428 research outputs found
Extended chiral algebras and the emergence of SU(2) quantum numbers in the Coulomb gas
We study a set of chiral symmetries contained in degenerate operators beyond
the `minimal' sector of the c(p,q) models. For the operators
h_{(2j+2)q-1,1}=h_{1,(2j+2)p-1} at conformal weight [ (j+1)p-1 ][ (j+1)q -1 ],
for every 2j \in N, we find 2j+1 chiral operators which have quantum numbers of
a spin j representation of SU(2). We give a free-field construction of these
operators which makes this structure explicit and allows their OPEs to be
calculated directly without any use of screening charges. The first non-trivial
chiral field in this series, at j=1/2, is a fermionic or para-fermionic
doublet. The three chiral bosonic fields, at j=1, generate a closed W-algebra
and we calculate the vacuum character of these triplet models.Comment: 23 pages Late
A Novel Sparse Graphical Approach for Multimodal Brain Connectivity Inference
International audienceDespite the clear potential benefits of combining fMRI and diffusion MRI in learning the neural pathways that underlie brain functions, little methodological progress has been made in this direction. In this paper, we propose a novel multimodal integration approach based on sparse Gaussian graphical model for estimating brain connectivity. Casting functional connectivity estimation as a sparse inverse covariance learning problem, we adapt the level of sparse penalization on each connection based on its anatomical capacity for functional interactions. Functional connections with little anatomical support are thus more heavily penalized. For validation, we showed on real data collected from a cohort of 60 subjects that additionally modeling anatomical capacity significantly increases subject consistency in the detected connection patterns. Moreover, we demonstrated that incorporating a connectivity prior learned with our multimodal connectivity estimation approach improves activation detection
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
Maintenance and expansion of genetic and trait variation following domestication in a clonal crop
Clonal propagation enables favourable crop genotypes to be rapidly selected and multiplied. However, the absence of sexual propagation can lead to low genetic diversity and accumulation of deleterious mutations, which may eventually render crops less resilient to pathogens or environmental change. To better understand this trade-off, we characterize the domestication and contemporary genetic diversity of Enset (Ensete ventricosum), an indigenous African relative of bananas (Musa) and a principal starch staple for 20 million Ethiopians. Wild enset reproduction occurs strictly by sexual outcrossing, but for cultivation, it is propagated clonally and associated with diversification and specialization into hundreds of named landraces. We applied tGBS sequencing to generate genome-wide genotypes for 192 accessions from across enset's cultivated distribution, and surveyed 1340 farmers on enset agronomic traits. Overall, reduced heterozygosity in the domesticated lineage was consistent with a domestication bottleneck that retained 37% of wild diversity. However, an excess of putatively deleterious missense mutations at low frequency present as heterozygotes suggested an accumulation of mutational load in clonal domesticated lineages. Our evidence indicates that the major domesticated lineages initially arose through historic sexual recombination associated with a domestication bottleneck, followed by the amplification of favourable genotypes through an extended period of clonal propagation. Among domesticated lineages, we found a significant phylogenetic signal for multiple farmer-identified food, nutrition and disease resistance traits and little evidence of contemporary recombination. The development of future-climate adapted genotypes may require crop breeding, but outcrossing risks exposing deleterious alleles as homozygotes. This trade-off may partly explain the ubiquity and persistence of clonal propagation over recent centuries of comparative climate stability
Chandra HETG X-ray spectra and variability of π Aqr, a γ Cas-type Be star
High-resolution X-ray spectra of π Aqr, a γ Cas-type star, obtained with the Chandra/HETG spectrometer, revealed emission lines of H-like ions of Mg, Si, S, and Fe; a strong, hard continuum; and a lack of He-like ions, indicating the presence of very hot thermal plasma. The X-ray light curve showed significant fluctuations, with coherent variability at a period of about 3400 s in one observation. The hardness ratio was relatively constant except for one observation in which the spectrum was much harder and more absorbed. We interpret the X-ray emission as arising from accretion onto the secondary, which is likely a magnetic white dwarf, an intermediate polar system
Characterisation of the muon beams for the Muon Ionisation Cooling Experiment
A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.2–2.3 π mm-rad horizontally and 0.6–1.0 π mm-rad vertically, a horizontal dispersion of 90–190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE
A search for the cause of cyclical wind variability in O stars. Simultaneous UV and optical observations including magnetic field measurements of the O7.5III star xi Persei
Measurement of B(D_s+ -> mu+ nu_mu)/B(D_s+ -> phi mu+ nu_mu) and Determination of the Decay Constant f_{D_s}
We have observed purely-leptonic decays of
from a sample of muonic one prong decay events
detected in the emulsion target of Fermilab experiment E653. Using the yield measured previously in this experiment, we obtain
. In addition, we extract the decay constant .Comment: 15 pages including one figur
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