Melvin universe as a limit of the C-metric

It is demonstrated that the Melvin universe representing the spacetime with a strong 'homogeneous' electric field can by obtained from the spacetime of two accelerated charged black holes by a suitable limiting procedure. The behavior of various invariantly defined geometrical quantities in this limit is also studied.Comment: 5 pages, no figures [v2: two references added

An Efficient 2-Party Private Function Evaluation Protocol Based on Half Gates

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Private function evaluation (PFE) is a special case of secure multi-party computation (MPC), where the function to be computed is known by only one party. PFE is useful in several real-life applications where an algorithm or a function itself needs to remain secret for reasons such as protecting intellectual property or security classification level. In this paper, we focus on improving 2-party PFE based on symmetric cryptographic primitives. In this respect, we look back at the seminal PFE framework presented by Mohassel and Sadeghian at Eurocrypt’13. We show how to adapt and utilize the well-known half gates garbling technique (Zahur et al., Eurocrypt’15) to their constant-round 2-party PFE scheme. Compared to their scheme, our resulting optimization significantly improves the efficiency of both the underlying Oblivious Evaluation of Extended Permutation (OEP) and secure 2-party computation (2PC) protocols, and yields a more than 40% reduction in overall communication cost (the computation time is also slightly decreased and the number of rounds remains unchanged)

Object memory effects on figure assignment:conscious object recognition in not necessary or sufficient

AbstractIn three experiments we investigated whether conscious object recognition is necessary or sufficient for effects of object memories on figure assignment. In experiment 1, we examined a brain-damaged participant, AD, whose conscious object recognition is severely impaired. AD’s responses about figure assignment do reveal effects from memories of object structure, indicating that conscious object recognition is not necessary for these effects, and identifying the figure-ground test employed here as a new implicit test of access to memories of object structure. In experiments 2 and 3, we tested a second brain-damaged participant, WG, for whom conscious object recognition was relatively spared. Nevertheless, effects from memories of object structure on figure assignment were not evident in WG’s responses about figure assignment in experiment 2, indicating that conscious object recognition is not sufficient for effects of object memories on figure assignment. WG’s performance sheds light on AD’s performance, and has implications for the theoretical understanding of object memory effects on figure assignment

Ferrohydrodynamics: testing a new magnetization equation

A new magnetization equation recently derived from irreversible thermodynamics is employed to the calculation of an increase of ferrofluid viscosity in a magnetic field. Results of the calculations are compared with those obtained on the basis of two well-known magnetization equations. One of the two was obtained phenomenologically, another one was derived microscopically from the Fokker-Planck equation. It is shown that the new magnetization equation yields a quite satisfactory description of magnetiviscosity in the entire region of magnetic field strength and the flow vorticity. This equation turns out to be valid -- like the microscopically derived equation but unlike the former phenomenological equation -- even far from equilibrium, and so it should be recommended for further applications.Comment: 4 pages, 3 figures, Submitted to Phys. Rev.

Inorganic phosphate modulates the expression of the NaPi-2a transporter in the trans -golgi network and the interaction with PIST in the proximal tubule

Inorganic phosphate (Pi) homeostasis is maintained by the tight regulation of renal Pi excretion versus reabsorption rates that are in turn modulated by adjusting the number of Pi transporters (mainly NaPi-2a) in the proximal tubules. In response to some hormones and a high dietary Pi content, NaPi-2a is endocytosed and degraded in the lysosomes; however, we show here that some NaPi-2amolecules are targeted to the trans-Golgi network (TGN) during the endocytosis. In the TGN, NaPi-2a interacts with PIST (PDZ-domain protein interacting specifically with TC10), a TGN-resident PDZ-domain-containing protein. The extension of the interaction is proportional to the expression of NaPi-2a in the TGN, and, consistent with that, it is increased with a high Pi diet. When overexpressed in opossum kidney (OK) cells, PIST retains NaPi-2a in the TGN and inhibits Na-dependent Pi transport. Overexpression of PIST also prevents the adaptation of OK cells to a low Pi culture medium. Our data supports the view that NaPi-2a is subjected to retrograde trafficking from the plasma membrane to the TGN using one of the machineries involved in endosomal transport and explains the reported expression of NaPi-2a in the TGN

Gauged Dimension Bubbles

Some of the peculiar electrodynamical effects associated with gauged ``dimension bubbles'' are presented. Such bubbles, which effectively enclose a region of 5d spacetime, can arise from a 5d theory with a compact extra dimension. Bubbles with thin domain walls can be stabilized against total collapse by the entrapment of light charged scalar bosons inside the bubble, extending the idea of a neutral dimension bubble to accommodate the case of a gauged U(1) symmetry. Using a dielectric approach to the 4d dilaton-Maxwell theory, it is seen that the bubble wall is almost totally opaque to photons, leading to a new stabilization mechanism due to trapped photons. Photon dominated bubbles very slowly shrink, resulting in a temperature increase inside the bubble. At some critical temperature, however, these bubbles explode, with a release of radiation.Comment: 14 pages, no figures; to appear in Phys.Rev.

Beneficial effects of conversion from cyclosporine to azathioprine on fibrinolysis in renal transplant recipients

Cyclosporin A (CsA) has been implicated as one of the factors contributing to the high cardiovascular morbidity and mortality after renal transplantation. This may be mediated by either a high prevalence of conventional risk factors for atherosclerosis, such as hypertension, hypercholesterolemia, and diabetes mellitus, or by impairment of the fibrinolytic activity evoked by CsA, possibly through interference with prostanoid metabolism. We therefore assessed the impact of conversion of CsA to azathioprine immunosuppressive treatment on parameters of fibrinolytic activity and plasma concentration of the prostanoids prostaglandin E2 and thromboxane B2 in 18 stable renal transplant recipients. During CsA, mean arterial pressure and serum creatinine were significantly higher than during azathioprine (116+/-15 mm Hg versus 106+/-13 mm Hg, P=0.0003; and 147+/-34 micromol/L versus 127+/-35 micromol/L, P=0.002; mean+/-SD). On conversion, the plasma tissue plasminogen activator activity increased from 1.2 (1.1 to 1.7; median, 95% CI) to 1.8 (1.6 to 2.0) IU/mL (P=0.011), without a significant change of the plasminogen activator antigen concentration. This was associated with a substantial decrease in plasminogen activator inhibitor-1 activity from 10.4 (8.5 to 16.7) to 6.4 (5.6 to 9.2) IU/mL (P=0.009). Furthermore, plasma levels of prostaglandin E2 and thromboxane B2 markedly decreased (from 9.7 [7.4 to 12.9] to 4.6 [4.3 to 8.1] pg/mL, P=0.0006; and from 106.1 [91.7 to 214.2] to 70.2 [50.3 to 85.6] pg/mL, P=0.002, respectively). During CsA, but not azathioprine, plasma tissue plasminogen activator antigen and plasminogen activator inhibitor-1 levels correlated significantly with prostaglandin E2 (r=0.53, P=0.02; and r=0.60, P=0.008, respectively), and thromboxane B2 (r=0.75, P=0.0001; and r=0.77, P=0.0001, respectively) levels. In conclusion, CsA induced substantial impairment of fibrinolytic activity, which recovered after conversion to azathioprine. The impaired fibrinolysis observed during CsA treatment may be caused by modulation of eicosanoid production or metabolism in vascular endothelial cells and possibly contributes to the high incidence of cardiovascular disease after kidney transplantation

Comment on "Magnetoviscosity and relaxation in ferrofluids"

It is shown and discussed how the conventional system of hydrodynamic equations for ferrofluids was derived. The set consists of the equation of fluid motion, the Maxwell equations, and the magnetization equation. The latter was recently revised by Felderhof [Phys. Rev. E, v.62, p.3848 (2000)]. His phenomenological magnetization equation looks rather like corresponding Shliomis' equation, but leads to wrong consequences for the dependence of ferrofluid viscosity and magnetization relaxation time on magnetic field.Comment: 6 pages, 1 figure, Submitted to Phys. Rev.

Data Mining Approaches to Diffuse Large B–Cell Lymphoma Gene Expression Data Interpretation

This paper presents a comprehensive study of gene expression patterns originating from a diffuse large B–cell lymphoma (DLBCL) database. It focuses on the implementation of feature selection and classification techniques. Thus, it firstly tackles the identification of relevant genes for the prediction of DLBCL types. It also allows the determination of key biomarkers to differentiate two subtypes of DLBCL samples: Activated B–Like and Germinal Centre B–Like DLBCL. Decision trees provide knowledge–based models to predict types and subtypes of DLBCL. This research suggests that the data may be insufficient to accurately predict DLBCL types or even detect functionally relevant genes. However, these methods represent reliable and understandable tools to start thinking about possible interesting non–linear interdependencies