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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.
1

ECOLOGY OF TRICHOGRAMMA SPP. IN THE ORD RIVER IRRIGATION AREA AND THEIR ROLE IN COTTON IPM

Davies, Andrew Paul Unknown Date (has links)
Trichogramma limit pest damage to Ord River Irrigation Area (ORIA) cotton crops by killing the developing embryo of their insect host at the egg stage, effectively reducing the number of emergent pests ingesting transgenic tissue. Their impact on the potentially resistant species, Helicoverpa armigera (Hübner), is considered integral to the Insect Resistance Management (IRM) strategy for transgenic cotton production in the ORIA. This thesis examines aspects of Trichogramma ecology pertinent to this strategy. The dominant species of egg parasitoid in ORIA cotton crops is the introduced Trichogramma pretiosum Riley. Other species make up less than one percent of collected specimens. Surveys revealed T. pretiosum has been introduced or adventitiously dispersed to all developed agricultural regions of northern Australia. Several new species were discovered during surveys in more pristine habitats. Based on field collected eggs, T. pretiosum appears to prefer H. armigera over H. punctigera Wallengren as a host in ORIA cotton. Measured as percent parasitism, Trichogramma activity appears highly variable and does not necessarily coincide with periods of peak insect pest density. Host abundance alone does not define conditions suitable for Trichogramma activity. Environmental constraints on wasp survival, such as the impact of temperature, humidity and insecticide applications, limit their effectiveness in biological control. Despite consistently high rates of percentage egg parasitism (60-99%), acceptable pest control is not readily achieved in ORIA cotton without the aid of insecticides as Helicoverpa numbers exceed damage thresholds. Insecticides inhibit Trichogramma considerably, hence the conundrum regarding initiation of insecticidal control. Trichogramma activity is relatively high early season (May to July), significantly limiting the buildup of pests. Trichogramma effectively stifle Helicoverpa population increase following initial pest egg lay at least during high density years. The impact of farming practices, especially insecticide applications, should be avoided early season to ensure pest mortality attributed to Trichogramma egg parasitisation is maximised. Pre-season habitat manipulation to establish large populations of Trichogramma in alternative hosts is advised. Despite being rare in surrounding habitats and suffering near 50% immature mortality in the field, Trichogramma effectively disperse into young crops attractive to ovipositing hosts and display a high intrinsic rate of increase. Spatial patterns of parasitism tend toward heterogeneity and do not necessarily coincide with host spatio-temporal dynamics. Both host abundance patterns and mean rates of parasitism are not good indicators of parasitoid patchiness. Parasitism rates are highest within the middle strata of the plant canopy prior to complete canopy closure despite a similar number of host eggs being available elsewhere in the plant. Pest density declines as the season progresses. However, insecticide applications become necessary if Bt expression in cotton plants wanes and larval damage increases. Measuring parasitism during periods of declining and low host density is prone to inaccuracy due to small sample size, but can be overcome with the use of egg cards. A better indication of parasitoid activity is achieved using egg cards during periods when insecticide applications are possibly required. As Trichogramma are most active in ORIA cotton from morning to early afternoon, insecticide applications if needed should occur outside of these periods. Trichogramma survival is constrained by environmental influences. Adult female T. pretiosum were exposed to ambient conditions in dialysis tubing sleeve cages to test survival and fecundity in cotton fields. Peak survival and fecundity occurs mid season with both life history variants displaying an inverse relationship to temperature. Adult female T. pretiosum survive longest in the field when provided with sustenance however mortality attributed to handling was considerable. Sleeve cages are not effective for survival measurement of small parasitoids if the cages are frequently moved. Trichogramma effectively reduce pest abundance but are clearly hindered by insecticides and hot dry conditions in ORIA cotton crops. The decision to initiate insecticide applications is best delayed unless absolutely necessary to avoid disruption of Trichogramma impact on pests. Parasitoid activity must be carefully monitored if chemical control becomes imminent. The impact of Trichogramma on pest species can then be optimally exploited.
2

Reconciliation of the Prostitute, Anchoress, and Wandering Shepherd: Coming to Terms with Self, Society, and the Divine in Thirteenth Century Iberia

Smolen, Carol Tueting January 2017 (has links)
This doctoral dissertation examines the manifestation of Christian reconciliation in three thirteenth century literary works from the Iberian Peninsula and the island of Mallorca, then part of the Crown of Aragon. This study discusses interpretations of the term “reconciliation” and applies the term to each work with regard to three aspects: reconciliation of self with self, of self with society, and of self with the divine. Chapter 1 discusses the various connotations of the term “reconciliation.” It outlines reconciliation as a synonym of penance, as in the four-steps in the Catholic Sacrament of Penance, now referred to as the Sacrament of Reconciliation. It also discusses the related Pauline concept of reconciliation and Paul’s possible sources. Chapter 2 will analyze these three aspects of reconciliation in an anonymous thirteenth century Castilian work in verse: La Vida de Santa María Egipciaca, or the Life of Santa María, the Egyptian. The prepubescent Alexandrian prostitute has an epiphany outside a church in Jerusalem, realizes the error of her ways, repents at the moment of intersection between human activity and divine intervention, and changes how she views herself, interacts with society, and regards the connection between earthly life and divinity. Chapter 3 takes a look at Gonzalo de Berceo’s cuaderna vía poem, written in Castilian about 1250 , Vida de Santa Oria, the Life of Saint Oria, through the same three lenses of reconciliation. This time the female figure is the Egyptian’s polar opposite. Oria is a young anchoress who has behaved in a saintly way mortifying the flesh since childhood. It might seem that in her case there is no need of reconciliation with herself because her virtue exceeds that of the majority of humans around her. I posit that, even in her case, there is room for acceptance of inner conflict. In addition, Oria reconciles herself to society (which admires her but tries to pull her back toward Earth against her will) and to the divine (which promises she will receive what she most desires when God deems it time). Chapter 4 studies the Romanç d’Evast e Blaquerna, a prose work in Catalan which dates from 1283-85. This early text provides an opportunity to analyze not only the protagonist’s reconciliation with self, society, and the divine but also that of an array of fictional characters including family members, his potential fiancée and the many people he meets along his journey to become a hermit. Finally, the Epilogue suggests that the idealistic notion of reconciliation has already been put to practical use in modern times in large-scale conflicts within and across borders. Coming to terms and living peaceably with differences, even grave ones, was accomplished at moments in Medieval Iberia among the three monotheistic religions: Christianity, Judaism, and Islam, and hope remains that such moments of peace will extend beyond borders and be found again today. / Spanish
3

SHARED-GM: Arquitetura de Mem´oria Distribu´ıda para o Ambiente D-GM. / SHARED-GM: DISTRIBUTED MEMORY ARCHITECTURE FOR D-GM ENVIRO

Zechlinski, Gustavo Mata 11 September 2010 (has links)
Made available in DSpace on 2016-03-22T17:26:43Z (GMT). No. of bitstreams: 1 gustavo.pdf: 2041277 bytes, checksum: 42156e7b6b140c8fd9dcda43abcba411 (MD5) Previous issue date: 2010-09-11 / The recent advances in computer technology have increased the use of computer clusters for running applications which require a large computational effort, making this practice a strong tendency. Following this tendency, the D-GM (Geometric Distributed- Machine) environment is a tool, composed by two software modules, VPE-GM (Visual Programming Environment for Geometric Machine) and VirD-GM (Virtual Distributed Geometric Machine), whose goals are the development of applications of the scientific computation applying visual programming and parallel and/or distributed execution, respectively. The core of the D-GM environment is based on the Geometric Machine (GM Model), which is an abstract machine model for parallel and/or concurrent computations, whose definitions cover the existing parallels to process executions. The main contribution of this work is the formalization and development of a distributed memory for the D-GM environment, designing, modeling and constructing the integration between such environment and a distributed shared memory (DSM) system. Therefore, it aims at obtaining a better execution dynamic with major functionality and possibly, an increase in performance in the D-GM execution applications. This integration, whose objective is to supply a shared distributed memory module to the D-GM environment, is called ShareD-GM environment. Based on the study of DSM softwares implementations, mainly on their characteristics which meet all the requirements to implement the distributed memory of the D-GM environment, this work considers the use of Terracotta system. This study highlights two facilities both present in Terracota: the portability and adaptability for distributed execution in a cluster of computers with no code modifications (codeless clustering). Besides these characteristics, one can observe that Terracotta does not make use of RMI (Remote Method Invocation) for communication among objects in a JAVA environment. From this point of view, one may also minimize the overhead of data serializations (marshalling) in network transmissions. In addition, the development of applications to evaluate the implementation of the architecture model provided by the ShareD-GM integration, as the algorithm Smith-Waterman and the Jacobi method, showed a shorter running time when compared to the previous VirD-GM execution module / O recente avanc¸o das tecnologias de computadores impulsionaram o uso de clusters de computadores para execuc¸ ao de aplicac¸ oes que exijam um grande esforc¸o computacional, tornando esta pr´atica uma forte tend encia atual. Acompanhando esta tend encia, o Ambiente D-GM (Distributed-Geometric Machine) constitui-se em uma ferramenta compreendendo dois m´odulos de software, VPE-GM (Visual Programming Environment for Geometric Machine) e VirD-GM (Virtual Distributed Geometric Machine), os quais objetivam o desenvolvimento de aplicac¸ oes da computac¸ ao cient´ıfica aplicando a programac¸ ao visual e a execuc¸ ao paralela e/ou distribu´ıda, respectivamente. O n´ucleo do Ambiente D-GM est´a fundamentado na M´aquina Geom´etrica (Geometric Machine-GM), um modelo de m´aquina abstrato para computac¸ oes paralelas e/ou concorrentes cujas definic¸ oes abrangem os paralelismos existentes para execuc¸ ao de processos. A principal contribuic¸ ao deste trabalho ´e a formalizac¸ ao e desenvolvimento de uma mem´oria distribu´ıda para o Ambiente D-GM atrav´es da concepc¸ ao, modelagem e construc¸ ao da integrac¸ ao entre o Ambiente D-GM e um sistema DSM (Distributes Shared Memory). Portanto, visando melhoria na din amica de execuc¸ ao com maior funcionalidade e, possivelmente, com melhor desempenho no ambiente D-GM. A esta integrac¸ ao, cujo objetivo ´e fornecer um modelo de mem´oria compartilhada distribu´ıda para o Ambiente D-GM, d´a-se o nome de ShareD-GM. Com base no estudo de implementac¸ oes em software de DSM e nas caracter´ısticas que atendem aos requisitos de implementac¸ ao da mem´oria distribu´ıda do Ambiente D-GM, este trabalho considera o uso do sistema Terracotta. Salientam-se duas facilidades apresentadas pelo Terracota: a portabilidade e a adaptabilidade para execuc¸ ao distribu´ıda em clusters de computadores com pouca ou at´e nenhuma modificac¸ ao no c´odigo (codeless clustering), as quais retornam grandes benef´ıcios quando da integrac¸ ao com aplicac¸ oes JAVA. Al´em disso, verifica-se o fato de que o Terracotta n ao utiliza RMI (Remote Method Invocation) para comunicac¸ ao entre os objetos em um Ambiente JAVA. Neste perspectiva, procura-se minimizar o overhead dos dados produzidos pelas serializac¸ oes (marshalling) nas transmiss oes via rede. P ode-se tamb´em comprovar durante o desenvolvimento de testes de avaliac¸ ao da implementac¸ ao da arquitetura proporcionada pela integrac¸ ao ShareD-GM, que a execuc¸ ao de aplicac¸ oes modeladas no Ambiente D-GM, como o algoritmo de Smith-Waterman e o m´etodo de Jacobi, apresentaram menor tempo de execuc¸ ao quando comparados com a implementac¸ ao anterior, no m´odulo VirD-GM de execuc¸ ao do Ambiente D-GM

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