40 research outputs found
Hydrodynamic Limit for an Hamiltonian System with Boundary Conditions and Conservative Noise
We study the hyperbolic scaling limit for a chain of N coupled anharmonic
oscillators. The chain is attached to a point on the left and there is a force
(tension) acting on the right. In order to provide good ergodic
properties to the system, we perturb the Hamiltonian dynamics with random local
exchanges of velocities between the particles, so that momentum and energy are
locally conserved. We prove that in the macroscopic limit the distributions of
the elongation, momentum and energy, converge to the solution of the Euler
system of equations, in the smooth regime.Comment: New deeply revised version. 1 figure adde
The Ground State Energy of Dilute Bose Gas in Potentials with Positive Scattering Length
The leading term of the ground state energy/particle of a dilute gas of
bosons with mass in the thermodynamic limit is when
the density of the gas is , the interaction potential is non-negative and
the scattering length is positive. In this paper, we generalize the upper
bound part of this result to any interaction potential with positive scattering
length, i.e, and the lower bound part to some interaction potentials with
shallow and/or narrow negative parts.Comment: Latex 28 page
Hydrodynamic limit for the velocity flip model
We study the diffusive scaling limit for a chain of coupled oscillators.
In order to provide the system with good ergodic properties, we perturb the
Hamiltonian dynamics with random flips of velocities, so that the energy is
locally conserved. We derive the hydrodynamic equations by estimating the
relative entropy with respect to the local equilibrium state modified by a
correction term
Superdiffusion of energy in Hamiltonian systems perturbed by a conservative noise
We review some recent results on the anomalous diffusion of energy in systems
of 1D coupled oscillators and we revisit the role of momentum conservation.Comment: Proceedings of the conference PSPDE 2012
https://sites.google.com/site/meetingpspde
Bosonization, vicinal surfaces, and hydrodynamic fluctuation theory
Through a Euclidean path integral we establish that the density fluctuations
of a Fermi fluid in one dimension are related to vicinal surfaces and to the
stochastic dynamics of particles interacting through long range forces with
inverse distance decay. In the surface picture one easily obtains the Haldane
relation and identifies the scaling exponents governing the low energy,
Luttinger liquid behavior. For the stochastic particle model we develop a
hydrodynamic fluctuation theory, through which in some cases the large distance
Gaussian fluctuations are proved nonperturbatively
Free Energies of Dilute Bose gases: upper bound
We derive a upper bound on the free energy of a Bose gas system at density
and temperature . In combination with the lower bound derived
previously by Seiringer \cite{RS1}, our result proves that in the low density
limit, i.e., when , where denotes the scattering length of
the pair-interaction potential, the leading term of the free energy
difference per volume between interacting and ideal Bose gases is equal to
4\pi a (2\rho^2-[\rho-\rhoc]^2_+). Here, \rhoc(T) denotes the critical
density for Bose-Einstein condensation (for the ideal gas), and
denotes the positive part.Comment: 56 pages, no figure
Association of inflammatory biomarkers with clinical outcomes in nivolumab-treated patients with advanced hepatocellular carcinoma
Background & Aims: Nivolumab, a programmed death (PD)-1 (PD-1) inhibitor, led to durable responses, manageable safety, and increased survival in patients with advanced hepatocellular carcinoma (HCC). In our retrospective analysis, we studied the immunobiology and potential associations between biomarkers and outcomes with nivolumab in HCC. Methods: Fresh and archival tumour samples from dose-escalation and dose-expansion phases of the CheckMate 040 trial were analysed by immunohistochemistry and RNA sequencing to assess several inflammatory gene expression signatures, including CD274 (PD-ligand 1 [PD-L1]), CD8A, LAG3, and STAT1. Biomarkers were assessed for association with clinical outcomes (best overall response by blinded independent central review per RECIST v1.1 and overall survival [OS]). Results: Complete or partial tumour responses were observed in PD-L1-positive and PD-L1-negative patients treated with nivolumab monotherapy. Median OS was 28.1 (95% CI 18.2-n.a.) vs. 16.6 months (95% CI 14.2-20.2) for patients with tumour PD-L1 >= 1% vs. <1% (p = 0.03). Increased CD3 and CD8 showed a non-significant trend towards improved OS (both p = 0.08), and macrophage markers were not associated with OS. Tumour PD-1 and PD-L1 expression were associated with improved OS (p = 0.05 and p = 0.03, respectively). An inflammatory gene signature consisting of 4 genes was associated with improved objective response rate (p = 0.05) and OS (p = 0.01). Conclusions: PD-1 and PD-L1 expression, biomarkers of inflammation, and inflammatory gene signatures trended with improved survival and response. While further confirmation within a larger phase III trial is needed to evaluate predictive value of these biomarkers, these exploratory analyses suggest that anti-tumour immune response may play a role in the treatment benefit of nivolumab in HCC. Lay summary: Certain tests may be used to provide a picture of how a tumour is escaping the immune system, allowing it to continue to grow and create more tumours. Therapies such as nivolumab are designed to help the immune system fight the tumour. These tests may be used to determine how effective such therapies will be in the treatment of advanced liver cancer. (C) 2020 European Association for the Study of the Liver. Published by Elsevier B.V