Non-Measles Hemadsorption in a Cell Line Persistently Infected with Measles Virus (BGM/MV)

Adsorption of Rhesus monkey erythrocytes to the plasma membranes of measles virus infected cells is frequently carried out to detect the presence of plasma membrane-associated measles virus hemagglutinin. The hemagglutinin is a viral genome-coded structural glycoprotein of the measles virion that is associated with the plasma membrane of the host cell during measles virus replication. BGM/MV, anon-virogenic line of African green monkey kidney cells persistently-infected with measles virus, adsorbed Rhesus monkey erythrocytes in an inverse fashion relative to the number of cells present in the culture and the time post-seeding. Serological studies employing the hemadsorption-inhibition and membrane immunofluorescence assay procedures, suggested that this phenomenon was not mediated by the viral hemagglutinin. Assays for Simian virus-5 and mycoplasma, contaminating agents that induce erythrocyte adsorption, were negative. Incubation of BGM/MV cells at 33°C or with graded concentrations of fetal calf serum, to stimulate the metabolism of resting (Go) cells, suggested that adsorption was related to a phase(s) of the cell growth cycle other than Go₁, for adsorption was prolonged and stimulated in a dose-response fashion, respectively. Comparative adsorption studies employing the parent cell line (BGM), not infected with measles virus, were performed using various species of erythrocytes. While both cell lines adsorbed Rhesus monkey erythrocytes in an inverse fashion relative to cell density, differences were noted in the adsorption of some of the other species of erythrocytes. These data suggest that Rhesus monkey erythrocyte adsorption to BGM/MV cells was mediated by a receptor(s) of cellular origin

Livestock Enterprise Budgets for Iowa--2002

This publication contains estimates of production costs for common livestock enterprises in Iowa. Estimates are intended to refl ect average or above-average levels of management using common types of technology. Input prices reflect expected average price levels during the year.

A DECISION MODEL TO ASSESS CATTLE FEEDING PRICE RISK

Traditional break-even/fed cattle price projections do not provide adequate risk information to feeders, investors, lenders, and other stakeholders interested in cattle feeding decisions. The objectives of this study were two-fold: 1) develop a spreadsheet model that could estimate the net income distribution surrounding a cattle placement decision based on historical errors of futures based price forecasts, and 2) determine whether information generated from the model can be used to improve placement and marketing decisions. To accomplish objective 1, model was developed that could estimate the income distribution around a pen of cattle under a cash speculating and short hedge pricing strategy. Distribution estimates were based on 7 alternative forecast horizons and were derived from historical forecast errors. To accomplish objective 2, decision rules were developed that allow the feeder to specify the maximum probability he/she is willing to risk losing a specified level of income. These decision rules were compared to random and naive decision rules by simulating the outcomes over 168 discrete six months feeding periods between 1987 and 2000. Risk averse decision rules were successful in signaling highly unprofitable feeding periods, but also filtered out highly profitable feeding periods.Livestock Production/Industries, Marketing,

Flapping inertia for selected rotor blades

Aerodynamics of helicopter rotor systems cannot be investigated without consideration for the dynamics of the rotor. One of the principal properties of the rotor which affects the rotor dynamics is the inertia of the rotor blade about its root attachment. Previous aerodynamic investigation have been performed on rotor blades with a variety of planforms to determine the performance differences due to blade planform. The blades tested for this investigation have been tested on the U.S. Army 2 meter rotor test system (2MRTS) in the NASA Langley 14 by 22 foot subsonic tunnel for hover performance. This investigation was intended to provide fundamental information on the flapping inertia of five rotor blades with differing planforms. The inertia of the bare cuff and the cuff with a blade extension were also measured for comparison with the inertia of the blades. Inertia was determined using a swing testing technique, using the period of oscillation to determine the effective flapping inertia. The effect of damping in the swing test was measured and described. A comparison of the flapping inertials for rectangular and tapered planform blades of approximately the same mass showed the tapered blades to have a lower inertia, as expected

Economic Importance of The Iowa Egg Industry

The egg production and processing industry has a significant impact on Iowa's economy. And if consumer demand for eggs continues to increase and Iowa continues its commitment to grow the industry, expansion of Iowa's egg industry will continue.

ASSESSING THE COST OF BEEF QUALITY

The number of U.S. fed cattle marketed through a value based or grid marketing system is increasing dramatically. Most grids reward Choice or better quality grades and some pay premiums for red meat yield. The Choice-Select (C-S) price spread increased 55 percent, over $3/cwt between 1989-91 and 1999-01. However, there is a cost associated with pursuing these carcass premiums. This paper examines these tradeoffs both in the feedlot and in a retained ownership scenario. Correlations between carcass and performance traits resulted in economic tradeoffs that change across input costs and quality grade premiums and discounts. Feedlot profitability was largely determined by marbling, carcass weight, and feed efficiency. Carcass weight was most important at a low C-S spread. However, at average C-S spread and higher, marbling became the largest determinate of feedlot profits, and its importance increased with the C-S spread. Carcass weight and feed efficiency influence on feedlot profitability declined at higher C-S spreads. Rib-eye area was the fourth most important variable and declined in importance as marbling increased in importance. There is some indication that cows with lower feed costs also produce the most profitable calf for the feedlot, and vice-versa. The data suggests that cow size and marbling score are negatively correlated. The current trend toward wider C-S spreads and rewarding higher quality grading cattle places greater emphasis on marbling ability of calves. These correlations and results suggest that higher marbling is associated with lower cost cows to maintain.Livestock Production/Industries, Marketing,

Tiempoovillo: Paraguayan Experimental Theatre.

Tiempoovillo: Paraguayan Experimental Theatre

Diversified versus Specialized Swine and Grain Operations

Stochastic budget analysis compares diversified hog and grain operations to a specialized cash grain operation based on fixed labor resource. Benefits to diversified farms include decreased fertilizer costs due to manure application, shared machinery costs, and more stable grain price/cost assurances. As modeled manure application covers nearly all fertilizer requirements of the grain operation, greatly reducing fertilizer costs. The diversified operation is able to have dual-purpose tractors, enabling them to spread the tractor costs over more hours. Lastly, combining a grain and hog operation allows both enterprises to improve price assurance by treating the grain operation as a cost center. Grain is priced to the hogs at cost of production, thereby protecting the hog operation from volatility in the corn market. The risk reduction benefit of diversification is overshadowed when the 2002 Farm Bill is included in the analysis

An Economic Comparison Of Year Round vs Conventional Grazing Systems In Iowa

Year round grazing systems that utilize stockpiled forage and/or crop residue are often promoted as a way for Northern and Western cow-calf producers to reduce winter feeding costs and improve overall profitability. This study compared the profitability of a conventional spring calving/summer grazing- winter drylot herd to a year round system that utilized both spring- and fall-calving herds with weaned calves retained as stockers. Forage supplies in the year round system were derived from stockpiled forage and corn crop residues. We developed a model that randomly generated production values with parameters based on the results of a 3-year study conducted at the Iowa State University McNay Research and Demonstration farm near Chariton, Iowa. The simulated production values were combined with livestock and forage prices prevailing from 1993-2001 to estimate income per head generated by each system. Average income over the nine- year period was equal. However, the year round system was economically superior in 3 years, equivalent in 1 year, and inferior in 5 years.