Two-Dimensional Vortex Lattice Melting

We report on a Monte-Carlo study of two-dimensional Ginzburg-Landau superconductors in a magnetic field which finds clear evidence for a first-order phase transition characterized by broken translational symmetry of the superfluid density. A key aspect of our study is the introduction of a quantity proportional to the Fourier transform of the superfluid density which can be sampled efficiently in Landau gauge Monte-Carlo simulations and which satisfies a useful sum rule. We estimate the latent heat per vortex of the melting transition to be $\sim 0.38 k_B T_M$ where $T_M$ is the melting temperature.Comment: 10 pages (4 figures available on request), RevTex 3.0, IUCM93-00

Numerical Evaluation of Six-Photon Amplitudes

We apply the recently proposed amplitude reduction at the integrand level method, to the computation of the scattering process 2 photons -> 4 photons, including the case of a massive fermion loop. We also present several improvements of the method, including a general strategy to reconstruct the rational part of any one-loop amplitude and the treatment of vanishing Gram-determinants.Comment: 21 pages, 3 figures. Version accepted for publication in JHE

Improved perturbation theory in the vortex liquids state of type II superconductors

We develop an optimized perturbation theory for the Ginzburg - Landau description of thermal fluctuations effects in the vortex liquids. Unlike the high temperature expansion which is asymptotic, the optimized expansion is convergent. Radius of convergence on the lowest Landau level is $a_{T}=-3$ in 2D and $a_{T}=-5$ in 3D. It allows a systematic calculation of magnetization and specific heat contributions due to thermal fluctuations of vortices in strongly type II superconductors to a very high precision. The results are in good agreement with existing Monte Carlo simulations and experiments. Limitations of various nonperturbative and phenomenological approaches are noted. In particular we show that there is no exact intersection point of the magnetization curves both in 2D and 3D.Comment: 24 pages, 9 figure

Novae Ejecta as Colliding Shells

Following on our initial absorption-line analysis of fifteen novae spectra we present additional evidence for the existence of two distinct components of novae ejecta having different origins. As argued in Paper I one component is the rapidly expanding gas ejected from the outer layers of the white dwarf by the outburst. The second component is pre-existing outer, more slowly expanding circumbinary gas that represents ejecta from the secondary star or accretion disk. We present measurements of the emission-line widths that show them to be significantly narrower than the broad P Cygni profiles that immediately precede them. The emission profiles of novae in the nebular phase are distinctly rectangular, i.e., strongly suggestive of emission from a relatively thin, roughly spherical shell. We thus interpret novae spectral evolution in terms of the collision between the two components of ejecta, which converts the early absorption spectrum to an emission-line spectrum within weeks of the outburst. The narrow emission widths require the outer circumbinary gas to be much more massive than the white dwarf ejecta, thereby slowing the latter's expansion upon collision. The presence of a large reservoir of circumbinary gas at the time of outburst is suggestive that novae outbursts may sometime be triggered by collapse of gas onto the white dwarf, as occurs for dwarf novae, rather than steady mass transfer through the inner Lagrangian point.Comment: 12 pages, 3 figures; Revised manuscript; Accepted for publication in Astrophysics & Space Scienc

Prominent Role Of Platelets In The Formation Of Circulating Neutrophil-red Cell Heterocellular Aggregates In Sickle Cell Anemia

[No abstract available]9911e214e217Hidalgo, A., Chang, J., Jang, J.E., Peired, A.J., Chiang, E.Y., Frenette, P.S., Heterotypic interactions enabled by polarized neutrophil microdomains mediate thromboinflammatory injury (2009) Nat Med, 15 (4), pp. 384-391Turhan, A., Jenab, P., Bruhns, P., Ravetch, J.V., Coller, B.S., Frenette, P.S., Intravenous immune globulin prevents venular vaso-occlusion in sickle cell mice by inhibiting leukocyte adhesion and the interactions between sickle erythrocytes and adherent leukocytes (2004) Blood, 103 (6), pp. 2397-2400Turhan, A., Weiss, L.A., Mohandas, N., Coller, B.S., Frenette, P.S., Primary role for adherent leukocytes in sickle cell vascular occlusion: A new paradigm (2002) Proc Natl Acad Sci USA, 99 (5), pp. 3047-3051May, A.E., Langer, H., Seizer, P., Bigalke, B., Lindemann, S., Gawaz, M., Platelet-leukocyte interactions in inflammation and atherothrombosis (2007) Semin Thromb Hemost, 33 (2), pp. 123-127Gawaz, M., Fateh-Moghadam, S., Pilz, G., Gurland, H.J., Werdan, K., Platelet activation and interaction with leucocytes in patients with sepsis or multiple organ failure (1995) Eur J Clin Invest, 25 (11), pp. 843-851Polanowska-Grabowska, R., Wallace, K., Field, J.J., Chen, L., Marshall, M.A., Figler, R., P-selectin-mediated platelet-neutrophil aggregate formation activates neutrophils in mouse and human sickle cell disease (2010) Art Thromb Vascular Biol, 30 (12), pp. 2392-2399Brittain, J.E., Knoll, C.M., Ataga, K.I., Orringer, E.P., Parise, L.V., Fibronectin bridges monocytes and reticulocytes via integrin alpha4beta1 (2008) Br J Haematol, 141 (6), pp. 872-881Chaar, V., Picot, J., Renaud, O., Bartolucci, P., Nzouakou, R., Bachir, D., Aggregation of mononuclear and red blood cells through an {alpha}4{beta}1-Lu/basal cell adhesion molecule interaction in sickle cell disease (2010) Haematologica, 95 (11), pp. 1841-1848Finnegan, E.M., Turhan, A., Golan, D.E., Barabino, G.A., Adherent leukocytes capture sickle erythrocytes in an in vitro flow model of vasoocclusion (2007) Am J Hematol, 82 (4), pp. 266-275Wun, T., Paglieroni, T., Tablin, F., Welborn, J., Nelson, K., Cheung, A., Platelet activation and platelet-erythrocyte aggregates in patients with sickle cell anemia (1997) J Lab Clin Med, 129 (5), pp. 507-516Hynes, R.O., Integrins: Versatility, modulation, and signaling in cell adhesion (1992) Cell, 69 (1), pp. 11-25Novelli, E.M., Kato, G.J., Ragni, M.V., Zhang, Y., Hildesheim, M.E., Nouraie, M., Plasma thrombospondin-1 is increased during acute sickle cell vaso-occlusive events and associated with acute chest syndrome, hydroxyurea therapy, and lower hemolytic rates (2012) Am J Hematol, 87 (3), pp. 326-330Proenca-Ferreira, R., Brugnerotto, A.F., Garrido, V.T., Dominical, V.M., Vital, D.M., Ribeiro Mde, F., Endothelial activation by platelets from sickle cell anemia patients (2014) PloS one, 9 (2)Kutlar, A., Ataga, K.I., McMahon, L., Howard, J., Galacteros, F., Hagar, W., A potent oral P-selectin blocking agent improves microcirculatory blood flow and a marker of endothelial cell injury in patients with sickle cell disease (2012) Am J Hematol, 87 (5), pp. 536-539Telen, M.J., Wun, T., McCavit, T.L., De Castro, L.M., Krishnamurti, L., Lanzkron, S., GMI 1070: Reduction In Time To Resolution Of Vaso-Occlusive Crisis and Decreased Opioid Use In a Prospective, Randomized, Multi-Center Double Blind, Adaptive Phase 2 Study In Sickle Cell Disease (2013) Blood, 122 (21), p. 7. , Abstrac

Flux-lattice melting in two-dimensional disordered superconductors

The flux line lattice melting transition in two-dimensional pure and disordered superconductors is studied by a Monte Carlo simulation using the lowest Landau level approximation and quasi-periodic boundary condition on a plane. The position of the melting line was determined from the diffraction pattern of the superconducting order parameter. In the clean case we confirmed the results from earlier studies which show the existence of a quasi-long range ordered vortex lattice at low temperatures. Adding frozen disorder to the system the melting transition line is shifted to slightly lower fields. The correlations of the order parameter for translational long range order of the vortex positions seem to decay slightly faster than a power law (in agreement with the theory of Carpentier and Le Doussal) although a simple power law decay cannot be excluded. The corresponding positional glass correlation function decays as a power law establishing the existence of a quasi-long range ordered positional glass formed by the vortices. The correlation function characterizing a phase coherent vortex glass decays however exponentially ruling out the possible existence of a phase coherent vortex glass phase.Comment: 12 pages, 21 figures, final version to appear in Phys. Rev.

A Mild Case of Autosomal Recessive Osteopetrosis Masquerading as the Dominant Form Involving Homozygous Deep Intronic Variations in the CLCN7 Gene

Published online: 26 May 2022Osteopetrosis is a heterogeneous group of rare hereditary diseases characterized by increased bone mass of poor quality. Autosomal-dominant osteopetrosis type II (ADOII) is most often caused by mutation of the CLCN7 gene leading to impaired bone resorption. Autosomal recessive osteopetrosis (ARO) is a more severe form and is frequently accompanied by additional morbidities. We report an adult male presenting with classical clinical and radiological features of ADOII. Genetic analyses showed no amino-acid-converting mutation in CLCN7 but an apparent haploinsufficiency and suppression of CLCN7 mRNA levels in peripheral blood mononuclear cells. Next generation sequencing revealed low-frequency intronic homozygous variations in CLCN7, suggesting recessive inheritance. In silico analysis of an intronic duplication c.595-120_595-86dup revealed additional binding sites for Serine- and Arginine-rich Splicing Factors (SRSF), which is predicted to impair CLCN7 expression. Quantitative backscattered electron imaging and histomorphometric analyses revealed bone tissue and material abnormalities. Giant osteoclasts were present and additionally to lamellar bone, and abundant woven bone and mineralized cartilage were observed, together with increased frequency and thickness of cement lines. Bone mineralization density distribution (BMDD) analysis revealed markedly increased average mineral content of the dense bone (CaMean T-score + 10.1) and frequency of bone with highest mineral content (CaHigh T-score + 19.6), suggesting continued mineral accumulation and lack of bone remodelling. Osteocyte lacunae sections (OLS) characteristics were unremarkable except for an unusually circular shape. Together, our findings suggest that the reduced expression of CLCN7 mRNA in osteoclasts, and possibly also osteocytes, causes poorly remodelled bone with abnormal bone matrix with high mineral content. This together with the lack of adequate bone repair mechanisms makes the material brittle and prone to fracture. While the skeletal phenotype and medical history were suggestive of ADOII, genetic analysis revealed that this is a possible mild case of ARO due to deep intronic mutation.Jochen G. Hofstaetter, Gerald J. Atkins, Hajime Kato, Masakazu Kogawa, Stéphane Blouin, Barbara M. Misof, Paul Roschger, Andreas Evdokiou, Dongqing Yang, Lucian B. Solomon, David M. Findlay, Nobuaki It