Matching Items (44)

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Increased interactions in active learning biology classrooms: Exploring the impact of instructors using student names and student academic self-concept

Description

Learning student names has been promoted as an inclusive classroom practice, but it is unknown whether students value having their names known by an instructor. We explored this question in

Learning student names has been promoted as an inclusive classroom practice, but it is unknown whether students value having their names known by an instructor. We explored this question in the context of a high-enrollment active-learning undergraduate biology course. Using surveys and semistructured interviews, we investigated whether students perceived that instructors know their names, the importance of instructors knowing their names, and how instructors learned their names. We found that, while only 20% of students perceived their names were known in previous high-enrollment biology classes, 78% of students perceived that an instructor of this course knew their names. However, instructors only knew 53% of names, indicating that instructors do not have to know student names in order for students to perceive that their names are known. Using grounded theory, we identified nine reasons why students feel that having their names known is important. When we asked students how they perceived instructors learned their names, the most common response was instructor use of name tents during in-class discussion. These findings suggest that students can benefit from perceiving that instructors know their names and name tents could be a relatively easy way for students to think that instructors know their names. Academic self-concept is one's perception of his or her ability in an academic domain compared to other students. As college biology classrooms transition from lecturing to active learning, students interact more with each other and are likely comparing themselves more to students in the class. Student characteristics, such as gender and race/ethnicity, can impact the level of academic self-concept, however this has been unexplored in the context of undergraduate biology. In this study, we explored whether student characteristics can affect academic self-concept in the context of a college physiology course. Using a survey, students self-reported how smart they perceived themselves in the context of physiology compared to the whole class and compared to the student they worked most closely with in class. Using logistic regression, we found that males and native English speakers had significantly higher academic self-concept compared to the whole class compared with females and non-native English speakers, respectively. We also found that males and non-transfer students had significantly higher academic self-concept compared to the student they worked most closely with in class compared with females and transfer students, respectively. Using grounded theory, we identified ten distinct factors that influenced how students determined whether they are more or less smart than their groupmate. Finally, we found that students were more likely to report participating less than their groupmate if they had a lower academic self-concept. These findings suggest that student characteristics can influence students' academic self-concept, which in turn may influence their participation in small group discussion.

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Created

Date Created
  • 2017-05

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Potential Anti-Biofilm Applications of Tolaasin

Description

As a major cause of nosocomial infections, biofilms such as those caused by Staphylococcus aureus and Staphylococcus epidermidis pose large concerns in the field of healthcare due to their extreme

As a major cause of nosocomial infections, biofilms such as those caused by Staphylococcus aureus and Staphylococcus epidermidis pose large concerns in the field of healthcare due to their extreme durability and resistance to treatment. While all biofilms grow similarly in a series of three stages: 1. Adhesion 2. Maturation 3. Dispersal, Staphylococcal species such as S. aureus and S. epidermidis make use of unique growth factors in order to form prolific and durable biofilms. Due to the prevalence and risks associated with bacteria, many antibacterial methods have been created to treat bacterial infections. Although many antibacterial methods exist, there is still a great need for additional and more effective methods to treat and prevent serious bacterial infections associated with biofilm growth, because incidences of bacterial infection and resistance, especially in medical settings, are on the rise. In recent research, the exotoxin tolaasin, produced by the bacterium Pseudomonas tolaasii has briefly been shown to exhibit antibacterial effects. Based on previous research and tolaasin's observed pore forming and detergent properties, it is hypothesized that tolaasin will disrupt and prevent staphylococcal biofilm growth either independently or synergistically with existing antibiotics. If this is confirmed, tolaasin may have major implications within the future of healthcare, particularly in the field of antibiotics. In order to optimally use tolaasin as an anti-biofilm agent, potential anti-biofilm applications would aim to prevent and treat biofilm infections at the most common sites of biofilm growth such as catheters, medical instruments, implanted medical devices, and surgical sites. In addition, under the assumption that tolaasin will be found effective in inhibiting biofilm growth and infection, this thesis proposes future anti-biofilm technologies that could use tolaasin as an anti-biofilm agent in order to prevent biofilms and associated infections. While there are many potential and promising ways that tolaasin could be used as an anti-biofilm agent in the future, there are still possible limitations that would need to be investigated through further research before these applications can come to fruition. Ultimately, if future research successfully determines that tolaasin can be used to make anti-biofilm technologies that are biocompatible, durable, and effective, then technologies using tolaasin as an anti-biofilm agent may more effectively ensure sterility of medical devices and prevent bacterial biofilms and infections, and may eventually save lives.

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Date Created
  • 2015-05

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Telomere Homeostasis Within Medaka (Oryzias Latipes)

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ABSTRACT Telomeres are vital in protecting chromosome ends to prevent telomere shortening. Telomerase is a ribonucleoprotein responsible for adding telomere repeats and maintaining telomere length. Telomerase holoenzyme consists of 2

ABSTRACT Telomeres are vital in protecting chromosome ends to prevent telomere shortening. Telomerase is a ribonucleoprotein responsible for adding telomere repeats and maintaining telomere length. Telomerase holoenzyme consists of 2 major subcomponents: telomerase reverse transcriptase (TERT) and telomerase RNA (TR). The catalytic subunit is TERT and the subunit that adds deoxyribonucleotide to the ends of chromosome is TR. TR contains an alignment portion and a template portion. Japanese Medaka (Oryzias latipes) has 4 nucleotide bases in its alignment region, which is similar to the 5-nucleotide bases in the human telomerase RNA alignment region. Because of the similar alignment region length, Japanese Medaka with 24 chromosomes was chosen to be used in this study. The question in this research was whether we could overcome heterogeneity. It was expected that when breeding short mean telomere length fish with another short mean telomere length fish, the new generation would have homogeneity. If short average telomere length fish and long average telomere length fish were to breed, the next generation fish would have heterogeneity in their average telomere length. In order to make a strong result statement further research needs to be done. The results from this study have somewhat supported the hypothesis, but will need additional information for a stronger validation. There were two inbreedings of short mean telomere length fish with another short telomere length; however, only one of the inbreeding pairs produced a fish with homogeneity (and supported the hypothesis). The other inbreeding pair depicted a large smear, a sign of heterogeneity. This may be due to a mutation in the subtelomeric portion. The method used to measure average telomere length was the terminal restriction fragment assay. Future research will involve using a different technique, quantitative fluorescence in sifu hybridizatrort to measure a more accurate telomere length of each chromosome.

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Date Created
  • 2012-05

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The effects of TWEAK-FN14 Signaling Axis in Esophageal Adenocarcinoma

Description

Esophageal adenocarcinoma is one of the largest growing cancer types in the United States and the whole world. One of the only known precursors to EAC is Barrett’s Esophagus, the

Esophageal adenocarcinoma is one of the largest growing cancer types in the United States and the whole world. One of the only known precursors to EAC is Barrett’s Esophagus, the changing of the normal squamous cells which line the esophagus into intestinal cells, following repeated exposure to gastric acids via gastroesophageal reflux disease. There is limited knowledge of the mutations and drivers that contribute to EAC’s low 5-year survival rates, demonstrating a need to identify new therapeutic targets. Given the development of EAC from chronic inflammation and acidic microenvironment, elevated expression of tumor necrosis factor receptor super family member 12A (TNFRSF12A, FN14) and its corresponding ligand, TWEAK, is correlated with disease progression. The functional role of the TWEAK/FN14 signaling axis is well documented in other cancer types, contributing to tumor invasion, migration, and survival. However, reports have shown the TWEAK/FN14 signaling axis can contribute “pro-cancer” and “anti-cancer” phenotypes in different tumor microenvironments. In this study, we seek to demonstrate the functional role of TWEAK and FN14 in EAC survival and migration. We hypothesized TWEAK/FN14 signaling would promoted EAC cell survival and migration. In this study, we illustrate increased expression of FN14 with disease progression. Following treatment with TWEAK, human EAC cell lines had increased sensitivity to standard chemotherapy treatment in vitro. Treatment with TWEAK also correlated with increased cellular migration, most likely in correlation with NF-κB activation. Finally, we showed that inhibition of FN14 via siRNA significantly reduced EAC survival and increased efficacy of standard of care treatments. This data suggests a diverse functional role of the TWEAK/FN14 signaling axis in EAC, and may be a potential target for novel therapeutics.

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Date Created
  • 2016-12

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STAT3 Inhibition as a Therapeutic Strategy in Esophageal Adenocarcinoma

Description

Esophageal adenocarcinoma (EAC) is the most prevalent type of esophageal malignancy in the United States (US) and the rate of occurrence continues to grow rapidly. As the prevalence of risk

Esophageal adenocarcinoma (EAC) is the most prevalent type of esophageal malignancy in the United States (US) and the rate of occurrence continues to grow rapidly. As the prevalence of risk factors such as obesity and gastroesophageal reflux disease (GERD) rises, the rates of EAC are expected to continue rising as well. Unfortunately, the 5-year survival rate remains low and the lack of targetable, oncogenic drivers presents challenges in developing more effective and less toxic therapeutics. The current standard of care for EAC involves combinations of chemotherapeutics and radiation therapy that can cause severe side effects and often leads to refractory and relapsed disease. According to the cancer stem cell model, a small subset of the tumor cell population is responsible for cancer's ability to replicate, metastasize, and relapse. These cancer stem cells (CSCs) can self-renew and differentiate. Napabucasin, a "stemness" inhibitor, which works by inhibiting STAT3, has shown promising results in pre-clinical and clinical investigations across a variety of solid tumor types. Because a major barrier in treatment of EAC is the likelihood of relapse, targeting the CSC population that results in this phenotype is a therapeutic strategy of great interest. We hypothesize that employment of napabucasin to inhibit stemness through STAT3 represents a viable therapeutic strategy in the EAC setting. In this study, we investigated the efficacy of napabucasin on EAC cells. Napabucasin was shown to reduce phosphorylation of STAT3 as well as levels of MCL1, a cell survival protein downstream of STAT3, and levels of "stemness" markers Nanog, Sox2, and B-catenin via immunoblot analysis. Napabucasin monotherapy showed high efficacy in some EAC settings, with IC50 values in a clinically achievable range. The treatment in combination with cisplatin, a standard of care chemotherapeutic, resulted in reduced cell viability than either treatment alone indicating that a combination strategy could reduce the dosage of each drug needed. The data suggests that STAT3 inhibition in combination with current standard of care treatments could be a viable therapeutic strategy in EAC, and improve the dismal survival for these patients.

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Agent

Created

Date Created
  • 2018-05

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Aerosolization Methods for Dispersion of Bacterial Cells in Air

Description

Legionella is a gram-negative bacterium with the ability for human infection by inhalation or aspiration of water containing the bacteria. Legionella live in aquatic environments and have been identified in

Legionella is a gram-negative bacterium with the ability for human infection by inhalation or aspiration of water containing the bacteria. Legionella live in aquatic environments and have been identified in cooling towers, humidifiers and respiratory therapy treatments, among others. Infection with Legionella bacteria leads to Legionnaire’s Disease or Pontiac Fever (Edelstein, 1993). Information regarding the means of aerosolization of Legionella bacteria has not yet been reported, therefore the relevance of experimentation was defined. The objective of this study is to determine the modes by which bacteria may be aerosolized under laboratory conditions. Specifically, to measure the amount of bacteria transported over a specific distance in a given amount of time and determine the most effective mode of bacterial aerosolization. Three methods of bacterial aerosolization were tested, these included an electric paint sprayer, an air paint sprayer and a hand-held spray bottle. E. coli was used as a surrogate for Legionella in experimentation due to its similar bacterial properties. Both bacteria are gram-negative, aerobic bacilli while Legionella is approximately 2 μm in length (Botzenhart, 1998), and E. coli is between 1 and 3 μm in length (Reshes, 2007). The accessibility and non-pathogenicity of E. coli also served as factors for the substitution.
In order to measure the aerosolization efficiency of each spray method, an air sampler was placed opposite to the position of the sprayer, on either side of a sealed box. Each sprayer was filled with E. coli concentrated at 104 CFU/ml in a PBS solution and sprayed for a time span of 1 and 5 seconds. For each of these time intervals an air sample was collected immediately following the spray as well as 5 minutes after the spray. Compared to the other two methods, the air spray method consistently showed the highest number of bacterial cells aerosolized. While all three methods resulted in the aerosolization of bacteria, the results determined the Air Spray method as the most efficient means of bacterial aerosolization. In this study, we provide a practical and efficient method of bacterial aerosolization for microbial dispersion in air. The suggested method can be used in future research for microbial dispersion and transmission studies.
In addition, a humidifier was filled with a spiked solution of E. coli and operated for a period of 1 and 5 seconds at its maximum output. Air samples were collected after 0 and 5 minutes. Immediately after the humidifier operation was stopped a small number of colonies were detected in the air sample and no colonies were detected in the air sample collected after a 5-minute elapsed time. This experiment served as a proof of concept for airborne pathogen’s transmission by a humidifier.

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Created

Date Created
  • 2015-12

Characterization of the structure and interactions of the AcrAB-TolC multi-drug efflux pump in Escherichia coli

Description

The spread of antibiotic resistant bacteria is currently a pressing global health concern, especially considering the prevalence of multi-drug resistance. Efflux pumps, bacterial machinery involved in various active transport functions,

The spread of antibiotic resistant bacteria is currently a pressing global health concern, especially considering the prevalence of multi-drug resistance. Efflux pumps, bacterial machinery involved in various active transport functions, are capable of removing a broad range of antibiotics from the periplasmic space and the outer leaflet of the inner membrane, frequently conferring multi-drug resistance. Many aspects of efflux machinery’s structure, functions, and inter-protein interactions are still not fully understood; further characterization of these components of efflux will provide a strong foundation for combating this resistance mechanism. In this project, I further characterize the channel protein TolC as a part of the AcrAB-TolC efflux pump complex in Escherichia coli by first determining the specificity of compensatory mutations in TolC against defective AcrA and AcrB, and then identifying TolC residues that might influence TolC aperture dynamics or stability when altered. Specificity of compensatory mutations was determined using an array of TolC mutants, previously generated from defective AcrA or AcrB, against a different mutant AcrB protein; these new mutant combinations were then analyzed by real-time efflux and antibiotic susceptibility assays. A vancomycin susceptible TolC mutant—a phenotype that has been associated with constitutively open TolC channels—was then used to generate vancomycin-resistant revertants which were evaluated with DNA sequencing, protein quantification by Western blots, and real-time efflux assays to identify residues important for TolC aperture dynamics and protein stability and complex activity. Mutations identified in revertant strains corresponded to residues located in the lower half of the periplasmic domain of TolC; generally, these revertants had poorer efflux than wild-type TolC in the mutant AcrB background, and all revertants had poorer efflux activity than the parental mutant strain.

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Date Created
  • 2016-05

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Student Conceptions of Collaboration within and between CUREs: An Investigative Analysis

Description

Course-Based Undergraduate Research Experiences, or CUREs have become an increasingly popular way to integrate research opportunities into the undergraduate biology curriculum. Unlike traditional cookbook labs which provide students with a

Course-Based Undergraduate Research Experiences, or CUREs have become an increasingly popular way to integrate research opportunities into the undergraduate biology curriculum. Unlike traditional cookbook labs which provide students with a set experimental design and known outcome, CUREs offer students the opportunity to participate in novel and interesting research that is of interest to the greater biology community. While CUREs have been championed as a way to provide more students with the opportunity to experience, it is unclear whether students benefit differently from participating in different CURE with different structural elements. In this study we focused in on one proposed element of a CURE, collaboration, to determine whether student's perception of this concept change over the course of a CURE and whether it differs among students enrolled in different CUREs. We analyzed pre and post open-ended surveys asking the question "Why might collaboration be important in science?" in two CUREs with different structures of collaboration. We also compared CURE student responses to the responses of senior honors thesis students who had been conducting authentic research. Five themes emerged in response to students' conceptions of collaboration. Comparing two CURE courses, we found that students' conceptions of collaboration were varied within each individual CURE, as well as what students were leaving with compared to the other CURE course. Looking at how student responses compared between 5 different themes, including "Different Perspectives", "Validate/Verify Results", "Compare Results", "Requires Different Expertise", and "Compare results", students appeared to be thinking about collaboration in distinct different ways by lack of continuity in the amount of students discussing each of these among the classes. In addition, we found that student responses in each of the CURE courses were not significantly different for any of the themes except "Different Expertise" compared to the graduating seniors. However, due to the small (n) that the graduating seniors group had, 22, compared to each of the CURE classes composing of 155 and 98 students, this comparison must be taken in a preliminary manner. Overall, students thought differently about collaboration between different CUREs. Still, a gap filling what it means to "collaborate", and whether the structures of CUREs are effective to portray collaboration are still necessary to fully elaborate on this paper's findings.

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Agent

Created

Date Created
  • 2016-05

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Evaluation of Collaborative Learning in a Blended Biology Course at ASU

Description

Collaborative learning has been found to enhance student learning experiences through interaction with peers and instructors in a way that typically does not occur in a traditional lecture course. However,

Collaborative learning has been found to enhance student learning experiences through interaction with peers and instructors in a way that typically does not occur in a traditional lecture course. However, more than half of all collaborative learning structures have failed to last very long after their initial introductions which makes understanding the factors of collaboration that make it successful very important. The purpose of this study was to evaluate collaborative learning in a blended learning course to gauge student perceptions and the factors of collaboration and student demographics that impact that perception. This was done by surveying a sample of students in BIO 282 about their experiences in the BIO 281 course they took previously which was a new introductory Biology course with a blended learning structure. It was found that students agree that collaboration is beneficial as it provides an opportunity to gain additional insight from peers and improve students' understanding of course content. Also, differences in student gender and first generation status have less of an effect on student perceptions of collaboration than differences in academic achievement (grade) bracket.

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Agent

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Date Created
  • 2014-05

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Using an Active Case Based Learning Model to Increase Scientific Interest, Understanding of and Confidence in the Process of Science in Secondary Education

Description

Many high school students demonstrate an overall lack of interest in science. Traditional teaching methodologies seem to be unsuccessful at engaging students \u2014 one explanation is that students often interpret

Many high school students demonstrate an overall lack of interest in science. Traditional teaching methodologies seem to be unsuccessful at engaging students \u2014 one explanation is that students often interpret what they learn in school as irrelevant to their personal lives. Active learning and case based learning methodologies seem to be more effective at promoting interest and understanding of scientific principles. The purpose of our research was to implement a lab with updated teaching methodologies that included an active learning and case based curriculum. The lab was implemented in two high school honors biology classes with the specific goals of: significantly increasing students' interest in science and its related fields; increasing students' self-efficacy in their ability to understand and interpret the traditional process of the scientific method; and increasing this traditional process of objectively understanding the scientific method. Our results indicated that interest in science and its related fields (p = .011), students' self-efficacy in understanding the scientific method (p = .000), and students' objective understanding of the scientific method (p = .000) statistically significantly increased after the lab was administered; however, our results may not be as meaningful as the p-values imply due to the scale of our assessment.

Contributors

Agent

Created

Date Created
  • 2012-12