254 research outputs found
Pollen grains induce a rapid and biphasic eczematous immune response in atopic eczema patients
Introduction: Eczematous reactions to type I allergy-inducing antigens are documented in a subgroup of patients with atopic eczema. Yet, the underlying immunological mechanisms are not well understood. Material and Methods: To delineate the effect of native pollen grains on human skin of healthy and atopic individuals we performed patch tests (atopy patch test with native pollen grains, PPT). Nickel patch tests (NPT) served as an established model of contact dermatitis. Skin site biopsies were taken 6 - 96 h after allergen application and investigated immunohistochemically. Results: Histology of positive patch tests showed an influx of mononuclear cells (predominantly CD4+, CD25+, CD45RO+). This influx was detected earlier in the PPT reaction than in the immune response to nickel. A biphasic cytokine response could be detected in the PPT: IL-5 dominated in the early, IFN-gamma in the late phase. The NPT was continuously dominated by IFN-gamma. Dendritic cell subpopulations imitated the earlier kinetics of the mononuclear infiltrate. Discussion: Thus, pollen grains induce eczematous reactions in susceptible individuals. This reaction appears clinically and immunohistochemically similar to the contact hypersensitivity reaction to nickel but follows a faster kinetic and a biphasic course: Th2 and IgE in the early (24 h) and Th1 predominance in the late (96 h) phase. Copyright (c) 2007 S. Karger AG, Basel
Die Petrographie keramischer Grabbeigaben und Steinwerkzeuge aus der Deltaebene des Mekong
In den vergangenen Jahren hat die Kommission fĂŒr ArchĂ€ologie AuĂereuropĂ€ischer Kulturen des Deutschen ArchĂ€ologischen Instituts Grabungsprojekte auf eisenzeitlichen GrĂ€berfeldern der PrĂ€-Funan-Kultur (500 v. bis 200 n. Chr.) in der Tiefl andebene des Mekong sowohl in Kambodscha (Prohear, Provinz Prey Veng) als auch in SĂŒdvietnam (GĂČ Ă ChĂča, Provinz Long An) durchgefĂŒhrt. Dabei wurden neben vielen Grabbeigaben aus Bronze, Eisen, Gold und Glas auch umfangreiche Keramik-Kollektionen und zahlreiche Gesteinsartefakte geborgen. Im unmittelbaren Umfeld der untersuchten FundplĂ€tze stehen keine Festgesteine an. Aus Mangel an Steinrohstoffen hat die Bevölkerung benachbarter eisenzeitlicher Siedlungen Werkzeuge wie Beile sogar aus Muschelschalen oder Schildkrötenpanzer hergestellt (Reinecke 2012: 241, Anm. 2). Eine Untersuchung beider Materialgruppen unter petrographischen Gesichtspunkten verspricht Einblicke in die Rohstoff-Beschaffung beider Orte. Da die beiden FundplĂ€tze Prohear und GĂČ Ă ChĂča nur 65 km Luftlinie voneinander entfernt liegen, ist es darĂŒber hinaus interessant, den Unterschieden oder Gemeinsamkeiten der Steinrohstoffe und des Tonmaterials beider Gemeinschaften nachzugehen (Abb. 1). Speziell bei der Keramik beider Fundstellen, die in Form, Farbe und Verzierung viele Ăbereinstimmungen zeigt, werden petrographische Untersuchungen auch mit zur AufklĂ€rung beitragen, ob beispielsweise zwei unterschiedliche âDorf-Töpfereienâ nach gleicher Tradition gearbeitet haben oder ob beide Gemeinschaften von einer oder mehreren zentralen Töpfereien beliefert worden sind
Auf der Suche nach dem passenden Rohstoff â Lithische Grabbeigaben und ihre Herkunft in der Deltaebene des Mekong
Die Deltaebene des Mekong in SĂŒdvietnam und Kambodscha wird von mĂ€chtigen alluvialen Sedimentschichten aufgebaut. Die Landschaft ist morphologisch flach und nur wenige reliktische Inselberge aus Festgesteinen erheben sich als HĂ€rtlinge aus der Landschaft (Abb. 1). FĂŒr die Bevölkerung vorgeschichtlicher Siedlungen stand also nur eine begrenzte Anzahl widerstandsfĂ€higer, fester Rohstoffe zur VerfĂŒgung, um Werkzeuge fĂŒr das alltĂ€gliche Leben wie zum Beispiel Beile, Mörser, StöĂel, Schab- und Schleifsteine herzustellen. Dennoch wurden bei archĂ€ologischen Grabungen auf eisenzeitlichen GrĂ€berfeldern der PrĂ€-Funan-Kultur (400 v. bis 100 n. Chr.) in den letzten Jahren neben reichhaltigen Grabbeigaben aus Bronze, Eisen, Gold und Glas sowie vielfĂ€ltigen Keramikkollektionen auch zahlreiche Gesteinsartefakte unterschiedlichster Genese geborgen (Reinecke et al. 2009). Dies deutet darauf hin, dass bereits fertige Werkzeuge oder entsprechende Rohstoffe aus dem ferneren Umland importiert wurden. Aufgrund des begrenzten Spektrums an natĂŒrlich vorkommenden FestgesteinsaufschlĂŒssen in der Tiefl andebene des Mekong stellt sich die Frage, ob anhand einer gezielten Beprobung der Gesteinsvorkommen eine Zuordnung der genutzten Gesteinswerkstoffe zu ihrer ursprĂŒnglichen Herkunftsregionen erfolgen kann. Um dieser Fragestellung nachzugehen, hat die Kommission fĂŒr ArchĂ€ologie AuĂereuropĂ€ischer Kulturen des Deutschen ArchĂ€ologischen Instituts im Jahr 2015 ein Forschungsstipendium vergeben. Ziel der Forschungsarbeiten ist es, mögliche Rohstoffquellen in der Deltaebene des Mekong zu identifi zieren und diese anhand geochemisch-petrographischer Untersuchungen mit den in Kambodscha (Prohear, Provinz Prey Veng) und SĂŒdvietnam (GĂČ Ă ChĂča, Provinz Long An) bei Grabungen des Deutschen ArchĂ€ologischen Instituts geborgenen Artefakten abzugleichen. Hierdurch soll die Rekonstruktionvon Handelsrouten sowohl fĂŒr die erforderlichen Rohstoffe als auch fĂŒr die bereits gefertigten Werkzeuge ermöglicht werden
Effect of an herbal extract of sideritis scardica and B-vitamins on cognitive performance under stress: A pilot study
Chronic stress can impair cognitive functions including learning and memory. The current study investigated the reduction of (mental) stress and improvement of stress tolerance in 64 healthy men and women after six weeks intake of a dietary supplement containing an extract of Sideritis scardica and selected B-vitamins. Mental performance and visual attention were measured by Trail-Making Test (TMT) and Colour-Word-Test (CWT)before/after an acute stress stimulus (noise, CW-Interference). TMT improved upon product intake. The CWT reaction time accelerated upon product intake in situations of CW-Congruence (overall) (p=0.014), CW-conflict (overall) (p=0.024), CW-conflict (with noise) (p=0.001), CW-Congruence (without noise) (p=0.004) and CW-conflict (without noise) (p=0.017).CWT-changes upon product intake, differentiated for noise and CW-interference, showed (i) a bisection of CW-interference-related impairment of the reaction time in the presence of noise from 27 ms to 13.5 ms, (ii) a bisection of noise-related impairment of the reaction time in the presence of CW-conflict from 34 ms to 17 ms, (iii) an improvement of the impairment of the reaction time due to combined stress (noise plus CW-conflict) by 14.5 ms from 66 ms to 51.5 ms, (iv) despite of the improvement of the reaction time, no increase of the error rate. Safety blood parameters and the reporting of no adverse events argue for the productâs safety. These results may be relevant for persons solving cognitive tasks under conflict and/or noise (e.g. open-plan offices or car-driving) andsupport that the tested product alleviatesstress-induced impairment of executive functioning (working memory, cognitive flexibility, controlled behavioural inhibition).Schaper & BrĂŒmmer GmbH & Co. KG, Salzgitter, German
Effect of an herbal extract of Sideritis scardica and B-vitamins on cognitive performance under stress: a pilot study
Chronic stress can impair cognitive functions including learning and memory. The current study investigated the reduction of (mental) stress and improvement of stress tolerance in 64 healthy men and women after six weeks intake of a dietary supplement containing an extract of Sideritis scardica and selected B-vitamins.Mental performance and visual attention were measured by Trail-Making Test (TMT) and Colour-Word-Test (CWT) before/after an acute stress stimulus (noise, CW-Interference).TMT improved upon product intake. The CWT reaction time accelerated upon product intake in situations of CW-Congruence (overall) (p=0.014), CW-conflict (overall) (p=0.024), CW-conflict (with noise) (p=0.001), CW-Congruence (without noise) (p=0.004) and CW-conflict (without noise) (p=0.017). CWT-changes upon product intake, differentiated for noise and CW-interference, showed (i) a bisection of CW-interference-related impairment of the reaction time in the presence of noise from 27 ms to 13.5 ms, (ii) a bisection of noise-related impairment of the reaction time in the presence of CW-conflict from 34 ms to 17 ms, (iii) an improvement of the impairment of the reaction time due to combined stress (noise plus CW-conflict) by 14.5 ms from 66 ms to 51.5 ms, (iv) despite of the improvement of the reaction time, no increase of the error rate. Safety blood parameters and the reporting of no adverse events argue for the productâs safety.These results may be relevant for persons solving cognitive tasks under conflict and/or noise (e.g. open-plan offices or car-driving) and support that the tested product alleviates stress-induced impairment of executive functioning (working memory, cognitive flexibility, controlled behavioural inhibition)
Entwicklung der Grundlagen fĂŒr eine Laboranlage zur kontinuierlichen Herstellung von PET-Recyclingpolyolen - Darstellung des Standes der Arbeiten im InnoRegio-Projekt
Die vorliegende Arbeit hat die Entwicklung der Grundlagen fĂŒr eine Anlage zum Ziel, mit der aus Polyethylenterephthalat (PET), insbesondere aus ProduktionsabfĂ€llen von PET-Verarbeitern, durch Umesterungen in Gegenwart von Diolen in einem kontinuierlichen Prozess aromatische Polyesterpolyole (APP) hergestellt werden können, die als Rohstoffe fĂŒr Polyurethane (PUR) verwendet werden
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Development and application of a backscatter lidar forward operator for quantitative validation of aerosol dispersion models and future data assimilation
A new backscatter lidar forward operator was developed which is based on the distinct calculation of the aerosolsâ backscatter and extinction properties. The forward operator was adapted to the COSMO-ART ash dispersion simulation of the Eyjafjallajökull eruption in 2010. While the particle number concentration was provided as a model output variable, the scattering properties of each individual particle type were determined by dedicated scattering calculations.
Sensitivity studies were performed to estimate the
uncertainties related to the assumed particle properties. Scattering calculations for several types of non-spherical particles required the usage of T-matrix routines. Due to the distinct calculation of the backscatter and extinction properties of the modelsâ volcanic ash size classes, the sensitivity studies could be made for each size class individually, which is not the case for forward models based on a fixed lidar ratio. Finally, the forward-modeled lidar profiles
have been compared to automated ceilometer lidar (ACL)
measurements both qualitatively and quantitatively while the attenuated backscatter coefficient was chosen as a suitable physical quantity. As the ACL measurements were not calibrated automatically, their calibration had to be performed using satellite lidar and ground-based Raman lidar measurements. A slight overestimation of the model-predicted volcanic ash number density was observed. Major requirements for future data assimilation of data from ACL have been identified, namely, the availability of calibrated lidar measurement data, a scattering database for atmospheric aerosols, a better representation and coverage of aerosols by the ash dispersion model, and more investigation in backscatter lidar forward operators which calculate the backscatter coefficient directly for each individual aerosol type. The introduced forward
operator offers the flexibility to be adapted to a multitude of model systems and measurement setups
Interessenstrukturen von Studierenden und damit verbundene Potentiale fĂŒr die Gewinnung von Lehramtsstudierenden
Der LehrkrĂ€ftemangel an beruflichen Schulen in gewerblich-technischen DomĂ€nen gab auch in der Vergangenheit immer wieder Anlass, durch die Umgestaltung der Ausbildungsangebote oder auch die Schaffung von Quereinstiegen zusĂ€tzliche Rekrutierungspotentiale zu schaffen (Nickolaus 1996; Ziegler 2004). Die dauerhafte und unterschiedliche Ausbildungsmodelle ĂŒbergreifende Rekrutierungsproblematik, verweist vermutlich auf dahinterliegende Grundprobleme, die unabhĂ€ngig von den jeweiligen Ausbildungsmodellen wirksam sind. Anlehnend an die Interessentheorie von Holland (1997) wird unterstellt, dass die fĂŒr TechnikpĂ€dagogikstudierenden notwendigen bzw. wĂŒnschenswerten Interessenprofile eher selten aufzufinden sind. Vor dem Hintergrund partieller fachlicher Ăberschneidungen der StudiengĂ€nge BerufspĂ€dagogik und der Ingenieurwissenschaften mit dem Studiengang TechnikpĂ€dagogik wird der Frage nachgegangen, in welcher Weise sich deren Interessenprofile unterscheiden und ob bzw. in welchem AusmaĂ, sich die StudiengĂ€nge der BerufspĂ€dagogik und der Ingenieurwissenschaften als Rekrutierungspotential fĂŒr die TechnikpĂ€dagogik eignen. Hierbei zeigt sich, dass bezogen auf die Interessenprofile, insbesondere Studierende ingenieurwissenschaftlicher FĂ€cher Schnittmengen mit Studierenden der TechnikpĂ€dagogik aufweisenSchlĂŒsselwörter: LehrkrĂ€fterekrutierung, TechnikpĂ€dagogik, berufliches Interesse, Berufswahltheorie_________The structure of vocational interests from students and the involved potential for the recruitment from students of lectureshipThe dearth of teaching staff at technical vocational schools led to the creation of additional recruitment potentials. Examples thereof are the reorganisation of the training programs, and the possibility of different entrance models (Nickolaus 1996; Ziegler 2004). The enduring recruitment difficulty which spans a wide range to the different kinds of training models underscores the ubiquity of this problem. In agreement with the theory of vocational choice of Holland (1997), it is imputed, that the necessary or desirable characteristic interests for vocational education teachers are lacking. Partial overlaps of the interest profiles of vocational education teachers with that of students of vocational education studies can also be assumed. Given this background, the question of how the interest profiles of the aforementioned fields of studies differ, and to what extent vocational education studies and engineering sciences offer a recruitment potential for engineering pedagogy, is being investigated. It was apparent that in particular students of engineering sciences had intersections in their interest profiles with students of engineering pedagogy.Keywords: recruitment of teachers, engineering pedagogy, vocational interest, theory of vocational choic
Observation of sensible and latent heat flux profiles with lidar
We present the first measurement of the sensible heat flux (H) profile in the convective boundary layer (CBL) derived from the covariance of collocated vertical-pointing temperature rotational Raman lidar and Doppler wind lidar measurements. The uncertainties of the H measurements due to instrumental noise and limited sampling are also derived and discussed. Simultaneous measurements of the latent heat flux profile (L) and other turbulent variables were obtained with the combination of water-vapor differential absorption lidar (WVDIAL) and Doppler lidar. The case study uses a measurement example from the HOPE (HD(CP) Observational Prototype Experiment) campaign, which took place in western Germany in 2013 and presents a cloud-free well-developed quasi-stationary CBL. The mean boundary layer height z was at 1230âm above ground level. The results show â as expected â positive values of H in the middle of the CBL. A maximum of (182±32)âWâm, with the second number for the noise uncertainty, is found at 0.5 z. At about 0.7 z, H changes sign to negative values above. The entrainment flux was (â62±27)âWâm. The mean sensible heat flux divergence in the observed part of the CBL above 0.3 z was â0.28âWâm, which corresponds to a warming of 0.83âKâh. The L profile shows a slight positive mean flux divergence of 0.12âWâm and an entrainment flux of (214±36)âWâm. The combination of H and L profiles in combination with variance and other turbulent parameters is very valuable for the evaluation of large-eddy simulation (LES) results and the further improvement and validation of turbulence parameterization schemes
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