Radio variability of 1st 3-months Fermi blazars at 5 GHz: affected by interstellar scintillation?

Blazars from the first-three-months Fermi-AGN list were observed with the Urumqi 25m radio telescope at 5GHz in IDV (Intra-Day Variability) mode and inter-month observation mode. A significant correlation between the flux density at 5GHz and the gamma-ray intensity for the Fermi-LAT detected blazars is seen. There is a higher IDV detection rate in Fermi detected blazars than those reported for other samples. Stronger variability appears at lower Galactic latitudes; IDV appears to be stronger in weaker sources, indicating that the variability is affected by interstellar scintillation.Comment: 4 pages, 4 figures, in proceedings of 'Multiwavelength Variability of Blazars' in Guangzhou Uni. of China, 22-24, Sep. 2010, to appear in JA

Conduction of Ultracold Fermions Through a Mesoscopic Channel

In a mesoscopic conductor electric resistance is detected even if the device is defect-free. We engineer and study a cold-atom analog of a mesoscopic conductor. It consists of a narrow channel connecting two macroscopic reservoirs of fermions that can be switched from ballistic to diffusive. We induce a current through the channel and find ohmic conduction, even for a ballistic channel. An analysis of in-situ density distributions shows that in the ballistic case the chemical potential drop occurs at the entrance and exit of the channel, revealing the presence of contact resistance. In contrast, a diffusive channel with disorder displays a chemical potential drop spread over the whole channel. Our approach opens the way towards quantum simulation of mesoscopic devices with quantum gases

Bioassay-guided isolation and identification of antimicrobial compounds from thyme essential oil by means of overpressured layer chromatography, bioautography and GC-MS

A simple method is described for efficient isolation of compounds having an antibacterial effect. Two thyme (Thymus vulgaris) essential oils, obtained from the market, were chosen as prospective materials likely to feature several bioactive components when examined by thin layer chromatography coupled with direct bioautography as a screening method. The newly developed infusion overpressured layer chromatographic separation method coupled with direct bioautography assured that only the active components were isolated by means of overrun overpressured layer chromatography with online detection and fractionation. Each of the 5 collected fractions represented one of the five antimicrobial essential oil components designated at the screening. The purity and the activity of the fractions were confirmed with chromatography coupled various detection methods (UV, vanillin-sulphuric acid reagent, direct bioautography). The antibacterial components were identified with GC-MS as thymol, carvacrol, linalool, diethylphthalate, and alpha-terpineol. The oil component diethyl-phthalate is an artificial compound, used as plasticizer or detergent bases in the industry. Our results support that exploiting its flexibility and the possible hyphenations, overpressured layer chromatography is especially attractive for isolation of antimicrobial components from various matrixes

Creation of Laryngeal Grafts from Primary Human Cells and Decellularized Laryngeal Scaffolds

Current reconstruction methods of the laryngotracheal segment fail to replace the complex functions of the human larynx. Bioengineering approaches to reconstruction have been limited by the complex tissue compartmentation of the larynx. We attempted to overcome this limitation by bio-engineering laryngeal grafts from decellularized canine laryngeal scaffolds recellularized with human primary cells under one uniform culture medium condition. First, we generated laryngeal scaffolds with preserved glycosaminoglycan content and biomechanical properties by detergent perfusion-decellularization over nine days. We proofed biocompatibility by absence of a CD3 lymphocyte response to subcutaneously implanted scaffolds in immune-competent rats. We then developed a uniform culture medium that strengthened the endothelial barrier over 5 days after an initial growth phase. Simultaneously, this culture medium supported airway epithelial cell and skeletal myoblast growth while maintaining their full differentiation and maturation potential. We then applied the uniform culture medium composition to whole laryngeal scaffolds seeded with endothelial cells from both carotid arteries and external jugular veins and generated re-endothelialized arterial and venous vascular beds. Under the same culture medium condition, we bio-engineered epithelial monolayers onto laryngeal mucosa and repopulated intrinsic laryngeal muscle. We were then able to demonstrate early muscle formation in heterotopic transplantations in immuno-deficient mice. The model supported the formation of three humanized laryngeal tissue compartments under one uniform culture condition, possibly a key factor in developing, complex, multicellular, ready-to-transplant tissue grafts

Cosmogenic neutron production at the Sudbury Neutrino Observatory

Neutrons produced in nuclear interactions initiated by cosmic-ray muons present an irreducible background to many rare-event searches, even in detectors located deep underground. Models for the production of these neutrons have been tested against previous experimental data, but the extrapolation to deeper sites is not well understood. Here we report results from an analysis of cosmogenically produced neutrons at the Sudbury Neutrino Observatory. A specific set of observables are presented, which can be used to benchmark the validity of geant4 physics models. In addition, the cosmogenic neutron yield, in units of 10-4 cm2/(g·μ), is measured to be 7.28±0.09(stat)-1.12+1.59(syst) in pure heavy water and 7.30±0.07(stat)-1.02+1.40(syst) in NaCl-loaded heavy water. These results provide unique insights into this potential background source for experiments at SNOLAB

Characterization of Novel Cutaneous Human Papillomavirus Genotypes HPV-150 and HPV-151

DNA from two novel HPV genotypes, HPV-150 and HPV-151, isolated from hair follicles of immuno-competent individuals, was fully cloned, sequenced and characterized. The complete genomes of HPV-150 and HPV-151 are 7,436-bp and 7,386-bp in length, respectively. Both contain genes for at least six proteins, namely E6, E7, E1, E2, L2, L1, as well as a non-coding upstream regulatory region located between the L1 and E6 genes: spanning 416-bp in HPV-150 (genomic positions 7,371 to 350) and 322-bp in HPV-151 (genomic positions 7,213 to 148). HPV-150 and HPV-151 are phylogenetically placed within the Betapapillomavirus genus and are most closely related to HPV-96 and HPV-22, respectively. As in other members of this genus, the intergenic E2-L2 region is very short and does not encode for an E5 gene. Both genotypes contain typical zinc binding domains in their E6 and E7 proteins, but HPV-151 lacks the regular pRb-binding core sequence within its E7 protein. In order to assess the tissue predilection and clinical significance of the novel genotypes, quantitative type-specific real-time PCR assays were developed. The 95% detection limits of the HPV-150 and HPV-151 assays were 7.3 copies/reaction (range 5.6 to 11.4) and 3.4 copies/reaction (range 2.5 to 6.0), respectively. Testing of a representative collection of HPV-associated mucosal and cutaneous benign and malignant neoplasms and hair follicles (total of 540 samples) revealed that HPV-150 and HPV-151 are relatively rare genotypes with a cutaneous tropism. Both genotypes were found in sporadic cases of common warts and SCC and BCC of the skin as single or multiple infections usually with low viral loads. HPV-150 can establish persistent infection of hair follicles in immuno-competent individuals. A partial L1 sequence of a putative novel HPV genotype, related to HPV-150, was identified in a squamous cell carcinoma of the skin obtained from a 64-year old immuno-compromised male patient

Physics, Astrophysics and Cosmology with Gravitational Waves

Gravitational wave detectors are already operating at interesting sensitivity levels, and they have an upgrade path that should result in secure detections by 2014. We review the physics of gravitational waves, how they interact with detectors (bars and interferometers), and how these detectors operate. We study the most likely sources of gravitational waves and review the data analysis methods that are used to extract their signals from detector noise. Then we consider the consequences of gravitational wave detections and observations for physics, astrophysics, and cosmology.Comment: 137 pages, 16 figures, Published version <http://www.livingreviews.org/lrr-2009-2

Comparative genomics of Escherichia coli isolated from patients with inflammatory bowel disease

<p>Abstract</p> <p>Background</p> <p>Inflammatory bowel disease (IBD) is used to describe a state of idiopathic, chronic inflammation of the gastrointestinal tract. The two main phenotypes of IBD are Crohn's disease (CD) and ulcerative colitis (UC). The major cause of IBD-associated mortality is colorectal cancer. Although both host-genetic and exogenous factors have been found to be involved, the aetiology of IBD is still not well understood. In this study we characterized thirteen <it>Escherichia coli </it>strains from patients with IBD by comparative genomic hybridization employing a microarray based on 31 sequenced <it>E. coli </it>genomes from a wide range of commensal and pathogenic isolates.</p> <p>Results</p> <p>The IBD isolates, obtained from patients with UC and CD, displayed remarkably heterogeneous genomic profiles with little or no evidence of group-specific determinants. No IBD-specific genes were evident when compared with the prototypic CD isolate, LF82, suggesting that the IBD-inducing effect of the strains is multifactorial. Several of the IBD isolates carried a number of extraintestinal pathogenic <it>E. coli </it>(ExPEC)-related virulence determinants such as the <it>pap</it>, <it>sfa</it>, <it>cdt </it>and <it>hly </it>genes. The isolates were also found to carry genes of ExPEC-associated genomic islands.</p> <p>Conclusions</p> <p>Combined, these data suggest that <it>E. coli </it>isolates obtained from UC and CD patients represents a heterogeneous population of strains, with genomic profiles that are indistinguishable to those of ExPEC isolates. Our findings indicate that IBD-induction from <it>E. coli </it>strains is multifactorial and that a range of gene products may be involved in triggering the disease.</p

Gravitational Waves from Gravitational Collapse

Gravitational wave emission from the gravitational collapse of massive stars has been studied for more than three decades. Current state of the art numerical investigations of collapse include those that use progenitors with realistic angular momentum profiles, properly treat microphysics issues, account for general relativity, and examine non--axisymmetric effects in three dimensions. Such simulations predict that gravitational waves from various phenomena associated with gravitational collapse could be detectable with advanced ground--based and future space--based interferometric observatories.Comment: 68 pages including 13 figures; revised version accepted for publication in Living Reviews in Relativity (http://www.livingreviews.org