USING NATURE AS BOTH MENTOR AND MODEL: ANIMAL WELFARE RESEARCH AND DEVELOPMENT IN SUSTAINABLE SWINE PRODUCTION

Livestock Production/Industries,

The Construction of a Racquetball Skills Test Battery for Beginning College Women

The sport of racquetball has rapidly gained popularity throughout the country. Racquetball evolved from the game of paddleball, and confusion in the use of these two terms continues to exist. Paddleball is played with a solid paddle and a Pennsylvania 100 ball which has a pin hole through the surface. Racquetball is laying with a strung racquet and a Seamless 558 ball. The recently organized (1968) International Racquetball Association sponsors singles and doubles competition for men and women of all ages, from under nineteen(Juniors) to over forty(Masters). Racquetball has also experienced rapid growth in popularity among college women as a recreational and fitness activity. This growth has requested in an increased demand for basic instruction courses in racquetball. A review of existing skills tests disclosed a lack of tools for the assessment of racquetball skills. There is a definite need to devise valid, reliable tests to aid in teacher evaluation of the student and self-evaluation in racquetball. The purpose of his study was to develop a battery of skills tests that would accurately measure playing ability of college women enrolled in beginning classes of racquetball

FARM ANIMAL WELFARE: CRISIS OR OPPORTUNITY FOR AGRICULTURE?

Livestock Production/Industries,

Waypoint Following Dynamics of a Quaternion Error Feedback Attitude Control System

Closed-loop attitude steering can be used to implement a non-standard attitude maneuver by using a conventional attitude control system to track a non-standard attitude profile. The idea has been employed to perform zero-propellant maneuvers on the International Space Station and minimum time maneuvers on NASA's TRACE space telescope. A challenge for operational implementation of the idea is the finite capacity of a space vehicle's command storage buffer. One approach to mitigate the problem is to downsample-and-hold the attitude commands as a set of waypoints for the attitude control system to follow. In this paper, we explore the waypoint following dynamics of a quaternion error feedback control law for downsample-and-hold. It is shown that downsample-and-hold induces a ripple between downsamples that causes the satellite angular rate to significantly overshoot the desired limit. Analysis in the $z$-domain is carried out in order to understand the phenomenon. An interpolating Chebyshev-type filter is proposed that allows attitude commands to be encoded in terms of a set of filter coefficients. Using the interpolating filter, commands can be issued at the ACS rate but with significantly reduced memory requirements. The attitude control system of NASA's Lunar Reconnaissance Orbiter is used as an example to illustrate the behavior of a practical attitude control system.Comment: 24 pages; 11 figure

Specific Isotopic Labeling and Photooxidation-linked Structural Changes in the Manganese-stabilizing Subunit of Photosystem II

Photosystem II (PSII) oxidizes water to molecular oxygen; the catalytic site is a cluster of four manganese ions. The catalytic site undergoes four sequential light-driven oxidation steps to form oxygen; these sequentially oxidized states are referred to as the Sn states, where n refers to the number of oxidizing equivalents stored. The extrinsic manganese stabilizing protein (MSP) of PSII influences the efficiency and stability of the manganese cluster, as well as the rates of the S state transitions. To understand how MSP influences photosynthetic water oxidation, we have employed isotope editing and difference Fourier transform infrared spectroscopy. MSP was expressed in Escherichia coli under conditions in which MSP aspartic and glutamic acid residues label at yields of 65 and 41%, respectively. Asparagine and glutamine were also labeled by this approach. GC/MS analysis was consistent with minimal scrambling of label into other amino acid residues and with no significant scrambling into the peptide bond. Selectively labeled MSP was then reconstituted to PSII, which had been stripped of native MSP. Difference Fourier transform infrared spectroscopy was used to probe the S 1QA to S2QA- transition at 200 K, as well as the S1QB to S2Q B- transition at 277 K. These experiments show that aspargine, glutamine, and glutamate residues in MSP are perturbed by photooxidation of manganese during the S1 to S2 transition

Some Effects Of Enzyme Supplementation And Various Wheat Bran Levels In A Broiler Diet On Apparent Digestibility

It is generally recognized that birds do not have an enzyme in their digestive fluid which digests cellulose. However, cellulosic materials are major renewable resources available in large quantities which need to be properly utilized to help meet our needs for energy, chemicals, food and feed for a long-range solution. A variety of lignocellulosic materials containing acid-detergent fibers, are available and microorganisms capable of degrading either one or more of the three main constituents, viz., cellulose, hemicelluose and lignin, have been studied. A further variety of strategies are being explored, including thermal methods of degradation such as pyrolysis or biological methods such as enzymatic hydrolysis and fermentation

The Effect Of Cellulase Supplementation And Various Wheat Bran Levels In Broiler Diets

It is a widely known fact that fibrous material is generally not well assimilated by a growing chick. Furthermore, the effect on the growth of a chick sometimes may be quite derogatory, depending on the quantity of the fibrous material used in the diet. This effect is generally considered to be attributable to a reduction in the energy intake and might be caused by a specific effect of the cellulose itself or by some cellulose composition products

Geophysics

Contains reports on three research projects