Search

Wildfires burned 24,254?ha of critical habitat designated for the recovery of the threatened Mojave desert tortoise (Gopherus agassizii) in southern Nevada during 2005. The proliferation of non-native annual grasses has increased wildfire frequency and extent in recent decades and continues to accelerate the conversion of tortoise habitat across the Mojave Desert. Immediate changes to vegetation are expected to reduce quality of critical habitat, yet whether tortoises will use burned and recovering habitat differently from intact unburned habitat is unknown. We compared movement patterns, home-range size, behavior, microhabitat use, reproduction, and survival for adult desert tortoises located in, and adjacent to, burned habitat to understand how tortoises respond to recovering burned habitat. Approximately 45% of home ranges in the post-fire environment contained burned habitat, and numerous observations (n?=?12,223) corroborated tortoise use of both habitat types (52% unburned, 48% burned). Tortoises moved progressively deeper into burned habitat during the first 5 years following the fire, frequently foraging in burned habitats that had abundant annual plants, and returning to adjacent unburned habitat for cover provided by intact perennial vegetation. However, by years 6 and 7, the live cover of the short-lived herbaceous perennial desert globemallow (Sphaeralcea ambigua) that typically re-colonizes burned areas declined, resulting in a contraction of tortoise movements from the burned areas. Health and egg production were similar between burned and unburned areas indicating that tortoises were able to acquire necessary resources using both areas. This study documents that adult Mojave desert tortoises continue to use habitat burned once by wildfire. Thus, continued management of this burned habitat may contribute toward the recovery of the species in the face of many sources of habitat loss. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

The article discusses a study which investigated a correlation between the proportion of range cover and proportion of canopy cover with plumage damage of end-of-lay hens. Specifically, the study is aimed at improving range environment and welfare of laying hens or Gallus gallus domesticus within the British supply base of McDonald's Restaurants Ltd. through a collaboration with two egg-producing companies. It was revealed that there were correlations between plumage damage score, mortality and canopy cover within planted areas.

AbstractPerformance metrics and evaluation criteria are used to develop a novel taxonomy that classifies barrier mechanisms into categories ranging from simple Static-Binding Idle-Tasking methods to robust Dynamic-Binding Any-Tasking methods. Such capabilities include support for multiple barriers, reconfigurable and reusable synchronization resources, and provisions for dynamic process binding. Based on these features, the existing software-based approaches, dedicated-hardware mechanisms, and hybrid hardware/software techniques for synchronization are assessed in order of increasing complexity. Any barrier synchronization algorithm can be readily classified using this taxonomy to understand resource requirements and performance tradeoffs.

The X-ray absorption near edge structure XANES at the calcium K-edge is rich in information, but complex and difficult to interpret fully. We present here a systematic study of a range of calciumoxygen containing compounds and minerals and show that the XANES may be used to obtain qualitative information on the calcium coordination environment.

Recently an approach for multi-model identification and failure detection in the presence of bounded energy noise over short time intervals has been introduced. In this paper it is shown how this approach can be extended to some problems with delays. Computational issues are carefully addressed and an example is worked.

Abstract: The wave surface profiles associated with extreme relative motion between a slender stationary vessel and the adjacent wave surface are investigated for long-crested head seas. The methodology is based upon an established statistical relationship for a Gaussian random process which indi-cates that in the vicinity of an extreme event the most probable shape of the time history approaches that of the autocorrelation function. Attention is given to the relative motion at a longitudinal position which is representative of the No. 1 hatch cover location on a bulk carrier. Second-order corrections to the wave surface profiles are used to provide estimates of nonlinear relative motions. It is shown that extreme relative motion at the hatch cover location is associated with the vessel encountering a steep-fronted wave with pronounced asymmetry in the horizontal and vertical directions. In order to evaluate the exceedence probabilities, it is hypothesized that the peaks of the nonlinear relative motions are closely correlated with the peaks of an underlying linear process. The overall methodology is applied to an investigation of relative motion exceedence probabilities for vessel lengths of 250 m and 300 m over a range of survival seastates.

Experimental results are presented that support theory published in the literature concerning the use of a navigation line for the guidance of mobile robots. A method for the determination of a robot's position is developed. A specialized edge operator, which aids in the segmentation of a navigation line from an image of a robot's environment, is given. Use of this specialized edge operator in conjunction with the Hough transform is also presented. These methods are used to verify the analytical results given previously. Comparisons are made between experimental data and expected results as a function of various system parameters. Real-time implementation of these methods is considered.

In previous studies of the structures of bimetallic clusters using extended X-ray absorption fine structure (EXAFS), structural parameters were determined by fitting the single scattering expression for EXAFS to experimental data associated with an absorption edge of each component. The data for the two edges were fitted separately. Recently, with an extensive modification of the computer program for the analysis of EXAFS data, it has been possible to fit the EXAFS data for the two edges simultaneously. This improved method of analysis has the feature thatall of the EXAFS data are used in the determination ofall of the structural parameters, and permits one to impose in a direct manner certain necessary physical conditions regarding the system. Consequently, one has greater confidence in the values obtained for the parameters. The present paper first summarizes published results obtained by the previous method of analysis on a number of systems. For comparison, a summary is then given of results obtained from the same data on these systems with the new method of analysis.

Two European projects-the Euroworkstation and Spirit-aimed at producing the next generation of multiprocessor, high-performance, extensible workstations are discussed. The goal is to compete with US products currently dominating the market. The two projects also aim to satisfy various levels of graphics performance: flight simulators that render scenes at interactive rates, various forms of animation, and high-quality, static scene rendering. The architecture, hardware and software of each approach are examined.<>

Depressed hay prices in 1987 prompted Wyoming hay producer organizations to request marketing assistance from the Wyoming Cooperative Extension Service (WCES) and the Wyoming Department of Agriculture (WDA). The WCES and the WDA responded by implementing a 2-yr project to analyze and promote quality hay (WYOLIST). Hay quality and marketing improved with fee-based evaluation consisting of a standardized visual appraisal and chemical analysis. Quality of evaluated hay improved significantly from the first to second marketing seasons. However, sharply higher prices for hay, due to diminished supply and increased demand during the second season, reduced grower participation in hay evaluation. Nevertheless, cash premiums were documented for some sale lots of higher quality hay during both marketing seasons.

A methodology for conducting competitive exhibitions or hay contests was developed to evaluate, teach, and promote hay quality. Exhibits are subjected to a forage analysis and a visual appraisal for economically important variables. The criteria for visual appraisal are particularly appropriate for hay produced and marketed in the Wyoming environment. This model is a standardized, rigorous, yet flexible approach used to coordinate county and state fair events in Wyoming.

Competitive exhibitions or hay contests of commercially produced alfalfa (Medicago sativaL.) hay were conducted for 3 yr at county and state fairs to foster awareness of modern concepts of forage analysis and visual appraisal. Participants were rewarded for exhibiting prime quality hay, the highest standard designated by the Hay Marketing Task Force of the American Forage and Grassland Council. Participants demonstrated an improved awareness of factors associated with prime quality hay by increasing the average quality of exhibits. Average crude protein (CP) improved by 22 and 21% for groups designated as previous and first-time participants, respectively. Average relative feed value (RFV) improved by 72 and 48%, respectively, for the same groups. Most improvement in multiple-event groups occurred by the second year of participation. First-time participant groups also improved during the 3-yr period, but at a slower rate. Average scores for previous-event participants exceeded quality standards for prime for both CP and RFV by Year 2. Average scores for first-time participant groups exceeded minimum standards for prime quality hay by Year 2 for RFV and by Year 3 for CP. Results suggest that individuals who had previously participated in competitive exhibitions learned more rapidly and achieved a consistently higher level of hay quality than did individuals participating for the first time.

Escherichia coli strains which produce heat-stable enterotoxin (ST) are usually identified by demonstrating the production of ST. At present, ST can be detected only by bioassay methods. Recently, we purified E. coli ST, which enabled us to develop a radioimmunoassay for ST. Radioiodination of ST was performed by the lactoperoxidase method, which resulted in a high specific activity and retained the biological activity of St. Anti-ST antisera were raised in goats by injecting the goats with pure ST coupled to bovine immunoglobin G. Antibody titers ranged from 1:8,000 to 1:40,000. Using these reagents, we examined assay conditions thoroughly and found that a 14- to 18-h incubation at 4 degrees C in sodium acetate buffer with an ionic strength of 120 mM (pH 6.2) gave maximal sensitivity and reproducibility. Free ST was separated from antibody-bound ST by dextran-coated charcoal. This radioimmunoassay accurately and reproducibly measured ST in the range from 50 to 500 pg of ST per tube and could quantitate ST accurately in complex bacteriological media. This assay was specific for STa, measured human and porcine STa equally well, and did not cross-react with STb, with several other enterotoxins, or with various gastrointestinal peptides. Intact disulfide bridges in the ST molecule were required for immunoreactive activity.

A novel technique for ultrahigh-resolution laser spectroscopy is described. Coherence between atomic substates created by an amplitude-modulated light beam is monitored in transmission of a weak probe beam by polarization-selective optical heterodyne detection. As a demonstration, the technique is applied to Zeeman sublevels of the sodium ground state. The width (FWHM) of the observed resonances corresponds to 60 kHz.

This bibliography includes publications which have come to notice from December, 1946-February, 1947, and has been prepared in collaboration with Miss R. Fones (International African Institute). M. C. Laroche (Mimstere de la France d'utre-Mer) and Professor T. Heyse (Belgian Ministry of Colonies) have kindly supplied information regarding French and Belgian publications.

This bibliography includes publications which have come to notice from March to May 1947. M. C. Laroche (Ministere de la France d'Outre-Mer) and Professor T. Heyse (Belgian Ministry of Colonies) have kindly supplied information.

This bibliography includes publications which have come to notice from September-November 1946 and has been prepared in collaboration with Professor T. Heyse (Belgian Ministry of Colonies), Miss R. Jones (International African Institute), Professor E. Ruffini (Italian Embassy, London), and Miss M. Sinclair (International Review of Missions).