared with 80% of control patients (P<.001). Seventy-five percent of the Tetraflex patients reported near spectacle wear either never or only occasionally for small print and/or dim light (21% never) compared with 46% of control patients (P<.001) (9% never). Near add power requirement for corrected near visual acuity was less in the Tetraflex group (P<.001); 28% of Tetraflex patients required ≤1.25 diopters of near add, compared to only 7% of control patients. Spectacle independence, as measured by the proportion of patients with uncorrected distance visual acuity of 20/25 or better and various degrees of uncorrected near visual acuity, was also significantly better (P<.001) as was distance-corrected near visual acuity (P<.001). CONCLUSIONS: The results support the efficacy of the Tetraflex IOL to provide enhanced near reading ability and spectacle independence relative to a monofocal IOL control.

Pulsed field gradient nuclear magnetic resonance study of time-dependent diffusion behavior and exchange of lipids in planar-supported lipid bilayers.

This work reports the direct experimental observation of lipid exchange between liquid-ordered domains and their liquid-disordered surroundings in 3-component planar-supported multibilayers (1,2-dioleoyl-sn-glycerol-3-phosphocholine/1,2-dipalmitoyl-sn-glycero-3-phosphocholine/cholesterol). The measurements of lipid lateral diffusion and exchange were carried out using proton pulsed field gradient (PFG) NMR spectroscopy with high field strength (17.6 T) and high gradient amplitudes (up to 30 T/m). Application of large gradients affords the use of sufficiently small diffusion times under the condition that the width of the gradient pulses is much smaller than the diffusion time. As a result, PFG NMR studies of time-dependent diffusion behavior in lipid bilayers become possible over submicrometer length scales of displacements, which are comparable with the domain size. Comparison of the PFG NMR diffusion data and the corresponding results of dynamic Monte Carlo simulations allowed for the estimation of domain boundary permeability and domain size at temperatures near the transition temperature for the studied bilayers.

Functional reading acuity and performance: Comparison of 2 accommodating intraocular lenses.

PURPOSE: To compare functional reading acuity and speed with 2 models of accommodating intraocular lenses (IOLs). SETTING: Four of 12 investigative sites in a U.S. Food and Drug Administration (FDA) clinical study. METHODS: In this observational study, which was part of an ongoing FDA clinical trial, the MNRead functional reading test was used to compare the reading performance of patients with bilateral Tetraflex IOLs (Group 1) and a consecutive series of patients with bilateral Crystalens IOLs (Group 2) presenting at approximately 1 year postoperatively at 4 ophthalmic practices. The 2 groups were well matched for age, sex, mean postoperative time, and mean level of postoperative corrected distance visual acuity. All examinations were scored at a central reading center. RESULTS: Group 1 comprised 96 patients and Group 2, 55 patients. Patients in Group 1 read better than those in Group 2 at print sizes of 20/63 (P = .004), 20/50 (P = .002), 20/40 (P = .001), 20/32 (P = .003), and 20/25 (P = .001). A statistically significantly higher proportion of patients in Group 1 than in Group 2 read 80 words per minute or more throughout the range of print sizes (P = .002). CONCLUSION: Near reading ability was better with the Tetraflex accommodating IOL than with the Crystalens accommodating IOL at all print sizes between 20/25 and 20/63.

Comparison of the toric implantable collamer lens and custom ablation LASIK for myopic astigmatism.

PURPOSE: To compare the results of wavefront-guided custom LASIK and the Toric Implantable Collamer Lens (TICL) in the correction of myopic astigmatism. METHODS: This observational, non-randomized study compared clinical efficacy results from the TICL's US Food and Drug Administration Clinical Trial and published Summaries of Safety and Effectiveness of two wavefront-guided lasers: STAR S4 CustomVue excimer laser system (VISX Inc) and LADARVision4000 CustomCornea excimer laser system (Alcon Laboratories Inc). Preoperative myopic refractive error was divided into two groups: -3.00 to -7.00 diopters (D) and -7.00 to -11.00 D. RESULTS: The percentage of eyes with uncorrected visual acuity (UCVA) of 20/20 and 20/40 and predictability of manifest refraction spherical equivalent within +/- 0.50 and +/- 1.00 D in the three groups was similar with only one statistically significant difference (TICL versus Alcon within +/- 1.00 D: 97% versus 82%; P = .008). The TICL had significantly better postoperative best spectacle-corrected visual acuity (BSCVA) compared to preoperative BSCVA than both the VISX CustomVue and Alcon CustomCornea (P < .001). The TICL postoperative UCVA outcomes compared to preoperative BSCVA were significantly better than Alcon CustomCornea outcomes (P < .001). Additionally, almost half (48%) of the TICL cases had improvement in postoperative UCVA compared to preoperative BSCVA, whereas only 23% of the Alcon CustomCornea eyes showed improvement. CONCLUSIONS: Although comparable in clinical efficacy outcomes, the TICL had a significantly better postoperative improvement in BSCVA and significantly better postoperative UCVA than preoperative BSCVA. The TICL can be considered as an alternative to LASIK through the full range of use.

Application of pulsed field gradient NMR with high gradient strength for studies of self-diffusion in lipid membranes on the nanoscale.

This work demonstrates the feasibility of noninvasive studies of lipid self-diffusion in model lipid membranes on the nanoscale using proton pulsed field gradient (PFG) NMR spectroscopy with high (up to 35 T/m) gradient amplitudes. Application of high gradients affords for the use of sufficiently small diffusion times under the conditions when the width of the gradient pulses is much smaller than the diffusion time. As a result, PFG NMR studies of partially restricted or anomalous diffusion in lipid bilayers become possible over length scales as small as 100 nm. This length scale is important because it is comparable to the size of membrane domains, or lipid rafts, which are believed to exist in biomembranes. In this work, high-gradient PFG NMR has been applied to study lipid self-diffusion in three-component planar-supported multibilayers (1,2-dioleoyl- sn-glycerol-3-phosphocholine/sphingomyelin/cholesterol). The degree of lipid orientation in the bilayers was determined with (31)P NMR. A special insert was designed to mechanically align the multibilayer stack at the magic angle with respect to the direction of the constant magnetic field to address the detrimental effects of proton dipole-dipole interactions on the NMR signal. This insert is an alternative to the conventional method of magic angle orientation of lipid membranes, the goniometer probe, which is not compatible with commercial high-gradient coils because of the lack of space in the magnet bore. Macroscopic orientation of the multibilayer stacks using the insert was confirmed with (1)H NMR spectroscopic studies and the comparison of results obtained from identical experiments using a goniometer probe for orientation. Diffusion studies were carried out at three different constant magnetic field strengths ( B 0) over a range of temperatures and diffusion times. The measured diffusivities were found to be in agreement with the data obtained previously by techniques that are limited to much larger length scales of diffusion observation than high-gradient PFG NMR.

Randomized prospective comparison of visian toric implantable collamer lens and conventional photorefractive keratectomy for moderate to high myopic astigmatism.

PURPOSE: To compare the Visian Toric Implantable Collamer Lens (TICL), a toric phakic intraocular lens (IOL), and photorefractive keratectomy (PRK) in the correction of moderate to high myopic astigmatism. METHODS: This prospective, randomized study consisted of 43 eyes implanted with the TICL (20 bilateral cases) and 45 eyes receiving PRK with mitomycin C (22 bilateral cases) with moderate to high myopia (-6.00 to -20.00 diopters [D] sphere) measured at the spectacle plane and 1.00 to 4.00 D of astigmatism. All patient treatment and follow-up occurred at the Naval Medical Center San Diego. Study follow-up was 1 day, 1 week, 1, 3, 6, and 12 months postoperative. RESULTS: Mean best spectacle-corrected visual acuity (BSCVA), change in BSCVA, proportion of cases with improvement of 1 or more lines of BSCVA, proportion of cases with BSCVA and uncorrected visual acuity (UCVA) 20/12.5 or better, proportion of cases with BSCVA and UCVA 20/16 or better (6 months, 88% vs 54%, P=.002), and predictability +/-1.00 D (6 months, 100% vs 67%, P<.001) were all significantly better in the TICL group than the PRK group at all time periods studied postoperatively. Similarly, contrast sensitivity, tested at both the 5% photopic level and the 25% mesopic level, was significantly better at all postoperative time points in the TICL group. Mean spherical equivalent refraction was closer to emmetropia (0.28+/-0.41 vs 0.76+/-0.86, P=.005), and predictability +/-0.50 D and stability of manifest refraction (+/-0.50 D and +/-1.00 D) were significantly better in the TICL group at all postoperative visits through 6 months. Mean astigmatism correction at 6 months was not significantly different between the two groups (0.52+/-0.33 vs 0.46+/-0.35, P=.450). CONCLUSIONS: The TICL performed better than PRK in all measures of safety (BSCVA), efficacy (UCVA), predictability, and stability in this comparison, supporting the TICL as a viable alternative to existing refractive surgical treatments.

Near visual acuity for everyday activities with accommodative and monofocal intraocular lenses.

PURPOSE: To determine the levels of functional near visual acuity required for everyday social reading activities and to compare the levels to those attained with accommodative and monofocal intraocular lenses (LOLs). METHODS: Font size equivalencies of an Early Treatment Diabetic Retinopathy Study near chart and a variety of commonly read print objects were determined and correlated to the findings of distance-corrected near vision measurements with 2 accommodative (Tetraflex, 1CU) and 1 monofocal (Acrysof MA30) IOLs. RESULTS: The smallest print objects studied were sweetener packets with type between 20/40 (Jaeger [J] 5) and 20/50 (J6). Type in classified ads, stock quotations, and pocket bibles was 20/50 (J6), type in a telephone directory was 20/63 (J8), and type in standard newspapers, journals, and magazines was 20/80 (J9). Tested monocularly, 88% of Tetraflex, 40% of ICU, and 7% of Acrysof MA30 eyes had distance-corrected near vision sufficient to read newspaper and telephone directory print, and 63% of Tetraflex, 30% of 1CU, and 0% of Acrysof MA30 eyes could read classified ads, stock quotations, and pocket bibles, respectively. Tested binocularly after bilateral implantation, 96% of Tetraflex patients could read telephone directory print and 89% could read ads, stock quotations, and pocket bibles. CONCLUSIONS: Functional near visual acuity is not equivalent to the bottom-line objective at 20/20 (J1) near visual acuity. No print size was found at or smaller than 20/40 (J5), indicating that a requirement of nearly perfect near visual acuity, while desirable, may not be necessary for patients' social reading needs for accommodative IOLs.

Probing lateral diffusion in lipid membranes on nanoscale by PFG NMR with high gradient strength.

This work demonstrates the feasibility of noninvasive studies of diffusion on a submicrometer length scale in aligned model lipid membranes using pulsed field gradient nuclear magnetic resonance with ultrahigh (up to 35 T/m) gradient strength. Application of such gradients allows the use of sufficiently small diffusion times under conditions of narrow-pulse approximation. As a result, monitoring anomalous or restricted diffusion in lipid membranes on a length scale in the range of 100 nm becomes possible. The ability to study diffusion in lipid membranes on this length scale is very important because it is comparable with the size of biologically relevant domains (i.e., rafts), which are believed to exist in biomembranes.

Visual performance results after Tetraflex accommodating intraocular lens implantation.

PURPOSE: To present the clinical results that demonstrate the efficacy of the Tetraflex accommodative intraocular lens (IOL) in providing both enhanced distance and near acuity. DESIGN: Single-center prospective data collection performed in Manchester, United Kingdom. PARTICIPANTS: A series of 95 eyes of 59 patients implanted with the Tetraflex lens was performed by a single surgeon. Thirty-six of these cases were implanted bilaterally. INTERVENTION: Implantation of the Tetraflex accommodative IOL. MAIN OUTCOME MEASURES: Prospective data collection included both uncorrected distance visual acuity (UCDVA) and uncorrected near visual acuity (UCNVA) testing, manifest refraction, best-corrected distance visual acuity (BCDVA), distance corrected near visual acuity (DCNVA), and the amplitude of accommodation. Intraoperative and postoperative complications also were reported. RESULTS: At 6 months after surgery, 63% of all cases achieved a DCNVA of 20/40 or better. Virtually all of the patients had at least 1 diopter (D) of accommodative amplitude (98% at 1 month; 100% at 3 and 6 months); 75.7% had at least 2 D at 6 months after surgery. At 6 months or later, 92.2% had 20/40 or better UCDVA. The proportion of cases achieving a UCNVA of 20/40 or better remained relatively constant at 45% to 47%. At 6 months and later, 98.7% had a BCDVA of 20/40 or better. In the bilaterally implanted series, at 1 month after surgery, all patients had at least 1 D of accommodative ability; 96% had at least 2 D at 6 months. One hundred percent achieved a BCDVA, 89.3% achieved a DCNVA, and 74.1% achieved a UCNVA of 20/40 or better at 6 months after surgery. CONCLUSIONS: The Tetraflex accommodating IOL provides enhanced near vision with good distance vision 6 months after surgery.

Microemulsions of triglyceride-based oils: The effect of co-oil and salinity on phase diagrams.

Microemulsification of triglyceride-based oil is challenging due to the formation of undesirable phases such as macroemulsions, liquid crystals, or sponge phases. This research evaluates the formation of artificial sebum microemulsions using linker molecules, with the addition of co-oil to help enhance sebum solubilization. The microemulsion consists of a lipophilic linker (sorbitan monooleate), a hydrophilic linker (hexylglucocide), a main surfactant (sodium dioctyl sulfosuccinate), a co-oil, and artificial sebum. The effect of adding co-oil to the phase behavior and the microstructure of the resulting microemulsion is described. The effect of several types of co-oil is also studied; the co-oils evaluated here are squalene, squalane, isopropyl myristate, and ethyl laurate. The effect of salinity on the microemulsion phase behavior is also presented. Fish diagrams are obtained by plotting total surfactant/linker concentration as a function of sebum fraction in the oil mixture (co-oil + sebum). Different microemulsion types (Winsor Types I, II, III, and IV) are formed, depending on the total surfactant/linker concentration and the fraction of co-oil in the oil mixture. Winsor Type IV (single-phase) microemulsions are observed at high surfactant/linker concentrations. These single-phase, isotropic, and low-viscous fluids are particularly useful for cleansing and delivery of functional ingredients in skin care products. Salt addition shifts the fish diagram towards more hydrophobic oil systems and higher surfactant/linker concentrations.