Camera systematics and three-point correlations in modern photometric galaxy surveys

The goal of modern cosmology, broadly speaking, is to understand the behavior of the Universe at large scales, including the evolution of dark matter and dark energy over cosmic time. In the context of the modern paradigm of a universe dominated by dark energy and cold dark matter (LCDM), the goal is to detect deviations from LCDM predictions (new physics), and in the absence of those, to infer the value of the LCDM parameters. Advances this endeavor will require both improved constraints on systematic errors in raw astronomical data as well as improved statistical methods for extracting cosmological information from galaxy catalogs. Toward these ends, the first half of this thesis discusses methods for improving our ability to make precise and accurate measurements of galaxies in the universe using astronomical CCD imaging cameras. The second half of this thesis discusses a novel application of a statistical probe of the cosmic web of dark matter, the galaxy three-point correlation function, to photometric galaxy surveys, that allows us to extract more information of cosmological interest from the observed galaxy distribution. Both lines of research discussed in this thesis will be useful in future analyses of data from upcoming optical galaxy surveys, including the Large Synoptic Survey Telescope

Spontaneous plastic deformation of irradiated metallic glasses

Using large-scale molecular dynamics simulations, we predict that knock-on damage in irradiated metallic glasses leads to spontaneous anisotropic deformation, i.e., shape change in the absence of externally applied loads. The root cause of this behavior is anisotropic plastic deformation around nonspherical thermal spikes. Thermal spikes are nanoscale regions whose temperature briefly rises to several thousand K, causing rapid localized melting and quenching. Thermal spike-induced plasticity (TSIP) does not depend on electronic excitations and is distinct from the ion hammer effect. Macroscale TSIP is predicted to occur under unidirectional heavy ion and neutron irradiation. The consequences of TSIP for potential applications of metallic glasses under irradiation will be discussed

How Often Does the Best Team Win? A Unified Approach to Understanding Randomness in North American Sport

Statistical applications in sports have long centered on how to best separate signal (e.g. team talent) from random noise. However, most of this work has concentrated on a single sport, and the development of meaningful cross-sport comparisons has been impeded by the difficulty of translating luck from one sport to another. In this manuscript, we develop Bayesian state-space models using betting market data that can be uniformly applied across sporting organizations to better understand the role of randomness in game outcomes. These models can be used to extract estimates of team strength, the between-season, within-season, and game-to-game variability of team strengths, as well each team’s home advantage. We implement our approach across a decade of play in each of the National Football League (NFL), National Hockey League (NHL), National Basketball Association (NBA), and Major League Baseball (MLB), finding that the NBA demonstrates both the largest dispersion in talent and the largest home advantage, while the NHL and MLB stand out for their relative randomness in game outcomes. We conclude by proposing new metrics for judging competitiveness across sports leagues, both within the regular season and using traditional postseason tournament formats. Although we focus on sports, we discuss a number of other situations in which our generalizable models might be usefully applied

ΔSCOPE: A New Method to Quantify 3D Biological Structures and Identify Differences in Zebrafish Forebrain Development

Research in the life sciences has traditionally relied on the analysis of clear morphological phenotypes, which are often revealed using increasingly powerful microscopy techniques analyzed as maximum intensity projections (MIPs). However, as biology turns towards the analysis of more subtle phenotypes, MIPs and qualitative approaches are failing to adequately describe these phenotypes. To address these limitations and quantitatively analyze the three-dimensional (3D) spatial relationships of biological structures, we developed the computational method and program called ∆SCOPE (Changes in Spatial Cylindrical Coordinate Orientation using PCA Examination). Our approach uses the fluorescent signal distribution within a 3D data set and reorients the fluorescent signal to a relative biological reference structure. This approach enables quantification and statistical analysis of spatial relationships and signal density in 3D multichannel signals that are positioned around a well-defined structure contained in a reference channel. We validated the application of ∆SCOPE by analyzing normal axon and glial cell guidance in the zebrafish forebrain and by quantify- ing the commissural phenotypes associated with abnormal Slit guidance cue expression in the forebrain. Despite commissural phenotypes which display disruptions to the reference structure, ∆SCOPE was able to detect subtle, previously uncharacterized changes in zebrafish forebrain midline crossing axons and glia. This method has been developed as a user-friendly, open source program. We propose that ∆SCOPE is an innovative approach to advancing the state of image quantification in the field of high resolution microscopy, and that the techniques presented here are of broad applications to the life science field

Indications for the applicability of element signature analysis for the determination of the geographic origin of dried beef and poultry meat

In order to determine the geographic origin of poultry and dried beef, concentrations of a total of 72 different elements (occasionally represented with several isotopes) were analyzed by inductively coupled plasma high resolution mass spectrometry (ICP-HRMS). Additionally, gross chemical composition (GCC) was analyzed. The 25 poultry breast filets samples originated from Switzerland, France, Germany, Hungary, Brazil, and Thailand, and the 23 dried beef samples, made from M. biceps femoris and M. semitendinosus, were produced in Switzerland, Austria, Australia, United States, and Canada out of raw meat originating either from these or from other countries. A total of 66 and 46 of the elements and isotopes followed were detected in beef and poultry, respectively. For statistical analyses, only the most abundant isotopes per element were used. For both poultry meat and dried beef, a differentiation of the origins was possible using those elements, which were significantly different across countries (As, Na, Rb, and Tl in poultry; B, Ca, Cd, Cu, Dy, Eu, Ga, Li, Ni, Pd, Rb, Sr, Te, Tl, Tm, V, Yb, and Zn in beef). No sufficient differentiation between origins was possible with GCC. Further studies have to confirm the suitability of this approach for meat authentication with more sample

KMg0.09Fe1.91(PO4)2

KMg0.09Fe1.91(PO4)2, potassium [iron(II)/magnesium] iron(III) bis(orthophosphate), is a solid solution derived from compounds with general formula KM IIFe(PO4)2 (M II = Fe, Cu), in which the Mg atoms substitute Fe atoms only in the octa­hedrally surrounded sites. The framework of the structure is built up from [FeO5] trigonal bipyramids and [MO6] (M = (Fe, Mg) octa­hedra sharing corners and edges and connected by two types of bridging PO4 tetra­hedra. The K+ cations are nine-coordinated and are situated in channels running along [101]

Understanding Non-traditional Hunters in New York: Initial Insights and Implications for Recruitment and Retention Research

Click on the PDF for an Executive Summary and the full report. Visit the HDRU website for a complete listing of HDRU publications at: http://hdru.dnr.cornell.edu