Evidence for glaciation in Elysium

It is suggested that certain landforms in the Elysium region of Mars provide strong evidence for glaciation. Landscapes related to subglacial volcanism suggest that ice was a primary agent in the development of Elysium

Grain Marketing Strategies of North Dakota Grain Farmers

The basic objective of this report is to discuss the factors considered and the methods that are used by small-grain farmers in the marketing of their products. The figures and discussions which appear in this report are not meant to be an inclusive average of all farmers in North Dakota, but rather a consensus of specific groups of farmers engaged primarily in producing small-grains with limited income from other sources. It is hoped that this report will serve as a useful reference in helping North Dakota small-grain producers identify possible marketing alternatives and strategies available.Marketing,

Analyzing Repeated Measures Marginal Models on Sample Surveys with Resampling Methods

Packaged statistical software for analyzing categorical, repeated measures marginal models on sample survey data with binary covariates does not appear to be available. Consequently, this report describes a customized SAS program which accomplishes such an analysis on survey data with jackknifed replicate weights for which the primary sampling unit information has been suppressed for respondent confidentiality. First, the program employs the Macro Language and the Output Delivery System (ODS) to estimate the means and covariances of indicator variables for the response variables, taking the design into account. Then, it uses PROC CATMOD and ODS, ignoring the survey design, to obtain the design matrix and hypothesis test specifications. Finally, it enters these results into another run of CATMOD, which performs automated direct input of the survey design specifications and accomplishes the appropriate analysis. This customized SAS program can be employed, with minor editing, to analyze general categorical, repeated measures marginal models on sample surveys with replicate weights. Finally, the results of our analysis accounting for the survey design are compared to the results of two alternate analyses of the same data. This comparison confirms that such alternate analyses, which do not properly account for the design, do not produce useful results.

Public School Choice and Desegregation in Arkansas

Public school choice is an umbrella term for policies that allow students to enroll in a public school other than their residentially-assigned school. Public school choice, also called openenrollment, is typically divided into two categories: intra-district choice, transfers to schools in the same district, and inter-district choice, transfers to schools in other districts

Alluvial Fan Development at Franklin Bluffs, Alaska

This paper is concerned with the developmental history of alluvial fans forming in a tundra climate. The study was made at Franklin Bluffs, Alaska (69° 48\u27 - 70° 00\u27 N, 148° 40\u27 W), during the summer of 1961. The area is an ideal place in which to study the developmental history of alluvial fans in that so many stages are present in a relatively small area. A theoretical sequence of fan development was set up, illustrated by examples from the Franklin Bluffs, which show how certain characteristics of an alluvial fan, forming in a tundra climate, change as the sequence advances. The sequence was designated A, B, C, D, and E, where A is the youngest, near talus cone stage, and E is the oldest, near graded stage. Certain characteristics were found to constitute a continuum of changes in the sequence. The two most continuously changing factors are the difference in slope, between that of the drainage area and that of the fan, and the relative size of each fan -vs- drainage area. Also, in the progress of the sequence, the intensity of mass wasting decreases. Related to the type and intensity of mass-wasting and the amount and size distribution of surficial rock material and the amount and type of vegetation. The climax of the sequence is characterized by the approach to a well vegetated graded stage on which a permanent channel forms if sufficiently continuous discharge is present

Testing Gravity in the Outer Solar System: Results from Trans-Neptunian Objects

The inverse square law of gravity is poorly probed by experimental tests at distances of ~ 10 AUs. Recent analysis of the trajectory of the Pioneer 10 and 11 spacecraft have shown an unmodeled acceleration directed toward the Sun which was not explained by any obvious spacecraft systematics, and occurred when at distances greater than 20 AUs from the Sun. If this acceleration represents a departure from Newtonian gravity or is indicative of an additional mass distribution in the outer solar system, it should be detectable in the orbits of Trans-Neptunian Objects (TNOs). To place limits on deviations from Newtonian gravity, we have selected a well observed sample of TNOs found orbiting between 20 and 100 AU from the Sun. By examining their orbits with modified orbital fitting software, we place tight limits on the perturbations of gravity that could exist in this region of the solar system.Comment: 20 pages, 4 figures, 2 tables, uses AASTex v5.x macro

Demonstration project in low-cost shoreline erosion control : final report to County Administrator, County of Accomack, Virginia

·1ow cost erosion control structures were installed at ten shoreline sites located in the lower Chesapeake Bay and on the Potomac and Rappahannock Rivers to further test the applicability of the perched beach concept under diverse littoral environments. The perched beach is achieved via installation of a low sill parallel to the shoreline. The objective of the sill is to provide a partial barrier behind which an elevated (perched) beach is accreted. When successful, ~he perched beach backshore and foreshore acts to reduce the frequency of direct wave attack against the fastland and thereby reducing the erosion rate. In this study, sills were used in conjunction with existing groins as well as alone. Some testing was performed on the use of a spur with existing groins as a device to prevent the formation of a downdrift erosion notch where the groin intersects the fastland. The sills were formed with a series of large PVC-coated nylon bags hydraulically filled with sand or with stone filled gabions. In one case compacted used auto tires were utilized as fill for a gabion. Evaluation of the response to the structures was based upon a series of surveyed beach profiles at each site and sequential photography. At each site the beach profiles were surveyed for several months prior to and following the installation of the various structures. Additional profiles were run adjacent to the treated areas. The structures were emplaced between late March and early June of 1978

Analyzing Repeated Measures Marginal Models on Sample Surveys with Resampling Methods

Packaged statistical software for analyzing categorical, repeated measures marginal models on sample survey data with binary covariates does not appear to be available. Consequently, this report describes a customized SAS program which accomplishes such an analysis on survey data with jackknifed replicate weights for which the primary sampling unit information has been suppressed for respondent confidentiality. First, the program employs the Macro Language and the Output Delivery System (ODS) to estimate the means and covariances of indicator variables for the response variables, taking the design into account. Then, it uses PROC CATMOD and ODS, ignoring the survey design, to obtain the design matrix and hypothesis test specifications. Finally, it enters these results into another run of CATMOD, which performs automated direct input of the survey design specifications and accomplishes the appropriate analysis. This customized SAS program can be employed, with minor editing, to analyze general categorical, repeated measures marginal models on sample surveys with replicate weights. Finally, the results of our analysis accounting for the survey design are compared to the results of two alternate analyses of the same data. This comparison confirms that such alternate analyses, which do not properly account for the design, do not produce useful results