Ergodic Randomized Algorithms and Dynamics over Networks

Algorithms and dynamics over networks often involve randomization, and randomization may result in oscillating dynamics which fail to converge in a deterministic sense. In this paper, we observe this undesired feature in three applications, in which the dynamics is the randomized asynchronous counterpart of a well-behaved synchronous one. These three applications are network localization, PageRank computation, and opinion dynamics. Motivated by their formal similarity, we show the following general fact, under the assumptions of independence across time and linearities of the updates: if the expected dynamics is stable and converges to the same limit of the original synchronous dynamics, then the oscillations are ergodic and the desired limit can be locally recovered via time-averaging.Comment: 11 pages; submitted for publication. revised version with fixed technical flaw and updated reference

On the nature of V2282 Sgr

The star V2282 Sgr is positionally consistent with a strong Chandra X-ray and a Spitzer/IRAC MIR source. We derived its long term $I$-band light curve from the photographic archives of the Asiago and Catania Observatories, covering the years from 1965 to 1984. CCD $R_C$ photometry in Summer 2009 was re-analyzed. Optical spectra were secured at Loiano Observatory in 2011 and 2012. J H K photometry, obtained from several experiments in different epochs was compared and the Spitzer images were re-analyzed. V2282 Sgr was found to be irregular variable in all wavelengths. Spectroscopically, it shows strong emission features (H Balmer lines, [NII]6584 AA and [OIII]5007/4959 AA) while the Na D doublet is very strong, indicating a circumstellar envelope. A single thermal energy distribution cannot reproduce the observed SED, while it can be explained as the sum of a G-type star plus a variable circumstellar disc, which mimics a class 0/I object. Most likely, V2282 Sgr is a 1-2 $M_{sun}$ mass pre main sequence star with an accretion disk.Comment: 13 pages, 7 figure, in press on Baltic Astronom

A method for narrow-band searches of continuous gravitational wave signals

Targeted searches of continuous waves from spinning neutron stars normally assume that the frequency of the gravitational wave signal is at a given known ratio with respect to the rotational frequency of the source, e.g. twice for an asymmetric neutron star rotating around a principal axis of inertia. In fact this assumption may well be invalid if, for instance, the gravitational wave signal is due to a solid core rotating at a slightly different rate with respect to the star crust. In this paper we present a method for {\it narrow-band} searches of continuous gravitational wave signals from known pulsars in the data of interferometric detectors. This method assumes source position is known to high accuracy, while a small frequency and spin-down range around the electromagnetic-inferred values is explored. Barycentric and spin-down corrections are done with an efficient time-domain procedure. Sensitivity and computational efficiency estimates are given and results of tests done using simulated data are also discussed.Comment: 13 pages; 6 figures; accepted in PR

CD3+CD4+LAP+Foxp3-regulatory cells of the colonic lamina propria limit disease extension in ulcerative colitis

Background and Aims: In ulcerative colitis (UC), inflammation begins in the rectum and can extend proximally throughout the entire colon. The extension of inflammation is an important determinant of disease course, and may be limited by the action of regulatory T cells (Tregs). In this cross-sectional study, we evaluated the relationship between UC extension and the proportions of CD3+CD4+Foxp3+ and CD3+CD4+LAP+Foxp3- Tregs in the colonic lamina propria (LP) of 79 UC patients and 29 controls. The role of these cells in UC extension was also investigated in the murine oxazolone-induced colitis model. Methods: Patients: Disease extension was classified according to the Montreal classification. Where possible, endoscopic biopsies of involved and uninvolved tissue were obtained from UC patients. Mouse model: Colitis was induced by intrarectal oxazolone administration. Lamina propria mononuclear cells were isolated from patient biopsies and mouse colon tissue using enzymatic method and the percentage of CD3+CD4+Foxp3+ and CD3+CD4+LAP+Foxp3-cells evaluated by immunofluorescence. Confocal microscopy was applied for the visualization and quantification of CD4+LAP+ cells on tissue histological sections. Results: In UC patients with distal colitis the proportion of LP CD3+CD4+Foxp3+ Tregs was significantly higher in inflamed tissue than uninvolved tissue. As opposite, the proportion of LP CD3+CD4+LAP+ Tregs was significantly higher in uninvolved tissue than involved tissue. Both LP CD3+CD4+Foxp3+ and LP CD3+CD4+LAP+ Tregs proportion in involved tissue was significantly higher than in controls irrespective of the extension of inflammation. In mice with oxazolone-induced distal colitis, treatment with LAP-depleting antibody was associated with the development of extensive colitis. Conclusions: Our findings suggest that CD3+CD4+LAP+Foxp3-Tregs limit the extension of inflammatory lesions in UC patients

Overlapping, Additive and Counterregulatory Effects of Type II and I Interferons on Myeloid Dendritic Cell Functions

Dendritic cells (DCs) are central player in immunity by bridging the innate and adaptive arms of the immune system (IS). Interferons (IFNs) are one of the most important factors that regulate both innate and adaptive immunity too. Thus, the understanding of how type II and I IFNs modulate the immune-regulatory properties of DCs is a central issue in immunology. In this paper, we will address this point in the light of the most recent literature, also highlighting the controversial data reported in the field. According to the wide literature available, type II as well as type I IFNs appear, at the same time, to collaborate, to induce additive effects or overlapping functions, as well as to counterregulate each one's effects on DC biology and, in general, the immune response. The knowledge of these effects has important therapeutic implications in the treatment of infectious/autoimmune diseases and cancer and indicates strategies for using IFNs as vaccine adjuvants and in DC-based immune therapeutic approaches

Liquid-crystalline ordering of antimicrobial peptide-DNA complexes controls TLR9 activation.

Double-stranded DNA (dsDNA) can trigger the production of type I interferon (IFN) in plasmacytoid dendritic cells (pDCs) by binding to endosomal Toll-like receptor-9 (TLR9; refs 1-5). It is also known that the formation of DNA-antimicrobial peptide complexes can lead to autoimmune diseases via amplification of pDC activation. Here, by combining X-ray scattering, computer simulations, microscopy and measurements of pDC IFN production, we demonstrate that a broad range of antimicrobial peptides and other cationic molecules cause similar effects, and elucidate the criteria for amplification. TLR9 activation depends on both the inter-DNA spacing and the multiplicity of parallel DNA ligands in the self-assembled liquid-crystalline complex. Complexes with a grill-like arrangement of DNA at the optimum spacing can interlock with multiple TLR9 like a zipper, leading to multivalent electrostatic interactions that drastically amplify binding and thereby the immune response. Our results suggest that TLR9 activation and thus TLR9-mediated immune responses can be modulated deterministically.This work is supported by NSF grants DMR1411329 and DMR1106106, EU grants ARG-ERC-COLSTRUCTION 227758 and ITN-COMPLOIDS 234810, by the Herchel Smith Fund, and by the Slovenian Research Agency through Grant P1-0055, and the Swiss National Science Foundation (FN 310030-144072). X-ray research was conducted at Stanford Synchrotron Radiation Lightsource, SLAC National Laboratory, supported by the US DOE Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515, the Advanced Light Source, supported by the US DOE Office of Basic Energy Sciences under Contract No. DE-AC02-05CH11231, and at the UCLA CNSI.This is the author accepted manuscript. The final version is available from NPG at http://www.nature.com/nmat/journal/v14/n7/full/nmat4298.html

RB139, RB140, RB141 and RB142 antibodies recognize human citrullinated LL37 by ELISA

LL37 is a natural antibiotic, active against bacteria and fungi and some viruses. Here we show that three monoclonal antibodies (RB139, RB141, and RB142) are exclusively specific for citrullinated LL37, whereas RB140 recognizes both native LL37 and cit-LL37. None recognizes LL37 modified by carbamylation. These antibodies can represent previously unavailable tools to detect the presence of citrullinated LL37 in body fluids by ELISA in the course of autoimmune and infectious diseases

RB137 and RB138 antibodies recognize human cathelicidin LL37 by ELISA

LL37 is a cationic antimicrobial peptide (AMP), which can undergo post-translational modifications (PTM), such as citrullination and carbamylation. We demonstrate here that recombinant antibodies RB137 and RB138 are specific for native LL37 and do not recognize modified LL37 (citrullinated and carbamylated). They thus represent tools to assess the presence of native, unmodified LL37 in body fluids by ELISA

V2282 Sgr Revisited

The nature of V2282 Sgr is examined on the basis of several multiband observations: a 20 years long I-band light curve of V2282 Sgr obtained from archive photographic plates of the Asiago and Catania Observatories; a CCD R-band light curve obtained at Cornero Observatory; JHK photometry from 2MASS and UKDISS; Spitzer IRAC and MIPS images; optical spectra from Loiano Observatory; X-ray flux from CHANDRA. The star has a K-type spectrum with strong emission lines and is irregularly variable at all wavebands. The overall evidences suggest that V2282 Sgr is a Pre Main Sequence star with an accretion disk