A Model of Simultaneous Evolution of Competitive Ability and Herbivore Resistance in a Perennial Plant

Plant populations often experience the joint effects of intraspecific competition and herbivory, yet the impact of the interaction of these two factors on the outcome of evolution is largely unknown. Here, we develop a spatially explicit simulation model to examine interactions between the evolution of herbivore resistance and competitive ability in the goldenrod Solidago altissima. We define competitive ability as either competitive effect, the ability of a plant to deplete resources and make them unavailable to competitors, or competitive response, the ability to grow, survive, and reproduce despite depletion of resources by neighboring competitors. We considered symmetric and asymmetric modes of competition and explored the following questions: (1) Does the selective effect of competition differ for the two components of competitive ability? (2) What are the effects of the evolution of competitive ability and resistance on each other? (3) Can trade-offs between competitive ability and resistance emerge, given no relationship between these two traits prior to selection? Our results showed that competitive response evolved quickly regardless of the mode of competition, but self-suppression hindered the evolution of competitive effect. The evolution of resistance appeared to be independent of the evolution of competitive ability. Intraspecific competition was the major selective force in our model. At natural levels of herbivory, selection for resistance played a secondary role in structuring the population. Resistant genotypes were only favored at very low resistance costs. At high cost levels, the costs of maintaining resistance far outweighed the benefits. The selective forces of competition and herbivory resulted in trade-offs between competitive response and herbivore resistance, but only at low costs of resistance. Vigorous growth associated with a high competitive response might translate into trade-offs between herbivore tolerance and resistance. The strong selective effects of competitors, coupled with the weaker selection from herbivores, suggest that plant traits directly associated with growth that confer tolerance to both competitors and consumers may be the targets of selection

Root to Kellerer

We revisit Kellerer's Theorem, that is, we show that for a family of real probability distributions $(\mu_t)_{t\in [0,1]}$ which increases in convex order there exists a Markov martingale $(S_t)_{t\in[0,1]}$ s.t.\ $S_t\sim \mu_t$. To establish the result, we observe that the set of martingale measures with given marginals carries a natural compact Polish topology. Based on a particular property of the martingale coupling associated to Root's embedding this allows for a relatively concise proof of Kellerer's theorem. We emphasize that many of our arguments are borrowed from Kellerer \cite{Ke72}, Lowther \cite{Lo07}, and Hirsch-Roynette-Profeta-Yor \cite{HiPr11,HiRo12}.Comment: 8 pages, 1 figur

Determining the top-antitop and ZZZZ Couplings of a Neutral Higgs Boson of Arbitrary CP Nature at the NLC

The optimal procedure for extracting the coefficients of different components of a cross section which takes the form of unknown coefficients times functions of known kinematical form is developed. When applied to \epem\to t\anti t+Higgs production at \rts=1\tev and integrated luminosity of 200\fbi, we find that the t\anti t\toHiggs CP-even and CP-odd couplings and, to a lesser extent, the $ZZ\to$Higgs (CP-even) coupling can be extracted with reasonable errors, assuming the Higgs sector parameter choices yield a significant production rate. Indeed, the composition of a mixed-CP Higgs eigenstate can be determined with sufficient accuracy that a SM-like CP-even Higgs boson can be distinguished from a purely CP-odd Higgs boson at a high level of statistical significance, and vice versa.Comment: 8 pages, full postscript file also available via anonymous ftp at ftp://ucdhep.ucdavis.edu/gunion/eetottbh.p

Dallas with balls: televized sport, soap opera and male and female pleasures

Two of the most popular of television genres, soap opera and sports coverage have been very much differentiated along gender lines in terms of their audiences. Soap opera has been regarded very much as a 'gynocentric' genre with a large female viewing audience while the audiences for television sport have been predominantly male. Gender differentiation between the genres has had implications for the popular image of each. Soap opera has been perceived as inferior; as mere fantasy and escapism for women while television sports has been perceived as a legitimate, even edifying experience for men. In this article the authors challenge the view that soap opera and television sport are radically different and argue that they are, in fact, very similar in a number of significant ways. They suggest that both genres invoke similar structures of feeling and sensibility in their respective audiences and that television sport is a 'male soap opera'. They consider the ways in which the viewing context of each genre is related to domestic life and leisure, the ways in which the textual structure and conventions of each genre invoke emotional identification, and finally, the ways in which both genres re-affirm gender identities

Care For Pastors: Learning From Clergy and Their Spouses

Pastors and their spouses face unique challenges because of the nature of pastoral work, and yet most manage these challenges successfully. Five studies are presented which help distinguish between intrapersonal, family, and community forms of care. Pastors rely heavily on intrapersonal forms of coping such as spiritual devotion, hobbies, exercise, and taking time away from work. The marriage relationship is also quite important for most clergy and spouses. Relationships outside the immediate family are not commonly identified as coping resources. Implications are discussed

Three-Dimensional Quantum Percolation Studied by Level Statistics

Three-dimensional quantum percolation problems are studied by analyzing energy level statistics of electrons on maximally connected percolating clusters. The quantum percolation threshold \pq, which is larger than the classical percolation threshold \pc, becomes smaller when magnetic fields are applied, i.e., \pq(B=0)>\pq(B\ne 0)>\pc. The critical exponents are found to be consistent with the recently obtained values of the Anderson model, supporting the conjecture that the quantum percolation is classified onto the same universality classes of the Anderson transition. Novel critical level statistics at the percolation threshold is also reported.Comment: to appear in the May issue of J. Phys. Soc. Jp

Defect Formation and Critical Dynamics in the Early Universe

We study the nonequilibrium dynamics leading to the formation of topological defects in a symmetry-breaking phase transition of a quantum scalar field with \lambda\Phi^4 self-interaction in a spatially flat, radiation-dominated Friedmann-Robertson-Walker Universe. The quantum field is initially in a finite-temperature symmetry-restored state and the phase transition develops as the Universe expands and cools. We present a first-principles, microscopic approach in which the nonperturbative, nonequilibrium dynamics of the quantum field is derived from the two-loop, two-particle-irreducible closed-time-path effective action. We numerically solve the dynamical equations for the two-point function and we identify signatures of topological defects in the infrared portion of the momentum-space power spectrum. We find that the density of topological defects formed after the phase transition scales as a power law with the expansion rate of the Universe. We calculate the equilibrium critical exponents of the correlation length and relaxation time for this model and show that the power law exponent of the defect density, for both overdamped and underdamped evolution, is in good agreement with the "freeze-out" scenario of Zurek. We introduce an analytic dynamical model, valid near the critical point, that exhibits the same power law scaling of the defect density with the quench rate. By incorporating the realistic quench of the expanding Universe, our approach illuminates the dynamical mechanisms important for topological defect formation. The observed power law scaling of the defect density with the quench rate, observered here in a quantum field theory context, provides evidence for the "freeze-out" scenario in three spatial dimensions.Comment: 31 pages, RevTex, 8 figures in EPS forma