Many-body effects in Landau levels: Non-commutative geometry and squeezed correlated states

We discuss symmetry-driven squeezing and coherent states of few-particle systems in magnetic fields. An operator approach using canonical transformations and the SU(1,1) algebras is developed for considering Coulomb correlations in the lowest Landau levels.Comment: 3 pages, 2 figures; to be reported at 17th Int. Conf. on High Magnetic Fields in Semiconductor Physics, Wuerzburg, Germany, July 30 - Aug 4, 200

Theory of non-equilibrium electronic Mach-Zehnder interferometer

We develop a theoretical description of interaction-induced phenomena in an electronic Mach-Zehnder interferometer formed by integer quantum Hall edge states (with \nu =1 and 2 channels) out of equilibrium. Using the non-equilibrium functional bosonization framework, we derive an effective action which contains all the physics of the problem. We apply the theory to the model of a short-range interaction and to a more realistic case of long-range Coulomb interaction. The theory takes into account interaction-induced effects of dispersion of plasmons, charging, and decoherence. In the case of long-range interaction we find a good agreement between our theoretical results for the visibility of Aharonov-Bohm oscillations and experimental data.Comment: 19 pages, 10 figure

Treatment of Bifocal Periprosthetic Fractures above and below a Knee after Tumor using Spanning Ilizarov Device : A Case Report

Copyright: © Indian Orthopaedic Research Group.INTRODUCTION: Multiple treatment options and internal and external devices have been recommended for periprosthetic fractures management around total knee arthroplasty. CASE REPORT: We present the case of the high-energy bifocal periprosthetic fractures of the femur and the tibia after total knee prosthesis following excision of a tumor. One of the fractures was an open tibial fracture Gustilo Type IIIB and the other - comminuted subtrochanteric fracture of the femur with extrusion of periprosthetic cement pieces out from the bone defect. The Ilizarov circular external fixator was used for the skeletal stabilization and early functional treatment in this compound case. CONCLUSION: The use of Ilizarov external fixator for patients with complex periprosthetic fractures, who present severe technical difficulties in bone stabilization, especially by concomitant severe soft-tissue damage after high-energy injuries, is a good surgical alternative.Peer reviewe

Temporary bridging trans-hip external fixation in damage control orthopaedics treatment after severe combat trauma : A clinical case series

Funding Information: We express our appreciation to Dr. Elina Jumtina for her help in preparing this manuscript. Publisher Copyright: © 2023 Elsevier LtdThe role of external fixation in Damage Control Orthopaedics has been well described. Temporary external fixation has been recommended to provide relative bone stability while the soft tissue heals, prior to formal open reduction and internal fixation. Temporary bridging external fixation, that spans the joint, is recommended as primary skeletal stabilization in complex intra-articular and peri-articular fractures, in extensive peri-articular soft-tissue damage around the knee, ankle, elbow and wrist joints. Works devoted to temporary trans-hip external fixation in treatment of complex high-energy injuries are relatively rare. The purpose of this article is to present our experience in using temporary hip spanning external fixation during primary treatment of six patients suffered from complex open intra-articular and peri-articular fractures of the proximal femoral bone with extensive soft tissue damage due to war blast or high-velocity gunshot trauma. Primary management was based on the concept of Advanced Trauma Life Support and Damage Control Orthopaedics. Conversion to definitive bone reconstruction was performed on the next stage of the treatment after general and local stabilization.publishersversionPeer reviewe

Loss Fluctuations and Temporal Correlations in Network Queues

We consider data losses in a single node of a packet-switched Internet-like network. We employ two distinct models, one with discrete and the other with continuous one-dimensional random walks, representing the state of a queue in a router. Both models {have} a built-in critical behavior with {a sharp} transition from exponentially small to finite losses. It turns out that the finite capacity of a buffer and the packet-dropping procedure give rise to specific boundary conditions which lead to strong loss rate fluctuations at the critical point even in the absence of such fluctuations in the data arrival process.Comment: 6 pages, 2 figures; an invited talk at the 1st Workshop on Physics-Inspired Paradigms in Wireless Communications and Networks, April 4th, 2008, Berlin, German

Phonon gap and localization lengths in floppy materials

Gels of semi-flexible polymers, network glasses made of low valence elements, softly compressed ellipses and dense suspensions under flow are examples of floppy materials. These systems present collective motions with almost no restoring force. We study theoretically and numerically the frequency-dependence of the response of these materials, and the length scales that characterize their elasticity. We show that isotropic floppy elastic networks present a phonon gap for frequencies smaller than a frequency $\omega^*$ governed by coordination, and that the elastic response is localized on a length scale $l_c\sim 1/\sqrt{\omega^*}$ that diverges as the phonon gap vanishes (with a logarithmic correction in the two dimensional case). $l_c$ also characterizes velocity correlations under shear, whereas another length scale $l^*\sim 1/\omega^*$ characterizes the effect of pinning boundaries on elasticity. We discuss the implications of our findings for suspensions flows, and the correspondence between floppy materials and amorphous solids near unjamming, where $l_c$ and $l^*$ have also been identified but where their roles are not fully understood

Loss of AND-34/BCAR3 Expression in Mice Results in Rupture of the Adult Lens

PURPOSE. AND-34/BCAR3 (Breast Cancer Anti-Estrogen Resistance 3) associates with the focal adhesion adaptor protein, p130CAS/BCAR1. Expression of AND-34 regulates epithelial cell growth pattern, motility, and growth factor dependence. We sought to establish the effects of the loss of AND-34 expression in a mammalian organism. METHODS. AND-34−/− mice were generated by homologous recombination. Histopathology, in situ hybridization, and western blotting were performed on murine tissues. RESULTS. Western analyses confirmed total loss of expression in AND-34−/− splenic lymphocytes. Mice lacking AND-34 are fertile and have normal longevity. While AND-34 is widely expressed in wild type mice, histologic analysis of multiple organs in AND-34−/− mice is unremarkable and analyses of lymphocyte development show no overt changes. A small percentage of AND-34−/− mice show distinctive small white eye lesions resulting from the migration of ruptured cortical lens tissue into the anterior chamber. Following initial vacuolization and liquefaction of the lens cortex first observed at postnatal day three, posterior lens rupture occurs in all AND-34−/− mice, beginning as early as three weeks and seen in all mice at three months. Western blot analysis and in situ hybridization confirmed the presence of AND-34 RNA and protein in lens epithelial cells, particularly at the lens equator. Prior data link AND-34 expression to the activation of Akt signaling. While Akt Ser 473 phosphorylation was readily detectable in AND-34+/+ lens epithelial cells, it was markedly reduced in the AND-34−/− lens epithelium. Basal levels of p130Cas phosphorylation were higher in AND-34+/+ than in AND-34−/− lens epithelium. CONCLUSIONS. These results demonstrate the loss of AND-34 dysregulates focal adhesion complex signaling in lens epithelial cells and suggest that AND-34-mediated signaling is required for maintenance of the structural integrity of the adult ocular lens.National Institutes of Health (RO1 CA114094); Logica Foundatio

Phase state of matter during metal and binary alloy conductor dispersion by a pulse of current

The paper covers the evolution of the liquid phase formed under heating metal conductors by a pulse of current with the density of [j=~106-:106] A/cm{2}. Following the theoretical assessment and experimental data, it was shown that the two-phase state (condensed phase - gas) during the early expansion of products of electric explosion of wires can be caused by the development of density fluctuations in the liquid phase of the metal. The density fluctuation formation is caused by the destruction of liquid phase clusters of short-range order. The study demonstrated the absence of the complete transition of the semiconductor matter into gas after the injection of energy exceeding the energy of sublimation E s

The diffusion of disruptive technologies

We identify novel technologies using textual analysis of patents, job postings, and earnings calls. Our approach enables us to identify and document the diffusion of 29 disruptive technologies across firms and labor markets in the U.S. Five stylized facts emerge from our data. First, the locations where technologies are developed that later disrupt businesses are geographically highly concentrated, even more so than overall patenting. Second, as the technologies mature and the number of new jobs related to them grows, they gradually spread across space. While initial hiring is concentrated in high-skilled jobs, over time the mean skill level in new positions associated with the technologies declines, broadening the types of jobs that adopt a given technology. At the same time, the geographic diffusion of low-skilled positions is significantly faster than higher-skilled ones, so that the locations where initial discoveries were made retain their leading positions among high-paying positions for decades. Finally, these technology hubs are more likely to arise in areas with universities and high skilled labor pools

Do Equity Financing Cycles Matter? Evidence from Biotechnology Alliances

While the variability of public equity financing has been long recognized, its impact on firms has attracted little empirical scrutiny. This paper examines one setting where theory suggests that variations in financing conditions should matter, alliances between small R&D firms and major corporations: Aghion and Tirole [1994] suggest that when financial markets are weak, assigning the control rights to the small firm may be sometimes desirable but not feasible. The performance of 200 agreements entered into by biotechnology firms between 1980 and 1995 suggests that financing availability does matter. Consistent with theory, agreements signed during periods with little external equity financing that assign the bulk of the control to the corporate partner are significantly less successful than other alliances. These agreements are also disproportionately likely to be renegotiated if financial market conditions improve.