Research shows that the United States of America is losing its competitive stance in the area of STEM (Science, Technology, Engineering, and Math) relative to other countries. One strategy that could solve this problem would be to diversify the field of STEM to include more women of color. The purpose of this narrative, qualitative research study was to explore the lived experiences of Black women with advanced/terminal degrees who are current STEM professionals in Palm Beach County. Fourteen Black women participated in this study, which yielded four major findings that included early exposure to education’s value. importance of a strong sense of self/self-identity, challenges, and discrimination. The hope is that these findings will provide local administrators and elected officials/decision-makers (e.g., the school district, higher education, and government agencies) with information that could advise future practices and policies to close the gap of under-represented Black women in STEM industries. / Includes bibliography. / Dissertation (PhD)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

Syftet med den här undersökningen var att ta reda på om en särskild undervisningsmetod (dvs STEM) påverkar elevernas lust och inställning till matematikämnet. Denna undersökning hade fokus på eleverna, som går i årskurs 2, och deras uppfattning av matematikämnet. Undersökande klass har tidigare knappt jobbat praktiskt med matematiken, det vill säga undervisningsmetoder i form av praktiska lektioner var ett främmande sätt att ha mattelektioner på för klassen. Under denna undersökningen användes metoden triangulering: skriftliga enkäter, deltagande observation och intervjuer var de verktygen som hjälpte att samla in data. Den undersökning hade begränsat med tid, vilket gjorde att det inte fanns tillräckligt med utrymme för att följa attitydens förändringar. Undersökningens resultat visade på att eleverna inte hade en klar uppfattning om att deras vardag är omgiven av matematik. De undersökta eleverna hade en svag begreppsförståelse för teoretisk kontra praktisk kunskap. Den slutsatsen framgick från undersökningens resultat.

Type 1 diabetes mellitus is a metabolic disorder characterized by an autoimmune attack against the insulin producing Beta-cells of the pancreas. Also known as insulin-dependent diabetes, patients must receive exogenous injections of insulin in order to maintain glycemic homeostasis. The necessity of monitoring one’s own blood glucose levels and self-administering insulin is a tedious routine for type 1 diabetics, and this standard treatment option fails to treat any of the underlying causes of the disease. According to van Belle et al, the prevalence of diabetes is rising worldwide amongst all age-groups, from 2.8% in 2000 to an estimated 4.4% by 2030, thus the need to find a more curative treatment approach is eminent. In the emerging field of regenerative medicine, mesenchymal stem cells have been identified as a possible therapeutic tool to replace damaged parenchymal tissue. Along with their ability to modulate the local microenvironment, the introduction of properly differentiated mesenchymal stem cells into patients with Type 1 diabetes may provide a treatment option that helps supplement the lost islet cells without provoking an immune response. Preliminary clinical trials have shown that stem cell therapy decreases the amount of exogenous insulin required daily, decreases fasting glucose levels, decreases amount of glycated hemoglobin and increases C-peptide levels. These four indicators of diabetic control suggest that mesenchymal stem cells are an effective means of helping manage Type 1 diabetes. Still, much research needs to be done to fully understand the biomechanics behind the cells’ actions in order to expand human clinical trials. Although complete insulin independence is rarely achieved in patients receiving mesenchymal stem cell treatment, the promising results shown so far suggest more studies be undertaken in hopes of finding a corrective approach to treat Type 1 diabetes.

Introduction Neurogenesis, the development of new neurons, starts soon after the formation of the neural tube and is largely completed by birth. Development of the brain after birth is mainly reliant on the formation of new connections between surviving neurons. However, adult neurogenesis does continue in the subgranular zone of the hippocampus from quiescent adult neural stem cells. Traditionally neural stem cells were cultured as neurospheres, a heterogeneous agglomeration of neural cells at various stages of differentiation. This heterogeneity prevented accurate quantitative analysis. In 2008 Sun et al produced the first non-immortalised human foetal neural stem (NS) cell line from nine week old human foetal cortex. These cells are cultured as monolayers, have a radial glia like appearance, self renew and form all three neural cell types, neurons, astrocytes and oligodendrocytes upon differentiation. More recently human foetal neuroepithelial like (NES) stem cells have been produced from five week old human foetal hind-brain, they resemble neuroepithelial cells, with characteristic rosettes, upon differentiation they appear to form a pure population of neurons. These homogeneous monolayer cultures enable quantitative proteomic analysis, to increase our understanding of early brain development Methods Three NES and two NS cell lines were available for analysis. They proliferate by stimulation from FGF and EGF, removal of these growth factors results in spontaneous differentiation. Proliferating NES and NS cells were compared using SILAC labelling. In addition, each cell line was differentiated for 12 days, 6 timepoints were taken and compared using label free quantitation. Results 4677 proteins were quantitated with 473 differentially expressed, revealing fundamental differences between NES and NS cells. NES cells are less differentiated, expressing SOX2 and LIN28, have active cell cycle processes, DNA elongation, histone modification and miRNA mediated gene silencing. Whereas NS cells are more developmentally defined, express multiple membrane proteins, have activated focal adhesion, thereby increasing their binding and interaction with their environment. NS metabolism is more oxidative, utilises lipid metabolism, the pentose phosphate pathway and produces creatine phosphate. Upon differentiation the cell cycle processes are downregulated and neurogenic and gliogenic processes increased. Conclusion This work represent a detailed in vitro characterisation of non immortalised human foetal neural stem cells, it describes the regulatory, metabolic and structural changes occurring within neural stem cells in early brain development. The information herein points towards de-differentiation potentially through LIN28-let7, as a means to produce more neurogenic neural stem cells in vitro thus aiding regenerative therapies, as well as provides a wealth of information for better understanding neurological developmental disorders.

We are a collaborative group of K-5 teachers, pre-service teachers, and higher education faculty. In our session we will share our work to design integrated STEM learning units aligned to Tennessee's elementary math and science standards. We will discuss strategies for planning integrated STEM learning as well as use a station format to model interactive, hands-on learning activities. Special emphasis will be placed on math and science standards that may be challenging for teachers.

The physical characteristics (i.e., nanostructure and stiffness) of the extracellular matrix where cells reside have been shown to profoundly affect numerous cellular events in vivo and also been employed to modulate cell behavior in vitro, yet how these physical cues regulate cell behavior is still elusive. Therefore, we engineered a variety of nanotopographies with different shapes and dimensions, and investigated how the nanotopographical cue, through focal adhesions-cytoskeleton-nucleus pathway, affected cell phenotype and function. We further designed and fabricated well-defined substrates which had either identical biochemical cue (adhesive ligand presentation) but different nanotopographical cues or identical nanotopography but different biochemical cues, and dissected the roles of these cues in cell modulation. In addition, we revealed that the human mesenchymal stem cells (hMSCs) could obtain nanotopographical memory from the past culture environment, and the nanotopographical memory influenced the future fate decision of the hMSCs. Moreover, we evaluated the effects of substrate nanotopographical and stiffness cues on the fibrogenesis of human lung fibroblasts in response to carbon nanotubes and highlighted the significance of these physical cues in the development of physiologically relevant in vitro models for nanotoxicological study. The mechanistic understanding of the physical regulation of cell behaviors will provide important insight into the advancement of cell culture technologies and the recreation of biomimetic in vitro tissue/organ models.

The limited treatment options available for heart disease patients has lead to increased interest in the development of embryonic stem cell (ESC) therapies to replace heart muscle. The challenges of developing usable ESC therapeutic strategies are associated with the limited ability to obtain a pure, defined population of differentiated cardiomyocytes, and the design of in vivo cell delivery platforms to minimize cardiomyocyte loss. These challenges were addressed in Chapter 2 by designing a cardiomyocyte selectable progenitor cell line that permitted evaluation of a collagen-based scaffold for its ability to sustain stem cell-derived cardiomyocyte function (“A P19 Cardiac Cell Line as a Model for Evaluating Cardiac Tissue Engineering Biomaterials”). P19 cells enriched for cardiomyocytes were viable on a transglutaminase cross-linked collagen scaffold, and maintained their cardiomyocyte contractile phenotype in vitro while growing on the scaffold. The potential for a novel cell-surface marker to purify cardiomyocytes within ESC cultures was evaluated in Chapter 3, “Dihydropyridine Receptor (DHP-R) Surface Marker Enrichment of ES-derived Cardiomyocytes”. DHP-R is demonstrated to be upregulated at the protein and RNA transcript level during cardiomyogenesis. DHP-R positive mouse ES cells were fluorescent activated cell sorted, and the DHP-R positive cultured cells were enriched for cardiomyocytes compared to the DHP-R negative population. Finally, in Chapter 4, mouse ESCs were characterized while growing on a clinically approved collagen I/III-based scaffold modified with the RGD integrin-binding motif, (“Collagen (+RGD and –RGD) scaffolds support cardiomyogenesis after aggregation of mouse embryonic stem cells”). The collagen I/III RGD+ and RGD- scaffolds sustained ESC-derived cardiomyocyte growth and function. Notably, no significant differences in cell survival, cardiac phenotype, and cardiomyocyte function were detected with the addition of the RGD domain to the collagen scaffold. Thus, in summary, these three studies have resulted in the identification of a potential cell surface marker for ESC-derived cardiomyocyte purification, and prove that collagen-based scaffolds can sustain ES-cardiomyocyte growth and function. This has set the framework for further studies that will move the field closer to obtaining a safe and effective delivery strategy for transplanting ESCs onto human hearts.

Isocitrate Dehydrogenase-1 has been found to be mutated in over 70% of lower grade gliomas and has become an important diagnostic tool for tumor prognosis, however its role in glioma development, and its impact on response to therapy, is still not fully understood. Unmutated IDH1 functions to convert isocitrate to alpha-ketoglutarate (a-KG) in the tricarboxylic acid (TCA) cycle. Mutated IDH1R132H changes the enzymatic equilibrium and converts a-KG to 2-hydroxyglutarate (2-HG), an oncometabolite. IDH1R132H mutated tumors show an elevated production of 2-HG and epigenetic alterations in DNA and histone methylation. This mutation is predominantly seen in the proneural glioma subtype in which oligodendrocytes progenitors (OPCs) are considered the cell of origin due to phenotypic similarities. The effect of IDH1R132H mutation in cellular transformation has not been fully established. Epigenetic modifications connect genotype to phenotype by genetic expression alterations and epigenetic modifications are necessary for OPC differentiation. Tri-methylation of lysine residue K27 on histone H3 (H3K27me3) is a repressive mark associated with cell pluripotency. H3K27me3 is trimethylated by Enhancer of Zeste 2 (EZH2) and demethylated by the a-KG-dependent demethylases UTX/KMD6A and JMJD3/KDM6B. 2-HG is a competitive inhibitor of a-KG-dependent demethylases, providing a mechanistic link between IDH mutations and increases H3K27me3 by inhibiting demethylation. In this thesis, we evaluated the epigenetic changes in mouse models of IDH mutant and wildtype glioma and genetically-transformed OPCs and tested the effects of drugs that target specific epigenetic marks. We developed a mouse model of glioma to compare IDH1R132H cells to wildtype glioma cells and found that although there was no difference in survival, IDH1R132H gliomas have increased levels of 2-HG by MALDI-IMS and metabolomic analysis. Interestingly, based on RNA-sequencing analysis our IDH1R132H model has a more OPC-restricted expression profile compared the wildtype glioma model which have higher enrichment of genes from other cell lineages, including neurons, astrocytes, myelinating oligodendrocytes and microglia. We used the EZH2 inhibitor (Tazemetostat, EPZ-6438) and found that this treatment was not cytotoxic or cytostatic to our cells although H3K27me3 was reduced. Interestingly, Tazemetostat treatment increased the expression of non-OPC genes (genes normally expressed by other lineages as assessed using the Barres transcriptomic database). To better understand how IDH1R132H influences OPC transformation, we transformed OPCs in vitro. OPCs were isolated from floxed p53 postnatal day 5 mice from and retrovirally infected with viruses to delete p53 alone or to also express IDH1R132H. OPCs that express IDH1R132H had increased levels of 2-HG by metabolomics and showed alteration in H2K27 methylation and acetylation that resembled those seen in glioma cells. Standard methods of western blot analysis consist of analyzing whole cell lysate, cytoplasmic and nuclear fractionation, or histone acid extraction. To analyze both the cytoplasmic fraction as well as histone modification, I developed a cellular extraction method in which cells were fractionated and the nuclear fraction was acid extracted. This method allows for the analysis of both cytoplasmic proteins as well as histone modifications by western blot. Using this method, we found that treating glioma cells or OPCs with synthetic cell permeable octyl-2HG, or expressing IDH1R132H, caused cells to have increased H3K27me3, while treatment with Tazemetostat caused a decrease in H3K27me3. Based on the RNA-sequencing data we found that increased H3K27me3 (ID1R132H mutation) express more OPC-like phenotype while reduced H3K27me3 (Tazemetostat treatment) induced an upregulation of genes associated with other lineages making them less restricted to the OPC transcriptional phenotype. We found that in both the glioma cells and OPCs, Tazemetostat treatment decreased H3K27me3 and increased H3K27ac. Based on the increase of H3K27ac after Tazemetostat treatment, we hypothesized that a Histone deacetylase inhibitor (HDACi) would be synergistic. We found that although the HDACi Panobinostat was less cytotoxic to IDH1R132H mutated glioma cells and OPCs, co-treatment with Tazemetostat is synergistic in mutant and wildtype models. We also saw that in IDH1R132H ex vivo slices, the co-treatment reduced tumor marker composition. These findings point to a novel therapeutic strategy for IDH1-mutated proneural gliomas that targets the specific epigenetic alteration in these tumors.

Cardiac stem cells (CSCs)-based therapy provides a promising avenue for the management of ischemic heart diseases. However, engrafted CSCs are subjected to acute cell apoptosis in the ischemic microenvironment. Here, stem cell antigen 1 positive (Sca-1+) CSCs proved to own therapy potential were cultured and treated with H2O2 to mimic the ischemia situation. As autophagy inhibitor, 3-methyladenine (3MA), inhibited H2O2-induced CSCs apoptosis, thus we demonstrated that H2O2 induced autophagy-dependent apoptosis in CSCs, and continued to find key proteins responsible for the crosstalk between autophagy and apoptosis. Nuclear Receptor Subfamily 4 Group A Member 2 (NR4A2), increased upon cardiomyocyte injury with unknown functions in CSCs, was increased by H2O2. NR4A2 siRNA attenuated H2O2 induced autophagy and apoptosis in CSCs, which suggested an important role of NR4A2 in CSCs survival in ischemia conditions. Reactive oxygen species (ROS) and NF- κB (P65) subunit were both increased by H2O2. Either the ROS scavenger, N-acetyl-lcysteine (NAC) or NF-κB signaling inhibitor, bay11-7082 could attenuate H2O2-induced autophagy and apoptosis in CSCs, which suggested they were involved in this process. Furthermore, NAC inhibited NF-κB activities, while bay11-7082 inhibited NR4A2 expression, which revealed a ROS/NF-κB/NR4A2 pathway responsible for H2O2- induced autophagy and apoptosis in CSCs. Our study supports a new clue enhancing the survival rate of CSCs in the infarcted myocardium for cell therapy in ischemic cardiomyopathy.

Background. Relapsed acute promyleocytic leukemia (APL) is treated with re-induction chemotherapy, commonly arsenic trioxide, and stem cell transplantation (SCT). The effect of arsenic trioxide on autologous peripheral blood stem cell collection is unknown. Procedure. Five pediatric patients with relapsed APL had PML-RARA negative peripheral blood stem cells mobilized (four after arsenic trioxide) and underwent autologous SCT after cyclophosphamide (60 mg/kg x 2) and total body irradiation (TBI-fractionated 1,200 cGy) conditioning. Results. All five patients remain in molecular remission a median of 20 months post-transplant. Conclusion. Autologous SCT performed during molecular remission is a treatment option for pediatric patients with relapsed APL and may provide durable leukemia-free survival without the complications of allogeneic transplantation.