Issues with scale using very high resolution digital aerial photographs

Abstract only availableThis study involves the use of remote sensing equipment to observe plant communities. A remote sensor is any instrument that gathers information about an object or area from a distance. Advanced cameras, the most common sensors used in aerial study, take photographs capable of revealing objects (vegetation, trees, etc...) only a few millimeters or inches in width from altitudes of 10 to 150 meters. The objective of the projective is to determine the resolution to acquire the photographs. In this study, existing and current images are used to classify the vegetation into the classes as needed. The main goal is to classify the images based on the known targets. Images are taken primarily from helium balloons that have a digital attached to capture the image of the intended area of study. The tools used in this project are ERDAS Imagine 8.6 and ArcGIS for image processing and classifying the images into classes using colors and characteristics of the area and surroundings.Louis Stokes Missouri Alliance for Minority Participatio

Liposomes modulate human immunodeficiency virus infectivity

We have investigated the effects of the fusion of liposomes with human immunodeficiency virus type 1 (HIV-1(LVA)) on the ability of the virus to infect CD4+ and CD4- cells. Fluorescence dequenching measurements indicated that HIV-1 fuses with liposomes composed of either cardiolipin (CL) or N-[2,3-(dioleyloxy) propyl]-N,N,N-trimethyl ammonium chloride (DOTMA) but not appreciably with dioleoylphosphatidylcholine (DOPC) liposomes. Pre-incubation of HIV-1 with DOTMA liposomes enhanced virus production (measured by p24 gag antigen production in the culture medium and in situ) in CD4+ A3.01 and H9 cells in a concentration-dependent manner, but did not mediate the infection of the CD4- cell line, K562. Preincubation of HIV-1 with between 10 and 30 μM-DOTMA liposomes, and subsequent incubation with A3.01 cells, resulted in the production of about 30-fold greater levels of virus than controls. The presence of DOTMA liposomes during the incubation of A3.01 cells with HIV-1 enhanced the infectivity of the virus up to 90-fold compared to controls. Conversely, preincubation of HIV-1 with CL liposomes inhibited infection of A3.01 cells, dependent on the concentration of liposomes; DOPC liposomes did not alter the infectivity of the virus under any of the incubation conditions. Our results thus indicate that fusion of HIV-1 with liposomes alters the ability of the virus to infect its target cells

The Chemical Properties of Milky Way and M31 Globular Clusters: I. A Comparative Study

A comparative analysis is performed between high-quality integrated spectra of 30 globular clusters in M31, 20 Milky Way clusters, and a sample of field and cluster elliptical galaxies. We find that the Lick CN indices in the M31 and Galactic clusters are enhanced relative to the bulges of the Milky Way, M31, and elliptical spheroids. Although not seen in the Lick CN indices, the near-UV cyanogen feature (3883 A) is strongly enhanced in M31 clustesr with respect to the Galactic globulars at metallicities, --1.5<[Fe/H]<--0.3. Carbon shows signs of varying amongst these two groups. For [Fe/H]>--0.8, we observe no siginificant differences in the Hdelta, Hgamma, or Hbeta indices between the M31 and Galactic globulars. The sample of ellipticals lies offset from the loci of all the globulars in the Cyanogen--[MgFe], and Balmer--[MgFe] planes. Six of the M31 cluster spectra appear young, and are projected onto the M31 disk. Population synthesis models suggest that these are metal-rich clusters with ages 100--800 Myr, metallicities --0.20 < [Fe/H] <0.35, and masses 0.7 -7.0x10^4 Msun. Two other young clusters are Hubble V in NGC 205, and an older (~3 Gyr) cluster ~7 kpc away from the plane of the disk. The six clusters projected onto the disk rotate in a similar fashion to the HI gas in M31, and three clusters exhibit thin disk kinematics (Morrison et al.). Dynamical masses and structural parameters are required for these objects to determine whether they are massive open clusters or globular clusters. If the latter, our findings suggest globular clusters may trace the build up of galaxy disks. In either case, we conclude that these clusters are part of a young, metal-rich disk cluster system in M31, possibly as young as 1 Gyr old.Comment: 52 pages, 14 figures, 8 tables, minor revisions in response to referee, conclusions remain the same. Scheduled to appear in the October 2004 issue of The Astronomical Journa

String Junctions and Bound States of Intersecting Branes

We study four-dimensional black hole configurations which result from wrapping M5-branes on a Calabi-Yau manifold, as well as U-dual realizations. Our aim is to understand the microscopic degrees of freedom responsible for the existence of bound states of multiple branes. The details depend on the chosen U-frame; in some cases, they are massless string junctions. We also identify a perturbative description in which these states correspond to twisted strings of intersecting D3-branes at an orbifold singularity. In each case, these are the preponderant states of the spacetime infrared conformal field theory and account for the entropy of the blackhole.Comment: 14 pages; 2 figures; uses latex with epsf and hyperref package

Exploring Halo Substructure with Giant Stars IV: The Extended Structure of the Ursa Minor Dwarf Spheroidal

We present a large area photometric survey of the Ursa Minor dSph. We identify UMi giant star candidates extending to ~3 deg from the center of the dSph. Comparison to previous catalogues of stars within the tidal radius of UMi suggests that our photometric luminosity classification is 100% accurate. Over a large fraction of the survey area, blue horizontal branch stars associated with UMi can also be identified. The spatial distribution of both the UMi giant stars and the BHB stars are remarkably similar, and a large fraction of both samples of stars are found outside the tidal radius of UMi. An isodensity contour map of the stars within the tidal radius of UMi reveals two morphological peculiarities: (1) The highest density of dSph stars is offset from the center of symmetry of the outer isodensity contours. (2) The overall shape of the outer contours appear S-shaped. We find that previously determined King profiles with ~50' tidal radii do not fit well the distribution of our UMi stars. A King profile with a larger tidal radius produces a reasonable fit, however a power law with index -3 provides a better fit for radii > 20'. The existence of UMi stars at large distances from the core of the galaxy, the peculiar morphology of the dSph within its tidal radius, and the shape of its surface density profile all suggest that UMi is evolving significantly due to the tidal influence of the Milky Way. However, the photometric data on UMi stars alone does not allow us to determine if the candidate extratidal stars are now unbound or if they remain bound to the dSph within an extended dark matter halo. (Abridged)Comment: accepted by AJ, 32 pages, 15 figures, emulateapj5 styl

Kinematics of Metal-Poor Stars in the Galaxy. II. Proper Motions for a Large Non-Kinematically Selected Sample

We present a revised catalog of 2106 Galactic stars, selected without kinematic bias, and with available radial velocities, distance estimates, and metal abundances in the range 0.0 <= [Fe/H] <= -4.0. This update of the Beers and Sommer-Larsen (1995) catalog includes newly-derived homogeneous photometric distance estimates, revised radial velocities for a number of stars with recently obtained high-resolution spectra, and refined metallicities for stars originally identified in the HK objective-prism survey (which account for nearly half of the catalog) based on a recent re-calibration. A subset of 1258 stars in this catalog have available proper motions, based on measurements obtained with the Hipparcos astrometry satellite, or taken from the updated Astrographic Catalogue (AC 2000; second epoch positions from either the Hubble Space Telescope Guide Star Catalog or the Tycho Catalogue), the Yale/San Juan Southern Proper Motion (SPM) Catalog 2.0, and the Lick Northern Proper Motion (NPM1) Catalog. Our present catalog includes 388 RR Lyrae variables (182 of which are newly added), 38 variables of other types, and 1680 non-variables, with distances in the range 0.1 to 40 kpc.Comment: 31 pages, including 8 figures, to appear in AJ (June 2000), full paper with all figures embedded available at http://pluto.mtk.nao.ac.jp/people/chiba/preprint/halo4

Using schedulers to test probabilistic distributed systems

This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s00165-012-0244-5. Copyright © 2012, British Computer Society.Formal methods are one of the most important approaches to increasing the confidence in the correctness of software systems. A formal specification can be used as an oracle in testing since one can determine whether an observed behaviour is allowed by the specification. This is an important feature of formal testing: behaviours of the system observed in testing are compared with the specification and ideally this comparison is automated. In this paper we study a formal testing framework to deal with systems that interact with their environment at physically distributed interfaces, called ports, and where choices between different possibilities are probabilistically quantified. Building on previous work, we introduce two families of schedulers to resolve nondeterministic choices among different actions of the system. The first type of schedulers, which we call global schedulers, resolves nondeterministic choices by representing the environment as a single global scheduler. The second type, which we call localised schedulers, models the environment as a set of schedulers with there being one scheduler for each port. We formally define the application of schedulers to systems and provide and study different implementation relations in this setting