Marine Shell Ear Disks from Protohistoric Caddo Sites on Stoots Creek, Hopkins County, Texas

In this article, we discuss three engraved marine shell ear disks from two protohistoric (ca. A.D. 1670-1700) Caddo sites on Stouts Creek in Hopkins County, Texas. These rather unique engraved marine shell disks have only been reported from three other archaeological sites in the entire southern Caddo area. Stouts Creek is a tributary to White Oak Creek. The drainage is situated in the modern Post Oak Savanna, at the far western edge of the distribution of Late Caddo Titus phase sites in Northeast Texas. The Stouts Creek marine shell ear disks we report on have been recovered from two different sites in the Stouts Creek valley. One came from a Caddo midden near the Culpepper site (41HP1), a protohistoric Caddo site excavated by The University of Texas in 1931. This particular marine shell disk has a central perforation and a 13.7 mm diameter engraved circle on its outer surface

The surface states of topological insulators - Dirac fermion in curved two dimensional spaces

The surface of a topological insulator is a closed two dimensional manifold. The surface states are described by the Dirac Hamiltonian in curved two dimensional spaces. For a slab-like sample with a magnetic field perpendicular to its top and bottom surfaces, there are chiral states delocalized on the four side faces. These "chiral sheets" carry both charge and spin currents. In strong magnetic fields the quantized charge Hall effect (\s_{xy}=(2n+1)e^2/h) will coexist with spin Hall effect.Comment: PRL accepted version, new information on thickness dependence adde

Aspirations for later life: a report of research carried out by the National Centre for Social Research on behalf of the Department for Work and Pensions (Research Report No 737)

This research report presents new survey findings on people’s aspirations for later life (that is, aged 60 onwards) in Great Britain. The survey sought to determine whether people hold aspirations for their later life and, if so, what these might be. In addition, it sought to provide an insight into what are the enablers and barriers to achieving these aspirations. Questions were asked of adults of all ages, not just those in middle and older age groups to explore when people start thinking about later life and how these attitudes change across the life cycle. This survey was carried out as part of the National Centre for Social Research Omnibus Survey. The sample was drawn from the Postcode Address File (PAF), commonly used in general population surveys. Face-to-face interviews were carried out in summer 2010. A total of 1,867 adults aged 16 years and over took part in the survey. However, it was assumed that respondents aged 45 to 65 years (i.e. those closer to retirement) would be most likely to have aspirations for later life, and so the number of respondents in this category was boosted, to allow more detailed analysis of their answers

Dust, Ice, and Gas in Time (DIGIT) Herschel Observations of GSS30-IRS1 in Ophiuchus

As a part of the "Dust, Ice, and Gas In Time" (DIGIT) key program on Herschel, we observed GSS30-IRS1, a Class I protostar located in Ophiuchus (d = 120 pc), with Herschel/Photodetector Array Camera and Spectrometer. More than 70 lines were detected within a wavelength range from 50 to 200 mu m, including CO, H2O, OH, and two atomic [O I] lines at 63 and 145 mu m. The [C II] line, known as a tracer of externally heated gas by the interstellar radiation field (ISRF), is also detected at 158 mu m. All lines, except [O I] and [C II], are detected only at the central spaxel of 9 ''.4 x 9 ''.4. The [O I] emissions are extended along a NE-SW orientation, and the [C II] line is detected over all spaxels, indicative of an external photodissociation region. The total [C II] intensity around GSS30 reveals that the far-ultraviolet radiation field is in the range of 3 to 20 G(0), where G(0) is in units of the Habing Field, 1.6 x 10(-3) erg cm(-2) s(-1). This enhanced external radiation field heats the envelope of GSS30-IRS1, causing the continuum emission to be extended, unlike the molecular emission. The best-fit continuum model of GSS30-IRS1 with the physical structure including flared disk, envelope, and outflow shows that the internal luminosity is 10 L-circle dot, and the region is externally heated by a radiation field enhanced by a factor of 130 compared to the standard local ISRF.NASANational Research Foundation of Korea (NRF) - Ministry of Education of the Korean government NRF-2012R1A1A2044689National Research Foundation (NRF) - Ministry of Education of KoreaAstronom

On the "Poisson Trick" and its Extensions for Fitting Multinomial Regression Models

This article is concerned with the fitting of multinomial regression models using the so-called "Poisson Trick". The work is motivated by Chen & Kuo (2001) and Malchow-M{\o}ller & Svarer (2003) which have been criticized for being computationally inefficient and sometimes producing nonsense results. We first discuss the case of independent data and offer a parsimonious fitting strategy when all covariates are categorical. We then propose a new approach for modelling correlated responses based on an extension of the Gamma-Poisson model, where the likelihood can be expressed in closed-form. The parameters are estimated via an Expectation/Conditional Maximization (ECM) algorithm, which can be implemented using functions for fitting generalized linear models readily available in standard statistical software packages. Compared to existing methods, our approach avoids the need to approximate the intractable integrals and thus the inference is exact with respect to the approximating Gamma-Poisson model. The proposed method is illustrated via a reanalysis of the yogurt data discussed by Chen & Kuo (2001)