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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

Black mustard and the butterfly effect : metabolomics of plant-insect interactions under multiple stress conditions

Papazian, Stefano January 2017 (has links)
One main goal of ecological research is to understand nature´s complexity, in order to predict the potential impact of environmental perturbations. In this thesis, I investigate the ecological interactions between some of the most ancient organisms living on our planet: plants and insects. Focus of my research is the interaction between the wild brassicaceous plant black mustard (Brassica nigra L.) and its specialist insect herbivore, the large white cabbage butterfly (Pieris brassicae L). Both organisms are well characterized model species used in chemical ecology research. Using different analytical techniques, such as liquid and gas chromatography coupled to mass-spectrometry (LC- and GC-MS) and headspace collection of volatile organic compounds (VOCs), I apply the approach of metabolomics and systems biology to the field of ecology to explore the metabolic changes occurring inside the plants exposed to biotic and abiotic stresses. Particularly, I study the plant metabolic responses against P. brassicae chewing caterpillars during sequential treatment exposure to: abiotic stress by the oxidative air pollutant ozone (O3); dual herbivory with specialist Brevicoryne brassicae piercing-sucking aphids; and chemical induction of plant defences with the oxylipin phytohormone methyl-jasmonate (MeJA). Results show how during herbivore-induced responses, changes in defence- and growth-metabolic processes are tightly connected to stress protection mechanisms, indicating that plants actively reprogram their inner metabolic networks in order to adapt to consecutive changes in the environment. This thesis illustrates how evaluating the plant metabolome in its entirety rather than single metabolites, can help us understanding plant responses towards abiotic and biotic stresses, and improve our ability to predict how constant shifts in the environment affect plant physiology and ecology. / Ett huvudsyfte för ekologisk forskning är att förstå naturens komplexitet för att kunna förutse effekter av störningar i miljön. I min avhandling har jag fokuserat på ekologiska interaktioner mellan växter och insekter, två av de äldsta terrestra organismgrupperna på jorden. I mina studier har jag undersökt interaktioner mellan den korsblommiga växten svartsenap (Brassica nigra L.) och den specifika herbivoren kålfjäril (Pieris brassicae L.). Båda är väl karaktäriserade modellarter i kemisk-ekologisk forskning. De metaboliska förändringar som sker när växten utsätts för biotisk och abiotisk stress har analyserats hjälp av metabolomik, det vill säga analyser av metabolomet i sin helhet med hjälp av tekniker som vätske- och gaskromatografi kopplad till masspektrometri (LC- och GC-MS), och så kallad headspace-uppsamling av flyktiga organiska föreningar (VOCs). Jag har särskilt undersökt de metaboliska förändringar som sker när växten betas av kålfjärilslarver vid samtidig exponering för: abiotisk stress i form av ozon (O3), en oxidativ luftförorening; ytterligare betning i form av stickande och sugande bladlus (Brevicoryne brassicae); tillsats av oxylipinfytohormon metyl-jasmonat (MeJA), ett ämne som inducerar växtens försvar. Resultaten visar att de metaboliska förändringar som sker i växten vid herbivori med konsekvenser för dess försvar och tillväxt är nära kopplade till de metaboliska förändringar som sker vid stress, vilket visar att växten kan fortlöpande och aktivt omprogrammera sina metaboliska nätverk för att anpassa sig till förändringar i miljön. Avhandlingen visar att genom att utvärdera växtmetabolomet i sin helhet, snarare än att studera enskilda metaboliter, vi kan få bättre förståelse för hur växter reagerar på olika former av stress och därmed också bidra till att vi kan göra förutsägelser för hur förändringar i miljön kan påverka växters fysiologi och ekologi.
12

Odour Communication in Pieris Butterflies

Andersson, Johan January 2004 (has links)
<p>QCR 20161026</p>
13

Odour Communication in Pieris Butterflies

Andersson, Johan January 2004 (has links)
No description available.
14

Prophetic asceticism in the wilderness : dilemmas of liberation and inculturation in the interreligious paradigms of Aloysius Pieris S.J.

Bellemare, Mario. January 1998 (has links)
This work explores the interreligious paradigms proposed by Sri Lankan theologian Aloysius Pieris from a liberationist methodological standpoint. Pieris' paradigms uncover the exclusivist tendencies of some liberation theology toward 'religion' and the anti-liberative tendencies of the inculturationist school of interreligious dialogue. / The Christ-against-Religion paradigm delineates how some Latin American liberation theology constructs a sharp dichotomy between "liberative faith" and "popular religion." / The Christ-of-Religion paradigm of the Brahminic Ashram movement in India is focused on personal liberation without regard for systemic poverty and oppression. / Pieris has endeavoured to bridge the dichotomy between liberation and inculturation through what I have labelled a method of prophetic asceticism . / Using insights from feminist theology, I argue that Pieris' dialectical method subtly reactivates the oppositional Christ-against-Religion paradigm in his theology. I propose the Exodus wilderness as an intrinsic part of the liberative process and to complement Pieris' dialectics. The wilderness is a landscape of survival for God's vanquished people; a landscape of doubt that can bring forth the bread of heaven.
15

Prophetic asceticism in the wilderness : dilemmas of liberation and inculturation in the interreligious paradigms of Aloysius Pieris S.J.

Bellemare, Mario. January 1998 (has links)
No description available.
16

Differential Effects of Glucosinolate Profiles and Hydrolysis Products in Arabidopsis thaliana on Generalist and Specialist Insect Herbivores

Kemarly-Hopkins, Julie Ann 08 November 2012 (has links)
No description available.
17

Impacts of Invasive Alliaria petiolata on Two Native Pieridae Butterflies, Anthocharis midea and Pieris virginiensis

Thiemann, Danielle Marie 07 September 2017 (has links)
No description available.
18

Broccoli yield response to cabbage looper and varietal preferences of lepidopterous pests of broccoli

Vail, Karen M. January 1988 (has links)
Respondents of the 1986 Broccoli Growers Survey grew an average of 6.2 acres of broccoli in Fall 1986; popular varieties were Green Valiant (87.5% of respondents), Packman and Emperor (62.5%). Less than 5% of tobacco land was converted to broccoli production by 62.5% of the growers. Before heading, 2.4 insecticidal sprays were applied for worms at $20.51/acre. During heading, 2.4 insecticidal sprays were applied for worms at $19.40/acre. Under normal growing conditions, a nine-day mean of 8.4 and a 15-day mean of 12.1 cabbage looper larvae/plant did not significantly reduce yield in the Spring and Fall respectively. However, means of 7.4 and 11.1 cabbage looper larvae/plant reduced yield (head weight) under drought conditions. Harvest date was not affected by the above cabbage looper levels. In Fall 1986, a reduction in yield occurred when plants had 50% or more defoliation and harvest date was significantly delayed at 100% defoliation. In the drought stressed Spring 1987 planting, a stimulation in yield occurred at 25% defoliation and 75% defoliation was needed to significantly reduce yield, but there was no difference in harvest date. The imported cabbageworm was the most abundant pest of broccoli in Montgomery Co., VA. Based on counts of all immature stages of the insects for three seasons, Packman and Southern Comet varieties were less preferred compared to Green Defender. Laboratory studies indicated that imported cabbageworm larvae developed faster to the fifth instar on Packman broccoli than those reared on Green Defender, Southern Comet or Emperor. Difference in amount consumed between varieties was not detected. Pupae reared on Southern Comet weighed significantly more than those reared on Packman. / M.S.
19

Methods for protein analysis by capillary electrophoresis and mass spectrometry

Romson, Joakim January 2018 (has links)
Protein analysis is important to understanding biological systems, but sample diversity necessitates a multitude of analysis techniques and methods. Challenges that are addressed include analysis of low abundance samples, fractionation to reduce sample complexity, and automation to reduce time and cost. Matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) is an important technique for protein characterization. In Paper I, the sensitivity of MALDI-MS was enhanced through the fabrication of a hydrophobic coating for the MALDI target plate, yielding analyte concentration. The plate outperformed a commercial concentration plate. Capillary electrophoresis (CE) separation offers low sample consumption and high efficiency, and in Paper II, offline CE-MALDI-MS fractionation was employed. A robot system for automation was constructed and used in analysis of spermatophore proteins from the butterfly Pieris napi. The robot was also used in automated on-target trypsin digestion under a lid of liquid fluorocarbons, a simpler and cheaper alternative to controlled humidity chambers. An indication of indigenous proteolysis of the sample was seen. Electrospray ionization (ESI) is the other technique for protein analysis in MS. In Paper III, the biomarker protein osteopontin (OPN) was analyzed by ESI-MS in order to find suitable conditions for its detection. A preliminary optimization of solvents and ionization conditions was done, and tandem MS (MSn) performed to increase the reliability of identification. / Proteinanalys är viktigt för att förstå biologiska system, men mångfalden av prov kräver en mängd olika analystekniker och metoder. Utmaningar som tas upp inkluderar analys av små provmängder, fraktionering för att minska provkomplexiteten, och automatisering för att minska tidsåtgång och kostnad. Matris-assisterad laserjoniserings-masspektrometri (MALDI-MS) är en viktig teknik för proteinkarakterisering. I Artikel I förbättrades känsligheten i MALDI-MS genom tillverkning av en hydrofob beläggning på MALDI-provplattan, vilket gav en koncentration av provet. Provplattan gav bättre resultat än en kommersiell koncentrationsprovplatta. Kapillärelektroforesseparation (CE) har låg provåtgång och hög separationseffektivitet och i Artikel II användes offline CE-MALDI-MS-fraktionering. Ett robotsystem för automatisering konstruerades och användes för analys av spermatoforproteiner från fjärilen Pieris napi. Roboten användes även i automatiserad trypsinklyvning under en yta av en flytande fluorkolförening, ett billigare alternativ tilli nkubationskammare med kontrollerad luftfuktighet. En indikation på naturlig enzymatisk proteinklyvning i provet hittades. Elektrospray jonisering (ESI) är den andra tekniken för proteinanalys i MS. I Artikel III analyserades biomarkören osteopontin (OPN) med ESI-MS för att hitta lämpliga förhållanden för dess detektion. En preliminär optimering av lösningsmedel och jonisationsförhållanden gjordes, och tandem-MS (MSn) utfördes för att öka identifikationens tillförlitlighet. / <p>Full text will not be uploaded due to unpublished results. QC 20181121</p>
20

Pheromone production in the butterfly Pieris napi L

Murtazina, Rushana January 2014 (has links)
Aphrodisiac and anti-aphrodisiac pheromone production and composition in the green-veined white butterfly Pieris napi L. were investigated. Aphrodisiac pheromone biosynthesis had different time constraints in butterflies from the diapausing and directly developing generations. Effects of stable isotope incorporation in adult butterfly pheromone, in the nectar and flower volatiles of  host plants from labeled substrates were measured by solid phase microextraction and gas chromatography–mass spectrometry. A method to fertilize plants with stable isotopes was developed and found to be an effective method to investigate the transfer of pheromone building blocks from flowering plants to butterflies. The anti-aphrodisiac methyl salicylate was not biosynthesized from phenylalanine in flowers of Alliaria petiolata. Both aphrodisiac and anti-aphrodisiac pheromones in P.napi are produced not only from resources acquired in the larval stage, but also from nutritional resources consumed intheadult stage. Males of P. napi produce the anti-aphrodisiac pheromone from both the essential amino acid L-phenylalanine and from common flower fragrance constituents. / <p>QC 20140311</p>

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