• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 13
  • 4
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 36
  • 36
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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

How early rearing conditions influence behaviour and survival of pheasants released into the wild?

Whiteside, Mark Andrew January 2015 (has links)
Translocation programmes, particularly when using the release of a captive reared population, often fail in their efforts to create a self-sustaining population. High mortality after release is a key issue and often associated with behavioural, physiological and cognitive deficiencies between the released population and their wild counterparts. Mitigation of these deficiencies is essential for successful translocation programmes. I showed that pheasants (Phasianus colchicus) that were reared in more naturalistic conditions early in life were better suited to the natural environment after they were released into the wild. Post release survival was improved with exposure to more naturalistic diets prior to release. We identified four mechanisms to explain this. Pheasants reared with more naturalistic diets: 1) foraged for less time and had a higher likelihood of performing vigilance behaviours; 2) were quicker at handling live prey items; 3) were less reliant on supplementary feed which could be withdrawn; 4) developed different gut morphology. Consequently birds reduced the risk of predation by reducing exposure time whilst foraging, while allowing more time to be vigilant, were better at handling and discriminating natural food items and not solely reliant on supplementary feed and had a better gut system to cope with the natural forage. Post release survival was also improved when pheasants were reared with access to perches. We identified three mechanisms to explain this. Pheasants reared with access to perches had: 1) a physiology to better enable the birds to fly to the higher branches and cope with prolonged roosting; 2) a higher propensity to roost off the ground at night; and 3) more accurate spatial memory. Consequently, birds were at a reduced risk of terrestrial predation by roosting at night, and accurately remember their new environment upon release. I also showed that these manipulations did not compromise the welfare of the individuals prior to release, as often feared when trying to create a naturalistic environment to a captive population. An additional mechanism that can affect the success of a translocation programmes, operating at the level of the population, considers the optimality of the mixture of released individuals that can influence a release programme. The personality of birds within a released population, tested prior to release into the wild, influenced their fate and dispersal. I suggest a number of release mechanisms that would aid the survival of a diverse range of behavioural types that are essential for the production of a self-sustaining population in a fluctuating environment. I showed that harem size is strongly influenced by the vigilance behaviour of its constituent members. Despite a shared interest in increasing harem size, their optimal size is influenced by trade-offs in individual vigilance behaviour, resulting in relatively small harems, perhaps leading to females associating with less preferred males, and males being surrounded by fewer females than they could mate with. The aim of this study was to provide the background to future work trying to promote developments to allow for better reproductive success. I finally discussed these results and how they add to the current knowledge of captive-rearing and release, and examine the wider implications of my results from the pheasant rearing system for reintroduction biology. I calculate the likely costs of interventions and extrapolated the potential economic and environmental benefits of implementing changes to the current methods of rearing.
2

Early development and the honesty of aposematic signals in a poison frog

Flores De Gracia, Eric Enrique January 2012 (has links)
The causes and consequences of variation in aposematic signals during immature stages are not clearly understood. This thesis explores the effects of early environment on the expression of aposematic signals in the green and black poison frog (Dendrobates auratus), and the consequences of variation in such components in the wild. It also explores how aposematic expression relates to levels of chemical defences in immature froglets. Embryos and larvae of poison frogs in the genus Dendrobates are known to be darkly pigmented. This thesis reports for the first time polymorphism in egg pigmentation in D. auratus and ontogenetic colour change through development reverting to a normally pigmented phenotype; however whether this pigmentation results from constraints or has adaptive consequences remains unclear. Evidence on how immature individuals allocate resources to growth and warning signalling is scarce. Experimental results in this thesis show that food supply during early environment affected body size and signal luminance in post-metamorphic froglets. Therefore the relative importance of these traits in relation to predation risk was further tested, using artificial prey in a field experiment. The results indicated that rates of attack by birds correlated negatively with body size, and on the contrary survival of artificial prey was independent of signal luminance. I therefore tested the hypothesis that in the wild larger, relatively well-nourished juvenile frogs are chemically better defended. I found that in fact larger juveniles are at a selective advantage conferred by their greater foraging efficiency and their superior levels of chemical defences. Overall, these results shows plasticity in aposematic traits in relation to early environmental nutrition in D. auratus; and suggests that acquiring large body size and similar integument colour as to adults are key determinants for survival during the early stages of their terrestrial life.
3

The early development of the health services of Papua New Guinea, 1870-1939

Spencer, Dora Margaret Unknown Date (has links)
This is an account of the two administration health services, and of those provided by the missions, through three succeeding regimes in British New Guinea/Papua and four successive regimes in German New Guinea/Territory of New Guinea. It also traces the evolution of Australian health administration in relation to the health services of Papua and New Guinea. Because the missions - although subsidised by the Administrations - developed medical services of their own before and quite separate from the administration services they are considered separately. Development of the health services was affected by the considerable constraints of insufficient finance, unfamiliar terrain, unfamiliar peoples and unfamiliar diseases. It was also affected by the emergencies of recurring epidemics of introduced diseases, by the interruption of the First World War and by the crisis of the Great Depression years. While in spite of the war years development was more or less continuous in Papua, New Guinea suffered almost complete disruption of health services for seven years, except to military personnel, during the years of occupation by Australian troops between 1914 and 1921. Nonetheless before the 1930s both the Papua and New Guinea health services were stable and expanding. Increasingly they were able to retain medical staff and to send officers to Australia for postgraduate training in tropical medicine and hygiene: also to undertake increasing medical training and dispersal of both European Medical Assistants and indigenous personnel on patrols and into village societies. The importance of adequate nutrition became a central issue, and continuing campaigns were conducted against hookworm, yaws, gonorrhoea and leprosy. The period of eighteen years between the establishment of Australia's Commonwealth Department of Health in 1921 and 1939 included an exploration of Australia's potential role in relation to health matters in Papua and New Guinea and more widely in the Pacific Region. The first, and a significant, contribution was that made by the Commonwealth Health Laboratory in Rabaul. As possibilities were explored and tried, or discarded, it became clear that the best means for Australia to assist in the health problems of the two Territories was by providing appropriate training for medical and other health personnel and for missionaries, and by conducting field surveys and research to help elucidate the epidemiology and pathology of diseases and questions of entomology. Other appropriate action was the initiation and conducting of international conferences on health matters of common concern, and the undertaking of the receipt and distribution of epidemiological intelligence for the Austral-Pacific Zone, of which New Guinea was a part. The period of the study ends in 1939, when the inevitability of war, and the likely inclusion of New Guinea in the conflict, became apparent.
4

Reaping the Seeds of Leadership: Evaluating a Proposed Model of Lifespan Leadership Development

Mitchell, Mary E. 08 1900 (has links)
Though research suggests that several factors are related to the onset of leadership, few researchers have endeavored to determine how these factors may interact to bring about early leadership development. A descriptive discriminant analysis was conducted to test the validity of early factors cited by Murphy and Johnson; namely, lower scores on measures of temperamental negative affect, higher scores of temperamental extraversion, effortful control, orienting sensitivity, authoritative parenting style, secure adult attachment, older relative age, and more reported team sports and extracurricular activities experiences were hypothesized to predict current and past leaders versus never leaders. Additional analyses investigated possible gender differences in how these early factors may predict leader occupancy. The results indicate that early factors are able to predict leadership status for male students, though a majority of the variance in leader status is still left unaccounted. Implications for future leadership development research and training are discussed.
5

Mutations affecting early development in the mouse

Hiraoka, Lea Ritsu January 1992 (has links)
No description available.
6

Immature development in wild Assamese macaques (Macaca assamensis)

Berghänel, Andreas 03 February 2016 (has links)
No description available.
7

Stimulace raného dětského vývoje pomocí metody "Estimulacion temprana" / Stimulation of early child development according to "Estimulacion temprana"

Maryšková, Tereza January 2018 (has links)
In my work I focused on the preventive group program Estimulación temprana, which is intended for children from 0 to 3 years old and their parents. Six case studies are presented to help analyze this program. Research has revealed that the program is working on children through coarse and fine motor, cognitive, speech and social development. The case reports indicate that the observed individuals did not deteriorate, on the contrary, there was a shift in the Brunet-Lezin scale. Activities take into account the developmental level of groups in which children are disaggregated by age, but the individual level of specific individuals reflects only to a small extent. The study also shows that Estimulación temprana leads parents to better orientation in education, targeted child care and out-of-school lessons and also helps them with effective ways of stimulating. From the subjective point of view of parents, the contribution of Estimulación Temprana lies above all in the possibility of sharing experiences, deregistering, establishing friendly relationships, and changing educational leadership. The results of this work provide a qualitative analysis in our not known program Estimulación temprana, whose specificity lies in the orientation to the whole of child development, thus being distinguished among...
8

Transgenerational Effects of Early Exposure to Soy Isoflavones on Reproductive Health and Bone Development in CD-1 Mice

Dinsdale, Elsa 23 August 2011 (has links)
Previous studies showed that early exposure to soy isoflavones resulted in improved bone mineral density (BMD) and bone quality that resulted in stronger bones in CD-1 mice. This study investigated whether the benefits to bone health are transferred to second generation (F2) females and if there are any adverse effects on reproductive health. First generation (F1) female CD-1 mice received subcutaneous injections of the isoflavones daidzein (DAI) and genistein (GEN) or corn oil from postnatal day (PND) 1 to 10 or 21. F1 and F2 treated-females experienced earlier pubertal onset and lengthened anogenital distance but only F1 had reduced fertility, histological abnormalities in the uterus and ovaries, and altered estrous cycling. F2 had higher BMD and stronger bones at 4 months of age. In conclusion, early life exposure to soy isoflavones compromise reproductive function but confer a transgenerational benefit to bone development in CD-1 mice.
9

Transgenerational Effects of Early Exposure to Soy Isoflavones on Reproductive Health and Bone Development in CD-1 Mice

Dinsdale, Elsa 23 August 2011 (has links)
Previous studies showed that early exposure to soy isoflavones resulted in improved bone mineral density (BMD) and bone quality that resulted in stronger bones in CD-1 mice. This study investigated whether the benefits to bone health are transferred to second generation (F2) females and if there are any adverse effects on reproductive health. First generation (F1) female CD-1 mice received subcutaneous injections of the isoflavones daidzein (DAI) and genistein (GEN) or corn oil from postnatal day (PND) 1 to 10 or 21. F1 and F2 treated-females experienced earlier pubertal onset and lengthened anogenital distance but only F1 had reduced fertility, histological abnormalities in the uterus and ovaries, and altered estrous cycling. F2 had higher BMD and stronger bones at 4 months of age. In conclusion, early life exposure to soy isoflavones compromise reproductive function but confer a transgenerational benefit to bone development in CD-1 mice.
10

Kindergarten Prevalence of Children with Special Needs in Ontario and Developmental Health Outcomes at School Entry and Grade 3

Noor, Salmi Tahseen January 2019 (has links)
Background: One in every nine school-age children in Ontario has special needs (SN) as a result of developmental disorders, however, the distribution of SN is unequal among schools. This prompted a group level exploration of the developmental health outcomes of typically developing children in schools with SN children. Methods: This study uses data from the Early Development Instrument (EDI; kindergarten measure of child development), administered in Ontario between 2010-2012, and neighbourhood-level socioeconomic status (SES) from the 2006 Canadian Census to examine associations between school SN prevalence and typically developing children’s development. Relationships between school SN prevalence and developmental health in those schools were explored in Grade 3 using Education, Quality and Accountability Office (EQAO) tests. Findings: Kindergarten multivariable regression model showed that school SN prevalence was associated with school level kindergarten vulnerability rates after controlling for SES and demographic factors. However, school SN prevalence was not a significant predictor of school performance in Grade 3 reading, writing and math test scores. Our exploration revealed that school kindergarten vulnerability rate, which was itself associated with the school prevalence of children with SN, was a stronger predictor of school Grade 3 academic outcomes than school SN prevalence after controlling for demographic and SES factors. Conclusions: This study provides a snapshot of population level inequalities in child health outcomes by demonstrating associations between school SN prevalence and kindergarten vulnerability, and kindergarten vulnerability and Grade 3 achievement. These findings further emphasize the importance of adequate early intervention programs in schools, and appropriate resource allocation for the health outcomes of typically developing children. / Thesis / Master of Health Sciences (MSc)

Page generated in 0.0324 seconds