Percolation transition in networks with degree-degree correlation

We introduce an exponential random graph model for networks with a fixed degree distribution and with a tunable degree-degree correlation. We then investigate the nature of a percolation transition in the correlated network with the Poisson degree distribution. It is found that negative correlation is irrelevant in that the percolation transition in the disassortative network belongs to the same universality class of the uncorrelated network. Positive correlation turns out to be relevant. The percolation transition in the assortative network is characterized by the non-diverging mean size of finite clusters and power-law scalings of the density of the largest cluster and the cluster size distribution in the non-percolating phase as well as at the critical point. Our results suggest that the unusual type percolation transition in the growing network models reported recently may be inherited from the assortative degree-degree correlation.Comment: 7 pages, 11 figur

Community Partnerships in Urban, Title 1 Elementary Schools: A Mixed-Methods Study

The purpose of this mixed-methods study was to identify and describe community partnerships in Urban, Title 1 Elementary Schools. Fifty-one principals from the Southern and Midwestern regions of the United States completed a 19-question on-line survey designed to explore community partnerships in Urban, Title 1 Elementary Schools. Of the 51 principals who completed the survey, 26 agreed to participate in a semi-structured interview. The findings of the study suggest that community partnerships play an essential role in supporting Urban, Title 1 Elementary Schools. Finding community partners can be challenging. Principals who wish to engage community partners should identify the needs of the school prior to seeking community partners or implementing a community partnership program. Community partnerships came from businesses and corporations, faith organizations, or volunteers in the community. The partners primarily provided activities that were student-centered or school-centered. The activities that provided the greatest impact were student-centered activities that were focused on relationship building and promoting a greater understanding of life outside of the classroom. Advisor: Marilyn L. Grad

Comparison of Methods and Corn Root Types for Efficient Extraction of Endoparasitic Nematodes

Endoparasitic nematodes annually reduced the yield of corn in the United States. Pratylenchus spp. and Hoplolaimus spp. are endoparasitic nematode genera that parasitize corn in the Midwest. Previous research has shown nematode population densities to be highly variable and extraction methods may not provide consistent results. In order to determine more consistent and time efficient results, comparisons were made between four standard nematode extraction techniques for preferences of nematode genera for extraction method, corn root type, and extraction time. The extraction methods evaluated were aeration-incubation, a modified Baermann funnel, Seinhorst’s mister, and shaker incubation. Research plots were established at two Nebraska locations in 2009 and 2010 with documented histories of high population densities of these endoparasitic nematode genera. Nematodes were extracted from six root types on four extraction methods for 3, 5 and 7 days in a complete factorial treatment design. In 2009, Pratylenchus spp. were best extracted from the first set of anchor roots on the Baermann funnel (p \u3c 0.0001) or in the aerated incubation. Hoplolaimus spp. had the greatest recovery from seminal roots on the Baermann funnel in 2009 (p \u3c 0.0001). The mist extraction method did not have consistent results in 2009. For 2010, fine feeder roots in mist or aerated incubation had the greatest recovery of both genera of endoparasitic nematodes (p \u3c 0.0001). In most comparisons, 3-5 days of incubation was sufficient to extract at least 50% of the 7 day population density. For most root types, extraction timings, and nematode genera, the shaker method yielded the fewest nematodes per gram dried root (p \u3c 0.0001). Based on these results, it can be concluded that nematode extraction efficiency varies by genus for root type and extraction method. Advisor: Tamra A. Jackso

On Determining Minimal Spectrally Arbitrary Patterns

In this paper we present a new family of minimal spectrally arbitrary patterns which allow for arbitrary spectrum by using the Nilpotent-Jacobian method. The novel approach here is that we use the Intermediate Value Theorem to avoid finding an explicit nilpotent realization of the new minimal spectrally arbitrary patterns.Comment: 8 page

Phenomenology of ageing in the Kardar-Parisi-Zhang equation

We study ageing during surface growth processes described by the one-dimensional Kardar-Parisi-Zhang equation. Starting from a flat initial state, the systems undergo simple ageing in both correlators and linear responses and its dynamical scaling is characterised by the ageing exponents a=-1/3, b=-2/3, lambda_C=lambda_R=1 and z=3/2. The form of the autoresponse scaling function is well described by the recently constructed logarithmic extension of local scale-invariance.Comment: Latex2e, 5 pages, with 4 figures, final for

FCNC and CP Violation Observables in a SU(3)-flavoured MSSM

A non-Abelian flavour symmetry in a minimal supersymmetric standard model can explain the flavour structures in the Yukawa couplings and simultaneously solve the SUSY flavour problem. Similarly the SUSY CP problem can be solved if CP is spontaneously broken in the flavour sector. In this work, we present an explicit example of these statements with a SU(3) flavour symmetry and spontaneous CP violation. In addition, we show that it is still possible to find some significant deviation from the SM expectations as far as FCNC and CP violation are concerned. We find that large contributions can be expected in lepton flavour violating decays, as $\mu \to e \gamma$ and $\tau \to \mu \gamma$, electric dipole moments, $d_e$ and $d_n$ and kaon CP violating processes as $\epsilon_K$. Thus, these flavoured MSSM realizations are phenomenologically sensitive to the experimental searches in the realm of flavor and CP vioation physics.Comment: 56 pages, 12 figures; included new NLO contributions to nEDM from charged Higgs, relevant figures updated, and analysis of O(1) coefficients; added appendices and reference

Quantum chaos algorithms and dissipative decoherence with quantum trajectories

Using the methods of quantum trajectories we investigate the effects of dissipative decoherence in a quantum computer algorithm simulating dynamics in various regimes of quantum chaos including dynamical localization, quantum ergodic regime and quasi-integrable motion. As an example we use the quantum sawtooth algorithm which can be implemented in a polynomial number of quantum gates. It is shown that the fidelity of quantum computation decays exponentially with time and that the decay rate is proportional to the number of qubits, number of quantum gates and per gate dissipation rate induced by external decoherence. In the limit of strong dissipation the quantum algorithm generates a quantum attractor which may have complex or simple structure. We also compare the effects of dissipative decoherence with the effects of static imperfections.Comment: 6 pages, 6 figs, research at http://www.quantware.ups-tlse.f