Quantum Correlations in Multipartite Quantum Systems

We review some concepts and properties of quantum correlations, in particular multipartite measures, geometric measures and monogamy relations. We also discuss the relation between classical and total correlationsComment: to be published as a chapter of the book "Lectures on general quantum correlations and their applications" edited by F. Fanchini, D. Soares-Pinto, and G. Adesso (Springer, 2017

Job Strain, Health and Sickness Absence: Results from the Hordaland Health Study

MW and SBH are funded by NSW Health. M. Henderson and M. Hotopf were supported by the NIHR Biomedical Research Centre for Mental Health at the South London and Maudsley NHS Foundation Trust and Institute of Psychiatry, King’s College London. AM and SO were funded by the Norwegian Research Council

Surface Chemistry of Perfluoropolyethers and Hydrogenated Analogs: Are Studies of Model Compounds Useful?

We have studied adsorption, desorption, and decomposition of ethers on Ru(001), an atomically-smooth metal surface. We have compared diethers with monoethers, and fluorinated ethers with hydrogenated ethers. The number of ether linkages does not strongly influence adsorption bond strength, nor the extent of decomposition. Fluorination does weaken the adsorption bond strength and prevents decomposition. These studies suggest that the surface properties of monomeric ethers can be used to predict properties of oligomeric, and perhaps even polymeric, ethers

Treatment for lupus nephritis

BackgroundCyclophosphamide, in combination with corticosteroids has been used to induce remission in proliferative lupus nephritis, the most common kidney manifestation of the multisystem disease, systemic lupus erythematosus. Cyclophosphamide therapy has reduced mortality from over 70% in the 1950s and 1960s to less than 10% in recent years. Cyclophosphamide combined with corticosteroids preserves kidney function but is only partially effective and may cause ovarian failure, infection and bladder toxicity. Several new agents, including mycophenolate mofetil (MMF), suggest reduced toxicity with equivalent rates of remission. This is an update of a Cochrane review first published in 2004.ObjectivesTo assess the benefits and harms of different immunosuppressive treatments in biopsy-proven proliferative lupus nephritis.Search methodsFor this update, we searched the Cochrane Renal Group's Specialised Register (up to 15 April 2012) through contact with the Trials' Search Coordinator using search terms relevant to this review.Selection criteriaRandomised controlled trials (RCTs) and quasi-RCTs comparing any treatments for biopsy-proven lupus nephritis in both adult and paediatric patients with class III, IV, V + III and V + IV lupus nephritis were included. All immunosuppressive treatments were considered.Data collection and analysisData were abstracted and quality assessed independently by two authors, with differences resolved by discussion. Dichotomous outcomes were reported as risk ratio (RR) and measurements on continuous scales reported as mean differences (MD) with 95% confidence intervals (CI).Main resultsWe identified 50 RCTs involving 2846 participants. Of these, 45 studies (2559 participants) investigated induction therapy, and six studies (514 participants), considered maintenance therapy.Compared with intravenous (IV) cyclophosphamide, MMF was as effective in achieving stable kidney function (5 studies, 523 participants: RR 1.05, 95% CI 0.94 to 1.18) and complete remission of proteinuria (6 studies, 686 participants: RR 1.16, 95% CI 0.85 to 1.58). No differences in mortality (7 studies, 710 participants: RR 1.02, 95% CI 0.52 to 1.98) or major infection (6 studies, 683 participants: RR 1.11, 95% CI 0.74 to 1.68) were observed. A significant reduction in ovarian failure (2 studies, 498 participants: RR 0.15, 95% CI 0.03 to 0.80) and alopecia (2 studies, 522 participants: RR 0.22, 95% CI 0.06 to 0.86) was observed with MMF. In maintenance therapy, the risk of renal relapse (3 studies, 371 participants: RR 1.83, 95% CI 1.24 to 2.71) was significantly higher with azathioprine compared with MMF. Multiple other interventions were compared but outcome data were relatively sparse. Overall study quality was variable. The internal validity of the design, conduct and analysis of the included RCTs was difficult to assess in some studies because of the omission of important methodological details. No study adequately reported all domains of the risk of bias assessment so that elements of internal bias may be present.Authors' conclusionsMMF is as effective as cyclophosphamide in inducing remission in lupus nephritis, but is safer with a lower risk of ovarian failure. MMF is more effective than azathioprine in maintenance therapy for preventing relapse with no increase in clinically important side effects. Adequately powered trials with long term follow-up are required to more accurately define the risks and eventual harms of specific treatment regimens

CD98hc facilitates B cell proliferation and adaptive humoral immunity.

The proliferation of antigen-specific lymphocytes and resulting clonal expansion are essential for adaptive immunity. We report here that B cell-specific deletion of the heavy chain of CD98 (CD98hc) resulted in lower antibody responses due to total suppression of B cell proliferation and subsequent plasma cell formation. Deletion of CD98hc did not impair early B cell activation but did inhibit later activation of the mitogen-activated protein kinase Erk1/2 and downregulation of the cell cycle inhibitor p27. Reconstitution of CD98hc-deficient B cells with CD98hc mutants showed that the integrin-binding domain of CD98hc was required for B cell proliferation but that the amino acid-transport function of CD98hc was dispensable for this. Thus, CD98hc supports integrin-dependent rapid proliferation of B cells. We propose that the advantage of adaptive immunity favored the appearance of CD98hc in vertebrates

Undular tidal bores: Effect of channel constriction and bridge piers

A tidal bore may occur in a macro-tidal estuary when the tidal range exceeds 4.5-6 m and the estuary bathymetry amplifies the tidal wave. Its upstream propagation induces a strong mixing of the estuarine waters. The propagation of undular tidal bores was investigated herein to study the effect of bridge piers on the bore propagation and characteristics. Both the tidal bore profile and the turbulence generated by the bore were recorded. The free-surface undulation profiles exhibited a quasi-periodic shape, and the potential energy of the undulations represented up to 30% of the potential energy of the tidal bore. The presence of the channel constriction had a major impact on the free-surface properties. The undular tidal bore lost nearly one third of its potential energy per surface area as it propagated through the channel constriction. The detailed instantaneous velocity measurements showed a marked effect of the tidal bore passage suggesting the upstream advection of energetic events and vorticity "clouds" behind the bore front in both channel configurations: prismatic and with constriction. The turbulence patches were linked to some secondary motions and the proposed mechanisms were consistent with some field observations in the Daly River tidal bore. The findings emphasise the strong mixing induced by the tidal bore processes, and the impact of bridge structures on the phenomenon. © 2010 Springer Science+Business Media B.V

Frozen and Invariant Quantum Discord under Local Dephasing Noise

In this chapter, we intend to explore and review some remarkable dynamical properties of quantum discord under various different open quantum system models. Specifically, our discussion will include several concepts connected to the phenomena of time invariant and frozen quantum discord. Furthermore, we will elaborate on the relation of these two phenomena to the non-Markovian features of the open system dynamics and to the usage of dynamical decoupling protocols.Comment: 29 pages, 8 figure

The sudden change phenomenon of quantum discord

Even if the parameters determining a system's state are varied smoothly, the behavior of quantum correlations alike to quantum discord, and of its classical counterparts, can be very peculiar, with the appearance of non-analyticities in its rate of change. Here we review this sudden change phenomenon (SCP) discussing some important points related to it: Its uncovering, interpretations, and experimental verifications, its use in the context of the emergence of the pointer basis in a quantum measurement process, its appearance and universality under Markovian and non-Markovian dynamics, its theoretical and experimental investigation in some other physical scenarios, and the related phenomenon of double sudden change of trace distance discord. Several open questions are identified, and we envisage that in answering them we will gain significant further insight about the relation between the SCP and the symmetry-geometric aspects of the quantum state space.Comment: Lectures on General Quantum Correlations and their Applications, F. F. Fanchini, D. O. Soares Pinto, and G. Adesso (Eds.), Springer (2017), pp 309-33

Experimental study of a positive surge. Part 1: Basic flow patterns and wave attenuation

A positive surge results from a sudden change in flow that increases the depth. It is the unsteady flow analogy of the stationary hydraulic jump and a geophysical application is the tidal bore. Positive surges are commonly studied using the method of characteristics and the Saint-Venant equations. The paper presents the results from new experimental investigations conducted in a large rectangular channel. Detailed unsteady velocity measurements were performed with a high temporal resolution using acoustic Doppler velocimetry and non-intrusive free-surface measurement devices. Several experiments were conducted with the same initial discharge (Q=0.060 m³/s) and 6 different gate openings after closure resulting in both non-breaking undular and breaking bores. The analysis of undular surges revealed wave amplitude attenuation with increasing distance of surge propagation were in agreement with Ippen and Kulin theory. Also, undular wave period and wave length data were relatively close to the values predicted by the wave dispersion theory for gravity waves in intermediate water depths

Turbulence and aeration in hydraulic jumps: free-surface fluctuation and integral turbulent scale measurements

In an open channel, a change from a supercritical to subcritical flow is a strong dissipative process called a hydraulic jump. Herein some new measurements of free-surface fluctuations of the impingement perimeter and integral turbulent time and length scales in the roller are presented with a focus on turbulence in hydraulic jumps with a marked roller. The observations highlighted the fluctuating nature of the impingement perimeter in terms of both longitudinal and transverse locations. The results showed further the close link between the production and detachment of large eddies in jump shear layer, and the longitudinal fluctuations of the jump toe. They highlighted the importance of the impingement perimeter as the origin of the developing shear layer and a source of vorticity. The air–water flow measurements emphasised the intense flow aeration. The turbulent velocity distributions presented a shape similar to a wall jet solution with a marked shear layer downstream of the impingement point. The integral turbulent length scale distributions exhibited a monotonic increase with increasing vertical elevation within 0.2 < Lz/d1 < 0.8 in the shear layer, where Lz is the integral turbulent length scale and d1 the inflow depth, while the integral turbulent time scales were about two orders of magnitude smaller than the period of impingement position longitudinal oscillations