Manifolds (Mathematics) Geodesics (Mathematics) Space and time.
We investigate weak and strong refocusing of light rays in a space-time and related concepts. A strongly causal space-time ( X^ n +1 , g ) is emphstrongly refocusing at x ∈ X if there is a point y ≠ x such that all null-geodesics through y pass...
As the human population increases, it is imperative that we develop strategies to improve agricultural productivity to meet the growing demand for food, fuel and fiber. More than 2 billion people suffer from "hidden hunger" (a lack of essential...
Visual pigments. ; Cellular signal transduction. ; Rhodopsin. ; G proteins. ; Phosphorylation. ; Photoreceptors. ; Retinal degeneration.
Arrestins are regulatory proteins that participate in the termination of G protein-mediated signal transduction. The major arrestin in the Drosophila visual system, Arrestin 2 (Arr2), has been demonstrated to be essential for the termination of the...
There are no Vassiliev invariants of degree one for classical knots. A. Henrich proved the existence of a sequence of three Vassiliev invariants of degree one for virtual knots. The invariants get stronger and stronger, and the final invariant is...
Networks that model relationships in the real world have attracted much attention in the past few years. The "link prediction problem" plays a central role in the network area. In this thesis, we explore the link prediction problem in a...
In the Firefighter Problem, a fire starts at a vertex of a graph, and in discrete time units, it spreads from burned vertices to their neighbors, unless they are protected by one of the f firefighters that are deployed every turn. Once burned or...
For a local field K, we study the affine buildings Ξ n and Δ n naturally associated to SL n ( K ) and Sp n ( K ), respectively. Since Sp n ( K ) is a subgroup of SL 2 n ( K ), we investigate properties of a natural embedding of Δ n in Ξ 2 n ....
Thermodynamics, and the classic balance between entropy and enthalpy, provides a proverbial zoo of exotic phase behaviour that chemists can harness to create new materials out of simple liquids and polymers. The diversity of self-assembling...
Nanoparticles have made significant advances in recent years in the realm of cancer therapy. These nanoparticles typically range in size from 10-250nm in diameter, allowing for differential systemic-based biodistribution. The enhanced permeability...
We begin with a result on the refocussing of null geodesics in space-times. We show that all oriented refocussing 2-dimensional Lorentz manifolds are also strongly refocussing. We also introduce a theory of virtual Legendrian knots. We show that...
Annual screening mammograms are recommended for all women above 40 years of age for early detection of breast cancer, and are known to improve cancer mortality rates. However, mammography is hampered by low sensitivity and a high rate of false...
Constructibility (Set theory). Trees (Graph theory).
This thesis investigates possible initial segments of the degrees of constructibility. Specifically, we completely characterize the structure of degrees in generic extensions of the constructible universe L via forcing with Souslin trees. Then we...
This thesis contains material relating to two separate subjects. The first section determines when the C*-algebra affiliated to a directed graph has continuous trace. We use groupoid methods and the focus is on producing conditions on a graph that...
At the heart of computer games and computer generated films lies 3D content creation. A student wanting to learn how to create and edit 3D meshes can quickly find thousands of videos explaining the workflow process. These videos are a popular...
Nerve growth factor (NGF), the prototypic neurotrophin, is well characterized for its pro-survival and growth effects in sympathetic and sensory neurons. Acting as a target-derived factor, NGF regulates the maturation of innervating neurons, and...
Liver disease of different etiologies confers significant morbidity and mortality and hence it constitutes a major health concern worldwide. Stemming from a range of causes, such as viral, drug-induced, alcoholic, or autoimmune, the rate of...
This thesis constitutes the first steps in the author's program to investigate the question of when a homotopy of 2-cocycles ω = {ω[subscript t]}[subscript t∊[0,1]] on a locally compact Hausdorff groupoid Ɠ induces an isomorphism of the...
The focus of this thesis is the study of nuclearity and exactness for groupoid crossed product C*-algebras. In particular, we present generalizations of two well-known facts from group dynamical systems and crossed products to the groupoid setting....
In the past few years there has been a tremendous growth in the usage of digital images. Users can now access millions of photos, a fact that poses the need of having methods that can efficiently and effectively search the visual information of...
We present aligned hierarchies, a novel solution to the dimension reduction problem, representing high-dimensional and noisy sequential data as a low-dimensional object that encodes relevant information. In this thesis, we motivate our presentation...
In the nervous system, neuronal communication relies critically on the function of membrane ion channels. One of these is the voltage-gated sodium channel (VGSC), which is essential for the generation and propagation of action potentials in...
Chemical sensing and separation is a constant challenge intriguing many scientists. Through numerous efforts, revolutionary techniques and innovative materials have been successfully developed to solve this old problem. However, a practical but...
Candida albicans is a fungal species that naturally exists as a commensal member of the human microbiota, but can assume a pathogenic lifestyle and subsequently induce life-threatening systemic infections. The ability of the fungus to grow in...
We prove the existence of nontrivial multiparameter isospectral deformations of metrics on the classical compact simple Lie groups SO (n) (n = 9, n ≥11), Spin(n) (n = 9, n ≥11), SU (n) (n ≥7), and Sp (n) (n ≥5). The proof breaks into three...
Solar (Computer architecture). ; Ubiquitous computing. Sensor networks. ; Detectors. ; User interfaces (Computer systems).
The complexity of developing context-aware pervasive-computing applications calls for distributed software infrastructures that assist applications to collect, aggregate, and disseminate contextual data. In this dissertation, we present a Context...
Angiogenesis is part of the natural defense mechanism in brain against hypoxia and ischemia. Animal models and methods for the non-invasive investigation of cerebral angiogenesis are needed. This thesis addresses the hypothesis that steady state,...
Polynomials. Finite fields (Algebra). Algebraic functions. Number theory.
The ring of univariate polynomials over a finite field shares many foundational arithmetic properties with the ring of rational integers. This similarity makes it possible for many problems in elementary number theory to be translated 'through the...
A nocturnal activity pattern is central to almost all hypotheses on the adaptive origins of primates but this view has been challenged recently on the basis of variation in the cone opsin genes of nocturnal primates. The diversity among primates in...