The interactions of paraquat (methylviologen) and diphenylether herbicides with the Mehler reaction as investigated. Sera from two different rabbits (RS1 & RS2) were examined for their patterns of inhibition of the photosynthetic electron transport (PET) system. Serum from RS2 was greatly hemolyzed. Fifty ul of RS1 serum were required for 100% inhibition of a H₂O → methylviologen(MV)/O₂ reaction, whereas only 10 µl of a 1:10 dilution of RS2 were needed for 100% inhibition. The γ-globulin fraction from purified rabbit serum (RS1) did not inhibit PET, indicating that the antibody fraction of the rabbit serum does not contain the inhibitor. It appears that the inhibitor is from the hemolyzed red blood cells. Rabbit sera, added to chloroplast preparations prior illumination, caused no inhibition of a H₂O → MV/O₂ reaction while addition of rabbit sera during illumination inhibited the H₂O → MV/O₂ reaction within 1-3 s. Various Hill reactions were used to determine the site of inhibition. Rabbit sera inhibited photosystem I (PSI) Hill reactions, but did not inhibit a photosystem II (PSI II) Hill reaction indicating that inhibition is on the reducing side of PSI. It would be expected that a H₂O → Ferredoxin (Fd)/NADP Hill reaction should also be blocked. Surprisingly, rabbit sera did not inhibit this reaction. These results were interpreted as supportive evidence for parallel (branched) electron transport on the reducing side of PSI. Six pyridyl derivatives {benzylviologen, 2-anilinopyridine, 1,2-bis(4-pyridyl)ethane, 1,2-bis(4-pyridyl)ethylene, 2-benzoylpyridine, and 2-benzylaminopyridine} and five heme-iron derivatives {hemoglobin, hemin, hematin, ferritin, and ferrocene} were screened for their potential to counteract paraquat toxicity on pea (Pisum sativum L. cv. Little Marvel) isolated chloroplasts. H₂O → MV/O₂ and H₂O → Fd/NADP+ were the two Hill reactions assayed with these compounds. Antagonists of paraquat toxicity should inhibit the first Hill reaction but not the latter. None of the pyridyl derivatives examined inhibited the reaction H₂O → MV/O₂. Ferritin and ferrocene were also ineffective as inhibitors of this reaction. Hemoglobin inhibited the reaction H₂O → MV/O₂ without inhibiting the reaction H₂O → Fd/NADP+, providing protection to pea chloroplasts against paraquat. Hemin and hematin inhibited both Hill reactions examined. Hemin and hematin also inhibited H₂O → diaminodurene (ox) and durohydroquinone → MV/O₂ Hill reactions but not the dichlorophenylindolphenol(red) → MV/O₂ and diaminodurene(red) → MV/O₂ Hill reactions. These results indicate that hemin and hematin are inhibiting photosynthetic electron transport in the plastoquinone pool region. Potential involvement of hydroxyl and alkoxyl radicals in the peroxidative action of the p-nitro diphenyl ether herbicides acifluorfen was evaluated under laboratory conditions. Methional was added to illuminated pea thylakoids and its oxidation to ethylene was used as an indicator of hydroxyl and alkoxyl radical synthesis. Oxyfluorfenstimulation of the rate of methional oxidation was dependent on light, photosynthetic electron transport and hydrogen peroxide since it was not observed under dark conditions or in the presence of DCMU and catalase. Addition of FeEDTA, a catalyst of the Fenton reaction, stimulated the oxyfluorfen-induced enhancement of methional oxidation six-fold suggesting that hydroxyl radicals are synthesized through a Fenton reaction. Acifluorfen, nitrofen and nitrofluorfen inhibited the rate of methional oxidation whereas, acifluorfen-methyl had no effect on the rate of methional oxidation even at high concentrations (1 mM). Nitrofluorfen at 1 mM was the only p-nitro diphenyl ether herbicide tested which inhibited photosynthetic electron transport of pea thylakoids. In experiments with pea leaf discs, acifluorfen at low concentrations stimulated the rate of methional oxidation, while acifluorfen-methyl, nitrofen and nitrofluorfen had no effect. These data indicate that hydroxyl and alkoxyl radicals could be involved in the mechanism of cellular damage caused by oxyfluorfen, but they are not important for the activity of the diphenyl ether herbicides acifluorfen, acifluorfen-methyl, nitrofen, and nitrofluorfen. Diethyldithiocarbamate (DEDTC) does not accept electrons from the photosynthetic electron transport (PET), but can donate electrons to a photosystem I (PSI) Mehler reaction in the presence of the following PET inhibitors: diuron, dibromothymoquinone, and bathophenanthroline. It cannot photoreduce PSI in the presence of cyanide, a PET inhibitor. These data indicate that the site of electron donation is after the plastoquinone pool. Ascorbate is not required for the ability of DEDTC to donate electrons to PSI. There is no photoreductant activity by DEDTC in a ferredoxin/NADP Hill reaction. Superoxide dismutase inhibits DEDTC/diuron or bathophenanthroline → MV/O₂ Mehler reaction. Catalase does not restore the consumed O₂ from a DEDTC/diuron → MV/O₂ Mehler reaction, indicating O₂- has not been dissmutating into H₂O₂. These results indicate that superoxide is required for DEDTC ability to donate electrons, therefore DEDTC is limited only to Mehler-type reactions. / Ph. D.

Research in the area of multimedia instruction has yielded results that indicate that learning is better when verbal information is presented auditorily instead of visually (i.e. modality effect) and when redundant on-screen text is removed from the instructional environment (i.e. redundancy effect). The present study aimed to extend these findings by exploring the effects of presentation modality and redundancy of verbal information on students' ability to apply and recall a historical inquiry strategy. Fifty-six students were randomly assigned to three treatment groups, which differed according to the presentation mode combination used to present the strategy instruction. Specifically, students received the instruction either as animation and narration, animation and text, or animation, narration, and text. The students were engaged in a multimedia strategy intervention for a total of five days, for approximately 25 minutes a day. Three strategy application tests (i.e., pre-test, post-test, maintenance test) and a recall test were used to measure the students' learning. Data attained through the strategy application tests and recall tests were analyzed using Analysis of Variance (ANOVA) procedures. The results of the study revealed significant differences in the training main effects analysis indicating that strategy instruction can be effectively provided in a multimedia learning environment. However, no significant differences were found for the modality and redundancy main effects indicating that there was no difference in strategy application or recall between the groups. Although the results did not provide the statistical significance that supports the literature on the modality and redundancy effects, the implications of the findings of the research provide several viable areas for future research. / Ph. D.

As was stated before, the purpose of this problem was to find out the effect of freezing on mortar at different hours after mixing. This was a continuation of the work done by G.H. Harris in 1945. It was hoped that by using different materials, steel molds, and by molding, freezing and testing the specimens as accurately as was possible to do so with the equipment available the peculiar results obtained by Harris could either be verified or disproved. The results obtained by this problem were very irregular but did show a slight trend and did not show the great difference in strength over a short period of time as was shown by Harris’s results. To get a definite answer a large number of samples should be run for each different time of set before freezing. A large variety of materials should be used and it is also believed that test cylinders 6”x12” would give better results. / Master of Science

This bachelor thesis investigates nitrogen and carbon stable isotopes in Ireland during the Mesolithic and Neolithic. In recent years, the understanding of subsistence strategies in Northwestern Europe has improved and it has shown that the dietary stable isotope data of Neolithic Ireland is an extreme outlier in the region. The aim is to examine the manuring and canopy effect that have often been suggested to be possible contributing factors for this difference. There is no certainty whether this difference is due to diet, land use or any other cause while these effects remain uninvestigated. The effects are studied by comparing dietary isotopes with sources about land use, such as pollen and geochemical data, for four sites: Carrowkeel, Poulnabrone, Knowth and the Mound of Hostages (Duma na nGiall), which together comprise c. 80% of the Neolithic Irish stable isotope record. The manuring effect is not visible in the current stable isotope, pollen, geochemical, zoological and archaeobotanical record. The canopy effect may be reflected in that same dataset. If the canopy effect is indeed the cause of the difference between Irish and Southern British δ13C values, a detailed comparison between the pollen data close to the origin of the carbon stable isotope samples and the carbon stable isotope samples in another area, such as Southern Britain, may explain the outlier position of Ireland in North-western Europe. / Denna C-uppsats undersöker kväve-och kolisotoper i det neolitiska och mesolitiska Irland. Genom en stor tillväxt av data har det blivit tydligt att de irländska kväve- och kolvärdena är extrema jämfört med resten av britannien. Gödslingseffekten och trädskiktseffekten är två effekter som har misstänkts att orsaka denna skillnad. Syftet är att undersöka dessa effekter genom att leta efter samband mellan markbruk och stabila isotoper. Fyra begravningsplatser har valts ut till detta syfte: Knowth, Carrowkeel, Poulnabrone och Duma na nGiall (Mound of Hostages). 80% av alla stabila kol- och kväveisotopvärden härstammar från dessa begravningsplatser. Gödslingseffekten gick inte att identifiera i datasamlingen som innehåller stabila isotopvärden, pollen, zoologisk data, arkeobotanisk och geokemisk data. Trädskiktseffekten möjligtvis bekräftas av datasammanställningen. För att kunna förklara den fullständiga skillnaden mellan syd-brittiska och irländska δ13C-värden behövs en studie som även inkluderar detaljerad data av neolitiskt markbruk från Brittiska ön.

Typescript (photocopy) / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript, etc. / Digitized by Kansas State University Libraries

Call number: LD2668 .T4 1929 M63

LD2668 .T4 1954 G6 / Master of Science