Coronal and chromospheric physics

The Solar Maximum Mission support program is mentioned along with investigations of the solar corona, prominences, and chromosphere. The solar limb was studied using far infrared and submillimeter photometry. Stokes profiles obtained from sunspot observations were examined with a polarimetric technique

Relativising human rights

Standards-based measures of country human rights performance yields a performance ranking for countries that is “absolute” or reflects the current state of human rights performance without taking into account the relative social, political, or economic conditions within countries. While absolute ranking is useful, it can lead to perverse outcomes in other areas of work. This article provides an alternative method for ranking country human rights performance that takes into account an array of additional variables that are related to the protection of civil and political rights. The method involves creating a relative score to compare different measures of human rights performance over time and across different regions. This approach leads to a view of relative human rights performance that should be of interest to human rights scholars and practitioners

Coronal and chromospheric physics

Achievements and completed results are discussed for investigations covering solar activity during the solar maximum mission and the solar maximum year; other studies of solar activity and variability; infrared and submillimeter photometry; solar-related atomic physics; coronal and transition region studies; prominence research; chromospheric research in quiet and active regions; solar dynamics; eclipse studies; and polarimetry and magnetic field measurements. Contributions were also made in defining the photometric filterograph instrument for the solar optical telescope, designing the combined filter spectrograph, and in expressing the scientific aims and implementation of the solar corona diagnostic mission

Bosonic molecules in rotating traps

We present a variational many-body wave function for repelling bosons in rotating traps, focusing on rotational frequencies that do not lead to restriction to the lowest Landau level. This wave function incorporates correlations beyond the Gross-Pitaevskii (GP) mean field approximation, and it describes rotating boson molecules (RBMs) made of localized bosons that form polygonal-ring-like crystalline patterns in their intrinsic frame of reference. The RBMs exhibit characteristic periodic dependencies of the ground-state angular momenta on the number of bosons in the polygonal rings. For small numbers of neutral bosons, the RBM ground-state energies are found to be always lower than those of the corresponding GP solutions, in particular in the regime of GP vortex formation.Comment: To appear in Phys. Rev. Lett. LATEX, 5 pages with 5 figures. For related papers, see http://www.prism.gatech.edu/~ph274cy

Crystalline boson phases in harmonic traps: Beyond the Gross-Pitaevskii mean field

Strongly repelling bosons in two-dimensional harmonic traps are described through breaking of rotational symmetry at the Hartree-Fock level and subsequent symmetry restoration via projection techniques, thus incorporating correlations beyond the Gross-Pitaevskii (GP) solution. The bosons localize and form polygonal-ring-like crystalline patterns, both for a repulsive contact potential and a Coulomb interaction, as revealed via conditional-probability-distribution analysis. For neutral bosons, the total energy of the crystalline phase saturates in contrast to the GP solution, and its spatial extent becomes smaller than that of the GP condensate. For charged bosons, the total energy and dimensions approach the values of classical point-like charges in their equilibrium configuration.Comment: Published version. Typos corrected. REVTEX4; 5 pages with 3 PS figures. For related papers, see http://www.prism.gatech.edu/~ph274c

Modelling Sulphur Clusters for an Understanding of Ultramarine

Ultramarine pigments are aluminosilicate-based and contain sulphur-based chromophores. Self-consistent-field Hartree-Fock and Møller-Plesset second order perturbation theory were applied to determine the relative stability of S2, S2 –., S2 2–, and S3, S3 –., S3 2–. The singly charged species was found to be the most stable in both sets. The transition from green to blue ultramarine is thought to be the transformation of the doubly charged species to the singly charged species and is known to be exothermic. Modelling studies supported this hypothesis. The open,C2v, isomer was found to be the most stable for the S3 –. molecule, which is the blue chromophore in ultramarine. The closed, D3h, geometry represents a transition state. The S4 molecule is the most likely chromophore in ultramarine red; however the specific isomer is uncertain. Under the assumption that S4 was formed by a concerted reaction between S3 –. and S+., aWoodward-Hoffmann analysis of the molecular orbitals of S3 –. and S+. supported the formation of the puckered square S4, pyramidal S4, double triangle S4, and gauche S4 chain isomers. The gauche S4 chain is the most likely isomer in ultramarine red.Keywords: Ultramarine pigments, Woodward-Hoffmann analysis, modelling

Tensions in setting health care priorities for South Africa's children.

The new South African constitution commits the government to guarantee "basic health services "for every child under 18. Primary health care for pregnant women and children under six and elements of essential primary health care have received priority. At present, there is little analysis of the moral considerations involved in making choices about more advanced or costly health care which may, arguably, also be "basic". This paper illustrates some of the tensions in setting priorities for a just macroallocation of children's health care, given the realities of need and scarce resources, and the commitment to equality of basic opportunities. Originally published Journal of Medical Ethics, Vol. 24, No. 4, Aug 199

A bi-directional approach to comparing the modular structure of networks

Here we propose a new method to compare the modular structure of a pair of node-aligned networks. The majority of current methods, such as normalized mutual information, compare two node partitions derived from a community detection algorithm yet ignore the respective underlying network topologies. Addressing this gap, our method deploys a community detection quality function to assess the fit of each node partition with respect to the other network’s connectivity structure. Specifically, for two networks A and B, we project the node partition of B onto the connectivity structure of A. By evaluating the fit of B’s partition relative to A’s own partition on network A (using a standard quality function), we quantify how well network A describes the modular structure of B. Repeating this in the other direction, we obtain a two-dimensional distance measure, the bi-directional (BiDir) distance. The advantages of our methodology are three-fold. First, it is adaptable to a wide class of community detection algorithms that seek to optimize an objective function. Second, it takes into account the network structure, specifically the strength of the connections within and between communities, and can thus capture differences between networks with similar partitions but where one of them might have a more defined or robust community structure. Third, it can also identify cases in which dissimilar optimal partitions hide the fact that the underlying community structure of both networks is relatively similar. We illustrate our method for a variety of community detection algorithms, including multi-resolution approaches, and a range of both simulated and real world networks