Whispering Gallery Mode Resonator Stabilized Narrow Linewidth Fiber Loop Laser

We demonstrate a narrow line, fiber loop laser using Erbium-doped fiber as the gain material, stabilized by using a microsphere as a transmissive frequency selective element. Stable lasing with a linewidth of 170 kHz is observed, limited by the experimental spectral resolution. A linear increase in output power and a red-shift of the lasing mode were also observed with increasing pump power. Its potential application is also discussed

Sub-kHz lasing of a CaF_2 Whispering Gallery Mode Resonator Stabilized Fiber Ring Laser

We utilize a high quality calcium fluoride whispering-gallery-mode resonator to stabilize a simple erbium doped fiber ring laser with an emission frequency of 196 THz (wavelenght 1530 nm) to a linewidth below 650 Hz. This corresponds to a relative stability of 3.3 x 10^(-12) over 16 \mus. In order to characterize the linewidth we use two identical self-built lasers and a commercial laser to determine the individual lasing linewidth via the three-cornered hat method.Comment: 4 pages, 3 figure

Rux is a cyclin-dependent kinase inhibitor (CKI) specific for mitotic cyclin–Cdk complexes

AbstractBackground: Roughex (Rux) is a cell-cycle regulator that contributes to the establishment and maintenance of the G1 state in the fruit fly Drosophila. Genetic data show that Rux inhibits the S-phase function of the cyclin A (CycA)–cyclin-dependent kinase 1 (Cdk1) complex; in addition, it can prevent the mitotic functions of CycA and CycB when overexpressed. Rux has no homology to known Cdk inhibitors (CKIs), and the molecular mechanism of Rux function is not known.Results: Rux interacted with CycA and CycB in coprecipitation experiments. Expression of Rux caused nuclear translocation of CycA and CycB, and inhibited Cdk1 but not Cdk2 kinase activity. Cdk1 inhibition by Rux did not rely on inhibitory phosphorylation, disruption of cyclin–Cdk complex formation or changes in subcellular localization. Rux inhibited Cdk1 kinase in two ways: Rux prevented the activating phosphorylation on Cdk1 and also inhibited activated Cdk1 complexes. Surprisingly, Rux had a stimulating effect on CycA–Cdk1 activity when present in low concentrations.Conclusions: Rux fulfils all the criteria for a CKI. This is the first description in a multicellular organism of a CKI that specifically inhibits mitotic cyclin–Cdk complexes. This function of Rux is required for the G1 state and male meiosis and could also be involved in mitotic regulation, while the stimulating effect of Rux might assist in any S-phase function of CycA–Cdk1

Cost-Benefit Analysis for the Selection, Migration, and Operation of a Campus Management System

An increasing number of students, together with organizational and technological requirements, pose new challenges for universities. For these reasons, Campus Management Systems provide a solution for the necessary IS-support in student administration. In order to ensure cost-effectiveness, an extensive cost-utility analysis of the campus management systems under consideration is required. The process model illustrated here facilitates a ten-step cost-utility analysis for the selection, migration and operation of a campus management System. The process-oriented approach addresses the challenges posed by cost and benefit allocation. The subsequent ten steps, using the case analysis of two large German universities, show that the implementation of an integrated campus management system can lead to significant cost saving effects. The presented process model enables comparative calculations of differences with regard to the alternatives. The approach enables a comprehensive decision-support system for the selection of a university-specific and individually applicable campus management system

Discussion and Validation of a CRM System Selection Approach with Experts

Due to the high failure rate, costs, and long duration of CRM implementation projects, it is crucial to evaluate softwaresolutions before making an investment decision. A methodological approach is required to make these decisions moreeffectively and efficiently. In this paper, an approach to evaluating CRM software packages is proposed that is the result of aliterature review. In a second step, an initial applicability check of the approach is conducted. The intention is to verify thefeasibility of the proposed approach with CRM experts who have practical experience with the selection of different systems.An empirical study that is subdivided into qualitative expert interviews and a quantitative online survey is used for thisverification. The core results demonstrate that the approach is a valid method for evaluating CRM software applications

Visualizing Information on a Sphere

We describe a method for the visualization of information units on spherical domains which is employed in the banking industry for risk analysis, stock prediction and other tasks. The system is based on a quantification of the similarity of related objects that governs the parameters of a mass-spring system. Unlike existing approaches we initialize all information units onto the inner surface of two concentric spheres and attach them with springs to the outer sphere. Since the spring stiffnesses correspond to the computed similarity measures, the system converges into an energy minimum which reveals multidimensional relations and adjacencies in terms of spatial neighborhoods. Depending on the application scenario our approach supports different topological arrangements of related objects. In order to cope with large data sets we propose a blobby clustering mechanism that enables encapsulation of similar objects by implicit shapes. In addition, we implemented various interaction techniques allowing semantic analysis of the underlying data sets. Our prototype system IVORY is written in JAVA, and its versatility is illustrated by an example from financial service providers

Critical adsorption at chemically structured substrates

We consider binary liquid mixtures near their critical consolute points and exposed to geometrically flat but chemically structured substrates. The chemical contrast between the various substrate structures amounts to opposite local preferences for the two species of the binary liquid mixtures. Order parameters profiles are calculated for a chemical step, for a single chemical stripe, and for a periodic stripe pattern. The order parameter distributions exhibit frustration across the chemical steps which heals upon approaching the bulk. The corresponding spatial variation of the order parameter and its dependence on temperature are governed by universal scaling functions which we calculate within mean field theory. These scaling functions also determine the universal behavior of the excess adsorption relative to suitably chosen reference systems