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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Knowledge of response in thermal biofeedback training using false feedback

Haifley, Thomas D. January 1980 (has links)
This thesis has explored the effects of three variables in thermal biofeedback training using false feedback. The three controlled variables in this study are: knowledge of response for the student experimenter, and training sessions. Knowledge of response refers to the identification of a particular internal response (either GSR or skin temperature) of a subject.Although not statistically significant, results for the knowledge of response variables were found to be in the theoretically predicted direction in all conditions.
42

Screening criteria leading to the testing of the effects of Clostridium putrefariens (McBryde) on the European corn borer

Bishop, Michael J. January 1970 (has links)
The use of Clostridium species as possible pathogens of the European corn borer, Ostrinia nubilalis (Hubner) was arrived at by using screening criteria derived from studying the environment of the insect mid-gut and correlating these criteria to known physiological factors of bacteria. European corn borer larvae were treated by placing one drop of bacterial suspension on a corn borer egg mass. The newly-hatched larvae were then transferred to sterile, individual vials with synthetic food medium and observed daily. Clostridium putrefaciens (McBryde) treated larvae showed a significant reduction in hatching, slowed growth rate and a mortality of 50%.
43

The possible role of synergistic organisms acting as biological control in the European corn borer

Schwartz, Mary E. January 1972 (has links)
The effects of pathogens, used singularly or synergistically with other pathogens on the European corn borer larvae, Ostrinia nubilalis (Hubner), were studied. Pathogens used in this research were Perezia fumiferananae, Nosema disstriae, Nosema bombycis, Bacillus thuringiensis, and Beauveria bassiana. The egg masses were dipped into a vial containing a suspension of a single pathogenic species or combination of two pathogenic species. The egg masses were then incubated and hatched in a growth chamber with a temperature of 29°C, a relative humidity of 639, and constant light conditions. Observations were made concerning the mortality rates of each pathogen group.It was observed that the known pathogens, Bacillus thuringiensis, and Beauveria bassiana, caused high mortality rates in the corn borer larvae and could serve as effective biological controls. The Microsporidia, Perezia,fumiferanae, Nosema disstriae, and Nosema bombycis caused low mortality rates in corn borer larvae and therefore would not be considered as effective biological control agents for the European corn borer.The mortality rate for Bacillus thuringiensis treated larvae or Beauveria bassiana treated larvae, used in combination with other Microsporidia was not as high as when Bacillus thuringiensis,or Beauveria bassiana was used singularly. There may have been some interference or antagonism between the two combined pathogens, whether these pathogens be fungi, bacteria, or microsporidia.
44

Control of Dermestes maculatus (Coleoptera:Dermestidae) in an interior storage situation with neem, Azadirachta indica

Keeler, Cory M. January 1999 (has links)
Neem, Azadirachta indica, products were tested for toxic, growth regulating, primary antifeedant, and secondary antifeedant effects on Dermestes maculatus, under conditions approximating those found in storage facilities. Toxic and growth regulating effects were investigated using topical application of mineral oil, neem oil, purified azadirachtin/methanol solution, and 10% neem seed kernel extract/methanol solution. All neem treatments exhibited higher mortality than the mineral oil treatment 5, 10, and 14 days after the application of the treatments; larvae treated with neem products often failed to pupate and never emerged as adults. Primary antifeedant effects of azadirachtin (1.5 g/L and 5 g/L) were investigated with an original no-choice feeding bioassay. Significant primary antifeedant effects were observed which were persistent for up to 13 weeks for adults and 17 weeks for larvae. Significant secondary antifeedant effects were also demonstrated after topical application of azadirachtin (.125 g/L, .25 g/L and .5 g/L) to the larvae.
45

Endogenous resistance to insect pests in alfalfa : engineering for enhanced resistance

Mazahery-Laghab, Hojjatollah January 1997 (has links)
Alfalfa (Medicago sativa) is a valuable forage crop grown throughout the World. While the crop is resistant to attack by many insect pests, it is subject to potentially severe losses through the action of several specific pests, which are adapted to alfalfa as a host. The most economically damaging of these pests is the alfalfa weevil, Hypera postica. This thesis investigates the endogenous defences of alfalfa against insects, which are responsible for its resistance to non-pest species, and develops a strategy for increasing the resistance of alfalfa towards pest species, specifically alfalfa weevil. The role of saponins in the resistance of alfalfa towards non-pest species has been investigated by using successive insect bioassays, carried out with extracts, mixtures of compounds, and purified compounds, to identify which compounds present in alfalfa tissues are responsible for toxicity towards insects. Crude saponin extracts, in 80% methanol, from alfalfa seedling tissues were bioassayed against the cowpea seed weevil, Callosobruchus maculatus. Both extracts from shoot and root tissues caused larval mortality and delayed development when incorporated into an artificial diet at levels comparable to those found in alfalfa, but lower levels of root saponin extracts showed probiotic effects, whereas lower levels of shoot saponins were still toxic. Hydrolysis of the saponins present in these extracts decreased their toxicity. Purified saponin mixtures were prepared by butanol partition and ether precipitation, and were bioassayed against potato aphid (Aulacorthum solani) in a liquid artificial diet, which allowed quantitative effects to be accurately assayed. Shoot saponins showed a concentration-dependent toxic effect, decreasing survival over an initial 5 day period, decreasing growth, and inhibiting fecundity (measured by nymph production) in these insects. Alfalfa root saponins showed no deleterious effects below a threshold level, but caused complete mortality above this level. The alfalfa saponin mixtures were separated into fractions by chromatography on a reverse phase column. Bioassays showed that the toxicity towards potato was associated only with fractions containing saponins, and that fractions containing a component identified as soyasaponin I were more toxic to the aphids than others. Finally, two saponins purified from alfalfa, soyasaponin I and medicoside A, were assayed. These assays showed that soyasaponin was consistently more toxic in effects on mortality, growth and fecundity. It was concluded that alfalfa saponins, and in particular soyasaponin I, were major factors in the resistance of alfalfa towards potato aphid, and other insects. A saponin mixture from another species, sugar beet {Beta vulgaris) was also toxic to aphids, supporting the view that saponins have a general role in resistance to insects. Inhibition of insect digestive proteolysis by expression of a foreign protein protease inhibitor was selected as a strategy to protect transgenic alfalfa against alfalfa weevil. The major protease activity in larvae of this msect was shown to be due to cysteine proteases, which could be inhibited by cystatins. Rice cystatin was produced in large quantity using a recombinant protein expression system in E. coli for use in a "proving" experiment. Incorporation of the rice cystatin into an alfalfa weevil larvae artificial diet decreased survival, showing that this approach was feasible.
46

Enhancement of biological control with beneficial insectary plantings

Colley, Micaela Ruth 30 March 1998 (has links)
Five field experiments were conducted to evaluate the relative attractiveness of potential beneficial insectary plants to aphidophagous hover flies and parasitic Hymenoptera and the effectiveness of interplanting selected flowering plants in a broccoli field to enhance biocontrol of the cabbage aphid and green peach aphid. In 1996 we established a preliminary screening trial to begin development of our sampling methods and evaluations of the attractiveness of selected flowering plants to hover flies and parasitic Hymenoptera. In 1997, we conducted a field experiment at the Oregon State University Vegetable Research Farm near Corvallis, OR to assess the relative attractiveness of 11 selected flowering plants to hover flies and parasitic Hymenoptera. Six of these plants were also evaluated for attractiveness to aphidophagous hover flies in two on-farm trials. The experimental design was a complete randomized block design, with four replications at the OSU site, and three replications at the two on-farm sites. Attractiveness of flowering plants to hover flies was assessed by conducting weekly timed observations of feeding frequencies. Associations of parasitic Hymenoptera were assessed by weekly timed vacuum sampling from a fixed area in plots of flowering plants. Attractiveness differed by dates and sites. Among early-season flowering species, Coriandrum sativa (cilantro) was highly attractive to aphidophagous hover flies and Brassica juncea (mustard), Fagopyrum esculentum (buckwheat) and Agastache rugosa (Korean licorice mint) were most attractive to parasitic Hymenoptera. Among late-season flowers, Achillea millefolium (yarrow), Foeniculum vulgare (fennel) and Agastache rugosa (Korean licorice mint) were most attractive to hover flies, but attractiveness to parasitic Hymenoptera did not differ. An on-farm trial was conducted in 1997 at Stahlbush Island Farm near Corvallis, OR. The objective of this trial was to test the hypothesis that interplanting either alyssum (Lobularia maritima), or cilantro (Coriandrum sativa), with broccoli (Brassica oleracea) would attract aphidophagous hover fly adults and parasitic Hymenoptera, enhance oviposition in the adjacent crop, and increase larval predation and parasitism in the adjacent crop, resulting in suppressed cabbage aphid (Brevicoryne brassicae) and green peach aphid (Myzus persicae) populations in the broccoli crop. The predominate hover fly species present were Toxomerus occidentalis and T. marginatus. More adult female T. occidentalis were caught in pan traps in plots with alyssum than in cilantro or control plots. More hover fly eggs were found on broccoli leaves and a higher percent of the aphids present were parasitized by Hymenoptera in plots with alyssum than in cilantro or control plots. However, no differences in aphid intensities were found between treatment and control plots. A comparison between the mean number of hover fly eggs found per broccoli leaf and the mean number of aphid counted per broccoli leaf suggests there is an association between the two. There appears to be an aphid density threshold below which few hover fly eggs are laid. Gravid females were present in the crop from the first sampling date on, yet hover fly eggs were not found in the crop until the second to last sampling date. Our results indicate that the presence of alyssum enhanced hover fly activity, but did not result in increased larval predation on aphids in the crop. In 1997 a survey of hover flies was conducted at each of the four experimental sites. Hover flies were captured with sweep nets. Representative specimens were identified to species by Christian Kassebeer, University of Kiel, Germany and subsequent identifications were made from reference specimens and with taxonomic keys. Twenty species were identified, 16 of which are aphidophagous. At the OSU site and the two on-farm sites, where the relative attractiveness of flowering plants was assessed, the six most common aphidophagous species, collected at all three sites, were: Meliscaeva cinctella, Toxomerus marginatus, T. occidentalis, Sphaerophoria sulphuripes, S. pyrrhina, and Scaeva pyrastri. / Graduation date: 1998
47

Developing a bioinformatics utility belt to eliminate search redundancy from the ever-growing databases

Taylor, Misha. Engelen, Robert A. van. January 2003 (has links)
Thesis (M.S.)--Florida State University, 2003. / Advisor: Dr. Robert van Engelen, Florida State University, College of Arts and Sciences, Department of Computer Science. Title and description from dissertation home page (viewed Oct. 1, 2003). Includes bibliographical references.
48

Modeling, identification and control of a dynamic and stochastic chemical biological process

Adeyemi, Suleyman Olatunji, January 1976 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1976. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 358-372).
49

Field and laboratory trials in Mali to determine the effects of neem extracts on three millet pests, Heliocheilus albipunctella De Joannis (Lepidoptera: Noctuidae), Coniesta ignefusalis Hampson (Lepidoptera: Pyralidae) and Kraussaria angulifera Krauss (Orthoptera: Acrididae)

Passerini, Julien January 1991 (has links)
Formulations of aqueous neem extracts were sprayed in field experiments. Results showed that a 0.5% and 1% concentrations were effective in reducing grasshopper feeding and diminishing damage caused by the millet stemborer, C. ignefusalis. In 1988, neem diminished egg-laying and mine damage by the headminer, H. albipunctella, but no data were available for 1989 because of the low infestation levels of this pest. / Neem exhibited some systemic activity. Soil applied neem kernel powder partially protected millet against K. angulifera and C. ignefusalis. Neem treated plots yielded more grain and suffered less damage by insect pests than four different cultural practices. Only the addition of fertilizer was superior to neem in reducing yield losses but it was inferior in limiting pest losses. / Experiments to test the residual activity of neem showed that this botanical insecticide can effectively protect millet against K. angulifera for at least seven days, and possibly longer if ultra-violet rays and rainfall are not prevalent. Analysis of plant selection behavior of K. angulifera showed that neem is an antifeedant rather than a repellent. On first to third instar nymphs, growth regulating activity expressed as a difficulty in molting or an absence of sclerotization may occur. Topical applications of neem to the stemborer, C. ignefusalis, also caused growth abnormalities, mostly molting disturbances. Treated larvae that reached the adult stage were malformed. / This research indicates that neem based insecticides offer considerable promise for Sahelian farmers for protecting millet crops. It is effective against K. angulifera, but less effective against the stemborer, C. ignefusalis. Although the data obtained for H. albipunctella in 1988 was promising, it was insufficient to reach any conclusions regarding neem's efficacy with respect to this pest.
50

Electromyograph biofeedback and the treatment of chronic low back pain

Bush, Clarissa. January 1984 (has links)
Sixty-six chronic low back pain sufferers, recruited through the media, were randomly divided into three groups. Following an assessment consisting of psychological questionnaires, pain monitoring and measurement of paraspinal electromyogram (EMG), one group received paraspinal EMG biofeedback, and a second group received a placebo treatment. The third group received no intervention. Two further assessments were carried out on all groups immediately after and three months after treatment. All groups showed significant reductions in pain, anxiety, depression and paraspinal EMG, but there were no differences among the groups. A regression analysis failed to identify subject characteristics which predicted positive outcome in the biofeedback group, but the Evaluative scale of the MPQ and hypnotizability were significant predictors of outcome for the placebo group. The results are discussed in terms of a general placebo effect of participating in research designed to reduce pain. It is concluded that paraspinal EMG biofeedback is not an effective treatment for chronic low back pain in a non-hospitalized population.

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