Family Structure from Periodic Solutions of an Improved Gap Equation

Fermion mass models usually contain a horizontal symmetry and therefore fail to predict the exponential mass spectrum of the Standard Model in a natural way. In dynamical symmetry breaking there are different concepts to introduce a fermion mass spectrum, which automatically has the desired hierarchy. In constructing a specific model we show that in some modified gap equations periodic solutions with several fermion poles appear. The stability of these excitations and the application of this toy model are discussed. The mass ratios turn out to be approximately $e^\pi$ and $e^{2\pi}$. Thus the model explains the large ratios of fermion masses between successive generations in the Standard Model without introducing large or small numbers by hand.Comment: 19 pages, 8 figure

New mobile service development process

Mobile applications play an ever growing role in everybody’s life around our globe and the leading app stores currently offer more than 2 million different apps each for their users. It is well accepted that the usage context is much more important in the UI and UX design of these apps than when designing desktop applications. It is important to realize that a lot of these apps are part of a mobile service that defines their usage context and the UX of the mobile app is not only determined by the interaction with it but by the value creation of the whole service. We therefore propose in this paper a joint service and app design process that not only optimizes the user interaction with the mobile app but also the UX of the whole service in order to provide an optimal value proposition to the service customer of the mobile service

Solidification and wetting behaviour of SnAgCu solder alloyed by reactive metal organic flux

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.PURPOSE: The purpose of this paper is to develop a new alloying method for solders by using a metal organic modified flux in solder pastes. DESIGN/METHODOLOGY/APPROACH: This paper presents the impact of six metal organic compounds (Co, Fe, Al; stearate, oxalate, citrate) on the melting and solidification behaviour in comparison to the revealed microstructure. FINDINGS: It could be shown that Co and Al influence the supercooling whereas Fe exhibits no effect. Co reduces the supercooling of the cast of about 10 K and affects the nucleation. Al retards the solidification up to 185°C. Doping of the solder by flux containing metal organic compounds is successful and the alloying elements Co and Fe are found in the microstructure. RESEARCH LIMITATIONS/IMPLICATIONS: This paper provides a starting‐point for the new alloying method – so far only fluxes for solder pastes have been investigated. ORIGINALITY/VALUE: The reactive alloying method enables the use of new alloying elements for solder pastes in unmodified soldering processes.BMBF, 03X4504A, Flussmittel mit nanochemisch aktiven Metallverbindungen zur Stabilisierung von Weichloten durch Dispersion - NanoFlu

A genome-wide scan for genes under balancing selection in Drosophila melanogaster

BACKGROUND: In the history of population genetics balancing selection has been considered as an important evolutionary force, yet until today little is known about its abundance and its effect on patterns of genetic diversity. Several well-known examples of balancing selection have been reported from humans, mice, plants, and parasites. However, only very few systematic studies have been carried out to detect genes under balancing selection. We performed a genome scan in Drosophila melanogaster to find signatures of balancing selection in a derived (European) and an ancestral (African) population. We screened a total of 34 genomes searching for regions of high genetic diversity and an excess of SNPs with intermediate frequency. RESULTS: In total, we found 183 candidate genes: 141 in the European population and 45 in the African one, with only three genes shared between both populations. Most differences between both populations were observed on the X chromosome, though this might be partly due to false positives. Functionally, we find an overrepresentation of genes involved in neuronal development and circadian rhythm. Furthermore, some of the top genes we identified are involved in innate immunity. CONCLUSION: Our results revealed evidence of genes under balancing selection in European and African populations. More candidate genes have been found in the European population. They are involved in several different functions