Re-entrant pinning of Wigner molecules in a magnetic field due to a Coulomb impurity

Pinning of magnetic-field induced Wigner molecules (WMs) confined in parabolic two-dimensional quantum dots by a charged defect is studied by an exact diagonalization approach. We found a re-entrant pinning of the WMs as function of the magnetic field, a magnetic field induced re-orientation of the WMs and a qualitatively different pinning behaviour in the presence of a positive and negative Coulomb impurity

Power-law dependence of the angular momentum transition fields in few-electron quantum dots

We show that the critical magnetic fields at which a few-electron quantum dot undergoes transitions between successive values of its angular momentum (M), for large M values follow a very simple power-law dependence on the effective inter-electron interaction strength. We obtain this power law analytically from a quasi-classical treatment and demonstrate its nearly-universal validity by comparison with the results of exact diagonalization.Comment: Uses RevTeX4, 6 figures included in the tex

Accuracy of the Hartree-Fock method for Wigner molecules at high magnetic fields

Few-electron systems confined in two-dimensional parabolic quantum dots at high magnetic fields are studied by the Hartree-Fock (HF) and exact diagonalization methods. A generalized multicenter Gaussian basis is proposed in the HF method. A comparison of the HF and exact results allows us to discuss the relevance of the symmetry of the charge density distribution for the accuracy of the HF method. It is shown that the energy estimates obtained with the broken-symmetry HF wave functions become exact in the infinite magnetic-field limit. In this limit the charge density of the broken-symmetry solution can be identified with the classical charge distribution.Comment: to appear in EPJ

Correlation between electrons and vortices in quantum dots

Exact many-body wave functions for quantum dots containing up to four interacting electrons are computed and we investigated the distribution of the wave function nodes, also called vortices. For this purpose, we evaluate the reduced wave function by fixing the positions of all but one electron and determine the locations of its zeros. We find that the zeros are strongly correlated with respect to each other and with respect to the position of the electrons and formulate rules describing their distribution. No multiple zeros are found, i.e. vortices with vorticity larger than one. Our exact calculations are compared to results extracted from the recently proposed rotating electron molecule (REM) wave functions

Deploying elastic routing capability in an SDN/NFV-enabled environment

SDN and NFV are two paradigms that introduce unseen flexibility in telecom networks. Where previously telecom services were provided by dedicated hardware and associated (vendor-specific) protocols, SDN enables to control telecom networks through specialized software running on controllers. NFV enables highly optimized packet-processing network functions to run on generic/multi-purpose hardware such as x86 servers. Although the possibilities of SDN and NFV are well-known, concrete control and orchestration architectures are still under design and few prototype validations are available. In this demo we demonstrate the dynamic up-and downscaling of an elastic router supporting NFV-based network management, for example needed in a VPN service. The framework which enables this elasticity is the UNIFY ESCAPE environment, which is a PoC following an ETSI NFV MANO-conform architecture. This demo is one of the first to demonstrate a fully closed control loop for scaling NFs in an SDN/NFV control and orchestration architecture

Embedded Software V&V using Virtual Platforms for Powertrain applications

International audienceCurrent development trends for automotive products are driven by time to market reduction, cost optimization, and quality improvement. Dual to these business constraints are demands for innovation and safety conformance which impose increasing complexity on embedded systems. To address these challenges impacting software and hardware to improve system dependability, new methodology and tools need to be set-up. The use of representative virtual platforms combining speed and accuracy allows earlier software development, improved system testing, and fault injection analysis, with a high potential for reuse of system IPs (including both hardware and software). In this paper, we will present investigation on new methods and associated results using a simplified virtual platform to test a powertrain application

Multi-domain service orchestration over networks and clouds: a unified approach

End-to-end service delivery often includes transparently inserted Network Functions (NFs) in the path. Flexible service chaining will require dynamic instantiation of both NFs and traffic forwarding overlays. Virtualization techniques in compute and networking, like cloud and Software Defined Networking (SDN), promise such flexibility for service providers. However, patching together existing cloud and network control mechanisms necessarily puts one over the above, e.g., OpenDaylight under an OpenStack controller. We designed and implemented a joint cloud and network resource virtualization and programming API. In this demonstration, we show that our abstraction is capable for flexible service chaining control over any technology domain

Thermoelectric Processes and Materials

Contains reports on four research projects.U. S. Navy (Office of Naval Research) under Contract Nonr-1841(51

Recurrent solitary fibrous tumor of lumbar spine with vertebral body involvement: imaging features and differential diagnosis with report of a case

AbstractSolitary fibrous tumors (SFTs) of the spine are exceedingly rare tumors of mesenchymal origin. Most spinal SFTs arise from the thoracic spine, followed by cervical spine, and last lumbar spine with only 6 cases reported in literature. SFTs represent a wide range of neoplasms, ranging from benign to malignant. These tumors can develop a late recurrence, even after a decade or more of initial presentation, requiring long-term follow-up. We present a case of recurrent SFT of the lumbar spine with vertebral body involvement, presenting more than a decade after initial resection. It was initially misdiagnosed as a paraganglioma. To the best of our knowledge, there have been only 3 previous cases reporting SFT with vertebral body involvement

Ryanodine receptors are targeted by anti-apoptotic Bcl-X-L involving its BH4 domain and Lys87 from its BH3 domain

Anti-apoptotic B-cell lymphoma 2 (Bcl-2) family members target several intracellular Ca2+-transport systems. Bcl-2, via its N-terminal Bcl-2 homology (BH) 4 domain, inhibits both inositol 1,4,5-trisphosphate receptors (IP(3)Rs) and ryanodine receptors (RyRs), while Bcl-X-L, likely independently of its BH4 domain, sensitizes IP3Rs. It remains elusive whether Bcl-XL can also target and modulate RyRs. Here, Bcl-X-L co-immunoprecipitated with RyR3 expressed in HEK293 cells. Mammalian protein-protein interaction trap (MAPPIT) and surface plasmon resonance (SPR) showed that Bcl-XL bound to the central domain of RyR3 via its BH4 domain, although to a lesser extent compared to the BH4 domain of Bcl-2. Consistent with the ability of the BH4 domain of Bcl-X-L to bind to RyRs, loading the BH4-Bcl-X-L peptide into RyR3-overexpressing HEK293 cells or in rat hippocampal neurons suppressed RyR-mediated Ca2+ release. In silico superposition of the 3D-structures of Bcl-2 and Bcl-XL indicated that Lys87 of the BH3 domain of Bcl-XL could be important for interacting with RyRs. In contrast to Bcl-X-L, the Bcl-X-L(K87D) mutant displayed lower binding affinity for RyR3 and a reduced inhibition of RyR-mediated Ca2+ release. These data suggest that Bcl-X-L binds to RyR channels via its BH4 domain, but also its BH3 domain, more specific Lys87, contributes to the interaction