Digital Commons Network^™

Reproductive Numbers For Periodic Epidemic Systems, Christopher David Mitchell

Mathematics Dissertations - Archive

When using mathematics to study epidemics, often times the goal is to deter- mine when an infection can invade and persist within a population. This can be done in a variety of ways but the most common is to use threshold quantities called reproductive numbers. For models with only one infection, the basic reproductive number (BRN) is used to determine the stability of the disease-free equilibrium. For many years this was done solely for autonomous systems; however, many diseases exhibit seasonal behavior. If this seasonality is incorporated into models, it gives nonautonomous systems, which while more accurate in their description, …

A Two-Strain Tb Model With Multiple Latent Stages, Azizeh Jabbari, Carlos Castillo-Chavez, Fereshteh Nazari, Baojun Song, Hossein Kheiri

Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works

A two-strain tuberculosis (TB) transmission model incorporating antibiotic-generated TB resistant strains and long and variable waiting periods within the latently infected class is introduced. The mathematical analysis is carried out when the waiting periods are modeled via parametrically friendly gamma distributions, a reasonable alternative to the use of exponential distributed waiting periods or to integral equations involving "arbitrary" distributions. The model supports a globally-asymptotically stable disease-free equilibrium when the reproduction number is less than one and an endemic equilibriums, shown to be locally asymptotically stable, or l.a.s., whenever the basic reproduction number is greater than one. Conditions for the existence …

Antibacterial Drug Design And Discovery Via Vitamin B1 Biosynthetic Pathway, Abu Afzal Mohammad Shakar

Chemistry & Biochemistry Theses - Archive

Antibiotics play a vital role in fighting infectious disease caused by bacterial species. Antimicrobial resistance has been shown for every current antibiotic and poses a major health risk. To combat these growing threats to human health; new molecules must be investigated to treat bacterial infection. Chemical inhibition of the vitamin B1 biosynthetic pathway in the bacterial cell was hypothesized to inhibit the survival of bacteria. A series of synthetic molecules, which resemble metabolites of the vitamin B1 pathway, exhibit the inhibition of specific enzymes within this pathway and display initial activity against bacterial growth and survival. The beneficial activity of …

Mathematical Models Of Ebola Virus Disease And Vaccine Preventable Diseases, Yinqiang Zheng

Open Access Dissertations

This thesis focuses on applying mathematical models to studies on the transmission dynamics and control interventions of infectious diseases such as Ebola virus disease and vaccine preventable diseases.

Many models in studies of Ebola transmission are based on the model by Legrand et al. (2007). However, there are potential issues with the Legrand model. First, the model was originally formulated in a complex form, leading to confusion and hindering its uses in practice. To overcome the difficulty, the Legrand model is reformulated in a much simpler but equivalent form in this thesis. The reformulated model also provides an intuitive understanding …

Biomarkers For Radiation Pneumonitis Using Noninvasive Molecular Imaging, Meetha Medhora, Steven Haworth, Yu Liu, Jayashree Narayanan, Feng Gao, Ming Zhao, Said H. Audi, Elizabeth R. Jacobs, Brian L. Fish, Anne V. Clough

Mathematics, Statistics and Computer Science Faculty Research and Publications

Our goal is to develop minimally invasive biomarkers for predicting radiation-induced lung injury before symptoms develop. Currently, there are no biomarkers that can predict radiation pneumonitis. Radiation damage to the whole lung is a serious risk in nuclear accidents or in radiologic terrorism. Our previous studies have shown that a single dose of 15 Gy of x-rays to the thorax causes severe pneumonitis in rats by 6–8 wk. We have also developed a mitigator for radiation pneumonitis and fibrosis that can be started as late as 5 wk after radiation. Methods: We used 2 functional SPECT probes in vivo in …

Stream Microbial Communities As Potential Indicators Of River And Landscape Disturbance In North-Central Arkansas, Wilson Howard Johnson

Graduate Theses and Dissertations

In the past decade, 29 shale basins have been actively developed across 20 states for extraction of natural gas (NG) via horizontal drilling/hydraulic fracturing (=fracking). This includes ~5000 wells within the Fayetteville shale of north-central Arkansas. Development often impacts both river- and landscapes, and management requires catchment-level evaluations over time, with organismal presence/absence as indicators. For this study next-generation sequencing was used to identify/characterize microbial communities within biofilm of eight Arkansas River tributaries, so as to gauge potential catchment influences. Streams spanned a gradient of landscape features and hydrological flows, with four serving as ‘potentially impacted catchment zones’ (PICZ) and …

Extraction, Purification And Characterization Of An Antibiotic-Like Compound Produced By Rhodococcus Sp. Mtm3w5.2, Pushpavathi Reddyvari Manikindi

Electronic Theses and Dissertations

The bacterium Rhodococcus is a potential source for novel antimicrobial metabolites. Recently, the Rhodococcus strain MTM3W5.2 was isolated from a soil sample collected from Morristown, East Tennessee and was found to produce an inhibitor molecule that is active against similar Rhodococcus species. The aim of this research is to extract, purify, and characterize the active compound. The compound was obtained from both agar and broth cultures of strain MTM3W5.2 and purified by primary fractionation of crude extract on a Sephadex LH-20 column, followed by semi-preparative reversed phase column chromatography. Final purification was achieved using multiple rounds of an analytical C …

Spread Of Tylodelphys Mashonense (Digenea: Diplostomidae) By Grey Heron Ardea Cinerea And Great White Egret A. Alba In Lake Victoria, Tanzania, Fred D. Chibwana, Gamba Nkwengulila

Tanzania Journal of Science

Despite the fact that Tylodelphys mashonense, parasites of the cranial cavity of the catfish Clarias gariepinus, are ubiquitous in freshwater systems, little is known on their spread. As such, we examined a total of 152 piscivorous birds, belonging to 6 species; 43 great cormorant Phalacrocorax carbo, 33 grey heron Ardea cinerea, 26 hamerkop Scopus umbretta, 22 great white egret Ardea alba, 15 marabou stork Leptoptilos crumeniferus and 13 pied kingfisher Ceryle rudis foraging in the Lake Victoria. Out of the six bird species only A. cinerea and A. alba were found infected by T. mashonense with prevalence of 42.4% and …

Temporal And Spatial Distribution Of Cetacean Strandings Focusing On The Bottlenose Dolphin (Tursiops Truncatus) With A Synthesis Of Potential Causes, April D. Clark

HCNSO Student Capstones

A comprehensive review of the literature and a quantitative statistical analysis of that information are presented. A total of 6,015 cetaceans stranded at 36 locations from 24 peer reviewed articles published between 1999 and 2014 are documented, with the two most common stranding locations being the Canary Islands - accounting for 49 of the total cetacean stranding events - and Cape Cod - accounting for 31 of total cetacean stranding events. The documented cetacean stranding events included 805 for bottlenose dolphins (Tursiops truncatus) at a total of ten locations from 11 peer reviewed articles. When all single stranding …

Artificial Intelligence And Amikacin Exposures Predictive Of Outcomes In Multidrug-Resistant Tuberculosis Patients, Chawangwa Modongo, Jotam G. Pasipanodya, Shashikant Srivastava, Nicola Zetola, Scott Williams, Giorgio Sirugo, Tawanda Gumbo

Dartmouth Scholarship

Aminoglycosides such as amikacin continue to be part of the backbone of treatment of multidrug-resistant tuberculosis (MDR- TB). We measured amikacin concentrations in 28 MDR-TB patients in Botswana receiving amikacin therapy together with oral levofloxacin, ethionamide, cycloserine, and pyrazinamide and calculated areas under the concentration-time curves from 0 to 24 h (AUC0 –24). The patients were followed monthly for sputum culture conversion based on liquid cultures. The median duration of amikacin therapy was 184 (range, 28 to 866) days, at a median dose of 17.30 (range 11.11 to 19.23) mg/kg. Only 11 (39%) pa- tients had sputum culture conversion during …

Optimal Control Analysis Of Ebola Disease With Control Strategies Of Quarantine And Vaccination, Muhammad Dure Ahmad, Muhammad Usman, Adnan Khan, Mudassar Imran

Mathematics Faculty Publications

The 2014 Ebola epidemic is the largest in history, affecting multiple countries in West Africa. Some isolated cases were also observed in other regions of the world.

What Motivates High School Students To Take Precautions Against The Spread Of Influenza? A Data Science Approach To Latent Modeling Of Compliance With Preventative Practice, William L. Romine, Tanvi Banerjee, William R. Folk, Lloyd H. Barrow

Kno.e.sis Publications

– This study focuses on a central question: What key behavioral factors influence high school students’ compliance with preventative measures against the transmission of influenza? We use multilevel logistic regression to equate logit measures for eight precautions to students’ latent compliance levels on a common scale. Using linear regression, we explore the efficacy of knowledge of influenza, affective perceptions about influenza and its prevention, prior illness, and gender in predicting compliance. Hand washing and respiratory etiquette are the easiest precautions for students, and hand sanitizer use and keeping the hands away from the face are the most difficult. Perceptions of …

Circulation, Vol. 21, No. 3, Center For Coastal Physical Oceanography, Old Dominion University, Larry Atkinson

CCPO Circulation

Summer 2016 issue of CCPO Circulation featuring article "How Did I Get Here? The Answer: Sea-Level Rise" by Larry Atkinson.

Structural And Functional Studies Of Nicotinamide Adenine Dinucleotide And Streptolysin S Biosynthesis Proteins From Streptococcus Pyogenes, William T. Booth

Theses and Dissertations

Invasive infections caused by Streptococcus pyogenes, also known as Group A Strep (GAS), results in approximately 600,000 deaths annually. With evidence of antibiotic-resistant strains of this bacterium on the rise, there is a need for the identification of new drug targets to control these infections. In our approach we target the quinolinate-salvage pathway (QSP) and the streptolysin S (SLS) biosynthesis pathway. The QSP provides a secondary pathway for NAD+ biosynthesis within this organism; the SLS pathway leads to the formation of a quorum sensing molecule (SLS). We hypothesize that inhibition of the pathways will lead to GAS cell death or …

From Near And Far: Utilization Of In-Situ And Remotely Sensed Satellite Data From Nasa And Noaa, Jessica Rochelle Price Sutton

Theses and Dissertations

Satellite remote sensing observations have been used for numerous studies to better understand physical and biological properties over varying spatial and temporal scales. Depending on the satellite and sensor, the satellite-derived observations can provide high spatial and temporal resolution for many important physical and biological variables. While there are many limitations in utilizing satellite remote sensing products, there are also many advantages. This dissertation investigates three different applications for satellite remote sensing products to address climatological and ecological concerns. This dissertation is motivated by two overall research questions: (1) How can satellite remote sensing products be used to address important …

Inquiry Of Lipid Membranes Interacting With Functional Peptides And Polyphenol Drug Molecules, Chian Sing Ho

USF Tampa Graduate Theses and Dissertations

Cellular membranes are important targets for many membrane-active peptides and drug compounds. Here we are interested in deciphering how lipid membranes are perturbed by several membrane-active molecules, including the transmembrane domain of the influenza M2 protein (M2TM), aggregates formed by a synthetic polyglutamine peptide, and three polyphenol compounds (i.e., tamoxifen, genistein, and verapamil). We employ phase-separated ternary lipid model membranes in the form of giant unilamellar vesicles (GUVs) to simulate raft-like structures that have been proposed to govern many important processes in plasma membranes (e.g., intracellular singling and trafficking). Specifically, we use fluorescent microscopy to interrogate how those membrane additives …

A Randomized, Double-Blind, Placebo-Controlled Phase Ii Trial Investigating The Safety And Immunogenicity Of Modified Vaccinia Ankara Smallpox Vaccine (Mva-Bn®) In 56-80-Year-Old Subjects, Richard N. Greenberg, Christine M. Hay, Jack T. Stapleton, Thomas C. Marbury, Eva Wagner, Eva Kreitmeir, Siegfried Röesch, Alfred Von Krempelhuber, Philip Young, Richard Nichols, Thomas P. Meyer, Darja Schmidt, Josef Weigl, Garth Virgin, Nathaly Arndtz-Wiedemann, Paul Chaplin

Internal Medicine Faculty Publications

Background Modified Vaccinia Ankara MVA-BN^® is a live, highly attenuated, viral vaccine under advanced development as a non-replicating smallpox vaccine. In this Phase II trial, the safety and immunogenicity of Modified Vaccinia Ankara MVA-BN^® (MVA) was assessed in a 56–80 years old population.

Methods MVA with a virus titer of 1 x 10⁸ TCID₅₀/dose was administered via subcutaneous injection to 56–80 year old vaccinia-experienced subjects (N = 120). Subjects received either two injections of MVA (MM group) or one injection of Placebo and one injection of MVA (PM group) four weeks apart. Safety was evaluated …

Identification Of Ecdysone Hormone Receptor Agonists As A Therapeutic Approach For Treating Filarial Infections, Amruta S Mhashilkar, Sai L Vankayala, Canhui Liu, Fiona Kearns, Priyanka Mehrotra, George Tzertzinis, Subba R Palli, H. Lee Woodcock Iii, Thomas R Unnasch

Chemistry Faculty Publications

BACKGROUND: A homologue of the ecdysone receptor has previously been identified in human filarial parasites. As the ecdysone receptor is not found in vertebrates, it and the regulatory pathways it controls represent attractive potential chemotherapeutic targets.

METHODOLOGY/ PRINCIPAL FINDINGS: Administration of 20-hydroxyecdysone to gerbils infected with B. malayi infective larvae disrupted their development to adult stage parasites. A stable mammalian cell line was created incorporating the B. malayi ecdysone receptor ligand-binding domain, its heterodimer partner and a secreted luciferase reporter in HEK293 cells. This was employed to screen a series of ecdysone agonist, identifying seven agonists active at sub-micromolar concentrations. …

Stochastic Processes And Their Applications To Change Point Detection Problems, Heng Yang

Dissertations, Theses, and Capstone Projects

This dissertation addresses the change point detection problem when either the post-change distribution has uncertainty or the post-change distribution is time inhomogeneous. In the case of post-change distribution uncertainty, attention is drawn to the construction of a family of composite stopping times. It is shown that the proposed composite stopping time has third order optimality in the detection problem with Wiener observations and also provides information to distinguish the different values of post-change drift. In the case of post-change distribution uncertainty, a computationally efficient decision rule with low-complexity based on Cumulative Sum (CUSUM) algorithm is also introduced. In the time …

Putting Prep Into Practice: Lessons Learned From Early-Adopting U.S. Providers' Firsthand Experiences Providing Hiv Pre-Exposure Prophylaxis And Associated Care, S. K. Calabrese, Manya Magnus, K. H. Mayer, D. S. Krakower, A. I. Eldahan, L. A. Gaston Hawkins, +5 Additional Authors

Epidemiology Faculty Publications

Optimizing access to HIV pre-exposure prophylaxis (PrEP), an evidence-based HIV prevention resource, requires expanding healthcare providers' adoption of PrEP into clinical practice. This qualitative study explored PrEP providers' firsthand experiences relative to six commonly-cited barriers to prescription-financial coverage, implementation logistics, eligibility determination, adherence concerns, side effects, and anticipated behavior change (risk compensation)-as well as their recommendations for training PrEP-inexperienced providers. U.S.-based PrEP providers were recruited via direct outreach and referral from colleagues and other participants (2014-2015). One-on-one interviews were conducted in person or by phone, transcribed, and analyzed. The sample (n = 18) primarily practiced in the Northeastern (67%) or …

Upper, Lower Solutions And Analytic Semigroups For A Model With Diffusion, Yannick T. Kouakep

Applications and Applied Mathematics: An International Journal (AAM)

In this discussion we consider an autonomous parabolic epidemic 2-dimensional system modelling the dynamics of transmission of immunizing diseases for a closed population into bounded regular domain. Our model takes into account diffusion of population with external influx as well as one class of infected individuals. We study the well-posedness two-component diffusion equations including external supplies with Neumann conditions using upper/lower solutions and analytic semigroups. In case of constant population or not, with non-oscillatory solution and constant diffusion, this problem admits travelling wave solutions whose minimum wave speed is surveyed here.

N-Terminal Domains Of Copper Atpases In Plasmodium Falciparum, Dictyostelium Dicsoideum, Human Atp7b And A Chimera Of Atox1 With Metal Binding Domain Four Of Atp7b, Javan Kilango Kisaka

Dissertations

Copper transporting ATPases (Cu-ATPases) are essential for mediating copper uptake, maintaining cellular copper levels and prevention of accumulation of toxic copper. The most studied copper ATPases are the Menkes and Wilson proteins in eukaryotes, CopA and CopB found in bacteria. The precise interaction of the metal binding domains with their copper donor, the association of each metal binding domain within the N-terminal portion of the protein, how they communicate with each other, and the eventual metal ion translocation across the membrane, is little known. The variation in number of the cytosolic metal binding domains may also offer clues on the …

Screening The Low Molecular Weight Fraction Of Human Serum Using Atr-Ir Spectroscopy, Franck Bonnier, Matthew J. Baker, Hugh Byrne

Articles

Vibrational spectroscopic techniques can detect small variations in molecular content, linked with disease, showing promise for screening and early diagnosis. Biological fluids, particularly blood serum, are potentially valuable for diagnosis purposes. The so-called Low Molecular Weight Fraction (LMWF) contains the associated peptidome and metabolome and has been identified as potentially the most relevant molecular population for disease-associated biomarker research. Although vibrational spectroscopy can deliver a specific chemical fingerprint of the samples, the High Molecular Weight Fraction (HMWF), composed of the most abundant serum proteins, strongly dominates the response and ultimately makes the detection of minor spectral variations a challenging task. …

Identification And Use Of Indicator Data To Develop Models For Marine-Sourced Risks In Massachusetts Bay, Marin M. Kress

Graduate Doctoral Dissertations

The coastal watersheds around Massachusetts Bay are home to millions of people, many of whom recreate in coastal waters and consume locally harvested shellfish. Epidemiological data on food-borne illness and illnesses associated with recreational water exposure are known to be incomplete. Of major food categories, seafood has the highest recorded rate of associated foodborne illness. In total, the health impacts from these marine-sourced risks are estimated to cost millions of dollars each year in medical expenses or lost productivity. When recorded epidemiological data is incomplete it may be possible to estimate abundance or prevalence of specific pathogens or toxins in …

Husband’S Support Towards Unmet Need Of Hiv Positive-Infected Women Of Childbearing Age, Sophia Sophia, Anita Deborah Anwar, Bony Wiem Lestari

Kesmas

Jutaan wanita usia subur (WUS) dengan HIV positif di negara berkembang saat ini tidak menggunakan kontrasepsi untuk menunda atau mengakhiri kehamilan. Pencegahan kehamilan yang tidak diinginkan pada WUS dengan HIV positif sangat penting untuk meningkatkan kualitas hidup ibu dan anak. Tujuan penelitian ini untuk menganalisis faktor-faktor yang berpengaruh terhadap unmet need pada WUS dengan HIV positif. Metode penelitian adalah cross sectional dengan sampel berjumlah 130 WUS dengan HIV positif yang diambil secara consecutive sampling. Penelitian dilakukan pada 24 Maret - 30 Juni 2015 di Klinik Mawar Kota Bandung. Pengumpulan data dilakukan melalui wawancara dengan menggunakan kuesioner, kemudian data dianalisis dengan …

A Multi-Level Model Of Synergistic T Cell Activation, Anna Konstorum, Anthony Vella, Reinhard C. Laubenbacher

Biology and Medicine Through Mathematics Conference

No abstract provided.

Anticipating Elimination Of Mosquito-Borne Diseases, Suzanne M. O'Regan, Jonathan Lillie, John M. Drake

Biology and Medicine Through Mathematics Conference

No abstract provided.

Toward Adaptive Control Of Acute Inflammation, Judy D. Day, Seddik M. Djouadi, Ouassim Bara, Gregory L. Zitelli

Biology and Medicine Through Mathematics Conference

No abstract provided.

Mathematical Modeling Of Endotoxin-Induced Inflammation In Young Men, Renee Brady

Biology and Medicine Through Mathematics Conference

No abstract provided.

Mathematical Models Of Hiv And Hpv Coinfection, Samantha Erwin, Meghna Verma, Vida Abedi, Raquel Hontecillas-Magarzo, Stefan Hoops, Josep Bassaganya-Riera, Stanca M. Ciupe

Biology and Medicine Through Mathematics Conference

No abstract provided.