107 research outputs found
Global Operator Calculus on Spin Groups
Acknowledgements The work of P. Cerejeiras, M. Ferreira, and U. Kähler was supported by Portuguese
funds through CIDMA-Center for Research and Development in Mathematics and Applications, and FCT–
“Fundação para a Ciência e a Tecnologia”, within project UIDB/04106/2020 and UIDP/04106/2020. The
present paper was supported by the project “Global operator calculi on compact and non-compact Lie
groups”, Ações Integradas Luso-Alemãs – Acção No. A-42/16.
Funding Open access funding provided by FCT|FCCN (b-on).n this paper, we use the representation theory of the group Spin(m) to develop aspects of the global symbolic calculus of pseudo-differential operators on Spin(3) and Spin(4) in the sense of Ruzhansky–Turunen–Wirth. A detailed study of Spin(3) and Spin(4)-representations is made including recurrence relations and natural differential operators acting on matrix coefficients. We establish the calculus of left-invariant differential operators and of difference operators on the group Spin(4) and apply this to give criteria for the subellipticity and the global hypoellipticity of pseudo-differential operators in terms of their matrix-valued full symbols. Several examples of first and second order globally hypoelliptic differential operators are given, including some that are locally neither invertible nor hypoelliptic. The paper presents a particular case study for higher dimensional spin groups.info:eu-repo/semantics/publishedVersio
Therapie-induzierte Hyperinsulinämie: Wie kann man die unkontrollierte Insulindosiserhöhung vermeiden?
An interpolation problem arising in a coupling of the finite element method with holomorphic basis functions
The purpose of this paper is to prove an interpolation theorem which arises in a method of coupling of a finite
element and an analytical solution for boundary value problems with singularities
A wavelet based numerical method for nonlinear partial differential equations
The purpose of this paper is to present a wavelet–Galerkin scheme for solving
nonlinear elliptic partial differential equations. We select as trial spaces a nested
sequence of spaces from an appropriate biorthogonal multiscale analysis. This gives
rise to a nonlinear discretized system. To overcome the problems of nonlinearity, we
apply the machinery of interpolating wavelets to obtain knot oriented quadrature
rules. Finally, Newton’s method is applied to approximate the solution in the given
ansatz space. The results of some numerical experiments with different biorthogonal
systems, confirming the applicability of our scheme, are presented.Instituto de Cooperação Científica e Tecnológica Internacional - Acções Integradas Luso-Alemãs (DAAD/ICCTI) - Projecto DAAD/ICCTI nº 01141
Analysis of BRAF and NRAS Mutation Status in Advanced Melanoma Patients Treated with Anti-CTLA-4 Antibodies: Association with Overall Survival?
Ipilimumab and tremelimumab are human monoclonal antibodies (Abs) against cytotoxic T-lymphocyte antigen-4 (CTLA-4). Ipilimumab was the first agent to show a statistically significant benefit in overall survival in advanced melanoma patients. Currently, there is no proven association between the BRAFV600 mutation and the disease control rate in response to ipilimumab. This analysis was carried out to assess if BRAFV600 and NRAS mutation status affects the clinical outcome of anti-CTLA-4-treated melanoma patients. This is a retrospective multi-center analysis of 101 patients, with confirmed BRAF and NRAS mutation status, treated with anti-CTLA-4 antibodies from December 2006 until August 2012. The median overall survival, defined from the treatment start date with the anti-CTLA-4. Abs-treatment to death or till last follow up, of BRAFV600 or NRAS mutant patients (n = 62) was 10.12 months (95% CI 6.78-13.2) compared to 8.26 months (95% CI 6.02-19.9) in BRAFV600/NRASwt subpopulation (n = 39) (p = 0.67). The median OS of NRAS mutated patients (n = 24) was 12.1 months and although was prolonged compared to the median OS of BRAF mutated patients (n = 38, mOS = 8.03 months) or BRAFV600/NRASwt patients (n = 39, mOS = 8.26 months) the difference didn't reach statistical significance (p = 0.56). 69 patients were able to complete 4 cycles of anti-CTLA-4 treatment. Of the 24 patients treated with selected BRAF- or MEK-inhibitors, 16 patients received anti-CTLA 4 Abs following either a BRAF or MEK inhibitor with only 8 of them being able to finish 4 cycles of treatment. Based on our results, there is no difference in the median OS in patients treated with anti-CTLA-4 Abs implying that the BRAF/NRAS mutation status alone is not sufficient to predict the outcome of patients treated with anti-CTLA-4 Abs
Differential influence of vemurafenib and dabrafenib on patients' lymphocytes despite similar clinical efficacy in melanoma
In this study, we demonstrate that vemurafenib but not dabrafenib reduces peripheral lymphocyte counts in melanoma patients while both agents show similar clinical efficacy. Within the lymphocyte compartment, vemurafenib selectively decreases circulating CD4+ T cells and changes their phenotype and function. This indicates that selective BRAFi need to be assessed individually for immunomodulatory effects, especially, when planning combinations with immunotherapie
A convenient coordinatization of Siegel-Jacobi domains
We determine the homogeneous K\"ahler diffeomorphism which expresses the
K\"ahler two-form on the Siegel-Jacobi ball \mc{D}^J_n=\C^n\times \mc{D}_n as
the sum of the K\"ahler two-form on \C^n and the one on the Siegel ball
\mc{D}_n. The classical motion and quantum evolution on \mc{D}^J_n
determined by a hermitian linear Hamiltonian in the generators of the Jacobi
group G^J_n=H_n\rtimes\text{Sp}(n,\R)_{\C} are described by a matrix Riccati
equation on \mc{D}_n and a linear first order differential equation in
z\in\C^n, with coefficients depending also on W\in\mc{D}_n. denotes
the -dimensional Heisenberg group. The system of linear differential
equations attached to the matrix Riccati equation is a linear Hamiltonian
system on \mc{D}_n. When the transform is
applied, the first order differential equation in the variable
\eta=(\un-W\bar{W})^{-1}(z+W\bar{z})\in\C^n becomes decoupled from the motion
on the Siegel ball. Similar considerations are presented for the Siegel-Jacobi
upper half plane \mc{X}^J_n=\C^n\times\mc{X}_n, where \mc{X}_n denotes the
Siegel upper half plane.Comment: 32 pages, corrected typos, Latex, amsart, AMS font
Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR
Substantial experimental and theoretical efforts worldwide are devoted to
explore the phase diagram of strongly interacting matter. At LHC and top RHIC
energies, QCD matter is studied at very high temperatures and nearly vanishing
net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was
created at experiments at RHIC and LHC. The transition from the QGP back to the
hadron gas is found to be a smooth cross over. For larger net-baryon densities
and lower temperatures, it is expected that the QCD phase diagram exhibits a
rich structure, such as a first-order phase transition between hadronic and
partonic matter which terminates in a critical point, or exotic phases like
quarkyonic matter. The discovery of these landmarks would be a breakthrough in
our understanding of the strong interaction and is therefore in the focus of
various high-energy heavy-ion research programs. The Compressed Baryonic Matter
(CBM) experiment at FAIR will play a unique role in the exploration of the QCD
phase diagram in the region of high net-baryon densities, because it is
designed to run at unprecedented interaction rates. High-rate operation is the
key prerequisite for high-precision measurements of multi-differential
observables and of rare diagnostic probes which are sensitive to the dense
phase of the nuclear fireball. The goal of the CBM experiment at SIS100
(sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD
matter: the phase structure at large baryon-chemical potentials (mu_B > 500
MeV), effects of chiral symmetry, and the equation-of-state at high density as
it is expected to occur in the core of neutron stars. In this article, we
review the motivation for and the physics programme of CBM, including
activities before the start of data taking in 2022, in the context of the
worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal
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