900 research outputs found
Broadband: What do consumers want? Examining willingness-to-pay
A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and EconomicsRecently, fourth-generation mobile networks have gained traction. Those new mobile services offer speed comparable to existing fixed broadband access. This convergence in
speed of mobile and fixed broadband puts in question the need for consumers to be subscribed to two separate services for fixed and mobile access.
This study investigates the willingness-to-pay for mobile broadband as well as
consumers' willingness to give up speed for the flexibility of having their “regular”
internet access with them. A choice experiment is designed before analyzing the results from the experiments by estimating a random utility model and using the coefficients to analyze competitive strategies in the market. The analysis of the data shows that mobile capabilities seem to matter more to consumers than additional speed
Genetic and genomic analysis of polyploid Chrysanthemum hybrids with emphasis on shoot branching
[no abstract
Experimental probing of the anisotropy of the empty p states near the Fermi level in MgB2
We have studied the Boron K-edge in the superconductor MgB2 by electron
energy loss spectroscopy (EELS) and experimentally resolved the empty p states
at the Fermi level that have previously been observed within an energy window
of 0.8eV by soft x-ray absorption spectroscopy. Using angular resolved EELS, we
find that these states at the immediate edge onset have pxy character in
agreement with predictions from first-principle electronic structure
calculations.Comment: 15 pages, 5 figure
The Choice between MapMan and Gene Ontology for Automated Gene Function Prediction in Plant Science
Since the introduction of the Gene Ontology (GO), the analysis of high-throughput data has become tightly coupled with the use of ontologies to establish associations between knowledge and data in an automated fashion. Ontologies provide a systematic description of knowledge by a controlled vocabulary of defined structure in which ontological concepts are connected by pre-defined relationships. In plant science, MapMan and GO offer two alternatives for ontology-driven analyses. Unlike GO, initially developed to characterize microbial systems, MapMan was specifically designed to cover plant-specific pathways and processes. While the dependencies between concepts in MapMan are modeled as a tree, in GO these are captured in a directed acyclic graph. Therefore, the difference in ontologies may cause discrepancies in data reduction, visualization, and hypothesis generation. Here provide the first systematic comparative analysis of GO and MapMan for the case of the model plant species Arabidopsis thaliana (Arabidopsis) with respect to their structural properties and difference in distributions of information content. In addition, we investigate the effect of the two ontologies on the specificity and sensitivity of automated gene function prediction via the coupling of co-expression networks and the guilt-by-association principle. Automated gene function prediction is particularly needed for the model plant Arabidopsis in which only half of genes have been functionally annotated based on sequence similarity to known genes. The results highlight the need for structured representation of species-specific biological knowledge, and warrants caution in the design principles employed in future ontologies
Local boron doping quantification in homoepitaxial diamond structures
The capability of transmission electronmicroscopy (TEM) using the high angle annular dark fieldmode (HAADF,also labelled Z-contrast) to quantify boron concentration, in the high doping range between 1019cm−3 and 1021cm−3, is demonstrated. Thanks to the large relative variation of atomic number Z between carbon and boron, doping concentration maps and profiles are obtained with a nanometer-scale resolution. A novel numerical simulation procedure allows the boron concentration quantification and demonstrates the high sensitivity and
spatial resolution of the technique.4 page
The Electronic and Superconducting Properties of Oxygen-Ordered MgB2 compounds of the form Mg2B3Ox
Possible candidates for the Mg2B3Ox nanostructures observed in bulk of
polycrystalline MgB2 (Ref.1) have been studied using a combination of
Z-contrast imaging, electron energy loss spectroscopy (EELS) and
first-principles calculations. The electronic structures, phonon modes, and
electron phonon coupling parameters are calculated for two oxygen-ordered MgB2
compounds of composition Mg2B3O and Mg2B3O2, and compared with those of MgB2.
We find that the density of states for both Mg2B3Ox structures show very good
agreement with EELS, indicating that they are excellent candidates to explain
the observed coherent oxygen precipitates. Incorporation of oxygen reduces the
transition temperature and gives calculated TC values of 18.3 K and 1.6 K for
Mg2B3O and Mg2B3O2, respectively.Comment: Submitted to PR
The type of ploidy of chrysanthemum is not black or white: a comparison of a molecular approach to published cytological methods
Polyploidy is a widespread phenomenon among higher plants and a major factor shaping the structure and evolution of plant genomes. The important ornamental chrysanthemum (Chrysanthemum indicum hybrid) possesses a hexaploid genome with 54 chromosomes and was classified based on its evolutionary origin and cytological methods as an allopolyploid. However, it is questionable whether cytological methods are sufficient to determine the type of ploidy, and there are more informative methods available based on molecular marker analyses. Therefore, we collected segregation data for 406 dominant molecular marker alleles [327 amplified fragment length polymorphism (AFLPs), 65 single-strand conformation polymorphism (SSCPs) and 14 microsatellites (EST-SSRs)] in a biparental F1 population of 160 individuals. We analyzed these data for the characteristics that differ between allopolyploids and autopolyploids, including the segregation ratio of each marker, the ratio of single-dose (SD) to multi-dose (MD) markers, the ratio of SD markers in coupling to those in repulsion and the banding patterns of the SSRs. Whereas the analysis of the segregation ratio of each polymorphic marker indicated disomic (13 markers) as well as hexasomic (eight markers) inheritance, the ratio of SD markers in coupling to those in repulsion was 1:0, which is characteristic of autopolyploids. The observed ratio of SD to MD markers was 0.67:0.33 which is significantly different to the expected segregation for auto- and allohexaploids. Furthermore, the three EST-SSR alleles were inherited in all possible combinations and were not independent of each other, as expected for fixed heterozygosity in allopolyploids. Combining our results with published cytological data indicates that cultivated chrysanthemums should be classified as segmental allohexaploids.BMEL
- …