714 research outputs found
Hong-Ou-Mandel-like two-droplet correlations
We present a numerical study of two-droplet pair correlations for in-phase
droplets walking on a vibrating bath. Two such walkers are launched towards a
common origin. As they approach, their carrier waves may overlap and the
droplets have a non-zero probability of forming a two-droplet bound state. The
likelihood of such pairing is quantified by measuring the probability of
finding the droplets in a bound state at late times. Three generic types of
two-droplet correlations are observed: promenading, orbiting and chasing pair
of walkers. For certain parameters, the droplets may become correlated for
certain initial path differences and remain uncorrelated for others, while in
other cases the droplets may never produce droplet pairs. These observations
pave the way for further studies of strongly correlated many-droplet behaviors
in the hydrodynamical quantum analogs of bouncing and walking droplets.Comment: 8 pages, 5 figure
Pilot-wave dynamics of two identical, in-phase bouncing droplet
A droplet bouncing on the surface of a vibrating liquid bath can move
horizontally guided by the wave it produces on impacting the bath. The wave
itself is modified by the environment, and thus the interactions of the moving
droplet with the surroundings are mediated through the wave. This forms an
example of a pilot-wave system. Taking the Oza Rosales Bush description for
walking droplets as a theoretical pilot-wave model, we investigate the dynamics
of two interacting identical, in-phase bouncing droplets theoretically and
numerically. A remarkably rich range of behaviors is encountered as a function
of the two system parameters, the ratio of inertia to drag, \k{appa}, and the
ratio of wave forcing to drag, \b{eta}. The droplets typically travel together
in a tightly bound pair, although they unbind when the wave forcing is large
and inertia is small or inertia is moderately large and wave forcing is
moderately small. Bound pairs can exhibit a range of trajectories depending on
parameter values, including straight lines, sub-diffusive random walks, and
closed loops. The droplets themselves may maintain their relative positions,
oscillate towards and away from one another, or interchange positions regularly
or chaotically as they travel. We explore these regimes and others and the
bifurcations between them through analytic and numerical linear stability
analyses and through fully nonlinear numerical simulation.Comment: 17 pages, 17 figure
Rosiglitazone and Fenofibrate Additive Effects on Lipids
Background. To evaluate the effect of rosiglitazone, fenofibrate, or their combined use on plasma lipids in normoglycemic healthy adults. Methods and Results. Subjects were randomized in a double-blind fashion to rosiglitazone + placebo, fenofibrate + placebo, rosiglitazone + fenofibrate, or matching double placebo. The between-group difference in the change in fasting TG, high-density lipoprotein cholesterol (HDL-C), LDL-C, and plasma apolipoproteins A-I, A-II, and C-III level were compared after 12 weeks of treatment. A total of 548 subjects were screened and 41 met the inclusion criteria. After 12 weeks of therapy, the median change in the triglyceride levels showed a significant reduction ranging from 47 to 55 mg per deciliter in the fenofibrate only and rosiglitazone/fenofibrate groups compared with placebo (P = 0.0496). However, the rosiglitazone only group did not show significant change in triglyceride level. The change in the Apo AII showed increase in all the treatment groups compared with placebo (P = 0.009). There was also significant change in the Apo CIII that showed reduction of its level in the fenofibrate only and rosiglitazone/fenofibrate groups (P = 0.0003). Conclusion. Rosiglitazone does not appear to modulate hypertriglyceridemia in patients with elevated triglycerides independent of glucose metabolism
A Rare Case of Effusive Constrictive Cholesterol Pericarditis: A Case Report and Review
Effusive constrictive cholesterol pericarditis is exceedingly rare. Most cases have an unclear etiology but can be associated with rheumatoid arthritis, tuberculosis infection, and hypothyroidism. The hallmark of the effusion is the distinctively high levels of cholesterol. We present the case of a 68-year-old male with prolonged symptoms of dyspnea with associated moderate pericardial effusion that were later determined to be constrictive effusive etiology, and the patient was referred for stripping with pathologic cholesterol crystal formation on pathology review
A Case of Congenitally Corrected Transposition of the Great Arteries Discovered on Coronary Computed Tomography
Congenitally corrected transposition of the great arteries is a rare condition accounting for less than 1% of all congenital cardiac diseases. The fundamental nature of this condition involves a blend of atrioventricular as well as ventriculoarterial discordance. Congenitally corrected transposition of the great arteries is classically associated with three additional abnormalities, including ventricular septal defect, right ventricular outflow tract obstruction, and tricuspid valve abnormalities. Patients with this anomaly have been shown to exhibit reduced exercise tolerance as well as reduced health-related quality of life when compared to patients with normal cardiovascular anatomy. We present the case of a 33-year-old active duty lieutenant in the United States Air Force referred to the cardiology clinic for evaluation of valvular heart disease with subsequent discovery of congenitally corrected transposition of the great arteries on cardiac gated computed tomography
CT and MR imaging of retroperitoneal schwannoma
AbstractThe purpose of this presentation is to allow the radiologist to discuss the diagnosis of retroperitoneal schwannoma, involving mostly a fortuitous discovery and a misleading clinical presentation. We present 4 cases of retroperitoneal schwannoma, two having benefited from a surgery and two others of a therapeutic abstention. The retropritoneal localization and the imaging are good indicator elements of this pathology. The constant improvement of the CT and MR imaging allows a better approach of this entity also by specifying its localization and its anatomical relationships to guide the therapeutic attitude which must be remain mutidisciplinary
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