6834 research outputs found
Sort by
The total synthesis of (+)-alterbrassicicene C, the total synthesis of (-)-alterbrassicicene B and (+)-3-ketobrassicicene W.
No full textIn 2020, Zhang and colleagues reported the isolation of the fusicoccane diterpenoids (+)-alterbrassicicene C, (-)-alterbrassicicene B, and (+)-3-ketobrassicicene W in Anhui province, China from the necrotrophic fungal pathogen Alternaria brassicicola which had been found on the leaves of siegesbeckia pubescens. The structures of (+)-alterbrassicicene C and (-)-alterbrassicicene B were found to possess novel tetracyclic scaffolds comprised of embedded and stereocomplex oxa-[3.3.1]-bicyclononanes. Intrigued by their architecture and the possible synthetic challenges presented by these natural products, we developed a synthetic route that led to the enantioselective total synthesis of (+)-alterbrassicicene C in a 20-step longest linear sequence. Key to our strategy was the preparation of a fused 5-8-5 carbocyclic intermediate that would be advanced via a transannular oxygen transfer involving an initial transannular haloetherification, followed by a silver promoted ethereal migration, novel Lewis acid promoted SN1’ THF opening, and an oxa-Michael/ retro-oxa-Michael cascade. The synthesis was then completed by way of an alkyl-Stille cross coupling to append the methoxy methyl arm, a Meinwald rearrangement, and a diastereoselective radical dehalogenation.
Having succeeded in the total synthesis of (+)-alterbrassicicene C, we turned toward developing a divergent synthetic approach to (-)-alterbrassicicene B and (+)-3-ketobrassicicene W that would employ oxidation state manipulation of previously prepared advanced intermediates. The major challenge in this latter effort proved to be setting the stereochemistry of the three-contiguous stereocenters residing in and about the cyclopentanone. These efforts unfortunately were thwarted, and a new synthetic strategy was developed that addressed this latter issue via the preparation of enantioenriched vinyl bromides, prepared through a novel SN2’ addition between an activated cyclopentene and alkenyl cuprate. The completion of these natural products was predicated on establishing the requisite stereotriad in the southern portion of the cyclooctane, leveraging facial bias through a series of diastereoselective hydration, oxidation, and reduction events. Turning to (+)-3-ketobrassicicene W, we employed a sequence of reductive THF opening followed by elimination of a b-TMS ether. The latter natural product was then advanced to form (-)-alterbrassicicene B by way of a transannular oxa-Michael addition, completing the enantioselective total synthesis of these natural products in 17- and 18-steps longest linear, respectively
Older adults : views on later-in-life romantic relationships.
No full textOlder adults are extremely susceptible to loneliness, especially after experiencing the end of a marriage. Thus, the goal of this study is to understand how older adults view later-in-life romantic relationships as a way of receiving affection. This qualitative study collected data from divorced or widowed adults ages 65 and older throughout the United States (N= 20). Semi-structured, in-depth interviews, narrative style interviews found that older adults view later-in-life romantic relationships as companionship, an interruption, scary, out of time, impossible, and supported. This study provides insight on how older adults view romantic relationships and shows what they may be looking for in a relationship
Advancements in in-situ resource utilization through the use of twin rod additive friction stir deposition.
No full textAdditive manufacturing has the capability to converge multi-materials, create sustainable engineering, and pioneer sciences to achieve its goals at the point-of-need. One such technology is the solid-state additive process called Additive Friction Stir Deposition that has been shown to enable the direct recycling of in-situ resources. In-situ resource utilization is a sustainability paradigm that facilitates the use of materials found locally at the point of need. In-situ resources utilization coupled with direct recycling of scrap materials at the point of need can be used to provide sustainable manufacturing that will enable in-space, servicing, assembly, and manufacturing (ISAM). Research surrounding additive friction stir deposition has shown it is capable of incorporating feedstock in a wide variety of forms such as scrap, damaged material, powders, and machine chips. This makes the process ideal for in-situ resource utilization. The presented work will cover research that seeks to use Twin Rod Additive Friction Stir Deposition to produce composites fabricated with lunar regolith simulant at different weight percentages. As the space industry attempts to move toward establishing a more permanent presence on the moon, additive methods capable of harnessing local natural resources will be desired. Therefore, this work discusses and covers the practicality of manufacturing lunar regolith metal composite fabrication via twin rod additive friction stir deposition. It involves composite characterization methods, a material parameter sustainability study, and nondestructive evaluation techniques used to corroborate AFSD’s advantages of its use for in-space additive manufacturing
First-generation Hispanic college students’ perceptions regarding their college readiness skills : a multiple case study.
No full textFirst-generation Hispanic college students face unique challenges in their journeys to college. Being college-ready is crucial for first-generation Hispanic students, as it affects their educational journeys and future careers. Being college-ready entails many skills; therefore, high school principals, counselors, teachers, Hispanic families, and other interested parties have an important role in ensuring that first-generation Hispanic students are prepared when they graduate from Texas public high schools. The purpose of this qualitative multiple case study was to understand how Conley’s (2012) four keys to college and career readiness influence the perceived success of four Hispanic first-generation college students in completing their first year of college. I used David Conley’s (2012) four keys to college and career readiness as the framework for the study. Conley’s (2012) keys to college and career readiness include cognitive strategies, content knowledge, learning skills and techniques, and transition knowledge and skills. The research question used in this study was: In what ways do Conley’s (2012) four keys to college and career readiness influence first-generation Hispanic students’ perceived success in completing their first year of college? This study had five key findings which revealed the participants’ perceptions. First, first-generation Hispanic student participants perceived that critical thinking helps them solve problems. Second, first-generation Hispanic student participants perceived that prior knowledge from previous courses helps them understand the content and prepare them for future courses and careers. Third, first-generation Hispanic student participants perceived that taking ownership of their education, being organized, and time management skills are crucial in college. Fourth, first-generation Hispanic participants perceived that they received a lack of high school support in researching, planning, and applying for college. Fifth, first-generation Hispanic participants perceived that the family support they received in their journey to college was critical to their success. The findings of this qualitative multiple case study have implications and recommendations for several key decision-making groups
Transitioning out of sports : the identity shifts of former collegiate athletes after leaving their sports.
No full textThis study examines the transition experiences of former student-athletes who leave their sport and adjust to college life beyond athletics. Through interviews with nine former student-athletes, the research highlights shifts in identity, changes in motivation, and the process of self-discovery. Utilizing Schlossberg's (1984) Four S's Student Transition Theory, this study emphasizes the role of personal strategies and external support in helping former student-athletes connect to their university, maintain their well-being, and successfully reintegrate into campus life. These findings provide valuable insight into how universities can support student-athletes during their transition and inform future research on the unplanned exit from sports
Stolen identity : a qualitative single case study on the relationship between Indian boarding school stories and perceptions of formalized education systems.
No full textMany Native American students struggle with poverty, absenteeism, discrimination, and high suicide rates, all of which create barriers to academic success. Standardized test scores reveal that Native American students consistently underperform compared to their white peers, and the graduation rate for Native American students remains significantly lower. Obstacles to success at school relate to historical trauma. One source of historical trauma for Native American people is Indian Boarding Schools. The historical influence of Indian Boarding Schools continues to shape the challenges faced by Lakota students in formal education systems today. These lingering symptoms of the historical trauma of Indian Boarding Schools are multigenerational. Without addressing these deep-seated issues, Lakota students will continue to face systemic disadvantages within the U.S. education system.
This study used a qualitative case study design to explore the relationship between hearing stories of Indian Boarding Schools and how those relate to perceptions of formalized education systems. Participants were chosen based on specific criteria for interviews and a focus group. The theoretical framework chosen for this study was Tribal Critical Race Theory. Tribal Critical Race Theory has nine tenets, though I focused on three for this study. This study examined the relationship between hearing stories of Indian Boarding Schools and perceptions of formalized education systems.
Participants associated hearing traumatic Indian Boarding School stories with distrust in formal education settings aligning with research on historical trauma. Themes in this study include the power of stories, colonial power, healing and trust, and kinship or family roles. Teachers and administrators who teach Native American students either on or off reservations can benefit from learning the history of Indian Boarding Schools and working to build trust with families and communities to address the generational distrust in formal education settings. This study can bring hope for a relationship between Native American people and formalized school systems because all four participants acknowledged that healing must happen, although their ideas on how to heal varied. The findings of the study could help teachers of Native American students to help build relationships and begin finding a way to rebuild trust with Native American communities
Middle school teachers' perspective on their use of culturally relevant education practices in their classrooms : a qualitative case study.
No full textThe primary mission of public school districts is to provide education for all students, regardless of their background, race, or socioeconomic status (Bonner et al., 2018). Research indicates that in educational environments where educators refrain from employing culturally relevant pedagogy, students will encounter diminished academic performance, heightened disciplinary issues, and an increased sense of alienation from the school community (Bonner et al., 2018; Eddie, 2021). Research reveals that a limited number of K–12 public school teachers implement culturally relevant teaching practices to equip students of color with the skills necessary to advocate for social justice.
This qualitative case study explored the perceptions of four middle school teachers regarding the extent to which they use culturally relevant educational practices to create spaces where all students, especially those of color, are better able to engage in the academic learning process. The theoretical framework of culturally relevant education or CRE (Aronson & Laughter, 2016) shaped the data collection process, serving as the basis for semi-structured interview questions, questionnaires, and focus group inquiries.
Each of the four participants provided rich narrative data regarding applying CRE strategies to enhance student engagement in their classrooms. The data analysis revealed four key findings that align with my theoretical framework. The first finding indicated that participants utilized the district curriculum as a foundation and enhanced students’ cultural awareness and acceptance through supplementary materials. The second finding demonstrated that participants encouraged students to share their cultures and learn from their peers. The third finding revealed that participants created an emotionally safe classroom environment, allowing students to express their cultural experiences freely. Lastly, the fourth finding highlighted that the participants allocated time to dismantle misconceptions and stereotypes perpetuated by media and family influences within the classroom.
The findings have significant implications for key decision-makers. Recommendations include expanding culturally responsive education across school districts, training administrators on racial inequities, and enhancing educators’ self-awareness to promote equitable learning environments. Additionally, fostering open communication with families and the community is crucial. Finally, educators should have more opportunities to engage inC CRE practices to enhance their instructional methods
Wanderlust within : a qualitative study of internal motivating factors shaping study abroad decisions among underrepresented U.S. college students.
No full textIn an increasingly globalized world, international education remains critical, yet for a century the percentage of college students who participate in U.S. study-abroad programs (SAPs) has seen little change. Although U.S. college enrollment has increased significantly over the past century, over 98% of students still do not participate in an international education program, revealing a persistent gap despite the expansion of opportunities. SAP opportunities have expanded worldwide over the past 40 years; however, participation peaked in 2018–2019 at just 1.8% of U.S. college students. Among the low percentage of U.S. college students who study abroad, there is an underrepresentation of students across gender, race/ethnicity, and academic major. Participants in this study had one or more characteristics of traditionally underrepresented college students in U.S. SAPs (e.g., male students, students of color, or students majoring in education).
This instrumental single case study examined the perceived reasons why students from three historically underrepresented groups in SAPs considered participation and how they ultimately decided whether to study abroad. The study involved six students from one 4-year university: three who participated in an SAP and three who did not. Participants met eligibility criteria of full-time enrollment, identification as male, a person of color, an education major, or a combination of these, and serious consideration of SAP participation. Personal Investment Theory (Maehr & Braskamp, 1986) provided the framework for the research questions, data collection, and analysis, which utilized a questionnaire and semi-structured interviews.
This case study yielded six key findings with implications for students, parents, educational leaders, employers, and researchers. Students who considered study abroad exhibited an active, extroverted nature and a sense of independence. They demonstrated awareness of SAP opportunities, program appeal, timing, worldview, and family support, while being motivated by aspirations for new knowledge, cultural experiences, personal transformation, meaningful connections, and professional development. Among those who studied abroad, self-efficacy and institutional support were common traits, whereas those who did not participate cited apprehension, awareness of personal learning differences, logistical barriers, programmatic and academic challenges, and perceived a lack of institutional support
Dancing with the archive : preservation, circulation, transformation.
No full textThis thesis explores the intersection of performance documentation, particularly in dance, and GLAM institutions (Galleries, Libraries, Archives, and Museums). Challenging traditional archival models that prioritize permanence and tangible artifacts, it examines how dance is preserved, circulated, and transformed through institutional frameworks. The study is structured around three key phases: preservation, which considers archival methods such as notation, photography, and oral histories; circulation, which explores artist-driven and digital archives as dynamic tools for engagement; and transformation, which investigates the role of scenography and museum exhibitions in activating performance remains. Through historical and contemporary case studies, this research argues that performance documentation is not merely a record of the past but a living, evolving process that extends and reconfigures the legacy of dance. By tracing the institutionalization of performance, this thesis sheds light on the evolving relationship between performance, memory, and the archive
Constructing a stakeholder-driven model of working alliance between caregivers and juvenile probation officers : a qualitative approach.
No full textJustice-involved youth have high rates of mental health and substance use challenges, but they face significant barriers to accessing and participating in treatment. To address these barriers, the juvenile justice system has shifted the responsibilities of juvenile probation officers (JPOs) to include the use of evidence-based intervention strategies, and caregiver engagement with the probation process has been emphasized. However, the potentially crucial factor of the working alliance between caregivers and JPOs has been understudied. Working alliance is a psychotherapeutic construct that describes the collaborative relationship formed between providers and clients, and existing research with various samples and psychotherapeutic approaches indicates small but robust associations between strong working alliance and positive treatment outcomes. At present, the study of working alliance and its association with outcomes within the juvenile justice system has utilized models drawn from adult psychotherapeutic literature that may not account for the unique purpose of the caregiver-JPO alliance nor the systemic factors that influence it. This qualitative study identified the mechanisms of alliance formation from the perspective of caregivers and proposes a model of caregiver-JPO alliance. Results of the qualitative interviews suggest that caregivers identified four key mechanisms of alliance formation and maintenance, Communication, Shared Understanding and JPO Responsivity, Collaborative Problem-Solving, and Follow-Through and Consistency, along with several external influences on alliances. The model is utilized to make recommendations for JPOs’ alliance-building actions with caregivers, and future research directions are suggested to address limitations of the current study and elucidate certain aspects of the proposed model