Inequality in Beijing: A Spatial Multilevel Analysis of Perceived Environmental Hazard and Self-Rated Health

Environmental pollution is a major problem in China, subjecting people to significant health risk. However, surprisingly little is known about how these risks are distributed spatially or socially. Drawing upon a large-scale survey conducted in Beijing in 2013, we examine how environmental hazards and health, as perceived by residents, are distributed at fine (sub-district) scale in urban Beijing, and investigate association between hazards, health and geographical context. A Bayesian spatial multilevel logistic model is developed to account for spatial dependence in unobserved contextual influences (‘neighbourhood effects’) on health. Results reveal robust associations between exposure to environmental hazards and health. A unit decrease on a 5-point Likert scale in exposure is associated with increases of 15.2% (air pollution), 17.5% (noise) and 9.3% (landfills) in the odds of reporting good health, with marginal groups including migrant workers reporting greater exposure. Health inequality is also evident, and associated with age, income, educational attainment and housing characteristics. Geographical context (neighbourhood features like local amenity) also plays a role in shaping the social distribution of health inequality. Results are discussed in the context of developing environmental justice policy within a Chinese social market system that experiences tension between its egalitarian roots and its pragmatic approach to tackling grand public policy challenges

Technical Note: A comparison of central and peripheral intraocular pressure using rebound tonometry

Purpose: To compare central and peripheral intraocular pressure (IOP) readings obtained with rebound tonometry.Methods: Intraocular pressure was measured on the right eye of 153 patients (65 males, 88 females), aged from 21 to 85 years (mean +/- S.D., 55.5 +/- 15.2 years) with the ICare rebound tonometer at centre, and 2 mm from the limbus (in the nasal and temporal regions along the 0-180O corneal meridian).Results: Intraocular pressure values obtained with the ICare were 14.9 +/- 2.8; 14.1 +/- 2.5 and 14.5 +/- 2.7 mmHg at centre, nasal and temporal corneal locations, respectively. On average, nasal and temporal IOP readings were 0.75 and 0.37 mmHg lower than the central reading (p 0.05, respectively). A highly significant correlation was found between central and peripheral measurements in nasal (r(2) = 0.905; p < 0.001) and temporal (r(2) = 0.879; p < 0.001) regions along the horizontal meridian. Almost 80% of patients presented nasal IOP values within +/- 1 mmHg of the central value.Conclusions: Intraocular pressure values measured with the ICare (R) rebound tonometer on the nasal corneal region is slightly lower on average and highly correlated with IOP values recorded at corneal centre. Both nasal and temporal readings are in good agreement with central IOP, and could be used to obtain a reliable estimate of rebound IOP in corneas where central readings cannot be taken.- (undefined

PG 1115+080: variations of the A2/A1 flux ratio and new values of the time delays

We report the results of our multicolor observations of PG 1115+080 with the 1.5-m telescope of the Maidanak Observatory (Uzbekistan, Central Asia) in 2001-2006. Monitoring data in filter R spanning the 2004, 2005 and 2006 seasons (76 data points) demonstrate distinct brightness variations of the source quasar with the total amplitude of almost 0.4 mag. Our R light curves have shown image C leading B by 16.4d and image (A1+A2) by 12d that is inconsistent with the previous estimates obtained by Schechter et al. in 1997 - 24.7d between B and C and 9.4d between (A1+A2) and C. The new values of time delays in PG 1115+080 must result in larger values for the Hubble constant, thus reducing difference between its estimates taken from the gravitational lenses and with other methods. Also, we analyzed variability of the A2/A1 flux ratio, as well as color changes in the archetypal "fold" lens PG 1115+080. We found the A1/A2 flux ratio to grow during 2001-2006 and to be larger at longer wavelengths. In particular, the A2/A1 flux ratio reached 0.85 in filter I in 2006. We also present evidence that both the A1 and A2 images might have undergone microlensing during 2001-2006, with the descending phase for A1 and initial phase for A2. We find that the A2/A1 flux ratio anomaly in PG 1115 can be well explained both by microlensing and by finite distance of the source quasar from the caustic fold.Comment: 14 pages, 7 figures, 8 tables, Accepted for publication in MNRA

Circulating markers of arterial thrombosis and late-stage age-related macular degeneration: a case-control study.

PURPOSE: The aim of this study was to examine the relation of late-stage age-related macular degeneration (AMD) with markers of systemic atherothrombosis. METHODS: A hospital-based case-control study of AMD was undertaken in London, UK. Cases of AMD (n=81) and controls (n=77) were group matched for age and sex. Standard protocols were used for colour fundus photography and to classify AMD; physical examination included height, weight, history of or treatment for vascular-related diseases and smoking status. Blood samples were taken for measurement of fibrinogen, factor VIIc (FVIIc), factor VIIIc, prothrombin fragment F1.2 (F1.2), tissue plasminogen activator, and von Willebrand factor. Odds ratios from logistic regression analyses of each atherothrombotic marker with AMD were adjusted for age, sex, and established cardiovascular disease risk factors, including smoking, blood pressure, body mass index, and total cholesterol. RESULTS: After adjustment FVIIc and possibly F1.2 were inversely associated with the risk of AMD; per 1 standard deviation increase in these markers the odds ratio were, respectively, 0.62 (95% confidence interval 0.40, 0.95) and 0.71 (0.46, 1.09). None of the other atherothrombotic risk factors appeared to be related to AMD status. There was weak evidence that aspirin is associated with a lower risk of AMD. CONCLUSIONS: This study does not provide strong evidence of associations between AMD and systematic markers of arterial thrombosis, but the potential effects of FVIIc, and F1.2 are worthy of further investigation

End-functionalized poly(vinylpyrrolidone) for ligand display in lateral flow device test lines

Lateral flow devices are rapid (and often low cost) point-of-care diagnostics─the classic example being the home pregnancy test. A test line (the stationary phase) is typically prepared by the physisorption of an antibody, which binds to analytes/antigens such as viruses, toxins, or hormones. However, there is no intrinsic requirement for the detection unit to be an antibody, and incorporating other ligand classes may bring new functionalities or detection capabilities. To enable other (nonprotein) ligands to be deployed in lateral flow devices, they must be physiosorbed to the stationary phase as a conjugate, which currently would be a high-molecular-weight carrier protein, which requires (challenging) chemoselective modifications and purification. Here, we demonstrate that poly(vinylpyrrolidone), PVP, is a candidate for a polymeric, protein-free test line, owing to its unique balance of water solubility (for printing) and adhesion to the nitrocellulose stationary phase. End-functionalized PVPs were prepared by RAFT polymerization, and the model capture ligands of biotin and galactosamine were installed on PVP and subsequently immobilized on nitrocellulose. This polymeric test line was validated in both flow-through and full lateral flow formats using streptavidin and soybean agglutinin and is the first demonstration of an “all-polymer” approach for installation of capture units. This work illustrates the potential of polymeric scaffolds as anchoring agents for small-molecule capture agents in the next generation of robust and modular lateral flow devices and that macromolecular engineering may provide real benefit

Prevalence of refractive errors among school-going children in a multistate study in India

Aim Much existing data on childhood refractive error prevalence in India were gathered in local studies, many now dated. The aim of this study was to estimate the prevalence, severity and determinants of refractive errors among school-going children participating in a multistate vision screening programme across India. Methods In this cross-sectional study, vision screening was conducted in children aged 5–18 years at schools in five states using a pocket vision screener. Refractive error was measured using retinoscopy, and subjective refraction and was defined both by spherical equivalent (SE) and spherical ametropia, as myopia ≤−0.5 diopters (D), hyperopia ≥+1.0 D and/or astigmatism as >0.5 D. Data from the eye with less refractive error were used to determine prevalence. Results Among 2 240 804 children (50.9% boys, mean age 11.5 years, SD ±3.3), the prevalence of SE myopia was 1.57% (95% CI 1.54% to 1.60%) at 5–9 years, 3.13% (95% CI 3.09% to 3.16%) at 10–14 years and 4.8% (95% CI 4.73% to 4.86%) at 15–18 years. Hyperopia prevalence was 0.59% (95% CI 0.57% to 0.61%), 0.54% (95% CI 0.53% to 0.56%) and 0.39% (95% CI 0.37% to 0.41%), respectively. When defined by spherical ametropia, these values for myopia were 0.84%, 2.50% and 4.24%, and those for hyperopia were 2.11%, 2.41% and 2.07%, respectively. Myopia was associated with older age, female gender, private school attendance, urban location and state. The latter appeared to be driven by higher literacy rates. Conclusions Refractive error, especially myopia, is common in India. Differences in prevalence between states appear to be driven by literacy rates, suggesting that the burden of myopia may rise as literacy increases

Substructures in lens galaxies: PG1115+080 and B1555+375, two fold configurations

We study the anomalous flux ratio which is observed in some four-image lens systems, where the source lies close to a fold caustic. In this case two of the images are close to the critical curve and their flux ratio should be equal to unity, instead in several cases the observed value differs significantly. The most plausible solution is to invoke the presence of substructures, as for instance predicted by the Cold Dark Matter scenario, located near the two images. In particular, we analyze the two fold lens systems PG1115+080 and B1555+375, for which there are not yet satisfactory models which explain the observed anomalous flux ratios. We add to a smooth lens model, which reproduces well the positions of the images but not the anomalous fluxes, one or two substructures described as singular isothermal spheres. For PG1115+080 we consider a smooth model with the influence of the group of galaxies described by a SIS and a substructure with mass $\sim 10^{5} M_{\odot}$ as well as a smooth model with an external shear and one substructure with mass $\sim 10^{8} M_{\odot}$ . For B1555+375 either a strong external shear or two substructures with mass $\sim 10^{7} M_{\odot}$ reproduce the data quite well.Comment: 26 pages, updated bibliography, Accepted for publication in Astrophysics & Space Scienc

Ocular fundus pathology and chronic kidney disease in a Chinese population

<p>Abstract</p> <p>Background</p> <p>Previous study indicated a high prevalence of ocular fundus pathology among patients with chronic kidney disease (CKD), while the relationship between them has never been explored in a Chinese Population.</p> <p>Methods</p> <p>This cross-sectional study included 9 670 participants enrolled in a medical screening program. Ocular fundus examination was performed by ophthalmologists using ophthalmoscopes. The presence of eGFR less than 60 mL/min/1.73 m²and/or proteinuria was defined as CKD.</p> <p>Results</p> <p>Compared to participants without CKD, participants with CKD had higher prevalence of retinopathy (28.5% vs. 16.3%, P < 0.001), glaucoma suspect (3.1% vs. 1.8%, P = 0.004), age-related macular degeneration (1.7% vs. 0.9%, P = 0.01) and overall eye pathology (32.0% vs. 19.4%, P < 0.001). After adjusting for potential confounders, the odds ratio of proteinuria for overall eye pathology and retinopathy was 1.29 (95% confidence interval [CI] 1.07-1.55) and 1.37 (95% CI 1.12-1.67), respectively. The results were robust after excluding participants with hypertension or with diabetes.</p> <p>Conclusions</p> <p>Ocular fundus pathology is common among Chinese patients with CKD. Regular eye exam among persons with proteinuria is warranted.</p

Poly(vinyl alcohol) molecular bottlebrushes nucleate ice

Ice binding proteins (IBP) have evolved to limit the growth of ice but also to promote ice formation by ice-nucleating proteins (INPs). IBPs, which modulate these seemingly distinct processes, often have high sequence similarities, and molecular size/assembly is hypothesized to be a crucial determinant. There are only a few synthetic materials that reproduce INP function, and rational design of ice nucleators has not been achieved due to outstanding questions about the mechanisms of ice binding. Poly(vinyl alcohol) (PVA) is a water-soluble synthetic polymer well known to effectively block ice recrystallization, by binding to ice. Here, we report the synthesis of a polymeric ice nucleator, which mimics the dense assembly of IBPs, using confined ice-binding polymers in a high-molar-mass molecular bottlebrush. Poly(vinyl alcohol)-based molecular bottlebrushes with different side-chain densities were synthesized via a combination of ring-opening metathesis polymerization (ROMP) and reversible addition–fragmentation chain-transfer (RAFT) polymerization, using “grafting-to” and “grafting-through” approaches. The facile preparation of the PVA bottlebrushes was performed via selective hydrolysis of the acetate of the poly(vinyl acetate) (PVAc) side chains of the PVAc bottlebrush precursors. Ice-binding polymer side-chain density was shown to be crucial for nucleation activity, with less dense brushes resulting in colder nucleation than denser brushes. This bio-inspired approach provides a synthetic framework for probing heterogeneous ice nucleation and a route toward defined synthetic nucleators for biotechnological applications