Relaxation measurements in the regime of the second magnetization peak in Nb films

We report on magnetic measurements as a function of field, temperature and time (relaxation) in superconducting Nb films of critical temperature Tc = 9.25 K. The magnetic measurements as a function of field exhibited a second magnetization peak (SMP) which in general is accompanied by thermomagnetic instabilities (TMIs). The lines where the SMP occurs and where the first flux jump in the virgin magnetization curves is observed, end at a characteristic point (To,Ho)=(7.2 K,80 Oe). Relaxation measurements showed that for T<To=7.2 K the activation energy Uo and the normalized relaxation rate S exhibit non-monotonic behavior as a function either of temperature or field. The extrema observed in Uo and S coincide with the onset and the maximum points of the SMP. In the regime T>To=7.2 K both Uo and S present a conventional monotonic behavior. These results indicate that the SMP behavior observed in our Nb films is promoted by the anomalous relaxation of the magnetization.Comment: To appear in Physica

Neonatal-derived IL-17 producing dermal gammadelta T cells are required to prevent spontaneous atopic dermatitis

Atopic Dermatitis (AD) is a T cell-mediated chronic skin disease and is associated with altered skin barrier integrity. Infants with mutations in genes involved in tissue barrier fitness are predisposed towards inflammatory diseases, but most do not develop or sustain the diseases, suggesting that there exist regulatory immune mechanisms to prevent aberrant inflammation. The absence of one single murine dermal cell type, the innate neonatal-derived IL-17 producing gammadelta T (Tgammadelta17) cells, from birth resulted in spontaneous, highly penetrant AD with many of the major hallmarks of human AD. In Tgammadelta17 cell-deficient mice, basal keratinocyte transcriptome was altered months in advance of AD induction. Tgammadelta17 cells respond to skin commensal bacteria and the fulminant disease in their absence was driven by skin commensal bacteria dysbiosis. AD in this model was characterized by highly expanded dermal alphabeta T clonotypes that produce the type three cytokines, IL-17 and IL-22. These results demonstrate that neonatal Tgammadelta17 cells are innate skin regulatory T cells that are critical for skin homeostasis, and that IL-17 has dual homeostatic and inflammatory function in the skin

Squark and Gluino Production with Jets

We present cross section predictions for squark and gluino production at the LHC, in association with up to two additional hard jets. These cross sections can be very large in comparison to the inclusive Born rates. Because hadron collider experiments utilize hard jets in the reconstruction of cascade decays or as a way to separate squark and gluino production, the understanding of these processes is crucial. We show to what degree hard jet radiation can be described by shower algorithms and point out how tuning these showers, for example to top quark pair production, could help reduce theoretical uncertainties for new physics searches at the LHC.Comment: 5 p, 2 fig, 1 tab; version to appear in PLB; added comments on uncertainty estimate

Combining QCD Matrix Elements at Next-to-Leading Order with Parton Showers in Electroproduction

We present a method to combine next-to-leading order (NLO) matrix elements in QCD with leading logarithmic parton showers by applying a suitably modified version of the phase-space-slicing method. The method consists of subsuming the NLO corrections into a scale-dependent phase-space-slicing parameter, which is then automatically adjusted to cut out the leading order, virtual, soft and collinear contributions in the matrix element calculation. In this way a positive NLO weight is obtained, which can be redistributed by a parton shower algortihm. As an example, we display the method for single-jet inclusive cross sections at O(alpha_s) in electroproduction. We numerically compare the modified version of the phase-space-slicing method with the standard approach and find very good agreement on the percent level.Comment: 21 pages, 2 eps figures. Revised section 2. To appear in PR

Vortex Fluctuations in High-Tc Films: Flux Noise Spectrum and Complex Impedance

The flux noise spectrum and complex impedance for a 500 {\AA} thick YBCO film are measured and compared with predictions for two dimensional vortex fluctuations. It is verified that the complex impedance and the flux noise spectra are proportional to each other, that the logarithm of the flux noise spectra for different temperatures has a common tangent with slope $\approx -1$, and that the amplitude of the noise decreases as $d^{-3}$, where $d$ is the height above the film at which the magnetic flux is measured. A crossover from normal to anomalous vortex diffusion is indicated by the measurements and is discussed in terms of a two-dimensional decoupling.Comment: 5 pages including 4 figures in two columns, to appear in Phys. Rev. Let

Sustained activation of the unfolded protein response induces cell death in Fuchs' endothelial corneal dystrophy

Purpose: The unfolded protein response (UPR) is believed to play a role in the pathogenesis of Fuchs' endothelial corneal dystrophy (FECD). The purpose of this study was to investigate whether unfolded proteins accumulate in the corneal endothelium in FECD and if they are involved in triggering cell death. Methods: Descemet's membranes with corneal endothelial cells (CECs) were obtained during keratoplasty, and expression of aggresomes, type 1 collagen, fibronectin, and agrin was evaluated. Endoplasmic reticulum (ER) stress of immortalized human CECs from non-FECD subjects and from FECD patients (iHCEC and iFECD, respectively) were evaluated. The effect of MG132-mediated aggresome formation on the UPR and intrinsic pathway and the effect of mitochondrial damage on UPR were also examined. The effect of CHOP knockdown on the ER stress–mediated intrinsic pathway was also evaluated. Results: Aggresome formation was higher in iFECD than in iHCEC and was colocalized with type 1 collagen, fibronectin, and agrin. GRP78, phosphorylated IRE1, PERK, and CHOP showed higher activation in iFECD than in iHCEC. MG132-mediated aggresome formation upregulated ER stress sensors, the mitochondrial membrane potential drop, cytochrome c release to the cytoplasm, and activation of caspase-9 and -3. By contrast, staurosporine-mediated mitochondrial damage did not induce ER stress. Knockdown of CHOP attenuated the ER stress-induced cleavage of caspase-9, which is caused by intrinsic pathway activation. Conclusions: Excessive synthesis of extracellular matrix proteins induced unfolded protein accumulation in FECD. Prolonged ER stress–mediated cell death, occurring via the intrinsic apoptotic signaling pathway, therefore might be associated with the pathogenesis of FECD