Methodological challenges in pregnancy pharmacoepidemiology : the case of antiseizure medication and offspring neurodevelopment

This thesis is driven by the overarching aim of elucidating methodological challenges inherent in pharmacoepidemiology during pregnancy, with a particular focus on antiseizure medications. In Study I, a substantial surge in antiseizure medication use in the United Kingdom is observed, notably linked to increases in psychiatric indications. This shift in the medication landscape raises questions about the predominant contributors to this rise and underscores the necessity of understanding evolving patterns in drug utilization during pregnancy. In Study II, a large-scale examination of associations between specific antiseizure medications and neurodevelopmental conditions across Sweden and the United Kingdom emphasizes the importance of considering drug classes and shared confounders, providing valuable insights into the possible causal effect of these drugs. Study III explores the intricate interplay between epilepsy and psychiatric conditions, unveiling a heightened risk of neurodevelopmental conditions in individuals diagnosed with epilepsy. These findings shed light on the complex within-individual links between these conditions, potentially explaining the observed higher likelihood of neurodevelopmental diagnoses in children of women using antiseizure medications in pregnancy. In Study IV, a critical evaluation of drug safety studies warns against indication-based sampling, advocating for comprehensive regression adjustments to mitigate biases. Finally, Study V introduces the marginalized between-within model, a novel approach to derive absolute measures of occurrence in sibling analysis, enhancing the interpretability of findings. This thesis, collectively, calls for a concerted effort to improve the methodology of pharmacoepidemiology during pregnancy, fostering a more nuanced understanding of medication risks, and ultimately enhancing maternal and fetal health outcomes

Hyperk\"ahler Arnold Conjecture and its Generalizations

We generalize and refine the hyperk\"ahler Arnold conjecture, which was originally established, in the non-degenerate case, for three-dimensional time by Hohloch, Noetzel and Salamon by means of hyperk\"ahler Floer theory. In particular, we prove the conjecture in the case where the time manifold is a multidimensional torus and also establish the degenerate version of the conjecture. Our method relies on Morse theory for generating functions and a finite-dimensional reduction along the lines of the Conley-Zehnder proof of the Arnold conjecture for the torus.Comment: 13 page

Gain-assisted slow to superluminal group velocity manipulation in nano-waveguides

We study the energy propagation in subwavelength waveguides and demonstrate that the mechanism of material gain, previously suggested for loss compensation, is also a powerful tool to manipulate dispersion and propagation characteristics of electromagnetic pulses at the nanoscale. We show theoretically that the group velocity in lossy nano-waveguides can be controlled from slow to superluminal values by the material gain and waveguide geometry and develop an analytical description of the relevant physics. We utilize the developed formalism to show that gain-assisted dispersion management can be used to control the transition between ``photonic-funnel'' and ``photonic-compressor'' regimes in tapered nano-waveguides. The phenomenon of strong modulation of group velocity in subwavelength structures can be realized in waveguides with different geometries, and is present for both volume and surface-modes.Comment: Some changes in the abstract and Fig.1. No results affecte

Identifying functional relationships within sets of co-expressed genes by combining upstream regulatory motif analysis and gene expression information

Existing clustering approaches for microarray data do not adequately differentiate between subsets of co-expressed genes. We devised a novel approach that integrates expression and sequence data in order to generate functionally coherent and biologically meaningful subclusters of genes. Specifically, the approach clusters co-expressed genes on the basis of similar content and distributions of predicted statistically significant sequence motifs in their upstream regions

Facilitating Organizational Adoption of Sensor-Based Systems: Espoused Beliefs, Shared Assumptions and Perceived Values

The advent of sensor-based systems with their ability to collect, transmit and process context-aware data creates new opportunities for service delivery. We know from earlier research that there may be barriers to the adoption of new information technology (IT) within an organization. Sensor-based systems, with unprecedented potential for monitoring of products, people and processes are an interesting mix of potential and risk. Through the lens of organizational culture theory, we examine the question: Given the ambiguity and complexity of sensor-based systems, how does organizational culture influence perceptions of system value and purpose, and which factors determine the susceptibility of adoption among individual workers and teams? Our results suggest that the adoption of sensor-based systems is facilitated by 1) a basic comprehension of the system, its functionality, purpose and limitations; 2) a shared view of stakeholders’ roles and responsibilities, and 3) a pronounced and tangible vision for value creation

Boundary hopping and the mobility edge in the Anderson model in three dimensions

It is shown, using high-precision numerical simulations, that the mobility edge of the 3d Anderson model depends on the boundary hopping term t in the infinite size limit. The critical exponent is independent of it. The renormalized localization length at the critical point is also found to depend on t but not on the distribution of on-site energies for box and Lorentzian distributions. Implications of results for the description of the transition in terms of a local order-parameter are discussed