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How Teachers Perceive Teacher Leadership in a Massachusetts Urban Turnaround High School: A Concurrent Mixed-Methods Case Study
Get PDFTurnaround schools represent a strategy for swiftly revitalizing underperforming educational institutions. This study examined how teachers perceived the role of teacher leadership within one urban turnaround high school. The study addressed the following research questions: 1. How do teachers within an urban turnaround high school conceptualize the role of teacher leadership? 2. In what ways does teacher leadership influence and contribute to the improvement of student performance in turnaround schools? This research was conducted through a concurrent mixed-methods case study that involved one urban turnaround high school. The findings offer valuable insights into teachers\u27 perceptions of teacher leadership and its impact on school improvement initiatives. The results also have implications for refining state policies in Massachusetts concerning turnaround schools, facilitating positive transformations in the roles of teacher leaders within such educational settings
Multicomponent and Sequential Radical Reactions for the Synthesis of Functionalized Heterocyclic Compounds
No full textThe GBB-3CR is highly efficient in synthesizing the N-bridgehead heterobicyclic core associated with biologically interested compounds. This work presents a new method for the synthesis of the 3,5-dihydro-4H-1,2a1,3-triazaacenaphthylen-4-one scaffold by sequential GBB/N-Acylation/Radical cyclization reactions. A series of etherate reactants were used for the radical addition and cyclization reactions. The addition of ZnCl2 was found critical during the radical reaction. The substrate scope was demonstrated in the synthesis of 19 functionalized heterocyclic compounds
Revelations in the Enzymatic Degradation of Alkanesulfonates: Structural and Biochemical Insights into C-S Bond Cleavage from Two-Component Flavin-Dependent Monooxygenases SsuD and MsuD
No full textAnthropogenic sulfur pollution has contributed to major threats of environmental and human health concerns which only continue to be emitted to the biosphere and disrupt the global sulfur cycle. This dissertation dives into the research surrounding part of a potential response in mitigation and remediation of organosulfur pollutants. Living organisms are able to catabolize a plethora of different compounds, including many pollutants, and the products can be utilized for metabolic processes. Under the bacterial sulfur starvation response, sulfur assimilation pathways enable certain bacteria to intake and breakdown various organosulfur compounds, in part through remarkable and atypical flavoproteins known as two-component flavin dependent monooxygenases. By studying such systems, the potential for application in bioremediation and prevention of emissions of organosulfur pollutants is apparent. The structural and mechanistic studies here represent original knowledge into the incomplete information surrounding the enzymatic degradation of alkanesulfonates of the often-overlooked family of flavin-dependent monooxygenases. Investigations into the alkanesulfonate monooxygenase MsuD yielded crystal structures with various combinations of alkanesulfonates and flavin in different redox states. These structural studies, along with biophysical and functional characterization, confirm MsuD is a homotetramer that acts on short-to-medium length alkanesulfonates and has a structure analogous to other class C flavoprotein monooxygenases. These studies also reveal a novel function for the extended C-terminus of MsuD in catalysis, oligomeric shifts in quaternary state upon ligand binding, and differences in flavin redox state conformations that likely are important for preferred binding of the substrate form, reduced flavin mononucleotide. Through enzyme functional assays, biophysical studies, and the first crystal structures of the MsuD from Pseudomonas fluorescens with and without ligands in different redox states, a wealth of knowledge on MsuD can now be utilized in numerous ways and contributes much to our understanding of two-component flavin dependent monooxygenases
Insights into the Sulfur Assimilation Pathway of Dimethylsulfone During Sulfur Starvation in Pseudomonas fluorescens: Structural and Biophysical Analysis of Two-Component Flavin-Dependent Monooxygenases SfnG and MsuC
Get PDFSulfur is essential for life, playing a critical role in metabolic functions and cellular signaling pathways. While bacteria typically obtain sulfur from inorganic sulfate, they must resort to alternative sources when sulfate is limited. Pseudomonads have evolved a sophisticated system to address this challenge, employing two-component flavin-dependent monooxygenases (TC-FMOs) to assimilate sulfur from alkanesulfonates and dialkylsulfones, such as dimethylsulfone (DMSO2). This process is triggered by a stress response during sulfur starvation conditions. To convert DMSO2 into bioavailable sulfite, Pseudomonads perform a series of chemical transformations regulated by the msu and sfn operons. This dissertation investigates the mechanisms underlying these transformations in Pseudomonas fluorescens, focusing on the TC-FMOs responsible for DMSO2 catabolism. The insights gained from this research have potential applications in bioremediation and may contribute to our understanding of human health in relation to other Pseudomonas species. The msu and sfn operons encode the two-component flavin-dependent monooxygenases (TC-FMOs) SfnG, MsuC, and MsuD, along with the FMN reductase MsuE, which collectively catalyzes the catabolism of dimethylsulfone (DMSO2) to sulfite. This dissertation provides an in depth structural and biophysical investigation into the function of SfnG and MsuC, which convert DMSO2 to methanesulfinate (MSI–) and MSI– to methanesulfonate (MS–), respectively. Multiple high-resolution crystal structures of SfnG revealed critical protein regions that become ordered upon binding of the ligands FMN and DMSO2. The placement of ligands identified a putative oxygen binding site, suggesting SfnG may employ an N5-(hydro)peroxyflavin for oxidative cleavage of the C–S bond of DMSO2. Functional biochemical experiments support the use of an N5-(hydro)peroxyflavin intermediate, and biophysical studies reveal the complexities of ligand binding to SfnG. The second enzyme in the pathway, MsuC, catalyzes the oxidation of MSI– to form MS– through S–O bond formation. Structural analysis confirms that MsuC belongs to the two-component flavin-dependent monooxygenase (TC-FMO) family and likely employs C4a flavin chemistry for catalysis. A high resolution unliganded structure, combined with computational studies, revealed a putative MSI– binding pocket with features that allow for binding of this negatively charged molecule. Further structural analysis, including alignments with homologous enzymes, uncovered conserved C-terminal interactions that stabilize the active site and are connected to substrate binding. These structural inferences provide a foundation for future functional studies, which will enhance our understanding of MsuC’s catalytic mechanism and substrate binding dynamics. Additionally, biophysical characterization has yielded new insights into the role of FMN binding in enzyme stability and function. The high-resolution structures of SfnG with bound FMN and DMSO2, as well as MsuC, have provided valuable insights into these enzymes. Detailed characterization of their structures and active sites enables targeted mutational analyses to elucidate substrate specificity and promiscuity. Notably, these systems are prevalent in various Pseudomonas strains, including opportunistic, multi-drug resistant pathogens like Pseudomonas aeruginosa. Given that SfnG and MsuC catalyze C–S bond cleavage and S–O bond formation, respectively, future studies could explore modulating their activities to target other compounds, such as those containing C–Si bonds or persistent environmental contaminants like polyfluoroalkyl substances (PFAS). This research not only advances our understanding of bacterial sulfur metabolism but also opens avenues for potential biotechnological and environmental applications
Hired for Diversity and Onboarded for Assimilation: A Case Study of Racial Battle Fatigue Among Student Affairs Practitioners of Color
Get PDFThis study addressed the need to understand the negative experiences of student affairs practitioners of color (SAPOCs) related to racial battle fatigue (RBF) and the accompanying need to explore how SAPOCs working at predominately white institutions (PWIs) experience RBF. The author conducted a multiple-case study with 10 SAPOCs, who served as individual cases, and used semi-structured interviews and document analyses of institutional websites. The conceptual framework for this study was framed by racialized organizations (Ray, 2019), campus racial climate (Hurtado et al., 1998), and RBF (Smith et al., 2007). Findings indicated that while the 10 participants worked at different PWIs and had distinct office and institutional climates, they shared similar experiences with RBF. Each participant talked about the visceral impact of navigating their workplace as a staff member of color, their fear of confirming stereotypes, and/or the mental toll of debating internally whether they had been microaggressed as they navigated their workplace. The study participants were persistently reminded that they were different in their predominately white workspaces and they endured frequent disrespect about their appearance (e.g. hair). Participants revealed they could do the work that they were assigned but also articulated the negative impact RBF was having on them as they would complete their work tasks and manage their RBF. Ultimately, this led participants to have a mix of responses about whether they felt a sense of belonging at work and in which settings they felt the most sense of belonging. Participant experiences with RBF while working at PWIs included a lack of support at different levels (i.e. supervisor, department, or institution) of their professional journeys and a lack of racial representation in their white workplaces. Lastly, participants were evenly split on whether they would leave or remain in the field of student affairs and higher education. This study has outlined the importance of understanding the influence of the PWI environment on SAPOC and RBF. SAPOCs are inherently harmed when an institution focuses solely on increasing its compositional diversity without reflecting on the practices embedded in its culture and climate. The powerful stories shared by the participants led to suggestions for future research and several recommendations for institutions, departments, and SAPOCs to contribute to/improve to the wellbeing, working conditions and/or retention of SAPOCs
Consistent Seeds: Assessing Stability and Changes in Fodder at Farmsteads in Northern Iceland
Get PDFThis thesis examines foddering strategies at farmsteads in Hjaltadalur, a valley in northwestern Iceland, from about AD 870-1300. Fodder, animal food that farmers grow or forage, is important because it was central to the Viking Age and medieval Icelandic economy. During this period, Iceland was primarily a subsistence-based economy with a heavy reliance on animal products. Keeping animals alive and healthy through long winters was potentially an important factor in creating differential wealth. A major part of ensuring animals survived was having sufficient nutritious animal food. Furthermore, during this period, Iceland saw major environmental, political, and socio-economic changes. In AD 1106, as part of the adoption and institutionalization of Christianity, Hólar (a farmstead in the middle of Hjaltadalur) became a bishopric and would go one to become one of the most powerful farms in Iceland. Seeds, that reflect foddering strategies, were recovered and analyzed from flotation samples taken at nine Hjaltadalur household middens at farmsteads that were occupied both before and after the establishment of the bishopric. To assess any differences associated with the establishment of the bishopric, the seeds were divided into four environmental zones. The household midden seed samples were stratified based on a volcanic tephra (ash) layer that fell in AD 1104 and is widely preserved in the region. Because the tephra layer is coeval with the bishopric establishment, assemblages from neighboring farmsteads before and after its establishment can be compared. The comparison of seed assemblages indicates that on a valley-wide level, there is no significant change in seed metrics over time. This environmental seed similarity suggests relatively consistent foddering strategies. The continuity is remarkable given the social, economic, and environmental change and speaks to the profound stability and robust adaptation of these Icelandic farmsteads during rapidly changing social and environmental conditions. While foddering strategies seem to be consistent across the founding of the bishopric, individual farms have substantial variation in their seed metrics across the sampled space and time. Many of these seed metrics correlate with other farmstead metrics, such as elevation, eighteenth century tax value, and area occupied
Aging in Maynard: A Community Needs Assessment
Get PDFThis report describes research undertaken by the Center for Social & Demographic Research on Aging (CSDRA), within the Gerontology Institute at the University of Massachusetts Boston, on behalf of the Town of Maynard. The report supports the Council on Aging’s objective to identify and serve the needs of residents age 50 and older. The contents of this report are meant to inform the Town of Maynard, the Maynard Council on Aging (COA), the Senior Center, and organizations that work with and on behalf of older residents of Maynard for the purposes of COA mission fulfillment alongside planning and coordination of services for current and future needs of residents. The report will also help to build awareness about issues facing Maynard among community members at large
Keeping in Touch with Program Graduates
Get PDFThese document focuses on the tips on the importance of setting clear expectations, collecting reliable contact information, using technology to stay connected, building personal relationships, and building follow-up efforts into alumni initiatives for the program graduates
By the Bootstraps: Transformations in Class, Mobility, and the Shoe Industry in 19th Century Grafton, Massachusetts
No full textDespite rivaling textiles as the most lucrative industry in 19th-century New England, the production of boots and shoes has received little attention from archaeologists, who instead have concentrated on company housing associated with textile mills. Since the industrialization of the shoe industry relied more heavily on the division of labor than the development of factories, the archaeological signature of shoemaking is relatively ephemeral, creating an academic bias towards the study of shoes in domestic rather than commercial contexts. Therefore, the presence of shoemaking tools at the Hassanamesit Woods Augustus Salisbury site in Grafton, Massachusetts offers a unique opportunity to investigate changes in the shoemaking process, thus shifting the historical narrative away from an individual experience of consumerism and towards a collective experience of industrialization. Extensive documentary analysis provides insights into the consequences of industrial transition, revealing patterns of geographic and socioeconomic mobility amongst the class of laborers that lived and worked at the site from 1850 to 1890. Ultimately, this analysis of shoemaking tools and census data reveals patterns in the collective experience of a highly mobile working class who engaged in agricultural and industrial labor and leveraged the domestic arrangement at HWAS in an attempt to gain economic independence
The Study of DMRT1 in Zebrafish and How it Impacts Sex Determination
Get PDFThe dmrt1 gene is common amongst most animals and functions to determine or maintain male sex during development. Similarly, in zebrafish dmrt1 is important for male sex determination and maintaining proper testis morphology. This gene is expressed in two different cell types of the testis in zebrafish, germ cells and Sertoli cells. While we know where this gene is expressed and what its role is, it is not known if it is sufficient to drive male fate. If so, then in which cells is it sufficient to drive male fate in the testis? I aimed to answer this question by analyzing two different dmrt1 transgenic lines that express dmrt1 specifically in either the germ cells or the Sertoli cells. We then analyzed sex ratios of the transgenic fish compared to the wild-type siblings. We found that dmrt1 overexpression in both cell types leads to an overwhelming male bias in the population as compared to wild type fish. We also found that dmrt1 overexpression exclusively in the germ cells led to a higher frequency of males in comparison to the wild type fish. Meanwhile, dmrt1 overexpression exclusively in the Sertoli cell led to no change in the number of males compared to wild type fish. I then wanted to see if the dmrt1 gene was sufficient to rescue male fate in dmrt1 mutant zebrafish. After testing out the individual transgenic lines against mutant dmrt1 fish, we found that neither transgene by themselves could rescue the male sex determination defects in the progeny of mutant fish. Combining all of these data together, we see that dmrt1 overexpression in the germ cells is sufficient to drive male sex determination. However, dmrt1 expression from each of our transgenic lines is not sufficient to drive male sex determination, under dmrt1 mutated conditions in the zebrafish testis