Physical Sciences and Mathematics Commons^™

Selective Multiple Imputation Of Keys For Statistical Disclosure Control In Microdata, Rod Little, Fang Liu

The University of Michigan Department of Biostatistics Working Paper Series

The fundamental tension in statistical disclosure control (SDC) of microdata is the trade-off between the protection of individual respondents and the release of enough information for statistical inferences. We consider microdata that include key variables that contain identifying information and target variables that include sensitive information. Releasing the original data may expose some individuals in the sample to high risk of disclosure; deleting key variables is a common approach, but this loses information for some statistical analysis. This paper proposes selective multiple imputation of key variables (SMIKe) as an alternative SDC technique between those two extremes, and applies SMIKe to …

Khovanov Homology And Conway Mutation, Stephan Wehrli

Mathematics - All Scholarship

We present an easy example of mutant links with different Khovanov homology. The existence of such an example is important because it shows that Khovanov homology cannot be defined with a skein rule similar to the skein relation for the Jones polynomial.

Determination Of 4,4'-Dinitrocarbanilide (Dnc), A Component Of Nicarbazin, In Canada Goose (Branta Canadensis) Eggshells Using High-Performance Liquid Chromatography, Randal S. Stahl, Kurt C. Vercauteren, Teresa L. Buettgenbach, John J. Johnston

United States Department of Agriculture Wildlife Services: Staff Publications

A method was developed using high-performance liquid chromatography to assay 4,4'-dinitrocarbanilide (DNC), the active ingredient in Nicarbazin, in eggshells collected from Canada geese fed a formulated feed fortified with Nicarbazin at doses of 0, 125, 250, and 500 μg/g. The method was developed using chicken eggshells fortified with DNC. The method was used to quantify DNC in both the shell-associated membranes and the calcified shell extracellular matrix. These values were compared to those obtained for a composite sample consisting of both the membranes and the calcified shell extracellular matrix. The validated method was used to quantify DNC in eggshells from …

Estimating Disease Prevalence In Two-Phase Studies, Todd A. Alonzo, Margaret S. Pepe

UW Biostatistics Working Paper Series

Disease prevalence is ideally estimated using a “gold standard” to ascertain true disease status on all subjects in a population of interest. In practice, however, the gold standard may be too costly or invasive to be applied to all subjects, in which case a two-phase design is often employed. Phase 1 data consisting of inexpensive and non-invasive screening tests on all study subjects are used to determine the subjects that receive the gold standard in the second phase. Naïve estimates of prevalence in two-phase studies can be biased (verification bias). Imputation and re-weighting estimators are often used to avoid this …

A General Model For Predicting Brown Tree Snake Capture Rates, Richard M. Engeman, N. Paige Groninger, Daniel S. Vice

United States Department of Agriculture Wildlife Services: Staff Publications

The inadvertent introduction of the brown tree snake (Boiga irregularis) to Guam has resulted in the extirpation of most of the island’s native terrestrial vertebrates, has presented a health hazard to small children, and also has produced economic problems. Trapping around ports and other cargo staging areas is central to a program designed to deter dispersal of the species. Sequential trapping of smaller plots is also being used to clear larger areas of snakes in preparation for endangered species reintroductions. Traps and trapping personnel are limited resources, which places a premium on the ability to plan the deployment …

An Analysis Of The Melt Casting Of Metallic Fuel Pins, Xiaolong Wu, Randy Clarksean, Yitung Chen Yitung.Chen@Unlv.Edu, Darrell Pepper, Mitchell K. Meyer

Fuels Campaign (TRP)

• Background

– Casting Volatile Actinides

– Need to Contain Americium

– Overview of Project

• Fuel Rod Model

– Physical System

– Governing Equations

• Preliminary Modeling Results

– Mold Materials

– Injection Casting Velocity

Magmatic Subsidence Of The East Pacific Rise (Epr) At 18˚14'S Revealed Through Fault Restoration Of Ridge Crest Bathymetry, S M. Carbotte, William B F Ryan, Wen Jin, Marie-Helene Cormier, Eric Bergmanis, John Sinton, Scott M. White

Faculty Publications

The fault restoration technique of De Chabalier and Avouac [1994] is applied to an ultra-highresolution bathymetry data set from the East Pacific Rise (EPR) at 18140S. Fault offsets are calculated and subtracted from the original seafloor bathymetry to examine the morphology of the unfaulted seafloor surface within an area encompassing the ridge axis 400 [1] 1600 m in dimension. The restored topography reveals a gently sloping seafloor 200 m wide, which slopes 5 inward toward the spreading axis. We attribute this inward sloping seafloor to subsidence within the axial trough due to subsurface magmatic deflation. The vertical deformation field extracted …

Calibration Of Ysz Sensors For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic, Xiaolong Wu, Ramkumar Sivaraman, Ning Li, Wei Hang, T. W. Darling, Yingtao Jiang, Woosoon Yim, Bingmei Fu

Transmutation Sciences Materials (TRP)

Although liquid lead-bismuth eutectic (LBE) is a good candidate for coolant in the subcritical transmutation blanket, it is known to be corrosive to stainless steel, the material of the carrying tubes and containers. Such longterm corrosion problem can be prevented by producing and maintaining a protective oxide layer on the exposed surface of stainless steel. For this purpose, it is required to accurately control the concentration of oxygen dissolved in LBE. Currently, YSZ (Yttria Stabilized Zirconia) oxygen sensors, based on an existing automotive oxygen sensor, with molten bismuth saturated with oxygen as the reference, have been selected for oxygen-concentration measurement. …

Development Of A Systems Engineering Model Of The Chemical Separations Process, Lijian Sun, Haritha Royyuru, Yitung Chen, Randy Clarksean, Darrell Pepper, George Vandegrift, James Laidler

Separations Campaign (TRP)

Project Overview:

• Two Components

– Refine AMUSE Code

– Develop Systems Engineering Model

• Research Objectives

– Develop a framework and environment for a systems engineering analysis of the chemical separations system for the AAA program.

– Establish a baseline systems engineering model from which modifications and improvements can be made.

– Refine the existing AMUSE program that gives a detailed examination of the UREX process, a critical component of the overall separation scheme.

The Design And Performance Of Special Purpose Middleware: A Sensor Networks Case Study, Venkita Subramonian, Guoliang Xing, Christopher Gill, Ron Cytron

All Computer Science and Engineering Research

General purpose middleware has been shown to be effective in meeting diverse functional requirements for a wide range of distributed systems. Advanced middleware projects have also supported a single quality-of-service dimension such as real-time, fault tolerance, or small memory footprint. However, there is limited experience supporting multiple quality-of-service dimensions in mid-dleware to meet the needs of special purpose applications. Even though general purpose middleware can cover an entire spectrum of applications by supporting the union of all features required by each application, this approach breaks down for distributed real-time and embedded systems. In particular, features from one dimension such as …

Lidar Investigations Of The Middle Atmosphere Or What Is The Middle Atmosphere, What Is The Green Beam, And What Is The Red Beam?, Vincent B. Wickwar

Presentations

No abstract provided.

Spinors, Inflation, And Non-Singular Cyclic Cosmologies, Christian Armendariz-Picon, Patrick B. Greene

Physics - All Scholarship

We consider toy cosmological models in which a classical, homogeneous, spinor field provides a dominant or sub-dominant contribution to the energy-momentum tensor of a flat Friedmann-Robertson-Walker universe. We find that, if such a field were to exist, appropriate choices of the spinor self-interaction would generate a rich variety of behaviors, quite different from their widely studied scalar field counterparts. We first discuss solutions that incorporate a stage of cosmic inflation and estimate the primordial spectrum of density perturbations seeded during such a stage. Inflation driven by a spinor field turns out to be unappealing as it leads to a blue …

Analysis Of The Shadow-Sausage Effect Caustic, James A. Lock, Charles L. Adler, Diana Ekelman, Jonathan Mulholland, Brian Keating

Physics Faculty Publications

We analyze the optical caustic produced by light refracted at the curved meniscus surrounding a cylindrical rod standing partially out of a liquid-filled container. When the rod is tilted from the vertical or when light is diagonally incident, the caustic is a four-cusped astroid with two of its cusps obscured by the rod's shadow. If a portion of the flat end of the rod is raised above the water level, the caustic evolves into a pattern of five interlocking cusps. The five cusps result from symmetry breaking of a three-cusped surface perturbation caustic. (C) 2003 Optical Society of America.

Simulating Coronas In Color, Stanley D. Gedzelman, James A. Lock

Physics Faculty Publications

Coronas are simulated in color by use of the Mie scattering theory of light by small droplets through clouds of finite optical thickness embedded in a Rayleigh scattering atmosphere. The primary factors that affect color, visibility, and number of rings of coronas are droplet size, width of the size distribution, and cloud optical thickness. The color sequence of coronas and iridescence varies when the droplet radius is smaller than similar to6-mum. As radius increases to approximately 3.5 mum, new color bands appear at the center of the corona and fade as they move outward. As the radius continues to increase …

A Ccwhc Technical Bulletin: Drug Residues In Wild Meat – Addressing A Public Health Concern, Marc Cattet

Canadian Cooperative Wildlife Health Centre: Newsletters and Publications

Veterinary drugs play a valuable role in wildlife management and research. They are used widely for a variety of reasons, in particular, the capture and restraint of wild animals (Table 1). However, the availability and use of veterinary drugs is threatened if government regulations or the public trust are violated. Drug residues in wildlife are an important public health concern, especially for those who consume wild meat. Although the likelihood of consuming meat from a wild animal administered drug shortly before death is small, wildlife personnel (conservation officers, park wardens, biologists, veterinarians, etc.) are still confronted from time to time …

Light And Color In The Open Air: Introduction To The Feature Issue, Charles L. Adler, James A. Lock

Physics Faculty Publications

This special feature of Applied Optics reports the results of new experimental and theoretical research concerning a number of naked-eye optical phenomena, including ice-crystal halo displays, mirages, rainbows, glories, optical caustics, clear-sky phenomena, cloud coronas, cloud iridescence, and the extinction of skylight. (C) 2003 Optical Society of America.

Experimental Observation Of Total-Internal-Reflection Rainbows, Charles L. Adler, James A. Lock, Jonathon Mulholland, Brian Keating, Diana Ekelman

Physics Faculty Publications

A new class of rainbows is created when a droplet is illuminated from the inside by a point light source. The position of the rainbow depends on both the index of refraction of the droplet and the position of the light source, and the rainbow vanishes when the point source is too close to the center of the droplet. Here we experimentally measure the position of the transmission and one-internal-reflection total-internal-reflection rainbows, and the standard (primary) rainbow, as a function of light-source position. (C) 2003 Optical Society of America.

Prevalence And Economic Value Of Feral Swine Damage To Native Habitat In Three Florida State Parks, Richard M. Engeman, Henry T. Smith, Stephanie A. Shwiff, Bernice Constantin, John Woolard, Mark Nelson, Daniel Griffin

United States Department of Agriculture Wildlife Services: Staff Publications

Feral swine (Sus scrofa) adversely affect the environment in many of the places where they have been introduced. Such is the case in Florida, but quantification and economic evaluation of the damage can provide objective bases for developing strategies to protect habitats. Swine damage to native wet pine-flatwoods at three state parks in Florida was monitored from winter 2002 to winter 2003. Economic valuations of damage were based on the US dollar amounts that wetland regulators have allowed permit applicants to spend in attempts to replace lost resources. The parks had different swine management histories and the damage …

An Economic Assessment Of The Potential For Predator Management To Benefit Puerto Rican Parrots, Richard M. Engeman, Stephanie A. Shwiff, Felipe Cano, Bernice Constantin

United States Department of Agriculture Wildlife Services: Staff Publications

The Puerto Rican parrot is one of the ten most endangered birds in the world, with the only wild population comprised of 30-40 birds. Predation has been identified as one of the factors limiting Puerto Rican parrot productivity in the wild, and the loss of a very few birds can have a great impact on the species. Management of red-tailed hawks, and black rats, feral cats and Indian mongooses, as well as further management of pearly-eyed thrashers is potentially beneficial to the parrot population. Because funding for the recovery of this rare species is finite, an analytical examination of the …

Leiocephalus Carinatus Armouri (Northern Curlytailed Lizard) Opportunistic Predation, Henry T. Smith, Richard M. Engeman

United States Department of Agriculture Wildlife Services: Staff Publications

Distinctive circumstances can result in opportunistic predation on atypical prey (Woodin and Woodin 198 1 . Florida Field Nat. 9:64). Here, we document an opportunistic predation event by a great barracuda on a northern curly-tailed lizard, Leiocephalus carinatus armouri>/i>, in South Florida.