Advances in saccular aneurysm biomechanics : enlargement via rate-sensitive inelastic growth, bio-mathematical stages of aneurysm disease, and initiation profiles.

I have created the first simulation of saccular aneurysm initiation and development from a healthy artery geometry. It is capable of growing saccular aneurysm geometries from patient-specific data. My model describes aneurysm behavior in a way that bridges fields. I assume arteries are made of a rate-sensitive inelastic material which produces irreversible deformation when it is overstressed. The material is assumed to consist of a 3D hyperelastic background material embedded with 1D transversely-isotropic fibers. I optionally use a Winkler foundation term to model support of external organs and distinguish healthy tissue from diseased tissue. Lesions are defined as a local degradation of artery wall structure. My work suggests passive mechanisms of growth are insufficient for predicting saccular aneurysms. Furthermore, I identify a new concept of stages of aneurysm disease. The stages connect mathematical descriptions of the simulation with clinically-relevant changes in the modeled aneurysm. They provide an evocative framework through which clinical descriptions of arteries can be neatly matched with mathematical features of the model. The framework gives a common language of concepts---e.g., collagen fiber, pseudoelastic limit, inelastic strain, and subclinical lesion---through which researchers in different fields, with different terminologies, can engage in an ongoing dialog: under the model, questions in medicine can be translated into equivalent questions in mathematics. A new stage of “subclinical lesion” has been identified, with a suggested direction for future biomechanics research into early detection and treatment of aneurysms. This stage defines a preclinical aneurysm-producing lesion which occurs before any artery dilatation. It is a stage of aneurysm development involving microstructural changes in artery wall makeup. Under the model, this stage can be identified by its reduced strength: its structural support is still within normal limits, but presumably would perform more poorly in ex vivo failure testing than healthy tissue from the same individual. I encourage clinicians and biomechanicians to measure elastin degradation, and to build detailed multiscale models of elastin degradation profiles as functions of aging and tortuosity; and similarly for basal tone. I hope such measurements will to lead to early detection and treatment of aneurysms. I give specific suggestions of biological tissue experiments to be performed for improving and reinforming constitutive modeling techniques.Mechanical Engineerin

An expert system for ultrasonic flaw classification

This thesis describes the results of a research program which focused on the use of artificial intelligence techniques to solve a problem in the domain of nondestructive evaluation (NDE). The work was performed at the Center for Nondestructive Evaluation at Iowa State University under the supervision of Dr. Charles Wright, Department of Electrical Engineering and Computer Engineering, and Dr. Lester Schmerr, Department of Engineering Science and Mechanics

Teachers\u27 Evidence-Based Practices for Reading Deficiencies

The problem investigated in this study was that students at a rural elementary school in the midwestern region of the United States were not meeting achievement targets in reading on state standardized tests despite implementation of the district\u27s evidence-based reading curriculum. With a conceptual framework based on Webb\u27s depth-of-knowledge model and Piaget\u27s sociocultural learning theory, the purpose of this single case study was to explore teachers\u27 perceptions regarding the use of evidence-based teaching practices and how those practices influence students\u27 reading skills. Using purposeful sampling to select licensed, experienced participants, the insights of 7 elementary reading teachers were collected through semistructured interviews and classroom observations of their instructional practices. Emergent themes were identified through open coding, and the findings were developed and checked for trustworthiness through triangulation and member checking. The findings revealed that teachers appropriately implemented the district\u27s curriculum and recognized the need for evidence-based reading practices. Teachers acknowledged that the district\u27s curriculum did not work for all students and that specialized strategies and resources were needed to reach students who were struggling with reading. A professional development project was created to assist teachers with identifying, assessing, and implementing specialized evidence-based reading strategies and resources. This study has implications for positive social change by providing a structure for teachers to build a repertoire of evidence-based strategies and resources to offer all elementary students, including struggling readers, improved reading instruction, and higher reading achievement

Development of Lateral Flow Fluorescence Assay for the Detection of Trypanosoma

Trypanosoma such as Trypanosoma brucei and Trypanosoma cruzi, the causative agents for African sleeping sickness and Chagas disease, respectively, have important influence on human health. The methods such as microscopic examination, immunological methods, and molecular methods are used for the identification and detection of Trypanosoma, but none of these methods are ideal to mass screening of samples such as onset of outbreak, epidemiological surveys, and blood unit screening. Therefore, there is a need for an assay which can rapidly, sensitively and specifically detect Trypanosoma. In this study, Ru(bpy)32+-doped silica nanoparticles (RuSNP) were used to target nucleic acid sequences in a lateral flow fluorescent assay. This assay was developed to improve the sensitivity and lower the limit of detection as compared to the traditional lateral flow assay. The assay targeted both the spliced leader sequence as well as the polyA tail of the mRNA. The surface of spherical RuSNP was modified by glycidoxypropyl trimethoxysilane (GOPTMS). Amine-terminated oligonucleotides as a bioreceptor were immobilized onto the RuSNP via the interaction between the NH2 and the epoxy group of the GOPTMS. The conjugate complexes formed were immobilized on the conjugate pad, and the capture oligonucleotides used for test and control lines were immobilized on the nitrocellulose membrane. The effects of the amount of RuSNP, GOPTMS, amine-capped oligonucleotides, and capture oligonucleotides on the test line on the performance of the test strips were investigated and optimized. The fluorescence intensity was evaluated by using a fluorescent microplate reader. The experimental results showed that the nucleic acid sequence-based and RuSNP-labeled lateral flow assay was very sensitive compared with the gold-labeled test strips and the chemiluminescent test strips we developed previously, and that the limit of detection (LOD) of the test strips developed is 0.4 fmol. The LOD can further be reduced about one order of magnitude when dipstick format was used

IDA: An Architecture for an Intelligent Design Assistant for Assessing the Inspectability of Structures from a Description of Their Geometry

A program in integrated design, NDE, and the manufacturing sciences at the Center for Nondestructive Evaluation is developing a system that assesses the inspectability and reliability of mechanical structures from a description of their geometry, materials, and performance requirements. Part of this effort involves using techniques of artificial intelligence (AI) to integrate the various components. An Intelligent Design Assistant (IDA) couples the design team to CAD, stress, inspectability and reliability models and provides expert advice on how to improve the performance and reliability of the manufactured part

Development of an Electrowetting Valve in Capillary-Driven Microfluidic Biosensor for Nucleic Acid Detection

This article presents the development of microfluidic valves to be used in capillary flow microfluidic device as a platform for nucleic acid detection. The valve used the principle of electrowetting and was able to be actuated at low voltage. The valve consisted of two silver electrodes which were encountered in series within a microfluidic channel. The second electrode was modified with a hydrophobic monolayer resulting in a cessation of capillary flow. A potential of 4V resulted in a 70° reduction in water contact angle within ten seconds which allowed capillary flow to continue. The final device represented a microfluidic valve for capillary flow microfluidics realized on PMMA substrate. In addition to the valve designed for timed fluid delivery, our PMMA microfluidic chip also consists of self-priming microfluidics with sealed conjugate pads of reagent delivery and an absorbent pad for additional fluid draw. We have developed a single-step surface modification method which allows strong capillary flow within a sealed microchannel. Conjugate pads within the device held trapped complex consisting of the magnetic beads and nucleic-acid-probe-conjugated horseradish peroxidase (HRP). Magnetic beads were released when sample entered the chamber and hybridized with the complex. The complex was immobilized over a magnet in the capture zone while a luminol co-reactant stream containing H2O2 was merged with the channel. A photomultiplier tube was used to quantify the chemiluminescence signal. This new format of biosensor will not only allow for pumpless automatically reagent delivery, but also smaller and more sensitive detection, as well as commercial-scale manufacturing and low materials cost, and it would be an ideal device for fast diagnostic in resource-limited settings

Phage based electrochemical detection of Escherichia coli in drinking water using affinity reporter probes

The monitoring of drinking water for indicators of fecal contamination is crucial for ensuring a safe supply. In this study, a novel electrochemical method was developed for the rapid and sensitive detection of Escherichia coli (E. coli) in drinking water. This strategy is based on the use of engineered bacteriophages (phages) to separate and concentrate target E. coli when conjugated with magnetic beads, and to facilitate the detection by expressing gold binding peptides fused alkaline phosphatase (GBPs-ALP). The fusion protein GBPs-ALP has both the enzymatic activity and the ability to directly bind onto a gold surface. This binding-peptide mediated immobilization method provided a novel and simple approach to immobilize proteins on a solid surface, requiring no post-translational modifications. The concentration of E. coli was determined by measuring the activity of the ALP on gold electrodes electrochemically using linear sweep voltammetry (LSV). This approach was successfully applied in the detection of E. coli in drinking water. We were able to detect 105 CFU mL−1 of E. coli within 4 hours. After 9 hours of preincubation, 1 CFU of E. coli in 100 mL of drinking water was detected with a total assay time of 12 hours. This approach compares favorably to the current EPA method and has the potential to be applied to detect different bacteria in other food matrices

Implementation of Competency Based Educational Strategies into a First-Year Seminar for InterProfessional Healthcare Science Majors

ABSTRACT Introduction: The Health Educators Academy at Western Carolina University was developed by the Dean of the College of Health and Human Sciences. Interdisciplinary fellows in the 2015 HEA focused on competency based education (CBE), which naturally incentivizes collaborative, interdisciplinary and interprofessional work. The 2015 Health Educator Academy Fellows researched healthcare competencies and designed curriculum changes that aligned within these parameters. This article discusses the creation of a first-year, interprofessional healthcare course that emphasizes CBE as well as interprofessional practice. Interprofessional Goals: The 2015 Academy Fellows believed that a collaborative course in the first-year curriculum that builds upon integral competencies would help introduce a structure that would support further IPE in later courses. Background of CBE: The recent expansion of CBE in higher education is a result of a number of factors, including changing demographics, the increase in student debt, declining state funding, and the need for accountability markers and improved learning outcomes. First- Year Experience: First-year seminars were first designed to ease the transition to college for students and to increase both retention and persistence to graduation. Proposed CBE Course: Three foundational interprofessional global health competencies domains were implemented into the first-year experience course: collaboration, partnering and communication; ethics; and sociocultural and political awareness. Reflection and Lessons Learned: In reflecting upon the process of designing a first-year interprofessional, competency-based course, the members of the Health Educator Academy organically implemented many educator and curricular best practices that facilitate collaboration in health care delivery. Future Plans: Rather than deal with complex health issues from a single, specialized approach, healthcare providers will need to work as a team to meet the needs of patients as well as the broader community. Courses such as a first-year seminar based on interprofessional competency-based curriculum can begin the process of teaching students to think collaboratively and critically. This type of course will provide some of the tools that students will need once they leave the university and enter the professional realm