Margins within margins?: voices Speaking through a study of the provision of an educational program for the children of one Australian show circuit

This paper examines the tactics used by the Showmen's Guild of Australasia in successfully lobbying for the development of a distance education program for their children. The Guild is considered to be a 'marginalized' group, meaning members have less access to wealth, power, and status. Since 1930, members of the Showmen's Guild and their families have traveled from town to town providing agricultural and equestrian shows. Despite the diversity of backgrounds and experiences among people connected with the show circuit, the Guild is highly organized and has been politically active. Informal sanctions have been effective in enforcing group discipline and in presenting the image of a single body of opinion. In addition, investment in sophisticated machinery and technology has resulted in show people having the financial resources to buy homes and have a political voice via more 'normalized channels'. Although members learn early that they are a marginalized group and are perceived as different from the mainstream, the group maintains close ties and often celebrates its difference. Implications for educational program development center on the goals of educational programs designed for disadvantaged groups, and the status of other marginalized groups and their efforts to contest their marginalized status. (LP

Topology of Cell-Aggregated Planar Graphs

We present new algorithm for growth of non-clustered planar graphs by aggregation of cells with given distribution of size and constraint of connectivity k=3 per node. The emergent graph structures are controlled by two parameters--chemical potential of the cell aggregation and the width of the cell size distribution. We compute several statistical properties of these graphs--fractal dimension of the perimeter, distribution of shortest paths between pairs of nodes and topological betweenness of nodes and links. We show how these topological properties depend on the control parameters of the aggregation process and discuss their relevance for the conduction of current in self-assembled nanopatterns.Comment: 8 pages, 5 figure

Transition-metal interactions in aluminum-rich intermetallics

The extension of the first-principles generalized pseudopotential theory (GPT) to transition-metal (TM) aluminides produces pair and many-body interactions that allow efficient calculations of total energies. In aluminum-rich systems treated at the pair-potential level, one practical limitation is a transition-metal over-binding that creates an unrealistic TM-TM attraction at short separations in the absence of balancing many-body contributions. Even with this limitation, the GPT pair potentials have been used effectively in total-energy calculations for Al-TM systems with TM atoms at separations greater than 4 AA. An additional potential term may be added for systems with shorter TM atom separations, formally folding repulsive contributions of the three- and higher-body interactions into the pair potentials, resulting in structure-dependent TM-TM potentials. Towards this end, we have performed numerical ab-initio total-energy calculations using VASP (Vienna Ab Initio Simulation Package) for an Al-Co-Ni compound in a particular quasicrystalline approximant structure. The results allow us to fit a short-ranged, many-body correction of the form a(r_0/r)^{b} to the GPT pair potentials for Co-Co, Co-Ni, and Ni-Ni interactions.Comment: 18 pages, 5 figures, submitted to PR

Anisotropic Assembly of Colloidal Nanoparticles: Exploiting Substrate Crystallinity

We show that the crystal structure of a substrate can be exploited to drive the anisotropic assembly of colloidal nanoparticles. Pentanethiol-passivated Au particles of approximately 2 nm diameter deposited from toluene onto hydrogen-passivated Si(111) surfaces form linear assemblies (rods) with a narrow width distribution. The rod orientations mirror the substrate symmetry, with a high degree of alignment along principal crystallographic axes of the Si(111) surface. There is a strong preference for anisotropic growth with rod widths substantially more tightly distributed than lengths. Entropic trapping of nanoparticles provides a plausible explanation for the formation of the anisotropic assemblies we observe

A risk-adjusted performance history of public and private market real estate investment, 1978-1997

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1999.Includes bibliographical references (leaves 51-54).Since the inception of the Real Estate Investment Trust ("REIT"), the relative efficiency of the public and private real estate markets has been the subject of debate. Consequently, a determination of the more efficient real estate investment vehicle will probably have a significant effect on the future flow of capital into all real estate assets. This thesis proposes to identify which real estate investment medium, public or private, has provided greater efficiency to its investors as measured by risk adjusted total return over the 20 year period from 1978-1997. The initial objective of this thesis was to create a publicly traded real estate equity index(the "Thesis index") for comparison to the existing National Association of Real Estate Investment Trusts ("NAREIT") equity index in an effort to replicate the returns of the latter. This equity Thesis index is an annual weighted compilation of the total returns of each existing equity REIT, as identified by a query of the Compustat database, for each given year from 1978 through 1997. Returns were calculated as of the calendar year end commencing in 1978 and continuing through calendar year end 1997. The core objective of this thesis was to ultimately compare the de-levered Thesis index to the existing National Council of Real Estate Investment Fiduciaries ("NCREIF") index in order to determine which index has provided a greater risk adjusted return over the time series in question. Given the disparities in the risk profiles of the underlying indices and the need to ensure a homogeneous comparison, adjustments to the Thesis index have been made in order to compensate for leverage in the REIT capital structure, for the presence of development risk in the current REIT asset base, and for the respective weight of each real estate asset class within the NCREIF index.by Mark P. Moriarty and Pennock J. Yeatman, IV.S.M

Mechano-chemical manipulation of Sn chains on Si(1 0 0) by NC-AFM

We investigate the atomic structure of Sn dimer chains grown on the Si(1 0 0) surface using non-contact atomic force microscopy (NC-AFM) at cryogenic temperatures. We find that similar to the native Si(1 0 0) dimer structure, the ground state of the Sn dimer structure is buckled at low temperature. At 5 K we show that the buckling state of the Sn dimers may be controllably, and reversibly, manipulated with atomic precision by close approach of the tip, without modification of the underlying substrate buckling structure. At intermediate cryogenic temperatures we observe changes in the configuration of the dimer chains in the region where the tip-sample interaction is very weak, suggesting that the energy barrier to transit between configurations is sufficiently small to be surmounted at 78 K

L1551NE - Discovery of a Binary Companion

L1551NE is a very young (class 0 or I) low-mass protostar located close to the well-studied L1551 IRS5. We present here evidence, from 1.3mm continuum interferometric observations at ~1'' resolution, for a binary companion to L1551NE. The companion, whose 1.3mm flux density is ~1/3 that of the primary component, is located 1.43'' (~230 A.U. at 160pc) to the southeast. The millimeterwave emission from the primary component may have been just barely resolved, with deconvolved size ~0.82"x0.70" (~131x112 A.U.). The companion emission was unresolved (<100 A.U.). The pair is embedded within a flattened circum-binary envelope of size ~5.4'' x 2.3'' (~860 x 370 A.U.). The masses of the three components (i.e. from the cicumstellar material of the primary star and its companion, and the envelope) are approximately 0.044, 0.014 and 0.023 Mo respectively.Comment: 8 pages, 1 figur