456 research outputs found
Decay of correlations in the dissipative two-state system
We study the equilibrium correlation function of the polaron-dressed
tunnelling operator in the dissipative two-state system and compare the
asymptoptic dynamics with that of the position correlations. For an Ohmic
spectral density with the damping strength , the correlation functions
are obtained in analytic form for all times at any and any bias. For ,
the asymptotic dynamics is found by using a diagrammatic approach within a
Coulomb gas representation. At T=0, the tunnelling or coherence correlations
drop as , whereas the position correlations show universal decay
. The former decay law is a signature of unscreened attractive
charge-charge interactions, while the latter is due to unscreened dipole-dipole
interactions.Comment: 5 pages, 5 figures, to be published in Europhys. Let
Plastic flow of persistent currents in two dimensional strongly interacting systems
The local persistent current in two dimensional strongly interacting systems
is investigated. As the interaction strength is enhanced the current in the
sample undergoes a transition from diffusive to ordered flow. The strong
interacting flow has the characteristics of a plastic flow through dislocations
in the pinned charge density wave which develops in the system at low
densities.Comment: 12 pages, 4 figures, accepted for publication in Phys. Rev. B (RC
Staphylococcus aureus controls interleukin-5 release in upper airway inflammation
Staphylococcus aureus is a frequent colonizer of the upper airways in chronic rhinosinusitis with nasal polyps, but also resides intramucosally, it has been shown that secreted staphylococcal proteins such as enterotoxins and serine proteases induce the release of cytokines such as IL-5. We have analyzed nasal polyp tissue freshly obtained during routine surgery, which did or did not contain cultivatable S. aureus, to study spontaneous IL-5 production by nasal polyp tissue over 24 and 72 h in tissue culture In S. aureus-positive samples we interfered by killing the bacteria using antibiotics or S. aureus specific intravenous staphylococcal phages (ISP), active or heat-inactivated. Phage-neutralizing antibodies were used to demonstrate the specificity of the phage-mediated effects We monitored S. aureus colony forming units, and identified S. aureus proteins by mass spectrometry We demonstrate that cultivatable S. aureus may be found in type-2 inflamed nasal polyps, the pathogen is replicating within 24 h and secretes proteins, including enterotoxins and serine proteases The presence of S. aureus was associated with a significantly higher release of IL-5 Killing of S. aureus by antibiotics or specific ISP significantly reduced the IL-5 release. The suppressive activity of the bacteriophage on IL-5 be abolished by heat inactivation or anti-phage antibodies.
Biological significance In this study, we used high resolution mass spectrometry to identify S. aureus proteins directly in infected nasal polyp tissue and nasal polyp tissue incubated over 24 and 72 h in culture We discovered bacterial proteins including enterotoxins and serine proteases like proteins These experiments indicate a direct role of S. aureus in the regulation of IL-5 production in nasal polyps and may suggest the involvement of bacterial proteins detected in the tissues
Report and preliminary results of R/V POSEIDON cruise POS500, LISA, Ligurian Slope AUV mapping, gravity coring and seismic reflection, Catania (Italy) – Malaga (Spain), 25.05.2016 – 09.06.2016
Cruise POS500 “LISA” with R/V Poseidon studied the western Ligurian Margin off
Southern France, an area in the northeastern part of the western Mediterranean Sea
characterized by its active tectonism and frequent mass wasting. The region near the Var
estuary close to the city of Nice is particularly suited for landslide research because it
represents a natural laboratority where it is possible to study a series of trigger processes of
geological and anthropogenic origin. The aim of this MARUM expedition was to:
i. Study fresh water seepage in the marine Nice airport landslide and adjacent stable
plateau in 15-50 m water depth using water sampling, CTD and geochemistry;
ii. Recover and deploy a number of observatories that monitor, pressure, temperature, tilt
and seismicity;
iii. Run an AUV micro-bathymetric survey with MARUM AUV SEAL5000 to
complement existing multibeam maps; and
iv. Acquire additional high-resolution seismic reflection profiles to unravel the complex
architecture of the Nice slope and Var delta.
In a period of approximately two weeks, we acquired valuable geophysical information that
helps to understand the evolution of this portion of the Ligurian Margin and further to
support an active Amphibious Drilling proposal submitted to ICDP and IODP. We could
also show that heavy spring rainfall plus melt water from the French Maritime Alps supplied
sufficient hydraulic forcing to push Var aquifer groundwaters to seep into the marine
deposits and water column. Freshening was strongest in the 1979 Nice landslide scar, but
was also found at the outer edge of the shelf. Recovery and redeployment of various
observatory prototypes worked well, both for the MARUM MeBo seafloor drillstring tolos
and independent piezometers.
Observatory data have yet to be evaluated. In addition, geochemical analyses of bottom
waters and pore waters was deferred to shore-based laboratorios except for salinity estimates
using a refractometer. Seismic processing was started onboard, but is largely taking place
post-cruise at University Bremen
Comparison of genotyping using pooled DNA samples (allelotyping) and individual genotyping using the affymetrix genome-wide human SNP array 6.0
Background: Genome-wide association studies (GWAS) using array-based genotyping technology are widely used to identify genetic loci associated with complex diseases or other phenotypes. The costs of GWAS projects based on individual genotyping are still comparatively high and increase with the size of study populations. Genotyping using pooled DNA samples, as also being referred as to allelotyping approach, offers an alternative at affordable costs. In the
Sheared Flow As A Stabilizing Mechanism In Astrophysical Jets
It has been hypothesized that the sustained narrowness observed in the
asymptotic cylindrical region of bipolar outflows from Young Stellar Objects
(YSO) indicates that these jets are magnetically collimated. The j cross B
force observed in z-pinch plasmas is a possible explanation for these
observations. However, z-pinch plasmas are subject to current driven
instabilities (CDI). The interest in using z-pinches for controlled nuclear
fusion has lead to an extensive theory of the stability of magnetically
confined plasmas. Analytical, numerical, and experimental evidence from this
field suggest that sheared flow in magnetized plasmas can reduce the growth
rates of the sausage and kink instabilities. Here we propose the hypothesis
that sheared helical flow can exert a similar stabilizing influence on CDI in
YSO jets.Comment: 13 pages, 2 figure
Proteomic and transcriptomic changes in hibernating grizzly bears reveal metabolic and signaling pathways that protect against muscle atrophy
Muscle atrophy is a physiological response to disuse and malnutrition, but hibernating bears are largely resistant to this phenomenon. Unlike other mammals, they efficiently reabsorb amino acids from urine, periodically activate muscle contraction, and their adipocytes differentially responds to insulin. The contribution of myocytes to the reduced atrophy remains largely unknown. Here we show how metabolism and atrophy signaling are regulated in skeletal muscle of hibernating grizzly bear. Metabolic modeling of proteomic changes suggests an autonomous increase of non-essential amino acids (NEAA) in muscle and treatment of differentiated myoblasts with NEAA is sufficient to induce hypertrophy. Our comparison of gene expression in hibernation versus muscle atrophy identified several genes differentially regulated during hibernation, including Pdk4 and Serpinf1. Their trophic effects extend to myoblasts from non-hibernating species (including C. elegans), as documented by a knockdown approach. Together, these changes reflect evolutionary favored adaptations that, once translated to the clinics, could help improve atrophy treatment
Genome-Wide Association Study with Targeted and Non-targeted NMR Metabolomics Identifies 15 Novel Loci of Urinary Human Metabolic Individuality
Genome-wide association studies with metabolic traits (mGWAS) uncovered many genetic variants that influence human metabolism. These genetically influenced metabotypes (GIMs) contribute to our metabolic individuality, our capacity to respond to environmental challenges, and our susceptibility to specific diseases. While metabolic homeostasis in blood is a well investigated topic in large mGWAS with over 150 known loci, metabolic detoxification through urinary excretion has only been addressed by few small mGWAS with only 11 associated loci so far. Here we report the largest mGWAS to date, combining targeted and non-targeted 1H NMR analysis of urine samples from 3,861 participants of the SHIP-0 cohort and 1,691 subjects of the KORA F4 cohort. We identified and replicated 22 loci with significant associations with urinary traits, 15 of which are new (HIBCH, CPS1, AGXT, XYLB, TKT, ETNPPL, SLC6A19, DMGDH, SLC36A2, GLDC, SLC6A13, ACSM3, SLC5A11, PNMT, SLC13A3). Two-thirds of the urinary loci also have a metabolite association in blood. For all but one of the 6 loci where significant associations target the same metabolite in blood and urine, the genetic effects have the same direction in both fluids. In contrast, for the SLC5A11 locus, we found increased levels of myo-inositol in urine whereas mGWAS in blood reported decreased levels for the same genetic variant. This might indicate less effective re-absorption of myo-inositol in the kidneys of carriers. In summary, our study more than doubles the number of known loci that influence urinary phenotypes. It thus allows novel insights into the relationship between blood homeostasis and its regulation through excretion. The newly discovered loci also include variants previously linked to chronic kidney disease (CPS1, SLC6A13), pulmonary hypertension (CPS1), and ischemic stroke (XYLB). By establishing connections from gene to disease via metabolic traits our results provide novel hypotheses about molecular mechanisms involved in the etiology of diseases
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