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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

Avian rucksacks for science : in search for minimum-impact tagging procedures for birds

Vandenabeele, Sylvie Paule January 2013 (has links)
Voltaire wrote "With great power comes responsibility", a quote which can easily be applied to scientists nowadays whose work effectively shapes the life of billions of living beings, operating through various disciplines from medicine through to ecology. To help scientists working with wild creatures, animal-attached electronic devices, commonly referred to as 'tags', have become indispensable tools, pushing the boundaries into the unimaginable enabling, for instance, information to be sent from animals into space and back via satellites. This 'great power' does indeed come with 'responsibility' however, as evidence piles up of the deleterious effects of tags on their animal carriers. The aim of this doctoral project is to provide scientists with an analytical framework within which to examine the effects of external tags on wild animals with a view to providing guidelines informing best practise in animal tagging. For that purpose, an integrative, multidisciplinary approach was undertaken which, from a theoretical to an experimental level, assessed the impact of tags on birds. With a main focus on marine birds, the results show that tag effects ranged from behavioural aberrations to compromised energetics, ultimately reducing both flying and swimming performance. This impact varied as a function of tag size, mass, shape, position and attachment, as well as being dependent on bird morphology and lifestyle. The length of time to which a bird is exposed to deleterious tag effects appears critical since these effects can snowball over time. Fortunately, and as reported in this thesis, there are simple rules which can be implemented to help minimise tag impact even for long-term studies, mainly through an optimised tag design and innovative attachment system. So, happily, this thesis shows that by careful thinking, we can benefit maximally from our 'great power' and thus ensure that our 'responsibilities' to wild animals are best informed.
2

Visualizing discourses and governance of human embryonic stem cell research in South Korea (in comparison to the UK)

Kim, Leo Dhohoon January 2016 (has links)
This thesis investigates how the discourses and governance of human embryonic stem cell (hESC) research operated in South Korea. Comparing South Korea to the UK in three fields (government, newspapers, and public responses) and reflecting scientific misconduct in the South Korean scientists' community, the study tries to identify hidden variables that influenced the national trajectory. To capture dynamic yet underrepresented national and cultural characteristics, the author has analysed microscopic interactions including actors' utterances, media framing, human relations and strategies. By using the methodology to pursue sociological approaches with semantic and social network analysis, concepts usually inferred and narrated by the researcher gain a visual and measurable representation in terms of Actor-Networks. The study concludes that the failure to institutionalise a sustainably cooperative research environment and (bio)ethical regulation in South Korea is an outcome of the lack of reflexive social discourse and deliberative governance. The national characteristics mainly derived from the subdued status of experts, scientists, in the government and the predominant media framing to represent life science as a mere tool to economic development. More crucially, people in general accepted the economy-oriented discourse. From the outcome of the semantic network analysis, it turns out that the public attitude was mainly constructed from people's limited objective and desire to utilise science to pursue social status and economic development. South Korean people largely disregarded the possible threat of hESC research to women's bodies that was related to human rights. A new scientific leadership should recognise this culturally embedded atmosphere and more effectively mediate government, mass media, lay public and scientific community by reconstituting expert role, critical media framing of science, and broader deliberation on the social function of scientific knowledge.
3

The conduct and management of large clinical trials in hypertension / John Marley

Marley, John January 1992 (has links)
Includes 4 published papers by the author as part of appendix 9 / Bibliography: leaves 1-19 (second sequence) / System requirements for accompanying computer disk: IBM-compatible computer. Other requirements: Dbase. / 1 v. (various pagings) ; / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Summary: describes and evaluates an economical method of collecting a large amount of data on thousands of patients suffering from essential hypertension and establishes the reliability of the data collected in this way. Also provides information on the tolerability and effectiveness of nifedipine / Thesis (M.D)--Dept. of Clinical and Experimental Pharmacology, University of Adelaide, 1993
4

The Functional Assessment Of Fluorecently Tagged Adenosine A2a And Dopamine D2 Receptors And Qualitative Analysis Of Dimerization Of Adenosine A2a And Dopamine D2 Receptor By Using Fret

Akkuzu, Selin 01 January 2013 (has links) (PDF)
Recently, several studies have demonstrated that G protein coupled receptors exist as homo/heterodimers or oligomers. Adenosine A2A receptors and dopamine D2 receptors are present as both homo- and heterodimer. In the GABAergic striatopallidal neurons A2AR are co- localized with D2 receptors (D2R), and establish functional A2AR-D2R heteromers, which modulates dopaminergic activity. Due to be involved in physiological processes, these receptors bear critical roles. Dopamine receptors play critical role in dopaminergic pathways in regulation of memory, food intake and psychomotor activity, etc. On the other hand, adenosine A2A receptors are involved in the regulations of neurotransmission, immune response and cardiovascular systems. Dopamine D2R andadenosine A2AR have been shown to interact in striatum and modulate dopaminergic activity The purpose of this study is to assess the functionality of EGFP (enhanced green fluorescent protein) and mCherry (a red fluorescent protein) tagged adenosine A2A and dopamine D2 receptors and to detect homo/ hetero-dimerization of these receptors in live cells via Fluorescence Resonance Energy Transfer (FRET). Understanding the mechanisms of the interaction between adenosine and dopamine signaling will help us to figure out some molecular mechanism of neurophysiological disorders. Furthermore, the fluorescence based live cell model could be used to observe the effects of potential anti-psychotic drugs on the interaction of these two receptors.
5

The Development of a Research Technique for Low Speed Aeroacoustics

McPhee, Adam D. January 2008 (has links)
The aerodynamic sound generated by wind turbines was identified as a growing concern within the industry. Prior to performing wind turbine aeroacoustic research, however, a technique suitable for studying low speed airfoils needed to be designed, serving as the primary research objective. A review of aeroacoustic theory and literature indicated that low speed flows are best studied using experimental methods, leading to the design of a near field pressure measurement technique. To facilitate the near field pressure measurements, a custom piezoelectric sensor was developed, exhibiting a pressure and frequency range of approximately 67 to 140[dB], and 100 to 10000[Hz], respectively. As a secondary research objective, a series of experiments were performed to validate the designed technique. The experiments were performed in a non-anechoic wind tunnel using a cylindrical test specimen. Using the near field pressure measurements, as well as a simple far field measurement, the sources of aerodynamic sound were effectively resolved. The Strouhal numbers corresponding to the contributing flow structures were generally within 1.5[%] of correlation based predictions. The near field pressures were consistently 10 to 15[dB] higher than the far field, quantifying the benefit of the near field technique. The method was also effective in detecting the decreasing coherence of the aeroacoustic sources with increasing Reynolds number. A minor deficiency was observed in which the ability to localize aeroacoustic sources was impeded, however, the cylinder experiments were particularly vulnerable to such a deficiency. Although the near field pressure measurements were shown to be effective in characterizing the aeroacoustic sources, a number of recommendations are presented to further improve the flexibility and measurement uncertainty of the experimental technique.
6

The Development of a Research Technique for Low Speed Aeroacoustics

McPhee, Adam D. January 2008 (has links)
The aerodynamic sound generated by wind turbines was identified as a growing concern within the industry. Prior to performing wind turbine aeroacoustic research, however, a technique suitable for studying low speed airfoils needed to be designed, serving as the primary research objective. A review of aeroacoustic theory and literature indicated that low speed flows are best studied using experimental methods, leading to the design of a near field pressure measurement technique. To facilitate the near field pressure measurements, a custom piezoelectric sensor was developed, exhibiting a pressure and frequency range of approximately 67 to 140[dB], and 100 to 10000[Hz], respectively. As a secondary research objective, a series of experiments were performed to validate the designed technique. The experiments were performed in a non-anechoic wind tunnel using a cylindrical test specimen. Using the near field pressure measurements, as well as a simple far field measurement, the sources of aerodynamic sound were effectively resolved. The Strouhal numbers corresponding to the contributing flow structures were generally within 1.5[%] of correlation based predictions. The near field pressures were consistently 10 to 15[dB] higher than the far field, quantifying the benefit of the near field technique. The method was also effective in detecting the decreasing coherence of the aeroacoustic sources with increasing Reynolds number. A minor deficiency was observed in which the ability to localize aeroacoustic sources was impeded, however, the cylinder experiments were particularly vulnerable to such a deficiency. Although the near field pressure measurements were shown to be effective in characterizing the aeroacoustic sources, a number of recommendations are presented to further improve the flexibility and measurement uncertainty of the experimental technique.
7

Investigation Of Telomerase Activity In Diagnosis Of Endometrial And Cervical Cancer

Eskiocak, Ugur 01 July 2007 (has links) (PDF)
Human telomerase is a ribonucleoprotein complex that adds hexameric TTAGGG repeats to the ends of chromosomes in order to prevent their shortening. Telomerase activity has been evaluated for its diagnostic and prognostic value in cancer since it is observed in most malignancies but not in most normal somatic tissues. In this study telomerase activity was examined in tumor specimens obtained from cervix, endometrium and their non-cancerous regions by an improved telomeric repeat amplification protocol (TRAP) &ndash / silver staining assay. Appearance of characteristic TRAP leader with 6 base pair increments indicate a positive result and was observed in all cancerous and some of the non-cancerous tissues. Telomerase activities of carcinoma tissues and normal counterparts were compared by densitometric analysis after PCR. Significantly higher telomerase activity was observed in cervical carcinoma samples compared to normal adjacent tissue. No significant difference was observed between endometrium carcinomas and normal endometrial tissue in terms of telomerase activity. High telomerase activity in normal endometrium restricts the use of assay for detection of carcinogenesis. However, in cervical tissues an accurate quantification of telomerase activity by TRAP &ndash / silver stain assay may be valuable as a confirmatory assay.
8

Detection Of Bladder Tumor Recurrence By Fourier Transform Infrared Spectroscopy As A Novel Method

Aydin, Ozge Zelal 01 September 2009 (has links) (PDF)
Bladder cancer is one of the most common urogenital cancers worldwide. Two techniques commonly used for bladder cancer diagnosis are urine cytology and cystoscopy. Cytology is not sensitive for detecting tumors. Cystoscopy is an invasive technique which disturbs patient comfort. In the current study, we used Fourier transform infrared (FT-IR) spectroscopy as a novel method which is rapid and non-invasive to investigate the bladder tumor recurrence using the bladder wash samples collected in the course of control cystoscopy. This study is unique since it is the first one to use the bladder wash sample in the diagnosis of the bladder tumor by using FT-IR spectroscopy. Molecular investigation of the FT-IR spectra revealed many differences between control and tumor samples such as a considerable increase in protein, carbohydrate and nucleic acids content, and changes in protein and carbohydrate structure. On the basis of the spectral differences, cluster analysis was performed to differentiate between the control and tumorous spectra and we reached to an overall sensitivity (including all individuals with tumor) of 91.8%, a PUNLMP sensitivity of 83.3% and a papilloma sensitivity of 77.8% in spectral range 1444-1457 cm-1. Other spectral ranges also gave similar results. Our results showed that FT-IR spectroscopy can be used to detect the bladder tumors in bladder wash sample with higher sensitivity compared to cytology. In summary, we propose the utilization of the FT-IR spectroscopy for the detection of bladder tumors since specific spectral regions might be used as effective markers for the diagnosis.
9

Development Of A Sandwich-type Dna Array Platform For The Detection Of Label-free Oligonucleotide Targets

Cansiz, Sena 01 October 2010 (has links) (PDF)
DNA arrays have become a major bioanalytical method as they enable high-throughput screening and they can be manufactured on different surfaces depending on the nature of diagnostic purpose. However, current technologies to produce and detect arrays of DNA probes are expensive due to the requirement of specialized instrumentation. In this study we have established an array platform in sandwich hybridization format for the detection of label-free nucleic acid targets. Unlike direct hybridization, which is the main microarray hybridization principle, sandwich assay enables unlabeled target detection, lowering the cost and assay time. To this end, sequence specific signal development was achieved by a sandwich complex which is composed of a surface immobilized capture DNA probe (Probe1) and a fluorescein-tagged signal DNA probe (Probe 2), which are partially complementary to the sequence to be analyzed (target oligonucleotide). As the solid support of the array platform both 3-aminopropyl-3-methoxysilane (APTMS) activated and commercially purchased poly-L lysine coated glass slides were used and due to the less background noise property the latter one was preferred. Similarly, for the immobilization of the capture Probe (P1) onto the solid support two different methods were tried / heat immobilization and immobilization via a heterobifunctional cross-linker (HBCL). In regard to the experiments, it is observed that using a cross-linker instead of heat immobilization reduces the ratio of false negative control results in a significant manner. Following the solid support and immobilization method choice comparative optimization studies which include cross-linker type, probe concentration, sensitivity of the platform and hybridization conditions (sequence, temperature and duration) were conducted. Optimum hybridization signal was obtained with a 32.5
10

Development Of An Oligonucleotide Based Sandwich Array Platform For The Detection Of Transgenic Elements From Plant Sources Using Label-free Pcr Products

Gul, Fatma 01 October 2010 (has links) (PDF)
Advances in DNA micro and macroarray technologies made these high-throughput systems good candidates for the development of cheaper, faster and easier qualitative and quantitative detection methods. In this study, a simple and cost effective sandwich hybridization-based method has been developed for the rapid and sensitive detection of various unmodified recombinant elements in transgenic plants. Attention was first focused on the optimization of conditions such as time, concentration and temperature using commercial ssDNA, which in turn could be used for real sample detection. In this sandwich-type DNA chip platform, capture probes complementary to the first half of recombinant element (target adapter) were immobilized onto poly-L-lysine covered conventional microscope slides. PCR-amplified un-purified target adapter and biotin labeled detection probe, which is complementary to the second half of target adapter, were hybridized in solution-phase to complementary capture probes to create a sandwiched tripartite complex. Later, hybridization signal was visualized by the attachment of streptavidin conjugated Quantum Dot to the sandwiched complex under UV illumination. Sandwich based array system that has been developed in this study allows multiplex screening of GMO events on a single DNA chip platform. 35S promoter, NOS terminator, CRY1Ab and BAR target sequences were successfully detected on the same DNA chip platform. The platform was able to detect unlabeled PCR amplified DNA fragments of CaMV 35S promoter sequence and NOS terminator and BAR transgene sequences from transgenic potato plants and NK603 Certified GMO Reference material, respectively. The DNA-chip platform developed in this study will allow multiple detection of label-free PCR-amplified transgenic elements from real GMO samples on a single slide via a cost effective, fast, reliable and sensitive sandwich hybridization assay.

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