THE ADOPTION AND DIFFUSION OF LEVEL FIELDS AND BASINS

Strategic investments in agriculture often are lumpy and irreversible, with significant impacts on operating and fixed costs. Leveling cotton fields to zero slope in central Arizona is a strategic decision made by relatively younger farmers who are farming fine-textured soils in irrigation districts with higher expected water costs. The diffusion of the technology across the region between 1968-89 appears to be both a function of institutional changes (e.g., the Groundwater Management Act of 1980, the Central Arizona Project) and the long-run expected price changes induced by these new policies.Crop Production/Industries,

CCS Imaging of the Starless Core L1544: An Envelope with Infall and Rotation

We have carried out observations of the starless core L1544 in the CCS (J_N=3_2-2_1) line at 9 millimeters wavelength using the BIMA array. The maps show an elongated condensation, 0.15 x 0.045 pc in size, with stronger emission at the edges. The appearance is consistent with a flattened, ringlike structure viewed at high inclination to the line of sight. The CCS molecule is likely heavily depleted in the inner part of the core. The position velocity diagram along the major axis shows a remarkable pattern, a "tilted ellipse", that can be reproduced by a simple model ring with motions of both infall and rotation. The models suggest comparable velocities for infall and rotation, ~0.1 km/s, in the outermost envelope, at radius 15000 AU.Comment: 14 pages, 4 figures, AAS-LaTex v4.0, will be published in ApJ

Validation of a novel scoring system for changes in skeletal manifestations of hypophosphatasia in newborns, infants, and children: The Radiographic Global Impression of Change scale

Hypophosphatasia (HPP) is the heritable metabolic disease characterized by impaired skeletal mineralization due to low activity of the tissue-nonspecific isoenzyme of alkaline phosphatase. Although HPP during growth often manifests with distinctive radiographic skeletal features, no validated method was available to quantify them, including changes over time. We created the Radiographic Global Impression of Change (RGI-C) scale to assess changes in the skeletal burden of pediatric HPP. Site-specific pairs of radiographs of newborns, infants, and children with HPP from three clinical studies of asfotase alfa, an enzyme replacement therapy for HPP, were obtained at baseline and during treatment. Each pair was scored by three pediatric radiologists ( raters ), with nine raters across the three studies. Intrarater and interrater agreement was determined by weighted Kappa coefficients. Interrater reliability was assessed using intraclass correlation coefficients (ICCs) and by two-way random effects analysis of variance (ANOVA) and a mixed-model repeated measures ANOVA. Pearson correlation coefficients evaluated relationships of the RGI-C to the Rickets Severity Scale (RSS), Pediatric Outcomes Data Collection Instrument Global Function Parent Normative Score, Childhood Health Assessment Questionnaire Disability Index, 6-Minute Walk Test percent predicted, and Z-score for height in patients aged 6 to 12 years at baseline. Eighty-nine percent (8/9) of raters showed substantial or almost perfect intrarater agreement of sequential RGI-C scores (weighted Kappa coefficients, 0.72 to 0.93) and moderate or substantial interrater agreement (weighted Kappa coefficients, 0.53 to 0.71) in patients aged 0 to 12 years at baseline. Moderate-to-good interrater reliability was observed (ICC, 0.57 to 0.65). RGI-C scores were significantly (p ≤ 0.0065) correlated with the RSS and with measures of global function, disability, endurance, and growth in the patients aged 6 to 12 years at baseline. Thus, the RGI-C is valid and reliable for detecting clinically important changes in skeletal manifestations of severe HPP in newborns, infants, and children, including during asfotase alfa treatment. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc

A numerical study of the correspondence between paths in a causal set and geodesics in the continuum

This paper presents the results of a computational study related to the path-geodesic correspondence in causal sets. For intervals in flat spacetimes, and in selected curved spacetimes, we present evidence that the longest maximal chains (the longest paths) in the corresponding causal set intervals statistically approach the geodesic for that interval in the appropriate continuum limit.Comment: To the celebration of the 60th birthday of Rafael D. Sorki

Table of contents and editorial information for Vol. 15, no. 3, Fall 1988

Table of contents and editorial information for Vol. 15, no. 3, Fall 198

Vitis riparia Michx.

https://thekeep.eiu.edu/herbarium_specimens_byname/19457/thumbnail.jp

Educational Considerations, vol. 15(3) Full Issue

Educational Considerations, vol.15 (3) Fall 1988 - Full issu

Paper Session II-A - Gamma Ray Observatory: Viewing the Violent Universe

The Gamma Ray Observatory (GRO), the second in NASA\u27s series of Great Observatories, is the next major thrust in astrophysics. The 35,000 pound satellite is scheduled for a Shuttle launch in April 1991. By observing the sky in gamma rays, which are the most energetic form of electromagnetic radiation, GRO will be exploring some of the most violent phenomena in the universe. The four instruments on the GRO will allow a comprehensive look at gamma ray emission from such sites as supernova remnants, pulsars, the Galactic Center, and quasars. GRO will also investigate intriguing astrophysical processes such as the origin of gamma-ray bursts, the balance of cosmic rays with gas and magnetic field in the Galaxy, and matter-antimatter annihilation. Plans for the mission include an all-sky survey during the first year, followed by selected observations in the second and succeeding years

Foreword

A long-standing struggle within education has been how to best maximize and diversify the vast wealth of resources present in communities in a manner which best addresses the needs of children