In an effort to better understand patterns of genetic variation in modern African populations, I surveyed nucleotide variability at four loci in five diverse sub-Saharan African populations. First, I analyzed the mitochondrial DNA (mtDNA) and the non-recombining portion of the Y chromosome (NRY), asking specifically if similar models of population size change could be fit to re-sequencing data from these two loci when examined in the same populations. Four tests of population growth were employed and results indicated that food-producing populations best fit a model of exponential growth for the mtDNA but not the NRY, and hunter-gathering populations best fit a model of constant population size for both mtDNA and the NRY. These results are likely due to sex-specific migration or differences in the effective population sizes of males and females.Next, I examined mtDNA and NRY population structure in these same populations, to assess the relative effects of migration and effective population size on patterns of mtDNA and NRY nucleotide variability. I used an Isolation with Migration (IM) model to disentangle estimates of effective population size and migration. Results indicated that levels of mtDNA population structure are higher than those of the NRY, and female migration tends to be unidirectional while that of males is largely bidirectional. I found that in food-producing populations, male migration rate estimates are in fact higher, not lower, than those of females, while estimates of male effective population size are strikingly small. I infered that males have experienced a period of population size reduction due to replacement, and that this most likely occurred during the Bantu expansions, approximately 5,000 years ago.Finally, I assessed population structure in these populations using a multilocus approach which estimated current and ancestral effective population sizes, migration rates, split times and fraction of the ancestral population that contributed to current populations. Current and ancestral effective population sizes ranged from ~5,000-8,000 individuals. Most populations showed an increase in size relative to the ancestral population. Population split times ranged from 17-142 thousand years (KYR); the Khoisan split times were the oldest and the Niger-Congo speaking populations' split times the most recent. Since the oldest population split times precede the dates for the earliest modern humans outside of Africa, I posited that modern humans likely evolved at a time when structured populations already existed in Africa.

Sex chromosomes and autosomes often differ in their relative rates of evolution, with sex chromosomes generally accumulating changes more rapidly (faster-X evolution). Transposable elements (TEs) make up a significant portion of eukaryotic genomes and are some of the most rapidly evolving genetic elements. We compared relative rates of insertion on the X and autosomes for 78 families found in Drosophila melanogaster. The average X/A ratio for these TE families was 1.11, similar to the mean dS X/A ratio, indicating no male-bias in mutation rate or TE insertion. The major mode of the distribution was ~0.8, indicating stronger purifying selection on the X chromosome for most TEs. We found no effect on X/A from sex-specific TE expression, but TEs with male-specific piRNA had an average X/A ratio of 0.62. We also found that TEs with very high X/A ratios (top 5%) had X chromosome insertions in areas of relative low recombination.

The overall objective of the research presented in this dissertation was to investigate molecular risk factors of susceptibility to estrogenic chemicals, polychlorinated biphenyls (PCBs), hormone replacement therapy, and oral contraceptives and how that leads to the development of pulmonary arterial hypertension (PAH). Environmental and molecular risk factors for PAH are not clearly understood. This is a major hurdle for the development of new therapy against PAH as well as understanding individual susceptibility to this disease. Gender has been shown to impact the prevalence of PAH. Although controversial, estrogens have been implicated to be a risk factor for PAH. Thus, we hypothesize that women exposed to estrogenic chemicals are at increased risk of developing PAH when endocrine disrupting chemicals interact with unopposed estrogen to worsen pulmonary arterial disease. In support of this hypothesis, we have accomplished the following: Microarray data on PAH were collected and subsequent meta-analysis was conducted using genome-wide association and environment-wide association approaches on published studies as well as GEO and NHANES data. All PCB geometric mean concentrations found higher levels in people at risk of PAH than people not at risk of PAH. The sum of non-dioxin-like PCBs and the sum of dioxin-like PCBs were significantly higher in people at risk of PAH than people not at risk of PAH. Also, different levels of LOD (including PCBs concentration >LOD, > 50th percentile, 50th-75th percentile, and ≥75th percentile) were significantly higher in people at risk of PAH than people not at risk of PAH. We reported that females used estrogen pills and oral contraceptive were associated with risk of PAH. However, females used progestin and estrogen/progestin pills were not at risk of PAH. Molecular risk factor analysis using machine learning approaches revealed that VAMP2, LAMA5, POLR2C, VEGFB, and PRKCH genes are causal genes of PAH pathogenesis. Gene ontology and pathway analysis of PAH showed that genes involved in the apoptosis pathway, p53 pathway, Ras Pathway, T-cell activation, TGF-beta pathway, VEGF pathway, and Wnt pathway appear to be significantly associated with PAH. Documenting the exposure to estrogenic chemicals among the general U.S. population, and identifying agents and molecular risk factors associated with PAH have the potential to fill research gaps and facilitate our understanding of the complex role environmental chemicals play in producing toxicity in the lungs.

Recent research on girls in science education in Australian primary schools indicates a participation rate lower than that of boys. This inequality could lead subsequently to reduced opportunities for girls entering the workforce in their adult years. Many studies have attempted to reveal why this situation has arisen and a variety of strategies for increasing girls' participation has been suggested. A relatively new strategy that does not appear frequently in the research literature is the use of educational computer game software. An important question arises: does the game software used in primary school science education reflect design attributes favoured by boys and, if so, do these attributes actively discourage girls' participation by making them feel uncomfortable or stressed? My case study was designed to identify design features of computer games that girls prefer so that these features can be included in educational computer game software designed for science education, as well as the other Key Learning Areas. Through interviews, surveys and observations my interpretive study obtained the opinions and views of over 200 children in two suburban Australian primary schools in which I work as a teacher-librarian. In this role I purchase educational computer games and organize special classes for students to play them. From my analysis of the data I make recommendations that reflect girls' preferred design attributes for educational computer games. I also generate a checklist of criteria from my interpretations that may result in the purchase of software that could not only enhance girls' participation and success in primary school science, the curriculum area of greatest personal interest to me, but also in other Key Learning Areas of primary education.\

<p>Faces constitute one of the most important stimuli for humans. Studies show that women recognize more faces than men, and that females are particularly able to recognize female faces, thus exhibiting an own-sex bias. In the present thesis, three empirical studies investigated the generality of sex differences in face recognition and the female own-sex bias. <i>Study I</i> explored men’s and women’s face recognition performance for Bangladeshi and Swedish female and male faces of adults and children. Result showed sex differences, favoring women, for all face categories. <i>Study II </i>assessed boys’ and girls’ ability to recognize female and male faces from two age- and ethnic groups. The result demonstrated that girls recognize more faces than boys do, but that no sex differences were present for Swedish male faces. The results from <i>Study I</i> and <i>II</i> consistently demonstrate that females show reliable own-sex biases independent of whether the female faces were young, old, or of Bangladeshi or Swedish origin. In an attempt to explain the mechanisms of sex differences in face recognition and the female own-sex bias, <i>Study III</i> investigated men’s and women’s recognition performance for androgynous faces, either labeled “men”, “women”, or “faces”. The result showed that women told to remember “women” recognized more faces than women told to remember faces labeled “men” or “faces”, and that sex differences were present for androgynous faces, regardless of the label. Based on these findings, it is suggested that females’ attention is in particular directed towards other females, resulting in an own-sex bias. It is also suggested that there may be a difference in females’ and males’ orientation toward other individuals. This difference can have a biological base, which together with socialization may result in sex differences in face recognition. </p>

Faces constitute one of the most important stimuli for humans. Studies show that women recognize more faces than men, and that females are particularly able to recognize female faces, thus exhibiting an own-sex bias. In the present thesis, three empirical studies investigated the generality of sex differences in face recognition and the female own-sex bias. Study I explored men’s and women’s face recognition performance for Bangladeshi and Swedish female and male faces of adults and children. Result showed sex differences, favoring women, for all face categories. Study II assessed boys’ and girls’ ability to recognize female and male faces from two age- and ethnic groups. The result demonstrated that girls recognize more faces than boys do, but that no sex differences were present for Swedish male faces. The results from Study I and II consistently demonstrate that females show reliable own-sex biases independent of whether the female faces were young, old, or of Bangladeshi or Swedish origin. In an attempt to explain the mechanisms of sex differences in face recognition and the female own-sex bias, Study III investigated men’s and women’s recognition performance for androgynous faces, either labeled “men”, “women”, or “faces”. The result showed that women told to remember “women” recognized more faces than women told to remember faces labeled “men” or “faces”, and that sex differences were present for androgynous faces, regardless of the label. Based on these findings, it is suggested that females’ attention is in particular directed towards other females, resulting in an own-sex bias. It is also suggested that there may be a difference in females’ and males’ orientation toward other individuals. This difference can have a biological base, which together with socialization may result in sex differences in face recognition.

The present monograph deals with the problem of sex differences in test results from various angles. Initially, the aim was to investigate whether the use of test results in selection could be considered fair in spite of sex differences in test score averages. As work progressed, the aim was specified towards clarifying in what manner test item content is related to sex differences in results and whether the observed differences are consistent over different groupé of men and women. After a brief review of some research results on sex differences in cognitive abilities, the Swedish Scholastic Aptitude Test (SSAT) is described. The SSAT is the measuring instrument in the following empirical studies. In chapter four there is a survey of a number of models which aim at correcting for unfair group differences in test scores when the tests are to be used in selection. Two models are examined empirically. In chapter five such models are examined that aim to identify individual test items giving deviant results. The conclusion of these two studies is that statistical models can not solve the problem of group differences in test scores, since what constitutes fairness is mainly a value problem. This cannot be dealt with in a strictly technical manner. Chapter six is devoted to analyses of test item content and sex differences in all subtests on vocabulary and general knowledge which have been used in the SSAT between 1977 and 1983. The conclusion from these analyses is that test item content seems to determine whether men or women obtain higher test scores. Some subcategories of items seem to favour men and others favour women. The extent to which the testees are able to predict which items favour one sex or the other is studied in chapter seven. The testees could only make appropriate judgements to a very limited extent. In chapter eight the significance of age and education for sex differences in test scores is studied. Furthermore, sex differences on individual items are studied for men and women having the same score on the subtest level. Sex differences in scores on individual test items could not be eliminated by equalizing age, education or subtest achievement respectively. Finally, the results from all the studies are summarized and discussed in view of their significance for the validity of the tests. / digitalisering@umu

Dietary restriction (DR), is a reduction in food intake, either through overall calorie or specific macronutrient intake, while avoiding malnutrition. DR has been consistently shown to increase longevity and protect against age related diseases. Although originally thought to be the result of a reduction in caloric intake, recent evidence suggests that the ratio of macronutrients, particularly that of protein : non-protein energy, also plays a role. The broad range of species in which DR is known to be effective, suggests an evolutionary conserved mechanism. However, the suggestion of a strong model species bias and a potential sex bias have led some to question the ubiquity of responses to DR. Here, I address the following questions: (i) How consistent is the effect of DR on reproduction? (ii) How does varying macronutrient intake effect both growth and body composition in three-spine sticklebacks (Gasterosteus aculeatus)? (iii) What is the effect of dietary macronutrient intake on lifespan and reproduction in the three-spine stickleback? and (iv) How does changing macronutrient intake impact fitness related traits, such as condition and performance in three-spine sticklebacks? Through use of a systematic review and meta-analysis, I show that the effect of DR on reproduction is evolutionarily conserved, though the effect is stronger in model species. However, when accounting for all significant moderators there is no evidence of the suggested sex differences in the effect of DR. I show that body composition is predicted by dietary lipid intake, with sticklebacks targeting a lower ratio of protein : fat within the body, potentially via metabolism and excretion of protein. These results hint at a link between conversion and excretion of protein and survival costs associated with high protein diets. I show that mortality risk is reduced at balanced protein : lipid intakes in males and generally at low protein : lipid intakes for females. However, the effect in females is not consistent throughout life. I further show that reproduction is maximised on high protein : lipid intakes for both sexes. These results suggest a macronutrient mediated trade-off between lifespan and reproduction in male three-spine sticklebacks. Finally I show a positive effect of lipid intake on male condition (a possible indicator of overall health) hinting at a relationship between lipid intake, adiposity, health and lifespan in male three-spine sticklebacks.

This investigation examines how knowledge of a researcher's intent, as well as gender, influences the clinical judgments of mental health professionals in sex role research. Conscious awareness of the study's aim was manipulated by varying experimental instructions to minimize (not salient) or maximize (salient) sex role awareness. Subjects were mental health professionals who rated a protocol of a female or male pseudopatient exhibiting masculine, and lacking feminine, stereotyped behaviors. It was hypothesized that if sex biases affect judgments, more negative ratings should be assigned to a female with cross sex role behavior than to male-appropriate role behavior. Differences should be greater when subjects were unaware of the nature of the study.

No description available.