A Comprehensive Survey of Brane Tilings

An infinite class of $4d$ $\mathcal{N}=1$ gauge theories can be engineered on the worldvolume of D3-branes probing toric Calabi-Yau 3-folds. This kind of setup has multiple applications, ranging from the gauge/gravity correspondence to local model building in string phenomenology. Brane tilings fully encode the gauge theories on the D3-branes and have substantially simplified their connection to the probed geometries. The purpose of this paper is to push the boundaries of computation and to produce as comprehensive a database of brane tilings as possible. We develop efficient implementations of brane tiling tools particularly suited for this search. We present the first complete classification of toric Calabi-Yau 3-folds with toric diagrams up to area 8 and the corresponding brane tilings. This classification is of interest to both physicists and mathematicians alike.Comment: 39 pages. Link to Mathematica modules provide

The Quark Propagator from the Dyson-Schwinger Equations: I. the Chiral Solution

Within the framework of the Dyson-Schwinger equations in the axial gauge, we study the effect that non-perturbative glue has on the quark propagator. We show that Ward-Takahashi identities, combined with the requirement of matching perturbative QCD at high momentum transfer, guarantee the multiplicative renormalisability of the answer. Technically, the matching with perturbation theory is accomplished by the introduction of a transverse part to the quark-gluon vertex. We show that this transverse vertex is crucial for chiral symmetry breaking, and that massless solutions exist below a critical value of the strong coupling constant. Using the gluon propagator that we previously calculated, we obtain small corrections to the quark propagator, which keeps a pole at the origin in the chiral phase.Comment: 21 pages, 6 figures; McGill/94-24, SHEP 93/94-26 We generalise our results by showing that they are not sensitive to the specific choice that we make for the transverse vertex. We illustrate that fact in two new figure

Ralgro-implanted bulls: Performance, carcass characteristics, longissimus palatability and carcass electrical stimulation

Twenty of 40 Angus bulls were implanted (I) five times with 36 mg of Ralgro| at average intervals of 106 d, beginning near birth. All bulls and their dams were on bluestem pasture initially and, at an average age of 320 d bulls were fed a concentrate diet until they were slaughtered, weighing either 454 or 499 kg. One side of each carcass was electrically stimulated. Average daily gain and feed efficiency of I bulls improved 6.5 to 10.4% and 7.9 to 8.1%, respectively, depending upon the end point comparison with nonimplanted (NI) bulls. Implanted bulls attained their slaughter weights 42 d sooner than did NI bulls. Implantation decreased (P<.05) penis weight and length, testicle weight, volume and density, but did not affect (P>.05) seminal vesicle and pituitary weights. Carcasses from I bulls had more (P<.05) skeletal ossification and were fatter than carcasses from NI bulls. Marbling scores, quality grades and longissimus cooking losses and juiciness scores were not affected (P>.05) by implantation. Taste panel flavor intensity and detectable connective tissue scores were higher (P<.05) for steaks from I bulls than from NI bulls. Longissimus steak tenderness evaluations were higher (P<.05) for both I slaughter groups than for the NI light-weight group and were higher (P<.05) for the I lightweight group than for the NI heavy-weight group. Longissimus tenderness tended (P = .11) to be higher for steaks from the I heavy-weight group than those from the NI heavy-weight group. Electrical stimulation produced (P<.05) a softer, coarser textured lean, but it did not affect lean color, marbling or quality grade. Steaks from electrically stimulated sides tended to have higher (P = .09) myofibrillar tenderness scores and lower (P = .06) flavor scores than steaks from nonstimulated sides

Nonperturbative Renormalization and the QCD Vacuum

We present a self consistent approach to Coulomb gauge Hamiltonian QCD which allows one to relate single gluon spectral properties to the long range behavior of the confining interaction. Nonperturbative renormalization is discussed. The numerical results are in good agreement with phenomenological and lattice forms of the static potential.Comment: 23 pages in RevTex, 4 postscript figure

Opieka paliatywna oraz opieka końcowego okresu życia u chorych na ciężką postać POChP

Przewlekła obturacyjna choroba płuc (POChP) jest jedną z głównych przyczyn chorobowości i umieralności. U wielu chorych maksymalne leczenie POChP pozwala osiągnąć jedynie niewielką lub niepełną poprawę objawów chorobowych, które znacznie pogarszają jakość życia. Pomimo wysokiej chorobowości i umieralności związanej z ciężką postacią POChP, wielu chorych nie otrzymuje właściwego leczenia paliatywnego. Wynika to z kilku powodów. Po pierwsze, komunikacja między lekarzem a chorym, dotycząca opieki paliatywnej oraz opieki końcowego okresu życia, jest zwykle sporadyczna i złej jakości. Po drugie, niepewność dotycząca dalszego rokowania u chorych na POChP dodatkowo utrudnia komunikację w końcowym okresie życia. W rezultacie chorzy i ich bliscy często nie rozumieją, że ciężka postać POChP jest z reguły postępującą i śmiertelną chorobą. Celem niniejszego przeglądu jest podsumowanie ostatnich badań dotyczących opieki paliatywnej oraz opieki końcowego okresu życia chorych na POChP. Wyniki niedawnych badań dostarczają nowych zaleceń postępowania w poprawianiu komunikacji między lekarzem a pacjentem dotyczącej leczenia w końcowym okresie życia. Dzięki przestrzeganiu tych zaleceń poprawia się także jakość leczenia paliatywnego oraz leczenia końcowego okresu życia chorych na POChP. Szczególną uwagę zwrócono na dwa obszary, które mogą wpływać na poprawę jakości leczenia paliatywnego i leczenia końcowego okresu życia: 1) rolę smutku i depresji, częstych problemów chorych na POChP; oraz 2) potrzebę wczesnego planowania opieki nad chorym. Poprawa komunikacji między chorym a lekarzem jest istotna dla jakości opieki paliatywnej

Total positivity: tests and parametrizations

An introduction to total positivity (TP), with the emphasis on efficient TP criteria and parametrizations of TP matrices. Intended for general mathematical audience.Comment: 20 pages, with color figure

A Model for the Reduction of Specific Surface Area of Powders with Age

PETN is a high explosive, sometimes stored for periods of up to many years, in powdered form. In storage, the explosive particles change size and shape owing to sublimation, condensation and surface di usion. AWE measurements are available on the changing particle size distri- bution (PSD), and the speci c surface area (SSA) of the powder, taken from experiments on accelerated ageing. But a mathematical model of the ageing process is wanted in order to interpret the processes at work. Various modelling issues and unusual features of the measure- ment data were discussed. Four models of important processes were developed, and are reported here. Model (i) addresses the fundamental physics associated with the transport of mass by sublimation, di usion and condensation. Model (ii) uses chemical kinetics to develop a system of ordinary di erential equations (ODEs) for the time-evolution of the frequencies of particle sizes. Model (iii) extends Model (ii) to a contin- uum particle size distribution. Lastly, Model (iv) considers the growth of particles as described by Cahn-Hilliard equations for the inter-particle transport of matter in Ostwald Ripening. Models (i) and (iv) include the complex geometry and thermodynamics of the problem. By con- trast, Models (ii) and (iii) focus on the time evolution of the PSD, but they are more di cult to associate with controllable variables, such as ambient temperature. Our discussions of models (ii) and (iii) suggest we can choose mass-transfer rate constants that reproduce the kind of ob- served evolution to a bimodal PSD. But more investigation is needed to determine how the rate constants may be associated with the particles' geometry and the thermodynamics of the mass transport processes

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

Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table, matches published version in Physical Review