Preparing Information Literate Teachers: A Review of the Literature

Ye

Preparing Information Literate Teachers: A Review of the Literature

Ye

Analysis of spatial point patterns on surfaces

With the advent of improved data acquisition technologies more complex spatial datasets can be collected at scale meaning theoretical and methodological developments in spatial statistics are imperative in order to analyse and generate meaningful conclusions. Spatial statistics has seen a plethora of applications in life sciences with particular emphasis on ecology, epidemiology and cell microscopy. Applications of these techniques provides researchers with insight on how the locations of objects of interest can be influenced by their neighbours and the environment. Examples include understanding the spatial distribution of trees observed within some window, and understanding how neighbouring trees and potentially soil contents can influence this. Whilst the literature for spatial statistics is rich the common assumption is that point processes are usually restricted to some d-dimensional Euclidean space, for example cell locations in a rectangular window of 2-dimensional Euclidean space. As such current theory is not capable of handling patterns which lie on more complex spaces, for example cubes and ellipsoids. Recent efforts have successfully extended methodology from Euclidean space to spheres by using the chordal distance (the shortest distance between any two points on a sphere) in place of the Euclidean distance. In this thesis we build on this work by considering point processes lying on more complex surfaces. Our first significant contribution discusses the construction of functional summary statistics for Poisson processes which lie on compact subsets of Rd which are off lower dimension. We map the process from its original space to the sphere where it is possible to take advantage of rotational symmetries which allow for well-defined summary statistics. These in turn can be used to determine whether an observed point patterns exhibits clustered or regular behaviour. Partnering this work we also provide a hypothesis testing procedure based on these functional summary statistics to determine whether an observed point pattern is complete spatially random. Two test statistics are proposed, one based on the commonly used L-function for planar processes and the other a standardisation of the K-function. These test statistics are compared in an extensive simulation study across ellipsoids of varying dimensions and processes which display differing levels of aggregation or regularity. Estimates of first order properties of a point process are extremely important. They can provide a graphical illustration of inhomogeneity and are useful in second order analysis. We demonstrate how kernel estimation can be extended from a Euclidean space to a Riemannian manifold where the Euclidean metric is now substituted for a Riemannian one. Many of the desirable properties for Euclidean kernel estimates carry over to the Riemannian setting. The issue of edge correction is also discussed and two criteria for bandwidth selection are proposed. These two selection criteria are explored through a simulation study. Finally, an important area of research in spatial statistics is exploring the interaction between different processes, for example how different species of plant spatially interact within some window. Under the framework of marked point processes we show that functional summary statistics for multivariate point patterns can be constructed on the sphere. This is extended to more general convex shapes through an appropriate mapping from the original shape to the sphere. A number of examples highlight that these summary statistics can capture independence, aggregation and repulsion between components of a multivariate process on both the sphere and more general surfaces.Open Acces

Investigating the ecology of native and non-native lianas in Central and Western New York

Woody vines, also called lianas, are increasing in abundance in temperate forests of the Northeastern United States. Both native and invasive taxa can alter community trajectories and affect ecosystem function, but invasive taxa such as oriental bittersweet (Celastrus orbiculatus) and Asian wisterias (Wisteria floribunda; Wisteria sinensis), are particularly problematic. Questions remain regarding whether these lianas are passengers or drivers of ecological change where they occur. To analyze the effects of invasive lianas in Central and Western New York, I constructed a two-part study. In the first portion of my research, I performed a selective liana-removal experiment within two local forests that contain infestations of C. orbiculatus and Wisteria floribunda. Over three growing seasons, I measured the effect of lianas on native tree-growth by comparing trees that had no history of liana-infestation to trees that were either still infested or had lianas cut. The impacts of liana treatment varied according to the initial trunk size and species of infested tree, with some evidence for negative impacts in a situationally-dependent manner. Overall, while mature tree growth was not impacted by lianas to the extent I predicted, future impacts of lianas on forest succession may reveal their more dramatic effects. For the second portion of my research, I compared sites with plant communities that supported C. orbiculatus to those supporting its native congener, C. scandens, to analyze for possible landscape and community patterns that could help to explain the occurrence and abundance of both species. While landscape patterns and community structure were similar between Celastrus sites, those with the invasive C. orbiculatus tended to have higher dominance by exotics and lower floristic quality. These results suggest that the encroachment of other exotics with C. orbiculatus into sites with C. scandens may be a symptom of underlying habitat disturbance. By quantifying conditions that may encourage the spread of invasive lianas and their impacts once present in plant communities, I highlight the challenge of regional conservation in a rapidly changing world

Precision Electro-Weak and Hadronic Luminosity Calculations

We have used YFS Monte Carlo techniques to obtain per-mil level accuracy for the Bhabha scattering cross section used in the luminosity monitor in electro-weak scattering experiments. We will describe techniques for extending these methods for use in the W production luminosity cross section for hadron colliders.Comment: 8 pages (LaTex) with 5 figures (EPS). Presented by S.A. Yost at the Third International Symposium on Quantum Theory and Symmetries, Cincinnati, Sept. 10 - 14, 200

Understanding the effects of violent video games on violent crime

Psychological studies invariably find a positive relationship between violent video game play and aggression. However, these studies cannot account for either aggressive effects of alternative activities video game playing substitutes for or the possible selection of relatively violent people into playing violent video games. That is, they lack external validity. We investigate the relationship between the prevalence of violent video games and violent crimes. Our results are consistent with two opposing effects. First, they support the behavioral effects as in the psychological studies. Second, they suggest a larger voluntary incapacitation effect in which playing either violent or non-violent games decrease crimes. Overall, violent video games lead to decreases in violent crime. --Video Games,Violence,Crime