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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.

Comparing apples and oranges: why infant bone collagen may not reflect dietary intake in the same way as dentine collagen

Beaumont, Julia, Craig-Atkins, E., Buckberry, Jo, Haydock, H., Horne, P., Howcroft, R., MacKenzie, K., Montgomery, J. 06 September 2018 (has links)
Yes / Objectives: Recent developments in incremental dentine analysis allowing increased temporal resolution for tissues formed during the first 1000 days of life have cast doubt on the veracity of weaning studies using bone collagen carbon (δ13C) and nitrogen (δ15N) isotope ratio data from infants. Here we compare published bone data from the well-preserved Anglo-Saxon site of Raunds Furnells, England, with co-forming dentine from the same individuals, and investigate the relationship of these with juvenile stature. The high resolution isotope data recorded in dentine allow us to investigate the relationship of diet with juvenile stature during this critical period of life. Materials and methods: We compare incremental dentine collagen δ13C and δ15N data to published bone collagen data for 18 juveniles and 5 female adults from Anglo Saxon Raunds Furnells alongside new data for juvenile skeletal and dental age. An improvement in the method by sampling the first 0.5mm of the sub-cuspal or sub-incisal dentine allows the isotopic measurement of dentine formed in utero. Results and Discussion: δ13C profiles for both dentine and bone are similar and more robust than δ15N for estimating the age at which weaning foods are introduced. Our results suggest δ15N values from dentine can be used to evaluate the maternal/in utero diet and physiology during pregnancy, and that infant dentine profiles may reflect diet PLUS an element of physiological stress. In particular, bone collagen fails to record the same range of δ15N as coforming dentine, especially where growth is stunted, suggesting that infant bone collagen is unreliable for weaning studies. / Funded in part by the NERC standard grant NE/F018096/2; University of Bradford.


Wu, Salene M. January 2009 (has links)
No description available.

The influence of chronic physiological stress on financial health perceptions

Zepp, Phillip January 1900 (has links)
Doctor of Philosophy / Department of Human Ecology-Personal Financial Planning / Sonya L. Britt / There is limited research on physiological stress in the financial planning field. While the literature shows a clear relationship between physiological stress and physical health, little is known about the relationship between physiological stress and financial health perceptions. With Lazarus and Folkman’s (1984) theory of cognitive appraisal serving as the framework for this study, three multivariate regressions investigated the relationship between chronic physiological stress and financial health perceptions as measured by changes in financial satisfaction, changes in financial strain, and expectations about one’s financial situation in the future. The sample consisted of 703 individuals that were recruited from 2011-2014 to participate in the Midlife in the United States Refresher study. Based on non-imputed data, respondents were evenly split between male and female and between 25 and 76 years old with a mean age of 51 years old. Respondents were also mostly white, working, married, and had some college education. The sample reported mean household income of $71,052 and a net worth of $586,329. The mean salivary cortisol level was 16.06 Nanomoles per litre (nmol/L), and respondents reported better than the median score for self-reported health status. When comparing before the recession to present day, the mean responses from respondents indicated that their financial strain remained about the same, but financial satisfaction declined. Respondents reported better than the median score for expectations about their financial future. An ordinary least squares regression was used to model changes in financial satisfaction. A cumulative logistic regression was used to model changes in financial strain and expectations about one’s future financial situation. The model results provided support for several key hypotheses formed from the theoretical framework. In particular, salivary cortisol, the proxy for chronic physiological stress, had a statistically significant negative relationship with expectations about one’s future financial situation. An increase in chronic physiological stress was associated with lower expectations about the financial future. There was not a statistically significant relationship between salivary cortisol and changes in financial satisfaction or changes in financial strain. Given the sparse physiological stress research that exists in the financial planning field, this study provides researchers and practitioners with new information regarding the impact of chronic physiological stress on financial health perceptions. Measuring physiological stress in a non-experimental setting gives researchers a different approach to understanding the impacts of physiological stress. For practitioners, uncovering the relationship between chronic physiological stress and financial health perceptions might promote the use of stress reductions as part of holistic approach to financial planning.

A Model for Determining Induced Physiological Stress During Respirator Wear

Meyer, Steve D. (Steve Douglas) 12 1900 (has links)
A model was developed to predict the increased physiological effort of wearing a respiratory protective device. Specifically, the model was designed to predict the effects of varying ventilatory demands on eleven respiratory variables of the man-respirator system, breath frequency (f_b), tidal volume (V_t), inspiratory flow (dvi/dt), expiratory flow (dve/dt), inspiratory mask pressure (P_mi), expiratory mask pressure (P_me), inspiratory intrathoracic pressure (P_ii), expiratory intrathoracic pressure (P_ie), inspiratory mask work (W_mi), expiratory mask work (W_me), and mask leakage index (L_i). The model was tested by experiment in which three male subjects underwent maximal exercise testing with and without the "pressure-demand" respirator. The eleven variables were determined for each thirty second period utilizing on-line computer analysis. Application of the model to these experimental conditions resulted in significant (p<.001) relationships between each of the predicted and observed variables.

A comparison of methods of quantifying and assessing the behaviour and welfare of Bornean orangutans (Pongo pygmaeus) : a case study at Twycross Zoo

Bentley, Ruth H. January 2018 (has links)
The maintenance of both the psychological and physiological health of captive animals is a key priority of modern zoos. Recognising that characteristics of the captive environment have the potential to decrease animal welfare, methods for quantifying and assessing welfare have been developed as part of the process for improving animal welfare. Traditionally, observations of animal behaviour and quantifying time budgets in relation to those of the animals’ wild counterparts have been utilised to assess animal welfare. Hormonal assays have also been implemented to quantify the physiological stress response of animals in captivity and identify the extent of stress being experienced. Each of these methods focuses on a different indicator of animal welfare, is quantified in different ways and provides a different perspective on the welfare of the animals. Given the limited time and financial budgets available to zoos and animal carers, identifying the most appropriate method of welfare assessment would be advantageous in helping to secure the best possible health of captive animals and to maximise their value in captivity. This thesis implemented both behavioural observations and hormonal assays to identify the strengths and weaknesses of each methodology, and make recommendations for future research. The study involved a group of four Bornean orangutans (Pongo pygmaeus) housed at Twycross Zoo. Behavioural observations involved continuous group sampling and the development of an ethogram to record a comprehensive account of orangutan activity over the course of a 12 week enrichment programme. Simultaneous to these observations, faecal samples were collected from each orangutan and processed via Enzyme Immunoassay (EIA) to quantify levels of faecal glucocorticoid metabolites (fGCM) in each sample. While recognising the recent developments in ecological analytical methods, the capacity for extending network analysis beyond the application to social networks, and its use as a welfare assessment tool were explored. Behavioural and space-use networks were developed using data from a second study of the orangutans housed at Twycross Zoo. The flexibility of network analysis in visually representing different data types allowed for the intuitive representation of complex behavioural data. Further research investigated the use of network metrics in providing deeper insights into animal behaviour and space use patterns. In addition, bipartite networks were assessed for their potential to detect and show patterns in the relationships between two sets of behavioural data. Each of the methods used had a number of strengths and weaknesses, but importantly each contributed a different perspective in the assessment of behaviour patterns and welfare, suggesting that an integrated approach to behaviour studies utilising several methods would be ideal. Cost and logistic constraints make this unlikely in most cases. However, the thesis ends with a look to the future and the recognition that the current rapid development of technology for use in animal behaviour studies, coupled with equally rapid development of analytical techniques, may help to dramatically increase the amount of information gained from the average animal behaviour study in the future. Such improvements have never been more urgent, with the requirement for understanding animal behaviour in light of current extinction rates within the context of habitat destruction and climate change. It is hoped that this thesis will make a contribution to improving future animal behaviour and welfare studies by providing an assessment of both traditional methods of study as well as demonstrating the use and potential of new ways of applying network analysis within such studies.

Experience of Microaggressions: White Bystanders’ Physiological and Psychological Reactions

Reveles, Alexandra K. 01 May 2019 (has links)
The negative impacts of discriminatory events to the physiological and psychological stress of the recipient has been thoroughly documented. However, there is little to no evidence about the impacts to bystanders of these events, particularly White bystanders. Psychological impacts may emerge through academic achievement, which has implications for educational institutions and their diversity initiatives. This study examined the impact of witnessing discriminatory events on academic achievement, biological markers of distress, and emotional distress. Academic achievement was negatively impacted for participants in the microaggression and blatant racism conditions when compared to a control condition. Study participants also experienced negative emotional impacts. These were evident through a decrease of positive emotion and an increase of negative emotion throughout the study. Counter to the stated hypothesis, biological markers of distress did not demonstrate a negative impact from the discriminatory event. Microaggressions, specifically, were not found to have negative impacts on academic achievement. There were also no differences in the relationship between biological markers of distress and academic achievement among the three conditions. These findings suggest that discriminatory behavior negatively impacts White bystanders emotional state and academic achievement.

Illness demands and social support during recovery from a cardiac illness event /

Yates, Bernice Helen. January 1989 (has links)
Thesis (Ph. D.)--University of Washington, 1989. / Vita. Includes bibliographical references.

The effects of pets on children's stress responses during medical procedures /

Wells, Marjorie Joan. January 1998 (has links)
Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [139]-155).

Estresse em enfermeiros com atuação em Unidade de Terapia Intensiva / Stress in nurses who work in intensive with care

Cavalheiro, Ana Maria [UNIFESP] 27 February 2008 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:50:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-27. Added 1 bitstream(s) on 2015-08-11T03:25:43Z : No. of bitstreams: 1 Publico-10759a.pdf: 1261042 bytes, checksum: 7ed9fba23bd66a95b6384a59ec4daf59 (MD5). Added 1 bitstream(s) on 2015-08-11T03:25:43Z : No. of bitstreams: 2 Publico-10759a.pdf: 1261042 bytes, checksum: 7ed9fba23bd66a95b6384a59ec4daf59 (MD5) Publico-10759b.pdf: 1093423 bytes, checksum: 62b5d68293f1fab2d87f2ed60a9f5341 (MD5) / Objetivos: O presente estudo teve como objetivos estudar a presença de estresse e sua intensidade caracterizada pelos sintomas clínicos e agentes estressantes em enfermeiros que trabalham em unidades de terapia intensiva e identificar os fatores estressantes em unidade de terapia intensiva relacionado à sua interferência na saúde destes profissionais. Método: realizou-se um estudo transversal com setenta e cinco enfermeiros. Os dados foram obtidos por questionário, que contém informações sobre os fatores estressantes (escores de estressores) e sobre os sintomas clínicos (escore de sintomas clínicos). A análise foi realizada por meio do uso de coeficientes de correlação de Pearson e ajustados modelos lineares generalizados, a significância estatística para se manter no estudo foi de p<0,05. Resultados: análise dos resultados mostrou que os enfermeiros apresentaram intensidade moderada de estresse. Os profissionais que referiam insatisfação com o trabalho tiveram em média 8,34 pontos a mais no escore de sintomas clínicos e cada ponto obtido para o escore de situações críticas corresponde a um aumento de 0,62 pontos no escore de sintomas clínicos, referentes às alterações cardiovasculares, gastrintestinais e músculo-esquéletico. Conclusão: o enfermeiro que exerce sua atividade profissional em unidade de terapia intensiva (UTI) apresenta intensidade moderada de estresse de acordo com escala proposta;os sintomas clínicos estão diretamente relacionados aos fatores estressantes e a intensidade de estresse; os fatores estressantes e os sintomas clínicos estão associados à insatisfação com o trabalho. / Purpose: The objective of this study was to evaluate stress and its intensity in nurses who work in intensive care units. We analyzed their clinical symptoms and identified the stressing factors’ influence in the health of these professionals. Methods: This was a transversal study including seventy five nurses. The data was collected by questionnaire; including information about stress factors (stress score) and clinical symptoms (clinical symptoms score). The statistical analyses were performed using Pearson correlation coeficients and adjusted linear modeling. A p value <0.05 was used to declare statistical significance. Results: The nurses had a moderate intensity of stress. Those professionals that were dissatisfied with their work presented on average 8.34 points more in the clinical symptoms score than those nurses who were not dissatisfied. Each point in the critical situations score corresponds to an increase of 0.62 points in the clinical symptoms score. This last score refers to cardiovascular, gastro-intestinal and muscular-skeletal changes. Conclusion: The nurses who work in intensive care units had moderate intensity of stress, according to the questionnaire used in this study. The clinical symptoms are positively related to the stress factors and to the intensity of stress. The stress factors and the clinical symptoms are associated with work dissatisfaction. / TEDE / BV UNIFESP: Teses e dissertações

The Effects of Neuroendocrine Stress on Larval Development

Kirschman, Lucas James 01 August 2017 (has links) (PDF)
Environmental stressors are ubiquitous. Animals will face a variety of natural and anthropogenic stressors throughout their life cycle. The physiological mechanisms that mediate stressful stimuli can have pleiotropic effects on life history traits, such as reproduction and development. Furthermore, these phenotypic changes can affect larger-scale ecosystem dynamics, like nutrient cycling and disease epizootics. Animals are not equally susceptible to stressors across all stages of their life cycles. Critical windows of development, common in young and developing animals, are time periods when stressors have an outsized effect and can permanently alter phenotype. Larval amphibians use a critical window in late larval development wherein activation of the hypothalamic-pituitary-adrenal/interrenal (HPA/I) axis speeds their development, allowing them to metamorphose and escape suboptimal aquatic habitat. Accelerated development comes at a cost, the glucocorticoid (GC) hormones secreted by the HPA/I axis affect other systems such as growth, immune function, metabolism, and nutrient use. In chapter two, I investigated the effects of GC hormones on metabolism, energetics, and nutrient oxidation in larval wood frogs. The results show that GC hormones increase metabolism, reduce lipid stores, and increase protein oxidation during metamorphic climax. Chapter three focuses on the effects of GC hormones on immune function and r susceptibility. I found that chronic exposure to GC hormones increased ranavirus replication in infected wood frog larvae, but did not affect survival time. This could contribute to ranavirus epizootics. Acute GC hormone exposure increased survival, possibly by activing the inflammatory response. Finally, chapter four investigates the effects of GC hormones on nutrient stoichiometry. I found that larvae treated with GC hormones had lower nitrogen to phosphorus ratios, possibly because disrupted skeletal ossification. They also had reduced phosphorus excretion, which could affect ecosystem-level processes like nutrient cycling and decomposition.

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