Sixty-eight CSU undergraduate students had the opportunity to work on research projects with faculty mentors during Summer 2014. Fifty-seven proposals were received from five colleges with requests totaling $460,754. With the generous support of the Provost's office, 33 proposals were funded across 16 departments for a total of $249,838. The Fall 2014 Undergraduate Research Poster Session took place on September 4, 2014 from 10am - 2pm in the Student Center Atrium. Students, faculty, and staff were invited to attend the poster session, which provided students the opportunity to discuss their research with the CSU community.
Selection of an Eevolved Orthogonal Ne-Acetyllysine tRNAsynthetase that can Incorporate the Unnantural Amino Acid L-homocitrulline Site-specifically into Proteins
Jaclyn Alatrash, Camelia Baleanu Gogonea, Stanly L. Hazen, and Joseph DiDonato
Oxidatively damaged apolipoprotein A1 (apoA1, the main protein constituent of high density lipoprotein (HDL) - the “good cholesterol”) has been isolated from circulating plasma and atherosclerosis plaque with modification of lysine amino acid residues to homocittruline (carbamyllysine) in apoA1 identified as a modification found increased in smokers that correlates with elevated cardiovascular risk for myocardial infarction (MI), stoke or death. The selected carbamyllysine tRNA synthetase will then be used to express a series of human apoA1 alleles containing amber codons in place of various lysine residues and assayed for its ability to form nascent HDL particles and to activate NF-κB and vascular adhesion molecule expression on endothelial cells.
Individual clones from this round of selection will be isolated and tested the clone encoding the synthase which best incorporates carbamyllysine at the lowest uAA concentration. The selected carbamyllysine tRNA synthetase will then be used to express a series of human apoA1 alleles containing amber codons in place of various lysine residues and assayed for its ability to form nascent HDL particles and to activate NF-κB and vascular adhesion molecule expression on endothelial cells.
Morgan Ashcraft, Chunfang Liu, Qiaoyun Zheng, and Aimin Zhou
Macrophage-derived foam cell formation is a milestone of the atherosclerotic lesion initiation and progression, leading to cardiovascular diseases and stroke. Foam cells are formed from the disruption of a homeostatic mechanism that manipulates the uptake, intracellular metabolism and efflux of cholesterol within macrophages. Although studies have yielded much information about the homeostatic mechanism, the molecular basis of foam cell formation remains to be fully understood. We recently found that deficiency of RNase L attenuated macrophage functions including macrophage migration and its endocytic activity. Furthermore, RNase L markedly impacted the expression of certain pro- and anti-foam cell genes in macrophages. Most interestingly we have revealed that lack of RNase L significantly increased the formation of foam cells from bone marrow derived macrophages (BMMs). The increase of foam cell formation was associated with up-regulation of the expression of scavenger receptors such as CD36, SR-A, and PPAR-g. These studies provide new insights into foam cell formation and novel therapeutic strategies for atherosclerosis may be designed through activation/up-regulation of RNase L.
Taylor Barto and Dan Simon
Until recently, leg prostheses (artificial legs) operated similarly to a leg without muscles. With recent advances in electronic technology, motorized prostheses have become possible. However, these prostheses require large batteries and have a limited operation time. Our research focuses on using supercapacitors in prostheses to exploit the braking portion of human walking to regenerate energy, thus reducing the dependence on batteries. To use supercapacitors with the knee motor, electronic control circuitry is required. We are using a circuit that is similar to a standard motor controller to manage the flow of energy between the supercapacitor and the knee motor. This circuit can operate in two primary modes: one mode during motoring, and another mode during braking. Two additional, secondary modes arise depending on the direction the knee is rotating. Real-time switching between these four modes allows the prosthesis to correctly power the motor, and to maximize energy storage during braking. The prosthesis characteristics are optimized with artificial intelligence algorithms. Due to the large amount of computational effort required, the optimization algorithm is performed with parallel computing.
What Drives Asian Descendent Students’ Motivation for Learning? Exploring the Key Ingredients to Nurture Achievement
Melissa Beaune, Yiyin Wang, Mary Gove, and Grace Huang
This motivation project is part of a larger study of exploring the relationship between Asian parenting styles and children’s academic achievement. In light of the consistent Asian students PISA (Programme for International Student Assessment) data results and the media phenomenon created by Amy Chua’s Battle Hymn of the Tiger Mother in 2011 in U.S., our research team found that high motivation has been a reoccurring theme in children’s academic achievement in the perceptions of Asian descendent parents. The purpose of this project is to examine the Asian descendent students’ motivations for learning through the parents’ experiences and perceptions. The research methods include individual interviews and a focus group interview. Eighteen parents, including thirteen mothers and five fathers participated in this study. All participants had at least one child within the ages of 2-20 years old. Based on our findings, four themes have emerged. We learned that these parents nurtured and sustained children’s motivation for learning through the following four ingredients, including resources, communications, setting clear and high expectations, and the modeling of the parents. Implications for educators will be provided in this presentation.
Live Cell Imaging of Bone Marrow Stromal Cells on Nano-pitted and Polished Titanium Surfaces: A Micro-Incubator in vitro Approach
Zakaria Benmerzouga, Surendra Tewari, and Joanne Belovich
Current orthopedic implants are not conducive for optimal integration of the biomaterial with newly-formed tissue (osseointegration) inside a patient’s body. In this study, medical-rade Ti-6Al-4V was used as a substrate due to its biocompatibility and ability to facilitate cellular adhesion and proliferation. Live cell imaging was conducted on bone marrow stromal cells, genetically modified to express the green fluorescent protein (GFP), from the 24-96 hours growth period, with the first 24 hours of growth being held inside a lab-scale incubator. Periodic images were recorded on nanopitted anodized and polished Ti-6Al-4V substrates to study how substratestiffness influences adhesion and proliferation. Collected images were analyzed for mitosis, adhesion, and filopodia-stretchability using ImageJ, an image processing program. Images were enhanced in order to perform cell counts at 24, 48, 72, and 96 hours of growth. Continuous recordings were produced to account for the number of mitosis occurrences and cellular migration on each of the substrates. Based on the conducted experiments, it appears that polished Ti-6Al-4V has a higher cell adherence than “nanopitted” anodized surface and an improved rate of proliferation which may be because the cells once adhered on the nano-pitted surface have less ability to detach in-order to undergo mitosis.
Bartholomew J. Brown, Katherine Florek, and Hanz Richter
A mathematical model was developed for a linear actuator to be used in a powered leg prosthesis. The model consists of a differential equation relating motor voltage, external force and velocity. All model parameters were known from manufacturer's data, except inertia and friction. A numerical simulation was prepared to estimate these parameters from experimental data. Experiments were conducted and a numerical search was performed to arrive at parameter values that closely fit the data. The mathematical model will be used in subsequent control development work.
Tara Burns, Joni Lewanski, Alex Farmer, Kelly McCafferty, Jeffery Allen, Matthew Egizii, Rebecca Fowler, Stephen Morgan, Rafeeq Roberts, Jordan Tobin, and Kimberly Neuendorf
Since MTV's introduction in 1981, music videos have shaped popular culture in various ways. Transitioning from television/cable to online platforms, thousands of music videos are viewed daily by millions through streaming sites such as YouTube and Vimeo. As a collaborative group, we wrote and produced a music video in collaboration with the metal band Lick the Blade, focusing on their original piece, “Blood Soaked Majesty.” Footage was produced for both a performance video, showing only the band performing their piece, and a narrative video, featuring a story line that parallels the lyrics. An audience will be able to view a performance video, a narrative piece, or a “concept” video that links images from the narrative piece with the performance video, without providing a true story line. The produced footage allows us to edit various versions of the music video in order to study different outcomes of music video exposure, with three goals: (1) Compare spectators’ involvement and interpretations for performance vs. narrative video versions; (2) investigate outcomes of different levels of violent content and victim gender; (3) examine the impact on reception of non-synchronous sound editing. Results from these studies could lend insight to producers of music videos.
Oral History, Mobile Curation, and African American Memory in Cleveland's Fairfax and Glenville Neighborhoods
Benne Christian, Willette Crawford, Julie Gabb, J. Mark Souther, and Regennia N. Williams
Fairfax and Glenville are historic neighborhoods with signal importance in the African American community. Too often these neighborhoods are subjected to a simplistic declension narrative that pins their heyday in the 1920s-50s and traces their decline to the convulsive riots of the late 1960s and the subsequent loss of population to the suburbs as middle-class African Americans mirrored “white flight.” Our team conducted over 40 interviews, created story clips, and curated several new sites for the Cleveland Historical website and mobile application. Our research, rooted in oral history, exposed an important post-1968 counternarrative of resilience. Our oral histories demonstrate a continuing thread of black/white/Jewish collaborative approaches to community issues, particularly in Glenville, as well as the continuing relevance of the “old neighborhoods” for work, play, and worship long after middle-class suburban flight. They also reveal a selective memory that privileges personal connections to the neighborhood through kinship, friendship, faith, and social activism, yielding a “sense of place” that is not always tied to prevailing assumptions about the neighborhoods.
Investigating the Impact of the Deeper Learning Curriculum on High School Students' Understanding of Drug Discovery
Gavin T. Custer, Thien Q. Dinh, Yuriy Y. Krasnov, and Robert L. Ferguson
In the summer of 2014, 23 local high school students participated in a pipeline program on the campus of Cleveland State University. The program, entitled “Careers in Health and Medical Professions” (CHAMPS), serves to prepare college-bound students for careers in the medical field. CHAMPS utilizes a simulated drug discovery curriculum based on “Deeper Learning” (Jensen & Nicholsen, 2008) to provide the high school students with authentic hands-on research experience. There are four main goals in this program: increase awareness of medical careers, introduce knowledge related to drug discovery, build on students’ academic skills, and familiarize the students with 21st century skills. Three undergraduate student researchers were assigned to investigate these goals using a variety of methods, including surveys, individual and group interviews, and laboratory observations. General findings include participants were surprised at the source of drugs; their awareness of health and medical careers increased but their specific career did not change; and nearly all of the students possessed a proficient level of inter-personal skills, communication, and technology prowess.
Asymmetrical variation in the trabecular bone within the human lumbar vertebrae of the Libben hunting population
Andrew S. Dickson and Anne Su
Trabecular bone, a porous network of struts found within mammalian bone, has been understood to show regional variations in response to weight bearing activities. In this study, the L4 vertebrae were examined from a population of prehistoric hunters and gatherers, with the hypothesis that the trabecular bone would show left-right asymmetry that may be an indicator of asymmetry in trunk and upper limb use such as during spear throwing. The L4 vertebra of 10 male individuals aged 18-35 were digitally imaged using micro-computed tomography (micro-CT). Trabecular bone properties were quantified in the left and right sides of each vertebral body, then asymmetry determined as the difference. Trabecular bone volume, thickness, and number showed about 10% or less asymmetry. However, anisotropy and elongation, properties that are indicative of the shape and orientation of trabecular struts, showed 35% or greater asymmetry. These results are consistent with other studies that suggest trabecular shape and orientation may be indicators of habitual postural or activity loads. Future studies will explore whether there is a relationship between this asymmetry in the L4 vertebrae and asymmetry in other skeletal indicators of upper limb use (handedness), which may be useful in understanding the evolution of human tool use.
Comparison of Therapeutic Exercise Accuracy During Completion of a Home Exercise Program Using the Exercise Tutor Versus a Written Home Exercise Program
James Flis, Riana Stanko, Megan Stang, Ann Reinthal, and Deborah Espy
Exercise is powerful in rehabilitation and prevention of disability; however, patient adherence to home exercises is difficult, learning new movements requires a great deal of practice, and incorrectly performed exercises are ineffective or even dangerous. We have developed a system comprised of a Kinect device with wearable inertial sensors to capture, record, and process the exerciser’s movement while concurrently providing targeted feedback to guide correct exercise completion. This pilot study allowed us to perform initial testing of this system, specifically, the effectiveness of this system in improving exercise accuracy, with and without the addition of inertial sensors to the Kinect camera feedback, as compared to a traditional written home exercise program. Twenty-four participants (18-48 years old, 14 female) completed one of three training types: a written exercise program, Kinect feedback only, or combined inertial sensor and Kinect feedback. All subjects completed a pre-test, three training sessions, and a post-test with the assigned feedback type, with movement accuracy as the outcome. These data are in analysis; therefore, previous data from the pilot for this project are presented here. Initial analysis indicates that kinect and inertial sensor feedback are better for different movement types, and are superior to a written program.
Incarcerated Mothers: What Role Does Communication Play in Successful Family and Community Reintegration?
Rebecca Fowler, Jill E. Rudd, and Kimberly A. Neuendorf
The Incarcerated Mothers Project (TIFF--Transitioning Incarcerated Females & Families) is a four-tiered investigation into the subject of incarcerated mothers and how communication affects parental dynamics. The first tier of research included an earlier pilot study of 53 incarcerated mother. The second tier involved an experiment assessing the impact of exposure to a documentary narrative about the impact of a mother’s incarceration on her family; results showed significant knowledge gain and empathetic responses among general receivers. This summer, additional footage was added to the documentary, with instrumentation ready for a Fall 2014 data collection. Also this summer, progress was made on the third tier, which involved speaking with various experts and professionals in the field of incarceration and reintegration. These interviews established that both family and community support are vital preventatives toward preventing recidivism. The fourth tier of the project includes developing additional interview questions to continue the pilot study both with the established group of research subjects and extending that research pool for a more expansive data set. Data collected will be used to develop programs in communication, including family communication education modules video education modules for incarcerated and reintegrating populations.
Katie Fry, Rachel Daley, Kyle Riordan, and Phillip J. Wanyerka
In the early 1990’s archaeologists and historians from Cleveland State University and the Cleveland Museum of Natural History explored and excavated an early frontier community located south and east of Public Square in the area known locally as the Central Market District. To most Clevelanders the Central Market District brings to mind the bustle of busy nightclubs or the aging facades of old Cleveland landmarks. Few people, if any, would associate this area with archaeology, let alone remember that from 1796 through the 1860’s this area was home to one of Cleveland’s earliest English and Welsh working-class communities. From the founding of the Central Market in 1856 through the mid-1950’s, this district was a booming commercial area that included groceries, saloons, apothecaries, shoemakers, and other commercial businesses. By the start of the 20th century, this area was the main commercial hub for most of downtown Cleveland. However, by the late-1950’s the businesses in this area began to wither and decline ultimately leading to the demise and abandonment of this once thriving commercial district. Things would dramatically change in the late 1980’s when plans were announced that would revitalize this area with the construction of a new sports-entertainment complex known as Gateway. Today, the Gateway Complex is home to Progressive Field and to Quicken Loans Arena. Presented here on our poster are the results of our summer research which involved a historical examination and investigation of the residential, commercial, and entertainment eras of the Central Market District based on our analysis of more than 100,000 artifacts collected from this area. Our project demonstrates how archaeology can be used as a critical tool in understanding the history and archaeology of Cleveland’s historic Central Market District.
Controlling Micelle Formation Using Mixtures of Linear and Foldon-capped Polypeptides (ELP): Measurements with UV-vis Spectroscopy
John P. Gavin, Michael G. Price, Janna Mino, Nolan Holland, and Kiril Streletzky
Polymer surfactants developed in our lab have a protein headgroup (foldon) and three elastin-like polypeptide (ELP) tails. They can form micelles smaller than 30 nm, which may be useful in developing targeted drug delivery vehicles. Specifically, ELPs are capped with foldon, which is a 27 amino acid sequence that folds as a homotrimer, resulting in a three-armed star polypeptide. This structure has been shown to form micelles above the transition temperature (Tt) of the ELP. The salt concentration affects the interaction between the headgroups affecting how the micelles assemble. At low salt concentrations the ELP-foldon will form spherical micelles; whereas, at higher salt concentrations the micelles are non-spherical, as is demonstrated by light scattering. When linear ELP is mixed with ELP foldon, it is expected that the ELP-foldon will stabilize small droplets of linear ELP in the form of a microemulsion. Different ratios of ELP-foldon to linear ELP were prepared and their transition behavior was characterized using turbidity measured with UV-vis spectroscopy. The turbidity increased at the Tt of the ELP, and then dropped substantially at the Tt of the ELPfoldon. Increased concentration of the linear ELP increased the measured turbidity level after both transitions, suggesting an increase in aggregate size. Light scattering was utilized to further characterize the size and shape of the aggregates formed.
Andrew Gunnerson, Bogdan Olar, and Haodong Wang
We developed an autonomous mobile robot platform capable of following a path and gather environmental data, including temperature, humidity, light intensity, etc. The robot is capable of detecting the path using its camera and correct most navigational errors, while the sensors support a limited set of instructions regarding which sensor data to collect and how often. Our experiment consisted of having the robot follow a looped path we set up in BU004 Lab. The robot was able to complete the loop and gather sensor data for light intensity, humidity and temperature at a frequency of once per second, and also positional data provided by the robot at around the same frequency.
Julia C. Harvey Azzolina, Lois M. Rotuno, April D. Butler Waltonen, and Albert F. Smith
Previous research has shown that there are phenomena that may require a route to word identification by means other than through letters. For example, in a lexical decision task, in which an experimental participant is asked to determine if a string of letters is a word or not, responses to items in a MIXed caSE format are slower than to items in PURE UPPERCASE or pure lowercase formats. In this experiment, we investigated the effect of different mixed-case formats on lexical decision performance, focusing on the type and location of the case transition. Twenty-four students participated in a lexical decision making experiment, consisting of twelve blocks of sixty-four six-letter items. Each block contained an equal number of words and pseudowords (nonwords that conform to rules of English orthography) presented in eight different case formats (e.g., travel, TRAVEL, Travel, tRAVEL, traveL, TRAVEl, traVEL and TRAvel). We found that mean response times to Initial Uppercase, PURE UPPERCASE and pure lowercase formats were all faster than the mean response times to all other MIXEd casE formats, suggesting that perception of initial uppercase items—a standard orthographic form in English—is different from that of other mixed-case formats.
Michael Iannicca, Dawei Du, and Dan Simon
Our research focuses on vision-based route planning for the NAO humanoid robot. The robot is required to visually observe a scene and decide the shortest possible route for visiting the points of interest in that scene. A robust method for processing image information is used to determine the locations to be visited. We use a perspective projection algorithm to map points from a camera image to locations in three-dimensional space. A camera calibration algorithm finds the distance from the camera to the image plane. Linear regression is used to obtain the equations of camera calibration lines. Thresholds and binary masks are used to distinguish locations in the camera image. Connected component algorithms are used to label and group objects. We use brute force optimization to solve the path planning problem. A matrix containing distances between all pairs of objects is computed, and then a brute force search is used to find the shortest path between those objects. In case the number of objects is greater than about 10, brute force is not computationally feasible, and so artificial intelligence algorithms are used to find the shortest path.
Pranav Joshi, Akshata Datar, Alexander D. Roth, Pratap Lama, and Moo-Yeal Lee
High content imaging (HCI) is a multi-parametric assay using multiple fluorescent dyes that are relevant to specific cell functions. The HCI assays provide an insight into the mechanisms of toxic drug responses, thus enhancing predictability of drug toxicity. However, current HCI assays are performed on 2D cell monolayer cultures which are physiologically irrelevant, creating a new opportunity for better predictable 3D HCI assays. The goal of this research is to develop HCI assays on 3D cellular microarrays that can be implemented for various toxicity screening, leading to classification of drug toxicity via investigating profiles of cell injury. As a model system, Hep3B human liver cells were dispensed onto a micropillar chip with a microarray spotter, which were exposed to various concentrations of model drugs. The chip containing the cells was then stained with multiple fluorescent dyes and scanned with a chip scanner to measure different end points. Conclusively, HCI assays performed on the 3D cellular microarrays showed a capability to identify several mechanisms of toxic drug responses. The mechanisms including DNA and mitochondrial impairment, calcium homeostasis, and glutathione conjugation were successfully demonstrated on the micropillar/microwell chip platform. Computational algorithms along with additional assays will be developed for enhanced predictability.
Seol Casey Kim, Anthony Berdis, and Jung-Suk Choi
Approximately 4,000 children in the United States are diagnosed annually with a brain tumor. Brain cancers are the deadliest of all pediatric cancers as they have survival rates of less than 20%. Although surgery and radiation therapy are widely used to treat adult patients, chemotherapy is the primary therapeutic option for children. One important chemotherapeutic agent is temozolomide, an alkylating agent that causes cell death by damaging DNA. In this project, we tested the ability of a specific non-natural nucleoside developed in our lab, designated 5-NIdR, to increase the efficacy of temozolomide against brain cancer. Cell-based studies demonstrate that the combination of 5-NIdR and temozolomide kills more cells compared to treatment with either temozolomide or 5-NIdR used alone. Microscopy techniques demonstrate that the combination of 5-NIdR and temozolomide causes cell death via apoptosis rather than necrosis. Animal studies using xenograft (nude) mice were performed to evaluate the in vivo efficacy and safety of this drug combination against brain cancer. Preliminary results are provided which indicate that treatment with 5-NIdR does not inhibit the rate of tumor growth. In contrast, treatment with temozolomide reduces the rate of tumor growth but does not lead to the complete elimination of the tumor. Striking results are obtained using 5-NIdR and temozolomide together as this drug combination causes a significant reduction in tumor size. Finally, mice treated with the combination of 5-NIdR and temozolomide do not show overt signs of side effects such as weight loss, dehydration, or fatigue. Collectively, these studies provide pharmacological evidence for combining 5-NIdR and temozolomide as a new treatment strategy to effectively treat brain cancers.
Pratap Lama, Alexander D. Roth, Pranav Joshi, Akshata Datar, and Moo-Yeal Lee
A high-throughput cell printing technology has developed to simulate the liver tissue environment using a hydrogel-based chip platform that has potential to shift in vivo drug toxicity models towards in vitro tests. However, the hydrophobic nature of polystyrene chips is not promoting direct adhesion of hydrogels, which created a problem with spot attachment. The main goal of this research is to create a surface chemistry that helps to attach a peptide-based hydrogel, including PuraMatrix, to a polystyrenebased micropillar chip. Seven analogs of maleic anhydride co-polymers were used to coat the micropillar chip to create a functional surface. Then, six ionic solutions were tested for inducing gelation of PuraMatrix. Formation of bubbles and spot detachment on the chip platform was quantified. As a result, an optimum polymer, PMA-OD was selected for surface attachment based on its low bubble formation and high spot attachment. This polymer could easily coat the chip for better gel adhesion. In regards to the gelation of PuraMatrix, poly-L-lysine was the most favorable for spot attachment and cell viability on the chip platform. In future research, encapsulated human liver cells expressing drug metabolizing enzymes will be tested with different drugs to determine mechanisms of drug toxicity.
Dale Lewis, Seyed Amirhossein Hosseini, and Jacqueline Jenkins
A driving simulation experiment was conducted to examine the performance improvement of participants while conducting a lane keeping task and two lane changing tasks on a straight road. Forty-four participants, sixteen females and twenty-eight males, drove one of three driving conditions. The data was analyzed to test whether 1) practice is better than no practice; 2) practicing a less challenging but similar steering task is good practice for a more challenging steering task; and 3) practicing a more challenging but similar steering task is good practice for a less challenging steering task. The results indicate that practicing the more challenging lane changing task had a significant impact on the performance of the subsequent, less challenging but similar task.
Dale Lewis; Roger Young; Jeffrey Eder; and Andrew B, Slifkin
Studies using a variety of experimental tasks have established that when humans repeatedly produce an action, fluctuations in action output are highest at the lowest frequencies and fluctuation magnitude (power) systematically declines as frequency increases. Such time series structure is termed pink noise. However, the appearance of pink noise seems to be limited to tasks where action is executed in the absence of task-related feedback. A few studies have demonstrated that when action was executed in the presence of task-related feedback, power was evenly distributed across all spectral frequencies—i.e., white noise was revealed. Here, participants produced cyclical aiming movements under visual feedback conditions and we sought to determine whether variations of both the movement amplitude requirement (A) and the target width (W)—in the form of the index of difficulty [ID = log2(2A/W)]—would predict the structure of movement amplitude (MA) time series. There were five ID levels, and there was a small-, medium-, and large-scale version of each ID: The A and W values doubled with each increment in scale level. Given that increases in ID are known to induce increased reliance on the available visual feedback, we predicted an ID-induced shift in MA time series structure from pink to white noise, with no change in MA structure across scale levels.
Chris L. Liptak, W. Paul Segars, Ashraf G. Morgan, Frank F. Dong, and Xiang Li
Currently, portable x-ray examinations do not employ automatic exposure control (AEC). To aid in the design of a size-specific technique chart, acrylic slabs of various thicknesses are often used to estimate x-ray transmission factors for patients of various body thicknesses. This approach, while simple, does not account for patient anatomy, tissue heterogeneity, and the attenuation properties of the human body. To better account for these factors, in this work, we determined x-ray transmission factors using computational patient models that are anatomically realistic. A Monte Carlo program was developed to model a portable x-ray system. Detailed modeling was done of the x-ray spectrum, detector positioning, collimation, and source-to-detector distance. Simulations were performed using 18 computational patient models from the extended cardiac-torso (XCAT) family (9 males, 9 females; age range: 2-58 years; weight range: 12-117 kg). The ratio of air kerma at the detector with and without a patient model was calculated as the transmission factor. The transmission factor decreased exponentially with increasing patient thickness. For the range of patient thicknesses examined (12-28 cm), the transmission factor ranged from approximately 25% to 2.8% when the air kerma used in the calculation represented an average over the entire imaging field of view. The transmission factor ranged from approximately 25% to 5.2% when the air kerma used in the calculation represented the average signals from two discrete AEC cells. These exponential relationships can be used to optimize imaging techniques for patients of various body thicknesses to aid in the design of clinical technique charts.
Victoria McDonough and Shelley Rose
The motivation behind the Social Studies @ CSU summer blog series is to encourage discussion among teachers about connecting historical thinking and technology with the content of their Social Studies courses. Many teachers are unaware of how to integrate critical thinking skills into their Social Studies courses, leaving students unable to use those skills to guide their own academic careers. Using the current model of Ohio Social Studies content standards and research completed by Sam Wineburg and Daisy Martin as a framework, the Social Studies @ CSU summer blog series provides technological and lesson planning resources and methods for integrating technology and historical thinking with Social Studies content. The results were seventeen blog postings that provide online resources and ideas that help teachers connect the content of the current Social Studies standards with modern technologies. Also featured are games and interviews with students and teachers that give practical advice and strategies about employing unconventional teaching methods to increase student engagement in Social Studies courses. In conclusion, the discussion about connecting historical thinking and technology in the classroom is ongoing, but research and current technologies are helping teachers integrate historical and critical thinking methods into their content more and more each day.
Monitoring Micelle Formation in Mixtures of Linear and Foldon-capped Polypeptides with Light Scattering Spectroscopy
Janna Mino, John P. Gavin, Michael G. Price, Kiril Streletzky, and Nolan Holland
Elastin-like polypeptide (ELP) polymers are ideal for producing environmentally responsive micellar systems because they exhibit a transition from being water-soluble at low temperatures to phase-separated at high temperatures. For application development of drug delivery vehicles and biosensing nanoparticles, it is important to prepare spherical micelles of controlled diameter and shape. Since at a given salt concentration, the headgroup area for each foldon should be constant, the size of the micelles is expected to be proportional to the volume of the linear ELP available per foldon headgroup. Therefore, adding linear ELPs to a system of ELP-foldon should result in changes of the micelle volume. At higher salts the electrostatic repulsion between headgroups is shielded, reducing the effective size of foldon headgroups, increasing the packing factor of micelles which leads to formation of non-spherical micelles. The effects of addition of linear ELPs on size, shape, and molecular weight of micelles at different salt concentrations were studied by a combination of Depolarized Dynamic Light Scattering (DDLS) and Static Light Scattering (SLS) Spectroscopies. The initial results on 50 μM ELPfoldon samples (at 25 mM salt) show that the apparent hydrodynamic radius of mixed micelles increases more than 5-fold as the amount of linear ELP raised from 0 to 50 μM. The size increase is accompanied by significant increase in depolarized scattering indicating the growing geometrical anisotropy of the micelles with increase of added linear ELP. In addition, the increase of the amount of linear ELP in the mixed micelles significantly increased the relative molecular weight of the micelles.