Bovine parvovirus DNA is associated with the nuclear matrix of infected bovine fetal lung cells as shown by Southern blot analysis of matrix DNA isolated by two procedures differing in the order of exposure of detergent-treated nuclei to high salt conditions and DNase I. Protein analysis of the two matrix types showed the polypeptide composition to be similar. Both procedures showed enrichment for BPV DNA with progressive DNase I digestion. Over the course of infection the amount of BPV DNA associated with the matrix increased, yet the amount of BPV DNA associated with matrix DNA as opposed to total DNA decreased from 21% at two hours to 7% at eight hours with a subsequent rise to 13% at sixteen hours. Restriction enzyme analysis of the matrix DNA indicated that no specific portion of the BPV genome was responsible for its attachment to the matrix at the selected times. In addition both the nonstructural BPV protein, NP-1, and the capsid proteins VP1, VP2, and VP3 were associated with the matrix at sixteen hours. The association of BPV DNA and proteins with the nuclear matrix implies structural if not functional significance for the matrix in BPV replication. / M.S.

Functional programming systems provide a number of features which facilitate program verification. Such verification may be observed to rest directly upon the theoretical foundations of computing and simultaneously to exhibit a close relation to the programs being verified. In order to demonstrate these aspects of functional systems, two functions, MIN and SORT, are defined on a parameterized type consisting of sequences to elements from some ordered type. Theorems showing that MIN and SORT terminate and return the correct values are stated and proved. Similar results are derived for a function to perform a binary search on an ordered sequence. Finally, conditions similar to Dijkstra’s weakest preconditions are given which allow the simultaneous synthesis and verification of certain programs from program specifications. A function to find the greatest common division of two integers is derived and verified. / M.S.

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A hybrid method consists of a quasi-Newton method and a homotopy method for locating multiple equilibrium configurations has been proposed recently. The hybrid method combined the efficiency of a quasi-Newton method capable of locating stable and unstable equilibrium solutions with a robust homotopy method capable of tracking equilibrium paths with turning points and exploiting sparsity of the Jacobian matrix at the same time. A quasi-Newton method in conjunction with a deflation technique is proposed here as an alternative to the hybrid method. The proposed method not only exploits sparsity and symmetry, but also represents an improvement in efficiency. Limit points and nearby equilibrium solutions, either stable or unstable, can be accurately located with the use of a modified pseudoinverse based on the singular value decomposition. This pseudoinverse modification destroys the Jacobian matrix sparsity, but is invoked only rarely (at limit arid bifurcation points where the Jacobian matrix is singular). / M.S.

Vocalizations of the domestic chicken were recorded and analyzed by quantitative and qualitative methods in two experiments. In Experiment 1, recordings were made from males and females from two lines of White Leghorn chickens housed in individual battery cages. Five call types: crow, disturbance call, baaks, fear-squawks, and moans were distinguished. No significant differences were found between lines for any of the parameters measured. Crows consisted of four parts, with the combination of the durations of the various segments suggesting that they contribute to recognition among individuals. Both sexes emitted disturbance calls, baaks, fear-squawks, and moans. When comparisons were made between sexes for number of disturbance notes per second and length of fear-squawks no significant differences were found. Signal grading was shown by increased rates of disturbance notes and the addition of baaks as an individual became more upset. Three groups of eight-week old White Leghorn chickens subjected to different handling regimes emitted different vocalizations when held in the hand of the observer. Birds habituated to the handler gave mainly contentment calls while the other groups emitted peeps (distress calls), fear trills or alarm notes. A previously unreported melodic flock call was heard from White Rock chickens that were moved to a new pen at eight weeks of age. Experiment 2 consisted of comparisons between two commercial egg-laying stocks maintained under high-intensity battery cage housing. Data obtained at approximately 35 weeks of age from both stocks in the same house showed low frequencies of pecks and threats. Pullets from stock B had significantly more pushes and steps than those from stock A. The vocalizations emitted by stock B exhibited an increased range of frequencies in comparison to those by stock A. This difference was attributed to an increased number of disturbance calls and baaks and suggests that vocal behavior may be a means of assessing the social environment of chickens maintained in battery cages. / M.S.

The purpose of this research was to characterize the antibody-mediated inhibition of horseradish peroxidase activity. Inhibition of enzyme activity was determined when alternate substrates were used. Typical biphasic patterns of inhibition were observed with each of five electron donors and three hydroperoxides. In no case was inhibition complete (100%). Inhibition assays with varied substrate concentrations revealed a dependence of anticatalytic activity upon the hydroperoxide concentration. Increased hydroperoxide concentration elevated inhibition levels. Inhibition is not dependent upon the electron donor concentration. The dependence of inhibition levels on hydroperoxide concentration suggests that antibody may make the horseradish peroxidase basic isoenzyme more susceptible to peroxide inactivation. Kinetic data show increased enzyme affinity for hydrogen peroxide in the presence of antibody. In addition, acidic peroxidases that are less susceptible to peroxide are poorly inhibited by antibasic horseradish peroxidase. Spectrophotometric experiments with an electron donor analogue indicated that antibody does not inhibit horseradish peroxidase activity by preventing electron donor binding. Inhibitory antibody binding sites could not be determined because fragments of the enzyme capable of binding inhibitory antibody could not be produced. Antisera prepared against acidic horseradish peroxidase isoenzymes were used in immunological procedures (precipitation, anticatalytic assays) to assess the homology of horseradish, radish and turnip peroxidases. Acidic horseradish peroxidases with similar physicochemical properties are distinguishable by immunological methods. Interspecies relationships are stronger among acidic peroxidases than relationships between acidic and basic horseradish isoenzymes. These results support an evolutionary conservation of acidic isoenzymes and suggest that each isoenzyme group catalyzes specialized plant functions. / M.S.

An experimental investigation of the characteristics of benzene hydrogenation over nickel/kieselguhr catalyst has been made in a differential bed reactor. The study was performed at moderate temperatures (340 to 474 K), and atmospheric pressure. A Langmuir-Hinshelwood rate model assuming the Rideal-Eley mechanism for addition of molecular hydrogen to adsorbed benzene was used to describe the data. From kinetic rate data the parameters of the model were found (reproducing the experimental data to within ±10.9%). Diluting the reactant stream with nitrogen (an inert), while maintaining total pressure, temperature, and benzene mole fraction constant, linearly decreased the observed reaction rate. The diffusion-reaction characteristics of this fluid-solid system were observed by increasing the particle size, thereby forcing intraphase transport limitations to occur. Experimental effectiveness factors were compared to theoretical ones generated using the dusty gas model. Minimizing the residual sum of squares between the two yielded relationships for the effective diffusivity and the catalyst tortuosity, both of which reproduced values reported in the literature. These relationships were based on Knudsen diffusivity being the controlling diffusive mechanism, a fact shown to be true for the catalyst used in this study. / M.S.

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