Consumentenproducten: blootstellingschatting van kinderen

Guidance for child specific exposure assessment of non-food products The risk assessment of children can be substantially improved by refining the exposure assessment. Children's exposure to chemical compounds will differ according to behaviour, physiological function or exposure pattern during the use of chemical products. An exposure assessment specifically designed for children is therefore necessary. This report provides guidance for the exposure assessment of consumer products ("non-food"). Different exposure aspects of child-specific activities at different ages (0 to18 years) are outlined here. Furthermore, the report illustrates how children can be exposed to all the different product types within a specific group of chemicals, the biocides. In addition, the report provides information on how the models from the RIVM's ConsExpo 4.0 software package can be used to calculate exposure.Handreiking voor kinderspecifieke blootstellingschatting voor consumentenproducten. De risicoschatting voor kinderen kan aanzienlijk worden verbeterd door blootstellingscenario's specifiek voor kinderen op te stellen. Kinderen vertonen een ander gedragspatroon, zijn fysiologisch gezien verschillend van volwassen en worden tijdens gebruik van consumentenproducten op een andere wijze blootgesteld. Het huidige rapport biedt een handreiking voor het opstellen van kinderspecifieke scenario's voor de blootstelling aan consumentenproducten (voeding uitgezonderd). Het geeft een overzicht van een aantal kinderspecifieke activiteiten voor kinderen in verschillende leeftijdscategoriekn (0-18 jaar). Daarnaast wordt ingegaan op de blootstelling aan een diverse groep van chemische stoffen, de biociden. Ook wordt aangegeven welke modellen van het RIVM softwareprogramma ConsExpo 4.0 gebruikt kunnen worden voor de berekening van de blootstelling

Spontaneous baroreflex sensitivity in (pre)adolescents

Objective To present normal spontaneous baroreflex sensitivity (BRS) values and investigate the influence of posture, sex, age, pubertal stage, body mass index (BMI), , and physical activity level on BRS in (pre)adolescents. BRS is a sensitive measure of both sympathetic and parasympathetic cardiovascular regulation that may help detect early subclinical autonomic dysfunction. Design A cross-sectional cohort study in a large sample of 10-13-year-old Dutch (pre)adolescents from the general population. Methods Short-term spontaneous BRS was determined non-invasively by Portapres in both the supine and standing position. BRS was calculated by power spectral analysis using the discrete Fourier method (frequency band 0.07-0.14 Hz). Univariate statistical methods and multiple regression analyses were applied. Results BRS in a standing position was lower than in a supine position (9.0 +/- 4.9 versus 15.3 +/- 9.1 ms/mmHg; t = 27.8, P < 0.001). Girls had lower BRS values than boys in both postures (supine 14.3 +/- 8.7 versus 16.4 +/- 9.4 ms/mmHg, beta = 0.12, P < 0.001; standing 8.4 +/- 4.4 versus 9.5 +/- 5.4 ms/mmHg, beta = 0.08, P = 0.012), independent of age, pubertal stage, BMI, and physical activity. Lower limits (P2.5) for normal BRS values in supine and standing positions were for girls 3.6 and 2.2 ms/mmHg and for boys 3.9 and 2.5 ms/mmHg, respectively. BRS declined with age in the standing position (beta = -0.13, P < 0.001). In obese (pre)adolescents, BMI was negatively associated with BRS during standing (Kendall's tau = -0.26, P = 0.010). Conclusion The BRS of (pre)adolescents was negatively related to female sex, age, and obesity. A reduced BRS in obese (pre)adolescents might be a candidate predictor of future cardiovascular health, and therefore warrants further exploration

Towards a fully integrated indium-phosphide membrane on silicon photonics platform

In this work we present an integrated platform based on an InP membrane adhesively bonded to a silicon wafer. The platform allows for flexible design of wafer scale active and passive nanophotonic circuits. Advantages of this platform are the flexible fabrication process, large variety of integrated active and passive devices in one photonic layer, high index contrast of devices and therefore small footprint of complex circuits. We demonstrated several building blocks and devices, fabricated in the platform: semiconductor optical amplifiers, lasers and several passive devices, exploiting the high index contrast. Potential of the platform offers the integration of novel high speed devices using regrowth approach