Background: Recent research indicates that inadequate vitamin D status may incur increased cancer risk, particularly for breast and colon cancer. Cutaneous generation of vitamin D through direct absorption of summer sunlight is considered the principal source of vitamin D; however, at latitudes above 40ºN, UVB rays are insufficient to permit cutaneous synthesis during winter. Vitamin D can also be obtained from natural and fortified dietary sources and through supplement use, although dietary reference intake values do not seem to compensate for restricted cutaneous synthesis in winter. Objectives: To determine the prevalence of vitamin D insufficiency post-winter and post-summer, to determine the seasonal variation in 25-hydroxyvitamin D (25(OH)D) levels, and to investigate determinants of 25(OH)D concentrations. Methods: A cross-sectional study of vitamin D status post-winter and post-summer was conducted among 49 premenopausal rotating shift nurses at Kingston General Hospital. In each season, vitamin D levels were measured using a radioimmunoassay to quantify serum 25(OH)D from fasting blood samples, and personal, lifestyle, and dietary factors potentially influencing vitamin D levels were assessed from a self-report questionnaire. Nurses were classified as vitamin D sufficient (>30ng/mL) or insufficient (≤30ng/mL). Results: A statistically significant difference was found between mean serum 25(OH)D concentrations post-winter (32.6ng/mL) and post-summer (42.5ng/mL) (p=0.0003). The prevalence of vitamin D insufficiency post-winter was 49% compared to 24% post-summer p=0.02). Tanning bed use was associated with significantly higher winter serum 25(OH)D levels was tanning bed, while controlling for age, BMI, and vitamin D-fortified yogurt consumption (R2=0.41, p=0.007). For summer, predictors of higher serum 25(OH)D levels were supplement use and tanning bed use in the past six months, while controlling for age, BMI, and beef/veal consumption (R2=0.53, p=0.001). Conclusions: Vitamin D insufficiency was prevalent both post-winter and post-summer, but with much higher prevalence post-winter. Controlling for age and BMI, tanning bed use was a determinant of serum 25(OH)D concentrations in both seasons, while fortified yogurt consumption also contributed in winter, and beef/veal consumption and supplement use contributed in summer. These findings support the need to improve vitamin D status among this population, and to increase the dietary reference intake values and supplement recommendations. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2009-09-22 15:35:27.652

Evidence for the repeated, independent evolution of hot- and cool-season breeding populations across colonies of the Band-rumped Storm-petrel has garnered much interest from seabird ecologists and evolutionary biologists, alike. Sympatric seasonal populations have been shown to be each other’s closest relatives, implying that ecological divergence into two seasonal foraging types has taken place several times independently across the species’ range, each time in the absence of geographical barriers to gene flow. I present data on the molecular genetic characteristics of a unique year-round breeding population in the Cape Verde archipelago. Using mitochondrial control region sequence and five microsatellite loci, I characterized genetic relationships among 220 birds breeding in four different months (January, April, June and November) and tested for a relationship between temporal isolation and genetic differentiation. Birds breeding in April, June and November were genetically indistinguishable at microsatellite loci, but control region sequence suggested differentiation between January and other months (pairwise ΦST from 0.19 to 0.46, p≤0.05). No evidence for genetic isolation by time was found. A comparison of birds breeding in June and November revealed significant differences in a suite of morphological traits related to foraging strategy (tarsus length, bill length, bill depth, head length, wing length and tail shape), and even significant variation among birds breeding in the same month, despite evidence for gene flow between these groups. Interpreting these patterns in the context of Band-rumped Storm-petrel populations range-wide, I suggest that divergent selection on standing variation within ancestral populations may be an important mechanism explaining the repeated, independent evolution of conserved seasonal foraging types in this species. / Thesis (Master, Biology) -- Queen's University, 2011-02-28 12:02:44.256

No description available.

No description available.

The number of species varies greatly among taxa. In birds, for example, the parvorder Passerida contains 3556 species while the Odontophorida (New World Quails) contains only six species. This uneven distribution of species among avian taxa is not random and therefore warrants an explanation. The behavioral drive hypothesis stipulates that the capacity for innovation, coupled with the rapid transmission of the behavioral novelty to conspecifics, may expose individuals to new selective pressures and help fix mutations that would otherwise not be expressed. This should lead to accelerated rates of evolution. I test this hypothesis by examining the link between behavioral flexibility and the number of species per taxon. I adopt a comparative approach and seek a general explanation of richness, thereby removing the traditional focus placed on the success of the songbirds and on their complex singing apparatus. I use two measures of flexibility, feeding innovation rate and relative brain size. (Abstract shortened by UMI.)

Sex-specific growth analyses were conducted for 32 nestling ospreys (Pandion haliaetus) in a migratory population in Nova Scotia, Canada and for 31 nestling ospreys in a sedentary population in Sonora, Mexico. Eight variables including weight, body components and plumage characteristics were measured to document the influence of sex on growth performance. Within populations, males differed significantly from females in having lower weight and body component asymptotes but did not differ in plumage characteristics or growth rates. There was no difference in growth performance between individuals in broods of various sizes or within broods as a result of hatching order asynchrony. Comparisons of geographic variation showed that sedentary ospreys in Mexico had significantly higher weight and tarsus asymptotes, reduced growth rates, longer nestling periods and later emergence of flight feathers than migratory ospreys. Individual nestlings were initially identified by sex from karyotypic analysis of fibroblast tissue collected from a sample of 31 nestlings in the field. The karyotype is presented and growth performance is discussed within the framework of evolutionary theory.

The following thesis reports on an investigation of the attitudes of allophone children and their teachers towards different French accents. Using the matched guise technique, a total of 108 children in grades 4, 5 and 6 (5 groups) evaluated samples of French spoken with a standard accent, a standard Quebec accent, an informal Quebec accent and a foreign accent. The pupils evaluated the accents based on eight criteria related to linguistic, professional and personal characteristics. Secondly, sub-groups from each class participated in a post-experimental discussion about the accents they had heard. The children's teachers were also interviewed privately, in order to give their opinions about the accents, and share their vision of an oral model for these allophone children attending French language schools in Montreal. Findings suggest a strong preference for standard accents, which is confirmed by the analysis of the post-experimental discussions.

Forest fragmentation poses a serious danger to population diversity in plants and animals by increasing species isolation, thus reducing the population size and genetic diversity. However, little information is available concerning how fragmentation impacts plant diversity. AFLP fingerprinting was used to assess genetic diversity within and between populations of Asarum canadense L. (Canadian Wild Ginger) across 11 different populations in East-Central Indiana. AFLP fingerprints using two primer pairs generated 51 distinct bands with an average of 25.5 bands per primer. Forty-eight low molecular weight distinct polymorphic bands were observed (50-200 bp range). The percentage of polymorphism was low (0-25%) indicating low levels of genetic diversity within each population studied. NTSYSpc Numerical Taxonomy Analysis Software generated aphenogram that revealed high levels of homologies within populations (75-100%), with individuals from the same population typically clustered. The genetic diversity between populations ranged from 10-50%. The populations from Jay, Randolph and Henry Counties clustered together exhibiting -54% homology, while populations from Mien, Madison, and Huntington counties shared approximately 64% homology. The populations from Adams, Blackford, Delaware, and Grant counties shared approximately 66% homology. However, within this last group Blackford and Delaware counties shared 90% homology. There were no apparent effects of the size of the forest fragments on the observed diversity measures. A possible relationship between genetic diversity and spatial distance was observed between populations moving from east to west. Possible reasons for this observation may be due to forest types, age of forests, climatic factors, soil types, and/or anthropogenic activities. Overall, the low level of average diversity within the populations strongly suggests that the individuals inhabiting isolated forests primarily propagate by asexual means.Ball State UniversityMuncie, IN 47306 / Department of Biology

A series of experiments was completed in which the morphology, anatomy and biochemistry of two Melilotus species, Melilotus alba and Melilotus officinalis, were studied. The purposes of the study were to illustrate whether the variability of specimens was due to polymorphism or speciation and to isolate the factors that have separated these specimens as competitors.The effects of impaction and scarification on the germination of M. alba and M. officinalis seeds were studied, as were the effects of light and temperature stimuli on germination and growth The rate of plant maturation and the chronology of flowering for the two species were investigated. Maturation differences were minor, but the chronologies of flowering deviated markedly.The techniques of one- and two-directional thin layer chromatography were used to separate the free amino acids in Melilotus seed extract preparations. The technique of polyacrylamide gel electrophoresis was used to separate the proteins in these preparations. In every experiment, the two Melilotus "species" were genus specific with no species variables in terms of the amino acid and protein complements.

The emerging field of personalized medicine and the prediction of side effects experienced due to pharmaceutical drugs is being studied intensively in the post genomic era. The molecular basis of inheritance and disease susceptibility is being unravelled, especially through the use of rapidly evolving new technologies. This in turn facilitates analyses of individual variations in the whole genome of both single subjects and large groups of subjects. Genetic variation is a common occurrence and although most genetic variations do not have any apparent effect on the gene product some do exhibit effects, such as an altered ability to detoxify xenobiotics. The human body has a highly effective detoxification system that detoxifies and excretes endogenous as well as exogenous toxins. Numerous studies have proved that specific genetic variations have an influence on the efficacy of the metabolism of pharmaceutical drugs and consequently the dosage administered. The primary aim of this project was the local implementation and assessment of two different genotyping approaches namely: the Applied Biosystems SNaPshot technique and Affymetrix DMET microarray. A secondary aim was to investigate if links could be found between the genetic data and the biochemical detoxification profile of participants. I investigated the approaches and gained insight into which method would be better for specific local applications, taking into consideration the robustness and ease of implementation as well as cost effectiveness in terms of data generated. The final study cohort comprised of 18 participants whose detoxification profiles were known. Genotyping was performed using the DMET microarray and SNaPshot techniques. The SNaPshot technique was used to genotype 11 SNPs relating to DNA repair and detoxification and was performed locally. Each DMET microarray delivers significantly more data in that it genotypes 1931 genetic markers relating to drug metabolism and transport. Due to the absence of a local service supplier, the DMET - microarrays were outsourced to DNALink in South Korea. DNALink generated raw data which was analysed locally. I experienced many problems with the implementation of the SNaPshot technique. Numerous avenues of troubleshooting were explored with varying degrees of success. I concluded that SNaPshot technology is not the best suited approach for genotyping. Data obtained from the DMET microarray was fed into the DMET console software to obtain genotypes and subsequently analysed with the help of the NWU statistical consultation services. Two approaches were followed: firstly, clustering the data and, secondly, a targeted gene approach. Neither of the two methods was able to establish a relationship between the DMET genotyping data and the detoxification profiling. For future studies to successfully correlate SNPs or SNP groups and a specific detoxification profile, two key issues should be addressed: i) The procedure for determining the detoxification profile following substrate loading should be further refined by more frequent sampling after substrate loading. ii) The number of participants should be increased to provide statistical power that will enable a true representation of the particular genetic markers in the specific population. The statistical analyses, such as latent class analyses to cluster the participants will also be of much more use for data analyses and interpretation if the study is not underpowered. / Thesis (M.Sc. (Biochemistry))--North-West University, Potchefstroom Campus, 2011.