Physical Sciences and Mathematics Commons^™

Combining Multiple Models With Survival Data: The Phase Algorithm, Debashis Ghosh, Zheng Yuan

Debashis Ghosh

In many scientic studies, one common goal is to develop good prediction rules based on a set of available measurements. This paper proposes a model averaging methodology using proportional hazards regression models to construct new estimators of predicted survival probabilities. A screening step based on an adaptive searching algorithm is used to handle large numbers of covariates. The nite-sample properties of the proposed methodology is assessed using simulation studies. Application of the method to a cancer biomarker study is also given.

Author Guidelines For Reporting Scale Development And Validation Results In The Journal Of The Society For Social Work And Research, Peter Cabrera-Nguyen

Elián P. Cabrera-Nguyen

In this invited article, Cabrera-Nguyen provides guidelines for reporting scale development and validation results. Authors' attention to these guidelines will help ensure the research reported in JSSWR is rigorous and of high quality. This article provides guidance for those using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). In addition, the article provides helpful links to resources addressing structural equation modeling, multiple imputation for missing data, and a general resource for quantitative data analysis.

Optimal Dynamic Policies For Influenza Management, Michael Ludkovski, Jarad Niemi

Jarad Niemi

Management policies for influenza outbreaks balance the expected morbidity and mortality costs versus the cost of intervention policies. We present a methodology for dynamic determination of optimal policies in a completely observed stochastic compartmental model with parameter uncertainty. Our approach is simulation-based and searches the full set of sequential control strategies. For each time point, it generates a policy map describing the optimal intervention to implement as a function of outbreak state and Bayesian parameter posteriors. As a running example, we study a stochastic SIR model with isolation and vaccination as two possible interventions. Numerical simulations based on a classic …

Pollution And Public Health In A Shrinking World: Concentrated Animal Feeding Operations As A Paradigm For Emergent Needs In Environmental And Public Health Policy, Leland Stillman

Self-Designed Majors Honors Papers

Environmental factors play a major part in human health. Environmental pollutants are often as poisonous to humans as the environment. Presently, much time and energy is dedicated to keeping pollution apart from human society, with varying success. But as global population densities rise, current levels of pollution will become inviable due to public health concerns. An emergent example of this is in the concentration of livestock operations. Recent changes in the structure of U.S. hog farming have resulted in an industry-wide shift from small or medium production farms to high capacity, “concentrated animal feeding operations” (CAFO). These operations have become …

Modeling Super-Spreading Events For Sars, Thembinkosi P. Mkhatshwa

Theses, Dissertations and Capstones

One of the intriguing characteristics of the 2003 severe acute respiratory syndrome (SARS) epidemics was the occurrence of super spreading events (SSEs). Super-spreading events for a specific infectious disease occur when infected individuals infect more than the average number of secondary cases. The understanding of these SSEs is critical to under- standing the spread of SARS. In this thesis, we present a modification of the basic SIR (Susceptible - Infected - Removed) disease model, an SIPR (Susceptible - Regular Infected - Super-spreader - Removed) model, which captures the effect of the SSEs.

Santa Clara Magazine, Volume 52 Number 1, Summer 2010, Santa Clara University

Santa Clara Magazine

16 - COURAGE IN THE FACE A photoessay from Haiti by Michael Lattimore. A journey to document humanitarian work by doctors in the wake of the January quake.

20 - PILGRIMAGE By Martha Stortz. Walking the Camino to Santiago de Compostela, and learning a few things along the way: about big questions, saints, direction, and feet.

28 - THE HISTORIANS An interview by Ron Hansen M.A '95. Between them, historians George Giacomini '56 and Tim O'Keefe can claim nearly a century of educating Santa Clara students. This year, both close the books on teaching in the classroom. But first they …

Scholars Day Program Of Events 2010, Carl Goodson Honors Program

Scholars Day

No abstract provided.

A Database Server For Next-Generation Scientific Data Management, Mohamed Eltabakh, Walid G. Aref, Ahmed Elmagarmid

Cyber Center Publications

The growth of scientific information and the increasing automation of data collection have made databases integral to many scientific disciplines including life sciences, physics, meteorology, earth and atmospheric sciences, and chemistry. These sciences pose new data management challenges to current database system technologies. This dissertation addresses the following three challenges: (1) Annotation Management: Annotations and provenance information are important metadata that go hand-in-hand with scientific data. Annotating scientific data represents a vital mechanism for scientists to share knowledge and build an interactive and collaborative environment. A major challenge is: How to manage large volumes of annotations, especially at various granularities, …

Methods Of Competing Risks Analysis Of End-Stage Renal Disease And Mortality Among People With Diabetes, Hyun J. Lim, Xu Zhang, Roland Dyck, Nathaniel Osgood

Mathematics and Statistics Faculty Publications

Background: When a patient experiences an event other than the one of interest in the study, usually the probability of experiencing the event of interest is altered. By contrast, disease-free survival time analysis by standard methods, such as the Kaplan-Meier method and the standard Cox model, does not distinguish different causes in the presence of competing risks. Alternative approaches use the cumulative incidence estimator by the Cox models on cause-specific and on subdistribution hazards models. We applied cause-specific and subdistribution hazards models to a diabetes dataset with two competing risks (end-stage renal disease (ESRD) or death without ESRD) to measure …

A Philology Of Liberation: Dr. Martin Luther King, Jr. As A Reader Of The Classics, Thomas Strunk Ph.D.

Verbum Incarnatum: An Academic Journal of Social Justice

This paper explores the intellectual relationship between Dr. Martin Luther King, Jr. and the classics, particularly the works of Plato, Sophocles, and Aeschylus. Recognizing Dr. King as a reader of the classics is significant for two reasons: the classics played a formative role in Dr. King’s development into a political activist and an intellectual of the first order; moreover, Dr. King shows us the way to read the classics. Dr. King did not read the classics in a pedantic or even academic manner, but for the purpose of liberation. Dr. King’s legacy, thus, is not merely his political accomplishments but …

To Live And Die In Ca, Jane Frances Curnutt

Theses Digitization Project

This thesis investigates the nature of elementary cellular automata to better understand their relationship of the models they support to the biological organisms that create the mats and soil crusts found in extreme environments here on earth. Cellular automata have been used to study growth and patterns in forests, arid desert environments, predator-prey problems, and sea shells. It has also been used to study areas of diverse epidemiology and linguistics. Cellular automata have been used as the core of computer games as well. This investigation has led to develop a graphical grammar for simple cellular automata, using L-systems, a grammar …

Identifying Influential Observations Through The Intraclass Correlation Coefficient, Angel De Jesus Davalos

Open Access Theses & Dissertations

In this thesis, we analyze the performance of adapting the DFBETA statistic for identifying influential observations on the intraclass correlation coefficient under the assumptions of the one-way random effects model. Additionally, we introduce an approach for transforming negative intraclass correlation coefficient estimation values using the method of moments estimator. We apply this method on a data set of repeated blood pressure measurements, after which we will investigate implications of identifying influential observations.

A Deadline-Driven Epidemic Data Collection Protocol Suitable For Tracking Interpersonnel Rendezvous, Avranil Tah

Open Access Theses & Dissertations

This thesis describes a peer-to-peer wireless data collection algorithm that uses epidemic communication to propagate time-sensitive sequentially sampled data records from sensors toward infrastructure connected upload stations via mobile data mules. These records are labeled with sequence numbers and delivery deadlines, and are transmitted in sequential order. Delivery deadlines enable transmission prioritization and trigger alarms warning of violations.

The sequential ordering of records simplifies the protocols transmission-control and garbage collection mechanisms: only two monotonically increasing scalar sequence indices associated with a particular sensor must be exchanged between peers prior to selecting which records need to be communicated. One of these …

Spatio-Temporal Access Methods: Part 2 (2003 - 2010), Long-Van Nguyen-Dinh, Walid G. Aref, Mohamed Mokbel

Cyber Center Publications

In spatio-temporal applications, moving objects detect their locations via location-aware devices and update their locations continuously to the server. With the ubiquity and massive numbers of moving objects, many spatio-temporal access methods are developed to process user queries efficiently. Spatio- temporal access methods are classified into four categories: (1) Indexing the past data, (2) Indexing the current data, (3) Indexing the future data, and (4) Indexing data at all points of time. This short survey is Part 2 of our previous work [28]. In Part 2, we give an overview and classification of spatio-temporal access methods that are published between …

Privometer: Privacy Protection In Social Networks, Nilothpal Talukder, Mourad Ouzzani, Ahmed Elmagarmid, Hazem Elmeleegy

Cyber Center Publications

The increasing popularity of social networks, such as Facebook and Orkut, has raised several privacy concerns. Traditional ways of safeguarding privacy of personal information by hiding sensitive attributes are no longer adequate. Research shows that probabilistic classification techniques can effectively infer such private information. The disclosed sensitive information of friends, group affiliations and even participation in activities, such as tagging and commenting, are considered background knowledge in this process. In this paper, we present a privacy protection tool, called Privometer, that measures the amount of sensitive information leakage in a user profile and suggests selfsanitization actions to regulate the amount …

Evaluating And Regulating Lead In Artificial Turf, Gregory Van Ulirsch, Kevin Gleason, Shawn Gerstenberger, Deaphne B. Moffett, Glenn Pulliam, Tariq Ahmed, Jerald Fagliano

Environmental & Occupational Health Faculty Publications

Background: In 2007, a synthetic turf recreational field in Newark, New Jersey, was closed because lead was found in synthetic turf fibers and in surface dust at concentrations exceeding hazard criteria. Consequently, public health professionals across the country began testing synthetic turf to determine whether it represented a lead hazard. Currently, no standardized methods exist to test for lead in synthetic turf or to assess lead hazards.

Objectives: Our objectives were to increase awareness of potential lead exposure from synthetic turf by presenting data showing elevated lead in fibers and turf-derived dust; identify risk assessment uncertainties; recommend that federal and/or …

Inadequate Health Numeracy Affects Cancer Screening Practices In Vulnerable Populations, Sherrine Eid Mph, Dorothy Faulkner Phd

Administration & Leadership

No abstract provided.

Fire Effects On Demography Of The Invasive Shrub Brazilian Pepper (Schinus Terebinthifolius) In Florida Pine Savannas, Jens T. Stevens, Brian Beckage

College of Agriculture and Life Sciences Faculty Publications

Fire is a common disturbance in savanna ecosystems that may either facilitate or impede non-native plant invasions. Although fire can create recruitment opportunities for non-native plants, it can also prevent their invasion if it exerts strong negative effects on their demographic processes. Some savannas may, therefore, be able to resist invasion provided the natural, frequent-fire regime remains intact. We examined the effects of fire on the demography of the invasive shrub Brazilian pepper, Schinus terebinthifolius Raddi., which is invading fire-prone slash pine savannas of southern Florida. We studied survivorship, growth, and reproduction of low-density populations of Brazilian pepper in a …

Associative Learning In Larval Dosophila Melanogaster: The Role Of Heredity In Learning Speed And Persistence Of Leaning Into Adulthood, Jasmin Hicklen, Domonique Jones, Michelle Vieyra

Journal of the South Carolina Academy of Science

No abstract provided.

A Model For Understanding Epilepsy In Peromyscus, Kevin Ryan, Gabor Szalai

Journal of the South Carolina Academy of Science

No abstract provided.

A Correlational Study Of Telework Frequency, Information Communication Technology, And Job Satisfaction Of Home-Based Teleworkers, Shana P. Webster-Trotman

Walden Dissertations and Doctoral Studies

In 2008, 33.7 million Americans teleworked from home. The Telework Enhancement Act (S. 707) and the Telework Improvements Act (H.R. 1722) of 2009 were designed to increase the number of teleworkers. The research problem addressed was the lack of understanding of factors that influence home-based teleworkers' job satisfaction. Job dissatisfaction has been found to have a significant impact on voluntary turnover. The purpose of the study was to assess the relationship among telework frequency, information communication technology (ICT), and job satisfaction. The research questions were designed to answer whether correlational relationships exist among telework frequency, ICT, and job satisfaction and …

The Use Of Human Patient Simulators To Enhance The Clinical Decision Making Of Nursing Students, Sharon Kay Powell-Laney

Walden Dissertations and Doctoral Studies

One of the newest teaching modalities in nursing education is the use of human patient simulators (HPS). An HPS simulation scenario creates a software program vignette in which students interact with a manikin to practice caring for critical patients in a risk-free environment. Although used extensively in schools of nursing, there is little research that examines if these expensive simulators improve the clinical decision-making ability of nursing students. The purpose of this experimental differentiated treatment study was to assess if HPS technology leads to increased clinical decision-making ability and clinical performance more than the teaching modality of a paper and …

The Journal Of Undergraduate Research: Volume 08

The Journal of Undergraduate Research

This is the complete issue of the South Dakota State University Journal of Undergraduate Research, Volume 8.

Vowel Recognition From Continuous Articulatory Movements For Speaker-Dependent Applications, Jun Wang, Jordan R. Green, Ashok Samal, Tom D. Carrell

Department of Special Education and Communication Disorders: Faculty Publications

A novel approach was developed to recognize vowels from continuous tongue and lip movements. Vowels were classified based on movement patterns (rather than on derived articulatory features, e.g., lip opening) using a machine learning approach. Recognition accuracy on a single-speaker dataset was 94.02% with a very short latency. Recognition accuracy was better for high vowels than for low vowels. This finding parallels previous empirical findings on tongue movements during vowels. The recognition algorithm was then used to drive an articulation-to-acoustics synthesizer. The synthesizer recognizes vowels from continuous input stream of tongue and lip movements and plays the corresponding sound samples …

Application Of X-Ray Diffraction To Material Analysis And Medical Imaging, Wei Zhou

Legacy Theses & Dissertations (2009 - 2024)

Powder diffraction is commonly used to determine the structures of both inorganic and organic materials. The angle and intensity of the diffraction (also called coherent scatter) peak depends on the nanostructure of the material. When no x-ray optic is used, the peak width broadens, and hence the resolution worsens, as the sample area is increased. However, a small sample area gives low diffracted signal intensity, particularly for thin films and for organic materials, which have low diffraction cross sections. X-ray optics can be used in x-ray powder diffraction to increase the diffraction intensity, thus decreasing exposure times. For a small …

Heat Stress Evaluation Of Protective Clothing Ensembles, Amanda Lee Pease

USF Tampa Graduate Theses and Dissertations

Clothing directly affects the level of heat stress exposure. Useful measures to express the thermal characteristics are WBGT (wet bulb globe temperature) clothing adjustment factor (CAF) or apparent total evaporative resistance (R_e,T,_a). The CAF is assigned through laboratory wear trials following a heat stress protocol in which the air temperature and humidity are progressively increased until the participant clearly loses the ability to maintain thermal equilibrium. The critical condition is the point of thermal transition and from these conditions both the CAF and Re,T,a are computed. The first objective of this study is to compare the …

Climate Change And Sea Level Rise Initiative (Ccslri), Larry P. Atkinson

CCSLRI Brochures

Brochure of the Old Dominion University Climate Change and Sea Level Rise Initiative (CCSLRI)

Promiscuous Mating In Feral Pigs (Sus Scrofa) From Texas, Usa, Johanna Delgado-Acevedo, Angeline Zamorano, Randy W. Deyoung, Tyler A. Campbell, David G. Hewitt, David B. Long

United States Department of Agriculture Wildlife Services: Staff Publications

Context. Feral pigs represent a significant threat to agriculture and ecosystems and are disease reservoirs for pathogens affecting humans, livestock and other wildlife. Information on the behavioural ecology of feral pigs might increase the efficiency and effectiveness of management strategies.

Aims. We assessed the frequency of promiscuous mating in relation to oestrous synchrony in feral pigs from southern Texas, USA, an agroecosystem with a widespread and well established population of feral pigs. An association between multiple paternity of single litters and synchrony of oestrous may indicate alternative mating strategies, such as mateguarding.

Methods. We collected gravid sows at …

Santa Clara Magazine, Volume 51 Number 4, Spring 2010, Santa Clara University

Santa Clara Magazine

14 - BENDING LIGHT By Steven Boyd Saum. They wanted to show that green living is not a compromise. So, for the international Solar Decathlon, the SCU-led Team California built a house of light and wonder. And it was dazzling enough to win No. 3 on the planet.

22 - CONNECT THE DOTS By Scott Brown '93. From border security to disaster preparedness, Secretary of Homeland Security Janet Napolitano '79 has one immense portfolio. She's also the point person on immigration. How to put those together?

28 - THIS PLACE WE CALL HOME By Kristina Chiapella '09 '09. Generations ago, …

On The Eigenstructures Of Functional K-Potent Matrices And Their Integral Forms, Yan Wu, Daniel F. Linder

Biostatistics Faculty Publications

In this paper, a functional k-potent matrix satisfies the equation, where k and r are positive integers, and are real numbers. This class of matrices includes idempotent, Nilpotent, and involutary matrices, and more. It turns out that the matrices in this group are best distinguished by their associated eigen-structures. The spectral properties of the matrices are exploited to construct integral k-potent matrices, which have special roles in digital image encryption.