Structure of Number Theoretic Graphs

The tools of graph theory can be used to investigate the structureimposed on the integers by various relations. Here we investigate twokinds of graphs. The first, a square product graph, takes for its verticesthe integers 1 through n, and draws edges between numbers whose productis a square. The second, a square product graph, has the same vertex set,and draws edges between numbers whose sum is a square.We investigate the structure of these graphs. For square productgraphs, we provide a rather complete characterization of their structure asa union of disjoint complete graphs. For square sum graphs, we investigatesome properties such as degrees of vertices, connectedness, hamiltonicity,and planarity

AUSFTA and its implications for the Australian stock market

This paper investigates whether current and future domestic and United States macroeconomic variables can explain long and short run stock returns in Australia. This is undertaken with a view to examining the potential implications of the Australia-United States Free Trade Agreement (AUSFTA). America is included in the analysis as a “foreign influence”. In the recent past it has been Australia’s second largest trading partner after Japan. The long run relationship tested in this study is based on the present value model of stock prices, which is tested using a range of cointegration and causality tests. These include the Johansen ML test, Long Run Structural Modelling, a Vector Error Correction Model and Variance Decomposition. A present value model based on domestic and external economic variables is estimated for the Australian market. American economic activity does not currently have a significant influence on Australian stock markets in the long run and is less influential than domestic economic activity. However, we would expect this to become more significant in the future, as a result of the dismantling of trade barriers in financial services and investments which will be associated with the implementation of AUSFTA

Analysis of Drivers\u27 Head and Eye Movement Correspondence: Predicting Drivers\u27 Glance Location Using Head Rotation Data

The relationship between a driver’s glance pattern and corresponding head rotation is not clearly defined. Head rotation and eye glance data drawn from a study conducted by the Virginia Tech Transportation Institute in support of methods development for the Strategic Highway Research Program (SHRP 2) naturalistic driving study were assessed. The data were utilized as input to classifiers that predicted glance allocation to the road and the center stack. A predictive accuracy of 83% was achieved with Hidden Markov Models. Results suggest that although there are individual differences in head-eye correspondence while driving, head-rotation data may be a useful predictor of glance location. Future work needs to investigate the correspondence across a wider range of individuals, traffic conditions, secondary tasks, and areas of interest

Owl and Lizard: Patterns of Head Pose and Eye Pose in Driver Gaze Classification

Accurate, robust, inexpensive gaze tracking in the car can help keep a driver safe by facilitating the more effective study of how to improve (1) vehicle interfaces and (2) the design of future Advanced Driver Assistance Systems. In this paper, we estimate head pose and eye pose from monocular video using methods developed extensively in prior work and ask two new interesting questions. First, how much better can we classify driver gaze using head and eye pose versus just using head pose? Second, are there individual-specific gaze strategies that strongly correlate with how much gaze classification improves with the addition of eye pose information? We answer these questions by evaluating data drawn from an on-road study of 40 drivers. The main insight of the paper is conveyed through the analogy of an "owl" and "lizard" which describes the degree to which the eyes and the head move when shifting gaze. When the head moves a lot ("owl"), not much classification improvement is attained by estimating eye pose on top of head pose. On the other hand, when the head stays still and only the eyes move ("lizard"), classification accuracy increases significantly from adding in eye pose. We characterize how that accuracy varies between people, gaze strategies, and gaze regions.Comment: Accepted for Publication in IET Computer Vision. arXiv admin note: text overlap with arXiv:1507.0476

Activation of PmrA inhibits LpxT-dependent phosphorylation of lipid A promoting resistance to antimicrobial peptides

During its transport to the bacterial surface, the phosphate groups of the lipid A anchor of Escherichia coli and Salmonella lipopolysaccharide are modified by membrane enzymes including ArnT, EptA and LpxT. ArnT and EptA catalyse the periplasmic addition of the positively charged substituents 4-amino-4-deoxy-L-arabinose and phosphoethanolamine respectively. These modifications are controlled by the PmrA transcriptional regulator and confer resistance to cationic antimicrobial peptides, including polymyxin. LpxT, however, catalyses the phosphorylation of lipid A at the 1-position forming 1-diphosphate lipid A increasing the negative charge of the bacterial surface. Here, we report that PmrA is involved in the regulation of LpxT. Interestingly, this regulation does not occur at the level of transcription, but rather following the assembly of LpxT into the inner membrane. PmrA-dependent inhibition of LpxT is required for phosphoethanolamine decoration of lipid A, which is shown here to be critical for E. coli to resist the bactericidal activity of polymyxin. Furthermore, although Salmonella lipid A is more prevalently modified with l-4-aminoarabinose, we demonstrate that loss of Salmonella lpxT greatly increases EptA modification. The current work is an example of the complexities associated with the structural remodelling of Gram-negative lipopolysaccharides promoting bacterial survival

Clinical and Computational Collaboration in Orthopaedic Biomechanics

Computational Infrastructure and Informatics Poster SessionThe mission of the Comparative Orthopaedic Laboratory at the University of Missouri-Columbia (COL-UMC) is three-fold: 1.To design and conduct the highest quality hypothesis-driven research focused on orthopaedic disorders of . 2. To implement a comparative approach to investigation of joint disease in order to most efficiently and comprehensively address identified problem. 3. To apply basic science research to the clinical situation in order to span the gap that often limits the usefulness of scientific discoveries. The mission of the Musculoskeletal Biomechanics Research Laboratory (MBRL) at the University of Missouri - Kansas City is to: Discover, disseminate, and utilize knowledge pertaining to the loading of joint tissues during dynamic activity. The (COL-UMC) includes an internationally recognized team of scientists and clinicians while the MBRL, in conjunction with the UMKC Human Motion Laboratory, is comprised of biomedical engineers focused on musculoskeletal tissue mechanics and movement simulation. Collaboration between the two labs can provide great benefit for both research programs by combining clinical, computational, and experimental research efforts. The COL-UMC and the MBRL are currently working together on a Missouri Life Sciences Research Board funded project titled, ”Computational Simulation of Canine Biomechanically Induced Unicompartmental Osteoarthritis: a Concurrent Multiscale Approach”. This work combines the internationally recognized expertise in canine osteoarthritis and tissue engineering of the COL-UMC with the musculoskeletal biomechanics expertise and innovative multiscale modeling techniques of the MBRL. Osteoarthritis is a debilitating disease that is not completely understood, but evidence links the severity, progression, and treatment of the disease to the mechanical environment in the knee during everyday activities such as walking, running, and stair climbing. The natural response of articular cartilage to insult or injury is an outcome of complex interconnected factors that include anatomy, biology, and muscle forces. The goal of this project is to develop a predictive, computationally efficient, patient level simulation tool of mechanical osteoarthritis indicators. Specifically, the project is developing computational models of the canine knee that include surrogate models of cartilage tissue behavior. This model is then combined with neuromusculoskeletal models of movement and validated through in-vivo canine models of osteoarthritis. The project addresses a key area in osteoarthritis research that has largely been neglected, the role of muscles in osteoarthritis pathomechanics. Several engineering students from UMKC and medical students from UMC are working on the project and excellent progress has been made in the first year. Project work includes: 1) Mechanical testing to determine material properties of the canine menisci and articular cartilage 2) Magnetic Resonance Imaging and generation of hind limb bone, cartilage, ligament, muscle, and menisci geometries 3) Development of knee and musculoskeletal models of the hind limb 4) Meniscal release procedure to induce unicompartmental osteoarthritis 5)Gait testing at the UMKC Human Motion lab both pre-surgery and post-surgery 6) Hind limb testing to validate developed musculoskeletal models 7) Development of tissue level finite element models of cartilage indentation testing for tissue level surrogates