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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

A genetic approach to the study of abscisic acid biosynthesis

Linforth, R. January 1986 (has links)
No description available.
2

Molecular and Physiological Characterization of the Flowering Time Control Protein, HvFCA and its Role in ABA Signalling and Seed Germination

Kumar, Santosh 07 April 2010 (has links)
The RNA binding protein Flowering Time Control Locus A (FCA) regulates flowering in rice and Arabidopsis. The abscisic acid binding protein ABAP1 shares high sequence homology to FCA and was considered the FCA homologue in barley. The current study investigates the existence of ABAP1 as an independent gene product and also the cloning, characterization and functional significance of the gamma (γ) isoform of FCA from barley. Barley FCA protein showed higher sequence similarity to wheat and rice FCA compared to Arabidopsis FCA. It contains two RNA recognition motifs (RRMs), a glycine rich region at the N-terminal end, the WW domain and a poly-glutamine region immediately downstream of WW domain at the C-terminal. In developing barley embryos, FCA transcripts could be detected from 2 days after pollination (DAP) up to late maturity without any detectable change within these stages. FCA transcript levels declined as germination progressed in barley embryos and the FCA transcripts were retained for longer duration when germination was reduced with application of ABA. FCA also showed up-regulation by ABA and abiotic stresses in barley germinating seeds and seedlings. Transient co-expression of barley FCA or a truncated FCA (lacking RRM) with a maize VP1 promoter-GUS construct or a wheat Em gene promoter-GUS construct in barley aleurone layer protoplasts led to increased GUS activity in both cases. Adding ABA during the incubation enhanced the observed increase due to FCA expression. Similar effects of transient over-expression of FCA in barley embryos affected VP1. Barley FCA localized to the nucleus. This nuclear localization was due to the nuclear localization signal within the protein and not due to the RNA recognition motifs (RRMs) as the truncated FCA lacking RRMs also localized to the nucleus. Barley FCA did not restore the flowering phenotype in an Arabidopsis fca-1 mutant. In conclusion, I have shown that barley FCA is up-regulated by ABA and stress in embryos and affects ABA signalling in barley caryopses. The properties of FCA appear to have diverged between dicot and monocot systems.
3

Molecular and Physiological Characterization of the Flowering Time Control Protein, HvFCA and its Role in ABA Signalling and Seed Germination

Kumar, Santosh 07 April 2010 (has links)
The RNA binding protein Flowering Time Control Locus A (FCA) regulates flowering in rice and Arabidopsis. The abscisic acid binding protein ABAP1 shares high sequence homology to FCA and was considered the FCA homologue in barley. The current study investigates the existence of ABAP1 as an independent gene product and also the cloning, characterization and functional significance of the gamma (γ) isoform of FCA from barley. Barley FCA protein showed higher sequence similarity to wheat and rice FCA compared to Arabidopsis FCA. It contains two RNA recognition motifs (RRMs), a glycine rich region at the N-terminal end, the WW domain and a poly-glutamine region immediately downstream of WW domain at the C-terminal. In developing barley embryos, FCA transcripts could be detected from 2 days after pollination (DAP) up to late maturity without any detectable change within these stages. FCA transcript levels declined as germination progressed in barley embryos and the FCA transcripts were retained for longer duration when germination was reduced with application of ABA. FCA also showed up-regulation by ABA and abiotic stresses in barley germinating seeds and seedlings. Transient co-expression of barley FCA or a truncated FCA (lacking RRM) with a maize VP1 promoter-GUS construct or a wheat Em gene promoter-GUS construct in barley aleurone layer protoplasts led to increased GUS activity in both cases. Adding ABA during the incubation enhanced the observed increase due to FCA expression. Similar effects of transient over-expression of FCA in barley embryos affected VP1. Barley FCA localized to the nucleus. This nuclear localization was due to the nuclear localization signal within the protein and not due to the RNA recognition motifs (RRMs) as the truncated FCA lacking RRMs also localized to the nucleus. Barley FCA did not restore the flowering phenotype in an Arabidopsis fca-1 mutant. In conclusion, I have shown that barley FCA is up-regulated by ABA and stress in embryos and affects ABA signalling in barley caryopses. The properties of FCA appear to have diverged between dicot and monocot systems.
4

Vliv teploty na maturaci a desikaci somatických embryí smrku

Vavřičková, Marika January 2010 (has links)
No description available.
5

Identification of abscisic acid-binding proteins using a bioactive photoaffinity probe

Galka, Marek Michal 15 September 2009
This project was expected to contribute to the understanding of abscisic acid (ABA) perception in plants through identification of new ABA-binding proteins. The novel, biotinylated ABA derivative PBI686 (of biological activity comparable to natural ABA) has served as an affinity probe for isolation of ABA-binding proteins. Photoaffinity labeling in conjunction with affinity chromatography (streptavidin-biotin based) was used for specific identification of target proteins from complex mixtures of cytosolic and membrane-bound proteins. Proteins of interest were identified by Mass Spectrometry through peptide mass fingerprinting and MS/MS ion search.<p> Ribulose bisphosphate carboxylase/oxygenase (Rubisco) was identified as an ABA binding partner, and its interaction with ABA was initially confirmed by its ability to block the photoaffinity labeling reaction with PBI686. In addition, Surface Plasmon Resonance (SPR) experiments with ABA and Rubisco were performed, which provided further evidence for selective interaction between the two binding partners, with a very small preference towards (+)-ABA over (-)-ABA. SPR has also yielded the value of equilibrium dissociation constant (KD) being 5 nM for (+)-ABA and 7 nM for (-)-ABA. This was further confirmed by [3H] (±)-ABA binding assays, which have also shown that non-radiolabeled (+)-ABA and (-)-ABA (at concentration 1000 fold higher) were able to displace [3H] (±)-ABA from binding to Rubisco. Compounds other than ABA such as PA (phaseic acid) or trans-(+)-ABA were not able to displace [3H] (±)-ABA, which has suggested the selectivity of binding. Further, Rubisco enzymatic activity in the absence of ABA was compared to that in the presence of ABA at various concentrations. The results have clearly indicated the effect of ABA on Rubiscos enzymatic activity. This was reflected on the enzymes Km values being increased by seven fold in the presence of 10 mM ABA and 1 mM substrate (RuBP). The interpretation of changes in enzyme kinetics upon inhibition by ABA most resembles allosteric inhibition. The biological function of this newly discovered interaction is interpreted as ABAs ability to regulate plant growth during abiotic stress by its direct action on the photosynthetic machinery - hypothesis often suggested in the literature.
6

Identification of abscisic acid-binding proteins using a bioactive photoaffinity probe

Galka, Marek Michal 15 September 2009 (has links)
This project was expected to contribute to the understanding of abscisic acid (ABA) perception in plants through identification of new ABA-binding proteins. The novel, biotinylated ABA derivative PBI686 (of biological activity comparable to natural ABA) has served as an affinity probe for isolation of ABA-binding proteins. Photoaffinity labeling in conjunction with affinity chromatography (streptavidin-biotin based) was used for specific identification of target proteins from complex mixtures of cytosolic and membrane-bound proteins. Proteins of interest were identified by Mass Spectrometry through peptide mass fingerprinting and MS/MS ion search.<p> Ribulose bisphosphate carboxylase/oxygenase (Rubisco) was identified as an ABA binding partner, and its interaction with ABA was initially confirmed by its ability to block the photoaffinity labeling reaction with PBI686. In addition, Surface Plasmon Resonance (SPR) experiments with ABA and Rubisco were performed, which provided further evidence for selective interaction between the two binding partners, with a very small preference towards (+)-ABA over (-)-ABA. SPR has also yielded the value of equilibrium dissociation constant (KD) being 5 nM for (+)-ABA and 7 nM for (-)-ABA. This was further confirmed by [3H] (±)-ABA binding assays, which have also shown that non-radiolabeled (+)-ABA and (-)-ABA (at concentration 1000 fold higher) were able to displace [3H] (±)-ABA from binding to Rubisco. Compounds other than ABA such as PA (phaseic acid) or trans-(+)-ABA were not able to displace [3H] (±)-ABA, which has suggested the selectivity of binding. Further, Rubisco enzymatic activity in the absence of ABA was compared to that in the presence of ABA at various concentrations. The results have clearly indicated the effect of ABA on Rubiscos enzymatic activity. This was reflected on the enzymes Km values being increased by seven fold in the presence of 10 mM ABA and 1 mM substrate (RuBP). The interpretation of changes in enzyme kinetics upon inhibition by ABA most resembles allosteric inhibition. The biological function of this newly discovered interaction is interpreted as ABAs ability to regulate plant growth during abiotic stress by its direct action on the photosynthetic machinery - hypothesis often suggested in the literature.
7

Brain connectivity changes associated with one year of behavioral therapy for young children with autism spectrum disorder (ASD)

Ormand, Hailey Michelle 10 December 2013 (has links)
Although much of the current literature in autism spectrum disorders (ASD) has focused on illuminating their biological underpinnings or identifying effective treatment approaches, very little research has integrated these two areas of study and examined the neurobiological outcomes associated with various autism interventions. The proposed study will use functional connectivity magnetic resonance imaging (fcMRI) to measure changes in resting state connectivity associated with an intensive behavioral intervention for young children with ASD. Independent component analysis and t-tests will be used to determine if 20 children receiving a behavioral intervention experience greater changes in connectivity than 20 children (matched for sex and developmental age) in a control group receiving treatment as usual (TAU). / text
8

Parental perspectives on social support needed during their child's transition from preschool to school within an early intensive behavioural intervention program

Khanas, Yulia 20 January 2014 (has links)
The purpose of this study was to examine the experiences of parents of children with autism during the transition from preschool to school within an Early Intensive Behavioural Intervention (EIBI) program. Qualitative interviews within grounded theory framework were conducted to gain a better understanding about parents’ perceptions of the social supports they received during the transition period. Data collection involved semi-structural interviews with six families whose children completed EIBI program at St.Amant and were enrolled in school. Due to the small sample size, a metasynthesis of five qualitative studies about the transition experiences of families with children with autism was added. This metasynthesis provided additional information to the data collected from interviews in order to strengthen the trustworthiness of the current study. All data collected from the interviews were coded, categorized and analysed using a constant comparative method. Findings from both data collection components emphasize the importance of parents’ involvement in the transition process and suggest that an effective partnership between the home, the EIBI program and the school is a significant factor to a successful transition. The findings also highlight the need for strategic planning of the transition process that is family-focused and involves an active role of a facilitator, who can offer practical guidance and support to children and their families. Practical implications and recommendations for future research are discussed.
9

Commercializing a microfinance institution to maximize profit : (A study of the Sinapi Aba Microfinance Institution-Ghana)

Allotey, Daniel January 2008 (has links)
<p>ABSTRACT</p><p>Date: 2008-06-23</p><p>Level: Bachelor Thesis in Business Administration, Basic Level 300, 15 ECTS-Points</p><p>Author: Daniel Allotey</p><p>Tutor: Per Nordqvist</p><p>Title: Commercializing a microfinance institution to maximize profit</p><p>(A study of the Sinapi Aba Microfinance Institution-Ghana)</p><p>Background: Microfinance is one major approach to offering financial services to the majority, (mainly poor people) in developing countries. Traditionally, most of these institutions largely operate based on support by international donor agencies. Research into this field has shown that a microfinance institution has the ability to maximize profits by commercializing its services.</p><p>Problem: The research problem is to find out how the Sinapi Aba Microfinance Institution, (Ghana) can maximize profits as a result of commercialization of operations.</p><p>Purpose: The main purpose of this research is to illustrate to the Sinapi Aba Microfinance Institution how it could maximize profits through the commercialization of its operations.</p><p>Method: The research is a study that uses the qualitative approach. Relevant information for the theoretical background and the Sinapi Aba has been organized through primary and secondary data search. The primary data is based on a telephone interview with Mr.Opata Narh, managing director at Sinapi Aba Microfinance Institution in Oda, and a questionnaire sent through an attached e-mail to Mrs. Georgina Ocansey, the human resource manager to solicit her opinion on the same subject. Information’s were also gathered from the institutions home page. The secondary data was sourced from books and articles from the Mälardalen University library and internet sources within this field of study.</p><p>Conclusion: In an effort to illustrate to the Sinapi Aba Microfinance Institution how it could be self sufficient through profit maximization, the author was able to base his argument on the theories used in the frame of reference in connection with the findings obtained from the telephone interview, questionnaire and the institutions home page. This also helped the author establish the fact that the Sinapi Aba Microfinance Institution can maximize profit through the commercialization of its services. Profit maximization could therefore be achieved by developing its human resources, mobilizing savings, supervision and regulative mechanisms and finally marketing and competitive positioning.</p>
10

Commercializing a microfinance institution to maximize profit : (A study of the Sinapi Aba Microfinance Institution-Ghana)

Allotey, Daniel January 2008 (has links)
ABSTRACT Date: 2008-06-23 Level: Bachelor Thesis in Business Administration, Basic Level 300, 15 ECTS-Points Author: Daniel Allotey Tutor: Per Nordqvist Title: Commercializing a microfinance institution to maximize profit (A study of the Sinapi Aba Microfinance Institution-Ghana) Background: Microfinance is one major approach to offering financial services to the majority, (mainly poor people) in developing countries. Traditionally, most of these institutions largely operate based on support by international donor agencies. Research into this field has shown that a microfinance institution has the ability to maximize profits by commercializing its services. Problem: The research problem is to find out how the Sinapi Aba Microfinance Institution, (Ghana) can maximize profits as a result of commercialization of operations. Purpose: The main purpose of this research is to illustrate to the Sinapi Aba Microfinance Institution how it could maximize profits through the commercialization of its operations. Method: The research is a study that uses the qualitative approach. Relevant information for the theoretical background and the Sinapi Aba has been organized through primary and secondary data search. The primary data is based on a telephone interview with Mr.Opata Narh, managing director at Sinapi Aba Microfinance Institution in Oda, and a questionnaire sent through an attached e-mail to Mrs. Georgina Ocansey, the human resource manager to solicit her opinion on the same subject. Information’s were also gathered from the institutions home page. The secondary data was sourced from books and articles from the Mälardalen University library and internet sources within this field of study. Conclusion: In an effort to illustrate to the Sinapi Aba Microfinance Institution how it could be self sufficient through profit maximization, the author was able to base his argument on the theories used in the frame of reference in connection with the findings obtained from the telephone interview, questionnaire and the institutions home page. This also helped the author establish the fact that the Sinapi Aba Microfinance Institution can maximize profit through the commercialization of its services. Profit maximization could therefore be achieved by developing its human resources, mobilizing savings, supervision and regulative mechanisms and finally marketing and competitive positioning.

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