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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.
11

Refinement of Release Techniques for Whitefly Parasitoids

Byrne, David N., Bellamy, David E. 10 1900 (has links)
Although they are currently effectively controlled by chemicals, sweet potato whiteflies have the potential to once again be a dominant pest in Arizona vegetables. We need to explore alternatives such as biological control so that we are not reliant solely on pesticides. We have been examining dispersal by the whitefly parasitoid Eretmocerus sp. in order to find more effective ways to deploy these agents in the field. We have learned in the laboratory that these wasps are efficient flyers since they are capable of moving into strong winds for more than 30 min. We also now know that most flight takes place within a short distance of the release point. We also have a better understanding of differences between male and female flight. This, along with other information we have obtained, will lead to our ability to effectively release these and parasitoids of other insect pests as well.
12

Potential of Particle Film Technology for Insect Management in Crisp Head Lettuce

Kerns, David L., Tellez, Tony 10 1900 (has links)
A new insect management technology known as "particle film" technology (Surround) was evaluated for it potential for control early fall pests of head lettuce in Yuma, AZ. Surround did appear to slightly reduce larval population of cabbage looper, beet armyworm and Heliothis, but not enough to be considered a commercially effective treatment. Additionally, Surround appeared to antagonize Success’s activity towards cabbage loopers. Against whiteflies, Surround did appear to reduce ovipositioning, but resultant impact on the nymph population could not be adequately assessed. Overall, Surround does not appear to have good fit in the pest management system in leafy vegetables in Yuma, AZ.
13

Implementation of a Pest Monitoring Network for Vegetable Growers in Yuma County

Palumbo, John, Kerns, David, Mullis, Clay, Reyes, Francisco 10 1900 (has links)
An insect pest monitoring network spanning the major growing areas in Yuma was implemented in 1998-1999. This project was designed to measure the relative activity and movement of adult populations during the growing season and provide important information to growers and PCA’s. A series of pheromonebaited and yellow sticky traps were placed in 11 locations among the growing areas in the Yuma, Gila and Dome Valleys in Yuma county. Numbers of adults / trap /night were recorded weekly from September-April. Seasonal differences in insect species activity and abundance among locations were observed, but difficult to precisely explain because of the lack of historical trap data. Information gathered from the trapping network will provide historical baseline data for pest activity on an area wide basis from which relationships between insect trap captures and seasonal factors that influence their activity and abundance may be explained. The results of the monitoring network during the 1998-1999 growing season for is provided in this report.
14

Identification of a small molecule inhibitor of virulence factors in multidrug resistant acinetobacter baumannii

Massey, George David Kostides 08 April 2016 (has links)
Acinetobacter baumannii is an opportunistic pathogen prevalent in nosocomial infections, most commonly infecting humans with compromised immune systems during their hospital stays. The organism's success in such circumstances has to do with its ability to survive on dry, abiotic surfaces (e.g. catheters, bed railings, and other medical equipment) and its increasingly apparent antibiotic resistance. These factors make A. baumannii a serious problem for healthcare professionals and in public health generally. A. baumannii is paradigmatic and representative of the issues confronting healthcare in the ongoing antibiotic crisis, and many strains are showing multidrug resistant (MDR) phenotypes. Given that the patients infected by A. baumannii tend to be very vulnerable and traditional antibiotic treatment seems to be getting less and less effective, it is imperative to explore alternative treatment options that may lead to better outcomes, especially if their mechanisms are not the same as the traditional antibiotics that exert the selective pressures that have led to the current antibiotic crisis. A small molecule called M64 is known to inhibit a LysR-type transcription regulator (LTTR) important for virulence, but not cell growth or viability, in another opportunistic pathogen, Pseudomonas aeruginosa. The experiments presented here show that M64 was able to rescue mice infected with A. baumannii and to downregulate the expression of important metabolic genes downstream from A. baumannii LTTRs BenM and CatM in vitro while having no effect on bacterial growth. BenM and CatM regulate genes involved in the metabolism of benzoate and catechol respectively, both of which are parts of tryptophan metabolism and are eventually broken down to form acetyl-CoA and succinyl-CoA for energy production in the citric acid cycle. Such a pharmacodynamic profile offers a starting point in the design of alternative treatments of MDR bacterial infections, as successful outcomes are observed without the direct killing of cells in vitro seen in traditional antibiotics. In this case, as catechol metabolism is important for siderophore biosynthesis and thus bacterial virulence, inhibition of the transcription of genes involved in catechol metabolism may be playing a role in the observed rescue of infected mice. Further studies are required to ascertain the nature of the inhibitor's effect, however.
15

A case study of attempts to change the range of educational alternatives in a provincial city

Ennis, Rex, n/a January 1978 (has links)
This study is an attempt to share with others, the experiences of two people who have worked to extend the range of choices in the provisions for schooling in a small provincial city. As experienced teachers as well as parents we felt that the provision of choice was essential if quality and involvement were to be increased. We were concerned both about our own children and about schooling in general. What follows is a case study of our efforts. It is a personal account of the events, the problems and the successes and failures. Although an attempt has been made to see these events clearly, to describe them as they happened, it is quite definitely written from our own point of view. In writing this account there has been a need for selectivity in regard to specific details and emphasis. The study sets out to provide sufficient detail to explain the processes involved without intruding too far into individual personalities and attitudes. Nevertheless, these events involve actual people and readers will form their own impressions. Since one of the important factors in attempts to bring about this sort of change is the personalities of the persons involved, the details are important. The writing of the study will have been worthwhile if the experiences offered here help readers gain insight into their own involvement in bringing about change or increase their awareness of the need for careful planning as well as commitment. If it poses further questions and reactions we would be delighted to hear them. Throughout the study I have used the collective "we" to signify both my wife and myself. On occasions indicated, the "we" included a variety of other people. A Chronology of Events (see Appendix A, page 64) is included since events referred to in separate chapters were occurring simultaneously. It should also be stressed that although the account ends at a certain point our activities continue.
16

The Asymptotic Distribution of the Augmented Dickey-Fuller t Test under a Generally Fractionally-Integrated Process

Chuang, Chien-Min 07 February 2004 (has links)
In this paper, we derive the asymptotic distribution of the Augmented Dickey-Fuller t Test statistics, t_{ADF}, against a generalized fractional integrated process (for example: ARFIMA(p,1+d,q) ,|d|<1/2,and p, q be positive integer) by using the propositions of Lee and Shie (2003). Then we discuss why the power decreases with the increasing lags in the same and large enough sample size T when d is unequal to 0. We also get that the estimator of the disturbance's variance, S^2, has slightly increasing bias with increasing k. Finally, we support the conclusion by the Monte Carlo experiments.
17

Goals as content-specific standards for evaluation of romantic commitment

Tennant, Patrick Solis 14 November 2013 (has links)
This thesis examines the association between the role that an individual’s partner and relationship alternatives play in his or her goal pursuits and the individual’s commitment to his or her relationship. Individual’s preference for others that aid in the achievement of his or her goals has been theoretically and empirically established (Fitzsimons & Shah, 2008). This thesis extends that work by examining the relation between multiple interpersonal dimensions of an individual’s goal pursuits and his or her romantic commitment. Rusbult’s (1980) investment model was used as a framework to develop a questionnaire that examined the degree to which an individual believed his or her partner facilitated, impeded, shared, and valued his or her goals, as well as whether the individual could accomplish the goal without his or her partner or if anyone other than his or her partner could help him or her to achieve the goal. It was hypothesized that individuals who believe that their partner facilitates and shares their goals, and that their alternative partners do not facilitate their goals, will be more committed to their relationship. These hypotheses were tested with a survey that asked participants to list three of their personal goals and rate each of them on the six interpersonal goal dimensions, as well as complete measures of relationship satisfaction, investment, alternatives, and commitment. Participants were recruited and responded to the survey through the Amazon.com Mechanical Turk marketplace. The final sample included 475 individuals that were involved in a romantic relationship at the time survey. Two structural equation models were constructed to analyze the data. Primary findings show significant associations between several of the interpersonal goal dimensions and the constructs of the investment model. Results are addressed in the context of the relevant literature, with relationship evaluation serving as the suggested mechanism. Implications and future directions are then discussed. / text
18

A case study of jail diversion : the Dekalb County Jail Diversion Treatment Court

Short, Jeffrey 05 1900 (has links)
No description available.
19

Les représentations sociales partagées par des parents d'une école alternative en regard de l'apprentissage, de l'enseignement et de la participation

Picard, Joël. January 1900 (has links)
Thèses (M.A.)--Université de Sherbrooke (Canada), 1997. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.
20

The Effects of Lag Schedules and Multiple Alternatives on Response Resurgence

Bagwell, Ashley Frances 01 August 2015 (has links)
The mitigation of response resurgence is a topic which has garnered recent attention due to its importance in a clinical setting. The present study examined the mitigation of response resurgence in a human operant study using a computer program to teach multiple response alternatives using a Lag 3 schedule of reinforcement. Of the six undergraduate students who participated in this study, three came under the control of the programmed contingencies. All three of these participants demonstrated higher rates of resurgence in the component which simulated a single response alternative when compared to the component which simulated a multiple response alternative. Areas for future study are discussed.

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