Fractional Kinetics for Relaxation and Superdiffusion in Magnetic Field

We propose fractional Fokker-Planck equation for the kinetic description of relaxation and superdiffusion processes in constant magnetic and random electric fields. We assume that the random electric field acting on a test charged particle is isotropic and possesses non-Gaussian Levy stable statistics. These assumptions provide us with a straightforward possibility to consider formation of anomalous stationary states and superdiffusion processes, both properties are inherent to strongly non-equilibrium plasmas of solar systems and thermonuclear devices. We solve fractional kinetic equations, study the properties of the solution, and compare analytical results with those of numerical simulation based on the solution of the Langevin equations with the noise source having Levy stable probability density. We found, in particular, that the stationary states are essentially non-Maxwellian ones and, at the diffusion stage of relaxation, the characteristic displacement of a particle grows superdiffusively with time and is inversely proportional to the magnetic field.Comment: 15 pages, LaTeX, 5 figures PostScrip

Analysis of the Rosenblatt process

We analyze {\em the Rosenblatt process} which is a selfsimilar process with stationary increments and which appears as limit in the so-called {\em Non Central Limit Theorem} (Dobrushin and Major (1979), Taqqu (1979)). This process is non-Gaussian and it lives in the second Wiener chaos. We give its representation as a Wiener-It\^o multiple integral with respect to the Brownian motion on a finite interval and we develop a stochastic calculus with respect to it by using both pathwise type calculus and Malliavin calculus

Deformation transfer survey

Deformation transfer is a type of retargeting method that operates directly on the mesh and, by doing so, enables reuse of animation without setting up character rigs and a mapping between the source and target geometries. Deformation transfer can potentially reduce the costs of animation and give studios a competitive edge when keeping up with the latest computer animation technology. Unfortunately, deformation transfer has limitations and is yet to become standard practice in the industry. This survey starts by introducing Sumner and Popović’s [18] seminal work and highlights key issues for industry settings. We then review related work in sections, organized by these key issues. After surveying related work, we discuss how their advances open the door to several practical applications of deformation transfer. To conclude, we highlight areas of future work

The Off State of GX 339-4

We report BeppoSAX and optical observations of the black hole candidate GX 339-4 during its X-ray `off' state in 1999. The broad-band (0.8-50 keV) X-ray emission can be fitted by a single power law with spectral index, \alpha ~1.6. The observed luminosity is 6.6e33 erg s^{-1} in the 0.5-10 keV band, which is at the higher end of the flux distribution of black hole soft X-ray transients in quiescence, comparable to that seen in GS 2023+338 and 4U 1630-47. An optical observation just before the BeppoSAX observation shows the source to be very faint at these wavelengths as well (B=20.1, V=19.2). By comparing with previously reported `off' and low states (LS), we conclude that the `off' state is actually an extension of the LS, i.e. a LS at lower intensities. We propose that accretion models such as the advection-dominated accretion flows are able to explain the observed properties in such a state.Comment: Accepted for publication in MNRA

Broad-band X-ray spectral evolution of GX 339-4 during a state transition

We report on X-ray and soft gamma-ray observations of the black-hole candidate GX 339-4 during its 2007 outburst, performed with the RXTE and INTEGRAL satellites. The hardness-intensity diagram of all RXTE/PCA data combined shows a q-shaped track similar to that observed in previous outbursts.The evolution in the diagram suggested that a transition from hard-intermediate state to soft-intermediate state occurred, simultaneously with INTEGRAL observations performed in March. The transition is confirmed by the timing analysis presented in this work, which reveals that a weak type-A quasi-periodic oscillation (QPO) replaces a strong type-C QPO. At the same time, spectral analysis shows that the flux of the high-energy component shows a significant decrease in its flux. However, we observe a delay (roughly one day) between variations of the spectral parameters of the high-energy component and changes in the flux and timing properties. The changes in the high-energy component can be explained either in terms the high-energy cut-off or in terms of a variations in the reflection component. We compare our results with those from a similar transition during the 2004 outburst of GX 339-4.Comment: 8 pages, 6 figures, accepted for publication in MNRAS Main Journa

Increased S-nitrosylation and proteasomal degradation of caspase-3 during infection contribute to the persistence of adherent invasive escherichia coli (AIEC) in immune cells

Adherent invasive Escherichia coli (AIEC) have been implicated as a causative agent of Crohn's disease (CD) due to their isolation from the intestines of CD sufferers and their ability to persist in macrophages inducing granulomas. The rapid intracellular multiplication of AIEC sets it apart from other enteric pathogens such as Salmonella Typhimurium which after limited replication induce programmed cell death (PCD). Understanding the response of infected cells to the increased AIEC bacterial load and associated metabolic stress may offer insights into AIEC pathogenesis and its association with CD. Here we show that AIEC persistence within macrophages and dendritic cells is facilitated by increased proteasomal degradation of caspase-3. In addition S-nitrosylation of pro- and active forms of caspase-3, which can inhibit the enzymes activity, is increased in AIEC infected macrophages. This S-nitrosylated caspase-3 was seen to accumulate upon inhibition of the proteasome indicating an additional role for S-nitrosylation in inducing caspase-3 degradation in a manner independent of ubiquitination. In addition to the autophagic genetic defects that are linked to CD, this delay in apoptosis mediated in AIEC infected cells through increased degradation of caspase-3, may be an essential factor in its prolonged persistence in CD patients

Serotonin neurons in the dorsal raphe mediate the anticataplectic action of orexin neurons by reducing amygdala activity

Narcolepsy is a sleep disorder caused by the loss of orexin (hypocretin)-producing neurons and marked by excessive daytime sleepiness and a sudden weakening of muscle tone, or cataplexy, often triggered by strong emotions. In a mouse model for narcolepsy, we previously demonstrated that serotonin neurons of the dorsal raphe nucleus (DRN) mediate the suppression of cataplexy-like episodes (CLEs) by orexin neurons. Using an optogenetic tool, in this paperwe show that the acute activation of DRN serotonin neuron terminals in the amygdala, but not in nuclei involved in regulating rapid eye-movement sleep and atonia, suppressed CLEs. Not only did stimulating serotonin nerve terminals reduce amygdala activity, but the chemogenetic inhibition of the amygdala using designer receptors exclusively activated by designer drugs also drastically decreased CLEs, whereas chemogenetic activation increased them. Moreover, the optogenetic inhibition of serotonin nerve terminals in the amygdala blocked the anticataplectic effects of orexin signaling in DRN serotonin neurons. Taken together, the results suggest that DRN serotonin neurons, as a downstream target of orexin neurons, inhibit cataplexy by reducing the activity of amygdala as a center for emotional processing

Protection by the NO-Donor SNAP and BNP against Hypoxia/Reoxygenation in Rat Engineered Heart Tissue

In vitro assays could replace animal experiments in drug screening and disease modeling, but have shortcomings in terms of functional readout. Force-generating engineered heart tissues (EHT) provide simple automated measurements of contractile function. Here we evaluated the response of EHTs to hypoxia/reoxygenation (H/R) and the effect of known cardiocytoprotective molecules. EHTs from neonatal rat heart cells were incubated for 24 h in EHT medium. Then they were subjected to 180 min hypoxia (93% N2, 7% CO2) and 120 min reoxygenation (40% O2, 53% N2, 7% CO2), change of medium and additional follow-up of 48 h. Time-matched controls (40% O2, 53% N2, 7% CO2) were run for comparison. The following conditions were applied during H/R: fresh EHT medium (positive control), the NO-donor S-nitroso-N-acetyl-D,L-penicillamine (SNAP, 10-7, 10-6, 10-5 M) or the guanylate cyclase activator brain type natriuretic peptide (BNP, 10-9, 10-8, 10-7 M). Frequency and force of contraction were repeatedly monitored over the entire experiment, pH, troponin I (cTnI), lactate dehydrogenase (LDH) and glucose concentrations measured in EHT medium. Beating activity of EHTs in 24 h-medium ceased during hypoxia, partially recovered during reoxygenation and reached time-control values during follow-up. H/R was accompanied by a small increase in LDH and non-significant increase in cTnI. In fresh medium, some EHTs continued beating during hypoxia and all EHTs recovered faster during reoxygenation. SNAP and BNP showed small but significant protective effects during reoxygenation. EHTs are applicable to test potential cardioprotective compounds in vitro, monitoring functional and biochemical endpoints, which otherwise could be only measured by using in vivo or ex vivo heart preparations. The sensitivity of the model needs improvement