Spectral and radiometric requirements for the airborne thermal imaging spectrometer ARES

ARES (Airborne Reflective/Emissive Spectrometer) is an airborne imaging spectrometer for remote sensing of land surfaces covering the wavelength regions 0.45–2.45?µm and 8–13?µm with 160 channels. The instrument is being built by Integrated Spectronics, financed by DLR and GFZ, and will be available to the scientific community from 2005 on.

This contribution presents the design of the thermal spectrometer covering the 8–13?µm region with 32 channels of 150?nm bandwidth while a separate paper treats the instrument specifications in the solar reflective region. The spectro‐radiometric design is based on scientific requirements derived from application scenarios comprising vegetation, soils of different compositions, and mineral exploration. The corresponding emissivity spectra are input for a simulation model that calculates at‐sensor radiance spectra, resamples them with the channel‐specific response functions, adds different amounts of sensor noise to the signal, and performs a retrieval to get the corresponding noisy surface emissivity spectra. The results of the simulation study indicate that a spectral wavelength accuracy of 3?nm and a sensor noise equivalent temperature of 0.05–0.1?K are required for an accurate retrieval of emissivity spectra.     

The Acute Antiallodynic Effect of Tolperisone in Rat Neuropathic Pain and Evaluation of Its Mechanism of Action

Current treatment approaches to manage neuropathic pain have a slow onset and their use is largely hampered by side-effects, thus there is a significant need for finding new medications. Tolperisone, a centrally acting muscle relaxant with a favorable side effect profile, has been reported to affect ion channels, which are targets for current first-line medications in neuropathic pain. Our aim was to explore its antinociceptive potency in rats developing neuropathic pain evoked by partial sciatic nerve ligation and the mechanisms involved. Acute oral tolperisone restores both the decreased paw pressure threshold and the elevated glutamate level in cerebrospinal fluid in neuropathic rats. These effects were comparable to those of pregabalin, a first-line medication in neuropathy. Tolperisone also inhibits release of glutamate from rat brain synaptosomes primarily by blockade of voltage-dependent sodium channels, although inhibition of calcium channels may also be involved at higher concentrations. However, pregabalin fails to affect glutamate release under our present conditions, indicating a different mechanism of action. These results lay the foundation of the avenue for repurposing tolperisone as an analgesic drug to relieve neuropathic pain.     

Traditionally Processed Beverages in Africa: A Review of the Mycotoxin Occurrence Patterns and Exposure Assessment

African traditional beverages are widely consumed food‐grade liquids processed from single or mixed grains (mostly cereals) by simple food processing techniques, of which fermentation tops the list. These beverages are very diverse in composition and nutritional value and are specific to different cultures and countries. The grains from which home‐processed traditional beverages are made across Africa are often heavily contaminated with multiple mycotoxins due to poor agricultural, handling, and storage practices that characterize the region. In the literature, there are many reports on the spectrum and quantities of mycotoxins in crops utilized in traditional beverage processing, however, few studies have analyzed mycotoxins in the beverages themselves. The available reports on mycotoxins in African traditional beverages are mainly centered on the finished products with little information on the process chain (raw material to final product), fate of the different mycotoxins during processing, and exposure estimates for consumers. Regulations targeting these local beverages are not in place despite the heavy occurrence of mycotoxins in their raw materials and the high consumption levels of the products in many homes. This paper therefore comprehensively discusses for the 1st time the available data on the wide variety of African traditional beverages, the mycotoxins that contaminate the beverages and their raw materials, exposure estimates, and possible consequent effects. Mycotoxin control options and future directions for mycotoxin research in beverage production are also highlighted.     

The influence of the microstructure of high noble gold-platinum dental alloys on their corrosion and biocompatibility in vitro

The aim of this work was to compare the microstructures of two high noble experimental Au-Pt alloys with similar composition with their corrosion and biocompatibility in vitro. We showed that Au-Pt II alloy, composed of 87.3 wt.% Au, 9.9 wt.% Pt, 1.7 wt.% Zn and 0.5 wt.% Ir + Rh + In, although possessing better mechanical properties than the Au-Pt I alloy (86.9 wt.% Au, 10.4 wt.% Pt, 1.5 wt.% Zn and 0.5 wt.% Ir + Rh + In), exerted higher adverse effects on the viability of L929 cells and the suppression of rat thymocyte functions, such as proliferation activity, the production of Interleukin-2 (IL-2), expression of IL-2 receptor and activation — induced apoptosis after stimulation of the cells with Concanavalin-A. These results correlated with the higher release of Zn ions in the culture medium. As Zn²⁺, at the concentrations which were detected in the alloy’s culture media, showed a lesser cytotoxic effect than the Au-Pt conditioning media, we concluded that Zn is probably not the only element responsible for alloy cytotoxicity. Microstructural characterization of the alloys, performed by means of scanning electron microscopy in addition to energy dispersive X-ray and X-ray diffraction analyses, showed that Au-Pt I is a two-phase alloy containing a dominant Au-rich α₁ phase and a minor Pt-rich α₂ phase. On the other hand, the Au-Pt II alloy additionally contained three minor phases: AuZn3, Pt₃Zn and Au_1.4Zn_0.52. The highest content of Zn was identified in the Pt₃Zn phase. After conditioning, the Pt₃Zn and AuZn₃ phases disappeared, suggesting that they are predominantly responsible for Zn loss, lower corrosion stability and subsequent lower biocompatibility of the Au-Pt II alloy.     

A PROMETHEE-based approach to portfolio selection problems

In this paper, we study the use of PROMETHEE outranking methods for portfolio selection problems. Starting from a new formulation of the PROMETHEE V method, we develop several alternative approaches based on the concepts of boundary portfolios and c-optimal portfolios. The proposed methods are compared in an extensive computational study. Results of these experiments show that methods based on the concept of c-optimal portfolios provide a good approximation to the (often computationally untractable) PROMETHEE ranking of all portfolios, while requiring only small computational effort even for large problems. For smaller problems, a PROMETHEE ranking of all boundary portfolios can be performed and provides a close approximation of the total ranking.     

Gallium gradients in Cu(In,Ga)Se2 thin‐film solar cells

The gallium gradient in Cu(In,Ga)Se₂ (CIGS) layers, which forms during the two industrially relevant deposition routes, the sequential and co‐evaporation processes, plays a key role in the device performance of CIGS thin‐film modules. In this contribution, we present a comprehensive study on the formation, nature, and consequences of gallium gradients in CIGS solar cells. The formation of gallium gradients is analyzed in real time during a rapid selenization process by in situ X‐ray measurements. In addition, the gallium grading of a CIGS layer grown with an in‐line co‐evaporation process is analyzed by means of depth profiling with mass spectrometry. This gallium gradient of a real solar cell served as input data for device simulations. Depth‐dependent occurrence of lateral inhomogeneities on the µm scale in CIGS deposited by the co‐evaporation process was investigated by highly spatially resolved luminescence measurements on etched CIGS samples, which revealed a dependence of the optical bandgap, the quasi‐Fermi level splitting, transition levels, and the vertical gallium gradient. Transmission electron microscopy analyses of CIGS cross‐sections point to a difference in gallium content in the near surface region of neighboring grains. Migration barriers for a copper‐vacancy‐mediated indium and gallium diffusion in CuInSe₂ and CuGaSe₂ were calculated using density functional theory. The migration barrier for the In_Cu antisite in CuGaSe₂ is significantly lower compared with the Ga_Cu antisite in CuInSe₂, which is in accordance with the experimentally observed Ga gradients in CIGS layers grown by co‐evaporation and selenization processes. Copyright © 2014 John Wiley & Sons, Ltd.