Coming dissertations at MedFak
-
Exploring the Genetic Landscape of Chicken Populations : Admixture, Growth QTLs, and Long-Term Selection Dynamics
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-527022
This thesis analyzes the genetic structure of chicken populations across different breeding histories and environments. Genomic methodologies were used to uncover complex traits and domestication history over time. The work consists of three studies contributing to a broader understanding of chicken genetic diversity and the impact of selective breeding practices.
The first study delves into the global chicken population, using genome-wide analysis to uncover the intricate fine structure and historical admixture events that have shaped these populations. The research has unveiled significant connections between populations and pivotal breeding events, highlighting the complex relationships within chicken populations. This study offers intriguing insights into the genetic continuity and admixture patterns across diverse chicken breeds, from junglefowl to commercial lines.
The second study focuses on the genetic complexity within a specific quantitative trait locus (QTL) region known as Growth1, which is influential in chicken growth. This study, conducted using an advanced intercross line from the Virginia body weight line, identifies significant additive, haplotype, and epistasis effects within the Growth1 QTL region. The findings challenge simplistic genetic models by demonstrating the involvement of multiple loci in regulating body weight and contribute to understanding complex trait architecture.
The third study extends the investigation to the long-term effects of selection on chicken lines, providing a deeper understanding of the genetic mechanisms underlying selection responses. By mapping multiple additive QTLs associated with body weight compared with the GWA study results, several novel regions were determined and are still contributing to the selection response even after 40 generations of intense selection.
These different views provide practical insights into chickens' intricate genetic makeup. By analyzing their domestication history, genetic variation effects, and the population's response to selective breeding, we better understand one of the most important economic organisms for humans — the chicken. This understanding can potentially inform and improve selective breeding practices, leading to more efficient and sustainable poultry production.
-
Environmental exposures, body composition and pulmonary function : How can we improve diagnostics?
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-526832
Pulmonary diseases are influenced by numerous factors such as lifestyle, environment, genetics, and adipose tissue. A common factor for these diseases is that early and accurate diagnosis is beneficial for effective treatment. The improvement and development of diagnostic tools, including nanotechnology, offers the potential for more reliable diagnosis.
The main aim of this thesis was to improve our understanding of respiratory assessment through a comprehensive approach. This approach included studying the effectiveness of training and feedback in conducting spirometry tests to accepted diagnostic standard (paper I). Evaluating the association of body impedance analysis (BIA) and waist circumference in assessing the decline in lung function induced by excessive adipose tissue (paper II) and investigating the effects of weight change on lung function (paper III). In addition, the thesis investigated the potential of inhaled nano particles in individuals with impaired lung epithelium as a possible new diagnostic method (paper IV). Overall, these studies aimed to improve lung function diagnostics to make them more reliable, accessible and to advance the development of cutting-edge technological methods.
Our results show that the use of structured on-line feedback improve the quality of spirometry and that there is a potential gender differences in the effects of excess adipose tissue on lung function. Data also demonstrated a difference in clearance of inhaled nanoparticles between healthy and patients with impaired alveolar integrity, opening the possibility for new diagnostic approaches.
-
Aspects of generalised joint hypermobility on pelvic girdle pain and physical disability during and after pregnancy
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-526724
Pelvic girdle pain is common during pregnancy, but its multifactorial mechanisms are not completely understood. Generalised joint hypermobility is associated with musculoskeletal pain due to fragile connective tissue. The increased laxity of ligaments during pregnancy may be related to pelvic girdle pain. Women with fragile connective tissue may be more prone to developing pain during pregnancy. The overall aim was to examine whether generalised joint hypermobility increases the likelihood of experiencing pelvic girdle pain and physical disability during and after pregnancy. In Study I, the inter- and intra-rater reliability of joint mobility measurements in 49 adults were investigated, evaluating 12 joints. Study II explored the association between self-reported generalised joint hypermobility and pelvic girdle pain during pregnancy involving 2,217 women. In study III, the association between clinically assessed generalised joint hypermobility and pelvic girdle pain during and after pregnancy were examined, involving 356 women. Study IV focused on the development of physical disability from early pregnancy to nine months postpartum considering pelvic girdle pain, generalised joint hypermobility and overweight, and wheather the onset of pelvic girdle pain and the level of physical disability during pregnancy was associated with physical disability nine months postpartum. The findings in this thesis indicated good-to-excellent inter- and intra-rater reliability in most mobility measurements. Women who self-reported generalised joint hypermobility exhibited higher odds of experiencing pelvic-girdle pain, particularly in early pregnancy. Clinically assessed generalised joint hypermobility was associated with increased pain intensity in early pregnancy and, when combined with overweight, an increased risk of pelvic girdle pain. Physical disability increased during pregnancy irrespective of pelvic girdle pain status, but the overall prognosis was positive. Pelvic girdle pain had the strongest influence on disability, in contrast to generalized joint hypermobility and overweight. Early-onset pelvic girdle pain during pregnancy and a higher disability index during pregnancy were associated with physical disability nine months postpartum. Women experiencing pelvic girdle pain early in pregnancy may benefit from evaluation for generalised joint hypermobility, as they may experience more intense pain. It is crucial to develop methods for preventing and managing pelvic girdle pain, given its strong association with physical disability during and after pregnancy. Early-onset pelvic girdle pain and a higher disability index during pregnancy were predictors of physical disability nine months postpartum.