Illinois River Phosphorus Sampling Results and Mass Balance Computation

Phosphorus levels in the Illinois River are of great interest to the people of the States of Arkansas and Oklahoma. A great deal of effort has been expended to ascertain and modify the phosphorus impacts on the river. An automatic water sampling station was installed on the Illinois River just upstream from the State line in 1996 to accurately quantify the phosphorus in the Arkansas portion of the watershed. This paper summarizes five years worth of phosphorus sampling results at that site. In addition, a simple mass balance for phosphorus in the Illinois River Watershed above the sampling station was developed. The mass balance consisted of determining phosphorus inputs in the drainage area and comparing these to phosphorus outputs, during the same five-year period, allowing for an estimation of phosphorus accumulation. Sampling results showed that phosphorus levels were rapidly increasing in the Illinois River at the State line. Input information showed that over 7 million pounds of phosphorus were discharged into the 575 square mile basin annually. Mass balance calculations indicated that the point source discharges were responsible for up to 43% of the phosphorus in the river. The calculations indicate that only 4% of the phosphorus applied in the watershed reached the river annually. The remaining 96% accumulated in the watershed at an average rate of 8 kg per pasture acre per year. The effect of point source reductions was investigated and resulting mean concentrations were compared to a 0.037 mg/l in-stream phosphorus limit recently adopted by the State of Oklahoma

Simple Analyses of the Sparse Johnson-Lindenstrauss Transform

For every n-point subset X of Euclidean space and target distortion 1+eps for 0l_2^m where f(x) = Ax for A a matrix with m rows where (1) m = O((log n)/eps^2), and (2) each column of A is sparse, having only O(eps m) non-zero entries. Though the constructions given for such A in (Kane, Nelson, J. ACM 2014) are simple, the analyses are not, employing intricate combinatorial arguments. We here give two simple alternative proofs of their main result, involving no delicate combinatorics. One of these proofs has already been tested pedagogically, requiring slightly under forty minutes by the third author at a casual pace to cover all details in a blackboard course lecture

Information completeness in Nelson algebras of rough sets induced by quasiorders

In this paper, we give an algebraic completeness theorem for constructive logic with strong negation in terms of finite rough set-based Nelson algebras determined by quasiorders. We show how for a quasiorder $R$, its rough set-based Nelson algebra can be obtained by applying the well-known construction by Sendlewski. We prove that if the set of all $R$-closed elements, which may be viewed as the set of completely defined objects, is cofinal, then the rough set-based Nelson algebra determined by a quasiorder forms an effective lattice, that is, an algebraic model of the logic $E_0$, which is characterised by a modal operator grasping the notion of "to be classically valid". We present a necessary and sufficient condition under which a Nelson algebra is isomorphic to a rough set-based effective lattice determined by a quasiorder.Comment: 15 page

Toxic activity of organic extracts from Trichilia pallida Swartz (Meliaceae) against Spodoptera frugiperda (J. E. Smith)

The objective of this research was to evaluate the toxic activity of different concentrations (weight/volume) of organic extracts (non-aqueous) of leaves and twigs of Trichilia pallida Swartz on Spodoptera frugiperda (J. E. Smith) under laboratory conditions. Pieces of corn leaves were dipped in acetone solutions of T. pallida extracts at concentrations ranging from 0.008 to 1%. Larval mortality of S. frugiperda was evaluated during 10 days and acetone extracts of leaves and twigs and methanol extracts of twigs showed greater activity than methanol extract of leaves. Crude acetone extract was partitioned with hexane and ethyl acetate and evaluated by using the same methodology. Ethyl acetate fraction was more effective than hexane. Comparing the four solvents, the highest toxic activity of the extracts was obtained using acetone, followed by methanol, ethyl acetate and hexane.Avaliou-se, em condições de laboratório, o efeito de diferentes concentrações (peso/volume) de extratos orgânicos (não aquosos) de folhas e ramos de Trichilia pallida Swartz em relação à lagarta-do-cartucho Spodoptera frugiperda (J. E. Smith). Inicialmente, foram testados os extratos acetônico e metanólico nas concentrações de 0,008 a 1% impregnados em folhas de milho, constatando-se, com base na mortalidade larval até os 10 dias, que os extratos acetônicos de folhas e de ramos e o extrato metanólico de ramos apresentaram maior atividade que o extrato metanólico de folhas. Empregando a mesma metodologia, foram testados os extratos acetato de etila e hexânico obtidos pela partição do extrato acetônico bruto, constatando-se que o extrato acetato de etila foi mais efetivo que o hexânico. Comparando-se os quatro solventes, a maior atividade tóxica dos extratos foi obtida com a utilização de acetona, seguindo-se metanol, acetato de etila e hexano.79980

Virus shapes and buckling transitions in spherical shells

We show that the icosahedral packings of protein capsomeres proposed by Caspar and Klug for spherical viruses become unstable to faceting for sufficiently large virus size, in analogy with the buckling instability of disclinations in two-dimensional crystals. Our model, based on the nonlinear physics of thin elastic shells, produces excellent one parameter fits in real space to the full three-dimensional shape of large spherical viruses. The faceted shape depends only on the dimensionless Foppl-von Karman number \gamma=YR^2/\kappa, where Y is the two-dimensional Young's modulus of the protein shell, \kappa is its bending rigidity and R is the mean virus radius. The shape can be parameterized more quantitatively in terms of a spherical harmonic expansion. We also investigate elastic shell theory for extremely large \gamma, 10^3 < \gamma < 10^8, and find results applicable to icosahedral shapes of large vesicles studied with freeze fracture and electron microscopy.Comment: 11 pages, 12 figure

Macroscopic traffic models from microscopic car-following models

We present a method to derive macroscopic fluid-dynamic models from microscopic car-following models via a coarse-graining procedure. The method is first demonstrated for the optimal velocity model. The derived macroscopic model consists of a conservation equation and a momentum equation, and the latter contains a relaxation term, an anticipation term, and a diffusion term. Properties of the resulting macroscopic model are compared with those of the optimal velocity model through numerical simulations, and reasonable agreement is found although there are deviations in the quantitative level. The derivation is also extended to general car-following models.Comment: 12 pages, 4 figures; to appear in Phys. Rev.

Steady state solutions of hydrodynamic traffic models

We investigate steady state solutions of hydrodynamic traffic models in the absence of any intrinsic inhomogeneity on roads such as on-ramps. It is shown that typical hydrodynamic models possess seven different types of inhomogeneous steady state solutions. The seven solutions include those that have been reported previously only for microscopic models. The characteristic properties of wide jam such as moving velocity of its spatiotemporal pattern and/or out-flux from wide jam are shown to be uniquely determined and thus independent of initial conditions of dynamic evolution. Topological considerations suggest that all of the solutions should be common to a wide class of traffic models. The results are discussed in connection with the universality conjecture for traffic models. Also the prevalence of the limit-cycle solution in a recent study of a microscopic model is explained in this approach.Comment: 9 pages, 6 figure

Anisotropic Scaling in Threshold Critical Dynamics of Driven Directed Lines

The dynamical critical behavior of a single directed line driven in a random medium near the depinning threshold is studied both analytically (by renormalization group) and numerically, in the context of a Flux Line in a Type-II superconductor with a bulk current $\vec J$. In the absence of transverse fluctuations, the system reduces to recently studied models of interface depinning. In most cases, the presence of transverse fluctuations are found not to influence the critical exponents that describe longitudinal correlations. For a manifold with $d=4-\epsilon$ internal dimensions, longitudinal fluctuations in an isotropic medium are described by a roughness exponent $\zeta_\parallel=\epsilon/3$ to all orders in $\epsilon$, and a dynamical exponent $z_\parallel=2-2\epsilon/9+O(\epsilon^2)$. Transverse fluctuations have a distinct and smaller roughness exponent $\zeta_\perp=\zeta_\parallel-d/2$ for an isotropic medium. Furthermore, their relaxation is much slower, characterized by a dynamical exponent $z_\perp=z_\parallel+1/\nu$, where $\nu=1/(2-\zeta_\parallel)$ is the correlation length exponent. The predicted exponents agree well with numerical results for a flux line in three dimensions. As in the case of interface depinning models, anisotropy leads to additional universality classes. A nonzero Hall angle, which has no analogue in the interface models, also affects the critical behavior.Comment: 26 pages, 8 Postscript figures packed together with RevTeX 3.0 manuscript using uufiles, uses multicol.sty and epsf.sty, e-mail [email protected] in case of problem