Coccidiosis of Goats in Florida, USA

ABSTRACT Fecal samples from 277 goats on eleven farms in Florida were examined to determine the prevalence and intensity of the multiple species of Eimeria that infect goats in this region. The number of oocysts per gram of feces (OPG) was determined by the modified McMaster technique. Species identification was done following sporulation. Eimeria oocysts were found in 97% of the fecal samples. Goats less than one year of age shed significantly more oocysts than goats greater than one year of age (P < 0.01). Goats of the Nubian breed had the highest OPG counts when compared to Boer, Boer-Spanish crosses, and Saanen breeds. Nine Eimeria spp. were identified. Eimeria arloingi (91%), E. ninakohlyakimovae (82%) and E. alijevi (79%) were the most prevalent species. Other species present were E. caprina (60%), E. christenseni (60%), E. hirci (46%), E. caprovina (29%), E. aspheronica (15%), and E. jolchijevi (9%)

High-Energy gamma-ray Astronomy and String Theory

There have been observations, first from the MAGIC Telescope (July 2005) and quite recently (September 2008) from the FERMI Satellite Telescope, on non-simultaneous arrival of high-energy photons from distant celestial sources. In each case, the highest energy photons were delayed, as compared to their lower-energy counterparts. Although the astrophysics at the source of these energetic photons is still not understood, and such non simultaneous arrival might be due to non simultaneous emission as a result of conventional physics effects, nevertheless, rather surprisingly, the observed time delays can also fit excellently some scenarios in quantum gravity, predicting Lorentz violating space-time "foam" backgrounds with a non-trivial subluminal vacuum refractive index suppressed linearly by a quantum gravity scale of the order of the reduced Planck mass. In this pedagogical talk, I discuss the MAGIC and FERMI findings in this context and I argue on a theoretical model of space-time foam in string/brane theory that can accommodate the findings of those experiments in agreement with all other stringent tests of Lorentz invariance. However, I stress the current ambiguities/uncertainties on the source mechanisms, which need to be resolved first before definite conclusions are reached regarding quantum gravity foam scenarios.Comment: 34 pages latex, 12 eps figures incorporated, uses special macros. Based on invited plenary talk at DICE 2008 Conference (Castiglioncello, Italy), September 22-26 200

Quark phases in neutron stars and a "third family" of compact stars as a signature for phase transitions

The appearance of quark phases in the dense interior of neutron stars provides one possibility to soften the equation of state (EOS) of neutron star matter at high densities. This softening leads to more compact equilibrium configurations of neutron stars compared to pure hadronic stars of the same mass. We investigate the question to which amount the compactness of a neutron star can be attributed to the presence of a quark phase. For this purpose we employ several hadronic EOS in the framework of the relativistic mean-field (RMF) model and an extended MIT bag model to describe the quark phase. We find that - almost independent of the model parameters - the radius of a pure hadronic neutron star gets typically reduced by 20-30% if a pure quark phase in the center of the star does exist. For some EOS we furthermore find the possibility of a "third family" of compact stars which may exist besides the two known families of white dwarfs and neutron stars. We show how an experimental proof of the existence of a third family by mass and radius measurements may provide a unique signature for a phase transition inside neutron stars.Comment: 37 pages, 18 eps-figures included, LaTe

GoSam: A program for automated one-loop Calculations

The program package GoSam is presented which aims at the automated calculation of one-loop amplitudes for multi-particle processes. The amplitudes are generated in terms of Feynman diagrams and can be reduced using either D-dimensional integrand-level decomposition or tensor reduction, or a combination of both. GoSam can be used to calculate one-loop corrections to both QCD and electroweak theory, and model files for theories Beyond the Standard Model can be linked as well. A standard interface to programs calculating real radiation is also included. The flexibility of the program is demonstrated by various examples.Comment: 10 pages, Talk given at the International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT), Uxbridge, London, September 201

Manejo de la Cotorra en Instalaciones Eléctricas en el sur de Florida

La cotorra común (Myiopsitta monachus) es un ave originaria de América del Sur pero se ha establecido en varios sitios a lo largo de los Estados Unidos mediante liberaciones premeditadas y también accidentales. La especie es única entre los loros pues no construye sus nidos en cavidades sino que construye una estructura de nidificación voluminosa con palos. A menudo, tanto en regiones donde es nativa y en los Estados Unidos, la cotorra selecciona las estructuras eléctricas como sitio de nidificación. El material del nido puede causar corto-circuitos que producen daños a la estructura y cortes de luz subsiguientes. En el sur de Florida, el daño causado por las cotorras y los cortes de luz asociados han aumentado substancialmente en los últimos años. Aunque el costo total asociado con el daño y los cortes de luz no se conocen, es evidente que los métodos actuales para manejar el problema son inadecuados. En el 2001, para responder a la necesidad de métodos de manejo más efectivos, la Compañía de Luz y Electricidad de Florida inició un proyecto para identificar e investigar alternativas de manejo nuevas y potencialmente útiles. En este trabajo, revisamos el conocimiento actual sobre los impactos de las cotorras en las estructuras eléctricas y discutimos el estado de la investigación para desarrollar nuevos métodos para reducir estos impactos

Dynamical Evolution of the Scalar Condensate in Heavy Ion Collisions

We derive the effective coarse-grained field equation for the scalar condensate of the linear sigma model in a simple and straightforward manner using linear response theory. The dissipative coefficient is calculated at tree level on the basis of the physical processes of sigma-meson decay and of thermal sigma-mesons and pions knocking sigma-mesons out of the condensate. The field equation is solved for hot matter undergoing either one or three dimensional expansion and cooling in the aftermath of a high energy nuclear collision. The results show that the time constant for returning the scalar condensate to thermal equilibrium is of order 2 fm/c.Comment: 19 pages, 3 figures are embedded at the end. The effect of the time dependence of the condensate v is included in this revised version. Numerical work is redone accordingl

Gluon fusion contribution to W+W- + jet production

We describe the computation of the $gg \to W^+W^-g$ process that contributes to the production of two $W$-bosons and a jet at the CERN Large Hadron Collider (LHC). While formally of next-to-next-to-leading order (NNLO) in QCD, this process can be evaluated separately from the bulk of NNLO QCD corrections because it is finite and gauge-invariant. It is also enhanced by the large gluon flux and by selection cuts employed in the Higgs boson searches in the decay channel $H \to W^+W^-$, as was first pointed out by Binoth {\it et al.} in the context of $gg \to W^+W^-$ production. For cuts employed by the ATLAS collaboration, we find that the gluon fusion contribution to $pp \to W^+W^-j$ enhances the background by about ten percent and can lead to moderate distortions of kinematic distributions which are instrumental for the ongoing Higgs boson searches at the LHC. We also release a public code to compute the NLO QCD corrections to this process, in the form of an add-on to the package {\tt MCFM}.Comment: 13 pages, 4 figures, 3 table

The influence of medium effects on the gross structure of hybrid stars

We investigate the influence of medium effects on the structure of hybrid stars, i.e. neutron stars possessing a quark matter core. We found that medium effects reduce the extent of a pure quark matter phase in the interior of a hybrid star significantly in favor of a mixed phase of quark and hadronic matter. Over a wide range of the strong coupling constant - which parameterizes the influence of medium effects - quark matter is able to exist at least in a mixed phase in the interior of neutron stars.Comment: 20 pages, LaTeX, 4 inline eps-figures, 4 gif-figures, extended discussion, to be published in Nucl. Phys. A. Also available at http://theorie.physik.uni-giessen.de/~schertle/HybSta

Thermal rates for baryon and anti-baryon production

We use a form of the fluctuation-dissipation theorem to derive formulas giving the rate of production of spin-1/2 baryons in terms of the fluctuations of either meson or quark fields. The most general formulas do not assume thermal or chemical equilibrium. When evaluated in a thermal ensemble we find equilibration times on the order of 10 fm/c near the critical temperature in QCD.Comment: 22 pages, 4 tables and 2 figures, REVTe

A stopped Delta-Matter Source in Heavy Ion Collisions at 10 GeV/n

We predict the formation of highly dense baryon-rich resonance matter in Au+Au collisions at AGS energies. The final pion yields show observable signs for resonance matter. The Delta(1232) resonance is predicted to be the dominant source for pions of small transverse momenta. Rescattering effects -- consecutive excitation and deexcitation of Deltas -- lead to a long apparent lifetime (> 10 fm/c) and rather large volumina (several 100 fm^3) of the Delta-matter state. Heavier baryon resonances prove to be crucial for reaction dynamics and particle production at AGS.Comment: 17 pages, 5 postscript figures, uses psfig.sty and revtex.st