"Bridging the Gap" through Australian Cultural Astronomy

For more than 50,000 years, Indigenous Australians have incorporated celestial events into their oral traditions and used the motions of celestial bodies for navigation, time-keeping, food economics, and social structure. In this paper, we explore the ways in which Aboriginal people made careful observations of the sky, measurements of celestial bodies, and incorporated astronomical events into complex oral traditions by searching for written records of time-keeping using celestial bodies, the use of rising and setting stars as indicators of special events, recorded observations of variable stars, the solar cycle, and lunar phases (including ocean tides and eclipses) in oral tradition, as well as astronomical measurements of the equinox, solstice, and cardinal points.Comment: Proceedings of IAU Symposium 278, Oxford IX International Symposium on Archaeoastronomy, International Society for Archaeoastronomy & Astronomy in Culture (ISAAC), held in Lima, Peru, 5-9 January 2011. 9 pages, 4 images, 1 table (Accepted

The isodiametric problem with lattice-point constraints

In this paper, the isodiametric problem for centrally symmetric convex bodies in the Euclidean d-space R^d containing no interior non-zero point of a lattice L is studied. It is shown that the intersection of a suitable ball with the Dirichlet-Voronoi cell of 2L is extremal, i.e., it has minimum diameter among all bodies with the same volume. It is conjectured that these sets are the only extremal bodies, which is proved for all three dimensional and several prominent lattices.Comment: 12 pages, 4 figures, (v2) referee comments and suggestions incorporated, accepted in Monatshefte fuer Mathemati

Nature and evolution of the meteorite parent bodies: Evidence from petrology and metallurgy

The physical as well as chemical properties of the meteorite parent bodies are reviewed and it is concluded that many differentiated meteorites were likely formed in asteroidal-sized parents. A new model is developed for the formation of pallasites at the interface between an iron core and olivine mantle in differentiated bodies only about 10 km in diameter, which are later incorporated into a second generation of larger (100 km) parent bodies

High-temperature chemical processing on asteroids: An oxygen isotope perspective

From the introduction: Small planetary bodies accreted within 2.4 Myr of solar system formation [1]. The primitive materials (CAIs, chondrules, matrix) incorporated into these asteroids were altered by a variety of secondary processes, including aqueous alteration, shock metamorphism, thermal metamorphism and melting. Here we look primarily at the role played by thermal metamorphism and melting in altering the oxygen isotope systematics of asteroidal materials

Water/Icy Super-Earths: Giant Impacts and Maximum Water Content

Water-rich super-Earth exoplanets are expected to be common. We explore the effect of late giant impacts on the final bulk abundance of water in such planets. We present the results from smoothed particle hydrodynamics simulations of impacts between differentiated water(ice)-rock planets with masses between 0.5 and 5 M_Earth and projectile to target mass ratios from 1:1 to 1:4. We find that giant impacts between bodies of similar composition never decrease the bulk density of the target planet. If the commonly assumed maximum water fraction of 75wt% for bodies forming beyond the snow line is correct, giant impacts between similar composition bodies cannot serve as a mechanism for increasing the water fraction. Target planets either accrete materials in the same proportion, leaving the water fraction unchanged, or lose material from the water mantle, decreasing the water fraction. The criteria for catastrophic disruption of water-rock planets are similar to those found in previous work on super-Earths of terrestrial composition. Changes in bulk composition for giant impacts onto differentiated bodies of any composition (water-rock or rock-iron) are described by the same equations. These general laws can be incorporated into future N-body calculations of planet formation to track changes in composition from giant impacts.Comment: 9 pages, 4 figures, Accepted for publication in ApJ Letter

Determining hierarchy between conflicting treaties: are there vertical rules in the horizontal system?

Treaties are contractual instruments that may provide special rules of priority in case they conflict with other treaties. When a treaty does not provide such rules, however, priority is determined by the rules of the Vienna Convention on the Law of Treaties (VCLT) and/or general principles of law. This article argues that both the VCLT and general principles of law do not provide an adequate solution to treaty conflicts. It suggests that the solution to treaty conflicts rests in a value-oriented reading of international law and the norms incorporated in treaties. Norms represent values and values represent interests or benefits for which international society requires protection. Conflicts of treaty norms are, therefore, conflicts of values that courts and dispute settlement bodies resolve by ordering a hierarchy of competing interests and protecting the most important interests in a given context

Parallelization of chip-based fluorescence immuno-assays with quantum-dot labelled beads

This paper presents an optical concept for the read-out of a parallel, bead-based fluorescence immunoassay conducted on a lab-on-a-disk platform. The reusable part of the modular setup comprises a detection unit featuring a single LED as light source, two emission-filters, and a color CCD-camera as standard components together with a spinning drive as actuation unit. The miniaturized lab-on-a-disk is devised as a disposable. In the read-out process of the parallel assay, beads are first identified by the color of incorporated quantum dots (QDs). Next, the reaction-specific fluorescence signal is quantified with FluoSpheres-labeled detection anti-bodies. To enable a fast and automated read-out, suitable algorithms have been implemented in this work. Based on this concept, we successfully demonstrated a Hepatitis-A assay on our disk-based lab-on-a-chip