Digital Commons Network^™

Multicourse Comparative Study Of The Core Aspects For Flipped Learning: Investigating In-Class Structure And Student Use Of Video Resources, Nicole Naibert, Emryse Geye, Michael M. Phillips, Jack Barbera

Chemistry Faculty Publications and Presentations

Since 2013, the number of publications on flipped learning within chemistry have steadily increased. However, most of these studies focus on flipped course reforms within individual institutions, while the outcomes of any learning environment are dependent on how the environment is structured and the degree to which students interact with its elements. In this study, we apply a coordinated set of assessment practices to investigate similarities among flipped chemistry courses at five institutions in the United States. All courses in the study followed the two basic tenets of flipped learning: (1) foundational information was delivered through preclass materials (PCMs), and …

Phosphorylation Of Adp-Glucose Pyrophosphorylase During Wheat Seeds Development, Danisa M. L. Ferrero, Claudia V. Piattoni, Matías D. Asencion Diez, Bruno E. Rojas, Matías D. Hartman, Miguel A. Ballicora, Alberto A. Iglesias

Chemistry: Faculty Publications and Other Works

Starch is the dominant reserve polysaccharide accumulated in the seed of grasses (like wheat). It is the most common carbohydrate in the human diet and a material applied to the bioplastics and biofuels industry. Hence, the complete understanding of starch metabolism is critical to design rational strategies to improve its allocation in plant reserve tissues. ADP-glucose pyrophosphorylase (ADP-Glc PPase) catalyzes the key (regulated) step in the synthetic starch pathway. The enzyme comprises a small (S) and a large (L) subunit forming an S2L2 heterotetramer, which is allosterically regulated by orthophosphate, fructose-6P, and 3P-glycerate. ADP-Glc PPase was found in a phosphorylated …

Investigation Of Evidence For The Internal Structure Of A Modified Science Motivation Questionnaire Ii (Msmq Ii): A Failed Attempt To Improve Instrument Functioning Across Course, Subject, And Wording Variants, Regis Komperda, Kathryn Hosbein, Michael M. Phillips, Jack Barbera

Chemistry Faculty Publications and Presentations

The Science Motivation Questionnaire II (SMQ II) was developed to measure aspects of student motivation in college-level science courses. Items on the SMQ II are structured such that the word ‘science’ can be replaced with any discipline title (e.g., chemistry) to produce a discipline-specific measure of student motivation. Since its original development as the Science Motivation Questionnaire and subsequent refinement, the SMQ II and its discipline-specific variants have been used in a number of science education studies. However, many studies have failed to produce acceptable validity evidence for their data based on the proposed internal structure of the …

The Geochemical Compositions And Origin Of Sand Dunes In The Olduvai Gorge–Eastern Serengeti Plains, Northern Tanzania, Dalaly Kafumu

Tanzania Journal of Science

This paper reports the composition and origin of black sand dunes that occur in the eastern Serengeti plains near the Olduvai Gorge hominid site in Tanzania.  Grain size analysis reflected light microscopic examination, and scanning electron microscopy (SEM) analysis identified very fine to coarse sand fraction mineral grains of between 0.065 mm and 1 mm, composed of augite, fassaite and omphacite pyroxenes; garnet and sillimanite silicate mineral grains.  The pyroxene minerals (augite, omphacite and fassaite) constitute 95.4% by volume of the sand dunes. The other mineral grains are silicate minerals that include garnet and sillimanite, together form the remaining 4.6% …

Silver-Catalyzed Synthesis Of Disubstituted Fluorinated Isoxazoles, Micah Stewart

Honors Theses

The presence of fluorine can provide organic compounds with useful biological properties, such as increased metabolic stability and drug uptake. Because of these advantages, fluorinated compounds make up about 30% of the drug industry. However, fluorination of complex molecules is difficult due to fluorine’s high electronegativity.

Fluorinated isoxazoles are of particular interest in the pharmaceutical industry. Isoxazoles are five-membered heterocycles with oxygen and nitrogen in the 1, 2 positions that are able to engage in interactions unavailable to other ring structures, conferring advantageous biological properties upon compounds containing them. However, there are limited synthetic routes for fluorinated isoxazoles, and those …

Assessing Differences Between Three Virtual General Chemistry Experiments And Similar Hands-On Experiments, Cory Hensen, Gosia Glinowiecka-Cox, Jack Barbera

Chemistry Faculty Publications and Presentations

To date the efficacy of virtual experiments is not well understood. To better understand what differences may exist between a hands-on learning environment and a virtual learning environment, three experiments were chosen for investigation. For each experiment, approximately half of the students completed a hands-on version of the experiment and the other half completed a virtual version. After completing the given experiment, students were compared on: their ability to meet the learning objectives for that experiment, their responses to six affective scales, and their grade on a laboratory report. Differences were found on four learning objectives. Two of these learning …

Technology-Based Culturally Relevant Chemistry Education (Crce), Mercy Adoma Fosu

Electronic Theses and Dissertations

The relevance of chemistry concepts and principles remains a challenge for most students enrolled in college chemistry courses. Part of this problem is the disconnect with what students experience in their every-day lives, and how the material, specifically chemistry content is presented via textbooks, lectures, and laboratory teaching. Moreover, the teaching of general chemistry has traditionally focused on traditional, instructor-centric expository delivery of course materials, that treats students as empty vessels devoid of prior knowledge. Students prior knowledge and experiences are crucial in shaping their understanding of scientific concepts and principles. Even students with relatively low expectations for success in …

Implementing And Assessing The Use Of A New Strategy For Training Chemistry Graduate Teaching Assistants, Amanda Hyett

Electronic Theses and Dissertations

Graduate teaching assistants (GTAs) largely contribute to undergraduate education but are often underprepared for their role as educators. Most graduate students attend graduate school to perform research and are then asked to teach for the first time without sufficient pedagogy training. To assist in increasing the GTAs pedagogical knowledge, a scenario-based activity series was developed and implemented for first- and second-year GTAs. Developing scenario-based scenarios from actual laboratory events provided GTAs with the opportunity to practice prior to engaging in the laboratory classroom. The Teaching Assistant Intervention Activities (TAIAs) included topics such as interpersonal skills and behaviors, group process, working …

Route Exploration And Synthesis Of The Reported Pyridone-Based Pdi Inhibitor Stk076545, Eric Greve, Sergey V. Lindeman, Christina Scartelli, Lin Lin, Robert Flaumenhaft, Chris Dockendorff

Chemistry Faculty Research and Publications

The enzyme protein disulfide isomerase (PDI) is essential for the correct folding of proteins and the activation of certain cell surface receptors, and is a promising target for the treatment of cancer and thrombotic conditions. A previous high-throughput screen identified the commercial compound STK076545 as a promising PDI inhibitor. To confirm its activity and support further biological studies, a resynthesis was pursued of the reported β-keto-amide with an N-alkylated pyridone at the α-position. Numerous conventional approaches were complicated by undesired fragmentations or rearrangements. However, a successful 5-step synthetic route was achieved using an aldol reaction with an α-pyridone allyl …

A Click-Based Modular Approach To Introduction Of Peroxides Onto Molecules And Nanostructures, Alissa Horn, Patrick H. Dussault

Department of Chemistry: Faculty Publications

Copper-promoted azide/alkyne cycloadditions (CuAAC) are explored as a tool for modular introduction of peroxides onto molecules and nanomaterials. Dialkyl peroxide-substituted alkynes undergo Cu(I)- promoted reaction with azides in either organic or biphasic media to furnish peroxide-substituted 1,2,3- triazoles. Heterolytic fragmentation of the peroxide to an aldehyde, a side reaction that appears to be related to the formation of the triazole, can be suppressed by use of excess alkyne, the presence of triethylsilane, or by use of iodoalkyne substrates. Complementary reactions of simple alkynes with azidosubstituted peroxides are much less efficient. Click reactions of alkynyl peroxyacetals are also reported; reductive fragmentation …

Determination Of Samarium And Dysprosium Solubility, Seana Brennan

Theses and Dissertations (Comprehensive)

In recent years, the use of Rare Earth Elements (REE) has rapidly increased, resulting in numerous potential anthropogenic inputs to the environment. As a result, these metals are emerging as microcontaminants and pose a potential threat to aquatic life. However, the toxicity of REE are largely unknown due, in part, to the limited information on their chemical speciation. The purpose of this project was to gain an understanding of REE precipitate formation and solubility as the foundation for the development of the chemical equilibrium component of toxicity prediction models. Solubility experiments were conducted with Samarium, (Sm), a light REE, and …

Combined Ligand And Structure-Based Virtual Screening Approaches For Identification Of Novel Ache Inhibitors, Kader Şahi̇n, Serdar Durdaği

Turkish Journal of Chemistry

The excessive activity of acetylcholinesterase enzyme (AChE) causes different neuronal problems, especially dementia and neuronal cell deaths. Food and Drug Administration (FDA) approved drugs donepezil, rivastigmine, tacrine and galantamine are AChE inhibitors and in the treatment of Alzheimer's disease (AD) these drugs are currently prescribed. However, these inhibitors have various adverse side effects. Therefore, there is a great need for the novel selective AChE inhibitors with fewer adverse side effects for the effective treatment. In this study, combined ligand-based and structure-based virtual screening approaches were used to identify new hit compounds from small molecules library of National Cancer Institute (NCI) …

Water-Mediated Peptide Bond Formation In The Gas Phase: A Model Prebiotic Reaction, George C. Shields, Ariel Gale, Tuguldur T. Odbadrakh, Tyler Ball

Chemistry Publications

The emergence of life on the prebiotic Earth must have involved the formation of polypeptides, yet the polymerization of amino acids is thermodynamically unfavorable under biologically relevant aqueous conditions because amino acids are zwitterions in solution and because of the production of a water molecule through a condensation reaction. Many mechanisms for overcoming this thermodynamic unfavorability have been proposed, but the role of gas phase water clusters has not been investigated. We present the thermodynamics of the water-mediated gas phase dimerization reaction of glycine as a model for the atmospheric polymerization of amino acids prior to the emergence of biological …

Assessing The Efficacy Of Virtual Experiments In The General Chemistry Laboratory, Cory Jerome Hensen

Dissertations and Theses

As more students enroll in chemistry courses, institutions are faced with increasing costs and limited laboratory space to keep up with the demand. One solution some institutions have turned to is the incorporation of virtual experiments into the curriculum, as this can lower costs and increase the availability of laboratory space. Some institutions have offered sections that complete all of their experiments in a virtual environment, others have offered sections that alternate between a traditional hands-on experiment and a virtual experiment, and some institutions have replaced only select experiments throughout the curriculum with a virtual experiment. To begin to be …

Design, Synthesis, And Self-Assembly Of Supramolecular Fractals Based On Terpyridine With Different Transition Metal Ions, Lei Wang

USF Tampa Graduate Theses and Dissertations

Fractals have existed in a variety of natural forms, and the concept of "fractal geometry" has been developed in many areas by humankind, including art, economics, mathematics, physics, chemistry, material science, and etc. In the field of chemistry, researchers have endeavored great efforts to express the concept using molecules either by theoretical prediction or using synthetic methods in the past few decades, and one successful example is the “Sierpiński triangle”. Challenge still remains to achieve other fractal geometries as well as high generation of fractals with precisely controlled shape and size. Coordination-driven self-assembly has witnessed a wide array of well-defined …

Alignment Of Theoretically Grounded Constructs For The Measurement Of Science And Chemistry Identity, Kathryn Nicole Hosbein, Jack Barbera

Chemistry Faculty Publications and Presentations

Identity has been theorized to aid in student persistence within STEM disciplines. In this study, science and chemistry identity were defined as being recognized as a science or chemistry person within the classroom. To generalize the effects that identity has on student persistence, a measurable construct must be defined, operationalized, and tested in multiple settings with different populations. This project addressed the first step in the process, defining the construct and grounding it in an established theoretical framework. This qualitative project utilized a previously described physics identity framework, with sub-constructs of performance/competence, recognition, and interest, as a starting point for …

Evaluating The Evidence Base For Evidence-Based Instructional Practices In Chemistry Through Meta-Analysis, Md Tawabur Rahman

USF Tampa Graduate Theses and Dissertations

Investigating the effectiveness of instructional practices provides an evidence base to inform instructional decisions. Synthesizing research studies on instructional effectiveness provides an estimate of the generalizability of effectiveness across settings, along with an exploration of factors that may moderate the impact, which cannot be achieved within individual studies. This study sought to provide a synthesis of evidence- based instructional practices (EBIPs) particular to chemistry through meta-analysis. 99 studies were analyzed comprising a broader view of chemistry specific studies than past meta-analyses. The results showed that EBIPs feature a demonstrably positive impact on students’ academic performance in chemistry, although assessment topic …

Assessing Affective Differences Between A Virtual General Chemistry Experiment And A Similar Hands-On Experiment, Cory Hensen, Jack Barbera

Chemistry Faculty Publications and Presentations

To date, few general chemistry laboratory studies have included affective measures despite calls for more research on aspects of this domain. This shortage of studies may be partially due to the scarcity of affective measures that have been designed for, or tested in, the college laboratory setting. To provide measures for use in this environment, several existing affective scales were adapted for this new context. Before data from the scales were utilized to study the environment, evidence was provided for the validity and reliability of the data generated from them. Once sufficient evidence was provided, it was possible to determine …

Development And Evaluation Of A Hybrid Adi/Swh Model Pre-Laboratory Curriculum, Tabitha Alitz, Dawn Del Carlo

Summer Undergraduate Research Program (SURP) Symposium

Previous Research:
• Students value each part of the pre-lab differently, struggle to connect all of the components, and therefore fail to see the big picture
• Students find the pre-lab moderately helpful in understanding both the concepts and mechanics of the lab, but find it less helpful at the end of the semester compared to beginning
• The cognitive load demands of the SWH pre-lab hinders students’ ability to participate in authentic scientific inquiry

Computational Studies Of High-Oxidation State Main-Group Metal Hydrocarbon C-H Functionalization, Clinton R. King

Theses and Dissertations

High-oxidation state main-group metal complexes are potential alternatives to transition metals for electrophilic C-H functionalization reactions. However, there is little known about how selection of the p-block, main-group metal and ligand impact C-H activation and functionalization thermodynamics and reactivity. Chapter 2 reports density functional theory (DFT) calculations used to determine qualitative and quantitative features of C-H activation and metal-methyl functionalization energy landscapes for reaction between high-oxidation state d10s0 InIII, TlIII, SnIV, and PbIV carboxylate complexes with methane. While the main-group metal influences the C-H activation barrier height in a periodic manner, the carboxylate ligand has a much larger quantitative impact …

Studies On Regulation Of Dihydrotestosterone Binding To And Releasing From The Androgen Receptor, Tahyra M. Resto Santos

Theses and Dissertations

The androgen receptor (AR) is a nuclear receptor that responds to testosterone and 5α-dihydrotestosterone (DHT) by modulating gene expression in a variety of cells, including prostate and muscle tissues. Studies of small molecule interaction with AR have shown diphenyl compounds inhibiting through a binding site labeled Binding Function 3 (BF3). The goal of this research is to analyze the interaction of the BF3 site with DDT and related compounds. Amino acids that are exposed on the surface of the BF3 that might interact with different compounds were mutated. Mutant proteins were tested experimentally for their impact on the inhibition the …

Design And Synthesis Of Simplified Analogs Of The Natural Product Sordarin As Potential Antifungal Agents, Yibiao Wu

Dissertations (1934 -)

Invasive fungal infection is a life-threatening illness that causes high mortality, and is especially common among patients with compromised immune systems. However, currently there are only three major classes of clinically useful drugs capable of treating such infections. In addition, due to the fact that drug resistance has become a serious issue especially among patients who suffer from chronic infections, it is urgent to identify new drug candidates, particular those of new classes. The discovery of the natural product sordarin and its novel mechanism of action of inhibiting fungal protein synthesis via the fungal eukaryotic elongation factor 2 (eEF2) led …

Synthesis Of Simplified Azasordarin Analogs As Potential Antifungal Agents, Yibiao Wu, Chris Dockendorff

Chemistry Faculty Research and Publications

A new series of simplified azasordarin analogs was synthesized using as key steps a Diels–Alder reaction to generate a highly substituted bicyclo[2.2.1]heptane core, followed by a subsequent nitrile alkylation. Several additional strategies were investigated for the generation of the key tertiary nitrile or aldehyde thought to be required for inhibition at the fungal protein eukaryotic elongation factor 2. This new series also features a morpholino glycone previously reported in semisynthetic sordarin derivatives with broad spectrum antifungal activity. Despite a lack of activity against Candida albicans for these early de novo analogs, the synthetic route reported here permits more comprehensive modifications …

Metrics And Methods Used To Compare Student Performance Data In Chemistry Education Research Articles, Michael R. Mack, Cory Hensen, Jack Barbera

Chemistry Faculty Publications and Presentations

Quasi-experiments are common in studies that estimate the effect of instructional interventions on student performance outcomes. In this type of research, the nature of the experimental design, the choice in assessment, the selection of comparison groups, and the statistical methods used to analyze the comparison data dictate the validity of causal inferences. Therefore, gathering and reporting validity evidence in causal studies is of utmost importance, especially when conclusions have real policy implications for students and faculty, among other stakeholders. This review examines 24 articles that reported quantitative investigations of the effect of instructional interventions on performance-based outcomes conducted within undergraduate …

Green Chemistry In United States Science Policy, Emily Jarvis

Chemistry and Biochemistry Faculty Works

Although optimizing each of the Twelve Principles of Green Chemistry is necessary for achieving the greenest possible chemistry in the lab, there are additional creative ways to promote green chemistry not encompassed by these. Communicating to society the importance of green chemistry beyond the laboratory is essential. Of course, doing this effectively presents distinct challenges to those encountered when designing chemical syntheses. Here, I discuss several observations from my time working in federal science policy as an American Association for the Advancement of Science/American Chemical Society Congressional Science Fellow in the United States Senate. I suggest a practical science policy …

Synthesis, Characterization, And Nonlinear Optical Properties Of Some New Series Of S-(5-Aryl-1,3,4-Oxadiazol-2-Yl) 2-Chloroethanethioate Derivatives, Zahra Dono Ghezelbash, Hamideh Motiei, Miri Mahmoody, Karim Akbari Delmaghani

Turkish Journal of Chemistry

In the present investigation, some novel S-(5-aryl-1,3,4-oxadiazol-2-yl)2-chloroethanethioate (3a-3e) derivatives were synthesized and their impact on optical properties was studied. They have also been characterized by elemental analysis and various spectroscopic methods including FTIR, $^{1}$H NMR, $^{13}$C NMR, and UV-Vis techniques. The nonlinear refractive indexes of 3a-3e were also measured in dichloromethane via Z-scan method using a continuous wave diode-pumped laser at 532 nm wavelength. The nonlinear refractive coefficient of compounds was obtained from ${10}^{11}\, \, {m}^{{2}}{/W}$ order. Regarding the appropriate nonlinearity of these compounds, they could be considered good candidates for biooptical and photonic applications. All the synthesized compounds (3a-3e) …

Computational Quantum Chemistry Studies Of The Interactions Of Amino Acids Side Chains With The Guanine Radical Cation., Edward Acheampong

Electronic Theses and Dissertations

Guanine is generally accepted as the most easily oxidized DNA base when cells are subjected to ionizing radiation, photoionization or photosensitization. At pH 7, the midpoint reduction potential is on the order of 0.2 – 0.3 V higher than those of the radicals of e.g. tyrosine, tryptophan cysteine and histidine, so that the radical “repair” (or at least, a thermodynamically favorable reaction) involving these amino acids is feasible. Computational quantum studies have been done on tyrosine, tryptophan, cysteine and histidine side chains as they appear in histones. Density functional theory was employed using B3LYP/6-31G+ (d, p) basis set to study …

Chem 360-001 Environmental Chemistry, Alexei Khalizov

Chemistry, Environmental and Forensic Science Syllabi

No abstract provided.

Synthesis And Evaluation Of Densely-Functionalized Troponoids, Danielle R. Hirsch

Dissertations, Theses, and Capstone Projects

Herein, we document our efforts to expand the scope of troponoid synthetic methodology towards densely-substituted scaffolds. This body of work has focused primarily on an oxidopyrylium cycloaddition/ring-opening strategy for the synthesis and biochemical evaluation of troponoids for assistance in a variety of medicinal chemistry studies. In Chapter 1, we outline the use of this synthetic strategy in the profiling of a library of synthetic αHTs against an aminoglycoside antibiotic resistance enzyme known as aminoglycoside-2’’-O-nucleotidyltransferase [ANT(2’’)-Ia]. Enzymatic mechanistic insights have been gleaned from an assessment of troponoid/antibiotic synergistic potential. In particular, two synthetic constructs were identified as promising antibiotic adjuvant candidates, …

Conformationally-Controlled Late-Stage Modifications For Sar Studies Of The C-3-Glcp Moiety Of Ipomoeassin F, Lucas Whisenhunt

Graduate Theses and Dissertations

The resin glycoside, ipomoeassin F has been shown to be extremely potent against multiple cancer lines (IC50 = 4.2-36 nM). However, the mechanism of action of this potent and complex natural product is still not fully understood. The α,β-unsaturated esters of the glucosyl moiety have been shown to be vital for the overall cytotoxicity of ipomoeassin F. Nevertheless, the importance of the tigloyl ester of the glucosyl moiety is still largely unknown. This work aimed to study the pharmacophore importance of the tigloyl ester by creating, an efficient, scalable, and flexible synthesis route for various analogs. The 18-linear step synthesis …