Conversion of a gastric band into an intraperitoneal port in a patient with optimally debulked stage 3C serous ovarian carcinoma

Intraperitoneal (IP) chemotherapy in women with optimally debulked stage 3 ovarian cancer improves overall survival and progression-free survival, and its use has been encouraged in the adjuvant treatment of appropriately selected patients (Armstrong et al., 2006; Jaaback and Johnson, 2006). We describe a case in which a previously inserted adjustable gastric band was converted to an IP chemotherapy port during a laparotomy for advanced ovarian cancer

Can the Japan-Philippines Economic Partnership Agreement (JPEPA) Benefit Philippine Consumer Goods Exporters?

Why has the Philippines not been getting a larger slice of the Japanese market as compared with other ASEAN countries and with China? What factors prevent it from this? Can the talks on the Japan-Philippines Economic Partnership Agreement (JPEPA) help address these concerns? This Policy Notes dwells on these issues as it examines the opportunities and constraints for Philippine consumer goods exports in the Japanese market and in the areas where the JPEPA may help.small and medium enterprises, bilateral agreements, Japan-Philippines economic partnership, consumer goods exports

On the Formation of Runaway Stars BN and x in the Orion Nebula Cluster

We explore scenarios for the dynamical ejection of stars BN and x from source I in the Kleinmann-Low nebula of the Orion Nebula Cluster (ONC), which is important for being the closest region of massive star formation. This ejection would cause source I to become a close binary or a merger product of two stars. We thus consider binary-binary encounters as the mechanism to produce this event. By running a large suite of $N$-body simulations, we find that it is nearly impossible to match the observations when using the commonly adopted masses for the participants, especially a source I mass of $7\:{\rm{M}}_\odot$. The only way to recreate the event is if source I is more massive, i.e., $\sim20\:{\rm{M}}_\odot$. However, even in this case, the likelihood of reproducing the observed system is low. We discuss the implications of these results for understanding this important star-forming region.Comment: 7 pages, 4 figures, 1 table. Accepted by A&A Letter

When is Eaton's Markov chain irreducible?

Consider a parametric statistical model $P(\mathrm{d}x|\theta)$ and an improper prior distribution $\nu(\mathrm{d}\theta)$ that together yield a (proper) formal posterior distribution $Q(\mathrm{d}\theta|x)$. The prior is called strongly admissible if the generalized Bayes estimator of every bounded function of $\theta$ is admissible under squared error loss. Eaton [Ann. Statist. 20 (1992) 1147--1179] has shown that a sufficient condition for strong admissibility of $\nu$ is the local recurrence of the Markov chain whose transition function is $R(\theta,\mathrm{d}\eta)=\int Q(\mathrm{d}\eta|x)P(\mathrm {d}x|\theta)$. Applications of this result and its extensions are often greatly simplified when the Markov chain associated with $R$ is irreducible. However, establishing irreducibility can be difficult. In this paper, we provide a characterization of irreducibility for general state space Markov chains and use this characterization to develop an easily checked, necessary and sufficient condition for irreducibility of Eaton's Markov chain. All that is required to check this condition is a simple examination of $P$ and $\nu$. Application of the main result is illustrated using two examples.Comment: Published at http://dx.doi.org/10.3150/07-BEJ6191 in the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm

Atmospheric Circulation of Brown Dwarfs and Jupiter and Saturn-like Planets: Zonal Jets, Long-term Variability, and QBO-type Oscillations

Brown dwarfs and directly imaged giant planets exhibit significant evidence for active atmospheric circulation, which induces a large-scale patchiness in the cloud structure that evolves significantly over time, as evidenced by infrared light curves and Doppler maps. These observations raise critical questions about the fundamental nature of the circulation, its time variability, and the overall relationship to the circulation on Jupiter and Saturn. Jupiter and Saturn themselves exhibit numerous robust zonal (east-west) jet streams at the cloud level; moreover, both planets exhibit long-term stratospheric oscillations involving perturbations of zonal wind and temperature that propagate downward over time on timescales of ~4 years (Jupiter) and ~15 years (Saturn). These oscillations, dubbed the Quasi Quadrennial Oscillation (QQO) for Jupiter and the Semi-Annual Oscillation (SAO) on Saturn, are thought to be analogous to the Quasi-Biennial Oscillation (QBO) on Earth, which is driven by upward propagation of equatorial waves from the troposphere. To investigate these issues, we here present global, three-dimensional, high-resolution numerical simulations of the flow in the stratified atmosphere--overlying the convective interior--of brown dwarfs and Jupiter-like planets. The effect of interior convection is parameterized by inducing small-scale, randomly varying perturbations in the radiative-convective boundary at the base of the model. In the simulations, the convective perturbations generate atmospheric waves and turbulence that interact with the rotation to produce numerous zonal jets. Moreover, the equatorial stratosphere exhibits stacked eastward and westward jets that migrate downward over time, exactly as occurs in the terrestrial QBO, Jovian QQO, and Saturnian SAO. This is the first demonstration of a QBO-like phenomenon in 3D numerical simulations of a giant planet.Comment: 27 pages, 15 figures, in press at ApJ; this is the revised (accepted) version, which includes a major new section providing detailed analysis of the types of wave modes present in the model, and characterizing the wave-mean-flow interactions by which they generate the QBO-like oscillation

Effects of Geometric Phases in Josephson Junction Arrays

We show that the en route vortex velocity dependent part of the Magnus force in a Josephson junction array is effectively zero, and predict zero Hall effect in the classical limit. However, geometric phases due to the finite superfluid density at superconductor grains have a profound influence on the quantum dynamics of vortices. Subsequently we find rich and complex Hall behaviors analogous to the Thouless-Kohmoto-Nightingale-den Nijs effect in the quantum regime.Comment: Latex, 11 pages, appeared in Phys. Rev. Lett. v.77, 562 (1996) with minor change

A second-order class-D audio amplifier

Class-D audio amplifiers are particularly efficient, and this efficiency has led to their ubiquity in a wide range of modern electronic appliances. Their output takes the form of a high-frequency square wave whose duty cycle (ratio of on-time to off-time) is modulated at low frequency according to the audio signal. A mathematical model is developed here for a second-order class-D amplifier design (i.e., containing one second-order integrator) with negative feedback. We derive exact expressions for the dominant distortion terms, corresponding to a general audio input signal, and confirm these predictions with simulations. We also show how the observed phenomenon of “pulse skipping” arises from an instability of the analytical solution upon which the distortion calculations are based, and we provide predictions of the circumstances under which pulse skipping will take place, based on a stability analysis. These predictions are confirmed by simulations

Hunting for Runaways from the Orion Nebula Cluster

We use Gaia DR2 to hunt for runaway stars from the Orion Nebula Cluster (ONC). We search a region extending 45{\deg} around the ONC and out to 1 kpc to find sources that overlapped in angular position with the cluster in the last ~10 Myr. We find ~17,000 runaway/walkaway candidates satisfy this 2D traceback condition. Most of these are expected to be contaminants, e.g., caused by Galactic streaming motions of stars at different distances. We thus examine six further tests to help identify real runaways, namely: (1) possessing young stellar object (YSO) colors and magnitudes based on Gaia optical photometry; (2) having IR excess consistent with YSOs based on 2MASS and WISE photometry; (3) having a high degree of optical variability; (4) having closest approach distances well constrained to within the cluster half-mass radius; (5) having ejection directions that avoid the main Galactic streaming contamination zone; and (6) having a required radial velocity (RV) for 3D overlap of reasonable magnitude (or, for the 7% of candidates with measured RVs, satisfying 3D traceback). Thirteen sources, not previously noted as Orion members, pass all these tests, while another twelve are similarly promising, except they are in the main Galactic streaming contamination zone. Among these 25 ejection candidates, ten with measured RVs pass the most restrictive 3D traceback condition. We present full lists of runaway/walkaway candidates, estimate the high-velocity population ejected from the ONC and discuss its implications for cluster formation theories via comparison with numerical simulations.Comment: 22 pages, 10 figures, and 5 tables. Accepted for publication in Ap