Research Notes: Soybean seed β-amylase variants

Hildebrand and Hymowitz (1980a) reported that two soybean genotypes were found that lack detectable seed a- amylase activity . The cultivar \u27Chestnut\u27 produces an inactive a- amylase protein, Span (Hildebrand and Hymowitz , 1980b) ; \u27Altona\u27 is a mixture of genotypes that have a a-amylase protein of normal activity (sp1b) or lack it entirely (sp1) (Hildebrand and Hymowitz , 1980b) . Chestnut was selected from \u27Habaro\u27 and introduced into the U.S. as PI 20,405 in 1906 from Kharbarovsk, USSR (Hymowitz et al ., 1977)

Research Notes : Seed acid phosphatase genotypes of cultivars in the USDA soybean collection

Soybeans have three cultivar-specific electrophoretic fonns of a seed acid phosphatase (Gorman and Kiang, 1977). Hildebrand et al. (1980) reported that the three acid phosphata se fonns are inherited as codominant alleles at a single locus. The symbol Ap^a was assigned to the slow form, Ap^b to the intermediate and Ap^c to the fast form

PRINCIPLE AND TVVO FORMS OF SWIMMING PROPULSION

Propulsion in water is primarily done by generating torque in the shoulder, hip, knee, and ankle. To do this water resistance is used as support. By the of arm movements the body is pulled through the water, by the leg movements it is pushed. Locomotion is also found without any direct backward motion of the water

Resolving velocity space dynamics in continuum gyrokinetics

Many plasmas of interest to the astrophysical and fusion communities are weakly collisional. In such plasmas, small scales can develop in the distribution of particle velocities, potentially affecting observable quantities such as turbulent fluxes. Consequently, it is necessary to monitor velocity space resolution in gyrokinetic simulations. In this paper, we present a set of computationally efficient diagnostics for measuring velocity space resolution in gyrokinetic simulations and apply them to a range of plasma physics phenomena using the continuum gyrokinetic code GS2. For the cases considered here, it is found that the use of a collisionality at or below experimental values allows for the resolution of plasma dynamics with relatively few velocity space grid points. Additionally, we describe implementation of an adaptive collision frequency which can be used to improve velocity space resolution in the collisionless regime, where results are expected to be independent of collision frequency.Comment: 20 pages, 11 figures, submitted to Phys. Plasma

A 3D VIDEO TECHNIQUE FOR ANALYSIS OF SWIMMING IN A FLUME

The photogrammetric evaluation of video recordings in a flume is complicated. Depending on the perspectives of cameras strong geometric distortions occur. Very short focal length, caused by lack of space, and transitions waterfair or waterfglassfair result in distortions in the recorded images. Using the photogrammetric evaluation we have to correct these geometric errors. The technological solution (recording setup, calibration, measurement in the images) for the swimming flume Hamburg is presented. Two lateral cameras, convergently geared, are applied to record the swimmer, simultaneously under and above the water. For the calibration of cameras a fine-meshed grid frame was placed several times in the object space. The measurements within the video image sequences were done analytically and simultaneously with special software

Massive Protoplanetary Disks in the Trapezium Region

(abridged) We determine the disk mass distribution around 336 stars in the young Orion Nebula cluster by imaging a 2.5' x 2.5' region in 3 mm continuum emission with the Owens Valley Millimeter Array. For this sample of 336 stars, we observe 3 mm emission above the 3-sigma noise level toward ten sources, six of which have also been detected optically in silhouette against the bright nebular background. In addition, we detect 20 objects that do not correspond to known near-IR cluster members. Comparisons of our measured fluxes with longer wavelength observations enable rough separation of dust emission from thermal free-free emission, and we find substantial dust emission toward most objects. For the ten objects detected at both 3 mm and near-IR wavelengths, eight exhibit substantial dust emission. Excluding the high-mass stars and assuming a gas-to-dust ratio of 100, we estimate circumstellar masses ranging from 0.13 to 0.39 Msun. For the cluster members not detected at 3 mm, images of individual objects are stacked to constrain the mean 3 mm flux of the ensemble. The average flux is detected at the 3-sigma confidence level, and implies an average disk mass of 0.005 Msun, comparable to the minimum mass solar nebula. The percentage of stars in Orion surrounded by disks more massive than ~0.1 Msun is consistent with the disk mass distribution in Taurus, and we argue that massive disks in Orion do not appear to be truncated through close encounters with high-mass stars. Comparison of the average disk mass and number of massive dusty structures in Orion with similar surveys of the NGC 2024 and IC 348 clusters constrains the evolutionary timescales of massive circumstellar disks in clustered environments.Comment: 27 pages, including 7 figures. Accepted by Ap

Pair distribution function and structure factor of spherical particles

The availability of neutron spallation-source instruments that provide total scattering powder diffraction has led to an increased application of real-space structure analysis using the pair distribution function. Currently, the analytical treatment of finite size effects within pair distribution refinement procedures is limited. To that end, an envelope function is derived which transforms the pair distribution function of an infinite solid into that of a spherical particle with the same crystal structure. Distributions of particle sizes are then considered, and the associated envelope function is used to predict the particle size distribution of an experimental sample of gold nanoparticles from its pair distribution function alone. Finally, complementing the wealth of existing diffraction analysis, the peak broadening for the structure factor of spherical particles, expressed as a convolution derived from the envelope functions, is calculated exactly for all particle size distributions considered, and peak maxima, offsets, and asymmetries are discussed.Comment: 7 pages, 6 figure

Research Notes : Linkage tests between the Ap and W1 loci

The F2 generation of the cross \u27Williams\u27 x \u27Manchu (Madison)\u27 was used to determine if the Ap and W1 loci were linked. The Ap locus controls a seed acid phosphatase which exists in the germplasm in three different electrophoretic forms controlled by three codominant alleles -- Ap^a, Ap^b and Ap^c (Hildebrand et al., 1980). The W1 locus controls flower color--purple (W1) and white (w1)

Massive Quiescent Cores in Orion. -- II. Core Mass Function

We have surveyed submillimeter continuum emission from relatively quiescent regions in the Orion molecular cloud to determine how the core mass function in a high mass star forming region compares to the stellar initial mass function. Such studies are important for understanding the evolution of cores to stars, and for comparison to formation processes in high and low mass star forming regions. We used the SHARC II camera on the Caltech Submillimeter Observatory telescope to obtain 350 \micron data having angular resolution of about 9 arcsec, which corresponds to 0.02 pc at the distance of Orion. Our analysis combining dust continuum and spectral line data defines a sample of 51 Orion molecular cores with masses ranging from 0.1 \Ms to 46 \Ms and a mean mass of 9.8 \Ms, which is one order of magnitude higher than the value found in typical low mass star forming regions, such as Taurus. The majority of these cores cannot be supported by thermal pressure or turbulence, and are probably supercritical.They are thus likely precursors of protostars. The core mass function for the Orion quiescent cores can be fitted by a power law with an index equal to -0.85$\pm$0.21. This is significantly flatter than the Salpeter initial mass function and is also flatter than the core mass function found in low and intermediate star forming regions. Thus, it is likely that environmental processes play a role in shaping the stellar IMF later in the evolution of dense cores and the formation of stars in such regions.Comment: 30 pages, 10 figures, accepted by Ap

Far infrared and submillimeter brightness temperatures of the giant planets

The brightness temperatures of Jupiter, Saturn, Uranus, and Neptune in the range 35 to 1000 micron. The effective temperatures derived from the measurements, supplemented by shorter wavelength Voyager data for Jupiter and Saturn, are 126.8 + or - 4.5 K, 93.4 + or - 3.3 K, 58.3 + or - 2.0 K, and 60.3 + or - 2.0 K, respectively. The implications of the measurements for bolometric output and for atmospheric structure and composition are discussed. The temperature spectrum of Jupiter shows a strong peak at approx. 350 microns followed by a deep valley at approx. 450 to 500 microns. Spectra derived from model atmospheres qualitatively reproduced these features but do not fit the data closely