Chloroplast and Mitochondrial: DNA Polymerases From Cultured Soybean Cells

DNA polymerases were purified from chloroplasts and mitochondria of cultured Glycine max cells. The chloroplast enzyme exists in two forms which are indistinguishable from each other biochemically. All three organellar enzymes have an estimated molecular weight of 85,000 to 90,000 and prefer poly(rA)dT12-18 over activated DNA as a template in vitro. Maximum activity of the chloroplast and mitochondrial DNA polymerases requires KCI and a reducing agent, and the enzymes are completely resistant to inhibitors of DNA polymerase a. Taken together, these properties classify the soybean organellar enzymes as DNA polymerases y. A unique feature that distinguishes the plant enzymes from their animal counterparts is their resistance to dideoxyribonucleotides

Optimization Analysis of a Simple Position Control System

One of the problem areas of modern optimal control theory is the definition of suitable performance indices. This thesis demonstrates a rational method of establishing a quadratic performance index derived from a desired system model. Specifically, a first order model is used to provide a quadratic performance index for which a second order system is optimized. Extension of the method to higher order systems, while requiring more computations, involves no additional theoretical complexities

The Stellar and Gaseous Contents of the Orion Dwarf Galaxy

We present new KPNO 0.9-m optical and VLA HI spectral line observations of the Orion dwarf galaxy. This nearby (D ~ 5.4 Mpc), intermediate-mass (M_dyn = 1.1x10^10 Solar masses) dwarf displays a wealth of structure in its neutral ISM, including three prominent "hole/depression" features in the inner HI disk. We explore the rich gas kinematics, where solid-body rotation dominates and the rotation curve is flat out to the observed edge of the HI disk (~6.8 kpc). The Orion dwarf contains a substantial fraction of dark matter throughout its disk: comparing the 4.7x10^8 Solar masses of detected neutral gas with estimates of the stellar mass from optical and near-infrared imaging (3.7x10^8 Solar masses) implies a mass-to-light ratio of ~13. New H alpha observations show only modest-strength current star formation (~0.04 Solar masses per year); this star formation rate is consistent with our 1.4 GHz radio continuum non-detection.Comment: Astronomical Journal, in press. Full-resolution version available from http://www.macalester.edu/~jcannon/pubs.htm

Just A Little Bit South Of North Carolina

Illustration of sign that says \u27South Carolina\u27 and points to the right; Bird on top of signhttps://scholarsjunction.msstate.edu/cht-sheet-music/7832/thumbnail.jp

Book Reviews

Review of the following books: Nearby History: Exploring the Past Around You by David E. Kyvig and Myron A. Marty; The Forerunners: The Tragic Story of 156 Down-East Americans Led to Jaffa in 1866 by Charismatic G.J. Adams to Plant the Seeds of Modern Israel by Reed M. Holmes; Islands of Maine: Where America Really Began by Bill Caldwell; Foundations of Northeast Archaeology edited by Dean R. Snow; A Short History of the American Locomotive Builders in the Steam Era by John H. Whit

Validation of electron density profiles derived from oblique ionograms over the United Kingdom

Inversion algorithms are available to derive the vertical electron density profile at the midpoint of an oblique sounder path. The techniques open up the possibility of monitoring the ionosphere at otherwise inaccessible locations, such as over sea or inhospitable terrain. A new method of monitoring the ionosphere based on radio tomography can be used to create two-dimensional images of electron density. The results in this paper compare midpoint profiles derived from oblique ionograms with corresponding profiles obtained from tomographic images of electron density and from a vertical ionospheric sounder. The comparisons illustrate the oblique sounder inversion technique and its inherent limitations. The results provide useful information on the complementary nature of the separate ionospheric measurement techniques and have implications for the use of these measurements as inputs to real-time ionospheric models

Sample size for inspection intended to manage risk within mixed consignments

The identification of a lot, and the size of the random sample taken for plant products, is justified by appeal to International Standards for Phytosanitary Measures No. 31, “Methodologies for Sampling of Consignments”. ISPM 31 notes that “A lot to be sampled should be a number of units of a single commodity identifiable by its homogeneity [...]” and “Treating multiple commodities as a single lot for convenience may mean that statistical inferences cannot be drawn from the results of the sampling.” However, consignments are frequently heterogeneous, either because the same commodities have multiple sources or because there are several different commodities. The ISPM 31 prescription creates a substantial burden on border inspection because it suggests that heterogeneous populations must be split into homogeneous sub-populations from which separate samples of nominal size must be taken. We demonstrate that if consignments with known heterogeneity are treated as stratified populations and the random sample of units is allocated proportionally based on the number of units in each stratum, then the nominal sensitivity at the consignment level is achieved if our concern is the level of contamination in the entire consignment taken as a whole. We argue that unknown heterogeneity is no impediment to appropriate statistical inference. We conclude that the international standard is unnecessarily restrictive