• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Effects of climate on phenological synchrony between butterflies and their host plants

Posledovich, Diana January 2015 (has links)
Shifts in species’ phenologies and phenological asynchronies between the interacting organisms have received a lot of attention in the context of climate change. Changes in temporal overlap between species, caused by phenological asynchrony, make species depending on one another become so separated in time that they can no longer interact. This may have important consequences both for single species, like fluctuations in abundances, and for the functioning of whole communities by creating mismatches between trophic levels and rearrangements of community structure. This thesis focuses on the impact of temperatures on spring timing and phenological synchrony in a herbivorous insect – host plant system, consisting of the orange tipbutterfly Anthocharis cardamines and five of its Brassicaceae host plant species. Paper I demonstrates that diapause duration and winter thermal conditions can determine the timing of spring emergence in the herbivore, and these traits may differ between species with different feeding strategies. In paper II we show that thermal reaction norms of post-winterdevelopment of A. cardamines display cogradient latitudinal variation.Paper III shows that temperature-mediated phenological plasticity of A. cardamines butterflies and a majority of the most used host plant species is similar within populations originating from different latitudes. Thus, the species’ timing appeared well conserved in response to thermal variation. In paper IV we explored the importance of the butterfly’s adult emergence and thermal conditions on the succeeding part of the butterfly’s life-cycle – larval development. The outcome from the interaction was examined for both the insect and the plant side. The degree in phenological overlap between the female butterflies and host plants as well as temperatures during larval development were found to influence larval development but had no effect on plant reproductive fitness. The four papers of the presented thesis demonstrate that developmental preadaptations, evolvedin a herbivore to maintain phenological synchrony with host plants across yearly variation of spring conditions, can prevent disruption of the interaction under a wide range of temperatures. This indicates that temporary constrained interactions are not always vulnerable to decoupling, particularly if they involve generalist strategy. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Submitted.</p> / Ekoklim
2

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>

Page generated in 0.0559 seconds