28 research outputs found
Cross-sectional associations between air pollution and chronic bronchitis: an ESCAPE meta-analysis across five cohorts
BACKGROUND: This study aimed to assess associations of outdoor air pollution on prevalence of chronic bronchitis symptoms in adults in five cohort studies (Asthma-E3N, ECRHS, NSHD, SALIA, SAPALDIA) participating in the European Study of Cohorts for Air Pollution Effects (ESCAPE) project. METHODS: Annual average particulate matter (PM10, PM2.5, PMabsorbance, PMcoarse), NO2, nitrogen oxides (NOx) and road traffic measures modelled from ESCAPE measurement campaigns 2008-2011 were assigned to home address at most recent assessments (1998-2011). Symptoms examined were chronic bronchitis (cough and phlegm for ≥3â
months of the year for ≥2â
years), chronic cough (with/without phlegm) and chronic phlegm (with/without cough). Cohort-specific cross-sectional multivariable logistic regression analyses were conducted using common confounder sets (age, sex, smoking, interview season, education), followed by meta-analysis. RESULTS: 15â
279 and 10â
537 participants respectively were included in the main NO2 and PM analyses at assessments in 1998-2011. Overall, there were no statistically significant associations with any air pollutant or traffic exposure. Sensitivity analyses including in asthmatics only, females only or using back-extrapolated NO2 and PM10 for assessments in 1985-2002 (ECRHS, NSHD, SALIA, SAPALDIA) did not alter conclusions. In never-smokers, all associations were positive, but reached statistical significance only for chronic phlegm with PMcoarse OR 1.31 (1.05 to 1.64) per 5â
µg/m(3) increase and PM10 with similar effect size. Sensitivity analyses of older cohorts showed increased risk of chronic cough with PM2.5abs (black carbon) exposures. CONCLUSIONS: Results do not show consistent associations between chronic bronchitis symptoms and current traffic-related air pollution in adult European populations
Constitutive modelling of skin ageing
The objective of this chapter is to review the main biomechanical and structural aspects associated with both intrinsic and extrinsic skin ageing, and to present potential research avenues to account for these effects in mathematical and computational models of the skin. This will be illustrated through recent work of the authors which provides a basis to those interested in developing mechanistic constitutive models capturing the mechanobiology of skin across the life course
Frequency stabilisation of Q-switched Nd:YAG oscillators for airborne and spaceborne LIDAR systems
Lidar Systems for the measurement of three-dimensional wind or cloud and aerosol formations in the earth atmosphere require highly stable pulsed single frequency laser systems with a narrow line width. The lasers for ESAs ADM-Aeolus and EarthCARE missions require frequency stabilities of 4 and 10 MHz rms at a wavelength of 355 nm and a line width below 50 MHz at 30 ns pulse duration[1]. Transferred to the fundamental wavelength of the laser systems the stability requirement is 1.3 and 3.3 MHz, respectively. In comparison to ground based lidar systems the vibrational load on the laser system is much higher in airborne and spaceborne systems, especially at high frequencies of some hundred Hertz or even some kHz. Suitable frequency stabilisation methods have therefore to be able to suppress these vibrations sufficiently. The often used Pulse-Build-up method is not suitable, due to its very limited capability to suppress vibration frequencies of the order of the pulse repetition frequency. In this study the performance of three frequency stabilisation methods in principle capable to meet the requirements, the cavity dither method, the modified Pound-Drever-Hall method and a modified Ramp-Fire method - named Ramp-Delay- Fire - is theoretically and experimentally investigated and compared. The investigation is performed on highly efficient, passively cooled, diode end-pumped q-switched Nd:YAG oscillators, which are breadboard versions of the A2D (ADM-Aeolus) and possible ATLAS (EarthCARE) oscillators. They deliver diffraction limited output pulses with up to 12 mJ pulse energy at a pulse duration of 30 ns and 100 Hz pulse repetition rate
Tropospheric ozone and skin aging: Results from two German cohort studies
During the last two decades, it has been well established that a short-term exposure to ozone (O3) elicits an oxidative stress response in human and mouse skin, which leads to aberrant transcriptional expression of genes consistent with increased skin aging. Whether a long-term exposure to ambient O3 is associated with any skin aging traits, has remained unclear. We addressed this question in two elderly German cohorts: the SALIA study (806 women aged 66â79âŻyears), and the BASE-II study (1207 men and women aged 60â84âŻyears). Five-year mean residential exposure to O3 was modeled as the number of days with maximum daily 8-h mean O3 concentrations â„120âŻÎŒg/m3 per year in the wider neighborhood (5-digit postcode) of a participant's residence. Extrinsic (environmentally induced) skin aging traits â coarse wrinkles and pigment spots (lentigines) on the face â were assessed by means of SCINEXAâą, a validated visual score previously shown to be well suited to measure extrinsic facial skin aging in cohort studies. We observed positive associations of O3 exceedances with coarse wrinkles in the face, but not with pigment spots. These associations were present in each cohort as well as in the combined sample of both cohorts. They were independent of chronic ultraviolet radiation exposure as the most obvious confounder, and also of co-pollutants such as particulate matter and nitrogen dioxide. Thus, long-term exposure to elevated concentrations of tropospheric O3 appears to contribute to skin aging