The Coupled Cluster Method in Hamiltonian Lattice Field Theory

The coupled cluster or exp S form of the eigenvalue problem for lattice Hamiltonian QCD (without quarks) is investigated. A new construction prescription is given for the calculation of the relevant coupled cluster matrix elements with respect to an orthogonal and independent loop space basis. The method avoids the explicit introduction of gauge group coupling coefficients by mapping the eigenvalue problem onto a suitable set of character functions, which allows a simplified procedure. Using appropriate group theoretical methods, we show that it is possible to set up the eigenvalue problem for eigenstates having arbitrary lattice momentum and lattice angular momentum.Comment: LaTeX, no figur

Use of ultrasonographic examination in sheep veterinary practice

This review describes the current, emerging and potential applications of ultrasonography in the field of first-opinion sheep veterinary practice. The most widespread application is pregnancy diagnosis, where both transrectal and transabdominal ultrasonography offer a highly sensitive tool for, among others, detection of pregnancy, identification of foetal number and diagnosis of uterine abnormalities, e.g., metritis. The diagnostic applications of ultrasonography for imaging the lungs, heart, male genitourinary system and superficial swellings are also described. Through review of recent research in sheep and by analogy from applications in other animal species, the potential role of ultrasonography in screening programmes for cystic echinococcosis or ovine pulmonary adenocarcinoma, diagnosis of ocular and laryngeal disease and localisation of Coenurus cysts is explored

A New Finite-lattice study of the Massive Schwinger Model

A new finite lattice calculation of the low lying bound state energies in the massive Schwinger model is presented, using a Hamiltonian lattice formulation. The results are compared with recent analytic series calculations in the low mass limit, and with a new higher order non-relativistic series which we calculate for the high mass limit. The results are generally in good agreement with these series predictions, and also with recent calculations by light cone and related techniques

Density Matrix Renormalisation Group Approach to the Massive Schwinger Model

The massive Schwinger model is studied, using a density matrix renormalisation group approach to the staggered lattice Hamiltonian version of the model. Lattice sizes up to 256 sites are calculated, and the estimates in the continuum limit are almost two orders of magnitude more accurate than previous calculations. Coleman's picture of `half-asymptotic' particles at background field theta = pi is confirmed. The predicted phase transition at finite fermion mass (m/g) is accurately located, and demonstrated to belong in the 2D Ising universality class.Comment: 38 pages, 18 figures, submitted to PR

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

Evolocumab in Pediatric Heterozygous Familial Hypercholesterolemia

BACKGROUND Evolocumab, a fully human monoclonal antibody directed against proprotein convertase subtilisin–kexin type 9, is widely used in adult patients to lower low-density lipoprotein (LDL) cholesterol levels. Its effects in pediatric patients with heterozygous familial hypercholesterolemia are not known. METHODS We conducted a 24-week, randomized, double-blind, placebo-controlled trial to evaluate the efficacy and safety of evolocumab in pediatric patients with heterozygous familial hypercholesterolemia. Patients 10 to 17 years of age who had received stable lipid-lowering treatment for at least 4 weeks before screening and who had an LDL cholesterol level of 130 mg per deciliter (3.4 mmol per liter) or more and a triglyceride level of 400 mg per deciliter (4.5 mmol per liter) or less were randomly assigned in a 2:1 ratio to receive monthly subcutaneous injections of evolocumab (420 mg) or placebo. The primary end point was the percent change in LDL cholesterol level from baseline to week 24; key secondary end points were the mean percent change in LDL cholesterol level from baseline to weeks 22 and 24 and the absolute change in LDL cholesterol level from baseline to week 24. RESULTS A total of 157 patients underwent randomization and received evolocumab (104 patients) or placebo (53 patients). At week 24, the mean percent change from baseline in LDL cholesterol level was −44.5% in the evolocumab group and −6.2% in the placebo group, for a difference of −38.3 percentage points (P<0.001). The absolute change in the LDL cholesterol level was −77.5 mg per deciliter (−2.0 mmol per liter) in the evolocumab group and −9.0 mg per deciliter (−0.2 mmol per liter) in the placebo group, for a difference of −68.6 mg per deciliter (−1.8 mmol per liter) (P<0.001). Results for all secondary lipid variables were significantly better with evolocumab than with placebo. The incidence of adverse events that occurred during the treatment period was similar in the evolocumab and placebo groups. CONCLUSIONS In this trial involving pediatric patients with familial hypercholesterolemia, evolocumab reduced the LDL cholesterol level and other lipid variables. (Funded by Amgen; HAUSER-RCT ClinicalTrials.gov number, NCT02392559. opens in new tab.

Life after logging in tropical forests of Borneo: A meta-analysis

Selectively logged tropical forests retain high species richness and functional diversity, but species composition changes after logging, suggesting that some species are more vulnerable to logging than others. We did a meta-analysis to summarise the effect of logging on the abundance of individual bird and mammal species in tropical forests of Borneo, which have suffered some of the most intense selective logging in the tropics. We found that species classified by the International Union for Conservation of Nature (IUCN) as ‘vulnerable’ or ‘near-threatened’ are generally less abundant in logged tropical forests than those classified as ‘least concern’. However, the effect of logging within each IUCN category is variable, indicating that logging is not the only or main cause of decline in abundance. While our results show that closely related species responded similarly to logging, in birds there was significant variation between responses of some closely related species. Bigger species were significantly more susceptible to logging than smaller species in both birds and mammals. We also found that cavity-nesting birds suffered more from logging than did other species. Our results highlight the importance of identifying which factors lead individual species to flourish or suffer in logged tropical forests