New Host-plant Records For Neotropical Agromyzids (diptera: Agromyzidae) From Asteraceae Flower Heads

Agromyzidae is a large and cosmopolitan fly family with approximately 2,500 known species. Here we present 22 new records of agromyzid-host plant associations. Plants were sampled from 2002 to 2005 in São Paulo state, Brazil. A total of eight agromyzid species were reared from 18 Asteraceae host species. The genus Melanagromyza Hendel was the commonest. This is the first detailed study reporting associations between non-leafmining Agromyzidae and their host plants in Brazil.3719799Almeida, A.M., C.R. Fonsceca, P.I. Prado, M. Almeida Neto, S. Diniz, U. Kubota, M.R. Braun, R.L.G. Raimundo, L.A. Anjos, T.G. Mendonça, S.M. Futada & T.M. Lewinsohn. 2005. Diversidade e ocorrência de Asteraceae em cerrados de São Paulo. Biota Neotrop. 5: http://www.biotaneotropica. org.br/v5n2/pt/abstract?article+BN00105022005 . ISSN 1676-0603Andersen, A., Sjursen, H., Rafoss, T., Biodiversity of Agromizydae (Diptera) and biologically and conventionally grown spring barley and grass field (2004) Biol. Agric. Hortic, 22, pp. 143-155Benavent-Corai, J., Martinez, M., Jimenez Peydró, R., Catalogue of the host-plants of the world Agromyzidae (Diptera) (2005) Boll. Zool. Agrar. Bachic. Serie II, 37, pp. 1-97Bremer, K., (1994) Asteraceae: Cladistics and classification, , Timber Press, Portland, 752pChen, X., Lang, F., Xu, Z., He, J., Ma, Y., The occurrence of leafminers and their parasitoids on vegetables and weeds in Hangzhou area, Southeast China (2003) BioControl, 48, pp. 515-527Eiten, G., Cerrado vegetation of Brazil (1972) Bot. Rev, 38, pp. 201-341Fonseca, C.R., Prado, P.I., Almeida Neto, M., Kubota, U., Lewinsohn, T.M., Flower heads, herbivores, and their parasitoids: Food web structure along a fertility gradient (2005) Ecol. Entomol, 30, pp. 36-46Gagné, R.J., (1994) The gall midges of the Neotropical region, , Cornell Univ. Press, Ithaca, 352pLewinsohn, T.M. 1991. Insects in flower heads of Asteraceae in southeast Brazil: a case study on tropical species richness, p.525-560. In P.W. Price, T.M. Lewinsohn, G.W. Fernandes & W.W. Benson (eds.). Plant-animal interactions: Evolutionary ecology in tropical and temperate regions. John Wiley & Sons, Inc., New York, 639pLewinsohn, T.M., Novotny, V., Basset, Y., Insects on plants: Diversity of herbivore assemblages revisited (2005) Annu. Rev. Ecol. Syst, 36, pp. 597-620Schuster, D.J., Gilreath, J.P., Wharton, R.A., Seymour, P.R., Agromyzidae (Diptera) leafminers and their parasitoids in weeds associated with potato in Florida (1991) Environ. Entomol, 20, pp. 720-723Spencer, K.A., Notes on the Neotropical Agromyzidae (Diptera) (1966) Pap. Avulsos Zool, 19, pp. 142-150Spencer, K.A., The Agromyzidae of Canada and Alaska (1969) Mem. Entomol. Soc. Can, 64, pp. 1-311Spencer, K.A. 1973a. Agromyzidae (Diptera) of economic importance. Dr. W. Junk B. V. The Hague, Serie Entomologica, 418pSpencer, K.A., The Agromyzidae (Diptera) of Venezuela. Rev. Fac. Agrom (1973), pp. 5-107. , Mar. VIIISpencer, K.A., (1990) Host specialization in the world Agromyzidae, , Diptera, Kluwer Academic Publishers, Dordrecht, 444pSpencer, K.A. 1996. Australasian/Oceanian Diptera Catalog - Web Version. URL: http://hbs.bishopmuseum.org/aocat/agromyzidae.html. Accessed in 12/09/2006Spencer, K.A. & C.E. Stegmaier. 1973. Arthropods of Florida (EUA) and neighboring land areas, v. 7. Agromyzidae of Florida (USA) with a Supplement on Species from the Caribbean. Fla. Dep. Agri. Cons. Serv., Gainesville, 205pSpencer, K.A. & G.C. Steyskal. 1986. Manual of the Agromyzidae (Diptera) of the United States. U. S. Department of Agriculture, Agriculture Handbook. n. 638. Washington, U.S.ASpencer, K.A., Martinez, M., Etienne, J., Les Agromyzidae (Diptera) de Guadeloupe. (1992) Ann. Soc. Entomol. Fr, 28, pp. 251-302Zwölfer, H. 1988. Species richness, species packing, and evolution in insect-plant systems, p.301-319. In E.D. Schulze & H. Zwölfer (eds.), Potentials and limitations of ecosystem analysis. Springer-Verlag. Berlin, 435

Multi-Channel Inverse Scattering Problem on the Line: Thresholds and Bound States

We consider the multi-channel inverse scattering problem in one-dimension in the presence of thresholds and bound states for a potential of finite support. Utilizing the Levin representation, we derive the general Marchenko integral equation for N-coupled channels and show that, unlike to the case of the radial inverse scattering problem, the information on the bound state energies and asymptotic normalization constants can be inferred from the reflection coefficient matrix alone. Thus, given this matrix, the Marchenko inverse scattering procedure can provide us with a unique multi-channel potential. The relationship to supersymmetric partner potentials as well as possible applications are discussed. The integral equation has been implemented numerically and applied to several schematic examples showing the characteristic features of multi-channel systems. A possible application of the formalism to technological problems is briefly discussed.Comment: 19 pages, 5 figure

The deconfined phase near Tc and its decay into hadrons

We sketch an effective theory for the deconfined state of QCD near Tc. This relates the behavior of the expectation value of the Polyakov loop, and its two-point functions, to the pressure. Defining the ``mass'' of three and two gluon states from the imaginary and real parts of the Polyakov loop, while this ratio is 3:2 in perturbation theory, at Tc it is 3:1. We also discuss the decay of the deconfined state into hadrons.Comment: 4 pages, no figures, Contribution to the Proceedings of "Quark Matter 2002", Nantes, France, 18-24 Jul 200

Pion dispersion relation at finite density and temperature

We study the behavior of the pion dispersion relation in a pion medium at finite density and temperature. We introduce a pion chemical potential to describe the finite pion number density and argue that such description is valid during the hadronic phase of a relativistic heavy-ion collision between chemical and thermal freeze-out. We make use of an effective Lagrangian that explicitly respects chiral symmetry through the enforcement of the chiral Ward identities. The pion dispersion relation is computed through the computation of the pion self-energy in a non-perturbative fashion by giving an approximate solution to the Schwinger-Dyson equation for this self-energy. The dispersion relation is described in terms of a density and temperature dependent mass and an index of refraction which is also temperature, density as well as momentum dependent. The index of refraction is larger than unity for all values of the momentum for finite $\mu$ and $T$. We conclude by exploring some of the possible consequences for the propagation of pions through the boundary between the medium and vacuum.Comment: 7 pages, 5 figures, 3 new references, published versio

An augmented Lagrangian decomposition method for quasi-separable problems in MDO

Several decomposition methods have been proposed for the distributed optimal design of quasi-separable problems encountered in Multidisciplinary Design Optimization (MDO). Some of these methods are known to have numerical convergence difficulties that can be explained theoretically. We propose a new decomposition algorithm for quasi-separable MDO problems. In particular, we propose a decomposed problem formulation based on the augmented Lagrangian penalty function and the block coordinate descent algorithm. The proposed solution algorithm consists of inner and outer loops. In the outer loop, the augmented Lagrangian penalty parameters are updated. In the inner loop, our method alternates between solving an optimization master problem, and solving disciplinary optimization subproblems. The coordinating master problem can be solved analytically; the disciplinary subproblems can be solved using commonly available gradient-based optimization algorithms. The augmented Lagrangian decomposition method is derived such that existing proofs can be used to show convergence of the decomposition algorithm to KKT points of the original problem under mild assumptions. We investigate the numerical performance of the proposed method on two example problems. I

Thermal fluctuations in the interacting pion gas

We derive the two-particle fluctuation correlator in a thermal gas of pi-mesons to the lowest order in an interaction due to a resonance exchange. A diagrammatic technique is used. We discuss how this result can be applied to event-by-event fluctuations in heavy-ion collisions, in particular, to search for the critical point of QCD. As a practical example, we determine the shape of the rapidity correlator.Comment: 12 pages, 4 figures, RevTe

Chiral-symmetry restoration in the linear sigma model at nonzero temperature and baryon density

We study the chiral phase transition in the linear sigma model with 2 quark flavors and $N_c$ colors. One-loop calculations predict a first-order phase transition at both $\mu=0$ and $\mu\neq 0$. We also discuss the phase diagram and make a comparison with a thermal parametrization of existing heavy-ion experimental data.Comment: 12 pages, 6 ps-figures, LaTe

Spectroscopy of resonance decays in high-energy heavy-ion collisions

Invariant mass distributions of the hadronic decay products from resonances formed in relativistic heavy ion collision (RHIC) experiments are investigated with a view to disentangle the effects of thermal motion and the phase space of decay products from those of intrinsic changes in the structure of resonances at the freeze-out conditions. Analytic results of peak mass shifts for the cases of both equal and unequal mass decay products are derived. The shift is expressed in terms of the peak mass and width of the vacuum or medium-modified spectral functions and temperature. Examples of expected shifts in meson (e.g., rho, omega, and sigma) and baryon (e.g., Delta) resonances that are helpful to interpret recent RHIC measurements at BNL are provided. Although significant downward mass shifts are caused by widened widths of the $\rho-$meson in medium, a downward shift of at least 50 MeV in its intrinsic mass is required to account for the reported downward shift of 60-70 MeV in the peak of the rho-invariant mass distribution. An observed downward shift from the vacuum peak value of the Delta distinctively signals a significant downward shift in its intrinsic peak mass, since unlike for the rho-meson, phase space functions produce an upward shift for the Delta isobar.Comment: published version with slight change of title and some typos corrected, 12 pages, 5 figure

Switching model with two habitats and a predator involving group defence

Switching model with one predator and two prey species is considered. The prey species have the ability of group defence. Therefore, the predator will be attracted towards that habitat where prey are less in number. The stability analysis is carried out for two equilibrium values. The theoretical results are compared with the numerical results for a set of values. The Hopf bifuracation analysis is done to support the stability results