Applying the Yule-Nielsen equation with negative n

The theory of halftone printing has attracted the attention of both industry and scientists for decades. The Yule-Nielsen equation has been used for color prediction for more than fifty years now, but apparently the tuning parameter n has been taken to be only larger than or equal to one. Our paper shows that the extension to the whole real axis is well defined in a mathematical sense. We fitted models to data from the ceramics tile printing sector (Rotocolor and Kerajet printing techniques) and found that using a negative n in almost all considered cases resulted in a better fit.     

Strong Attraction of the Parasitoid <Emphasis Type="Italic">Cotesia marginiventris</Emphasis> Towards Minor Volatile Compounds of Maize

Plants infested with herbivorous arthropods emit complex blends of volatile compounds, which are used by several natural enemies as foraging cues. Despite detailed knowledge on the composition and amount of the emitted volatiles in many plant-herbivore systems, it remains largely unknown which compounds are essential for the attraction of natural enemies. In this study, we used a combination of different fractionation methods and olfactometer bioassays in order to examine the attractiveness of different compositions of volatile blends to females of the parasitoid Cotesia marginiventris. In a first step, we passed a volatile blend emitted by Spodoptera littoralis infested maize seedlings over a silica-containing filter tube and subsequently desorbed the volatiles that were retained by the silica filter (silica extract). The volatiles that broke through the silica filter were collected on and subsequently desorbed from a SuperQ filter (breakthrough). The silica extract was highly attractive to the wasps, whereas the breakthrough volatiles were not attractive. The silica extract was even more attractive than the extract that contained all herbivore-induced maize volatiles. Subsequently, we fractioned the silica extract by preparative gas-chromatography (GC) and by separating more polar from less polar compounds. In general, C. marginiventris preferred polar over non-polar compounds, but several fractions were attractive to the wasp, including one that contained compounds emitted in quantities below the detection threshold of the GC analysis. These results imply that the attractiveness of the volatile blend emitted by Spodoptera-infested maize seedlings to C. marginiventris females is determined by a specific combination of attractive and repellent/masking compounds, including some that are emitted in very small amounts. Manipulating the emission of such minor compounds has the potential to greatly improve the attraction of certain parasitoids and enhance biological control of specific insect pests.     

Deutsche Nationalbibliothek 4. Erweiterungsbau in Leipzig – Besonderheiten bei der Unterfangung und der Bestandssicherung

Derzeit entsteht der 4. Erweiterungsbau der Deutschen Nationalbibliothek in Leipzig. Der neue Baukörper grenzt bereichsweise an die Bestandsgebäude und wurde 6 bis 8 m unterhalb der bestehenden Fundamente gegründet. Der setzungsempfindliche Baugrund infolge eines 4 m mächtigen Kohleflözes musste in der Planung besonders berücksichtigt werden. Um die Bestandsgebäude gegen Setzungen, Rissbildungen und Schiefstellungen zu schützen, wurden außergewöhnliche Sicherungsmaßnahmen realisiert: –·Zusammenspannen der Gebäude mittels Anordnung von Zugstäben –·Auskreuzung gefährdeter Bereiche durch Holz‐Fachwerkverbände –·Anwendung einer besonderen Technologie der HDI‐Unterfangung. Mit diesen Maßnahmen konnten ungleichmäßige Setzungen und Rissbildungen weitestgehend vermieden werden. The German National Library in Leipzig – 4^th extension – Special features of the underpinning and safety measures of inventory. At present the 4^th extension of the German National Library in Leipzig is under construction. The new building is near the existing buildings and was founded in 6 to 8 m below the existing foundations. The ground is liable to subsidence due to a 4 m thick coal seam. This had to be specially considered in the planning. To protect the existing buildings against settlements, cracking and misalignment extraordinary safety measures were implemented: –·tensioning arrangement of buildings by means of tension bars –·strengthening of vulnerable areas by timber trussed bond –·using a special technology of grouted underpinning With these measures, non‐uniform settlements and cracks could be largely avoided.     

Tunable photoemission from an excitonic antitrap

We study the influence of lithographically defined, electrostatic trap configurations on the photon emission from dipolar excitons in coupled quantum wells. The emission is surprisingly enhanced for an excitonic antitrap compared to a trap configuration, an effect more pronounced for a trap with smaller diameter. We explain the observations by the interplay between the exciton formation process, the lateral charge-carrier dynamics, and the dipole-dipole interactions between the excitons. Exploiting this interplay allows us to efficiently tune the excitonic emission energy with very small intensity variation.     

RebG- and RebM-catalyzed indolocarbazole diversification

Rebeccamycin and staurosporine represent two broad classes of indolocarbazole glycoside natural products with antitumor properties. Based upon previous sequence annotation and in vivo studies, rebG encodes for the rebeccamycin N-glucosyltransferase, and rebM for the requisite 4'-O-methyltransferase. In the current study, an efficient in vivo biotransformation system for RebG was established in both Streptomyces lividans and Escherichia coli. Bioconversion experiments revealed RebG to glucosylate a set of indolocarbazole surrogates, the products of which could be further modified by in vitro RebM-catalyzed 4'-O-methylation. Both RebG and RebM displayed substrate promiscuity, and evidence for a remarkable lack of RebG regioselectivity in the presence of asymmetric substrates is also provided. In the context of the created indolocarbazole analogues, cytotoxicity assays also highlight the importance of 4'-O-methylation for their biological activity.     

Effort, co-operation and co-ordination in an open source software project: GNOME

Abstract This paper presents results from research into open source projects from a software engineering perspective. The research methodology employed relies on public data retrieved from the CVS repository of the GNOME project and relevant discussion groups. This methodology is described, and results concerning the special characteristics of open source software development are given. These data are used for a first approach to estimating the total effort to be expended.     

Automated benchmark network diversification for realistic attack simulation with application to moving target defense

International Journal of Information Security - With numbers of exploitable vulnerabilities and attacks on networks constantly increasing, it is important to employ defensive techniques to protect...     

Transition metals to sulfur binding energies relationship to catalytic activities in HDS: back to Sabatier with first principle calculations

We have undertaken systematic calculations of transition metal sulfides bulk crystal structures, electronic and energetic properties at the first principles level (DFT, GGA, PW-USPP, PBC, implemented in the Vienna Ab initio Simulation Package, VASP). Relaxed cell parameters and ionic positions showed an excellent agreement with the experimental values. Computed and experimental cohesive energies agreed within 3%. We re-defined the metal–sulfur (M–S) bond strength as the cohesive energy per metal–sulfur bond: we show that all experimental HDS activities (Pecoraro and Chianelli, 1981) fit nicely on a single volcano master curve when plotted against this simple energetic parameter. Metallic (i.e. zero gap) ionic sulfides consistently exhibit the weakest M–S bonds and semi-conductor iono-covalent sulfides the strongest. However, the Sabatier principle suggests a simple kinetic interpretation of this master curve. This new interpretation also accounts for the well known synergetic effects in mixed sulfides and therefore opens new prospects for exploratory applied research.     

Spin coating of Blu-Ray disks: modeling,experiments, limitations,and manipulation

A major challenge in the production of Blu-Ray Disks (BDs) is making the cover layer over the information area. The layer has to be both thick enough to protect the information and even enough for the information to be read through it optically. Furthermore, it is preferred not to cover the hole in the center of the disk. Spin coating is a candidate method for the production of these layers in a rapid reproduction process. When dispensing is performed off-center (in order not to cover the hole), a new complication appears, namely the formation of a slope toward the inner rim of the liquid film. Here, fundamental limitations for achieving even films in this system and ways to overcome the difficulties by manipulation of the process are studied. A mathematical model for this particular case of spin coating is obtained and validated by comparison with experiments made in industrial equipment aiming at producing BDs. The model agrees well with the experimental data. The model is then used to show that cover layers that fulfil the Blu-Ray specification are very difficult to produce with the spin-coating technique. Manipulation by inline curing and surface shear is added to the model and the results show that it is considerably easier to meet the BD specification when utilizing the manipulation.