Parasitoids of \u3ci\u3eChionaspis Pinifoliae\u3c/i\u3e (Homoptera: Diaspididae) in Iowa

Three parasitoids (Hymenoptera: Encyrtidae: Aphelininae), Aphytis diaspidis, Coccobius varicornis, and Marietta pulchella, were recovered from field collections of the pine needle scale, Chionaspis pinifoliae, on Pinus sylvestris in central Iowa. Parasitoid mean time (± SEM) to emergence from overwintered scale mummies occurred at 46.6 (4.6) and 23.9 (1.3) days for C. varicornis and M. pulchella, respectively, using a 16L:8D photoperiod and a corresponding temperature regime of 22°C and 18°C. Growing-season parasitism level on field-collected female C. pinifoliae was 15%; parasitoid community composition was 86% A. diaspidis, 12% C. varicornis, and 2% M. pulchella

Toroidal Spiral Nambu-Goto Strings around Higher-Dimensional Black Holes

We present solutions of the Nambu-Goto equation for test strings in a shape of toroidal spiral in five-dimensional spacetimes. In particular, we show that stationary toroidal spirals exist around the five-dimensional Myers-Perry black holes. We also show the existence of innermost stationary toroidal spirals around the five-dimensional black holes like geodesic particles orbiting around four-dimensional black holes.Comment: 9 pages, 5 figure

Dynamics of Toroidal Spiral Strings around Five-dimensional Black Holes

We examine the separability of the Nambu-Goto equation for test strings in a shape of toroidal spiral in a five-dimensional Kerr-AdS black hole. In particular, for a `{\it Hopf loop}\rq string which is a special class of the toroidal spiral strings, we show the complete separation of variables occurs in two cases, Kerr background and Kerr-AdS background with equal angular momenta. We also obtain the dynamical solution for the Hopf loop around a black hole and for the general toroidal spiral in Minkowski background.Comment: 16 pages, 1 figure, minor changes, references adde

Vector Positronium States in QED3

The homogeneous Bethe-Salpeter equation is solved in the quenched ladder approximation for the vector positronium states of 4-component quantum electrodynamics in 2 space and 1 time dimensions. Fermion propagator input is from a Rainbow approximation Dyson-Schwinger solution, with a broad range of fermion masses considered. This work is an extension of earlier work on the scalar spectrum of the same model. The non-relativistic limit is also considered via the large fermion mass limit. Classification of states via their transformation properties under discrete parity transformations allows analogies to be drawn with the meson spectrum of QCD.Comment: 24 pages, 2 encapsulated postscript figure

Stationary Rotating Strings as Relativistic Particle Mechanics

Stationary rotating strings can be viewed as geodesic motions in appropriate metrics on a two-dimensional space. We obtain all solutions describing stationary rotating strings in flat spacetime as an application. These rotating strings have infinite length with various wiggly shapes. Averaged value of the string energy, the angular momentum and the linear momentum along the string are discussed.Comment: 20pages, 7 figure

Gauge covariance and the fermion-photon vertex in three- and four- dimensional, massless quantum electrodynamics

In the quenched approximation, the gauge covariance properties of three vertex Ans\"{a}tze in the Schwinger-Dyson equation for the fermion self energy are analysed in three- and four- dimensional quantum electrodynamics. Based on the Cornwall-Jackiw-Tomboulis effective action, it is inferred that the spectral representation used for the vertex in the gauge technique cannot support dynamical chiral symmetry breaking. A criterion for establishing whether a given Ansatz can confer gauge covariance upon the Schwinger-Dyson equation is presented and the Curtis and Pennington Ansatz is shown to satisfy this constraint. We obtain an analytic solution of the Schwinger-Dyson equation for quenched, massless three-dimensional quantum electrodynamics for arbitrary values of the gauge parameter in the absence of dynamical chiral symmetry breaking.Comment: 17 pages, PHY-7143-TH-93, REVTE

Nucleon form factors and a nonpointlike diquark

Nucleon form factors are calculated on q^2 in [0,3] GeV^2 using an Ansatz for the nucleon's Fadde'ev amplitude motivated by quark-diquark solutions of the relativistic Fadde'ev equation. Only the scalar diquark is retained, and it and the quark are confined. A good description of the data requires a nonpointlike diquark correlation with an electromagnetic radius of 0.8 r_pi. The composite, nonpointlike nature of the diquark is crucial. It provides for diquark-breakup terms that are of greater importance than the diquark photon absorption contribution.Comment: 5 pages, REVTEX, epsfig, 3 figure

Patients with Diabetic Nephropathy in Established Renal Failure: Demographics, Survival and Biochemical Variables (Chapter 16)

Diabetic nephropathy is now the most common renal disease leading to renal replacement therapy in developed countries1,2,3,4. Within the UK, the number of DN patients accepted for RRT rose steadily in the 1990s5 especially in the African–Caribbean and South Asian populations3,4,5,6. This may be related to the increased prevalence of Type 2 diabetes in the general population, the ageing population and the liberalisation of attitudes to acceptance for RRT5,7. The overall rise has slowed in the last 4 years8 . DN patients starting RRT are likely to have more co-morbidity than other patients, in particular cardiovascular disease, and consequently worse survival on RRT9,10,11. In recent years there has been some reduction in the high mortality of such patients, so the prevalence of diabetic nephropathy patients on RRT (currently lower than the percentage of incident patients, see Chapter 3) might increase12,13. The National Service Frameworks for Diabetes14 and for Renal Services15 have highlighted the importance of the primary prevention of DN in diabetic patients by early detection and aggressive management of hypertension, glucose control and cardiovascular risk factors and of the timely referral (recommendation >1 yr before RRT) of those with progressive renal disease in order to plan for RRT. 251 There is a key policy drive to reduce health inequalities in England16. In the UK there is evidence that diabetic patients in more socially deprived areas have higher all cause mortality even after adjustment for smoking and blood pressure9 , and lower rates of attendance at GP and hospital clinics17. The UK Renal Registry 2003 Report highlighted the possible role of social deprivation in the context of DN. This chapter examines the characteristics of patients developing established renal failure from DN, their access to modalities of treatment and their survival on RRT relative to other incident patients. It also includes data on quality of care (HbA1c, cholesterol and blood pressure). These analyses were undertaken before individual patient data from the Scottish Registry became available and therefore only includes England and Wales

The analytic structure of heavy quark propagators

The renormalised quark Dyson-Schwinger equation is studied in the limit of the renormalised current heavy quark mass m_R --> infinity. We are particularly interested in the analytic pole structure of the heavy quark propagator in the complex momentum plane. Approximations in which the quark-gluon vertex is modelled by either the bare vertex or the Ball-Chiu Ansatz, and the Landau gauge gluon propagator takes either a gaussian form or a gaussian form with an ultraviolet asymptotic tail are used.Comment: 21 pages Latex and 5 postscript figures. The original version of this paper has been considerably extended to include a formalism dealing with the renormalised heavy quark Dyson-Schwinger equation and uses a more realistic Ansatz for the gluon propagator

Strong Decays of Light Vector Mesons

The vector meson strong decays rho-->pi pi, phi-->KK, and K^star-->pi K are studied within a covariant approach based on the ladder-rainbow truncation of the QCD Dyson--Schwinger equation for the quark propagator and the Bethe--Salpeter equation for the mesons. The model preserves the one-loop behavior of QCD in the ultraviolet, has two infrared parameters, and implements quark confinement and dynamical chiral symmetry breaking. The 3-point decay amplitudes are described in impulse approximation. The Bethe--Salpeter study motivates a method for estimating the masses for heavier mesons within this model without continuing the propagators into the complex plane. We test the accuracy via the rho, phi and K^{star} masses and then produce estimates of the model results for the a_1 and b_1 masses as well as the mass of the proposed exotic vector pi_1(1400).Comment: Submitted for publication; 10x2-column pages, REVTEX 4, 3 .eps files making 3fig