Saja Abid and Rebecca Z. German
The superior laryngeal nerve (SLN) carries sensory information from the mucosal tissues of the pharynx superior to the vocal folds, and carries motor signals to the cricothyroid muscles. It also provides partial innervation to the thyroarytenoid and posterior cricoarytenoid muscles. Finally, the SLN initiates the swallow. When a food or liquid bolus is swallowed, the epiglottis and the false and true vocal folds work together to seal off the airway and allow the bolus to pass through the esophagus. If the SLN is damaged, it usually leads to dysphasia in which food or liquid enters the airway. We hypothesized that a lesion in the SLN would (1) cause an increase in liquid bolus entering the airway, and (2) the coordination between the soft palate, hyoid bone, thyroid cartilage, and epiglottis would be decreased. We surgically transected the right SLN in four 2- 3 week old infant pigs. Under anesthesia, radio-opaque markers were injected into the soft palate, or sutured into the tissues superficial to the hyoid bone and thyroid cartilage. A metal clip was placed onto the tip of the epiglottis to facilitate visualization. Videofluoroscopy was used to assess the airway protection. We digitized the markers to assess movement of the pharynx and larynx during swallows. We found that the unilateral lesion of the SLN did not significantly affect the airway safety. However, it appears that sensory deficits have a considerable impact on neuromuscular coordination. Without the sensory information, the brainstem sends poor, uncoordinated instructions to the muscles controlling the soft tissues of the pharynx.
Effect of parental communication on adjustment of typically developing children with an atypically developing sibling
Christina Adkins and Meghan Murray
Disorders comprised of intellectual and developmental disabilities (IDD) as a group are comprised of autism spectrum disorders, Down syndrome, and various genetic conditions that stunt the intellectual and functional development of an individual. These disorders affect roughly 14% of families in the US (Boyle et al., 2011), which approximates to seven million households in the US. The presence of IDD in a child is often associated with increased stress for the parents, given that IDD is often accompanied by behavioral problems in the affected child. Surprisingly, relatively little work has been done on the effects of IDD on typically developing children (TD) of the affected siblings. The few studies that examine these effects show mixed results, with some noting worse adjustment, in the form of greater internalizing problems (e.g., depression & anxiety) and externalizing behaviors (e.g., oppositional defiant behaviors) in the TD child that continues through adulthood, and others noting positive interpersonal outcomes (Kersh, 2007; Hodapp, Urbano, & Burke, 2010). One potential explanation for these mixed findings may lie with the communication between parents and their TD offspring. Specifically, discussing the IDD sibling's condition with the TD child may reduce the resentment these youths often feel by the high parental demands required by their IDD sibling. Further, it may reduce the TD child's worries about developing the IDD child's condition. This study aimed to examine the role of parental communication in the TD children's worries about their IDD sibling and their internalizing and externalizing symptoms.
Maryam Assar and Noopur Joshi
During meiosis, homologous chromosomes, one set maternal and the other set paternal, pair with one another. Pairing is a prerequisite for crossing over, where allelic regions on homologs break and recombine with the corresponding homolog. This crossing over results in recombinant chromosomes that in turn increase genetic diversity. What causes the homologs to pair at specific sites is unknown. We are investigating whether specific DNA sequences are involved in pairing. Our first step to identify pairing sites involves mitotic cells of budding yeast in order to isolate pairing regions in sister chromatids. Mitotic cells are used instead of meiotic cells since in haploid vegetative cells pairing can only occur between sister chromatids whereas pairing may occur between sister chromatids and/or homologs in meiotic cells. To isolate pairing regions, it is essential to capture the cells at a stage of the cell cycle when sister chromatids are present in the nucleus. The G2 phase of the cell cycle represents such conditions. Cell cultures were synchronized through initial starvation and then placement in rich growth media. In order to determine whether a sizable portion of the cells were in G2, the culture was analyzed at each time point using microscopy with a fluorescent dye that specifically interacts with DNA (DAPI). A systematic categorization based on cell morphology was used to determine the number of cells in G1, G2, S-phase and mitosis. We found that the optimal time for starving the cells in YPA medium was 17 hours. Following to rich YPD medium, growth for 2.5 hours gave the highest percent of G2 cells. In two vegetative cultures, 28% of cells were at G2 at this point. Given these results, we will be able to enrich for paired homologous sequences utilizing an appropriate molecular assay. Such isolation of paired DNA sequences will assist in decoding the foundations of genetic diversity.
Andrew Aylward and Kyra Ruby
Functional electrical stimulation (FES) is a method of restoring function to muscles using electrical pulses delivered through an implanted controller. FES has shown potential for enabling people with high spinal cord injuries to perform basic reaching motions essential to everyday tasks. In order to determine the necessary muscle activations an FES neuroprosthesis must produce to cause a desired arm motion, we must first be able to predict the amount of torque that muscles can produce at each joint. The torque production varies depending on the state of the system. Gaussian Process Regression models were trained with data gathered using a dynamic arm simulator in MATLAB that includes models of joint and muscle groups within the shoulder and arm. The Gaussian Process Regression models are able to predict, with acceptable accuracy, the torque at a given joint due to the activation of a certain muscle group. These predictions can be used to develop a method to calculate the muscle activations that will produce the torques necessary to move the arm along a specified trajectory.
Mudenda Martin Bbela
Using the Microsoft Kinect® in conjunction with an Android Wear device, this project aims to design a Privacy Aware 3D motion tracking application with haptic feedback functionality used to reduce prevalence of Back Injuries in Caregivers. The System will use a registration method to ensure the caregiver is both uniquely tracked and abstract from most of the information used by the application.
Effect of Salt Concentration on the Composition of Elastin-Like Polypeptides in the Condensed Coacervate Phase
Louise L. Beckstrom, Adam Maraschy, and Daniel P. Miller
Elastin-Like Polypeptides (ELPs) are thermo-responsive polymers which could potentially be used as vehicles for drug delivery. The nanoparticle vehicles are called micelles and the basic structure is made of ELP-foldon. This ELP-foldon has a head group (foldon) that is hydrophilic and three tails (ELP) that are hydrophobic. Above a certain temperature, the transition temperature (Tt), the hydrophobic tails aggregate together to form spheres with the hydrophilic headgroups on the outside. Inside the micelles, linear ELP and drugs can be captured. Although micelles can form without linear ELP, they are bigger when it is present. At lower temperatures the ELPs are fully soluble and exist as one solution phase, but at higher temperatures there exists two liquid phases. Even though they are both liquids, one is more viscous than the other. The less viscous phase is mostly water and the more viscous one is a condensed phase called a coacervate. Coacervate consists of a high concentration of protein, but still contains a significant amount of water. It appears as glue-like substance with a slight yellow tinge. The concentration of linear ELP may depend on the concentration of salt in solution and since the body naturally contains salt, knowing this relationship would be useful in designing micelles for drug delivery. We varied the concentration of salt in linear ELP to see its effect on the volume of the condensed coacervate at different temperatures.
Effect of p38 kinase and cell cycle position on the expression of the pro-apoptotic Bcl2 family member PUMA in skeletal myoblasts
Victoria Bensimon and Briana Boslett
Skeletal muscle regeneration relies on myoblast stem cell differentiation and is a crucial response to muscle injury caused by trauma and numerous diseases. In skeletal myoblasts, cell death and differentiation are mutually exclusive biological endpoints that are both induced by culture in differentiation media. MyoD, the master muscle- specific transcription factor, is well-known to regulate the expression of muscle specific genes such as myogenin and the ensuing differentiation. However, we have previously reported that MyoD also plays a critical role in the expression of PUMA and apoptosis, rather than myogenin and differentiation, in a subset of myoblasts, thus diminishing the regeneration. It is, therefore, critical to understand the molecular events that distinguish between this coordinate regulation of differentiation and apoptosis by MyoD. p38 kinase is known to be required for the expression of myogenin. Herein, we report that pharmacological inhibition of p38, while diminishing the expression of myogenin, actually enhances the expression of PUMA. Since myoblast cell cultures are asynchronous, we hypothesized that cell cycle position may contribute to this molecular distinction. To investigate this possibility, we have successfully synchronized cultures and experiments are underway to determine the effect of cell cycle position on PUMA expression versus differentiation specific gene expression.
Lrenzo Bianco, John DeMarco, and Sarah Gualtier
Introduction Injurious falls have risen significantly in the past decade, raising concerns about the efficacy of fall prevention programs. The purpose of this study was to analyze the correlation between perceived and observed balance measures used in a falls prevention program. Methods Subjects (S) were 70 (F), 59 (F), and 73(M). They were taught the Rate of Perceived Stability (RPS), a perceived measure of balance intensity and completed the Berg Balance Test (Berg), Timed up and Go (TUG), and Activities Specific Balance Confidence Scale (ABC). The Berg and TUG are observed measures and the ABC is a perceived measure. Last, subjects underwent Limits of Stability Testing (LOS), an observed measure allowing calculation of base of support (BOS) and center of mass (COM). Results The Berg predicted fall risk for S2 and 3 (2:51/56, 3:43/56). TUG results were well below age norms for S 1 and 3 (1: 12.1s, 3: 12.7s). S1 and 3 reported fear of falling; S 2 and 3 reported frequent falls. LOS testing showed S1 and 3 with minimal COM movement. Discussion S1, with a fear of falling, history of falls, and no fall risk, moved slowly and with minimal COM displacement. S2, with a fall risk and history of falls, moved with more COM excursion. S3, with a fall risk and history of falls, moved slowly with little COM excursion. Perceived versus observed clinical balance measures correlated well. LOS analysis was more complex, however, perceived RPS scores mirrored observed measures. This study provides initial feasibility data on this assessment protocol. Conclusion Perceived balance scores matched actual balance measures when overall excursion and movement speed were taken into account in this preliminary descriptive study.
Novel prosthetic devices must undergo testing as part of their development. Testing with amputees is problematic at the development stage due to safety and administrative burdens. A bent-knee adaptor allows able-bodied individuals to wear a prosthesis and facilitate prototype testing. An existing bent-knee adaptor was used as a basis to design an improved device. The existing adaptor did not preserve alignment between thigh and prosthesis, resulting in unnatural walking. 3D scanning and printing technologies were used to design the new adaptor. Solid modeling was used to verify that the new design would withstand the loads associated with walking. The device was 3D-printed and attached to a prosthesis, and a preliminary walking test was conducted. Improvements will be required in terms of a better fit between the user's thigh and the adaptor. A systematic procedure will be followed to tune the prosthesis control system. For this, the subject will wear a safety harness and walk over a treadmill. The user will undergo a natural learning process to improve walking.
Abdo Boumitri and Shuai Zhao
Ischemic injury in skeletal muscle caused by hypoxic (low oxygen) conditions occurs in response to vascular and musculoskeletal traumas, diseases and following reconstructive surgeries. Thus, a thorough understanding of the effect of hypoxia on skeletal myoblasts is warranted to identify potential therapeutic targets. We have determined that treatment with cobalt chloride (to mimic hypoxic conditions) leads to decreased numbers of viable (attached) skeletal myoblast over time and an increase in the percentage of detached myoblasts. To determine the contribution of apoptosis (cell death) to this increase in detached myoblasts, we assessed PARP cleavage, a well- accepted marker for apoptosis. Consistent with cell death via the apoptotic process, PARP cleavage was detected following cobalt chloride treatment. We next assessed the effect of cobalt chloride on the expression of the pro-apoptotic Bcl2 family member PUMA. We determined that after three hours, cobalt chloride treated myoblasts possessed PUMA mRNA levels six times greater than untreated myoblasts. Further, this increase in PUMA mRNA resulted in a three-fold increase in PUMA protein. Future experiments will focus on determining the mechanism whereby cobalt chloride treatment results in increased PUMA levels.
Mark Bowling and William Myers
Organic molecules offer a potentially cheap and environmentally friendly alternative to traditional silicon based electronics. The main limitation is that they are not as conductive as their inorganic counter parts. By crystalizing organic molecules, it is possible to increase the conductivity so that they can be more competitive with silicon electronics. This project examines the crystallization of polymers through selfassembly on the Au(111) surface reconstruction. The success of the crystallization is characterized with scanning tunneling microscopy (STM). In order to achieve high resolution STM images, we examined acoustic isolation by enclosing the microscope within a rubber-coated box, which was not effective, and a cylindrical shell lined with open cell foam. This was determined by examining both the images and the tunneling current data both with and without the acoustic isolation. We were further able to demonstrate that acoustic noise, while it destroys the ability to take high resolution images, does not appear in the tunneling current, which has not been previously reported. Finally, we report on the ability to create flat terraces of the Au(111) surface.
Cloud albedo, or the proportion of sunlight reflected by a cloud, has a significant impact on the Earth's radiation budget and is strongly influenced by cloud shape. It is a major source of uncertainty in climate modeling. To characterize the shape of shallow cumulus clouds we study the behavior of the cloud overlap ratio, the ratio between the average cloud fraction and projected cloud cover. In this study, we use a high resolution computer model (LES) to 1) determine how the cloud overlap ratio of a cloud field is related to the overlap of individual clouds, and 2) to study how the cloud overlap behaves under different atmospheric circumstances. We find that the overlap ratio does not vary much between different cases or cloud heights, but it is sensitive to cloud layer depth and that the smallest clouds in a field contribute a negligible amount to the albedo.
People who have suffered high spinal cord injuries are unable to move their limbs. Functional electrical stimulation (FES) activates paralyzed muscles by electrical current and is a way to restore some function to a paralyzed arm. This research was conducted to develop a way for a caregiver to correct reaching movements to a person with paralyzed arms. We asked participants to take part in this study to help obtain data to test the learning feedback system. We represented a paralyzed arm with a Barrett Medical Proficio robot. The robot is programmed to reach out and purposely miss a target. The participant then moves the robot arm during a second reach to correct the reaching movement in order to hit the intended target. While moving the robot's arm, we record the forces required to move the arm to reach its intended target. With the data collected by the force sensor, we were able to calculate new joint torques from the applied forces and program the robot arm to move to the correct position using those joint torques. These results show promise for developing an adaptive feedback system to correct reaching movements for use with FES systems for people with paralyzed arms.
Subjects who participate in driving simulation experiments often experience symptoms similar to motion sickness, called “simulator sickness.” However, the exact cause of these symptoms is unknown, which makes it difficult to predict whether a subject will experience them, or to warn them of the likelihood of experiencing those symptoms. A possible relationship between motion sickness and simulator sickness has been conjectured, based on the similarity of the symptoms, but not proven. In this study, we examined whether subjects in CSU simulator experiments who reported a history of motion sickness were more likely to experience the symptoms of simulator sickness. We performed a meta-study of 6 CSU driving simulation experiments and compared subjects' reports of past experiences with motion sickness to their symptoms of simulator sickness before and after the tests. We found that the subjects who reported having experienced motion sickness in the past were more likely to experience an increase in simulator sickness symptoms during the test, and to report these symptoms to a greater degree after it was over, particularly if they reported having experienced motion sickness while being a passenger in a car or small boat, or while riding a bus. This knowledge will allow researchers to more accurately predict whether a subject is likely to experience simulator sickness during this type of experiment, and to forewarn subjects about their personal risk of experiencing those symptoms.
Sophia DeGeorgia, Katharine Komisarz, Ashka Patel, and Raghavendra Yadavalli
Malaria is a potentially fatal disease caused by parasites in the genus Plasmodium. Of the five species that cause human malaria, P. falciparum causes an estimated 1 million deaths annually, particularly in young children in sub-Saharan Africa. Plasmodium falciparum is most commonly found in tropical and subtropical regions of the world. After invasion into human red blood cells, parasite induced transport structures known as Maurer's clefts, are formed within red cells. In previous studies, two Maurer's clefts proteins were identified; an approximately 130 kDa peripheral membrane protein and a 20-kDa integral membrane protein. Immunofluorescence and confocal microscopy identified both proteins within large cytoplasmic vesicles in the red cell cytoplasm. The 20 kDa protein, known as P. falciparum Maurer's cleft two transmembrane protein (PfMC2TM), is encoded by a family of genes identified using proteomic analysis of immune complexes (IC). The gene encoding the 130 kDa protein is unknown. Furthermore, the mechanism of protein trafficking after protein expression is also unknown. Our goal in this study was to prepare IC using schizont extracts for use in proteomic analysis to identify the gene encoding the 130 kDa protein, identify the pathway of protein traffic using Brefeldin A (BFA) in P. falciparum cultures and perform bioinformatics analysis of the PfMC2TM gene family using the database, PlasmoDB (plasmodb.org). The 110 kDa Rhop-3 rhoptry protein and PfMC2TM were identified using immunoprecipitation and western blotting analysis of parasite extracts prepared with Triton X-100 in stage specific and BFA treated parasites. PfMC2TM proteins encoded by family members in P. falciparum strains 3D7 and IT were compared to one another and across species in P. reichenowi. Among the proteins encoded by paralogs in P. falciparum, there were some differences found. However, there was no reported expression data annotated for P. reichenowi within PlasmoDB. Increasing knowledge of the Maurer's clefts proteins is crucial in understanding P. falciparum biology and the role of the clefts in malaria vaccine development.
To further understanding of light scattering on solution of anisotropic hard-to-image soft particles such as elastin-like polypeptide micelles the light scattering characterization of anisotropic easy-to-image inorganic gold nanoparticles was undertaken. We used Depolarized Dynamic Light Scattering (DDLS) and Scanning Electron Microscopy (SEM) to study commercial gold nanoparticles: nanospheres, nanorods with aspect-ratio=3, and nanorods with aspect ratio=7. According to SEM particles appeared to be larger than manufacturer specs, namely 2R=18.9±1.3nm, (26.1±4.1)x(65.5±9.5)nm, and (16.3±2.2)x(103.6±16.7)nm, respectively. DDLS on nanospheres showed no rotational diffusion (VH) signal, q dependence of decay rate consistent with that of spherical particles, no concentration dependence of translational diffusion coef- ficient (DVV), no absorption change under incident laser light, and a hydrodynamic radius Rh=12.2±0.4nm, largely consistent with SEM-measured size. The aspect-ratio=3 rods also revealed no VH signal, sphere- like q-dependence of decay rate, no concentration dependence of DVV, and apparent Rh=20.9±0.5nm. These samples also revealed unexpected change of absorption and color under incident laser light. However, the absorption change didn't affect particle diffusion. In other words, DDLS on 26x66nm nanorods yielded apparent diffusion properties of 41.8nm diameter spherical particles! DDLS on aspect-ratio=7 rods revealed noticeable VH signal and significant change in absorption altering diffusion properties under the laser light. The absorption change might have been caused by plasmon resonance, which greatly alters the particles' absorption. It was also found that, after certain “exposure” to the laser beam 16x104nm particles became stable and showed diffusion properties consistent with diffusion of cylinders.
Variation of bone microarchitecture within and among contemporaneous species of fossil horses: Feasibility
Emily A. Edwards
Mesohippus, Miohippus, and Merychippus are extinct horse species that date back fifteen to thirty million years ago, which spanned over three time periods in North America. Each of the horses habituated different terrains from wet to dry. The third metacarpal became the prominent one-toe of horse evolution and is the specimen of this study. The aim is to determine if reorientation, segmentation, correcting size differences, and isolation are feasible. Horse fossils are extensive, documented, and are used as an analogous fossil lineage to humans for this study. Imaging of the third metacarpal was accomplished by micro-CT scanning with a focus on the distal end. Each specimen was standardized using methodical steps to show feasibility. Reorientation was used to align the same bone landmarks of each fossil. Segmentation was performed and separated bone from non-bone. Fossils were corrected for size differences for relative comparison. Isolating bone was accomplished by using arithmetic for the distal end. Evolution of the equine foot is important for equine health, sports, foot paleontology, and can analogously be converted to human orthopedics. As a feasible study for future bone microarchitecture, this analysis serves to present an enhanced understanding of standardizing the third metacarpal of horse fossil bones.
Biostatistical Analysis on the Effects of the Circadian Clock & Glucose Genes on Different Feeding Regimens
Rana Faraj and Nikkhil Velingkaar
Circadian clocks are internal biological systems that control many physiological processes. The circadian clock is considered to be the master regulator of metabolism in mammals. The molecular metabolism is not very well known. The circadian clock regulated expression in metabolic enzymes and in turn, diet also regulates circadian clock on a molecular level. To better understand the interaction between circadian clock and metabolism, mice were subjected to different feeding regimens and metabolic tissue, such as liver and skeletal muscles, have been collected across the circadian cycle. Expression of genes have been analyzed in the liver using RT-QPCR. Large set of experimental data on the expression of circadian clock genes and metabolic genes in the liver of mice on different feeding regimens across the circadian cycle has been collected. My task is to analyze using the statistical analysis which treatment has statistically significant effect on rhythms of gene expression. First, I will have to work with three softwares on some data that has been previously analyzed in order to understand how it works and find out the most appropriate one to use. Once that has been done, I will select the software and use future data in this particular software. The complexity of this task is complicated because it comes from multiple parameters, such as several diets and time of day, which might have effect on gene expression.
Glycerolipid Analysis of Adaptation to Saline Changes in the Culture Conditions of Algae, Scenedesmus dimorphus, by GC-MS
Tyler Fitzgerald, Satya Girish Chandra Avula, and Chandana Mannem
Since fossil fuels are decreasing over time an alternative energy source will be soon required. The algae, Scenedesmus dimorphus, grows in freshwater and is known for its fast growth of glycerolipid content which is used for biodiesel production. After the algae is grown in optimal conditions, the released fatty acids and glycerolipids are transformed into fatty acid methyl esters (FAMEs) which are used as biodiesel. The FAMEs were quantitatively determined by gas chromatography mass spectrometry (GC-MS) to determine the total glycerolipid content in the different algae samples. The samples that were analyzed include freshwater controls and saline adapted samples. Analysis also included using a calibration curve with calibrators ranging from 0.500 to 1,000 μM. In the calibration curve and algae samples, a heavy isotope internal standard of C16:0-d-2 was used to determine the accuracy of the results. Results: total percent glycerolipid content in each sample ranged from 2.95-8.5%. The lower range of results could be due to the control 2-L bottle which had no CO2since it did not have optimal growth conditions, and the bioreactor control was low possibly due to low light intensity. However, the 1.005 TSG for the 2-L bottle was similar to the controls which proves that adaptation is successful. Also, the bioreactor control was lower than the 1.005 TSG saline sample in the bioreactor which shows that increasing the salt concentration and controlling the environment is useful for saline adaptation.
"Say it in Polish!": The Role of Heritage Language in preserving culture among families of Eastern European Origin
Beth Friedman-Romell, Taylor Darfus, and WanCheng Tsai
This project is part of a larger qualitative research study exploring the relationship between Eastern European American parenting styles and children's academic achievement. Seven mothers who were either first- or second-generation Eastern European American participated in semi-structured individual interviews. This project focuses on heritage language preservation. It revealed motivations, strategies, and outcomes of parents' desire to transmit their heritage language to the next generation. All participants had at least one child between ages five and eighteen. Based on our findings, four themes have emerged: 1) Motivations for heritage language preservation; 2) Resources and strategies to foster heritage language learning; 3) Family factors affecting heritage language transmission and fluency; and 4) Children's evolving attitudes to heritage language.
Amanda Gedeon and Christopher Morris
The goal of Protest Voices was to create classroom resources using oral history interviews for use in social studies classrooms. Oral histories remain underutilized as primary sources. In an effort to engage students with the historical thinking process, we created clips from oral history interviews of Cleveland-area peace activists and connected those clips to the Ohio Department of Education Social Studies standards. Our work focused on collecting interviews from individuals who were involved in antiVietnam protests and members of the Cleveland Latin American Mission team to El Salvador, as well as the InterReligious Task Force. The project created a collection of twelve oral history interviews and numerous clips for classroom use. According to the Oral History Association, oral history interviews “foster intergenerational appreciation and an awareness of the intersection between personal lives and larger historical currents.”1 Our aim was to connect educators, and thus students, with the voices of those who witnessed historical events in order to bring history alive and facilitate the historical thinking process. All of the interviews conducted are archived in the Cleveland Regional Oral History Collection and clips are part of the History Speaks blog.
Nicholas Gehler and Philip Sesco
To replace a human during experiments, we've calculated the endpoint stiffness of a human arm to be simulated on a robot. The model used to calculate arm stiffness includes gravitational, short-range muscle, and muscle force-moment arm stiffnesses. The parameters of this model were estimated using data from the open source musculoskeletal MATLAB model, Dynamic Arm Simulator. The model will be used by a Barrett Proficio robot to simulate the stiffness of a human arm. The purpose of this human arm simulation is for experimentation during the development of a force sensing feedback system for functional electrical stimulation (FES). A robot that moves and produces similar stiffness to a human arm will be used in place of a human during experiments, for reproducibility and convenience. This requires the stiffness an arm produces under FES control to be computed and then replicated on the robot. Having an accurate representation of the stiffness an arm produces will create a better lab environment for the promotion of FES research.
STEM (Science Technology Engineering and Mathematics) focused high schools have previously shown promising outcomes in the urban districts, where low income students have lower graduation rates, college acceptance and less access to advanced fields of study as compared to students of wealthier school districts. Modeling a protein design course from a private school, we aim to develop curriculum for a biotechnology course for an urban high school. Biotech is an emerging multidisciplinary field that could have similar outcomes to STEM education. We also aim to measure outcomes including student perspective of resulting STEM and career choice, using ethnographic methods.
Donald Grimes, Maggie Kolovich, Justin Flaherty, Umesh Balar, and Hitarthsinh Chudasama
Aerospike nozzles possess many qualities that make them more desirable and efficient than conventional bell-shaped rocket nozzles. Aerospike nozzles have been studied since the 1960s, but problems and limitations with experimentation often led to abandoning further efforts on aerospike nozzles and implementing much more familiar bell-shaped nozzles. In fact, aerospike nozzles have yet to be used in flight—they have only undergone ground testing. The goal of our research is to develop multiple additively manufactured aerospike nozzles and characterize the flow experimentally, numerically, and computationally. Schlieren photography and Particle Image Velocimetry (PIV) are used to experimentally characterize the flow, ANSYS CFD software and SolidWorks Flow Simulation are used to computationally analyze the nozzle flows, and hand calculations with the assistance of Matlab and Microsoft Excel are performed to analyze the nozzle flows numerically. Using these methods, we will study and compare the flows present in aerospike nozzles with a singular annular entrance as well as multiple orifice entries. To date, we have developed an experimental setup and procedure to study the nozzles we produce. Furthermore, using this setup we've successfully designed, manufactured, and analyzed a converging-diverging nozzle for our setup that produces supersonic flow—a necessary property of flow to accurately characterize nozzles use for aerospace applications. We hope that our research helps to develop a better understanding of aerospike nozzles and their many advantages over the bell nozzle, and motivates further research and eventually the implementation of aerospike nozzles in both aircraft and spacecraft.
Correlating Wet-sample Electron Microscopy with Light Scattering Spectroscopy on the Example of Polymeric Microgels
Amphiphilic cellulose-based microgels with a reversible volume-phase transition at around 40.5°C—the low critical solution temperature (LCST)—have been synthesized, characterized, and optimized. After carefully planned synthesis and filtering the samples with a 0.22μm filter microgels were characterized with dynamic light scattering (DLS), yielding reproducible results for the radii of particles around 100-120 nm below the LCST and 60-70 nm above it. Through the use of scanning electron microscopy (SEM), air dried samples and wet samples were also analyzed. Air dried samples were dried for 24 hours until all water was evaporated, ensuring the collapse of microgels as if they were expelling water above the transition. It was discovered that air dried microgels at room temperature had radii of 60-70 nm identical to radii determined from DLS above the LCST. Wet samples were imaged in home- made wet cells that contained in a silicon nitride window and sealed with epoxy glue to examine microgels in natural state of droplets in solution. The wet samples at room temperature revealed microgel radii larger than radii observed via DLS, indicating a need to look further into the SEM wet sample method both below and above the transition.
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