Social science genetics and fertility:Essays on the Interplay Between Genes, Social Environment and Human Fertility

To what extent do genes influence the age at which you have your first child and the number of children that you have? Does the social environment influence genetic effects on fertility? Do genes lead to spurious associations between life outcomes such as education and age at first birth? The social sciences have been slow to integrate a genetic approach to the study of fertility choice and behaviour, resulting in theories and findings that are largely socially deterministic. This dissertation investigates genetic and environmental influences on human fertility—as well as their interplay—using both twin data and molecular genetic data of more than 31,000 genotyped individuals from six countries.The central finding from this dissertation is that individual differences in fertility behaviour are associated with genetic differences: this implies ongoing natural selection in humans. However, it is also found that genetic variants associated with fertility can differ across countries and time. Taking the historical and geographic environment into account can increase the explanatory power of genes for fertility up to five times. A twin study shows that the association between education and the age at first birth is largely spurious due to family background effects—not genes. This casts doubt on the idea that the educational expansion in the second half of the 20th century is responsible for the strong fertility postponement all over Europe. Overall, the results demonstrate that an integrative research approach of social sciences and genetics generates important insights into human fertility

Win or go home?: Michigan soldiers view of the 1864 presidential election

Abraham Lincoln is one of the most revered Presidents in the history of the United States. Lincoln is remembered for ending slavery, ending the Civil War, and reconstructing the country after the atrocities of the Civil War. Despite his accomplishments, Lincoln was not the heroic icon during the Civil War he is today. Coming into the 1864 Presidential election, Lincoln\u27s reelection chances were dim due to the prolonged duration of the war and his views on emancipating the slaves. Further, public opinion in the Union was strictly divided into two views of the war: those who wanted peace and those who wanted to win the war and save the Union. However, in some circumstances the views of the public do not resonate with the views of soldiers. Did the soldiers want peace? Or did they want to bring victory to the Union? For the first time in Presidential politics, the soldiers had the opportunity to answer this question by casting ballots.1 The soldier vote in the 1864 election was sure to affect the race, and answer the questions posed above. The aim of this thesis is to focus on Michigan soldiers\u27 view of the 1864 Presidential election by looking at their views of Lincoln and his competitor, General George Britton McClellan, from New Jersey

Locating 1-D Bar Codes in DCT-Domain

Today\u27s digital cameras and camera phones allow users to capture bar codes, which are used to uniquely identify consumer product. In this paper a fast algorithm is proposed that locates a 1-D bar code in the DCT-domain of a bar code image taken by a digital camera. The algorithm uses the DCT-transform properties to distinguish bar code from other texture, morphological operations to smooth the detected bar code area and the features of the extracted area lo detect position and orientation of a bar code in the imag

Region segmentation for facial image compressing

This paper addresses the segmentation of passport images in order to improve quality of significant regions and to further reduce redundancy of insignificant ones. The approach is to first segment a facial image into two major regions, namely background and foreground. Here a new technique using pixel difference is presented. To compress facial regions at better quality, a face segmentation algorithm is introduced that detects eyes and mouth in a face. Region of interest (ROI) coding is then used to obtain better quality for facial features. At the end, some strategies that make use of region segmentation are proposed in order to increase performance in entropy codin

The Sociogenomics of Polygenic Scores of Reproductive Behavior and Their Relationship to Other Fertility Traits

Human reproductive behavior until relatively recently has been explained exclusively via individual and social characteristics. This article applies results from a recent Genome-Wide Association Study that combined sixty-two data sources to isolate twelve genetic loci associated with reproductive behavior. We create polygenic scores that allow us to include a summary variable of genetic factors into our statistical models. We use four datasets: the U.S. Health and Retirement Study, Dutch LifeLines, TwinsUK and the Swedish Twin register. First, we provide a brief overview of the dominant explanations of reproductive behavior. Second, we test the predictive power of polygenic scores. Third, we interrogate the robustness of our models using a series of sensitivity analyses to take into account possible confounders due to population stratification and selection

Social science genetics and fertility:Essays on the Interplay Between Genes, Social Environment and Human Fertility

To what extent do genes influence the age at which you have your first child and the number of children that you have? Does the social environment influence genetic effects on fertility? Do genes lead to spurious associations between life outcomes such as education and age at first birth? The social sciences have been slow to integrate a genetic approach to the study of fertility choice and behaviour, resulting in theories and findings that are largely socially deterministic. This dissertation investigates genetic and environmental influences on human fertility—as well as their interplay—using both twin data and molecular genetic data of more than 31,000 genotyped individuals from six countries.The central finding from this dissertation is that individual differences in fertility behaviour are associated with genetic differences: this implies ongoing natural selection in humans. However, it is also found that genetic variants associated with fertility can differ across countries and time. Taking the historical and geographic environment into account can increase the explanatory power of genes for fertility up to five times. A twin study shows that the association between education and the age at first birth is largely spurious due to family background effects—not genes. This casts doubt on the idea that the educational expansion in the second half of the 20th century is responsible for the strong fertility postponement all over Europe. Overall, the results demonstrate that an integrative research approach of social sciences and genetics generates important insights into human fertility

Strong light-matter coupling in organic microcavities : investigating the fundamental principles of strong coupling in strongly disordered materials experimentally

Strong light–matter coupling gives rise to intriguing possibilities like Bose-Einstein condensation at room temperature. In this context, organic semiconductors are particularly attractive because they combine large oscillator strengths with high exciton binding energies and thus readily enable large light–matter coupling strengths up to room temperature. Yet, in these commonly strongly disordered materials, the applicability of fundamental predictions developed for systems of high order needs to be verified. Hence, the validity of the theoretically predicted form of the coupling strength and of the coupled oscillator model is tested for strongly coupled organic microcavities in this thesis. Experimental investigations of metal-clad microcavities confirm the coupling strength to be proportional to the electric field with which the excitons interact and to the square root both of the oscillator strength of the material and of the number of chromophores inside the microcavity. Systematically varying these parameters demonstrates a non-zero threshold for the onset of the strong coupling regime for the first time, which confirms the applicability of the coupled oscillator model also for strongly disordered systems. Moreover, the effect of the coupling strength on the photoluminescence from organic microcavities is investigated. For metal-clad cavities, but not for microcavities with dielectric mirrors, an increase of the luminescence intensity with increasing coupling strength was found. For the latter system, a systematic study aimed to determine the properties of the cavity and of the organic material which are crucial for polariton lasing. However, experiments did not yield polariton lasing, for which two potential reasons are identified: (1) the vanishing of modes close to resonance and (2) pronounced bimolecular quenching in the studied material. Since organic microcavities are complex, systematic studies as presented in this thesis are an important step towards a more profound understanding of organic polaritons."This work was supported by the Engineering and Physical Sciences Research Council [grant number EP/L015110/1]" -- Acknowledgement