Ueber eine kolloide Theorie der Oberflächenspannung

Ohne Zusammenfassung Uebersetzt von Alexander Naumann (Leipzig).     

Efficient synthesis of (−)-(R)- and (+)-(S)-rolipram

A novel, efficient and protecting group free enantioselective synthetic approach of (?)-(R)-1 and (+)-(S)-rolipram 2 is described employing the organocatalyzed asymmetric Michael addition, Henry condensation, Wittig olefination and reductive lactamization reactions as key steps.     

Channel coordination with manufacturer��s return policies within a newsvendor framework

The saliency of returns in today’s business world is unquestionable, in such items as toys, Christmas decorations, books, seasonal/fashion items and the like. This is largely due to the high economic benefits prevalent in some industries today and to the increasing opportunities for resale in secondary and global markets. This paper attempts to model the profitability of returns policy in presence of a secondary market, to a profit-maximizing manufacturer in a newsvendor framework. The returns policy applies both for the unsold merchandise left at the end of the selling season and the items returned by the unsatisfied customers within the specified time period. With a returns policy, the manufacturer shares the risks of demand uncertainty, in turn assuaged by the availability of secondary market. The manufacturer’s decision is to arrive at an optimal wholesale price and the returns policy, based on the retailer’s reaction on that offer. The retailer in turn optimizes the retail price and the order quantity to meet a price-dependent uncertain demand. This set of optimal policies has then been contrasted to that obtained from maximizing the combined profit of the manufacturer and of the retailer. The key question in the comparison has been clearly answered. The total combined profit that coordinates the policies of both channels exceeds that of the sum of the profits obtained independently.     

Maintenance of residual activity of Bt toxin by using natural and synthetic dyes: a novel approach for sustainable mosquito vector control

Mosquito control protein from Bacillus thuringiensis gets inactivated with exposure to sunlight. To address this issue, the potential of synthetic and natural dye was investigated as sunlight protectants. Bt SV2 in absence of dyes when exposed to sunlight showed reduced effectiveness against the fourth instars of mosquito larvae. Whereas acriflavin, congo red and violacein were able to maintain 86.4%, 91.6% and 82.2% mosquito larvicidal efficacy of Bt SV2 against IVth instars larvae of Anopheles stephensi Meigen after exposure to sunlight. Similarly, beetroot dye, acriflavin, congo red and violacein maintained 98.4%, 97.1%, 90.8% and 70.7% larvicidal activities against Aedes aegypti Linnaeus after sunlight exposure. Prodigiosin was found to be the best photo-protectant by simultaneously protecting and enhancing Bt activity by 6.16% and 22.16% against A. stephensi and A. aegypti, respectively. Combination of dyes with Bt formulations can be a good strategy for mosquito control programmes in tropical and sub-tropical regions.     

Surface spin glass behavior in sol-gel derived La0.7Ca0.3MnO3 nanotubes

We report the fabrication of La(0.7)Ca(0.3)MnO(3) nanotubes (LCMONTs) with a diameter of about 200 nm, by a modified sol-gel method utilizing nanochannel alumina templates. High resolution transmission electron microscopy confirmed that the obtained LCMONTs are made up of nanoparticles (8-12 nm), which are randomly aligned in the wall of the nanotubes. The strong irreversibility between zero field cooling (ZFC) and field cooling (FC) magnetization curves as well as a cusplike peak in the ZFC curve gives strong support for surface spin glass behavior.