Flexible correction processes in social judgment: implications for persuasion

Journal ArticleTwo experiments were conducted to examine correction for perceived bias in persuasion situations. Study 1 showed that, although a manipulation of source likability had an impact on attitudes when no instruction to remove bias was present, when people were asked to remove any bias from their judgments, the effect of the source likability manipulation disappeared. The fact that the correction instruction did not increase the impact of an argument quality manipulation on attitudes suggested that effort aimed at correction is conceptually distinct from effort aimed at processing a message in general. Study 2 showed that a correction for source likability took place under low elaboration conditions--where a manipulation of source likability had an impact when no correction instructions were provided, and under high elaboration conditions--where a manipulation of source likability had no impact when no correction instructions were provided. In the high elaboration conditions, correcting for an impact that was not actually present led a dislikable source to be more influential than a likable source

X-Ray Emission from M32: X-Ray Binaries or a micro-AGN?

We have analysed archival {\it ROSAT} PSPC data for M32 in order to study the x-ray emission from this nearest elliptical galaxy. We fit spectra from three long exposures with Raymond-Smith, thermal bremsstrahlung, and power-law models. All models give excellent fits. The thermal fits have kT$\approx$4 keV, the Raymond-Smith iron abundance is $0.4^{+0.7}_{-0.3}$ Solar, the power-law fit has $\alpha$=1.6$\pm$0.1, and all fits have $N_H$ consistent with the Galactic column. The source is centered on M32 to an accuracy of 9$''$, and unresolved at 27$''$ FWHM ($\sim$90 pc). M32 is x-ray variable by a factor of 3--5 on timescales of a decade down to minutes, with evidence for a possible period of $\sim$1.3 days. There are two plausible interpretations for these results: 1) Emission due to low-mass x-ray binaries; 2) Emission due to accretion onto a massive central black hole. Both of these possibilities are supported by arguments based on previous studies of M32 and other old stellar systems; the {\it ROSAT} PSPC data do not allow us to unambiguously choose between them. Observations with the {\it ROSAT} HRI and with {\it ASCA} are required to determine which of these two very different physical models is correct.Comment: 9 pages, 5 PostScript figures, uses AASTeX style files, Accepted for publication in Astrophysical Journal Letter

Spectral properties of the X-ray binary pulsar LMC X-4 during different intensity states

We present spectral variations of the binary X-ray pulsar LMC X-4 observed with the RXTE/PCA during different phases of its 30.5 day long third period. Only out of eclipse data were used for this study. The 3-25 keV spectrum, modeled with high energy cut-off power-law and iron line emission is found to show strong dependence on the intensity state. Correlations between the Fe line emission flux and different parameters of the continuum are presented here.Comment: 4 pages, 4 figure

Stratigraphy and structure of the Horton Group, Lochaber-Mulgrave area, northern mainland Nova Scotia

The Lochaber-Mulgrave area of northern mainland Nova Scotia is underlain by rocks of the Late Devonian - Early Carboniferous Horton Group, in faulted contact with older Devonian and Silurian rocks to the south and west, and younger Carboniferous rocks to the north and east. The Horton Group is divided into (from oldest to youngest) the Clam Harbour River, Tracadie Road, Caledonia Mills, and Steep Creek formations, with a total thickness of at least 4000 m. These units were deposited in a variety of braided fluvial and shallow to deep lacustrine environments, and show lithological and stratigraphic similarities to the Horton Group elsewhere in Nova Scotia. Sparse palaeonto-logical data from macrofossils and spores indicate an age range from Famennian to late Tournaisian. Compared to elsewhere in Nova Scotia, the Horton Group in the Lochaber-Mulgrave area is more deformed and metamorphosed, especially in the southern part of the area near the Roman Valley Fault. The time of regional deformation and meta-morphism is constrained to ca. 340– 335 Ma by whole-rock 40Ar/39Ar dating of slate in the Clam Harbour River and Tracadie Road formations. Regional deformation and metamorphism may have resulted from burial by older rocks of the Guysborough block, thrust over the Horton Group in the Lochaber-Mulgrave area from the south as a result of transpression at a restraining bend along the Chedabucto-Roman Valley fault system during juxtaposition of the Avalon and Meguma terranes. RÉSUMÉ Le secteur de Lochaber-Mulgrave dans le nord de l'intérieur de la Nouvelle-Écosse repose sur des roches du groupe du Dévonien tardif au Carbonifère précoce de Horton, en contact faillé avec des roches du Dévonien et du Silurien au sud et à l'ouest, et avec des roches carbonifères au nord et à l'est. Le groupe de Horton se subdivise en (de la plus ancienne à la plus récente) formations de Clam Harbour River, de Tracadie Road, de Caledonia Mills et de Steep Creek, d'une épaisseur totale d'au moins 4 000 mètres. Ces unités se sont déposées au sein de divers environnements lacustres allant de peu profonds à profonds et d'environnements fluviaux anastomosés; elles présentent des similarités lithologiques et stratigraphiques avec le groupe de Horton ailleurs en Nouvelle-Écosse. Des données paléontologiques éparses tirées de macrofossiles et de spores révèlent une fourchette d'âges du Famennien au Tournaisien tardif. Comparativement aux autres régions de la Nouvelle-Écosse, le groupe de Horton dans le secteur de Lochaber-Mulgrave est plus déformé et métamorphisé, en particulier dans la partie méridionale du secteur, près de la faille de la vallée Roman. Le moment de la déformation et du métamorphisme régionaux se trouve restreint à environ 340-335 Ma par la datation 40Ar/39Ar de roche totale de l'ardoise dans les formations de Clam Harbour River et de Tracadie Road. La déformation et le métamorphisme régionaux pourraient avoir découlé de l'enfouissement de roches plus anciennes du bloc de Guysborough, qui chevauche le groupe de Horton dans le secteur de Lochaber-Mulgrave à partir du sud, par suite d'une transpression dans une inflexion de retenue le long du système de failles de Chedabucto-vallée Roman pendant la juxtaposition des terranes d'Avalon et de Megum

Radio Properties of Low Redshift Broad Line Active Galactic Nuclei

The question as to whether the distribution of radio-loudness in active galactic nuclei (AGN) is actually bimodal has been discussed extensively in the literature. Futhermore, there have been claims that radio-loudness depends on black hole mass and Eddington ratio. We investigate these claims using the low redshift broad line AGN sample of Greene & Ho (2007), which consists of 8434 objects at z < 0.35 from the Sloan Digital Sky Survey Fourth Data Release (SDSS DR4). We obtained radio fluxes from the Very Large Array Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey for the SDSS AGN. Out of the 8434 SDSS AGN, 821 have corresponding observed radio fluxes in the FIRST survey. We calculated the radio-loudness parameter (R) for all objects above the FIRST detection limit (1 mJy), and an upper limit to R for the undetected objects. Using these data, the question of radio bimodality is investigated for different subsets of the total sample. We find no clear demarcation between the radio-loud (RL, R > 10) and radio-quiet (RQ, R < 10) objects, but instead fill in a more radio-intermediate population in a continuous fashion for all subsamples. We find that 4.7% of the AGN in the flux-limited subsample are RL based on core radio emission alone. We calculate the radio-loud fraction (RLF) as both a function of black hole mass and Eddington ratio. The RLF decreases (from 13% to 2%) as Eddington ratio increases over 2.5 order of magnitude. The RLF is nearly constant (~5%) over 4 decades in black hole mass, except for an increase at masses greater than 10^8 solar masses. We find for the FIRST detected subsample that 367 of the RL AGN have black hole masses less than 10^8 solar masses, a large enough number to indicate that RL AGN are not a product of only the most massive black holes in the local universe.Comment: 28 pages, 14 figures, accepted to A

Boston University Medical Center: Perspectives on Health Policy

Report of a symposium held at the Boston University Medical Center

Determining jumping performance from a single body-worn accelerometer using machine learning

External peak power in the countermovement jump is frequently used to monitor athlete training. The gold standard method uses force platforms, but they are unsuitable for field-based testing. However, alternatives based on jump flight time or Newtonian methods applied to inertial sensor data have not been sufficiently accurate for athlete monitoring. Instead, we developed a machine learning model based on characteristic features (functional principal components) extracted from a single body-worn accelerometer. Data were collected from 69 male and female athletes at recreational, club or national levels, who performed 696 jumps in total. We considered vertical countermovement jumps (with and without arm swing),sensor anatomical locations, machine learning models and whether to use resultant or triaxial signals. Using a novel surrogate model optimisation procedure, we obtained the lowest errors with a support vector machine when using the resultant signal from a lower back sensor in jumps without arm swing. This model had a peak power RMSE of 2.3 W·kg-1 (5.1% of the mean), estimated using nested cross validation and supported by an independent holdout test (2.0 W·kg-1). This error is lower than in previous studies, although it is not yet sufficiently accurate for a field-based method. Our results demonstrate that functional data representations work well in machine learning by reducing model complexity in applications where signals are aligned in time. Our optimisation procedure also was shown to be robust can be used in wider applications with low-cost, noisy objective functions

Investor Perceptions of Board Performance: Evidence From Uncontested Director Elections

This paper provides evidence that uncontested director elections provide informative polls of investor perceptions regarding board performance. We find that higher (lower) vote approval is associated with lower (higher) stock price reactions to subsequent announcements of management turnovers. In addition, firms with low vote approval are more likely to experience CEO turnover, greater board turnover, lower CEO compensation, fewer and better-received acquisitions, and more and better-received divestitures in the future. These findings hold after controlling for other variables reflecting or determining investor perceptions, suggesting that elections not only inform as a summary statistic, but incrementally inform as well