52 research outputs found
Extended Analysis of Gravitomagnetic Fields in Rotating Superconductors and Superfluids
Applying the Ginzburg-Landau theory including frame dragging effects to the
case of a rotating superconductor, we were able to express the absolute value
of the gravitomagnetic field involved to explain the Cooper pair mass anomaly
previously reported by Tate. Although our analysis predicts large
gravitomagnetic fields originated by superconductive gyroscopes, those should
not affect the measurement of the Earth gravitomagnetic field by the Gravity
Probe-B satellite. However, the hypothesis might be well suited to explain a
mechanical momentum exchange phenomena reported for superfluid helium. As a
possible explanation for those abnormally large gravitomagnetic fields in
quantum materials, the reduced speed of light (and gravity) that was found in
the case of Bose-Einstein condensates is analysed
MARS therapy, the bridging to liver retransplantation-Three cases from the Hungarian liver transplant program
Besides orthotopic liver transplantation (OLT) there is no long-term and effective replacement therapy for severe liver failure. Artificial extracorporeal liver supply devices are able to reduce blood toxin levels, but do not replace any synthetic function of the liver. Molecular adsorbent recirculating system (MARS) is one of the methods that can be used to treat fulminant acute liver failure (ALF) or acute on chronic liver failure (AoCLF). The primary non-function (PNF) of the newly transplanted liver manifests in the clinical settings exactly like acute liver failure. MARS treatment can reduce the severity of complications by eliminating blood toxins, so that it can help hepatic encephalopathy (HE), hepatorenal syndrome (HRS), and the high rate mortality of cerebral herniation. This might serve as a bridging therapy before orthotopic liver retransplantation (reOLT). Three patients after a first liver transplantation became candidate for urgent MARS treatment as a bridging solution prior to reOLT in our center. Authors report these three cases, focusing on indications, MARS sessions, clinical courses, and final outcomes. © 2013 Akadémiai Kiadó, Budapest
Spanning forests and the q-state Potts model in the limit q \to 0
We study the q-state Potts model with nearest-neighbor coupling v=e^{\beta
J}-1 in the limit q,v \to 0 with the ratio w = v/q held fixed. Combinatorially,
this limit gives rise to the generating polynomial of spanning forests;
physically, it provides information about the Potts-model phase diagram in the
neighborhood of (q,v) = (0,0). We have studied this model on the square and
triangular lattices, using a transfer-matrix approach at both real and complex
values of w. For both lattices, we have computed the symbolic transfer matrices
for cylindrical strips of widths 2 \le L \le 10, as well as the limiting curves
of partition-function zeros in the complex w-plane. For real w, we find two
distinct phases separated by a transition point w=w_0, where w_0 = -1/4 (resp.
w_0 = -0.1753 \pm 0.0002) for the square (resp. triangular) lattice. For w >
w_0 we find a non-critical disordered phase, while for w < w_0 our results are
compatible with a massless Berker-Kadanoff phase with conformal charge c = -2
and leading thermal scaling dimension x_{T,1} = 2 (marginal operator). At w =
w_0 we find a "first-order critical point": the first derivative of the free
energy is discontinuous at w_0, while the correlation length diverges as w
\downarrow w_0 (and is infinite at w = w_0). The critical behavior at w = w_0
seems to be the same for both lattices and it differs from that of the
Berker-Kadanoff phase: our results suggest that the conformal charge is c = -1,
the leading thermal scaling dimension is x_{T,1} = 0, and the critical
exponents are \nu = 1/d = 1/2 and \alpha = 1.Comment: 131 pages (LaTeX2e). Includes tex file, three sty files, and 65
Postscript figures. Also included are Mathematica files forests_sq_2-9P.m and
forests_tri_2-9P.m. Final journal versio
Monopolium: the key to monopoles
Dirac showed that the existence of one magnetic pole in the universe could offer an explanation for the discrete nature of the electric charge. Magnetic poles appear naturally in most Grand Unified Theories. Their discovery would be of greatest importance for particle physics and cosmology. The intense experimental search carried thus far has not met with success. Moreover, if the monopoles are very massive their production is outside the range of present day facilities. A way out of this impasse would be if the monopoles bind to form monopolium, a monopole- antimonopole bound state, which is so strongly bound, that it has a relatively small mass. Under these circumstances it could be produced with present day facilities and the existence of monopoles could be indirectly proven. We study the feasibility of detecting monopolium in present and future accelerators
Large-scale sequencing identifies multiple genes and rare variants associated with Crohn's disease susceptibility
Genome-wide association studies (GWASs) have identified hundreds of loci associated with Crohn's disease (CD). However, as with all complex diseases, robust identification of the genes dysregulated by noncoding variants typically driving GWAS discoveries has been challenging. Here, to complement GWASs and better define actionable biological targets, we analyzed sequence data from more than 30,000 patients with CD and 80,000 population controls. We directly implicate ten genes in general onset CD for the first time to our knowledge via association to coding variation, four of which lie within established CD GWAS loci. In nine instances, a single coding variant is significantly associated, and in the tenth, ATG4C, we see additionally a significantly increased burden of very rare coding variants in CD cases. In addition to reiterating the central role of innate and adaptive immune cells as well as autophagy in CD pathogenesis, these newly associated genes highlight the emerging role of mesenchymal cells in the development and maintenance of intestinal inflammation.Large-scale sequence-based analyses identify novel risk variants and susceptibility genes for Crohn's disease, and implicate mesenchymal cell-mediated intestinal homeostasis in disease etiology.Cellular mechanisms in basic and clinical gastroenterology and hepatolog
Late Quaternary tephrostratigraphy, Ahklun Mountains, SW Alaska
Radiocarbon-dated sediment cores from six lakes in the Ahklun Mountains, south-western Alaska, were used to interpolate the ages of late Quaternary tephra beds ranging in age from 25.4 to 0.4ka. The lakes are located downwind of the Aleutian Arc and Alaska Peninsula volcanoes in the northern Bristol Bay area between 159° and 161°W at around 60°N. Sedimentation-rate age models for each lake were based on a published spline-fit procedure that uses Monte Carlo simulation to determine age model uncertainty. In all, 62 C ages were used to construct the six age models, including 23 ages presented here for the first time. The age model from Lone Spruce Pond is based on 18 ages, and is currently the best-resolved Holocene age model available from the region, with an average 2s age uncertainty of about±109 years over the past 14.5ka. The sedimentary sequence from Lone Spruce Pond contains seven tephra beds, more than previously found in any other lake in the area. Of the 26 radiocarbon-dated tephra beds at the six lakes and from a soil pit, seven are correlated between two or more sites based on their ages. The major-element geochemistry of glass shards from most of these tephra beds supports the age-based correlations. The remaining tephra beds appear to be present at only one site based on their unique geochemistry or age. The 5.8ka tephra is similar to the widespread Aniakchak tephra [3.7±0.2 (1s) ka], but can be distinguished conclusively based on its trace-element geochemistry. The 3.1 and 0.4ka tephras have glass major- and trace-element geochemical compositions indistinguishable from prominent Aniakchak tephra, and might represent redeposited beds. Only two tephra beds are found in all lakes: the Aniakchak tephra (3.7±0.2ka) and Tephra B (6.1±0.3ka). The tephra beds can be used as chronostratigraphic markers for other sedimentary sequences in the region, including cores from Cascade and Sunday lakes, which were previously undated and were analyzed in this study to correlate with the new regional tephrostratigraphy
Saturation of low-energy anti-proton annihilation on nuclei
Recent measurements of very low-energy ( MeV/c)
annihilation on light nuclei reveal apparent suppression of annihilation upon
increasing the atomic charge and mass number . Using -nucleus
optical potentials , fitted to -atom energy-shifts and
-widths, we resolve this suppression as due to the strong effective repulsion
produced by the very absorptive . The low-energy -nucleus wavefunction is kept substantially outside the nuclear surface and
the resulting reaction cross section saturates as function of the strength of
Im . This feature, for , parallels the recent prediction,
for , that the level widths of atoms saturate and, hence, that
deeply bound atomic states are relatively narrow. Antiproton
annihilation cross sections are calculated at MeV/c across the
periodic table, and their dependence on and is classified and discussed
with respect to the Coulomb focussing effect at very low energies.Comment: 10 pages, 3 figures, slightly revised version, PLB in pres
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