Aquatic Macroinvertebrates of the White River National Wildlife Refuge, Arkansas

The objectives of this study were to survey the diversity of the aquatic macroinvertebrates ofthe White River National Wildlife Refuge (WRNWR) and determine relative abundances and distributional and seasonal patterns. No comprehensive investigation of WRNWR aquatic macroinvertebrates had been conducted previously. Thirty sampling stations were established within WRNWR. Each station was sampled twice, providing 60 totalsamples, for 1.5 man hours witha Turtox Indestructible™ dip net. Three black light trap samples were taken to augment the species list. A total of 15,056 individuials representing 219 taxa was taken by dip net samples during the sampling period October 1989-September 1990. Insects comprised 76% ofthe organisms captured withColeoptera being the dominant group. The most abundant organism for WRNWR was Hydroporus vitlalipennis. Black light samples and literature records each revealed 21 additional taxa bringing the total taxa currently known from WRNWR to 261. Each of the 30 stations was assigned to one of four associations, which were defined by continuity of determined internal and external factors. The Climax-Isolation Association possessed the most stable and complex community structures; isolation by levees and natural boundaries and scarcity of human intervention probably accounted for this. The Congruent Lentic Association embraced communal structures ofgood quality but possessed factors limiting diversity. The Agriculturally Inflicted-White River Tributary Association supported relaItivelysimple aquatic macroinvertebrate communities. Finally, the Restricted Association consisted oftwo stations containingsignificant limiting factors resulting in concomitantly depauperate aquatic macroinvertebrate communities

Evaluation of Ektachrome and Multiband Photography in Caliente Range, California

Ektachrome and multiband photography evaluation in Caliente Range of Californi

Maximizing phonon thermal conductance for ballistic membranes

At low temperatures, phonon scattering can become so weak that phonon transport becomes ballistic. We calculate the ballistic phonon conductance G for membranes using elasticity theory, considering the transition from three to two dimensions. We discuss the temperature and thickness dependence and especially concentrate on the issue of material parameters. For all membrane thicknesses, the best conductors have, counter-intuitively, the lowest speed of sound.Comment: 4 pages, 4 figures, proceedings to phonons 2007 conferenc

Elastic properties of cubic crystals: Every's versus Blackman's diagram

Blackman's diagram of two dimensionless ratios of elastic constants is frequently used to correlate elastic properties of cubic crystals with interatomic bondings. Every's diagram of a different set of two dimensionless variables was used by us for classification of various properties of such crystals. We compare these two ways of characterization of elastic properties of cubic materials and consider the description of various groups of materials, e.g. simple metals, oxides, and alkali halides. With exception of intermediate valent compounds, the correlation coefficients for Every's diagrams of various groups of materials are greater than for Blackaman's diagrams, revealing the existence of a linear relationship between two dimensionless Every's variables. Alignment of elements and compounds along lines of constant Poisson's ratio $\nu(,\textbf{m})$, ($\textbf{m}$ arbitrary perpendicular to ) is observed. Division of the stability region in Blackman's diagram into region of complete auxetics, auxetics and non-auxetics is introduced. Correlations of a scaling and an acoustic anisotropy parameter are considered.Comment: 8 pages, 9 figures, presented on The Ninth International School on Theoretical Physics "Symmetry and Structural Properties of Condensed Matter", 5 - 12 September 2007, Myczkowce, Polan

Vertex similarity in networks

We consider methods for quantifying the similarity of vertices in networks. We propose a measure of similarity based on the concept that two vertices are similar if their immediate neighbors in the network are themselves similar. This leads to a self-consistent matrix formulation of similarity that can be evaluated iteratively using only a knowledge of the adjacency matrix of the network. We test our similarity measure on computer-generated networks for which the expected results are known, and on a number of real-world networks

A Description of the Third Instar of Platambus flavovittaus (Larson and Wolfe, 1998) with Comments on the Larval Morphology of Platambus stagninus (Say, 1823) and a Key to the Agabini (Coleoptera: Dytiscidae) of Georgia

Mature Agabini larvae collected from a small temporary road-side habitat were reared to the adult stage and identified as Platambus flavovittattus (Larson and Wolfe, 1998). The mature larva is described and illustrated with an emphasis on leg morphology. Important differences between cranial temporal curvatures of P. flavovittatus and P. stagninus (Say, 1823) are described. A larval key is constructed to facilitate identification of Georgia agabine genera and species

Preliminary catalog of pictures taken on the lunar surface during the Apollo 15 mission

Catalog of all pictures taken from lunar module or lunar surface during Apollo 15 missio

The Cryogenic Refractive Indices of S-FTM16, a Unique Optical Glass for Near-Infrared Instruments

The Ohara glass S-FTM16 is of considerable interest for near-infrared optical designs because it transmits well through the K band and because negative S-FTM16 elements can be used to accurately achromatize positive calcium fluoride elements in refractive collimators and cameras. Glass manufacturers have sophisticated equipment to measure the refractive index at room temperature, but cannot typically measure the refractive index at cryogenic temperatures. Near-infrared optics, however, are operated at cryogenic temperatures to reduce thermal background. Thus we need to know the temperature dependence of S-FTM16's refractive index. We report here our measurements of the thermal dependence of S-FTM16's refractive index between room temperature and ~77 K. Within our measurement errors we find no evidence for a wavelength dependence or a nonlinear temperature term so our series of measurements can be reduced to a single number. We find that Delta n_{abs} / Delta T = -2.4x10^{-6} K^{-1} between 298 K and ~77 K and in the wavelength range 0.6 micron to 2.6 micron. We estimate that the systematic error (which dominates the measurement error) in our measurement is 10%, sufficiently low for most purposes. We also find the integrated linear thermal expansion of S-FTM16 between 298 K and 77 K is -0.00167 m m^{-1}.Comment: 8 pages, including 9 figures. Uses emulateapj.cls. Accepted for publication in PAS

Inflation-Produced Magnetic Fields in R^n F^2 and I F^2 models

We re-analyze the production of seed magnetic fields during Inflation in (R/m^2)^n F_{\mu \nu}F^{\mu \nu} and I F_{\mu \nu}F^{\mu \nu} models, where n is a positive integer, R the Ricci scalar, m a mass parameter, and I \propto \eta^\alpha a power-law function of the conformal time \eta, with \alpha a positive real number. If m is the electron mass, the produced fields are uninterestingly small for all n. Taking m as a free parameter we find that, for n \geq 2, the produced magnetic fields can be sufficiently strong in order to seed dynamo mechanism and then to explain galactic magnetism. For \alpha \gtrsim 2, there is always a window in the parameters defining Inflation such that the generated magnetic fields are astrophysically interesting. Moreover, if Inflation is (almost) de Sitter and the produced fields almost scale-invariant (\alpha \simeq 4), their intensity can be strong enough to directly explain the presence of microgauss galactic magnetic fields.Comment: 5 pages, 2 figures. Minor revisions. References added. Accepted for publication in Phys. Rev.