Some near horizon studies onWeyl and Vaidya spacetimes

This thesis comprises some studies on the Weyl, Vaidya and Weyl distorted Schwarzschild (WDS) spacetimes. The main focal areas are : a) construction of near horizon metric(NHM) for WDS spacetime and subsequently a "stretched horizon" prescribed by the membrane formalism for black holes, b) application of membrane formalism and construction of stretched horizons for Vaidya spacetime and c) using the thin shell formalism to construct an asymptotically flat spacetime with a Weyl interior where the construction does not violate energy conditions. For a), a standard formalism developed in [1] has been used wherein the metric is expanded as a Taylor series in ingoing Gaussian null coordinates with the affine parameter as the expansion parameter. This expansion is used to construct a timelike "stretched horizon" just outside the true horizon to facilitate some membrane formalism studies, the theory for which was first introduced in [2]. b) applies the membrane formalism to Vaidya spacetime and also extends a part of the work done in [1] in which event horizon candidates were located perturbatively. Here, we locate stretched horizons in close proximity to every event horizon candidate located in [1]. c) is an attempt to induce Weyl distortions with a thin shell of matter in an asymptotically flat spacetime without violating energy conditions.

Iron speciation and magnetic susceptibility in bottom sediments of the Black Sea, Core SMG91-903

12 cores of Late Pleistocene - Holocene deposits were studied. They were collected by gravity cores on the continental slope and in the deep-water part of the Black Sea within the Adler-Tuapse polygon. In four of them in New Euxinian deposits at the base of a packet of hydrotroilite laminae paleomagnetic anomalies likely resulting from the Gothenburg magnetic excursion occur. Comparison with results of similar studies in the western Black Sea, where the Gothenburg magnetic excursion was previously found, let to validate stratigraphic synchronism of the hydrotroilite horizon in the eastern and western parts of the Black Sea and to confirm the authors' views about peculiarities of paleogeographical development of the Black Sea basin in the Late Pleistocene - Holocene.

Safety and efficacy of ledipasvir-sofosbuvir in black patients with hepatitis C virus infection: A retrospective analysis of phase 3 data.

UNLABELLED: Black patients chronically infected with genotype 1 hepatitis C virus (HCV) have historically had lower rates of response to interferon-based treatment than patients of other races. In the phase 3 ION program, the single-tablet regimen of the NS5A inhibitor ledipasvir and NS5B nucleotide polymerase inhibitor sofosbuvir was shown to be safe and highly effective in the general population. The aim of this study was to evaluate the safety and efficacy of ledipasvir/sofosbuvir in black patients using data from the three open-label ION clinical trials, which evaluated the safety and efficacy of 8, 12, and 24 weeks of ledipasvir/sofosbuvir with or without ribavirin for the treatment of treatment-naïve and treatment-experienced patients with genotype 1 HCV, including those with compensated cirrhosis. The primary endpoint was sustained virologic response at 12 weeks after the end of therapy (SVR12). For our analysis, rates of SVR12, treatment-emergent adverse events, and graded laboratory abnormalities were analyzed in black versus non-black patients. Of the 1949 patients evaluated, 308 (16%) were black. On average, black patients were older, had higher body mass index, were more likely to be IL28B non-CC, and had a lower serum alanine aminotransferase at baseline than non-black patients. Overall, 95% of black and 97% of non-black patients achieved SVR12. The rate of relapse was 3% in black patients as compared with 2% in non-black patients. The most common adverse events included fatigue, headache, nausea, and insomnia. The majority of adverse events occurred more frequently in the ribavirin-containing arms of the studies. No differences were observed in overall safety by race. CONCLUSION: A once-daily dosage of ledipasvir/sofosbuvir was similarly effective in black and non-black patients with genotype 1 HCV infection. The addition of ribavirin did not appear to increase SVR12 but was associated with higher rates of adverse events.

Infused: Millennials and the Future of the Black Church

Deep societal trends impact the religious fervency and participation of millennials in the Black Church. Many young adults, though remaining Christian, have fallen away from their faith communities, finding them irrelevant for their daily lives. Even the most religiously committed have shown signs of waning faith, as evidenced by limited participation, and theological and ideological dissonance with the Black Church. Historically strong across all indicators, the Black Church is ideally positioned to stave off the attrition of youth and young adults, having a missional mindset toward this cohort—prioritizing them in their ministry development and programming. African American congregational leaders must develop disciples who have cohesive identities, live integrated lives, and experience an infusion of their personal vocation and the mission of the Church. Thus the future of the Black Church depends on the development of millennials who have an integrated faith life, which is distinguishable by its practices, disciplines, and virtues that are nurtured by an understanding of the Church’s mission and their role in it. Key will be establishing mentoring relationships that allow for questioning, exploration and discovery. To enact the changes necessary the church must understand the cultural worlds of young adults and engage them in holistic ministry that is reflective of the mission of God through Christ (missio dei)—activity that culminates with reaching the world with God’s redemptive plan for humanity.

Syndemic Health Disparities and Resilience Processes Related to HIV Transmission Risk among African American/Black Men in South Florida

Rates of HIV infection continue to climb among minority populations and men who have sex with men (MSM), with African American/Black MSM being especially impacted. Numerous studies have found HIV transmission risk to be associated with many health and social disparities resulting from larger environmental and structural forces. Using anthropological and social environment-based theories of resilience that focus on individual agency and larger social and environmental structures, this dissertation employed a mixed methods design to investigate resilience processes among African American/Black MSM. Quantitative analyses compared African American/Black (N=108) and Caucasian/White (N=250) MSM who participated in a previously conducted randomized controlled trial (RCT) of sexual and substance use risk reduction interventions. At RCT study entry, using past 90 day recall periods, there were no differences in unprotected sex frequency, however African American/Black MSM reported higher frequencies of days high (P Qualitative data collected among a sub-sample of African American/Black MSM from the RCT (N=21) described the men’s experiences of living with multiple health and social disparities and the importance of RCT study assessments in facilitating reductions in risk behaviors. A cross-case analysis showed different resilience processes undertaken by men who experienced low socioeconomic status, little family support, and homophobia (N=16) compared to those who did not (N=5). The dissertation concludes that resilience processes to HIV transmission risk and related health and social disparities among African American/Black MSM varies and are dependent on specific social environmental factors, including social relationships, structural homophobia, and access to social, economic, and cultural capital. Men define for themselves what it means to be resilient within their social environment. These conclusions suggest that both individual and structural-level resilience-based HIV prevention interventions are needed.

The Career Development of Black Female Chief Nurse Executives

This qualitative study was designed to explore the career development of Black female chief nurse executives. Although a small proportion of Black female nurses have achieved positions at the nurse executive level, there remains a paucity of Black female nurse executives in this crucial position which raised the question of what factors contributed to this lack of advancement, but, more important, what factors have contributed to the success of the few who have achieved such level of success in healthcare organizations. The purpose of the study was to explore the career paths of Black female chief nurse executives with a view of understanding the factors which both facilitate and hinder the career development of these leaders in healthcare organizations. The guiding research question was, How do Black female nurse executives in this sample describe their career development? The participants in this study were Black female chief nurse executives located throughout the United States who, for the most part, were raised in segregation with a strong family foundation. To collect data, semistructured telephone interviews were conducted with 10 Black female chief nurse executives throughout the United States. The transcripts from the interviews were transcribed, coded, and analyzed. Using Super’s (1990, 1996), and Gottfredson’s (1981, 1996, 2002, 2005) career development theories and critical race theory (Crenshaw, 1995; Delgado, 2000) as the theoretical framework, the researcher found that the participants’ career development was influenced by (a) strong support system, (b) guidance, (c) influence of diversity, and (d) servant leadership. The findings help us understand the factors that have contributed to their successes as Black chief nurse executives. With the increasingly diverse population and concurrent increasing diversity in nursing and concerns about healthcare disparities, it is imperative that organizations attract, hire, develop, retain, and advance qualified Black nurses. Future studies addressing not only the career development of Black nurses but nurses in general might be informed by the present study’s findings. Recommendations are offered for nursing practice, education, and organizational policy.

'A Kind of Logic, A Kind of Dominant Logic': Navigating Colonialism, Honoring Black Mobility, and Thinking on Moving Through

My thesis thinks through the ways Newtonian logics require linear mobility in order to produce narratives of progress. I argue that this linear mobility, and the resulting logics, potentially erases the chaotic and non-linear motions that are required to navigate a colonial landscape. I suggest that these non-linear movements produce important critiques of the seeming stasis of colonial constructs and highlight the ways these logics must appear neutral and scientific in an attempt to conceal the constant and complex adjustments these frameworks require. In order to make room for these complex motions, I develop a quantum intervention. Specifically, I use quantum physics as a metaphor to think through the significance of black life, the double-consciousness ofland, and the intricate motions of sound. In order to put forth this intervention, I look at news coverage of Hurricane Katrina, Du Bois’s characterization of land in Souls of Black Folks, and the aural mobilities of blackness articulated in an academic discussion and interview about post- humanism.

Biological Impacts and Uses of Black Bass Competitive Fishing Tournaments on Large Lake Systems

Recreational fisheries in North America are valued between $47.3 billion and $56.8 billion. Fisheries managers must make strategic decisions based on sound science and knowledge of population ecology, to effectively conserve populations. Competitive fishing, in the form of tournaments, has become an important part of recreational fisheries, and is common on large waterbodies including the Great Lakes. Black Bass, Micropterus spp., are top predators and among the most sought after species in competitive catch-and-release tournaments. This study investigated catch-and-release tournaments as an assessment tool through mark-recapture for Largemouth Bass (>305mm) populations in the Tri Lakes, and Bay of Quinte, part of the eastern basin of Lake Ontario. The population in the Tri Lakes (1999-2002) was estimated to be stable between 21,928-29,780, and the population in the Bay of Quinte (2012-2015) was estimated to be between 31,825-54,029 fish. Survival in the Tri Lakes varied throughout the study period, from 31%-54%; while survival in the Bay of Quinte remained stable at 63%. Differences in survival may be due to differences in fishing pressure, as 34-46% of the Largemouth Bass population on the Tri Lakes is harvested annually and only 19% of catch was attributed to tournament angling. Many biological issues still surround catch-and-release tournaments, particularly concerning displacement from initial capture sites. In the past, the majority of studies have focused on small inland lakes and coastal areas, displacing bass relatively short distances. My study displaced Largemouth and Smallmouth Bass up to 100km, and found very low rates of return; only 1 of 18 Largemouth Bass returned 15 km and 1 of 18 Smallmouth Bass returned 135 km. Both species remained near the release sites for an average of approximately 2 weeks prior to dispersing. Tournament organizers should consider the use of satellite release locations to facilitate dispersal and prevent stockpiling at the release site. Catch-and-release tournaments proved to be a valuable tool in assessing population variables and the effects of long distance displacement through the use of mark recapture and acoustic telemetry on large lake systems.

Effects of incomplete combustion on atmospheric chemistry: Black carbon climate forcing and global carbon monoxide emissions

This thesis is actually the composition of two separate studies aimed at further understanding the role of incomplete combustion products on atmospheric chemistry. The first explores the sensitivity of black carbon (BC) forcing to aerosol vertical location since BC has an increased forcing per unit mass when it is located above reflective clouds. We used a column radiative transfer model to produce globally-averaged values of normalized direct radiative forcing (NDRF) for BC over and under different types of clouds. We developed a simple column-weighting scheme based on the mass fractions of BC that are over and under clouds in measured vertical profiles. The resulting NDRF is in good agreement with global 3-D model estimates, supporting the column-weighted model as a tool for exploring uncertainties due to diversity in vertical distribution. BC above low clouds accounts for about 20% of the global burden but 50% of the forcing. We estimate maximum-minimum spread in NDRF due to modeled profiles as about 40% and uncertainty as about 25%. Models overestimate BC in the upper troposphere compared with measurements; modeled NDRF might need to be reduced by about 15%. Redistributing BC within the lowest 4 km of the atmosphere affects modeled NDRF by only about 5% and cannot account for very high forcing estimates. The second study estimated global year 2000 carbon monoxide (CO) emissions using a traditional bottom-up inventory. We applied literature-derived emission factors to a variety of fuel and technology combinations. Combining these with regional fuel use and production data we produced CO emissions estimates that were separable by sector, fuel type, technology, and region. We estimated year 2000 stationary source emissions of 685.9 Tg/yr and 885 Tg/yr if we included adopted mobile sources from EDGAR v3.2FT2000. Open/biomass burning contributed most significantly to global CO burden, while the residential sector, primarily in Asia and Africa, were the largest contributors with respect to contained combustion sources. Industry production in Asia, including brick, cement, iron and steel-making, also contributed significantly to CO emissions. Our estimates of biofuel emissions are lower than most previously published bottom-up estimates while our other fuel emissions are generally in good agreement. Our values are also universally lower than recently estimated CO emissions from models using top-down methods.

Ready for Transition: Factors that facilitate transfer to undergraduate engineering programs among Black African and American students

This study examines the factors facilitating the transfer admission of students broadly classified as Black from a single community college into a selective engineering college. The work aims to further research on STEM preparation and performance for students of color, as well as scholarship on increasing access to four-year institutions from two-year schools. Factors illuminating Underrepresented Racial and Ethnic Minority (URM) student pathways through Science, Technology, Engineering, and Mathematics (STEM) degree programs have often been examined through large-scale quantitative studies. However, this qualitative study complements quantitative data through demographic questionnaires, as well as semi-structured individual and group. The backgrounds and voices of diverse Black transfer students in four-year engineering degree programs were captured through these methods. Major findings from this research include evidence that community college faculty, peer networks, and family members facilitated transfer. Other results distinguish Black African from Black American transfers; included in these distinctions are depictions of different K-12 schooling experiences and differences in how participants self-identified. The findings that result from this research build upon the few studies that account for expanded dimensions of student diversity within the Black population. Among other demographic data, participants’ countries of birth and years of migration to the U.S. (if applicable) are included. Interviews reveal participants’ perceptions of factors impacting their educational trajectories in STEM and subsequent ability to transfer into a competitive undergraduate engineering program. This study is inclusive of, and reveals an important shifting demographic within the United States of America, Black Africans, who represent one of the fastest-growing segments of the immigrant population.

ABLE-BODIED WOMANHOOD: DISABILITY AND CORPOREALLY EXCLUSIONARY NARRATIVES IN BLACK AND WHITE WOMEN’S RIGHTS DISCOURSES, 1832-1932

This project is a feminist disability rhetorical analysis of US black and white women’s rights movements from 1832-1932. Guided by Disability and Feminist Theory, it works to identify the presence and use of patterns of disability tropes in women’s rights discourses. From Lucretia Coffin Mott to Sojourner Truth, Elizabeth Cady Stanton to Mary Church Terrell, and Charlotte Perkins Gilman to Addie Hunton, this project interrogates the rhetorical work of dominant narratives and lesser known voices in women’s rights discourses. I argue that early black and white women’s rights advocates often utilized and repeated a disability rhetoric that relied on disability metaphor, narrative prosthesis, and corporeally exclusionary narratives in order to construct definitions of womanhood. Their insistence on cognitive ability as a marker of “fitness” and “ability” provided the foundation for rights arguments based on ableist assumptions of autonomy and citizenship. I also argue that this use of disability rhetoric relied on and furthered a pervasive ableist ideology present not only in many of these movements, but in US society. In the process, US black and white women’s rights discourses have continually elided women with disabilities from women’s rights discourses because their bodies (physically, cognitively, and/or psychologically) did not meet the ableist prerequisites set for claiming women’s rights during this time period.

BLACK, MALE, AND HIGH-ACHIEVING: AN EXAMINATION OF A RISK FACTOR AND CULTURAL RESOURCES FOR BLACK MALE ACADEMIC ACHIEVEMENT

Black boys are confronted with unique educational circumstances. They are often misdiagnosed and misplaced into special education programs (Bush-Daniels, 2008; Patton, 1998; Terman et al., 1996). Additionally, they are less likely to be enrolled in gifted and talented programs, even if their former achievements reflect their aptitude to succeed (Black Alliance for Educational Options, n.d.; Moore & Flowers, 2012). Given these statistics, a considerable emphasis has been placed on the causes and the consequences of low/under achievement for this population. As a result, the experiences of Black males who are achieving have been greatly neglected. Moreover, little is known about the factors that facilitate academic achievement among high-achieving Black boys. In an effort to bring the heterogenic nature of schooling experiences for Black boys to light, the present study examined the influence risk and protective factors had on the academic experiences of high-achieving Black boys. Grounded in the risk and resilience framework and the Integrative Model for the Study of Minority Youth Development, this study explored whether the high-achieving Black high school boys in this sample (n =88) reported experiencing discrimination (i.e. academic-based) and how this academic-based discrimination related to their 1) academic performance (i.e. GPA), 2) perceptions of math ability, and 3) race-based academic self-concept. In addition to exploring how academic-based discrimination was linked to academic achievement, this study examined how cultural resources such as racial socialization messages and racial identity related to academic achievement. Specifically, cultural socialization, preparation for bias, egalitarianism, private regard and public regard were evaluated alongside the three academic outcomes under study. Finally, the study explored whether aspects of racial socialization or racial identity buffered the effects of discrimination on any of the outcomes. Interestingly, the race/ethnicity of the student mattered for how students perceived their math ability. The risk factor academic-based discrimination was linked to academic performance. Cultural resources cultural socialization, preparation for bias, and private regard were linked to various academic outcomes of interest. There was only one significant moderating effect: a high private regard buffered the relationship between academic-based discrimination and race-based academic self-concept. Limitations and implications of this study are discussed.

The New Bottom Line: Black Women Cultural Entrepreneurs Re-Define Success in The Connected Economy

Black women cultural entrepreneurs are a group of entrepreneurs that merit further inquiry. Using qualitative interview and participant observation data, this dissertation investigates the ways in which black women cultural entrepreneurs define success. My findings reveal that black women cultural entrepreneurs are a particular interpretive community with values, perspectives and experiences, which are not wholly idiosyncratic, but shaped by collective experiences and larger social forces. Black women are not a monolith, but they are neither disconnected individuals completely devoid of group identity. The meaning they give to their businesses, professional experiences and understandings of success are influenced by their shared social position and identity as black women. For black women cultural entrepreneurs, the New Bottom Line goes beyond financial gain. This group, while not uniform in their understandings of success, largely understand the most meaningful accomplishments they can realize as social impact in the form of cultural intervention, black community uplift and professional/creative agency. These particular considerations represent a new paramount concern, and alternative understanding of what is typically understood as the bottom line. The structural, social and personal challenges that black women cultural entrepreneurs encounter have shaped their particular perspectives on success. I also explore the ways research participants articulated an oppositional consciousness to create an alternative means of defining and achieving success. I argue that this consciousness empowers them with resources, connections and meaning not readily conferred in traditional entrepreneurial settings. In this sense, the personal, social and structural challenges have been foundational to the formation of an alternative economy, which I refer to as The Connected Economy. Leading and participating in The Connected Economy, black women cultural entrepreneurs represent a black feminist and womanist critique of dominant understandings of success.

Nervous Kitchens: Critical Readings of Black Women's Food Practices in The Soul Food Imaginary

Nervous Kitchens intervenes in the story of soul food by treating the kitchen as a central site of instability. These kitchens reveal and critique their importance to constructions of Black womanhood. Utilizing close readings of Black women’s culinary practices in popular televisual kitchens and archival analysis of USDA domestic reforms, the project locates sites that challenge how we oversimplify soul food as a Black cultural product. These oversimplifications come through what I term the soul food imaginary. This term underscores how the cuisine is tangible (i.e., how dishes are made) but also the ways that histories of enslavement, migration, and domesticity are disseminated through fictionalized representations of Black women in the kitchen offering comfort through food. The project explores how images of these kitchens adhere to and diverge from the imaginary's four conventions: (1) Soul food originates in enslavement where master’s scraps became mama’s meal time; (2) Soul food is not healthy food; (3) Soul food moves South to North uninterrupted during the Great Migration and is evidence of and fuel for struggle, survival, and transformation; and 4) Black women cook it the best, naturally, and alone in the kitchen.

Genetic evidence for polygynandry in the black-striped pipefish syngnathus abaster: a microsatellite-based parentage analysis

Sexual selection theory predicts that, in organisms with reversed sex roles, more polyandrous species exhibit higher levels of sexual dimorphism. In the family Syngnathidae (pipefish, seahorses, and seadragons), males provide all parental care by carrying developing embryos on their ventral surfaces, and females develop secondary sex characters. Syngnathids exhibit a variety of genetic mating patterns, making them an ideal group to test predictions of sexual selection theory. Here, we describe the mating system of the black-striped pipefish Syngnathus abaster, using 4 highly variable microsatellites to analyze parentage of 102 embryos. Results revealed that 1) both sexes mate multiple times over the course of a pregnancy (polygynandrous mating system), 2) eggs are spatially segregated by maternity within each brood pouch, and 3) larger females have higher mating success (Kolmogorov–Smirnov test; P < 0.05). Together with similar studies of other syngnathid species, our results support the hypothesis that the mating system is related to the intensity of sexual dimorphism.