Isolation of a Novel Phage OTooleKemple52

A bacteriophage is a virus capable of infecting bacteria like ubiquitous soil-dwelling genus Bacillus. Within the Bacillus genus, there is the “ACT family” made up of B. thuringiensis, B. cereus, and B. anthracis, which are highly related but with different pathogenic characteristics. Because of this, phages isolated using a species in this group may have a broad host range encompassing several species from Bacillus. Since B. cereus and B. anthracis can result in fatal to mild sickness in humans, the non-pahtogenic B. thuringiensis kurstaki was used to discover and characterize novel phages. The phage OTooleKemple52 was isolated from a soil sample collected from Chesapeake, VA using “soil enrichment” to increase phage concentration and thus make detection more likely. A phage plaque was observed from this enrichment infection upon plating. The phage population was then purified until the morphology of the phage plaques was consistent (3 mm diameter with pinpoint clear centers). A large volume of phage stock (high titer lysate, HTL) was collected and was then used to obtain purified DNA for gel electrophoresis and genome sequencing. Additionally, an HTL sample was stained with 1% uranyl acetate and imaged using transmission electron microscopy to determine a myoviridae morphology with a head diameter of 80 nm and a tail length of 200 nm. The phage has a broad host range and was able to able to form plaques on 6 out of 8 Bacillus strains tested. The genome of the phage will be annotated and compared to other phage genomes. Through studying phages we can work to better understand both phage diversity and the interrelatedness of the Bacillus genus. The benefits of studying bacteriophages have reaches from environmental to medical significance because of the ubiquitous and pathogenic characteristics of the host bacteria.https://scholarscompass.vcu.edu/uresposters/1241/thumbnail.jp

Hydrodynamics of Monolayer Domains at the Air-Water Interface

Molecules at the air-water interface often form inhomogeneous layers in which domains of different densities are separated by sharp interfaces. Complex interfacial pattern formation may occur through the competition of short- and long-range forces acting within the monolayer. The overdamped hydrodynamics of such interfacial motion is treated here in a general manner that accounts for dissipation both within the monolayer and in the subfluid. Previous results on the linear stability of interfaces are recovered and extended, and a formulation applicable to the nonlinear regime is developed. A simplified dynamical law valid when dissipation in the monolayer itself is negligible is also proposed. Throughout the analysis, special attention is paid to the dependence of the dynamical behavior on a characteristic length scale set by the ratio of the viscosities in the monolayer and in the subphase.Comment: 12 pages, RevTeX, 4 ps figures, accepted in Physics of Fluids

Composite CDMA - A statistical mechanics analysis

Code Division Multiple Access (CDMA) in which the spreading code assignment to users contains a random element has recently become a cornerstone of CDMA research. The random element in the construction is particular attractive as it provides robustness and flexibility in utilising multi-access channels, whilst not making significant sacrifices in terms of transmission power. Random codes are generated from some ensemble, here we consider the possibility of combining two standard paradigms, sparsely and densely spread codes, in a single composite code ensemble. The composite code analysis includes a replica symmetric calculation of performance in the large system limit, and investigation of finite systems through a composite belief propagation algorithm. A variety of codes are examined with a focus on the high multi-access interference regime. In both the large size limit and finite systems we demonstrate scenarios in which the composite code has typical performance exceeding sparse and dense codes at equivalent signal to noise ratio.Comment: 23 pages, 11 figures, Sigma Phi 2008 conference submission - submitted to J.Stat.Mec

Waiting For The Moon And You

https://digitalcommons.library.umaine.edu/mmb-vp/5059/thumbnail.jp

Modeling Non-Linear Spatial Dynamics: A Family of Spatial STAR Models and an Application to U.S. Economic Growth

This paper investigates non-linearity in spatial processes models and allows for a gradual regime-switching structure in the form of a smooth transition autoregressive process. Until now, applications of the smooth transition autoregressive (STAR) model have been largely confined to the time series context. The paper focuses on extending the non-linear smooth transition perspective to spatial processes models, in which spatial correlation is taken into account through the use of a so-called weights matrix identifying the topology of the spatial system. We start by deriving a non-linearity test for a simple spatial model, in which spatial correlation is only included in the transition function. Next, we propose a non-linearity test for a model that includes a spatially lagged dependent variable or spatially autocorrelated innovations as well. Monte Carlo simulations of the various test statistics are performed to examine their power and size. The proposed modeling framework is then used to identify convergence clubs in the context of U.S. county-level economic growth over the period 1963–2003.spatial econometrics, non-linearity, utoregressive smooth transition, Research Methods/ Statistical Methods, C12, C21, C51, O18, R11,

Employment Growth and Income Inequality: Accounting for Spatial and Sectoral Differences

This paper revisits the inequality-growth relationship accounting for sectoral differences and focusing on US counties. For 8 two-digit industries of the NAICS classification, we estimated a conditional growth model where employment growth depends on regional income inequality and a number of control variables. Spatial econometrics techniques are used to account for spatial dependence. Results indicate that there is no association between employment growth and family income inequality for the Agriculture, Forestry, Fishing and Hunting sector and the Real Estate, Rental and Leasing sector. However, income inequality consistently shows a negative impact on employment growth in the construction sector, and results are mixed for other sectors such as: Manufacturing; Retail Trade; Professional Scientific and Technical Services; Accommodation and Food Services; Educational Services. In several sectors, mixed results were obtained when differentiation is made between urban and rural samples.employment growth, inequality, spatial dependence, Community/Rural/Urban Development, R0, R11, O15, D30,