Globular Clusters in the Sombrero Galaxy (NGC 4594)

The Sombrero galaxy, NGC 4594, contains the most numerous globular cluster system of any nearby spiral. It is an ideal candidate in which to study the globular clusters and contrast them with those in Local Group spirals. Here we present B and I imaging from the CTIO Schmidt telescope which gives a field-of-view of 31' x 31'. Using DAOPHOT we have detected over 400 globular clusters and derived their magnitudes, B--I colors and photometric metallicities. We have attempted to separate our sample into disk and bulge/halo globular cluster populations, based on location in the galaxy. There is some evidence that the disk population is more metal--rich than the bulge/halo globular clusters, however contamination, dust reddening and small number statistics makes this result very tentative. We find that the median metallicity of the bulge/halo globular clusters is [Fe/H] = -0.8. This metallicity is consistent with previous estimates based on smaller samples. It is also similar to the metallicity predicted by the globular cluster metallicity -- galaxy luminosity relation. As with our Galaxy, there is no radial metallicity gradient in the halo globular clusters. This suggests that the spheriodal component of NGC 4594 did not form by a dissipational process.Comment: 7 pages, Latex. To be published in the Astronomical Journal. Full paper available at http://www.ucolick.org/~forbes/home.htm

A Mythology for England

As J.R.R. Tolkien developed a mythology for his invented languages to dwell and grow in, he found himself increasingly drawn to satisfy himself his desire for a true English epic. Tolkien this encompassed elements of English geography, language, and mythology within his geography, languages, and mythology, as demonstrated through an examination of five figures of Tolkien\u27s mythology, Eärendil, Ermon, and Elmir, Ælfwine, and Ingwë

Designing intervention strategies for forestry seedling production in the Philippines

The forest nursery sector in the Philippines is not delivering high quality planting stock of a wide species base for tree farming and reforestation programs. The ACIAR Seedling Enhancement Project, funded by ACIAR, has been implemented to address this problem. The project uses a systems approach and has developed a Bayesian Belief Network (BBN) to analyse the forest nursery system and investigate the relationship between factors affecting seedling quality and the operational effectiveness of the forest nursery sector. A workshop with various stakeholders was held to demonstrate the interactions among nursery system components using the BBN and to identify potential policy interventions. Stakeholders revealed three main themes, namely Market for seedling and timber (i.e. poor market of timber and seedlings), Funding of nurseries (i.e. budget) and Seedling quality (i.e. low quality of forest reproductive material) as potential leverage areas for improving the operational effectiveness of the forest nursery sector. Nursery accreditation, capacity building, increased seedling sales and an improved pathway of high quality germplasm were identified as major interventions. Further, policy reform was deemed necessary to create market-driven incentives for accredited nurseries and for government nursery operation to support the existence of private nurseries. The Seedling Enhancement Project has commenced pilot testing specific policy interventions

Design for validation: An approach to systems validation

Every complex system built is validated in some manner. Computer validation begins with review of the system design. As systems became too complicated for one person to review, validation began to rely on the application of adhoc methods by many individuals. As the cost of the changes mounted and the expense of failure increased, more organized procedures became essential. Attempts at devising and carrying out those procedures showed that validation is indeed a difficult technical problem. The successful transformation of the validation process into a systematic series of formally sound, integrated steps is necessary if the liability inherent in the future digita-system-based avionic and space systems is to be minimized. A suggested framework and timetable for the transformtion are presented. Basic working definitions of two pivotal ideas (validation and system life-cyle) are provided and show how the two concepts interact. Many examples are given of past and present validation activities by NASA and others. A conceptual framework is presented for the validation process. Finally, important areas are listed for ongoing development of the validation process at NASA Langley Research Center

TEXAS AGRICULTURE BY CONGRESSIONAL DISTRICT: 1993-1996

Texas Agriculture by Congressional Districts: 1993-96 is an update of previous editions of this publication. Commodity sales by county are estimates made by county agents and, therefore, are not official. In all but 4 of 30 Texas congressional districts, production agriculture accounts for over $100 million in sales. In 18 of the districts, farm program commodities represent over$50 million in sales.Production Economics,

Software Defined Radio Architecture Contributions to Next Generation Space Communications

Space communications architecture concepts, comprising the elements of the system, the interactions among them, and the principles that govern their development, are essential factors in developing National Aeronautics and Space Administration (NASA) future exploration and science missions. Accordingly, vital architectural attributes encompass flexibility, the extensibility to insert future capabilities, and to enable evolution to provide interoperability with other current and future systems. Space communications architectures and technologies for this century must satisfy a growing set of requirements, including those for Earth sensing, collaborative observation missions, robotic scientific missions, human missions for exploration of the Moon and Mars where surface activities require supporting communications, and in-space observatories for observing the earth, as well as other star systems and the universe. An advanced, integrated, communications infrastructure will enable the reliable, multipoint, high-data-rate capabilities needed on demand to provide continuous, maximum coverage for areas of concentrated activity. Importantly, the cost/value proposition of the future architecture must be an integral part of its design; an affordable and sustainable architecture is indispensable within anticipated future budget environments. Effective architecture design informs decision makers with insight into the capabilities needed to efficiently satisfy the demanding space-communication requirements of future missions and formulate appropriate requirements. A driving requirement for the architecture is the extensibility to address new requirements and provide low-cost on-ramps for new capabilities insertion, ensuring graceful growth as new functionality and new technologies are infused into the network infrastructure. In addition to extensibility, another key architectural attribute of the space communication equipment's interoperability with other NASA communications systems, as well as those communications and navigation systems operated by international space agencies and civilian and government agencies. In this paper, we review the philosophies, technologies, architectural attributes, mission services, and communications capabilities that form the structure of candidate next-generation integrated communication architectures for space communications and navigation. A key area that this paper explores is from the development and operation of the software defined radio for the NASA Space Communications and Navigation (SCaN) Testbed currently on the International Space Station (ISS). Evaluating the lessons learned from development and operation feed back into the communications architecture. Leveraging the reconfigurability provides a change in the way that operations are done and must be considered. Quantifying the impact on the NASA Space Telecommunications Radio System (STRS) software defined radio architecture provides feedback to keep the standard useful and up to date. NASA is not the only customer of these radios. Software defined radios are developed for other applications, and taking advantage of these developments promotes an architecture that is cost effective and sustainable. Developments in the following areas such as an updated operating environment, higher data rates, networking and security can be leveraged. The ability to sustain an architecture that uses radios for multiple markets can lower costs and keep new technology infused

Clustering in 18O - absolute determination of branching ratios via high-resolution particle spectroscopy

The determination of absolute branching ratios for high-energy states in light nuclei is an important and useful tool for probing the underlying nuclear structure of individual resonances: for example, in establishing the tendency of an excited state towards α -cluster structure. Difficulty arises in measuring these branching ratios due to similarities in available decay channels, such as ( 18 O, n ) and ( 18 O, 2 n ), as well as differences in geometric efficiencies due to population of bound excited levels in daughter nuclei. Methods are presented using Monte Carlo techniques to overcome these issues

Disparities in Child and Adolescent Psychoactive Medication Prescription Practices by Race and Ethnicity

Key Points: (1) Compared to their non-Latino white counterparts, children and adolescents from racial-ethnic minority groups in the U.S. are less likely to receive prescriptions for psychoactive medication; (2) Racial-ethnic minority children and adolescents are also significantly less likely to receive mental health care; (3) Controlling for access to mental health care and for geographic variation reduces but does not eliminate variations in psychoactive prescriptions by race and ethnicity; (4) Controlling for mental health need and level of impairment does not eliminate variations in psychoactive prescriptions by race and ethnicity; (5) Reducing disparities will require coordinated efforts to educate families and providers, promotion of evidence-based practices, steps to overcome geographic and language barriers, and additional research for understanding the underlying reasons for variations in prescription patterns

VLBA Imaging of the OH Maser in IIIZw35

We present a parsec-scale image of the OH maser in the nucleus of the active galaxy IIIZw35, made using the Very Long Baseline Array at a wavelength of 18 cm. We detected two distinct components, with a projected separation of 50 pc (for D=110 Mpc) and a separation in Doppler velocity of 70 km/s, which contain 50% of the total maser flux. Velocity gradients within these components could indicate rotation of clouds with binding mass densities of ~7000 solar masses per cubic parsec, or total masses of more than 500,000 solar masses. Emission in the 1665-MHz OH line is roughly coincident in position with that in the 1667-MHz line, although the lines peak at different Doppler velocities. We detected no 18 cm continuum emission; our upper limit implies a peak apparent optical depth greater than 3.4, assuming the maser is an unsaturated amplifier of continuum radiation.Comment: 10 pages, 3 figure

9286 Stars: An Agglomeration of Stellar Polarization Catalogs

This is a revision. The revisions are minor. The new version of the catalog should be used in preference to the old. The most serious error in the older version was that $\theta_diff$ was incorrect, being sometimes far too large, for Reiz and Franco entries; the correct values are all zero for that reference. We present an agglomeration of stellar polarization catalogs with results for 9286 stars. We have endeavored to eliminate errors, provide accurate (arcsecond) positions, sensibly weight multiple observations of the same star, and provide reasonable distances. This catalog is included as an ASCII file (catalog.txt) in the source of this submission.Comment: The most serious error in the older version was that $\theta_diff$ was incorrect, being sometimes far too large, for Reiz and Franco entries; the correct values are all zero for that reference. 11 pages, no figures. Accepted for Astronomical Journal. Catalog also available as an ASCII file by anonymous FTP from ftp://vermi.berkeley.edu/pub/polcat/p14.ou