Academic literature on the topic 'LD5655.V856 1984.T444'

The carbon monoxide dehydrogenase complex was purified from acetate-grown Methanosarcina thermophila. This complex made up greater than 10% of the cellular protein and the native enzyme formed aggregates with a Mr of approximately 1,000,000. The enzyme contained five subunits of different molecular weight suggesting a multifunctional enzyme complex. Nickel, iron, cobalt, zinc, inorganic sulfide, and a corrinoid were present in the complex. The electron paramagnetic resonance spectrum of CO-reduced enzyme at 113K contained g values of 2.073, 2.049, and 2.028. Isotopic substitution with ⁶¹Ni, ⁵⁷Fe, or ¹³Co resulted in broadening of the spectrum consistent with a Ni-Fe-C spin-coupled complex. Acetyl-CoA caused a perturbation of the signal that was not caused by acetyl-phosphate or mercaptoethanol indicating acetyl-CoA is a physiological substrate. Cell extracts from acetate-grown M. thermophila contained CO-oxidizing:H₂-evolving activity 16-fold greater than extracts of methanol-grown cells. CO-oxidizing:H₂-evolving activity was reconstituted upon combination of: (i) CO dehydrogenase complex, (ii) a ferredoxin, and (iii) purified membranes with associated hydrogenase and b-type cytochrome. The ferredoxin was a direct electron acceptor for the CO dehydrogenase complex. The molecular weight of the isolated protein was 16,400, and the apparent minimum molecular weight was 4,900. The ferredoxin contained 2.8 ± 0.56 Fe atoms and 1.98 ± 0.12 acid-labile sulfide. UV-visible absorption maxima were 395 and 295 nm with a A₃₉₅/A₂₉₅ ratio range of 0.80 to 0.88. The N-terminal amino acid sequence revealed a 4-cysteine cluster, similar to other Fe:S centers that coordinate a Fe:S center. A CH₃-B₁₂:HS-CoM methyltransferase activity was characterized in extracts of acetate- and methanol-grown cells. The activity from extracts of acetate-grown M. thermophila was stable at 70°C for 30 minutes. The activity in cell extracts of acetate- and methanol-grown cells was fractionated with ammonium sulfate treatment and FPLC phenyl superose chromatography. Two peaks of methyltransferase activity were observed in each cell extract sample following phenyl superose fractionation.
Ph. D.

Agricultural production in France has increased considerably since the late fifties, turning France into a net exporter in world markets. This has generated a heated policy debate between France and the United States, centering around different views of the sources of growth in French agricultural production between 1960 and 1984. To shed some light on this debate, these sources of growth were analyzed. A sectoral model of the French agricultural sector is developed. It is based on the assumption of profit maximization. Duality theory is used to derive short- and long-run output supply and input demand equations. All variables controlled by the decision-maker are endogenized. These include output supplies (cereals, other crop products, milk, other animal products), use of variable inputs (feeds, fertilizer-energy, hired labor), and optimal quantities of the quasi-fixed factors (family labor, capital). The data used in estimation comes from published sources, except for series concerning French agricultural research expenditures, preferential credit rates, and agricultural labor. These were collected from unpublished sources specifically for the study. In general, signs of estimated coefficients conform to theoretical expectations. Technological change is estimated to have played the major role in inducing production growth. Technology-led increases are attributed mostly to French research expenditures in the case of cereals, and, in the case of milk, both to French research expenditures and to transfers of technology. Credit policies have also played a role, being responsible for an estimated 8.6 and 10.4 percent of the growth in cereals and milk production. These results have important policy implications. First, if rapid technological gains have brought France into a situation of comparative advantage, we should expect to see French policy-makers shift toward a freer market stance in trade negotiations. Second, because of massive technology transfers and shrinking export markets, the problem of protection of national research is likely to become a part of trade policy debates. Third, even if international negotiations succeeded at reducing price supports, such steps could be quickly outweighed by continual outward shifts of the supply curves if efforts to develop agricultural technology are pursued.
Ph. D.

The primary purpose of this study was to investigate (1) the degree of compliance by PHBCU in meeting the white student enrollment standards in the Adams States that took place between 1976-1984; (2) the implementation of Adams v Richardson between 1976-1984 based on the enrollment of white students at PHBCU; and (3) the implementation of Adams v Richardson as determined by mandated State plans between 1976-1984. Data were generated from two principal sources. They were: 1. State plans for complying with the Adams decision. 2. Refined HEGIS enrollment data by race and level of instruction. Results can be summarized as follows: (1) The PHBCUs varied widely in their reports of compliance. They implemented a variety of strategies to recruit white students. The form and pattern used varied considerably from one campus to another. (2) Nonetheless, the percent of overall white enrollment in the 25 PHBCUs increased from 6,729 or 7.3% of total PHBCU enrollment in 1976 to 8,119 or 9.6% of total enrollment in 1984, an increase in those years of about 20% (Table 23). (3) At the same time, white student enrollment in all classes of principally black institutions in the ten Adams states increased from 13,108 students in 1976 to 18,547 in 1984, an increase of 42% during this period (Table 15). (4) Similarly, white student enrollment increased by about 41% in all classes of principally black institutions nationwide during this same period (Table 5). (5) Accordingly, whatever benefits from the Adams decision that may have accrued to the PHBCU seem to have been accelerated in other classes of black institutions. (6) The evidence from this study does not support the conclusion that the Adams decision materially improved or enhanced the planning process in the PHBCUs. It may well have done so, but the evidence is not forthcoming from this study to support any firm conclusion in that regard. (7) What seems clear, however, is that the Adams decision drew positive attention to a need for institutional and statewide planning in all classes of black institutions, particularly in the Adams states, and to the need for systematic development of information, and for conscientious monitoring and assessment of results. It would appear that all classes of black institutions, not solely the PHBCU targeted by the Adams decision, were attentive to the message conveyed by the decision.
Ed. D.

The study surveyed two groups of elementary school principals who participated in the 1983 and 1984 NAESP National Fellows Program by means of a questionnaire; one hundred seventy-three principals from the 1983 program and one hundred twenty-six from the 1984 group. The questionnaire sought to gather information in an effort to determine whether the subjects made changes in their schools in five selected categories during the 1983-1984 school year, and if so, the sources the subjects cited as motivating them to undertake such a change. The information indicated that the highest number of respondents (N=238) reported making changes or undertaking new initiatives in their instructional programs with a seventy-nine (79%) response in this category. There were differences between the two groups in two categories: creating business/school partnerships and management style. There was relatively little difference between the two groups in the final two categories: use of technology to provide information to students and marketing the good things about school. The investigator concluded that (1) the principal does influence change in the school and the instructional program of the school receives the greatest level of involvement from the principal; and, (2) that the information provided by the principals indicated that conventions, books, and contact with other colleagues provided the most frequently cited sources for motivation to undertake change or new initiatives; and, (3) that participation in the NAESP National Fellows Program could be considered a strong motivating force for impacting change in the schools led by the participants.
Ed. D.
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