Stationary State Solutions of a Bond Diluted Kinetic Ising Model: An Effective-Field Theory Analysis

We have examined the stationary state solutions of a bond diluted kinetic Ising model under a time dependent oscillating magnetic field within the effective-field theory (EFT) for a honeycomb lattice $(q=3)$. Time evolution of the system has been modeled with a formalism of master equation. The effects of the bond dilution, as well as the frequency $(\omega)$ and amplitude $(h/J)$ of the external field on the dynamic phase diagrams have been discussed in detail. We have found that the system exhibits the first order phase transition with a dynamic tricritical point (DTCP) at low temperature and high amplitude regions, in contrast to the previously published results for the pure case \cite{Ling}. Bond dilution process on the kinetic Ising model gives rise to a number of interesting and unusual phenomena such as reentrant phenomena and has a tendency to destruct the first-order transitions and the DTCP. Moreover, we have investigated the variation of the bond percolation threshold as functions of the amplitude and frequency of the oscillating field.Comment: 8 pages, 4 figure

Vortex Lattice Melting into Disentangled Liquid Followed by the 3D-2D Decoupling Transition in YBa_2Cu_4O_8 Single Crystals

A sharp resistance drop associated with vortex lattice melting was observed in high quality YBa_2Cu_4O_8 single crystals. The melting line is well described well by the anisotropic GL theory. Two thermally activated flux flow regions, which were separated by a crossover line B_cr=1406.5(1-T/T_c)/T (T_c=79.0 K, B_cr in T), were observed in the vortex liquid phase. Activation energy for each region was obtained and the corresponding dissipation mechanism was discussed. Our results suggest that the vortex lattice in YBa_2Cu_4O_8 single crystal melts into disentangled liquid, which then undergoes a 3D-2D decoupling transition.Comment: 5 pages, 4 eps figures, RevTex (Latex2.09

Leaderless deterministic chemical reaction networks

This paper answers an open question of Chen, Doty, and Soloveichik [1], who showed that a function f:N^k --> N^l is deterministically computable by a stochastic chemical reaction network (CRN) if and only if the graph of f is a semilinear subset of N^{k+l}. That construction crucially used "leaders": the ability to start in an initial configuration with constant but non-zero counts of species other than the k species X_1,...,X_k representing the input to the function f. The authors asked whether deterministic CRNs without a leader retain the same power. We answer this question affirmatively, showing that every semilinear function is deterministically computable by a CRN whose initial configuration contains only the input species X_1,...,X_k, and zero counts of every other species. We show that this CRN completes in expected time O(n), where n is the total number of input molecules. This time bound is slower than the O(log^5 n) achieved in [1], but faster than the O(n log n) achieved by the direct construction of [1] (Theorem 4.1 in the latest online version of [1]), since the fast construction of that paper (Theorem 4.4) relied heavily on the use of a fast, error-prone CRN that computes arbitrary computable functions, and which crucially uses a leader.Comment: arXiv admin note: substantial text overlap with arXiv:1204.417

Anomalous behavior in an effective model of graphene with Coulomb interactions

We analyze by exact Renormalization Group (RG) methods the infrared properties of an effective model of graphene, in which two-dimensional massless Dirac fermions propagating with a velocity smaller than the speed of light interact with a three-dimensional quantum electromagnetic field. The fermionic correlation functions are written as series in the running coupling constants, with finite coefficients that admit explicit bounds at all orders. The implementation of Ward Identities in the RG scheme implies that the effective charges tend to a line of fixed points. At small momenta, the quasi-particle weight tends to zero and the effective Fermi velocity tends to a finite value. These limits are approached with a power law behavior characterized by non-universal critical exponents.Comment: 42 pages, 7 figures; minor corrections, one appendix added (Appendix A). To appear in Ann. Henri Poincar

Classification of a supersolid: Trial wavefunctions, Symmetry breakings and Excitation spectra

A state of matter is characterized by its symmetry breaking and elementary excitations. A supersolid is a state which breaks both translational symmetry and internal $U(1)$ symmetry. Here, we review some past and recent works in phenomenological Ginsburg-Landau theories, ground state trial wavefunctions and microscopic numerical calculations. We also write down a new effective supersolid Hamiltonian on a lattice. The eigenstates of the Hamiltonian contains both the ground state wavefunction and all the excited states (supersolidon) wavefunctions. We contrast various kinds of supersolids in both continuous systems and on lattices, both condensed matter and cold atom systems. We provide additional new insights in studying their order parameters, symmetry breaking patterns, the excitation spectra and detection methods.Comment: REVTEX4, 19 pages, 3 figure

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

Integrated analyses of single-cell atlases reveal age, gender, and smoking status associations with cell type-specific expression of mediators of SARS-CoV-2 viral entry and highlights inflammatory programs in putative target cells

The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, creates an urgent need for identifying molecular mechanisms that mediate viral entry, propagation, and tissue pathology. Cell membrane bound angiotensin-converting enzyme 2 (ACE2) and associated proteases, transmembrane protease serine 2 (TMPRSS2) and Cathepsin L (CTSL), were previously identified as mediators of SARS-CoV2 cellular entry. Here, we assess the cell type-specific RNA expression of ACE2, TMPRSS2, and CTSL through an integrated analysis of 107 single-cell and single-nucleus RNA-Seq studies, including 22 lung and airways datasets (16 unpublished), and 85 datasets from other diverse organs. Joint expression of ACE2 and the accessory proteases identifies specific subsets of respiratory epithelial cells as putative targets of viral infection in the nasal passages, airways, and alveoli. Cells that co-express ACE2 and proteases are also identified in cells from other organs, some of which have been associated with COVID-19 transmission or pathology, including gut enterocytes, corneal epithelial cells, cardiomyocytes, heart pericytes, olfactory sustentacular cells, and renal epithelial cells. Performing the first meta-analyses of scRNA-seq studies, we analyzed 1,176,683 cells from 282 nasal, airway, and lung parenchyma samples from 164 donors spanning fetal, childhood, adult, and elderly age groups, associate increased levels of ACE2, TMPRSS2, and CTSL in specific cell types with increasing age, male gender, and smoking, all of which are epidemiologically linked to COVID-19 susceptibility and outcomes. Notably, there was a particularly low expression of ACE2 in the few young pediatric samples in the analysis. Further analysis reveals a gene expression program shared by ACE2(+)TMPRSS2(+) cells in nasal, lung and gut tissues, including genes that may mediate viral entry, subtend key immune functions, and mediate epithelial-macrophage cross-talk. Amongst these are IL6, its receptor and co-receptor, IL1R, TNF response pathways, and complement genes. Cell type specificity in the lung and airways and smoking effects were conserved in mice. Our analyses suggest that differences in the cell type-specific expression of mediators of SARS-CoV-2 viral entry may be responsible for aspects of COVID-19 epidemiology and clinical course, and point to putative molecular pathways involved in disease susceptibility and pathogenesis

Plasma gut hormone levels in 37 patients with pheochromocytomas

Pheochromocytomas are usually recognized by the effects of overproduction of catecholamines, but there are clinical features that cannot be ascribed to catecholamine excess that may be due to vasoactive peptides. We, therefore, measured blood levels of vasoactive intestinal peptides (VIP), substance P, somatostatin (SS), and motilin in 50 instances in 37 patients with pheochromocytomas-21 malignant, 10 benign intra-adrenal, and 6 ectopic (5 paracardial and 1 perirenal). Hormone levels were considered raised if the level was more than 3 S.D. above the mean value found in 52 healthy subjects. Of the 37 patients, 20 (54%) had an abnormality in 1 or more gut hormone levels. The most common abnormality was a raised SS in 9/37 (24%). In addition to these, however, 3 (8%) others had raised VIP, 5 (13.5%) raised motilin, and 3 (8%) raised substance P. Patients with benign adrenal adenomas had raised levels of SS and substance P. Ectopic pheochromocytomas produced only SS in addition to catecholamines, but malignant pheochromocytomas could secrete all 4 peptides, and more than 1 in the same patient. We conclude that pheochromocytomas may secrete multiple vasoactive peptides, and they are more likely to do so if malignant. Somatostatin is the most commonly secreted peptide and is found with benign adrenal and ectopic (paracardiac) tumors. If the level of more than 1 peptide is elevated, the likelihood of malignancy is significantly increased . Les phéochromocytomes sont généralement déceléspar les effets dûs à la surproduction de catécholamines, mais certains troubles ne peuvent être attribués à ce phénomène et relèvent peut être de l'action de peptides vasoactifs. Les auteurs se sont donc attachés à doser dans le sang le VIP, la substance P, la somatostatine (SS), et la motiline. Ces dosages furent pratiqués 50 fois chez 37 malades porteurs de phéochromocytomes: 21 malins, 10 bénins et 6 ectopiques (5 paracardiaque et 1 péri-rénal). Les taux des hormones furent considérés comme élevés lorsque leur niveau fut supérieur à plus de 3 fois le taux de 52 sujets sains. Sur les 37 malades 20 (54%) présentaient un excès d'une ou de plusieurs hormones digestives. L'anomalie constatée la plus fréquente fut l'élévation de la SS (9 fois sur 37 soit 24%). Ajoutée à ce fait fut l'élévation de la VIP chez 3 sujets (8%), de la motiline chez 5 (13.5%) et de la substance P chez 3 (8%). Les phéochromocytomes bénins surrénaliens présentaient à la fois une élévation du taux de la SS et de la substance P. Les phéochromocytomes ectopiques en revanche présentaient seulement une élévation de la SS. Les phéochromocytomes malins pouvaient sécréter les 4 peptides ou plus d'un chez le même malade. En conclusion les phéochromocytomes peuvent secréter de multiples peptides vasoactifs et plus particulièrement lorsqu'ils sont malins. La SS est la substance qui est la plus souvent secrétée et elle est trouvée dans les tumeurs bénignes surrénaliennes ou ectopiques. Si plus d'une de ces substances est produite en excès les risques de malignité de la tumeur sont significativement plus importants. Los feocromocitomas generalmente son diagnosticados por los efectos del exceso de producción de catecolaminas pero hay características clínicas que no pueden ser atribuidas al exceso de catecolaminas y que pueden ser más bien manifestación de péptidos vasoactivos. Hemos establecido los niveles sanguíneos del péptido intestinal vasoactivo (VIP), de la sustancia P, de la somatostatina (SS), y de la motilina en 50 determinaciones en 37 pacientes con feocromocitomas; 21 malignos, 10 benignos intra-adrenales, y 6 ectópicos (5 paracardiales y 1 perirrenal). Se consideró que los niveles hormonales estaban elevados cuando el nivel era de más de 3 de desviación estandar sobre el valor promedio en 52 individuos normales. De 37 pacientes, 20 (54%) presentaron un valor anormal en 1 o más determinaciones del nivel de hormonas intestinales. La anormalidad más común fue la elevación de la SS en 9/37 (24%). Además de esto, sinembargo, otros 3 (8%) presentaban elevación de VIP, 5 (13.5%) elevación de sustancia P. Los adenomas suprarrenales benignos exhibieron niveles elevados de SS y de sustancia P. Los feocromocitomas ectópicos demostraron producción sólo de SS además de catecolaminas, pero los feocromocitomas malignos demostraron ser capaces de secretar todos los 4 péptidos, y más de 1 en el mismo paciente. Hemos llegado a la conclusión de que los feocromocitomas pueden secretar múltiples peptidos vasoactivos y que ésto tiende a ocurrir cuando son malignos. La SS es el péptido más frecuentemente secretado y se lo encuentra en los tumores suprarrenales benigno y ectópico (paracardiacos). Si se encuentran niveles elevados de más de 1 péptido, la posibilidad de malignidad aparece significativamente aumentada.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41274/1/268_2005_Article_BF01655534.pd

Search for strong gravity in multijet final states produced in pp collisions at √s=13 TeV using the ATLAS detector at the LHC

A search is conducted for new physics in multijet final states using 3.6 inverse femtobarns of data from proton-proton collisions at √s = 13TeV taken at the CERN Large Hadron Collider with the ATLAS detector. Events are selected containing at least three jets with scalar sum of jet transverse momenta (HT) greater than 1TeV. No excess is seen at large HT and limits are presented on new physics: models which produce final states containing at least three jets and having cross sections larger than 1.6 fb with HT > 5.8 TeV are excluded. Limits are also given in terms of new physics models of strong gravity that hypothesize additional space-time dimensions