Medicine and Health Sciences Commons^™

Weighted Quantile Sum Regression For Analyzing Correlated Predictors Acting Through A Mediation Pathway On A Biological Outcome, Bhanu M. Evani

Theses and Dissertations

Abstract

Weighted Quantile Sum Regression for Analyzing Correlated Predictors Acting Through a Mediation Pathway on a Biological Outcome

By

Bhanu M. Evani, Ph.D.

A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University.

Virginia Commonwealth University, 2017.

Major Director: Robert A. Perera, Asst. Professor, Department of Biostatistics

This work examines mediated effects of a set of correlated predictors using the recently developed Weighted Quantile Sum (WQS) regression method. Traditionally, mediation analysis has been conducted using the multiple regression method, first proposed by Baron and Kenny (1986), which has since …

Weight Perception And Weight Loss Behaviors: A Comparison Between Adolescents With And Without Autism Spectrum Disorder, Elanor J. Anderson

Cal Poly Humboldt theses and projects

OBJECTIVE: The primary purpose of this study is to investigate the accuracy of weight status perception among adolescents with and without Autism Spectrum Disorder. A secondary purpose is to compare weight loss behaviors between children with and without ASD.

METHODS: This study measured weight-perception and weight loss behaviors among Irish-thirteen-year olds with ASD (n=47) and typically developing (TD) children (n=47) (72% male). Participants completed questionnaires assessing perception of weight and weight loss behaviors. . Based on BMI, calculated from height and weight measurements, participants were classified as non-overweight, overweight and obese. Several Chi-square tests were used to examine (1) differences …

Towards A Continuous Assessment Of Cognitive Workload For Smartphone Multitasking Users, Angel Jimenez-Molina, Hernan Lira

H-Workload 2017: Models and Applications (Works in Progress)

The intermeshing of Smartphone interactions and daily activities depletes the availability of cognitive resources. This excessive demand may lead to several undesirable cognitive states, which can be avoided by continuously assessing the user cognitive workload. Recently, many attempts have emerged to assess this workload by using psycho physiological signals. This paper provides evidence that it is possible to train models that accurately identify in short time windows such cognitive workload by processing heart rate and blood oxygen saturation signals. This assessment could be applied in Smartphone notification delivery, interface adaptations or cognitive capabilities evaluation.

Human Performance Modelling In Manufacturing: Mental Workload And Task Complexity, Maria Chiara Leva, Lorenzo Comberti, Micaela Demichela, Rebecca Duane

H-Workload 2017: Models and Applications (Works in Progress)

No abstract provided.

Distress And Worry As Mediators In The Relationship Between Psychosocial Risks And Upper Body Musculosketal Complaints In Highly Automated Manufacturing, Fiona Wixted, Leonard O'Sullivan

H-Workload 2017: Models and Applications (Works in Progress)

As a result of an upward trend in automation, the requirement for supervisory monitoring and consequently, cognitive demand has increased in automated manufacturing. The incidence of musculoskeletal disorders has also increased in the manufacturing sector. A model was developed based on survey data to test if distress and worry mediate the relationship between psychosocial factors (job control, cognitive demand, social isolation and skill discretion), stress states and upper body musculoskeletal complaints in highly automated manufacturing companies (n=235). Cognitive demand was shown to be related to higher distress in employees. The data raise the question about the link between job control …

Moving Between Automated And Manual Driving: Mental Workload And Performance Implications, Totsapon Butmee, Terry C. Lansdown

H-Workload 2017: Models and Applications (Works in Progress)

Automated driving has been predicted to take-over from manual vehicle control in the near future. The driver’s role may then change from active operator to passive observer. Such technology offers the tantalising promise of improving driving safety. However, many studies have presented findings suggesting potentially adverse effects from automated driving systems, e.g., reduced situation awareness. Mental workload is also a key issue of concern for researchers in this area. Excessive mental workload has repeatedly been shown to be associated with degraded driving performance. Previously, most traffic psychology studies on mental workload have focused the manual driving task. However, a shift …

Managing Operator Mental Workload With Standards Based Decision Support, Maurice Wilkins

H-Workload 2017: Models and Applications (Works in Progress)

H-Workload 2017: The first international symposium on human mental workload, Dublin Institute of Technology, Dublin, Ireland, June 28-30.

Facing Human Workload: The Resilient Ego: A Psychoanalytic Point Of View, Glauco Maria Genga, Maria Gabriella Pediconii

H-Workload 2017: Models and Applications (Works in Progress)

The paper aims to show new connections among Human Factors, Human Workload and Resilience. We intend: 1) to highlight the role of subject in facing the human workload, inflected as demanding tasks and emergency situations; 2) to show how psychoanalysis can provide novel insights, not only into human errors, but also into human resilience. They have a common denominator, at least in part: the role of subjective contributions even in demanding situations. Human workload includes a work for satisfaction. We recall also the case study of US Airways Flight 1549 water landing (the so called “Miracle on the Hudson”), which …

Petrochemical Plant Console Operator Workload:The Issues, David A. Strobhar

H-Workload 2017: Models and Applications (Works in Progress)

The console operators of certain petrochemical processes must maintain high levels of performance during process upsets or endanger personnel safety and the environment. Mismanagement of an upset can result in explosions, fires, and the release of hazardous chemicals to the environment. The change in workload from steady state to upset operation is significant, with alarms and control changes that are of an order of magnitude. This paper describes the state of console activity in process plants, particularly the increase with key upsets. Quantitative data on the nature of the console operator’s position, its workload during normal operation, and the requirements …

Marginal Structural Cox Model For Survival Data With Treatment-Confounder Feedback, Yanan Zhang

Theses and Dissertations

In an observational longitudinal study, there can be time-varying exposure/treatment and time-varying confounders. When the confounders affect the exposure and prior exposure also has an impact on levels of confounders, there is treatment confounder feedback. To admit estimation of unbiased causal effects, these conditions need to be hold, exchangeability, positivity, consistency. The traditional method of conditioning on potential confounders does not meet these 3 conditions. Therefore, parameter estimates from traditional Cox model are biased casual effect estimates when the treatment confounder feedback exists. The marginal structural Cox model can be used to address this issue. By calculating and including inverse …

A Rational Design Of A Selective Inhibitor For Kv1.1 Channels Prevalent In Demyelinated Nerves That Improves Their Impaired Axonal Conduction, Ahmed Al-Sabi, Declan Daly, Patrick Hoefer, Gemma K. Kinsella, Charles Metais, Mark Pickering, Caroline Herron, Seshu Kumar Kaza, Kieran Nolan, J. Oliver Dolly

Articles

K+ channels containing Kv1.1 α subunits, which become prevalent at internodes in demyelinated axons, may underlie their dysfunctional conduction akin to muscle weakness in multiple sclerosis. Small inhibitors were sought with selectivity for the culpable hyper-polarizing K+ currents. Modeling of interactions with the extracellular pore in a Kv1.1-deduced structure identified diaryldi(2-pyrrolyl)methane as a suitable scaffold with optimized alkyl ammonium side chains. The resultant synthesized candidate [2,2′-((5,5′(di-p-topyldiaryldi(2-pyrrolyl)methane)bis(2,2′carbonyl)bis(azanediyl)) diethaneamine·2HCl] (8) selectively blocked Kv1.1 channels (IC50 ≈ 15 μM) recombinantly expressed in mammalian cells, induced a positive shift in the voltage dependency of K+ current activation, and slowed its kinetics. It …

Feasibility Of Laser-Induced Breakdown Spectroscopy (Libs) As An At-Line Validation Tool For Calcium Determination In Infant Formula, Xavier Cama-Moncunill, Maria Markiewicz-Keszycka, Yash Dixit, Raquel Cama-Moncunill, Maria Piedad Casado-Gavalda, Patrick J. Cullen, Carl Sullivan

Articles

In this study, a 150 mJ laser-induced breakdown spectroscopy (LIBS) system was assessed to determine calcium content in infant formula (IF) samples. LIBS is a promising emission spectroscopic technique for elemental analysis, which offers advantages over conventional methods such as real-time analyses, little to no sample preparation and ease of use. The aim of this work was to evaluate the feasibility of LIBS as an at-line tool for IF manufacturing. To this end, IF mixtures with varying content of calcium were prepared over a range (approx. 1.5–7 mg/g of calcium) selected to be in conformity with the guidelines provided by …

Evaluation Of Chemical Immersion Treatments To Reduce Microbial Populations In Fresh Beef, Ahmed Kassem, Joseph Meade, James Gibbons, Kevina Mcgill, Ciara Walsh, James Lyng, Paul Whyte

Articles

The aim of the current study was to assess the ability of a number of chemicals (acetic Acid (AA), citric acid (CA) lactic acid (LA), sodium decanoate (SD) and trisodium phosphate (TSP)) to reduce microbial populations (total viable count, Campylobacter jejuni, Escherichia coli, Salmonella typhimurium and Listeria monocytogenes) on raw beef using an immersion system. The following concentrations of each chemical were used: 3 & 5% for AA, CA, LA, SD and 10 & 12% for TSP. Possible synergistic effects of using combinations of two chemicals sequentially (LA +CA and LA +AA) were also investigated. L*, a* and b* values …

Impact Of Atmospheric Pressure Nonequilibrium Plasma Discharge On Polymer Surface Metrology, Laurence Scally, James Lalor, Patrick J. Cullen, Vladimir Milosavljevic

Articles

Due to the attraction of plasma technologies as a clean and efficient means of surface modification, significant research has gone into the physical and chemical aspects of polymer functionalization. In this study, it was shown that the use of an atmospheric plasma jet can efficiently modify the surface of polyethylene terephthalate samples and change their hydrophobic properties to more hydrophilic characteristics. The dependence on the changes with respect to time, distance, and atomic oxygen (O I) intensity were considered as factors. It was found that with closer proximity to the plasma source (without causing thermal degradation) and with increasing levels …

An Iterative Bézier Method For Fitting Beta-Sheet Component Of A Cryo-Em Density Map, Michael Poteat, Jing He

Computer Science Faculty Publications

Cryo-electron microscopy (Cryo-EM) is a powerful technique to produce 3-dimensional density maps for large molecular complexes. Although many atomic structures have been solved from cryo-EM density maps, it is challenging to derive atomic structures when the resolution of density maps is not sufficiently high. Geometrical shape representation of secondary structural components in a medium-resolution density map enhances modeling of atomic structures. We compare two methods in producing surface representation of the β-sheet component of a density map. Given a 3-dimensional volume of β-sheet that is segmented from a density map, the performance of a polynomial fitting was compared with that …

Determination Of Spectral Markers Of Cytotoxicity And Genotoxicity Using In Vitro Raman Microspectroscopy: Cellular Responses To Polyamidoamine Dendrimer Exposure, Esen Efeoglu, Alan Casey, Hugh Byrne

Articles

Although consumer exposure to nanomaterials is ever increasing, with potential increased applications in areas such as drug and/or gene delivery, contrast agents and diagnosis, determination of cyto- and geno- toxic effect of nanomaterials on human health and the environment still remains challenging. Although many techniques have been established and adapted to determine the cytotoxicity and genotoxicity of nano-sized materials, these techniques remain limited by the number of assays required, total cost, use of labels and they struggle to explain the underlying interaction mechanisms. In this study, Raman microspectroscopy is employed as an in vitro label free high content screening technique …

Characterization Of Hiv Diversity, Phylodynamics And Drug Resistance In Washington, Dc., Marcos Pérez-Losada, Amanda D Castel, Brittany Lewis, Michael Kharfen, Charles P Cartwright, Bruce Huang, Taylor Maxwell, Alan E Greenberg, Keith A Crandall

Epidemiology Faculty Publications

No abstract provided.

Plasminogen Activator Inhibitor-1 Inhibitors And Methods Of Use Thereof To Modulate Lipid Metabolism, Daniel A. Lawrence, Cory Emal, Jacqueline Cale, Enming Joe Su, Mark Warnock, Shih-Hon Li, Jeanne Ann Cupp

Patents

The invention relates to plasminogen activator-I (PAI-1) inhibitor compounds and uses thereof in the treatment of any disease or condition associated with elevated PAI-1. The invention includes, but is not limited to, the use of such compounds to modulate lipid metabolism and treat conditions associated with elevated PAI-1, cholesterol, or lipid levels.

Phase I Dose-Escalation Trial Of Intravaginal Curcumin In Women For Cervical Dysplasia, Leda Gattoc, Paula M. Frew, Shontell N. Thomas, Kirk A. Easley, Laura Ward, H-H Sherry Chow, Chiemi A. Ura, Lisa Flowers

Environmental & Global Health Faculty Research

Background: This is a Phase I trial demonstrating safety and tolerability of intravaginal curcumin for future use in women with cervical neoplasia. Objective: The objective of this study was to assess the safety, tolerability, and pharmacokinetics of intravaginal curcumin in healthy women. Study design: We conducted a 3+3 dose-escalation Phase I trial in a group of women aged 18–45 years. Thirteen subjects were given one of four doses of curcumin powder (500 mg, 1,000 mg, 1,500 mg, and 2,000 mg) packed in gelatin capsules, which was administered intravaginally daily for 14 days. The primary end point for this study was …

The Chemistry Of The Flint Water Crisis, Ernest M. Oleksy

The Downtown Review: An Interdisciplinary Journal Written and Peer-Reviewed by Mandel Honors College Students at Cleveland State University

Politics and science do not always go hand-in-hand. Nowhere was this more clear than in the Flint Water Crisis. Negligence towards growing levels of lead poisoning in drinking water led to incredibly deleterious effects on Flint's citizens. The chemistry of equilibrium and the shortcomings of local leaders led to Flint's water becoming a crisis.

Myofilament Calcium Sensitivity: Consequences Of The Effective Concentration Of Troponin I, Jalal K. Siddiqui, Svetlana B. Tikunova, Shane D. Walton, Bin Liu, Meredith Meyer, Pieter P. De Tombe, Nathan Neilson, Peter M. Kekenes-Huskey, Hussam E. Salhi, Paul M.L. Janssen, Brandon J. Biesiadecki, Jonathan P. Davis

Chemistry Faculty Publications

Control of calcium binding to and dissociation from cardiac troponin C (TnC) is essential to healthy cardiac muscle contraction/relaxation. There are numerous aberrant post-translational modifications and mutations within a plethora of contractile, and even non-contractile, proteins that appear to imbalance this delicate relationship. The direction and extent of the resulting change in calcium sensitivity is thought to drive the heart toward one type of disease or another. There are a number of molecular mechanisms that may be responsible for the altered calcium binding properties of TnC, potentially the most significant being the ability of the regulatory domain of TnC to …

A Green Oasis: What Makes Community Gardens Worth Saving? While Researchers Amass Evidence Of Benefits, Advocates Develop New Strategy To Prove Their Value., Joel Wolfram

Capstones

Green Valley Community Garden in Brownsville, Brooklyn, is one of about a dozen gardens on land owned by the New York City Department of Housing Preservation and Development that are being uprooted by plans to build affordable housing. The gardeners are fighting back to prevent the garden’s destruction, saying that the food-producing green space is a source of healthy eating in a community with high rates of health problems, like diabetes and obesity. Researchers are attempting to tease out the public health benefits of community gardens as one metric of their value, but the science is still catching up with …

A Preliminary Examination Of Elevated Blood Lead Levels In A Rural Georgia County, R. Christopher Rustin, Yu Sun, Chris Calhoun, Christy Kuriatnyk

Environmental Health Sciences: Faculty Publications

Background: Rural areas are often viewed as lower risk for lead poisoning and toxic exposures seriously impacting development of the brain and central nervous system; this report examines the prevalence of elevated blood lead levels for children <6 years of age in rural Ben Hill County, GA.

Methods: Lead surveillance data from the Georgia Department of Public Health (DPH) were analyzed using SAS®v-9.3 to calculate the prevalence of elevated blood lead levels (≥5ug/dL) among those children in Ben Hill County who had been tested for lead; the results were compared to Georgia and national data.

Results: A preliminary analysis of 2010-2015 screening data for Ben Hill County indicates that 8.73% …

An Assessment Of Data Related To Inspections Of Risk Factors For Public Swimming Pools, Shanita Shack, Maurice Redmond, R. Christopher Rustin

Environmental Health Sciences: Faculty Publications

Background: The Georgia Department of Public Health (DPH) is mandated to ensure that public swimming pools are safe for those who use them. This mandate is carried out by the DPH and local environmental health professionals through regulations and inspections. In 2015, legislation was introduced proposing to reduce the authority of the DPH to inspect certain pool types (apartments, subdivision, condominiums) and thus reduce regulatory protections in place for swimmers. To ensure that the DPH had current information on the risks associated with pools, the EH team, with assistance from a graduate student, analyzed inspection data to evaluate risk factors …

Birthing Center Versus Hospitalized Birth, Nicolette Larsen

CrissCross

There are many risks and benefits of giving birth at a birthing center versus a hospital. Determining the location of birth is an important decision, as women in the world today have many options of where to have their child. Hospitals and birthing centers are two places where medical professionals provide prenatal, labor and delivery, and postpartum care for the mother and fetus during this memorable time. While hospital nurses and physicians provide advanced medical care, birthing centers focus on holistic care of the family unit emphasizing mental, spiritual, and physical health. Doctors often perform cesarean sections (C-sections) for non-medical …

Lilliput Effect Dynamics Across The Cretaceous-Paleogene Mass Extinction: Approaches, Prevalence, And Mechanisms, Matthew Brett Jarrett

USF Tampa Graduate Theses and Dissertations

An organism's body size entails both physiological and ecological costs. Furthermore, as a parameter in analyzing organisms, it represents a fundamental and essential morphometric character. Reductions in size following mass extinction is a commonly observed phenomenon in the fossil record. This study examines the evolutionary significance of this phenomenon termed the: 'Lilliput Effect' by proposing that it represents a rapid evolutionary response to altered selection pressures during a mass extinction. This primary hypothesis is evaluated against two additional hypotheses of size reduction: 1) stunted growth as a response to stressed ecosystems, and/or 2) mass extinctions are size selective.

These hypotheses …

An Examination Of The Neural Unreliability Thesis Of Autism, John Butler, Sophie Molholm, Gizely Andrade, John J. Foxe

Articles

An emerging neuropathological theory of Autism, referred to here as “the neural unreliability thesis,” proposes greater variability in moment-to-moment cortical representation of environmental events, such that the system shows general instability in its impulse response function. Leading evidence for this thesis derives from functional neuroimaging, a methodology ill-suited for detailed assessment of sensory transmission dynamics occurring at the millisecond scale. Electrophysiological assessments of this thesis, however, are sparse and unconvincing. We conducted detailed examination of visual and somatosensory evoked activity using high-density electrical mapping in individuals with autism (N = 20) and precisely matched neurotypical controls (N = 20), recording …

Discovery Of An Enzyme And Substrate Selective Inhibitor Of Adam10 Using An Exosite-Binding Glycosylated Substrate, Franck Madoux, Daniela Dreymuller, Jean-Phillipe Pettiloud, Radleigh Santos, Christoph Becker-Pauly, Andreas Ludwig, Gregg B. Fields, Thomas Bannister, Timothy P. Spicer, Mare Cudic, Louis D. Scampavia, Dmitriy Minond

Mathematics Faculty Articles

ADAM10 and ADAM17 have been shown to contribute to the acquired drug resistance of HER2-positive breast cancer in response to trastuzumab. The majority of ADAM10 and ADAM17 inhibitor development has been focused on the discovery of compounds that bind the active site zinc, however, in recent years, there has been a shift from active site to secondary substrate binding site (exosite) inhibitor discovery in order to identify non-zinc-binding molecules. In the present work a glycosylated, exosite-binding substrate of ADAM10 and ADAM17 was utilized to screen 370,276 compounds from the MLPCN collection. As a result of this uHTS effort, a selective, …

Very Rapid Onset Cannabis Dependence Risk In Relation To Co-Occurring Use Of Other Psychoactive Drugs, Olga A. Vsevolozhskaya, Fernando A. Wagner, James C. Anthony

Biostatistics Presentations

Background: Epidemiological estimates for lifetime cumulative incidence indicate that for every 9-11 who start using cannabis, one becomes a case of the cannabis dependence syndrome (CDS) – i.e., roughly 9%-11%. More recent estimates clarify that CDS risk might be much lower among ’cannabis only’ users, due in part to the fact that many ’cannabis only’ users try the drug a few times and never again. We turned to Hill functional analysis in order to study CDS probability soon after 1st cannabis use, estimated across strata defined by the number of recent days of cannabis use, with an acknowledgment that a …

Investigations Into The Effects Of Water Exchange And The Structure Of Lanthanide Chelates, Katherine Marie Payne

Dissertations and Theses

Lanthanide chelates are effective agents for improving contrast in MR images. Optimizing the relaxation of inner sphere water molecules is a common focus of research in this field. However, the efforts to design an optimal contrast agent have commonly over-looked the relationship of water position and water exchange kinetics. This work explores structural conformation, the impact of very fast water exchange kinetics on hydration, and differing tumbling rates for regioisomers of a number of lanthanide chelates. We have grown crystals of LnDOTMA and obtained structural data by X-ray diffraction that provide a picture of the chelate during water exchange and …