46 research outputs found
Dynamic of the populations of commercial used fish in (through offshore wind farms) changed ecosystem structure
In der hier vorgelegten Studie werden die Auswirkungen der geplanten Offshore -
Windfarmen in der deutschen Nordsee auf die beiden kommerziell stark genutzten Fischarten
Pleuronectes platessa und Gadus morhua untersucht. In dem entwickelten
individuenbasierten Modell FiWi wird der Einfluss des eingebrachten Hartsubstrates (Piles
ohne Kolkschutz) für den genehmigten Offshore - Windpark Butendiek simuliert.
Der Schwerpunkt der Simulationsauswertung liegt auf der mittleren Abundanz und dem
durchschnittlichen prozentualen Aufenthalt der Superindividuen von P. platessa und G.
morhua während ihres Lebens im Windpark.This study will investigate the effects of the planned offshore wind farms in the German
North Sea on two breeds of fish - Pleuronectes platessa [plaice] and Gadus morhua [Atlantic
cod] - both of which are very important commercially. In the developed individual-based
model called FiWi, the effect of the hard substrate installed (piles without scouring protection)
will be simulated over the timeframe of 25 years (planned service life) for the approved
Butendiek offshore wind farm. The analysis will focus on the average abundance and the
average percentage residence of super-individuals from P. platessa and G. morhua species
during their life in the wind farm
Report from the EPAA workshop: In vitro ADME in safety testing used by EPAA industry sectors
AbstractThere are now numerous in vitro and in silico ADME alternatives to in vivo assays but how do different industries incorporate them into their decision tree approaches for risk assessment, bearing in mind that the chemicals tested are intended for widely varying purposes? The extent of the use of animal tests is mainly driven by regulations or by the lack of a suitable in vitro model. Therefore, what considerations are needed for alternative models and how can they be improved so that they can be used as part of the risk assessment process? To address these issues, the European Partnership for Alternative Approaches to Animal Testing (EPAA) working group on prioritisation, promotion and implementation of the 3Rs research held a workshop in November, 2008 in Duesseldorf, Germany. Participants included different industry sectors such as pharmaceuticals, cosmetics, industrial- and agro-chemicals. This report describes the outcome of the discussions and recommendations (a) to reduce the number of animals used for determining the ADME properties of chemicals and (b) for considerations and actions regarding in vitro and in silico assays. These included: standardisation and promotion of in vitro assays so that they may become accepted by regulators; increased availability of industry in vivo kinetic data for a central database to increase the power of in silico predictions; expansion of the applicability domains of in vitro and in silico tools (which are not necessarily more applicable or even exclusive to one particular sector) and continued collaborations between regulators, academia and industry. A recommended immediate course of action was to establish an expert panel of users, developers and regulators to define the testing scope of models for different chemical classes. It was agreed by all participants that improvement and harmonization of alternative approaches is needed for all sectors and this will most effectively be achieved by stakeholders from different sectors sharing data
Re: Assessment of principal parabens used in cosmetics after their passage through human epidermisdermis layers ( ex vivo
Use of an acoustic wave sensor to follow lead absorption by porcine skin
A new acoustic wave sensor capable of detecting and quantifying lead is presented, and fully characterized in terms of sensitivity, selectivity, and linear calibration range. The sensor was used to quantify lead absorption by pig stratum corneum and to follow in real time, both the absorption and desorption of lead by the skin. Values of lead absorption of 29.6 mg Pb2+/g of stratum corneum were obtained. Lead in solution was also quantified by atomic absorption spectrometry (AAS). The results obtained by both methods, AAS and the sensor, were compared and no statistical differences in the accuracy and precision of the results were found.http://www.sciencedirect.com/science/article/B6THH-4P4NPG3-2/1/5b7ff13690528fc99df11246c971c26
The outermost stratum corneum layer is an effective barrier against dermal uptake of topically applied micronized titanium dioxide
In order to help clarify the controversially discussed dermal uptake properties of micronized titanium dioxide (TiO), we conducted extensive in vitro dermal absorption studies with 'Franz-type' diffusion cells on excised porcine skin. After biopsies and chemical fixation, the overall localization of TiO in the skin was analyzed by means of transmission electron microscopy (TEM). The lateral and vertical distribution of TiO within the stratum corneum (SC) was investigated by tape stripping and subsequent scanning electron microscopy (SEM) in combination with energy dispersive X-ray analysis (EDXA). TiO was found exclusively on the outermost SC layer. The surface deposit, as displayed by TEM, featured clearly distinguishable agglomerates as well as single particles with a characteristic cubic shape and a primary particle size of about 20-50 nm. Concurrently, SEM/EDXA micrographs first showed an even distribution of TiO on the skin surface. After 10-fold stripping, however, TiO was found to be localized only in the furrows and not on the partially removed ridges of the skin surface. SEM/EDXA micrographs of the adhesive tape strips revealed a characteristic pattern of stripped material and free regions. This pattern was an imprint of the skin's topography. Hence, tape stripping initially removed TiO and SC layers only from the ridges and not from the deeper furrows. Continued stripping increasingly yielded material from the deeper contours of the SC surface. TiO was found only in traces in the upper part of the follicle without any evidence of uptake into the follicular epithelium. This indicates that there is not any relevant penetration via the follicular route. We conclude that due to the microtopography of the skin, the strip number normally does not reflect the SC layer number. Accordingly, tape stripping results should always be interpreted with care, especially in the case of topically applied particles, as even higher numbers of subsequent strips may still sample material from the outermost SC layer of the deeper furrows, which could be interpreted falsely as penetrated material. Our results clearly demonstrate that TiO homogeneously and completely covers the outermost SC layer. It is neither delivered to the SC nor to the underlying skin layers when applied topically to porcine skin in vitro in the cosmetic vehicle used here. These findings underscore the safety of this micronized inorganic UV filter