How to Buy a Continent: The Protocols of Indian Treaties as Developed by Benjamin Franklin and Other Members of the American Philosophical Society

In 1743, when Benjamin Franklin announced the formation of an American Philosophical Society for the Promotion of Useful Knowledge, it was important for the citizens of Pennsylvania to know more about their American Indian neighbors. Beyond a slice of land around Philadelphia, three quarters of the province were still occupied by the Delaware and several other Indian tribes, loosely gathered under the wing of an Indian confederacy known as the Six Nations. Relations with the Six Nations and their allies were being peacefully conducted in a series of so-called “Indian Treaties” that dealt with the fur trade, threats of war with France, settlement of grievances, and the purchase of land

Spatially resolved stis spectra of WR + OB binaries with colliding winds

We present spatially resolved spectra of the visual WR + OB massive binaries WR 86, WR 146, and WR 147, obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. The systems are classified as follows: WR 86 = WC 7 + BO III, WR 146 = WC 6 + O8 I-IIf, WR 147 = WN 8 + O5-7 I-II(f). Both WR 146 and WR 147 are known to have strong nonthermal radio emission arising in a wind-wind collision shock zone between the WR and OB components. We find that the spectra of their O companions show Hα profiles in emission, indicative of large mass-loss rates and consistent with the colliding-wind model. Our spectra indicate that the B component in WR 86 has a low mass-loss rate, which possibly explains the fact that WR 86, despite being a long-period WR + OB binary, was not found to be a strong nonthermal radio emitter. Because of the small mass-loss rate of the B-star component in WR 86, the wind collision region must be closer to the B star and smaller in effective area, hence generating smaller amounts of nonthermal radio emission. Absolute magnitudes for all the stars are estimated based on the spectral types of the components (based on the tables by Schmidt-Kaler for OB stars and van der Hucht for WR stars) and compared with actual, observed magnitude differences. While the derived luminosities for the WC 7 and BO III stars in WR 86 are consistent with the observed magnitude difference, we find a discrepancy of at least 1.5 mag between the observed luminosities of the components in each of WR 146 and WR 147 and the absolute magnitudes expected from their spectral types. In both cases, it looks as though either the WR components are about 2 mag too bright for their spectral types or that the O components are about 2 mag too faint. We discuss possible explanations for this apparent discrepancy.Facultad de Ciencias Astronómicas y Geofísica

Hubble Space Telescope Imaging of the WR 38/WR38a Cluster

We are conducting a high angular resolution imaging survey of Galactic Wolf-Rayet stars using the Wide Field and Planetary Camera 2 aboard the Hubble Space Telescope. We have found a small stellar cluster associated with the faint, close pair WR 38 and WR 38a. We present astrometric measurements and photometry in the wide-band F336W (U), F439W (B), and F555W (V) filter system for these cluster and nearby stars. We compare their colors and magnitudes with calibrated model results for reddened stars to identify seven probable main sequence members of the cluster. A least-squares fit of the colors and magnitudes of this set yields a cluster reddening of E(B-V) = 1.45 +/- 0.14 mag and a distance of 3.7^{+3.8}_{-1.2} kpc. We discuss the relationship of this cluster to other objects along the line of sight, and we argue that the distance probably lies in the range 5 - 8 kpc (but is not as great as 14.5 kpc distance recently advocated by Shorlin, Turner, & Pedreros). At a distance of 8 kpc, the cluster would reside in a dense region of the Carina spiral arm, close to a giant molecular cloud and the starburst cluster NGC 3603.Comment: Submitted to AJ, 24 pages, 3 figures Content is significantly change

A High Angular Resolution Survey of Massive Stars in Cygnus OB2: Results from the Hubble Space Telescope Fine Guidance Sensors

We present results of a high angular resolution survey of massive OB stars in the Cygnus OB2 association that we conducted with the Fine Guidance Sensor 1R (FGS1r) on the Hubble Space Telescope. FGS1r is able to resolve binary systems with a magnitude difference delta-V < 4 down to separations as small as 0.01 arcsec. The sample includes 58 of the brighter members of Cyg OB2, one of the closest examples of an environment containing a large number of very young and massive stars. We resolved binary companions for 12 targets and confirmed the triple nature of one other target, and we offer evidence of marginally resolved companions for two additional stars. We confirm the binary nature of 11 of these systems from complementary adaptive optics imaging observations. The overall binary frequency in our study is 22% to 26% corresponding to orbital periods ranging from 20 - 20,000 years. When combined with the known short-period spectroscopic binaries, the results supports the hypothesis that the binary fraction among massive stars is > 60%. One of the new discoveries is a companion to the hypergiant star MT 304 = Cyg OB2-12, and future measurements of orbital motion should provide mass estimates for this very luminous star.Comment: accepted for AJ, 84 pages, 61 figure

Interests in high-functioning autism are more intense, interfering, and idiosyncratic than those in neurotypical development

Although circumscribed interests are pathognomonic with autism, much about these interests remains unknown. Using the Interests Scale (IS), this study compares interests between 76 neurotypical (NT) individuals and 109 individuals with high-functioning autism spectrum disorder (HF-ASD) matched groupwise on age, IQ, and gender ratio. Participants and their parents/caregivers completed diagnostic measures (the Autism Diagnostic Interview—Revised and the Autism Diagnostic Observation Schedule; HF-ASD only), cognitive tests (Wechsler IQ Scales), and questionnaires (the Repetitive Behavior Scale—Revised, the Behavior Rating Inventory of Executive Function, and the Social Responsiveness Scale), in addition to the IS. Consistent with previous research, HF-ASD and NT individuals did not differ in number of interest areas, but the types of interests and intensity of those interests differed considerably. Using only the IS intensity score, 81% of individuals were correctly classified (NT or HF-ASD) in a logistic regression analysis. Among individuals with HF-ASD, Interests Scale scores were significantly related to Autism Diagnostic Observation Schedule, Behavior Rating Inventory of Executive Function, Repetitive Behavior Scale—Revised, and Social Responsiveness Scale scores, but they were not related to Autism Diagnostic Interview—Revised scores, IQ, gender, age, or psychotropic medication use. The type and intensity, but not the number, of interests distinguish high-functioning individuals with ASD from NT individuals

Spatially resolved stis spectra of WR + OB binaries with colliding winds

We present spatially resolved spectra of the visual WR + OB massive binaries WR 86, WR 146, and WR 147, obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. The systems are classified as follows: WR 86 = WC 7 + BO III, WR 146 = WC 6 + O8 I-IIf, WR 147 = WN 8 + O5-7 I-II(f). Both WR 146 and WR 147 are known to have strong nonthermal radio emission arising in a wind-wind collision shock zone between the WR and OB components. We find that the spectra of their O companions show Hα profiles in emission, indicative of large mass-loss rates and consistent with the colliding-wind model. Our spectra indicate that the B component in WR 86 has a low mass-loss rate, which possibly explains the fact that WR 86, despite being a long-period WR + OB binary, was not found to be a strong nonthermal radio emitter. Because of the small mass-loss rate of the B-star component in WR 86, the wind collision region must be closer to the B star and smaller in effective area, hence generating smaller amounts of nonthermal radio emission. Absolute magnitudes for all the stars are estimated based on the spectral types of the components (based on the tables by Schmidt-Kaler for OB stars and van der Hucht for WR stars) and compared with actual, observed magnitude differences. While the derived luminosities for the WC 7 and BO III stars in WR 86 are consistent with the observed magnitude difference, we find a discrepancy of at least 1.5 mag between the observed luminosities of the components in each of WR 146 and WR 147 and the absolute magnitudes expected from their spectral types. In both cases, it looks as though either the WR components are about 2 mag too bright for their spectral types or that the O components are about 2 mag too faint. We discuss possible explanations for this apparent discrepancy.Facultad de Ciencias Astronómicas y Geofísica

In vitro growth and differentiation of primary myoblasts on thiophene based conducting polymers

Polythiophenes are attractive candidate polymers for use in synthetic cell scaffolds as they are amenable to modification of functional groups as a means by which to increase biocompatibility. In the current study we analysed the physical properties and response of primary myoblasts to three thiophene polymers synthesized from either a basic bithiophene monomer or from one of two different thiophene monomers with alkoxy functional groups. In addition, the effect of the dopants pTS- and ClO4 - was investigated. In general, it was found that pTS- doped polymers were significantly smoother and tended to be more hydrophilic than their ClO 4 - doped counterparts, demonstrating that the choice of dopant significantly affects the polythiophene physical properties. These properties had a significant effect on the response of primary myoblasts to the polymer surfaces; LDH activity measured from cells harvested at 24 and 48 h post-seeding revealed significant differences between numbers of cells attaching to the different thiophene polymers, whilst all of the polymers equally supported cell doubling over the 48 h period. Differences in morphology were also observed, with reduced cell spreading observed on polymers with alkoxy groups. In addition, significant differences were seen in the polymers\u27 ability to support myoblast fusion. In general pTS- doped polymers were better able to support fusion than their ClO4 - doped counterparts. These studies demonstrate that modification of thiophene polymers can be used to promote specific cellular response (e.g. proliferation over differentiation) without the use of biological agents. 2013 The Royal Society of Chemistry

Spatially resolved STIS spectra of WR+OB binaries with colliding winds

We present spatially resolved spectra of the visual WR+OB massive binaries WR86, WR146, and WR147, obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. The systems are classified as follows: WR86 = WC7 + B0 III, WR146 = WC6 + O8 I-IIf, WR147 = WN8 + O5-7 I-II(f). Both WR146 and WR147 are known to have strong non-thermal radio emission arising in a wind-wind collision shock zone between the WR and OB components. We find that the spectra of their O companions show Halpha profiles in emission, indicative of large mass-loss rates, and consistent with the colliding-wind model. Our spectra indicate that the B component in WR86 has a low mass-loss rate, which possibly explains the fact that WR86, despite being a long period WR+OB binary, was not found to be a strong non-thermal radio emitter. Because of the small mass-loss rate of the B star component in WR86, the wind collision region must be closer to the B star and smaller in effective area, hence generating smaller amounts of non-thermal radio emission. Absolute magnitudes for all the stars are estimated based on the spectral types of the components (based on the tables by Schmidt-Kaler for OB stars, and van der Hucht for WR stars), and compared with actual, observed magnitude differences. While the derived luminosities for the WC7 and B0 III stars in WR86 are consistent with the observed magnitude difference, we find a discrepancy of at least 1.5 magnitudes between the observed luminosities of the components in each of WR146 and WR147 and the absolute magnitudes expected from their spectral types. In both cases, it looks as though either the WR components are about 2 magnitudes too bright for their spectral types, or that the O components are about 2 magnitudes too faint. We discuss possible explanations for this apparent discrepancy.Comment: Accepted for publication in the Astronomical Journa

(gamma,np) reactions in ¹²C , ⁶Li and ^3,4He

The emission of neutron-proton pairs is the most probable outcome of photon absorbtion in the energy region above the giant resonance at least up to the pion threshold, but little detailed information on the process has been obtained due to experimental difficulties. Two nucleon emission following photon absorbtion by a correlated pair is favoured compared to direct knockout of a single nucleon, which is suppressed by the large momentum mismatch between the ingoing photon and a single outgoing fast nucleon. Studies of the (gamma,np) process seek firstly to obtain a quantitative understanding of the photon interaction mechanism, and through this to open the door to investigations of nucleon correlations in nuclei [1], information about which is long sought but not readily obtainable