Using Geographically Referenced Data on Environmental Exposures for Public Health Research: A Feasibility Study Based on the German Socio-Economic Panel Study (SOEP)

Background: In panel datasets information on environmental exposures is scarce. Thus, our goal was to probe the use of area-wide geographically referenced data for air pollution from an external data source in the analysis of physical health. Methods: The study population comprised SOEP respondents in 2004 merged with exposures for NO2, PM10 and O3 based on a multi-year reanalysis of the EURopean Air pollution Dispersion-Inverse Model (EURAD-IM). Apart from bivariate analyses with subjective air pollution we estimated cross-sectional multilevel regression models for physical health as assessed by the SF-12. Results: The variation of average exposure to NO2, PM10 and O3 was small with the interquartile range being less than 10µg/m3 for all pollutants. There was no correlation between subjective air pollution and average exposure to PM10 and O3, while there was a very small positive correlation between the first and NO2. Inclusion of objective air pollution in regression models did not improve the model fit. Conclusions: It is feasible to merge environmental exposures to a nationally representative panel study like the SOEP. However, in our study the spatial resolution of the specific air pollutants has been too little, yet.SOEP, Geographically Referenced Data, Feasibility Study, Air Pollution, EURAD-IM, Physical Health

Exposure in chemical nanotechnology

Exposures to ultrafine dust due to naturally emitted and incidentally generated nanoscale particles are already known. The exposure to specifically engineered nanomaterials is a topic of actual interest. Keeping in mind the special and heterogeneous spectrum of exposure, exposed individuals underwent detailed examinations in our institute and at their workplace. We also analysed the chemical nanotechnology work sites

A Jordan-like decomposition for linear relations in finite-dimensional spaces

A square matrix A has the usual Jordan canonical form that describes the structure of A via eigenvalues and the corresponding Jordan blocks. If A is a linear relation in a finite-dimensional linear space H (i.e., A is a linear subspace of H × H and can be considered as a multivalued linear operator), then there is a richer structure. In addition to the classical Jordan chains (interpreted in the Cartesian product H × H), there occur three more classes of chains: chains starting at zero (the chains for the eigenvalue infinity), chains starting at zero and also ending at zero (the singular chains), and chains with linearly independent entries (the shift chains). These four types of chains give rise to a direct sum decomposition (a Jordan-like decomposition) of the linear relation A. In this decomposition there is a completely singular part that has the extended complex plane as eigenvalues; a usual Jordan part that corresponds to the finite proper eigenvalues; a Jordan part that corresponds to the eigenvalue infinity; and a multishift, i.e., a part that has no eigenvalues at all. Furthermore, the Jordan-like decomposition exhibits a certain uniqueness, closing a gap in earlier results. The presentation is purely algebraic, only the structure of linear spaces is used. Moreover, the presentation has a uniform character: each of the above types is constructed via an appropriately chosen sequence of quotient spaces. The dimensions of the spaces are the Weyr characteristics, which uniquely determine the Jordan-like decomposition of the linear relation

(Nano-)Partikel und neue Materialien in der Zahnheilkunde

In der Zahnheilkunde beschäftigte Personen sind gegenüber zahlreichen, teils potentiell gesundheitsgefährdenden Arbeitsstoffen exponiert. Zunehmend kommen (neue) Materialien wie Zirkonium — auch in nanoskaligem Maßstab — zum Einsatz, wodurch sich wiederum neue Wirkprofile und Auswirkungen auf die Gesundheit der Beschäftigten ergeben können

Tätigkeitsparallele Diagnostik bei beruflicher Exposition gegenüber Nanopartikeln und neuen Materialien. — II

Eine Exposition gegenüber ultrafeinen Stäuben — zurückzuführen auf natürlich freigesetzte und unbeabsichtigt erzeugte nanoskalige Partikel — ist seit langem bekannt. Neu dagegen ist die Exposition gegenüber gezielt industriell synthetisierten Nanomaterialien. Vor dem Hintergrund eines solch speziellen und sehr heterogenen Expositionsspektrums erfolgte nach ausführlicher Individual-Diagnostik eine tätigkeitsparallele Untersuchung bei Beschäftigten in der chemischen Nanotechnologie

Klinische und diagnostische Befunde bei beruflicher Exposition gegenüber Nanopartikeln und neuen Materialien

Die Nanotechnologie gilt als Schlüsseltechnologie des 21. Jahrhunderts. Mit Nanomaterialien wurden jedoch nicht nur technologisch hoch interessante, vielfältig einsetzbare nanoskalige Produkte geschaffen, sondern auch eine neue Kategorie von potentiell toxischen Substanzen für Beschäftigte, Endverbraucher und Umwelt. Vor dem Hintergrund individueller Faktoren, potentieller Wirkprinzipien und adverser Gesundheitseffekte durch Nanomaterialien erfolgte die Konzeption eines vielschichtigen Diagnostik-Programms, welches einer Gruppe von Beschäftigten in der Nanotechnologie angeboten wurde

Observational implications of gamma-ray burst afterglow jet simulations and numerical light curve calculations

We discuss jet dynamics for narrow and wide gamma-ray burst (GRB) afterglow jets and the observational implications of numerical simulations of relativistic jets in two dimensions. We confirm earlier numerical results that sideways expansion of relativistic jets during the bulk of the afterglow emission phase is logarithmic in time and find that this also applies to narrow jets with half opening angle of 0.05 radians. As a result, afterglow jets remain highly nonspherical until after they have become nonrelativistic. Although sideways expansion steepens the afterglow light curve after the jet break, the jet edges becoming visible dominates the jet break, which means that the jet break is sensitive to the observer angle even for narrow jets. Failure to take the observer angle into account can lead to an overestimation of the jet energy by up to a factor 4. This weakens the challenge posed to the magneter energy limit by extreme events such as GRB090926A. Late time radio calorimetry based on a spherical nonrelativistic outflow model remains relevant when the observer is approximately on-axis and where differences of a few in flux level between the model and the simulation are acceptable. However, this does not imply sphericity of the outflow and therefore does not translate to high observer angles relevant to orphan afterglows. For more accurate calorimetry and in order to model significant late time features such as the rise of the counterjet, detailed jet simulations remain indispensable.Comment: 7 Figures. Replaced with accepted version. Significantly expanded, including additional discussion of time scale

Wie bekommen wir Investitionen in moderne Breitbandnetze?: Podiumsdiskussion mit Roland Berger, René Obermann, Lars-Hendrik Röller und Hans-Werner Sinn / moderiert von Roland Tichy

In der abschließenden Podiumsdiskussion, die sich noch einmal mit dem Themenbereich IKT-Infrastruktur befasst, diskutieren Roland Berger, René Obermann, Lars-Hendrik Röller, Hans-Werner Sinn und Roland Tichy, „wie wir Investitionen in moderne Breitbandnetze bekommen“. Dabei ging es vor allem um die Frage, ob und wie sich eine geänderte Regulierung als Konjunkturprogramm erweisen kann, wenn sie den derzeitigen Investitionsstau in der deutschen IKT-Netzinfrastruktur beheben kann. Vieles deutet darauf hin, dass der Staat durch entsprechende Rahmensetzungen private Zukunftsinvestitionen anregen kann, die seinen eigenen Haushalt schonen. Nach Ansicht der Podiumsteilnehmer erfordert der Ausbau der Breitbandnetze keine großen zusätzlichen Ausgaben durch die Bundesregierung, sondern eine „intelligente Regulierung, die die Investitionsaktivitäten der Telekommunikationsunternehmen stimuliert“. Dadurch könnten bei den Nutzern aus allen Wirtschaftsbereichen, gerade auch aus dem Mittelstand, wichtige Beschäftigungs- und Produktivitätssteigerungseffekte entstehen.Breitbandkommunikation, Investition, Institutionelle Infrastruktur, Deutschland

Modeling homogeneous ignition processes of clustering solid particle clouds in isotropic turbulence

The objective of this study is to numerically investigate the ignition and combustion of pulverized solid fuels in turbulent conditions and to assess different modeling strategies relevant to large-eddy simulations (LES). The investigations show that due to the high Stokes number of solid particles, they do not necessarily follow the flow. At Stokes numbers around unity, particle–turbulence interactions can lead to particle clustering and change the ignition behavior. According to observations, ignition is most likely to happen outside the formed clusters, where suitable thermo-chemical conditions exist. To study this behavior, direct numerical simulations (DNS) of reactive particles in turbulent conditions employing detailed kinetics for solid and gas phases were performed. Pulverized fuel combustion was modeled using the point-particle approximation to represent the dispersed phase in an Eulerian–Lagrangian framework. Isotropic turbulence was employed to investigate the influence of particle clustering on the ignition process. After investigating the physical aspects of the ignition process, the DNS dataset was used as a benchmark for evaluating the reduced-order flamelet models usually employed in LES of pulverized fuel combustion during the ignition process. The flamelet model performance in predicting the selected quantity of interest was compared to the DNS data. An error decomposition was performed using the optimal estimator concept. Finally, the prediction accuracy of presumed PDFs is evaluated by calculating the errors in predicting the quantity of interest using different PDFs compared to the predictions using the accurate sub-filter joint distribution of the DNS data.</p

Analysis of clinical and diagnostic findings during exposures in chemical nanotechnology

The rapid development of nanotechnology - the key technology of the 21th century - demands a consideration of risks and assessment of health effects during exposures to nanomaterials. Due to their high surface to volume ratio, nanoscaled materials exhibit exceptional physical and chemical properties when compared to larger particles of the same composition. Therefore toxicological informations of the bulk material should be carefully applied to nano particles. One of the most relevant uptake pathways is the inhalation of nanoscaled particles. Effects on the respiratory tract like inflammation, oxidative stress and pulmonary fibrosis, adverse effects on the cardiovascular and central nervous system are considered. In addition, nanotubes with their structure similar to asbestos-fibres may have a carcinogenic potential. Taking into consideration the various possible working mechanism of nanomaterials, an extensive diagnostic program was designed and offered to a collective of employees in chemical nanotechnology