Discovery of mHz X-ray Oscillations in a Transient Ultraluminous X-ray Source in M82

We report the discovery of X-ray quasi-periodic oscillations (QPOs) at frequencies of 3-4 mHz from a transient ultraluminous X-ray source (ULX) X42.3+59 in M82. The QPOs are strong and broad and appear with weak or absent red noise, and are detected only in Chandra observations when the source is brighter than 10^40 ergs/s. The QPO behavior is similar to the type A-I QPOs found in XTE J1550-564, which is a subclass of low frequency QPOs with properties in between type A and B. Therefore, we identify the QPOs in X42.3+59 as of type A or B, and rule out the possibility of type C. With this identification, the mass of the black hole in X42.3+59 can be inferred as in the range of 12,000-43,000 solar masses by scaling the QPO frequency to that of the type A/B QPOs in stellar mass black holes. Cool disk emission is detected in one Chandra observation, and the disk inner radius suggests a similar black hole mass range. Black holes of such a high mass are able to produce an energy output in a manner similar to X42.3+59 by accreting from the interstellar medium directly.Comment: 5 pages, 1 figure, accepted for publication in The Astrophysical Journal Letter

Documenting Pressures Used for Manual Diagnosis and Treatment of Cervical Spine Somatic Dysfunction

Background: Palpatory assessment of free or restricted motion patterns is part of the diagnosis of spinal somatic dysfunction (SD). Diagnostically, local soft tissues are compressed (pre-loaded) over the structure of interest followed by one or more test impulses to assess the quality of the “end-feel” motion in several planes. These barrier sensations are often described qualitatively but have not been objectively quantified. Noninvasive, tactile pressure sensors built into a digital palpation monitoring system (IsoTOUCH®; Neuromuscular Engineering; Nashville TN, USA) were used to document loading and impulse pressures for palpatory segmental diagnosis and to first engage and then quickly move through a restrictive SD barrier using an osteopathic manipulative treatment (OMT) technique

A Separable Model for Dynamic Networks

Models of dynamic networks --- networks that evolve over time --- have manifold applications. We develop a discrete-time generative model for social network evolution that inherits the richness and flexibility of the class of exponential-family random graph models. The model --- a Separable Temporal ERGM (STERGM) --- facilitates separable modeling of the tie duration distributions and the structural dynamics of tie formation. We develop likelihood-based inference for the model, and provide computational algorithms for maximum likelihood estimation. We illustrate the interpretability of the model in analyzing a longitudinal network of friendship ties within a school.Comment: 28 pages (including a 4-page appendix); a substantial rewrite, with many corrections, changes in terminology, and a different analysis for the exampl

Effect of Prior Anterior Superior Iliac Spine Compression Testing on Second Assessor Findings: Implications for Inter-Examiner Reliability Testing

BACKGROUND: Osteopathic physicians use palpation to diagnose sacroiliac joint somatic dysfunction (SD) -- including the Anterior Superior Iliac Spine (ASIS) Compression Test for dysfunctional side lateralization. (Literature suggests right-sided lateralization in 80% of asymptomatic individuals). Accurate, reliable tests are crucial however to diagnose SD and kappa (κ) analysis is a gold-standard to determine the degree of interexaminer reliability for tests. Few studies have examined the effect the palpatory examination has on subsequent diagnostic findings and therefore on κ-values

The Use of Objective Data to Improve Interexaminer Reliability

BACKGROUND: In Osteopathic Manipulative Medicine (OMM) and Manual/Musculoskeletal Medicine (MMM), palpatory diagnosis is performed on a regular basis to diagnose somatic dysfunction (SD). This examination requires careful and precise touch coupled with subjective interpretation by individual examiners who may have been trained to evaluate SD through different methods. Interexaminer reliability studies aim to minimize variance by providing quantifiable scientific data to evaluate specific test protocols which can then be taught to practitioners. In a previous PCOM study, two examiners independently diagnosed innominate bone dysfunction lateralized using the ASIS compression test on a large group of subjects. A pressure monitoring system (IsoTOUCH®, Chattanooga TN) has been used in various studies at the PCOM Human Performance & Biomechanics Laboratory (Kuchera, Jean et al 2006 & Kuchera, Vardy et al 2005) to quantify or standardize forces used in palpatory diagnosis or OMM/MMM treatment applications. This study gathered data during the tesing phase of a new and improved model of this system, using the protocol of the previous ASIS interexaminer reliability study. The data collected during standardization of the system was analyzed in the same manner as the previous study to compare the results of interexaminer reliability to results achieved using live data feed for baseline pressure synchronization between examiners

Comparing Inter-Examiner Reliability Levels when Diagnosing Male & Female Innominate Dysfunctions Using a Hemi-Pelvise Compression Lateralization Test and Pelvic Landmark Levels.

BACKGROUND: When diagnosing innominate somatic dysfunctions it may be relevant to recognize that structural, functional, and hormonal differences exist between male and female pelvises. The female pelvis is less massive, ilia are less sloped, and female hormones influence ligamentous tension. Despite these differences, few studies have analyzed gender effects on inter-examiner reliability when using palpatory diagnosis to diagnose innominate dysfunctions. In this study, we hypothesized that interexaminer reliability would be higher in male subjects than in female subjects due cyclic variability of hormonal influence of ligamentous tension in the female pelvis. The kappa (κ) statistic was selected to evaluate inter-examiner reliability as it is designed to eliminate agreement by chance. The agreement scale as proposed by Landis and Koch was used in the evaluation if the κ-value

Inter-Examiner Reliability of an Anterior Superior Iliac Spine Compression Test used to Lateralize Pelvic Somatic Dysfunction to the Right Side or Not

BACKGROUND: Osteopathic physicians use a number of palpatory structural examinations to diagnose pelvic somatic dysfunction (SD). They may elect to use the Anterior Superior Iliac Spine (ASIS) Compression Test to lateralize the dysfunctional side. Accurate, reliable tests are crucial to neuromusculoskeletal diagnosis and this study employs the kappa (κ) analysis protocol recommended for assessing interexaminer reliability of manual medicine tests (published by the Fédération Internationale de Médecine Manuelle [FIMM]). κ-values ≥0.40 (moderate agreement) are considered to be acceptable for use in the clinical setting

The long-term evolution of the accreting millisecond X-ray pulsar Swift J1756.9-2508

We present a timing analysis of the 2009 outburst of the accreting millisecond X-ray pulsar Swift J1756.9-2508, and a re-analysis of the 2007 outburst. The source shows a short recurrence time of only ~2 years between outbursts. Thanks to the approximately 2 year long baseline of data, we can constrain the magnetic field of the neutron star to be 0.4x10^8 G < B < 9x10^8 G, which is within the range of typical accreting millisecond pulsars. The 2009 timing analysis allows us to put constraints on the accretion torque: the spin frequency derivative within the outburst has an upper limit of $|\dot{\nu}| < 3x10^-13 Hz/s at the 95% confidence level. A study of pulse profiles and their evolution during the outburst is analyzed, suggesting a systematic change of shape that depends on the outburst phase.Comment: 7 pages, 4 figures, submitted to MNRA

On the nature of the "radio quiet" black hole binaries

The accretion/ejection coupling in accreting black hole binaries has been described by empirical relations between the X-ray/radio and X-ray/optical-infrared luminosities. These correlations were initially supposed to be universal. However, recently many sources have been found to produce jets that, given certain accretion-powered luminosities, are fainter than expected from the correlations. This shows that black holes with similar accretion flows can produce a broad range of outflows in power. Here we discuss whether typical parameters of the binary system, as well as the properties of the outburst, produce any effect on the energy output in the jet. We also define a jet-toy model in which the bulk Lorentz factor becomes larger than ~1 above ~0.1% of the Eddington luminosity. We finally compare the "radio quiet" black holes with the neutron stars.Comment: in the Proceedings of IAU Symposium 275, "Jets at all Scales", Buenos Aires, Argentina, 13-17 September 2010, eds. G.E. Romero, R.A. Sunyaev and T. Bellon

Orbital Period and Outburst Luminosity of Transient Low Mass X-ray Binaries

In this paper we investigate the relation between the maximal luminosity of X-ray outburst and the orbital period in transient low mass X-ray binaries (or soft X-ray transients) observed by the Rossi X-ray Timing Explorer (RXTE) in the past decade. We find that the maximal luminosity (3-200 keV) in Eddington unit generally increases with increasing orbital period, which does not show a luminosity saturation but in general agrees with theoretical prediction. The peak luminosities in ultra-compact binaries might be higher than those with orbital period of 2-4 h, but more data are needed to make the claim. We also find that there is no significant difference in the 3-200 keV outburst peak luminosity between neutron star systems and black hole systems with orbital periods above 4 h; however, there might be significant difference at smaller orbital period where only neutron star systems are observed and radiatively ineffcient accretion flow is expected to work at the low luminosities for black hole accreters.Comment: 28 pages, 5 figures, accepted by Ap