Remote sensing and geographic information systems for decision analysis in public resource administration: Case study in a Southwestern watershed

Alternative futures analysis is a scenario-based approach to regional land planning that attempts to synthesize existing scientific information in a format useful to community decision makers. Typically, this approach attempts to investigate the impacts of several alternative sets of choices preferred by representative stakeholder groups relative to selected environmental or economical endpoints. Potential impacts from each of the scenarios are compared to current conditions of the region in terms of a set of processes that are modeled within a geographic information system. Future conditions are generally examined from the perspective of a recent baseline condition (versus empirically determined using a series of retrospective measurements). During the past two decades, important advances in the integration of remote imagery, computer processing, and spatial analysis technologies have been linked to the study of distribution patterns of communities and ecosystems and the ecological processes that affect these patterns. Because of the 25+ year availability of commercial satellite imagery, it is possible to examine environmental change and establish models which can narrow the actual choice of possible and probable change scenarios. This professional paper examines the potential to establish reference condition and measure change over large geographic areas; determine trends in environmental condition; and model and predict future landscape scenarios using advanced space-based technologies. Specifically, landscape pattern measurements were developed from satellite remote sensing, spatial statistics, and geographic information systems technology for a semi-arid watershed in southeast Arizona and northeast Sonora, Mexico and evaluated for their use in a decision-making framework

Reproductive Biology of Longfin Dace (Agosia chrysogaster) in a Sonoran Desert Stream, Arizona

original available only as paper hard copy from Arizona State University at time of publication here.The longfin dace, Agosia chrysogaster Girard, is the most abundant native minnow of low elevation (< 1,500 m) streams in Arizona, parts of southwestern New Mexico, and northern Mexico. Reproductive life history of longfin dace was examined over a 12-month period (1977-78) in Aravaipa Creek, Graham and Pinal counties, Arizona. Adult males and females are sexually dimorphic, clearly distinguishable by differences in size of fins. Gravid females and tuberculate males persisted throughout the year and spawned in shallow saucer-shaped depressions in sand-bottomed backwaters and runs. Although individual spawning activity was asynchronous, populations reached peak spawning condition at least twice within the year. Peak reproductive activity was during increased discharge in spring and late summer. Fecundity was primarily a function of size. Ovary weight was highly correlated with fecundity and was the most reliable indicator of total mature ova produced.Integrative Biolog

A Parallel Solver for Graph Laplacians

Problems from graph drawing, spectral clustering, network flow and graph partitioning can all be expressed in terms of graph Laplacian matrices. There are a variety of practical approaches to solving these problems in serial. However, as problem sizes increase and single core speeds stagnate, parallelism is essential to solve such problems quickly. We present an unsmoothed aggregation multigrid method for solving graph Laplacians in a distributed memory setting. We introduce new parallel aggregation and low degree elimination algorithms targeted specifically at irregular degree graphs. These algorithms are expressed in terms of sparse matrix-vector products using generalized sum and product operations. This formulation is amenable to linear algebra using arbitrary distributions and allows us to operate on a 2D sparse matrix distribution, which is necessary for parallel scalability. Our solver outperforms the natural parallel extension of the current state of the art in an algorithmic comparison. We demonstrate scalability to 576 processes and graphs with up to 1.7 billion edges.Comment: PASC '18, Code: https://github.com/ligmg/ligm

Production of linalool, cis- and trans-nerolidol, and trans,trans-farnesol by Saccharomyces fermentati growing as a film on simulated wine

Linalool, cis-nerolidol, trans-nerolidol, and trans,trans-farnesol are produced in low concentrations by the wine yeast Saccharomyces fermentati growing as a film for 10 weeks on the surface of a simulated fino sherry containing ethanol as the only volatile carbon containing compound. lt is not known whether Saccharomyces cerevisiae also produces terpenes while fermenting grape juice to wine. However, caution seems advisable in differentiating among Vitis vinifera cultivars on the basis of terpenes found in the wines.Die Bildung von Linalool, cis- und trans-Nerolidol sowie trans,trans-Farnesol durch eine Decke von Saccharomyces fermentati auf einem ModellweinDie deckenbildende Form von Saccharomyces fermentati erzeugte im Verlauf von 10 Wochen auf einem simulierten Fino-Sherry, der als einzige flüchtige Kohlenstoffverbindung Äthanol enthielt, geringe Mengen von Linalool, cis-Nerolidol, trans-Nerolidol und trans,trans-Farnesol. Es ist zwar nicht bekannt, ob Saccharomyces cerevisiae bei der Vergärung von Traubensaft ebenfalls Terpene bildet; trotzdem scheint Vorsicht geboten zu sein, wenn Vitis-vinifera-Sorten aufgrund der in den Weinen gefundenen Terpene charakterisiert werden

Model for Gravitational Interaction between Dark Matter and Baryons

We propose a phenomenological model where the gravitational interaction between dark matter and baryons is suppressed on small, subgalactic scales. We describe the gravitational force by adding a Yukawa contribution to the standard Newtonian potential and show that this interaction scheme is effectively suggested by the available observations of the inner rotation curves of small mass galaxies. Besides helping in interpreting the cuspy profile of dark matter halos observed in N-body simulations, this potential regulates the quantity of baryons within halos of different masses.Comment: 4 pages, 2 figures, final versio

Highly-Ionized High-Velocity Gas in the Vicinity of the Galaxy

We report the results of an extensive FUSE study of high velocity OVI absorption along 102 complete sight lines through the Galactic halo. The high velocity OVI traces a variety of phenomena, including tidal interactions with the Magellanic Clouds, accretion of gas, outflow from the Galactic disk, warm/hot gas interactions in a highly extended Galactic corona, and intergalactic gas in the Local Group. We identify 85 high velocity OVI features at velocities of -500 < v(LSR) < +500 km/s along 59 of the 102 sight lines. Approximately 60% of the sky (and perhaps as much as 85%) is covered by high velocity H+ associated with the high velocity OVI. Some of the OVI is associated with known high velocity HI structures (e.g., the Magellanic Stream, Complexes A and C), while some OVI features have no counterpart in HI 21cm emission. The smaller dispersion in the OVI velocities in the GSR and LGSR reference frames compared to the LSR is necessary (but not conclusive) evidence that some of the clouds are extragalactic. Most of the OVI cannot be produced by photoionization, even if the gas is irradiated by extragalactic background radiation. Collisions in hot gas are the primary OVI ionization mechanism. We favor production of some of the OVI at the boundaries between warm clouds and a highly extended [R > 70 kpc], hot [T > 10^6 K], low-density [n < 10^-4 cm^-3] Galactic corona or Local Group medium. A hot Galactic corona or Local Group medium and the prevalence of high velocity OVI are consistent with predictions of galaxy formation scenarios. Distinguishing between the various phenomena producing high velocity OVI will require continuing studies of the distances, kinematics, elemental abundances, and physical states of the different types of high velocity OVI features found in this study. (abbreviated)Comment: 78 pages of text/tables + 31 figures, AASTeX preprint format. All figures are in PNG format due to astro-ph space restrictions. Bound copies of manuscript and two accompanying articles are available upon request. Submitted to ApJ

Photometric validation of a model independent procedure to extract galaxy clusters

By means of CCD photometry in three bands (Gunn g, r, i) we investigate the existence of 12 candidate clusters extracted via a model independent peak finding algorithm (\cite{memsait}) from DPOSS data. The derived color-magnitude diagrams allow us to confirm the physical nature of 9 of the cluster candidates, and to estimate their photometric redshifts. Of the other candidates, one is a fortuitous detection of a true cluster at z~0.4, one is a false detection and the last is undecidable on the basis of the available data. The accuracy of the photometric redshifts is tested on an additional sample of 8 clusters with known spectroscopic redshifts. Photometric redshifts turn out to be accurate within z~0.01 (interquartile range).Comment: A&A in pres

The Delayed Formation of Dwarf Galaxies

One of the largest uncertainties in understanding the effect of a background UV field on galaxy formation is the intensity and evolution of the radiation field with redshift. This work attempts to shed light on this issue by computing the quasi-hydrostatic equilibrium states of gas in spherically symmetric dark matter halos (roughly corresponding to dwarf galaxies) as a function of the amplitude of the background UV field. We integrate the full equations of radiative transfer, heating, cooling and non-equilibrium chemistry for nine species: H, H^+, H^-,H_2, H_2^+, He, He^+, He^{++}, and e^-. As the amplitude of the UV background is decreased the gas in the core of the dwarf goes through three stages characterized by the predominance of ionized (H^+), neutral (H) and molecular (H_2) hydrogen. Characterizing the gas state of a dwarf galaxy with the radiation field allows us to estimate its behavior for a variety of models of the background UV flux. Our results indicate that a typical radiation field can easily delay the collapse of gas in halos corresponding to 1-$\sigma$ CDM perturbations with circular velocities less than 30 km/s.Comment: 23 pages (including 8 figures). Figures 3 and 8 best viewed in colo

The tidal tails of NGC 2298

We present an implementation of the matched-filter technique to detect tidal tails of globular clusters. The method was tested using SDSS data for the globular cluster Palomar 5 revealing its well known tidal tails. We also ran a simulation of a globular cluster with a tidal tail where we successfully recover the tails for a cluster at the same position and with the same characteristics of NGC 2298. Based on the simulation we estimate that the matched-filter increases the contrast of the tail relative to the background of stars by a factor of 2.5 for the case of NGC 2298. We also present the photometry of the globular cluster NGC 2298 using the MOSAIC2 camera installed on the CTIO 4m telescope. The photometry covers ~ 3deg2 reaching V ~ 23. A fit of a King profile to the radial density profile of NGC 2298 shows that this cluster has a tidal radius of 15.91' \pm 1.07' which is twice as in the literature. The application of the matched-filter to NGC 2298 reveals several extra-tidal structures, including a leading and trailing tail. We also find that NGC 2298 has extra-tidal structures stretching towards and against the Galactic disk, suggesting strong tidal interaction. Finally, we assess how the matched-filter performs when applied to a globular cluster with and without mass segregation taken into account. We find that disregarding the effects of mass segregation may significantly reduce the detection limit of the matched-filter.Comment: 11 pages, 9 figures, 1 table. Accepted for publication on MNRAS main journa