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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

Spatiotemporal tuning for position and velocity in primate primary motor cortex neurons /

Fellows, Matthew R. January 2005 (has links)
Thesis (Ph.D.)--Brown University, 2005. / Vita. Thesis advisor: John P. Donoghue. Includes bibliographical references (leaves 40-48, 78-80, 148-151, 229-231, 267-268). Also available online.
2

Identification and characterization of stem cell-like populations in primate intervertebral disc

Huang, Shishu., 黄石书. January 2012 (has links)
Upon aging, the intervertebral disc (IVD) inevitably undergoes degeneration characterized by biochemical and morphologic changes. IVD degeneration can lead to multiple clinical disorders such as back and neck pain, and myelopathy. Low back pain can disable up to 85% of the adult population and results in a significant restriction of social activities and inability to work. Such disorder incurs billions of dollars in medical expenditures each year. Despite advances in the detection and treatment of the degeneration, the regeneration of the IVD remains low because current therapies are limited by exogenous curing approaches. New strategies for the reversal of IVD degeneration, including gene, cytokine, and stem cell therapies that can influence the anabolic and catabolic pathways in disc cells have been under investigation. These therapies aim to rejuvenate or replace diminished nucleus pulposus cells in the degenerative IVD. Recent reports have put forth a proposal of “endogenous disc stem cells”, suggesting that cells derived from the degenerative IVD tissue possess stem cell properties. These putative stem cells are believed to regulate the development and homeostasis of the IVD tissue. In this study, we identified and characterized a stem cell population from the IVD of healthy Rhesus monkey, termed disc stem/progenitor cells (DSCs). We show that the DSCs possess clonogenicity, multipotency and self-renewal capacity. The DSCs are phenotypically similar to bone marrow mesenchymal stem cells (BMSCs) but they are not identical. The DSCs show a faster growth rate under hypoxia than normoxia. DSCs derived from nucleus pulposus (DSCNP) show a stable expression level of hypoxia inducible factor-1 alpha (Hif-1a) in response to hypoxia. DSCs derived from annulus fibrosus (DSCAF) are more resistant to apoptosis under hypoxia than DSCNP. More importantly, small leucine-rich proteoglycans (SLRPs) are identified as important DSC niche components. We show that biglycan (bgn) and decorin (dcn) reduce the susceptibility of DSCs to hypoxia-induced apoptosis by promoting the expression of hypoxia inducible factors (HIFs). Our findings suggest that DSCs rely on the unique niche components for survival. In summary, our findings propose the existence of endogenous stem cells in IVD. Further study of the DSCs may provide new insights into the biology of IVD and facilitate the design of new strategies to treat disc degeneration in future. / published_or_final_version / Orthopaedics and Traumatology / Doctoral / Doctor of Philosophy
3

Rapid Analysis of Fecal Glucocorticoid Metabolites: Testing an Alternative Method for Analyzing Stress Markers in Chimpanzees

Unknown Date (has links)
This study explores the application of two methods of spectroscopy; Near Infrared spectroscopy (NIR) and Fourier transform spectroscopy (FTIR) as alternative approaches for measuring glucocorticoid metabolites in chimpanzee feces. The goals of this study were twofold: The first was to determine if cortisol can be identified within the NIR and/or FTIR spectra of chimpanzee fecal hormone extract in ethanol solution. The second objective was to determine the capability of NIR and FTIR to predict FGM concentrations obtained using standard laboratory methods. Fecal glucocorticoid concentrations measured by Enzyme Immunoassay were used as the reference data of partial least square (PLS) regression of fecal extract NIR spectra and FTIR spectra. Low accuracies (NIR: R2 = 0.152; FTIR: R2 = 0.199) were obtained from regression models using data from both methods. Though this study did not successfully demonstrate the feasibility of using NIR and FTIR to qualify and quantify FGMs, it is likely not a reflection of the capabilities of the technology, but rather of appropriate sample types and preparation methods. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
4

Subcortical pathways for colour vision /

Szmajda, Brett A. January 2006 (has links)
Thesis (Ph.D.)--University of Melbourne, The National Vision Research Institute of Australia and Dept. of Optometry & Vision Sciences, 2007. / Typescript. Includes bibliographical references (leaves 95-111).
5

Training in a laboratory environment : methods, effectiveness and welfare implications for two species of primate

McKinley, Jean January 2004 (has links)
The use of Positive Reinforcement Training (PRT) for co-operation during routine husbandry and laboratory procedures is widely advocated as a means of promoting the welfare of nonhuman primates. However, while research originating in US zoos provide qualitative descriptions of how PRT may be used in the training of a wide variety of species, quantitative data and evidence to support the view that PRT reduces stress predominately comes from laboratory studies of primates whose training may have used other methods. Despite official guidelines, training is rarely carried out in the UK and the educational and wider organisational structures concerning training, present in the US are largely absent. The techniques used in the UK were assessed through detailed observations recorded when four stump-tailed macaques were trained to co-operate during venipuncture. Data recorded during training sessions showed that although food rewards were given, their delivery was slow and inconsistent. A certain amount of coercion was used which violates a principle of PRT which states that co-operation should be voluntary. The macaques showed increasing resistance to the process and a mild but detrimental effect on the subsequent behaviour of the study animals. When training resumed 18 months later there were considerable improvements in the techniques used. The macaques showed a greater willingness to participate and there were no significant changes in their behaviour when training days were compared to those when training did not take place. The behaviour of the macaques during venipuncture was judged to be arising from engineered compliance rather than voluntary co-operation. However, it was concluded that the technique observed, if carried out correctly, was a reasonable compromise between forced restraint and voluntary co-operation given the paucity of evidence showing the effectiveness of PRT for invasive procedures. However, it was also concluded that the use of coercion should be recognised and provide a focus for future refinement. The effectiveness and welfare implications ofPRT was assessed through the training of common marmosets to target and allow in-homecage weighing and to provide urine samples. It was found that the trained animals perfonned reliably and that time invested in training could be recouped through faster data collection. Following a period of training or increased positive contact with humans, observations of marmoset behaviour showed a decrease in stress related behaviours and an increase in allogrooming supporting the view that improved relations with humans had a beneficial effect. Following exposure to a mild stressor, trained marmosets showed no elevation in levels of urinary cortisol or stress related behaviours. Untrained animals showed increased levels of locomoting and selfscratching following exposure to the same stressor. It was concluded that PRT successfully reduced the stress associated with the presence of, and manipulation by, humans. Final recommendations were that training can promote the welfare of nonhuman primates and should be used in UK laboratories to a greater extent than is currently the case. However, the lack of educational opportunities for animal trainers in the UK needs to be addressed. It was also recommended that in light of the growing evidence showing the benefits that can arise from training and good relations with humans, the zero-handling policy practiced in many UK zoos should be reassessed.
6

Linking welfare and quality of scientific output in cynomolgus macaques (Macaca fascicularis) used for regulatory toxicology

Tasker, Louisa January 2012 (has links)
Cynomolgus macaques (Macaca fascicularis) are the most commonly used non-human primate for research and testing in Europe. Their principal use is in preclinical safety testing of new pharmaceuticals to assess risk of adverse effects, as indicated by changes in a core battery of physiological measures before human exposure. Regulatory studies are strictly controlled through legislation and codes of practices underpinned by the principles of humane science, the 3Rs; Replacement, Reduction and Refinement. Despite the link between good welfare and good science now universally made in codes of practice, legislation and the literature, there are few studies aimed at systematically examining the link and almost no quantitative data from cynomolgus macaques used for toxicology. The main aim of this thesis was to examine the link between Refinement, animal welfare and scientific output for this important animal model, piggy-backing on regulatory studies conducted by a large contract research organisation. In the laboratory, animal welfare is formally considered in terms of Refinement which has evolved to include both the reduction of negative welfare states and the proactive enhancement of positive welfare over the animal’s lifetime. A multidisciplinary approach to welfare assessment including measures of behaviour, physiology and physical health, and which built upon current unit procedures was undertaken to produce an overall assessment of welfare in cynomolgus macaques. Macaque facial expressions, vocalisations, activity and position in the home cage, body weight change, body condition and alopecia scores were found to be reliable indicators of welfare state and would be most feasible for care staff to monitor. The concept of quality of scientific output was defined in relation to toxicological findings and includes sensitivity, reliability and repeatability of individual measures in the core battery (e.g. heart rate, blood pressure, haematology, clinical chemistry and organ weights). The link between welfare and quality of scientific output was then systematically explored with Refinements to macaque use in regulatory studies. The first, a data mining study, undertaken to quantify the effects on biological data recorded from cynomolgus macaques, used in regulatory studies over an eight-year period as the CASE sponsor transitioned from single to permanent group housing, found the effects to be highly variable on individual parameters in the core battery and in some instances welfare-positive effects of group housing were confounded by concurrent changes in standard operating procedures. A further study of planned Refinements to macaque-care staff interaction through enhanced socialisation was found to help animals cope better with husbandry and scientific procedures and enhance quality of cardiovascular measures recorded at baseline. In light of these findings a number of recommendations are made including a framework of terms useful for measuring quality of scientific output, a welfare assessment framework and Refinements to husbandry and scientific procedures for cynomolgus macaques used in regulatory toxicology. Because of their capacity to suffer it is both ethically and scientifically important that macaque welfare is maximised and their use results in valid and reliable experimental outcomes informing on the safety and efficacy of new pharmaceuticals prior to human exposure.

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