Nonlinear Dynamics of a Bose-Einstein Condensate in a Magnetic Waveguide

We have studied the internal and external dynamics of a Bose-Einstein condensate in an anharmonic magnetic waveguide. An oscillating condensate experiences a strong coupling between the center of mass motion and the internal collective modes. Due to the anharmonicity of the magnetic potential, not only the center of mass motion shows harmonic frequency generation, but also the internal dynamics exhibit nonlinear frequency mixing. We describe the data with a theoretical model to high accuracy. For strong excitations we test the experimental data for indications of a chaotic behavior.Comment: 4 pages, 4 figure

The Hard X-Ray View of Reflection, Absorption, and the Disk-Jet Connection in the Radio-Loud AGN 3C 33

We present results from Suzaku and Swift observations of the nearby radio galaxy 3C 33, and investigate the nature of absorption, reflection, and jet production in this source. We model the 0.5-100 keV nuclear continuum with a power law that is transmitted either through one or more layers of pc-scale neutral material, or through a modestly ionized pc-scale obscurer. The standard signatures of reflection from a neutral accretion disk are absent in 3C 33: there is no evidence of a relativistically blurred Fe K$\alpha$ emission line, and no Compton reflection hump above 10 keV. We find the upper limit to the neutral reflection fraction is R<0.41 for an e-folding energy of 1 GeV. We observe a narrow, neutral Fe K$\alpha$ line, which is likely to originate at least 2,000 R_s from the black hole. We show that the weakness of reflection features in 3C 33 is consistent with two interpretations: either the inner accretion flow is highly ionized, or the black-hole spin configuration is retrograde with respect to the accreting material.Comment: 12 pages, 11 figures, 4 tables. Accepted for publication in Ap

Towards More Practical Linear Programming-based Techniques for Algorithmic Mechanism Design

R. Lavy and C. Swamy (FOCS 2005, J. ACM 2011) introduced a general method for obtaining truthful-in-expectation mechanisms from linear programming based approximation algorithms. Due to the use of the Ellipsoid method, a direct implementation of the method is unlikely to be efficient in practice. We propose to use the much simpler and usually faster multiplicative weights update method instead. The simplification comes at the cost of slightly weaker approximation and truthfulness guarantees

The pharmacokinetics of nebulized nanocrystal budesonide suspension in healthy volunteers.

Nanocrystal budesonide (nanobudesonide) is a suspension for nebulization in patients with steroid-responsive pulmonary diseases such as asthma. The pharmacokinetics and safety of the product were compared to those of Pulmicort Respules. Sixteen healthy volunteers were administered nanobudesonide 0.5 and 1.0 mg, Pulmicort Respules 0.5 mg, and placebo in a four-way, randomized crossover design. All nebulized formulations were well tolerated, with no evidence of bronchospasm. Nebulization times were significantly shorter for nanobudesonide compared to Pulmicort Respules. Because of a low oral bioavailability, plasma concentration of budesonide is a good marker of lung-delivered dose. The pharmacokinetics of nanobudesonide 0.5 and 1.0 mg were approximately dose proportional with respect to Cmax, AUC(0-t), and AUC(0-infinity). Nanobudesonide 0.5 mg and Pulmicort Respules 0.5 mg exhibited similar AUCs, suggesting a similar extent of pulmonary absorption. A higher Cmax was noted with nanobudesonide 0.5 mg, and the tmax was significantly different, suggesting a more rapid rate of drug delivery of nanobudesonide 0.5 mg than Pulmicort Respules. In conclusion, nebulized nanobudesonide 0.5 mg was safe in healthy volunteers, with a similar extent of absorption as Pulmicort Respules

Experimental investigation of ultracold atom-molecule collisions

Ultracold collisions between Cs atoms and Cs2 dimers in the electronic ground state are observed in an optically trapped gas of atoms and molecules. The Cs2 molecules are formed in the triplet ground state by cw-photoassociation through the outer well of the 0g-(P3/2) excited electronic state. Inelastic atom-molecule collisions converting internal excitation into kinetic energy lead to a loss of Cs2 molecules from the dipole trap. Rate coefficients are determined for collisions involving Cs atoms in either the F=3 or F=4 hyperfine ground state and Cs2 molecules in either highly vibrationally excited states (v'=32-47) or in low vibrational states (v'=4-6) of the a ^3 Sigma_u^+ triplet ground state. The rate coefficients beta ~10^{-10} cm^3/s are found to be largely independent of the vibrational and rotational excitation indicating unitary limited cross sections.Comment: 4 pages, 3 figures, submitted for publicatio

Pharmacologic management of the opioid neonatal abstinence syndrome.

Opioid use in pregnant women has increased over the last decade. Following birth, infants with in utero exposure demonstrate signs and symptoms of withdrawal known as the neonatal abstinence syndrome (NAS). Infants express a spectrum of disease, with most requiring the administration of pharmacologic therapy to ensure proper growth and development. Treatment often involves prolonged hospitalization. There is a general lack of high-quality clinical trial data to guide optimal therapy, and significant heterogeneity in treatment approaches. Emerging trends in the treatment of infants with NAS include the use of sublingual buprenorphine, transition to outpatient therapy, and pharmacogenetic risk stratification

Thermal Instability and the Formation of Clumpy Gas Clouds

The radiative cooling of optically thin gaseous regions and the formation of a two-phase medium and of cold gas clouds with a clumpy substructure is investigated. In optically thin clouds, the growth rate of small isobaric density perturbations is independent of their length scale. However, the growth of a perturbation is limited by its transition from isobaric to isochoric cooling. The temperature at which this transition occurs decreases with the length scale of the perturbation. Consequently small scale perturbations have the potential to reach higher amplitudes than large scale perturbations. When the amplitude becomes nonlinear, advection overtakes the pressure gradient in promoting the compression resulting in an accelerated growth of the disturbance. The critical temperature for transition depends on the initial amplitude. The fluctuations which can first reach nonlinearity before their isobaric to isochoric transition will determine the characteristic size and mass of the cold dense clumps which would emerge from the cooling of an initially nearly homogeneous region of gas. Thermal conduction is in general very efficient in erasing isobaric, small-scale fluctuations, suppressing a cooling instability. A weak, tangled magnetic field can however reduce the conductive heat flux enough for low-amplitude fluctuations to grow isobarically and become non-linear if their length scales are of order 0.01 pc. Finally, we demonstrate how a 2-phase medium, with cold clumps being pressure confined in a diffuse hot residual background component, would be sustained if there is adequate heating to compensate the energy loss.Comment: 26 pages, Latex, 10 postscript figures, ApJ, in pres

Population Pharmacokinetic and Pharmacodynamic Analysis of Buprenorphine for the Treatment of Neonatal Abstinence Syndrome

Neonatal abstinence syndrome (NAS) is a condition affecting newborns exposed to an opioid in utero. Symptoms of NAS include excessive crying, poor feeding, and disordered autonomic control. Up to 2/3 of infants will require pharmacologic therapies to reach symptom control. Opioids including morphine and methadone are the current first-line treatments. Buprenorphine is being investigated as a treatment of NAS. The purpose of this analysis was to evaluate the pharmacokinetics (PK) and pharmacodynamics (PD) of BUP in infants with NAS. Poster presented at American Society for Clinical Pharmacology and Therapeutics (ASCPT) 2017 Annual Meeting, March 15-18, 2017 in Washington DC.https://jdc.jefferson.edu/petposters/1004/thumbnail.jp