Physical Sciences and Mathematics Commons^™

Protein Structure Classification And Loop Modeling Using Multiple Ramachandran Distributions, Seyed Morteza Najibi, Mehdi Maadooliat, Lan Zhou, Jianhua Z. Huang, Xin Gao

Mathematics, Statistics and Computer Science Faculty Research and Publications

Recently, the study of protein structures using angular representations has attracted much attention among structural biologists. The main challenge is how to efficiently model the continuous conformational space of the protein structures based on the differences and similarities between different Ramachandran plots. Despite the presence of statistical methods for modeling angular data of proteins, there is still a substantial need for more sophisticated and faster statistical tools to model the large-scale circular datasets. To address this need, we have developed a nonparametric method for collective estimation of multiple bivariate density functions for a collection of populations of protein backbone angles. …

Untangling The Most Probable Role For Vitamin D3 In Autism, Dianne E. Godar, Stephen J. Merrill

Mathematics, Statistics and Computer Science Faculty Research and Publications

Recent studies indicate an important role for vitamin D₃ in autism spectrum disorder (ASD), although its mechanism is not completely understood. The most puzzling aspect of ASD is that identical twins, who share identical DNA, do not have 100% concordance rates (∼88% for identical and ∼31% for fraternal twins). These findings provide major clues into the etiology: ASD must involve an environmental factor present in the prenatal milieu that both identical twins are not always exposed to because they do not always share it (i.e., placentas). Combined with the exponential increasing rates of ASD around the world, these observations …

Mapping The Stk4/Hippo Signaling Network In Prostate Cancer Cell, Damien Ready, Kader Yagiz, Pooneh Amin, Yuksel Yildiz, Vincent Funari, Serdar Bozdag, Bekir Cinar

Mathematics, Statistics and Computer Science Faculty Research and Publications

Dysregulation of MST1/STK4, a key kinase component of the Hippo-YAP pathway, is linked to the etiology of many cancers with poor prognosis. However, how STK4 restricts the emergence of aggressive cancer remains elusive. Here, we investigated the effects of STK4, primarily localized in the cytoplasm, lipid raft, and nucleus, on cell growth and gene expression in aggressive prostate cancer. We demonstrated that lipid raft and nuclear STK4 had superior suppressive effects on cell growth in vitro and in vivo compared with cytoplasmic STK4. Using RNA sequencing and bioinformatics analysis, we identified several differentially expressed (DE) genes that responded to ectopic …

All Sites But Skin Cancer Incidences Analyzed Worldwide By Sex, Age, And Skin Type Over Time (1955-2007), Advancing Age, And Uvb Dose Reveals Important Carcinogenic Drivers, Dianne E. Godar, Rossen Gurov, Stephen Merrill

Mathematics, Statistics and Computer Science Faculty Research and Publications

Because we observed increasing incidences over time, advancing age, higher estrogen levels, decreasing UVB (290-315 nm) doses, or lower vitamin D₃, and Human Papillomavirus hiding in immune-privileged sites of hair follicles play roles in melanoma, we wondered if the majority of cancers might have similar carcinogenic drivers. To investigate this possibility, we performed worldwide analysis of all sites but skin cancer over time (1955-2007), advancing age, and UVB doses for males and females with all skin types and ages (0-85+) and in five age groups using IARC data. To investigate Human Papillomavirus’s role, we analyzed the incidences of …

Cutaneous Malignant Melanoma Incidences Analyzed Worldwide By Skin Type Over Advancing Age Of Males And Females: Evidence Estrogen And Androgenic Hair Are Risk Factors, Dianne E. Godar, Madhan Subramanian, Stephen Merrill

Mathematics, Statistics and Computer Science Faculty Research and Publications

We previously analyzed cutaneous malignant melanoma (CMM) incidences worldwide by sex, age, and Fitzpatrick skin type over time (1955-2007) and found only European-ancestry populations have exponential increasing incidences and about a 2-log increase in the risk between the youngest age groups (0-14 and 15-29 yr). We proposed the increasing incidence over time may be from the spread of Human Papilloma Virus (HPV) found in CMM biopsies, and that the 2-log incidence increase between the youngest age groups might be from developing androgenic hair. The increasing incidence with age may be from white hairs transmitting UV radiation to follicular melanocytes. Here …

Some Extended Classes Of Distributions: Characterizations And Properties, Gholamhossein G. Hamedani, Gauss M. Cordeiro, M. C.S. Lima, A. D.C. Nascimento

Mathematics, Statistics and Computer Science Faculty Research and Publications

Based on a simple relationship between two truncated moments and certain functions of the th order statistic, we characterize some extended classes of distributions recently proposed in the statistical literature, videlicet Beta-G, Gamma-G, Kumaraswamy-G and McDonald-G. Several properties of these extended classes and some special cases are discussed. We compare these classes in terms of goodness-of-fit criteria using some baseline distributions by means of two real data sets.

A Short Note On The Paper: "New Characterizations Of The Pareto Distribution", Gholamhossein G. Hamedani, M. Rasekhi

Mathematics, Statistics and Computer Science Faculty Research and Publications

Nofal and El Gebaly (2017), presented certain characterizations of the Pareto distribution based on the conditional expectations of power of the order statistics. In this short note we show that the same results can easily be obtained in terms of the power of the random variable.

Privacy Vulnerabilities In The Practices Of Repairing Broken Digital Artifacts In Bangladesh, Syed Ishtiaque Ahmed, Shion Guha, Mohammad Rashidujjaman Rifat, Faysal Hossain Shezan, Nicola Dell

Mathematics, Statistics and Computer Science Faculty Research and Publications

This paper presents a study on the privacy concerns associated with the practice of repairing broken digital objects in Bangladesh. Historically, repair of old or broken technologies has received less attention in ICTD scholarship than design, development, or use. As a result, the potential privacy risks associated with repair practices have remained mostly unaddressed. This paper describes our three-month long ethnographic study that took place at ten major repair sites in Dhaka, Bangladesh. We show a variety of ways in which the privacy of an individual’s personal data may be compromised during the repair process. We also examine people’s perceptions …

K-8 Pre-Service Teachers’ Algebraic Thinking: Exploring The Habit Of Mind Building Rules To Represent Functions, Marta T. Magiera, John C. Moyer, Leigh A. Van Den Kieboom

Mathematics, Statistics and Computer Science Faculty Research and Publications

In this study, through the lens of the algebraic habit of mind Building Rules to Represent Functions, we examined 18 pre-service middle school teachers' ability to use algebraic thinking to solve problems. The data revealed that pre-service teachers' ability to use different features of the habit of mind Building Rules to Represent Functions varied across the features. Significant correlations existed between 8 pairs of the features. The ability to justify a rule was the weakest of the seven features and it was correlated with the ability to chunk information. Implications for mathematics teacher education are discussed.

Xinupi3: Teaching Multicore Concepts Using Embedded Xinu, Priva Bansal, Rade Latinovich, Tom Lazar, Patrick J. Mcgee, Dennis Brylow

Mathematics, Statistics and Computer Science Faculty Research and Publications

As computer platforms become more advanced, the need to teach advanced computing concepts grows accordingly. This paper addresses one such need by presenting XinuPi3, a port of the lightweight instructional operating system Embedded Xinu to the Raspberry Pi 3. The Raspberry Pi 3 improves upon previous generations of inexpensive, credit card-sized computers by including a quad-core, ARM-based processor, opening the door for educators to demonstrate essential aspects of modern computing like inter-core communication and genuine concurrency.

Embedded Xinu has proven to be an effective teaching tool for demonstrating low-level concepts on single-core platforms, and it is currently used to …

Pattern Containment In Circular Permutations, Charles Lanning

Electronic Theses and Dissertations

Pattern containment in permutations, as opposed to pattern avoidance, involves two aspects. The first is to contain every pattern at least once from a given set, known as finding superpatterns; while the second is to contain some given pattern as many times as possible, known as pattern packing. In this thesis, we explore these two questions in circular permutations and present some interesting observations. We also raise some questions and propose some directions for future study.

Investigation Of The Effects Of Ionic Interactions In Peptide And Protein Structure, Aimee Lorts

Electronic Theses and Dissertations

Proteins and their unique structures are important due to their involvement in every cellular task, but the protein can only function properly when it is in the correct fold. β-sheet peptides and collagen were observed via structural studies. Circular dichroism (CD) determines a protein’s secondary structure. WKWK, a beta-sheet peptide, is known to dissolve in aqueous solutions. However, WKWK was observed to precipitate out of deionized water. To investigate the cause of this precipitation, Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) was used to determine the ion content of the water. Elevated sodium ion concentrations were found to disrupt the stabilizing …

ปัจจัยที่มีผลต่อความตั้งใจในการกลับมาใช้ซ้ำและความตั้งใจในการบอกต่อของแอพพลิเคชันที่ใช้เทคโนโลยีความเป็นจริงเสริม กรณีศึกษา: แอพพลิเคชันอัตราแลกเปลี่ยนสกุลเงินต่างประเทศในอาเซียน, ปุณพีร์ สิทธิกิจ

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์หลักเพื่อวิเคราะห์ปัจจัยที่น่าจะส่งผลต่อความตั้งใจในการกลับมาใช้ซ้ำและความตั้งใจในการบอกต่อของแอพพลิเคชันที่ใช้เทคโนโลยีความเป็นจริงเสริม ได้แก่ (1) การรับรู้ความง่าย (2) การรับรู้ประโยชน์ (3) การรับรู้ความสนุกสนาน (4) การรู้สึกจดจ่อ (5) การมีปฏิสัมพันธ์ โดยมีตัวแปรกำกับคือ เจเนอเรชัน และเพศ เพื่อให้ได้ผลที่ครอบคลุมและหลากหลายงาน วิจัยนี้ได้แบ่งกลุ่มตัวอย่างที่จะศึกษา ออกเป็น เพศชายและเพศหญิง และ แบ่งตามเจเนอเรชันซึ่งได้แก่ เจเนอเรชัน X, เจเนอเรชัน Y และเจเนอเรชัน Z งานวิจัยนี้เป็นงานวิจัยเชิงทดลอง (Experimental Research) ซึ่งมีเครื่องมือที่ใช้ในการเก็บข้อมูลได้แก่ โมไบล์แอพพลิเคชันเทคโนโลยีความเป็นจริงเสริม ข้อมูลเก็บจากกลุ่มตัวอย่างจำนวน 240 คน ที่ได้ทดลองใช้แอพพลิเคชันที่ใช้เทคโนโลยีความเป็นจริงเสริมและตอบแบบสอบถามที่ผู้วิจัยจัดเตรียมไว้ ผลการวิเคราะห์ข้อมูลพบว่าปัจจัยด้านการรับรู้ความง่ายในการใช้งาน การรับรู้ประโยชน์ การรับรู้ความสนุกสนาน การรู้สึกจดจ่อและการมีปฏิสัมพันธ์มีความสัมพันธ์เชิงบวกกับความตั้งใจในการกลับมาใช้ซ้ำและความตั้งใจในการบอกต่อ โดยในภาพรวมพบว่า การรับรู้ความง่ายมีความสัมพันธ์มากที่สุดกับความตั้งใจในการกลับมาใช้ซ้ำ การรับรู้ประโยชน์ มีความสัมพันธ์มากที่สุดกับความตั้งใจในการบอกต่อ ในกรณีที่เพศและเจเนอเรชันของผู้ใช้ต่างกันพบว่ามีความสัมพันธ์เชิงบวกกับความตั้งใจในการกลับมาใช้ซ้ำและความตั้งใจในการบอกต่อเช่นกัน สำหรับเพศชาย พบว่าการรับรู้ความง่ายมีความสัมพันธ์กับความตั้งใจในการกลับมาใช้ซ้ำมากที่สุด และการมีปฏิสัมพันธ์มีความสัมพันธ์กับความตั้งใจในการบอกต่อมากที่สุด ในกรณีเพศหญิงพบว่า ปัจจัยด้านการรับรู้ประโยชน์มีความสัมพันธ์มากที่สุดทั้งกับความตั้งใจในการกลับมาใช้ซ้ำและความตั้งใจในการบอกต่อ ในแง่ของเจเนอเรชันผู้ใช้พบว่า เจเนอเรชัน X และเจเนอเรชัน Y การรับรู้ความสนุกสนานมีความสัมพันธ์กับความตั้งใจในการกลับมาใช้ซ้ำและความตั้งใจในการบอกต่อมากที่สุด เจเนอเรชัน Z พบว่า ปัจจัยด้านการรับรู้ความง่ายมีความสัมพันธ์กับความตั้งใจในการกลับมาใช้ซ้ำและความตั้งใจในการบอกต่อมากที่สุด

Approaches Toward Novel 1,2,3-Triazole Sensors For The Detection Of Anions And Heavy Metal Cations, Richard D. Govan

Electronic Theses and Dissertations

Cations and anions play pivotal roles in biological and physiological processes, however an imbalance in concentration of any ion can be detrimental. Therefore, research into the selective recognition of anions and heavy metal cations has acquired much attention. One approach involves the use of chemosensors. Upon interaction with targeted analytes, chemosensors produce a distinct response, in some cases a fluorescent or colorimetric signal. The 1,2,3-triazole unit has much potential as a chemical sensor due to its unique photophysical properties. The specificity, selectivity, and signaling mechanism of triazole sensors can be tuned with conjugation in the motif and choice and placement …

Synthesis And Biological Activity Of Novel Tu100 Derivatives, Oladotun J. Alao

Electronic Theses and Dissertations

In an attempt to create more effective chemotherapeutic compounds, the naphthoquinone adduct, 12,13-dihydro-N-methyl-6,11,13-trioxo-5H-benzo[4,5]cyclohepta [1,2 b]naphthalen-5,12-imine (hereafter called TU100) was synthesized. Inspired by its unique and novel mechanism of action, a series of structural derivatives were synthesized to explore structure-activity relationships. The analogues exhibited different cytotoxicity profiles, revealing the indicated regions are involved in cell death induction. Furthermore, the analogues had dramatically different effects on cellular ATP production, suggesting different molecular targets. Synthesis, biological activity, and SAR study of these analogues will be revealed.

Optimization Methods For Tabular Data Protection, Iryna Petrenko

Electronic Theses and Dissertations

In this thesis we consider a minimum distance Controlled Tabular Adjustment (CTA) model for statistical disclosure limitation (control) of tabular data. The goal of the CTA model is to find the closest safe table to some original tabular data set that contains sensitive information. The measure of closeness is usually measured using l₁ or l₂ norm; with each measure having its advantages and disadvantages. According to the given norm CTA can be formulated as an optimization problem: Liner Programing (LP) for l₁, Quadratic Programing (QP) for l₂. In this thesis we present an alternative …

Applications Of Flow Network Models In Finance, Angel J. Woods

Electronic Theses and Dissertations

In this thesis we explore the applications of flow networks in practical problems in finance. After introducing basic definitions and background information, we first survey some known applications of flow networks in theoretical mathematics. We also briefly comment on their potential applications in the setting of financial flow networks. We then construct networks from practical financial flows and present the construction, reasoning, and known applications. Lastly, we show a design of financial flow networks that takes time into consideration and discuss its applications.

Antibiotics And Antibiotic-Resistant Bacteria In Coastal Plain Streams, Jason Duff

Electronic Theses and Dissertations

Streams across the United States and globally are influenced by environmental contamination, including antibiotics, which enter streams due to widespread use and multiple pathways into the environment. Antibiotics are also likely to enter streams in mixture with other contaminants that alter the effects on aquatic organisms. Furthermore, antibiotic-resistant bacteria enter streams through similar pathways as antibiotics with implications for natural microbial communities. Therefore, understanding the presence and effects of antibiotic-contaminant mixtures and antibiotic-resistant bacteria in streams is important for resource management.

Chapter one describes an experiment that tested the hypothesis that the antibiotic tetracycline (TC) alone influences phytoplankton communities differently …

The Bessel Function, The Hankel Transform And An Application To Differential Equations, Isaac C. Voegtle

Electronic Theses and Dissertations

In this thesis we explore the properties of Bessel functions. Of interest is how they can be applied to partial differential equations using the Hankel transform. We use an example in two dimensions to demonstrate the properties at work as well as formulate thoughts on how to take the results further.

Quasi-Random Action Selection In Markov Decision Processes, Samuel D. Walker

Electronic Theses and Dissertations

In Markov decision processes an operator exploits known data regarding the environment it inhabits. The information exploited is learned from random exploration of the state-action space. This paper proposes to optimize exploration through the implementation of quasi-random sequences in both discrete and continuous state-action spaces. For the discrete case a permutation is applied to the indices of the action space to avoid repetitive behavior. In the continuous case sequences of low discrepancy, such as Halton sequences, are utilized to disperse the actions more uniformly.

Oasis - Identifying The Core Attributes For Rdbms Alternatives, Benjamin P. Mcpherson

Electronic Theses and Dissertations

Since their introduction in the 1970s, relational database management systems have served as the dominate data storage technology. However, the demands of big data and Web 2.0 necessitated a change in the market, sparking the beginning of the NoSQL movement in the late 2000s. NoSQL databases exchanged the relational model and the guaranteed consistency of ACID transactions for improved performance and massive scalability [1]. While the benefits NoSQL provided proved useful, the lack of sufficient SQL functionality presented a major hurdle for organizations which require it to properly operate. It was clear that new RDBMS solutions which did not compromise …

Dynamics Of Gene Networks In Cancer Research, Paul Scott

Electronic Theses and Dissertations

Cancer prevention treatments are being researched to see if an optimized treatment schedule would decrease the likelihood of a person being diagnosed with cancer. To do this we are looking at genes involved in the cell cycle and how they interact with one another. Through each gene expression during the life of a normal cell we get an understanding of the gene interactions and test these against those of a cancerous cell. First we construct a simplified network model of the normal gene network. Once we have this model we translate it into a transition matrix and force changes on …

A Markov Decision Process Approach To Adaptive Contact Strategies, Artur Grygorian

Electronic Theses and Dissertations

In the field of survey methodology, optimizing contact strategies helps organizations increase response rates using their allocated budget. Markov Decision Processes (MDP) are widely used to model decision-making strategies in situations where the outcomes have a random component. In this research, we use MDPs and adaptive sampling techniques to construct a strategy that, based on target audience characteristics, suggests the best contact policy. The data we use comes from the First Destination Survey conducted by the Office of Career Services at Georgia Southern University. The constructed model is quite flexible and can be used by other organizations to optimize their …

Designer Metasurfaces For On Demand Optical Responses, Matthew S. Lepain

Electronic Theses and Dissertations

Nanostructured materials are one of the leading areas in photonics currently. These structures offer almost limitless possibilities in the manipulation of light. Using two different semi-analytical simulation methods, I show a few of the possible properties that these nanostructures possess, including polarization rotation and coupling with electronics.

Assessment Of Short-Term Toxicity Of Titanium Dioxide Nano Fiber (Tdnf) In Sprague Dawley Rats, Daniel A. Hunter

Electronic Theses and Dissertations

Nanotechnology is easily becoming one of the fastest growing markets around the globe. Synthetic nanomaterials have many unique chemical and physical properties, mainly due to their huge specific surface area and chemical makeup. Specifically, titanium dioxide (TiO₂) nanomaterials have high stability, anticorrosive and photocatalytic properties. These nanomaterials have applications for semiconductor photocatalysis, treatment of water, as a photoactive material in nanocrystalline solar cells, and medicine. However, not much is known about the toxicity of TiO₂ in the nanofiber form. The objective of the present study is to investigate the adverse effects associated with acute ingestion of TiO …

Combinatorics Of Compositions, Meghann M. Gibson

Electronic Theses and Dissertations

Integer compositions and related enumeration problems have been extensively studied. The cyclic analogues of such questions, however, have significantly fewer results. In this thesis, we follow the cyclic construction of Flajolet and Soria to obtain generating functions for cyclic compositions and n-color cyclic compositions with various restrictions. With these generating functions we present some statistics and asymptotic formulas for the number of compositions and parts in such compositions. Combinatorial explanations are also provided for many of the enumerative observations presented.

Photodynamic Cancer Therapy A Study Of The Photochemical Properties Of Meso-Tetra (2,3,4-Trifluorophenyl) Porphyrin And Meso-Tetra (2,3,5,6-Tetrafluorophenyl) Porphyrin, Delanie L. Newberry

Honors College Theses

Photodynamic therapy(PDT) is a type of cancer treatment that utilizes photosensitive molecules that absorb photons and use that energy to create cytotoxic molecules. Porphyrins are photosensitive compounds that can be used selectively at the site of cancerous tumors. Their selectivity is due to the fact the porphyrins are generally not toxic in absence of light; in the presence of light, the drug will be activated to produce the cytotoxic molecule, singlet oxygen(1O2 ). 9,10 diphenyl anthracene(DPA) was used to simulate the cancer cells and monitor how effective the porphyrin was in creating 1O2, because DPA reacts with 1O2 form diphenyl …

Iodine-Initiated Hydration Of Internal Alkynes, Nicholas J. Shuber, Karelle Aiken

Honors College Theses

The iodine-initiated hydration of internal alkynes is a novel, green, and inexpensive synthetic pathway in comparison with the commonly used transition metal catalyzed reactions. This can be a useful alternative in many fields, academic or industrial. This experimental design has been used successfully on terminal alkynes and is now being extended to internal alkynes. Through systematic probing of the reaction conditions, we have gleaned sufficient information to determine a strong mechanistic hypothesis based on neighboring group participation. Here in, we will report our result with a series of internal, keto alkynes reacted under ambient conditions with iodine in “wet” solvent. …

Rotational Symmetry Breaking In A Trigonal Superconductor Nb-Doped Bi₂Se₃, T. Asaba, B. J. Lawson, C. Tinsman, L. Chen, P. Corbae, G. Li, Y. Qiu, Yew San Hor, L. Fu, L. Li

Physics Faculty Research & Creative Works

The search for unconventional superconductivity has been focused on materials with strong spin-orbit coupling and unique crystal lattices. Doped bismuth selenide (Bi₂Se₃) is a strong candidate, given the topological insulator nature of the parent compound and its triangular lattice. The coupling between the physical properties in the superconducting state and its underlying crystal symmetry is a crucial test for unconventional superconductivity. In this paper, we report direct evidence that the superconducting magnetic response couples strongly to the underlying trigonal crystal symmetry in the recently discovered superconductor with trigonal crystal structure, niobium (Nb)-doped Bi₂Se_{3 …}

Textured Nise₂ Film: Bifunctional Electrocatalyst For Full Water Splitting At Remarkably Low Overpotential With High Energy Efficiency, Abdurazag T. Swesi, Jahangir Masud, Wipula P. R. Liyanage, Siddesh Umapathi, Eric W. Bohannan, Julia E. Medvedeva, Manashi Nath

Physics Faculty Research & Creative Works

Herein we have shown that electrodeposited NiSe₂ can be used as a bifunctional electrocatalyst under alkaline conditions to split water at very low potential by catalyzing both oxygen evolution and hydrogen evolution reactions at anode and cathode, respectively, achieving a very high electrolysis energy efficiency exceeding 80% at considerably high current densities (100 mA cm^-2). The OER catalytic activity as well as electrolysis energy efficiency surpasses any previously reported OER electrocatalyst in alkaline medium and energy efficiency of an electrolyzer using state-of-the-art Pt and RuO₂ as the HER and OER catalyst, respectively. Through detailed electrochemical and …