Involvement of GPR17 in Neuronal Fibre Outgrowth

Characterization of new pharmacological targets is a promising approach in research of neurorepair mechanisms. The G protein-coupled receptor 17 (GPR17) has recently been proposed as an interesting pharmacological target, e.g., in neuroregenerative processes. Using the well-established ex vivo model of organotypic slice co-cultures of the mesocortical dopaminergic system (prefrontal cortex (PFC) and substantia nigra/ventral tegmental area (SN/VTA) complex), the influence of GPR17 ligands on neurite outgrowth from SN/VTA to the PFC was investigated. The growth-promoting effects of Montelukast (MTK; GPR17- and cysteinyl-leukotriene receptor antagonist), the glial cell line-derived neurotrophic factor (GDNF) and of two potent, selective GPR17 agonists (PSB-16484 and PSB-16282) were characterized. Treatment with MTK resulted in a significant increase in mean neurite density, comparable with the effects of GDNF. The combination of MTK and GPR17 agonist PSB-16484 significantly inhibited neuronal growth. qPCR studies revealed an MTK-induced elevated mRNA-expression of genes relevant for neuronal growth. Immunofluorescence labelling showed a marked expression of GPR17 on NG2-positive glia. Western blot and RT-qPCR analysis of untreated cultures suggest a time-dependent, injury-induced stimulation of GPR17. In conclusion, MTK was identified as a stimulator of neurite fibre outgrowth, mediating its effects through GPR17, highlighting GPR17 as an interesting therapeutic target in neuronal regeneration.     

Stray current-induced corrosion in cathodic protection installations of steel-reinforced concrete structures: FEM study of the critical parameters

A wide range of parameters was investigated by numerical calculations concerning their impact on DC stray current corrosion of reinforced concrete (RC) structures. A simplified model geometry was used to extract the relevant parameters and their interaction in terms of stray current-affected structures. This study mainly focuses on RC structures that are fitted with cathodic protection installations. The findings reveal a complex interaction between the investigated parameters. The possible relevance of further parameters, which is not the subject of this study, was emphasised.     

Möglichkeiten zur Vorausberechnung von Verweilzeitverteilungen

Possible Approaches to the Prediction of Residence Time Distributions Although the experimental determination of residence time distributions is based on a black-box method, the signal shape also permits certain conclusions to be drawn about the internal conditions. However, if it is to provide a sole basis for elucidating process steps in a plant this method is soon overtaxed. A deeper theoretical penetration of the pertinent transport processes opens up the way ahead. However, since residence time distributions are based on mass-oriented considerations, substantial advances in fluid mechanics, where location-based considerations predominate, have not led to improved predictive capability. Yet the computer power now available offers a variety of ways of calculating residence-time distributions for a known flow profile, thus permitting a step in the direction of better predictability of residence time distributions. This article presents utilisable methods and evaluates them with regard to their demands on time and effort and their predictive power. Problems arising in connection with the models are discussed.     

Benin 2025—Balancing Future Water Availability and Demand Using the WEAP ‘Water Evaluation and Planning’ System

In Benin, annual water availability per capita far exceeds the critical threshold of about 1,700 m³, but during the dry season, water scarcity occurs at the local scale. By modeling the water balance of the Ouémé–Bonou catchment with WEAP (Water Evaluation and Planning System), this study aimed at analyzing Benin’s future water situation under different scenarios of socio-economic development and climate change until 2025. The results show that the pressure on Benin’s water resources will increase, leading to greater competition for surface water. Furthermore, financial and technological constraints hinder a satisfactory development, and exploration of groundwater and reservoir resources. However, improvements are most needed, especially in rural areas. Decreasing inflows and groundwater recharge due to climate change aggravate this situation. Even though there are uncertainties and constraints concerning the model and input data, this study shows that the WEAP results offer a solid basis to assist planners in developing recommendations for future water resource management by revealing hot spots of action.     

Intercomparison exercise of high pressure gas flow test facilities within GERG

Ten of the main European gas Companies decided to carry out the second intercomparison exercise of high pressure test facilities within GERG (Groupe Européen de Recherches Gazières). The survey has compared the performances of 8 high pressure gas flow laboratories in the period autumn 1998–autumn 1999.

The aim was to check to what extent results obtained at the various laboratories are comparable and to reveal possible ways of improving the performances. Tests have been carried out using three transfer standard packages of three different diameters. The considered performance parameters have been: (1) agreement of results between laboratories, (2) short term stability and (3) day to day reproducibility of the reference flow.

The following main conclusions have been drawn:

• The majority of the laboratories involved in the intercomparison produced very accurate results. Despite the involvement of five independent traceability chains, 92.5% of the test results are within a band of ±0.25%.

• For most facilities the short term fluctuations are of the order of ±0.1%. Individual facilities may perform even better.

• This exercise allowed us to confirm the good results of the previous campaign and to identify some items to improve future intercomparisons.

Mirror or Molder? A Study of Media Coverage,Stock Prices,and Trading Volumes in Germany

This article investigates the short‐term relationship between media coverage, stock prices, and trading volumes of eight listed German companies. A content analysis of news reports about the selected companies and a secondary analysis of the daily changes in closing prices and the trading volumes of these companies were combined in a time‐series design. After ARIMA‐modeling each of them, the results suggest that media coverage rather reflects than shapes the development at stock exchanges from a short‐term perspective (2 months). There were almost no hints for a widespread media effect, that is, an impact on so many investors that it will result in a measurable change in stock prices or trading volumes. Finally, theoretical and methodological consequences for exploring widespread media effects are discussed.     

Determination of beam parameters and coherence properties of laser radiation by use of an extended Hartmann-Shack wave-front sensor

A combination of a Hartmann-Shack sensor and a standard far-field measurement on one single detector is proposed. The technique is fast and operates without movable parts, thus permitting a compact design. It is not only suited for characterization of the wave-front distribution but may also be considered for determination of the important parameters of beam width, beam divergence, and beam propagation ratio M2 of partially coherent laser beams. First results indicate that a fairly thorough beam characterization, including spatial coherence, propagation characteristics, and beam quality, can be achieved with this method.