Electrospinsters Final Project Report

An electrospinning machine (EM) produces fibers and particles by means of applying a voltage process (electrohydrodynamic phenomena) to a polymer solution by incorporating the use of a receptacle, a pump, a high voltage power supply (HVPS) and a collector. EMs are typically very expensive, however, there has been work conducted by various researchers to construct in-house machines at a much lower cost. The growing applications for electrospinning continue to be a source of interest for many researchers as it is still a relatively new process. Much of the effort has been dedicated to producing nanofibers with unique properties with a focus on improving the efficiency and scalability of the process. The Electrospinsters Senior Design Team are researching and designing an in-house EM that can produce nanofibers for the team sponsor’s research and serve other educational purposes at Trinity University. The sponsor, Dr. Dany Munoz-Pinto, intends to use the results of this project to expand his research projects and goals by incorporating nanofibers into tissue scaffolds. The prototype must be a functioning EM so that a future team or the sponsor’s research students can make additions, but not struggle with the basic functions to create nanofibers. Based on published literature and additional research conducted by the team, we determined that an EM is composed of four subsystems: a syringe pump, a HVPS, a collector, and a user interface. The HVPS provides a voltage to the solution in the syringe pump which when exuded is drawn to the grounded collector due to the difference in electric potential. This drawn-out solution conglomerates on the collector which forms the scaffold. Published literature allowed us to gain a better understanding of the setup and we learned that there is not much variation in how the EM can be modified. Consequently, we chose to follow a fundamental setup with a flat collector plate due to its easy construction and compatibility with producing non-woven nanofibers with polyvinyl alcohol (PVA). We designed and conducted a series of tests to validate the subsystems of the device and to test the EM against various design constraints and project requirements. Some of our constraints pertained to time and budget and our project met both of these, as we successfully created a working prototype for our sponsor by the end of the 2023 spring semester, and we only used $808.92 of our$1200 budget. Other criteria related to health and safety were met, since we complied with TU Environmental Health and Safety and OSHA standards, the voltage applied to the solution did not exceed 30 kV at any point during testing and application, and our device fit dimensional constraints and was only operated in a CSI fume hood to prevent the inhalation of nanoparticles. Our prototype operates all electrical subsystems using US standard outlets. Certain requirements correlated with certain subsystems which had specific tests designed to evaluate the flow rate, voltage, voltage display, and nanofiber diameter. The Flow Rate Variability Test evaluated the syringe pump subsystem with variable flow rates of 0.5 mL/hr, 1.0 mL/hr, and 1.5 mL/hr and deemed accurate enough for testing purposes. The Voltage Variability Test tested the active voltage of the HVPS and verified its operation is within a ±5% margin of error. The Proof-of-Concept Test verified that the EM could produce non-woven nanofibers of 200 nm and that it is within ±20% error of previously published experiments, which are acceptable results for our sponsor’s research purposes. Additionally, we tested Tip Diameter Variability and Collection Distance Variability to observe the effects on the nanofiber diameter and determined that there is not a significant difference as they are still within ±20% error, as we had expected from published literature. Overall, the Electrospinsters created a successful, working prototype to aid in our sponsor’s research. Our prototype met all requirements and constraints, and there are no remaining changes needed to achieve our final goals. However, for further improvements, we hope that a future team will improve this final prototype by integrating another type of collector that can produce aligned nanofibers while maintaining the ability to interchange collector types and implementing any other useful additions or modifications

Preliminary investigation of flexibility in learning color-reward associations in gibbons (<i>Hylobatidae</i>)

Previous studies in learning set formation have shown that most animal species can learn to learn with subsequent novel presentations being solved in fewer presentations than when they first encounter a task. Gibbons (Hylobatidae) have generally struggled with these tasks and do not show the learning to learn pattern found in other species. This is surprising given their phylogenetic position and level of cortical development. However, there have been conflicting results with some studies demonstrating higher level learning abilities in these small apes. This study attempts to clarify whether gibbons can in fact use knowledge gained during one learning task to facilitate performance on a similar, but novel problem that would be a precursor to development of a learning set. We tested 16 captive gibbons' ability to associate color cues with provisioned food items in two experiments where they experienced a period of learning followed by experimental trials during which they could potentially use knowledge gained in their first learning experience to facilitate solution I subsequent novel tasks. Our results are similar to most previous studies in that there was no evidence of gibbons being able to use previously acquired knowledge to solve a novel task. However, once the learning association was made, the gibbons performed well above chance. We found no differences across color associations, indicating learning was not affected by the particular color / reward association. However, there were variations in learning performance with regard to genera. The hoolock (Hoolock leuconedys) and siamang (Symphalangus syndactylus) learned the fastest and the lar group (Hylobates sp.) learned the slowest. We caution these results could be due to the small sample size and because of the captive environment in which these gibbons were raised. However, it is likely that environmental variability in the native habitats of the subjects tested could facilitate the evolution of flexible learning in some genera. Further comparative study is necessary in order to incorporate realistic cognitive variables into foraging models

Migrant networks, language learning and tourism employment

This paper examines the relationship between migrants’ social networks, the processes of language acquisition and tourism employment. Data collected using netnography and interviews are used to identify the strategies that Polish workers in the UK use to develop their language skills. The paper highlights the roles played by co-workers, co-nationals and customers in migrants’ language learning, both in the physical spaces of work and the virtual spaces of internet forums. It also shows how migrant workers exchange knowledge about the use of English during different stages of their migration careers: prior to leaving their country of origin and getting a job, during their employment and after leaving their job. Implications for academic inquiry and human resource management practice are outlined

A Case Control Study of Nutrient Intake Deficiencies in Patients Taking Warfarin

Introduction We previously published the case of a woman taking warfarin who was found to have scurvy, a disease caused by a deficiency of vitamin C. This led us to hypothesize that patients taking warfarin who consume a diet limited in vitamin K rich foods may be at risk for other nutrient deficiencies. To test our hypothesis, we studied dietary nutrient intake in patients taking warfarin compared to patients with heart disease not taking warfarin. Methods The warfarin (n=59) and control groups (n=24) comprised convenience samples of patients with heart disease over age 60 years. Patients completed a three-day food diary and reported use of supplements. Results Based on diet history, the most common deficiencies were vitamin D (100% both groups), vitamin E (93% warfarin, 92% control), vitamin A (71% warfarin, 71% control), vitamin K (66% warfarin, 58% control), vitamin C (58 % warfarin, 46% control) and pantothenic acid (69% warfarin, 71% control) with no significant differences in intake deficiencies between warfarin and control groups. Conclusion All of our patients had nutritional intake deficiencies. This may be due to Appalachian dietary habits and not the low vitamin K diet. It seems prudent to recommend multivitamins, however, universal multivitamin supplementation has not been supported by randomized controlled trials. More study is needed to determine the reason for poor nutritional intake in our Appalachian population and to determine whether similar results are evident in a larger sample

Employment experiences of Polish migrant workers in the UK hospitality sector.

2010-2011 > Academic research: refereed > Publication in refereed journa

MLEA: a solution for users of android in UTP Virtual

This paper describes a design of an educational platform for a mobile learning architecture, which is a state of the art topic in distance education. The product will allow users to interact in an efficient, flexible, and transparent fashion with a web-based education environment, in this case Module Object-Oriented Dynamic Learning Environment (Moodle), using Android mobile devices. In order to provide a strong and lasting architecture, the Service Oriented Architecture (SOA) methodology is used given that it allows easy software re-utilization as well as integration of heterogeneous services. The architecture is based on web services implemented with Representational State Transfer (REST), as it has been demonstrated to be lighter and less consuming than other protocols, for devices with limited resources such as mobile devices. Web services provide the communication means between the server side and the client side of the architecture, whereas agents are used to deliver the services itself. The authors propose the development of an environment that facilitates the integration of various educational resources to support m-learning. An important aspect of the proposal is the offering of a tool to provide customized alerts for students and teachers, enabling them to remain updated about activities taking place in the coursesThis paper describes a design of an educational platform for a mobile learning architecture, which is a state of the art topic in distance education. The product will allow users to interact in an efficient, flexible, and transparent fashion with a web-based education environment, in this case Module Object-Oriented Dynamic Learning Environment (Moodle), using Android mobile devices. In order to provide a strong and lasting architecture, the Service Oriented Architecture (SOA) methodology is used given that it allows easy software re-utilization as well as integration of heterogeneous services. The architecture is based on web services implemented with Representational State Transfer (REST), as it has been demonstrated to be lighter and less consuming than other protocols, for devices with limited resources such as mobile devices. Web services provide the communication means between the server side and the client side of the architecture, whereas agents are used to deliver the services itself. The authors propose the development of an environment that facilitates the integration of various educational resources to support m-learning. An important aspect of the proposal is the offering of a tool to provide customized alerts for students and teachers, enabling them to remain updated about activities taking place in the course

I feel you: the design and evaluation of a domotic affect-sensitive spoken conversational agent

We describe the work on infusion of emotion into a limited-task autonomous spoken conversational agent situated in the domestic environment, using a need-inspired task-independent emotion model (NEMO). In order to demonstrate the generation of affect through the use of the model, we describe the work of integrating it with a natural-language mixed-initiative HiFi-control spoken conversational agent (SCA). NEMO and the host system communicate externally, removing the need for the Dialog Manager to be modified, as is done in most existing dialog systems, in order to be adaptive. The first part of the paper concerns the integration between NEMO and the host agent. The second part summarizes the work on automatic affect prediction, namely, frustration and contentment, from dialog features, a non-conventional source, in the attempt of moving towards a more user-centric approach. The final part reports the evaluation results obtained from a user study, in which both versions of the agent (non-adaptive and emotionally-adaptive) were compared. The results provide substantial evidences with respect to the benefits of adding emotion in a spoken conversational agent, especially in mitigating users' frustrations and, ultimately, improving their satisfaction

Identification and Characterization of Novel Compounds Blocking Shiga Toxin Expression in Escherichia coli O157:H7

Infections caused by Shiga toxin-producing E. coli strains constitute a health problem, as they are problematic to treat. Shiga toxin (Stx) production is a key virulence factor associated with the pathogenicity of enterohaemorrhagic E. coli (EHEC) and can result in the development of haemolytic uremic syndrome in infected patients. The genes encoding Stx are located on temperate lysogenic phages integrated into the bacterial chromosome and expression of the toxin is generally coupled to phage induction through the SOS response. We aimed to find new compounds capable of blocking expression of Stx type 2 (Stx2) as this subtype of Stx is more strongly associated with human disease. High-throughput screening of a small-molecule library identified a lead compound that reduced Stx2 expression in a dose-dependent manner. We show that the optimised compound interferes with the SOS response by directly affecting the activity and oligomerisation of RecA, thus limiting phage activation and Stx2 expression. Our work suggests that RecA is highly susceptible to inhibition and that targeting this protein is a viable approach to limiting production of Stx2 by EHEC. This type of approach has the potential to limit production and transfer of other phage induced and transduced determinants

Differential regulation of innate immune cytokine production through pharmacological activation of Nuclear Factor-Erythroid-2-Related Factor 2 (NRF2) in burn patient immune cells and monocytes

Burn patients suffer from immunological dysfunction for which there are currently no successful interventions. Similar to previous observations, we find that burn shock patients (≥15% Total Burn Surface Area (TBSA) injury) have elevated levels of the innate immune cytokines Interleukin-6 (IL-6) and Monocyte Chemoattractant Protein-1 (MCP-1)/CC-motif Chemokine Ligand 2(CCL2) early after hospital admission (0–48 Hours Post-hospital Admission (HPA). Functional immune assays with patient Peripheral Blood Mononuclear Cells (PBMCs) revealed that burn shock patients (≥15% TBSA) produced elevated levels of MCP-1/CCL2 after innate immune stimulation ex vivo relative to mild burn patients. Interestingly, treatment of patient PBMCs with the Nuclear Factor-Erythroid-2-Related Factor 2 (NRF2) agonist, CDDO-Me(bardoxolone methyl), reduced MCP-1 production but not IL-6 or Interleukin-10 (IL-10) secretion. In enriched monocytes from healthy donors, CDDO-Me(bardoxolone methyl) also reduced LPS-induced MCP1/CCL2 production but did not alter IL-6 or IL-10 secretion. Similar immunomodulatory effects were observed with Compound 7, which activates the NRF2 pathway through a different and non-covalent Mechanism Of Action (MOA). Hence, our findings with CDDO-Me(bardoxolone methyl) and Compound 7 are likely to reflect a generalizable aspect of NRF2 activation. These observed effects were not specific to LPS-induced immune responses, as NRF2 activation also reduced MCP-1/CCL2 production after stimulation with IL-6. Pharmacological NRF2 activation reduced Mcp-1/Ccl2 transcript accumulation without inhibiting either Il-6 or Il-10 transcript levels. Hence, we describe a novel aspect of NRF2 activation that may contribute to the beneficial effects of NRF2 agonists during disease. Our work also demonstrates that the NRF2 pathway is retained and can be modulated to regulate important immunomodulatory functions in burn patient immune cells